Acute Injuries

There is a distinct advantage for repairing completely disrupted PL structures and meniscal attachments in acute injuries (Fig. 22-3). At the time of surgery, extensive disruption of these structures is observed. Careful dissection is required to identify anatomic tissue planes and maintain an intact vascular and neural supply. The so-called golden period to perform an acute surgical repair is within 7 to 14 days of the injury. After this time, scar tissue will obliterate tissue planes and make the dissection and repair difficult.

FIGURE 22-3 Algorithm for treatment of acute injuries to the PL structures. B-PT-B, bone–patellar tendon–bone; FCL, fibular collateral ligament; PFL, popliteofibular ligament; POP, popliteus.

A lower extremity venous ultrasound is obtained before surgery in acute multiligament knee injuries that have swelling and soft tissue damage to detect occult venous thrombosis that requires urgent treatment and contraindicates surgery. An initial delay in surgery for 5 to 7 days allows for observation of the neurovascular status, soft tissue swelling, skin integrity, and some clearing of hemorrhage in soft tissues in the injured extremity.

During this time, the lower extremity is supported in a soft hinged full-leg brace in extension with a well-padded compression dressing. In knees with extensive damage to the PL structures and PCL, a bivalved cylinder cast with a posterior plaster shell and posterior foam calf pad may be required to provide added stability and prevent posterior tibial subluxation. Reduction of the tibiofemoral joint is verified by a lateral radiograph. Lower limb elevation, ice, and compression are important. The physical therapist initiates early protected knee motion, patellar mobilization, active quadriceps function, and electrical muscle stimulation. Dislocated knees scheduled for surgery require vascular consultation, ankle/brachial studies (ankle/brachial index ≥ 90%), and possible arteriography to exclude arterial injuries, even when intact peripheral pulses are present.

Contraindications to acute surgical repair are excessive soft tissue swelling, hemorrhage, and edema that are frequently present in dislocated knees with multiple ligament ruptures. The operative procedure adds to the injury by increasing edema and soft tissue swelling, risk of infection, vascular problems (including compartment syndromes), and skin flap necrosis. In these cases, it is preferable to treat the acute injury and perform ligament reconstructive procedures later after tissue swelling is resolved and muscle function and knee motion have been restored.

In addition, there is a significant incidence of knee arthrofibrosis after acute surgical treatment of knee dislocations, which is lessened with a staged approach. In the authors’ experience, only approximately one in four dislocated knees with associated PL ruptures are candidates for acute surgical procedures. A delay in surgical reconstruction results in a decreased incidence of knee arthrofibrosis and markedly improves surgical outcomes. Other obvious contraindications include open wounds and skin abrasions.

Magnetic resonance imaging (MRI) provides important information regarding ligament ruptures, articular cartilage damage, and meniscus tears. Frequently, the sites of rupture to the FCL, popliteus muscle and tendon, PFL, and meniscal attachments may be identified before surgery. One note of caution is that the tendency exists, owing to edema and swelling in the PL tissues, to misinterpret the MRI and conclude that there is greater tissue damage and disruption than is actually encountered at surgery.

Chronic Injuries

Patients with chronic knee injuries that present with severe muscle atrophy require several months of preoperative rehabilitation. Patients with a hyperextension gait abnormality must complete a gait-retraining program,⁴³ described in detail in Chapter 34, Correction of Hyperextension Gait Abnormalities: Preoperative and Postoperative Techniques. This program is done in addition to lower extremity muscle strengthening exercises. In the authors’ experience, patients will convert to a more normal gait pattern after 4 to 6 weeks of training. More time is required for severe quadriceps atrophy before surgical intervention.

Varus osseous malalignment must be corrected before chronic PL reconstruction, as described previously. Failure to address this malalignment will greatly increase the risk of failure of any PL procedure (Fig. 22-4). In some cases in which the PL deficiency is due to interstitial stretching of the tissues and not a traumatic rupture, a simplified proximal advancement of the PL structures may be performed with the HTO. In anatomic PL reconstructions, the ligament surgery is staged after healing of the HTO. The indications for the various PL procedures are described in detail under the “Operative Treatment of Acute PL Ruptures” and “Operative Treatment of Chronic PL Ruptures” sections.

FIGURE 22-4 Standing anteroposterior (AP; A) and lateral (B) radiographs of a 28-year-old man referred to the authors’ center 14 months after failure of an acute repair of the PL structures and posterior cruciate ligament (PCL) allograft reconstruction. The patient had underlying varus osseous malalignment, which likely was a factor in the failure of the ligament reconstructions. This malalignment requires correction before revision surgery.

(A and B, From Noyes, F. R.; Barber-Westin, S. D.: Posterior cruciate ligament revision reconstruction, part 1: causes of surgical failure in 52 consecutive operations. Am J Sports Med 33:646–654, 2005.)

Patients who have undergone prior lateral meniscectomy and who demonstrate early tibiofemoral arthritis are considered for lateral meniscus transplantation.⁴¹

Cruciate Graft Reconstruction

The majority of patients who undergo PL reconstruction require a concomitant ACL or PCL reconstruction (Fig. 22-5). The appropriate grafts for the cruciate procedures should be determined; autogenous tissues with bony fixation are preferred. However, the surgeon should ensure that B-PT-B and Achilles tendon–bone (AT-B) allografts are available the day of surgery. These will be required if autogenous tissue is unavailable or not suitable for the PL or cruciate procedures.

FIGURE 22-5 Algorithm for treatment of chronic injuries to the PL structures. B-PT-B, bone–patellar tendon–bone; FCL, fibular collateral ligament; PFL, popliteofibular ligament.

Operative Setup and Patient Positioning

The patient is instructed to use a soap scrub of the operative limb (“toes to groin”) the evening before and the morning of surgery. Lower extremity hair is removed by clippers, not a shaver. Antibiotic infusion is begun 1 hour before surgery. A nonsteroidal anti-inflammatory drug (NSAID) is given to the patient with a sip of water upon arising the morning of surgery (which is continued until the 5th postoperative day unless there are specific contraindications to the medicine). The use of a NSAID and a postoperative firm double-cotton, double-Ace compression dressing for 72 hours (cotton, Ace, cotton, Ace layered dressing) has proved very effective in diminishing soft tissue swelling and is used in all knee surgery cases. In complex multiligament surgery, the antibiotic is repeated at 4 hours and continued for 24 hours. A urinary indwelling catheter is not used unless there are specific indications. The patients’ urinary output and total fluids are carefully monitored during the procedure and in the recovery room. The knee skin area is initialed by both the patient and the surgeon before entering the operating room, with a nurse observing the procedure. The identification process is repeated with all operative personnel with a “time out” before surgery to verify the knee undergoing surgery, procedure, allergies, antibiotic infusion, and special precautions that apply. All personnel provide verbal agreement.

The patient is placed supine on the operative table and appropriately padded. The knee portion of the table is flexed 20°, and the table is tilted into a mild Trendelenburg position. A posterior thigh pad is placed behind the proximal thigh to suspend the knee joint at 20° to 30° of flexion. No pressure is exerted on the posterior popliteal space, allowing the posterior neurovascular tissues and popliteal tissues to drop posteriorly away from the operative approach. A common mistake is to place a posterior bolster in the popliteal space that pushes the posterior neurovascular structures into the operative dissection.

In cases of acute dislocation or any questionable vascular status, the entire lower limb is draped free to allow vascular checks of the anterior and posterior tibial pulses at the foot during the operative procedure.

An initial arthroscopic examination is performed under low-pressure conditions with a free or controlled open outflow to prevent fluid extravasation. The arthroscopic examination confirms damage to intra-articular structures and allows photographic documentation of the injury. Appropriate meniscus surgery is performed as required with the exception that lateral meniscus repairs are done after the open exposure. If a leg holder is used, it is removed for the open surgery.

The tourniquet is placed at the proximal portion of the thigh with appropriate padding. The tourniquet is inflated (275–300 mm Hg) during the initial exploration of the ligamentous injury and identification of the common peroneal nerve (CPN). The tourniquet is deflated for the remainder of the procedure. The surgeon may elect to be seated, directly facing the lateral aspect of the knee, with a headlight in place that allows for careful dissection of the lateral soft tissues including the CPN.

Identification of Ligament and Soft Tissue Rupture Pattern

A 10- to 12-cm skin incision is made in a straight line centered over the joint line and 1 cm posterior to the iliotibial band (ITB) attachment at the tibia (Fig. 22-6A). After careful mobilization of the skin flaps, the ITB, biceps tendon, and lateral structures are encountered.

FIGURE 22-6 PL surgical technique. A, Site for the skin incision. B, Incision site in the interval between the posterior edge of the iliotibial band (ITB) and the anterior edge of the biceps tendon. C, In chronic cases with severe scarring, it may be necessary to add an anterior incision and displace the ITB posteriorly during the reconstructive procedure to allow better exposure. D, With the ITB retracted anteriorly, the interval between the lateral head of the gastrocnemius and the PL aspect of the capsule is opened bluntly, just proximal to the fibular head, without entering the joint capsule proximally.

Prior to dissection of the lateral aspect of the knee, the location of the CPN must be identified. If the CPN cannot be easily palpated and its course determined, then it is necessary at this point to expose and identify the nerve, which is discussed in the next section.

In the majority of knees, the ITB will be intact or demonstrate only partial tearing. In select cases, the ITB will be completely disrupted at the joint line or avulsed off its tibial attachment at Gerdy’s tubercle. Posteriorly, there are capsular attachments of the ITB, including fascial attachments to the short head of the biceps femoris, which are identified for later repair if torn. If the ITB is intact, an incision is made along its posterior border to allow visualization of all of the underlying structures (see Fig. 22-6B).

The lateral capsular tissues and meniscal attachments are the next structures visualized. A vertical incision is made into the anterior third of the capsule and extended to the lateral meniscus just anterior to the popliteus tendon attachment. The popliteus tendon and meniscus attachments at the femoral popliteal recess are identified. Frequently, it is necessary to repair the superior and inferior meniscal fasciculi (Fig. 22-7) to restore meniscal attachments to the lateral meniscus. Careful varus stress is placed on the knee joint to allow inspection of the lateral meniscus attachments and tibiofemoral articular cartilage. On occasion, an additional anterior incision is required for visualization of underlying anatomy (see Fig. 22-6C).

FIGURE 22-7 Illustration of the popliteus tendon and its surrounding popliteomeniscal fascicles and lateral meniscus attachments that are frequently disrupted, requiring repair.

Critical Points OPERATIVE TREATMENT OF ACUTE POSTEROLATERAL RUPTURES: IDENTIFICATION OF LIGAMENT AND SOFT TISSUE RUPTURE PATTERN

• Skin incision straight line 10–12 cm in length, centered over joint line, 1 cm posterior to the ITB attachment at tibia.

• Intact ITB: incision along its posterior border to allow anterior displacement, visualize all underlying structures.

• Small bursa located superficial and anterolateral to distal portion of FCL: open to allow better exposure of FCL attachment.

• Proximal one third of posterior capsule attaches to proximal portion of gastrocnemius muscle and fabellum.

• Interval between posterior capsule and gastrocnemius tendon entered just above fibula.

Exposes PL structures, popliteus muscle tibial attachments, popliteus muscle tendon junction, PFL, popliteus tendon attachment at the femur, fabellofibular ligament.

FCL, fibular collateral ligament; ITB, iliotibial band; PFL, popliteofibular ligament; PL, posterolateral.

The fibular head and attachments of the biceps femoris short and long head are the next structures visualized, which have been described in detail in Chapter 2, Lateral, Posterior, and Cruciate Knee Anatomy. The two tendinous components (direct and anterior arms) and one of the fascial components (lateral aponeurotic expansion) make up the key portion of the long head anatomy. The other fascial components are the reflected arm and the anterior aponeurotic expansion.

The most proximal component is the reflected arm. It originates just proximal to the fibular head and ascends anteriorly to insert on the posterior edge of the ITB. The direct arm inserts onto the PL edge of the fibula just distal to the tip of the styloid. A portion of the anterior arm inserts onto the lateral aspect of the fibular head, and the rest continues distally just lateral to the FCL. Portions of the anterior arm ascend anteriorly forming the lateral aponeurotic expansion that attach to the posterior and lateral aspects of the FCL. Here, a small bursa separates the anterior arm from the distal fourth of the FCL. The anterior arm thus forms the lateral wall of this bursa (see Fig. 2-12). This is an important surgical landmark, because a small horizontal incision can be made here, 1 cm proximal to the fibular head, to enter this bursa and locate the insertion of the FCL into the fibular head. The anterior arm then continues distally over the FCL, forming the anterior aponeurosis, which covers the anterior compartment of the leg. The primary areas of injury are tendon avulsions off of the fibula, which often have a major osseous component that can be repaired. In addition, the fascial extensions anteriorly and laterally are repaired.

The short head of the biceps courses just deep (or medial) and anterior to the long head tendon, sending a majority of its proximal muscular fibers to the long head tendon itself.⁵³ It has six distal attachments, described in detail in Chapter 2, Lateral, Posterior, and Cruciate Knee Anatomy. The most important attachments are that of the direct arm, the anterior arm, and the capsular arm.

The capsular arm originates just prior to the short head reaching the fibula and continues deep to the FCL to insert onto the PL knee capsule and fabella. Here the fibers of the capsular arm continue distally as the fabellofibular ligament. Just distal to the capsular arm, a capsulo-osseous layer forms a fascial confluence with the ITB (the biceps–capsulo-osseous iliotibial tract confluent). The direct arm of the short head inserts onto the fibular head just posterior and proximal to the direct arm of the long head tendon. The anterior arm then continues medial or deep to the FCL, partially blends with the anterior tibiofibular ligament, and inserts onto the tibia 1 cm posterior to Gerdy’s tubercle. This site is also the attachment of the midthird lateral knee capsule. The lateral aponeurotic expansion of the short head inserts onto the medial aspect of the FCL. The FCL may be torn at its femoral attachment or within its substance or avulsed along with the biceps attachment at the fibula.

Proceeding posteriorly, the next structure encountered is the lateral gastrocnemius muscle tendinous attachment to the femur. The proximal third of the posterior capsule attaches to the proximal portion of the gastrocnemius muscle and fabellum (osseous or cartilagenous analog).

The interval between the posterior capsule and the gastrocnemius tendon is entered just above the fibula, similar to the exposure for a lateral meniscus repair. This exposes the popliteus muscle tibial attachments, popliteus muscle-tendon junction, PFL, popliteus tendon attachment at the femur, and fabellofibular ligament (extension of short head biceps attachments) (see Fig. 22-6D).

In dissection studies, LaPrade and coworkers¹⁹ described a fabellum (osseous or cartilagenous) present in all specimens. This structure forms an attachment for the oblique popliteal ligament and fabellofibular ligament, which along with the posterior capsule, are important restraints for limiting knee hyperextension. Although individual capsular components and structures are difficult to discern with extensive capsular ruptures, it is important to repair disrupted posterior capsular tissues after completion of the initial dissection.

Peroneal Nerve Identification

It is important at the initial stages of the dissection to palpate and determine the location of the CPN. To expose the CPN, it is safest to begin in the proximal aspect of the operative exposure. A large retractor is used to elevate the muscular portion of the biceps femoris, placing the fascial tissues beneath the biceps muscle under gentle tension. This gentle upward displacement of the biceps muscle is key to visualize and dissect the CPN, because its normal curviform undulations are removed and it assumes a straighter appearance (Fig. 22-8A). The investing crural fascia is incised over the CPN to the fibula.

FIGURE 22-8 Exposure of the common peroneal nerve (CPN). A, Proximal exposure of the CPN inferior to the long head of the biceps tendon. B, The superficial fascia over the peroneus longus is incised. C, The peroneus longus muscle at the fibular neck is partially incised adjacent to the CPN. D, Complete exposure of the CPN entering into the anterolateral compartment. In this knee, the CPN is shown to be distinctly abnormal and edematous at this site. The CPN is not displaced from its normal anatomic site to protect the vascular supply.

The CPN and its branches are not removed from their normal anatomic position to avoid damaging the delicate blood supply, particularly in the region where the CPN approaches and then passes around the fibular neck. Kadiyala and associates¹⁶ reported measurements in cadaveric specimens of the blood supply to the CPN in the popliteal fossa and fibular neck region. These authors hypothesized that the susceptibility of the CPN to injury or lack of a response to operative treatment when injured may be related to deficiencies in intraneural and extraneural vascular supply and anastomoses.

The most common source of blood supply to the proximal portion of the CPN is a direct branch of the popliteal artery. This branch divides into proximal and distal anastomotic vessels that run in the connective tissue sheath of the nerve and anastomoses with the anterior recurrent tibial artery. The vessels, located in the epineurium, give rise to many small vessels of fine caliber, which extend 20 to 30 mm within the substance of CPN. It is important not to disturb this blood supply. Kadiyala and associates¹⁶ noted that the blood supply of the CPN was somewhat sparse with poor vascularization. A connection of the vasa nervorum was not found from the geniculate arteries, but occasional contributions from muscular branches were recognized (Fig. 22-9).

FIGURE 22-9 A, Gross dissection of the popliteal fossa of the right leg. The vessel branching from the popliteal artery gives rise to vasa nervorum to the tibial nerve and CPN and a branch that bifurcates into a vessel accompanying the sural nerve and the epineurial vessel running with the CPN. B, The major vascular arrangements supplying the CPN in the popliteal fossa.

(A and B, Adapted from Kadiyala, R. K.; Ramirez, A.; Taylor, A. E.; et al.: The blood supply of the common peroneal nerve in the popliteal fossa. J Bone Joint Surg Br 87:337–342, 2005.)

Bottomley and colleagues³ reviewed the anatomic position of the CPN in 54 patients who had damage to the PL structures. The CPN was noted to be displaced out of its normal position in 16 of 18 patients who had biceps avulsions or associated fibular head fractures. These authors advised that the surgeon should expect an abnormal nerve position on surgical exploration in knees with bone or soft tissue avulsion from the fibular head and the potential for iatrogenic damage.

Rubel and coworkers⁴⁹ conducted an anatomic investigation of the CPN in 31 cadaveric limbs by dissecting the CPN to its intramuscular branches. The authors described Gerdy’s safe zone as the area where the CPN and anterior recurrent branch defined an arc with an average radius of 45 mm. The distance between the fibular head and Gerdy’s tubercle was used to determine the radius of the safe zone. Therefore, this region in the proximal aspect of the tibia is advantageous for surgical exploration, because damage to the peroneal nerve and its branches is avoided (Fig. 22-10). The CPN divides into three branches as it enters the anterolateral musculature, with the anterior recurrent branch more proximal to the superficial and deep peroneal branches.

FIGURE 22-10 A, Cadaveric dissection of a fresh tissue specimen shows the circumferential area free of neural structures at the level of the proximal aspect of the tibia. The center of this circumference is located at Gerdy’s tubercle with an average radius (and standard deviation) of 45.32 ± 2.6 mm. d II, distance from the most prominent aspect of Gerdy’s tubercle to the starting point of the superficial branch of the CPN; d III, distance from the most prominent aspect of Gerdy’s tubercle to the anterior recurrent branch of the nerve. B, Gerdy’s safe zone marked preoperatively. Note how the marking follows the contour of the surface in a three-dimensional fashion on the lateral (B) and frontal (C) photographs.

(A–C, From Rubel, I. F.; Schwarzbard, I.; Leonard, A.; Cece, D.: Anatomic location of the peroneal nerve at the level of the proximal aspect of the tibia: Gerdy’s safe zone. J Bone Joint Surg Am 86:1625–1628, 2004.)

Dellon and associates⁹ reported on the anatomic variations of the CPN at the fibular head in 29 cadavers (bilaterally) and 65 patients treated with a CPN decompression for symptoms. Three possible anatomic variants were described that require attention and decompression in chronic neuropathies for a successful outcome. First, the superficial fascia of the superficial head of the peroneus longus muscle is divided by a proximal and distal transection of the fascia (found in 30% of cadavers and 78% of patients; see Fig. 22-8B). Second, when the peroneus longus muscle at the fibular neck is partially incised adjacent and superior to the CPN and the peroneus muscle lifted anteriorly, a fibrous band may be found that requires release (soft tissue restriction found in 43% of cadavers and 20% of patients; see Fig. 22-8C). Third, there may be a fibrous connection between the peroneus longus and the soleus muscle requiring division (found in 9% of cadavers and 6% of patients). These authors advise that after CPN decompression, the surgeon’s index finger should be able to gently pass along the CPN and into the anterolateral compartment (see Fig. 22-8D).

In cases of partial to complete peroneal nerve injury, it is important that added trauma to neural tissues be avoided. The goal is to identify the nerve pathway to avoid further damage during the ligament reconstructive procedure. The CPN passage into the lateral and anterolateral compartment at the entrance of the peroneal longus muscle at the fibular neck is a potential area for nerve compression. This area requires identification and division of variant fascial tissue bands, as previously described. Further CPN dissection is avoided.

Surgical Repair and Reconstruction of Acutely Disrupted Ligaments and Soft Tissues

The key to restore function to the disrupted PL structures, muscle attachments, and lateral meniscus attachments is a meticulous dissection, identification of damaged tissues, and repair of all injured structures. There does exist an unacceptably high risk of failure of primary repairs of disrupted PL structures, particularly the FCL, owing to high lateral tensile forces exerted on these tissues postoperatively.⁵⁰ Therefore, it is necessary to reconstruct one or more disrupted PL structures with an autograft or allograft, as is described. This adds tissue integrity and sufficient repair strength to resist LJO and external tibial rotation in the initial healing period of 4 to 6 postoperative weeks.

Critical Points OPERATIVE TREATMENT OF ACUTE POSTEROLATERAL RUPTURES: SURGICAL REPAIR AND RECONSTRUCTION OF ACUTELY DISRUPTED LIGAMENT AND SOFT TISSUES

• Unacceptably high risk of failure of primary repairs of disrupted PL structures owing to high lateral tensile forces postoperatively.

• Less severe injuries: FCL reconstructed, other PL soft tissues and PMTL repaired.

• Severe injuries: graft reconstruction FCL and PMTL may be necessary.

• Surgical approach, order of repair

Prefer B-PT-B autograft or allograft replacement of FCL.

Graft provides secure bone fixation, prevents abnormal joint displacements, allows early protected knee motion.

Graft provides the cornerstone for repair of other PL structures.

Operative repair starts with deep structures and proceeds to superficial structures.

B-PT-B, bone–patellar tendon–bone; FCL, fibular collateral ligament; PL, posterolateral; PMTL, popliteus muscle-tendon-ligament.

In less severe injuries, the FCL is reconstructed and the other PL soft tissues and PMTL are treated by primary repair. The FCL graft reconstruction resists lateral tibiofemoral compartment opening and PL subluxation, protecting the overall repair process during the initial healing stage. In more severe injuries, a graft reconstruction of both the FCL and the PMTL may be necessary. The reconstruction procedures are discussed in detail under “Operative Treatment of Chronic Ruptures,” later in this chapter.

Surgical Approach and Order of Surgical Repair

The surgical approach favored is a graft reconstruction of the FCL with either a B-PT-B autograft or allograft or an AT-B allograft. The authors were the first to describe a femoral-fibular reconstruction,³⁷ which is a second option and is described later in this chapter. The FCL fibers (unless directly avulsed at their insertion) are too disrupted to perform a primary repair. The FCL reconstruction provides for secure fixation, prevents abnormal joint displacements in the immediate postoperative period, and allows for early protected knee motion. These procedures are not difficult because the attachment sites on the femur and fibula are easily identifiable. Importantly, the graft provides the cornerstone about which the remainder of the soft tissue repair of the PL structures is performed. A B-PT-B graft requires an appropriate length graft, which may not always be obtained. Alternative graft options are AT-B or quadriceps tendon–patellar bone (QT-PB). The bone portion of these grafts may be placed at either the FCL fibular attachment or the FCL femoral attachment, and the tendon may be placed within a tunnel at the other attachment site. If a soft tissue tendon graft is selected, the graft is passed through a fibular tunnel (anterior-to-posterior), the tendon is sutured back upon itself, and a soft tissue interference fibular screw may be added.

After all of the anatomic structures and rupture sites are identified and carefully exposed, the order of the operative repair starts with deeper structures and proceeds to superficial structures. Examples of an acute operative repair are shown in Figures 22-11 and 22-12.

1 Meniscofemoral and tibial capsular repairs

Meniscus attachment repair.

FCL reconstruction with femoral and fibular tunnel placement and graft fixation.

Posterior capsule repair with sutures tied with the knee in full extension.

2 PMTL repair options

Musculotendinosus repair with direct suture (backup by FCL reconstruction).

PFL primary repair (tissues often of poor quality; FCL graft provides suitable tissue for additional sutures).

Popliteus tendon femoral attachment: avulsion (although rare) may be reattached.

Repair of disrupted biceps attachments: ITB repair of distal insertion, posterior femoral attachments, patellar retinaculum.

FIGURE 22-11 Acute repair of rupture to the PL structures. A, Lateral approach; anterior and posterior incisions have been made into the ITB. Sutures are placed to repair the lateral meniscus tibial attachments. B, FCL reconstruction with a B-PT-B allograft and suture of the PFL to the fibula. The popliteus tendon attachment at the femur was intact. C, Fixation of the FCL graft at the femoral and tibial anatomic attachments. D, Repair of PL capsule, biceps attachments, and posterior ITB.

FIGURE 22-12 Acute disruption of PL structures with avulsion of biceps and FCL from fibula. A, Magnetic resonance imaging (MRI) shows avulsion of biceps and FCL from fibular head. B, Initial arthroscopic procedure 10 days after injury, performed under low pressure and volume conditions. C, Surgical exploration shows avulsion of the ITB from tibial insertion and biceps, FCL attachment to fibula. The CPN was identified to be in a normal anatomic position. D, Repair of capsular attachments and ITB (sutures). Guide pin placed in the proximal fibula for screw and washer fixation of the biceps and FCL. E, AP postoperative radiograph shows fixation of the biceps and FCL to the proximal fibula, four-prong staple for ITB attachment to tibia, soft tissue anchor for deep capsular attachments.

Overview of Operative Options

The surgical options in knees with chronic injuries to the PL structures are based on the quality and integrity of these tissues determined at the initial surgical dissection. The surgical approach is similar to that described for acute dissection of the PL structures. The ITB is incised in the anterior and posterior planes to allow complete exposure. In chronic instabilities, the ITB may be lax and nonfunctional. In such knees, the attachment at Gerdy’s tubercle is osteotomized, and at the conclusion of the operative procedure, the proximal ITB attachments (lateral intermuscular septum, femoral posterior attachments) are sutured and the ITB osseous attachment is advanced distally by staple fixation to the tibia. The importance of identification of meniscus attachments, PMTL attachment, PL capsular structures, the biceps short and long head attachments, and the peroneal nerve has been previously discussed.

Markolf and colleagues^28–30 reported a series of cadaveric studies on the effect of a nonanatomic PL ligament reconstruction in restoring stability to a PCL-reconstructed knee. The PL reconstructions involved an FCL graft and either a popliteus tendon femoral-tibial reconstruction or a popliteus femoral-fibular PFL graft. The isometric attachment points for the graft were determined at surgery by taking the knee through flexion-extension and measuring the length changes at the attachment sites. The authors selected a femoral popliteus tendon graft placement that was 11 mm anterior and 2.7 mm proximal to the native popliteus femoral footprint. This nonanatomic placement, based on their isometric techniques, raises questions as to the application of the data to clinical surgical techniques. Each graft was tensioned in neutral tibial rotation, with 30 N of load placed on each of the grafts. This loading resulted in a markedly overconstrained internal tibial rotation and varus knee position throughout knee flexion. The authors concluded that additional studies were necessary because there is no consensus on the graft tensioning routine for PL reconstructions.

The approach advocated in this chapter is an anatomic FCL reconstruction in which the native anatomic site of the PL structure is replaced with a graft. The FCL may be deficient from prior disruption or replaced with scar tissue in which a well-defined structure cannot be identified. An FCL reconstruction provides a cornerstone for the PL reconstruction.

An anatomic PMTL reconstruction is described later in this chapter. In the majority of chronic unstable knees, the distal attachments of the PMTL are disrupted or replaced with scar tissue and it is necessary to perform a graft substitution of the PMTL. In select cases in which the distal attachments of the PMTL are intact, an advancement and recession of the popliteus tendon at the femoral attachment site may be performed, with repair of the PFL attachment tissues.

A nonanatomic femoral-fibular graft reconstruction is described as an option that is occasionally performed for acute or chronic ruptures of the PL structures. This procedure is indicated when the FCL is elongated or deficient and the PMTL does not require graft substitution. The operative procedure is advantageous when operative time is limited (as in dislocated multiligament knees) or when a relatively rapid stabilizing procedure is required. However, anatomic reconstruction and repair of disrupted PL structures are preferred, as previously described.

A third operative approach is described using a proximal advancement of the PL structures when chronic insufficiency of the PL structures exists from a minor injury (without complete traumatic ligament disruption). In knees with varus osseous malalignment and a varus thrust on ambulation, there is frequently an insufficiency of the PL structures due to chronic interstitial tearing. In these situations, a definitive FCL of normal width and integrity (although lax) may be identified at surgery and the PMTL attachments are intact though elongated. A graft reconstruction of the FCL and PMTL is not indicated in these knees. Instead, the PL structures may be advanced proximally in a more simplified operative procedure that avoids the added complexity and morbidity from major graft reconstructive procedures. The PL structures must be carefully inspected at surgery, because this procedure will fail if there is scar tissue replacement or if the distal attachments of the PL structures are disrupted.

Anatomic Reconstruction of the FCL and PMTL

FCL B-PT-B Reconstruction

The goal of an FCL reconstruction is to use a strong graft, attached by bone to anatomic insertion sites on the femur and fibula. This construct provides the cornerstone for the remainder of the PL repair and reconstruction. With an intact FCL resisting LJO and external tibial rotation, immediate protected knee motion may be initiated postoperatively to counteract the expected limitation of joint motion and scar tissue that occur after major ligament reconstructive procedures.

Graft Choices for FCL Reconstruction

The normal anatomic attachment sites of the FCL to the lateral femur and anterolateral aspect of the fibular head are carefully identified.²² A suture is placed between the two attachment sites and the length is measured to determine the required graft size. The bone portion of each end of the graft is 22 to 25 mm in length. The fibular graft attachment is performed using a tunnel at the anatomic attachment site. The femoral graft attachment is performed by placing a femoral tunnel at the anatomic attachment site. A second option is a femoral inlay of the proximal bone portion of the graft, which is useful if there is a 5- to 8-mm discrepancy of graft length that will not allow full coverage of the bone in a femoral tunnel.

Critical Points FIBULAR COLLATERAL LIGAMENT BONE–PATELLAR TENDON–BONE RECONSTRUCTION

• Anatomic FCL attachment sites to lateral femur, anterolateral aspect of fibular head identified.

• Femoral graft attached via tunnel at FCL anatomic site. Inlay procedure useful if 5–8 mm discrepancy of graft length that does not allow full coverage of bone portion of graft.

• Patellar tendon graft: ≥50 mm.

• B-PT-B allograft favored over soft tissue graft owing to prompt osseous incorporation and healing at femoral and fibular attachment sites.

• Placement of fibular and femoral tunnels

Anterior “bare area” of fibula exposed 20 mm, avoid lateral dissection that may injure CPN.

Fibular tunnel drilled using guide pin to depth of 25 mm.

Avoid drilling too deep.

Femoral tunnel placed eccentric to normal FCL attachment, allows collagen portion of graft to occupy normal FCL anatomic location.

• B-PT-B graft placement

Bone portion of graft gently taped into fibular tunnel, bone entirely seated into tunnel and level with proximal fibular head.

Ideal graft fixation: two small fragment cortical screws placed anterior-to-posterior engaging both fibular cortices, in proximal third and distal third bone portion of graft.

Proximal bone portion of graft placed in femoral tunnel.

Graft conditioned by cycling knee 20–30 times.

Graft fixed with soft tissue interference screw, 30° flexion, neutral tibial rotation, 22 N.

B-PT-B, bone–patellar tendon–bone; CPN, common peroneal nerve; FCL, fibular collateral ligament.

The patellar tendon graft must normally be 50 mm or longer to be suitable for an anatomic FCL reconstruction. The average cross-sectional area of the FCL reported by LaPrade and associates¹⁸ is 11.9 ± 2.9 mm². The FCL graft is 8 to 10 mm × 4 mm, resulting in a 32- to 40-mm² graft. If the patient’s own tissue is of sufficient length, an autograft harvested from the ipsilateral or contralateral patellar tendon provides the most ideal graft. In revision cases in which a prior FCL allograft reconstruction has failed, an autograft approach is favored. The hypothesis is that an autograft will heal at the fibular and femoral tunnels, with minimal remodeling and weakening of the graft in the postoperative phase. The complications of a meticulously performed B-PT-B graft harvest from the contralateral knee are less than 1% in terms of infection, scar formation, and graft site pain.³⁶

If an allograft is chosen, as is the usual case in multiligament reconstructions, a B-PT-B allograft is favored over a soft tissue graft owing to more prompt osseous incorporation and healing at femoral and fibular attachment sites. It is recognized that soft tissue allografts require added maturation time and may incompletely remodel even under the best of circumstances.^27,48 Alternative options include an AT-B or QT-PB graft. The bone portion may be placed at either the fibular or the femoral site.

Placement of Fibular and Femoral Tunnels

The attachment sites at the fibula and femur are identified. The anterior “bare area” of the fibula is exposed for 20 mm, avoiding lateral dissection that may injure the CPN. The fibular tunnel is drilled first, using a guide pin to a depth of 25 mm. The drills are gradually increased in diameter to create a final 9-mm tunnel (Fig. 22-13). Care should be taken to avoid drilling too deep, because the drill would break out the cortex distally at the fibular neck, close to the location of the CPN. The normal cortical integrity of the fibular head is not disrupted to maintain circumferential cortical fixation strength at the fibular attachment site.

FIGURE 22-13 Anatomic substitution of the FCL with a B-PT-B autograft or allograft shows two methods for fibular graft fixation. A, (Authors’ choice.) Two small fragment screws are used to fix the bone into a slot created in the proximal fibula. Interference screw fixation is used at the femoral anatomic site of the FCL. B, A fibular tunnel is made, the graft seated, and an interference screw is used for fixation. A backup suture post (not shown) may be required.

The femoral tunnel is placed 5 mm eccentric to the normal FCL attachment to allow the collagen portion of the graft to occupy the normal FCL anatomic location. A Beath guide pin is passed for the femoral tunnel, which is angulated in an anterior and proximal direction in line with the FCL fibers at 30° of knee flexion.

If an ACL reconstruction has been performed, it is necessary to diverge the FCL tunnel in an anterior direction away from the ACL tunnel to maintain integrity of the two tunnels. The edges of the femoral tunnel are smoothed with a rasp to avoid graft abrasion.

B-PT-B Graft Placement

The bone portion of the graft is gently taped into the fibular tunnel so that the bone is entirely seated into the tunnel and level with the proximal fibular head to preserve graft length. The bone portion of the graft is marked with ink to define the correct depth in the fibular tunnel. The ideal graft fixation is with two small-fragment cortical screws placed from anterior-to-posterior engaging both fibular cortices, in the proximal third and distal third of the bone portion of the graft (Fig. 22-14). The angle of the screw is posterior and never lateral in order to protect the CPN. The cortical screws may be 2.7 or 3.5 mm, based on the size of the graft and fibular head. A washer is used anteriorly. Alternative graft fixation methods include an interference screw and, rarely, sutures tied over the fibular cortex.

FIGURE 22-14 Postoperative AP (A) and lateral (B) radiographs of a 22-year-old man who underwent a PCL quadriceps tendon–patellar bone autograft tibial inlay two-strand reconstruction, an ACL B-PT-B allograft reconstruction, and a PL reconstruction. The FCL B-PT-B allograft fixation is shown. The method of fixation at the femur was a bone inlay at the anatomic FCL fixation site and at the fibula with two small fragment screws. An advancement of the popliteus tendon at the femur and repair of the PFL were also performed.

(A and B, Reprinted from Noyes, F. R.; Barber-Westin, S. D.: Posterolateral knee reconstruction with an anatomical bone–patellar tendon–bone reconstruction of the fibular collateral ligament. Am J Sports Med 35:259–273, 2007.)

The proximal bone of the graft is advanced into the femoral tunnel. The graft is conditioned by cycling the knee 20 to 30 times. The graft is fixed with a soft tissue interference screw at 30° knee flexion, in neutral tibial rotation, under an approximate 5-pound (22-N) tensile load on the sutures, which have been advanced by the Beath needle to the medial aspect of the knee joint. The graft is purposely not overtensioned to avoid overconstraining the lateral tibiofemoral joint.

PMTL Repair

At the time of the reconstructive procedure, the integrity of the PMTL is determined as previously described. In cases in which partial PMTL function exists and the joint’s external tibial rotation (PL subluxation) is deemed only moderate (10° increased tibial rotation at 30° of knee flexion), a femoral advancement may be performed without graft substitution. The distal attachment sites must be intact and the muscle tendon unit of relatively normal-appearing tissue and not replaced by scar tissue that would stretch out postoperatively.

In these partial injuries, disruption at the musculotendinous portion of the popliteus occurs acutely with subsequent healing and an elongated but intact structure. In these cases, an advancement of the popliteal tendon at its femoral attachment will restore tension in the entire structure. The tendon is incised at its attachment site, a tunnel of the same depth is drilled at the anatomic attachment, and the tendon is sutured with two nonabsorbable sutures and advanced into the tunnel by using a Beath needle.

The final fixation of the tendon in the tunnel is with a soft tissue interference screw. Rarely, additional graft fixation is required and the graft sutures tied to a post on the medial femoral cortex through a limited anteromedial incision where the Beath pin exits.

The associated FCL graft reconstruction provides the fixation necessary to protect the popliteal tendon advancement. Additional sutures are placed between the popliteus and the FCL reconstruction to restore the PFL. The purpose of the PFL repair is to add a passive attachment of the popliteal tendon to the fibula attachment, avoiding a second graft and a second fibular tunnel.

Graft Replacement of PMTL

The graft replacement of the PMTL is shown in Figure 22-15. An AT-B allograft is favored, with the bone portion of the graft placed at the anatomic femoral insertion site and the collagenous portion of the graft is passed in the tibial tunnel. Alternative grafts to consider are a B-PT-B allograft (which is more difficult to pass through the tibial tunnel) or a semitendinosus-gracilis (STG) two-strand autograft (which is less ideal because there is no bone attachment on the femur).

FIGURE 22-15 Anatomic popliteus muscle-tendon-ligament reconstruction and FCL reconstruction with B-PT-B autograft or allograft. A, Location of PL tibial tunnel and graft passage. A soft tissue interference screw and suture post are used for tibial fixation of the popliteus graft. B, Passage of popliteus graft beneath the FCL B-PT-B graft. C–E, Final fixation of the popliteus and FCL graft reconstructions.F and G, Suture of popliteus graft to posterior margin of the FCL graft at the fibular attachment site to restore the PFL. H and I, Suture plication of the PL capsule to posterior margin of the FCL graft.

An incision is made just beneath Gerdy’s tubercle, extending from the bare area of the anterior fibula to the tibial tubercle and then 3 cm distally along the anterolateral tibia. Careful subperiosteal dissection exposes the anterolateral aspect of the tibia in Gerdy’s safe zone, as already described.

A retractor is placed anterior to the lateral gastrocnemius muscle and tendon to expose the popliteus muscle. One mistake is to place the posterior tibial tunnel too proximal, because the tibia has a normal posterior convexity. A second mistake is to place the posterior tibial tunnel too far medially. A lateral placement of the tibial tunnel is required to increase the moment arm of the graft to resist external tibial rotation. Distal dissection over the popliteus muscle and distal placement of retractors is avoided as the anterior tibial artery courses laterally to enter the anterolateral compartment.

The final tibial 8-mm tunnel is at the most lateral aspect of the tibial margin and 15 mm distal to the joint line, passing through the popliteus muscle attachment and just medial to the tibiofibular joint. A guide pin is placed anterior-to-posterior and the correct position confirmed with the tunnel drilled protecting the posterior structures. The total length of the graft is determined from the femoral to tibial insertion, including added length for the tibial suture fixation distal to the anterior tibial tunnel.

The graft is passed through the femoral tunnel and then through the tibial tunnel and fixed at the femoral site by an interference screw. The graft is then conditioned by repetitive knee flexion and extension, and fixation is performed with an absorbable interference screw in the tibial tunnel with the leg at 30° of knee flexion, neutral tibial rotation, and approximately 5 pounds (22 N) of tension placed on the graft. A backup suture fixation post with a screw is used on the anterolateral aspect of the tibia.

A final assessment of the graft is done to determine that it is under adequate tension and is blocking abnormal external tibial rotation and knee hyperextension. With graft reconstructions of both the FCL and the PMT, it is not necessary to add additional drill holes to the fibula to perform a graft reconstruction of the PMTL. Rather, a direct suture of the PMT graft to the FCL graft at the level of the fibular head is performed (see Fig. 22-15F and G). A plication procedure is performed of the PLC at 10° of flexion, avoiding overtension, which would limit normal extension (see Fig. 22-15H and I).

PLC Graft Reconstruction for Severe Varus Recurvatum and Hyperextension

In patients who demonstrate 15° or more of knee hyperextension, severe deficiency exists of the entire posterior capsule and oblique popliteal ligament in addition to possible cruciate, FCL, and PMTL damage (Fig. 22-16). In these severe knee injuries, a PMTL reconstruction alone will not block a severe varus recurvatum deformity. A PLC reconstruction is required in addition to a reconstruction of the PMTL and FCL (Fig. 22-17). The operative approach and placement of the tibial tunnel for the capsular reconstruction using an AT-B allograft is the same as described for the PMT reconstruction. The only difference is that the bone portion of the graft is placed adjacent to the lateral gastrocnemius tendon (LGT) origin by a femoral tunnel or a bone inlay. The inlay technique is required when a concurrent ACL reconstruction is performed to avoid a second femoral tunnel. The fixation at the femoral attachment requires a portion of the LGT insertion (which is very broad) to be partially incised to expose the site for the AT-B graft fixation. The fixation of the bone inlay is by two small-fragment cancellous screws and washers (Fig. 22-18). This provides a stable bone-to-bone attachment. If a femoral tunnel is used, a 7-mm interference screw is selected. The graft lies along the PLC, which is plicated (vest-over-pants), and the graft is passed through the tibial tunnel.

FIGURE 22-16 A, A 20-year-old gymnast with chronic deficiency of the PL structures and complaints of recurrent hyperextension injuries with athletic activities. The ACL and PCL were intact, although a prior partial disruption could not be excluded. B, Dial test at 30° and 90° demonstrates increased tibial rotation of the right knee.

FIGURE 22-17 PL capsular reconstruction for severe knee hyperextension using an Achilles tendon allograft. A, Patient positioning. B, Identification of the peroneal nerve at fibular neck. C, Identification of FCL and popliteus muscle-tendon-ligament (PMTL), functionally intact. D, Exposure of the femoral graft site at lateral gastrocnemius tendon attachment. E, Placement of the tibial drill hole to the PL tibia, distal to the joint line. F, Placement of the PL femoral drill hole.G, Placement of the Achilles tendon allograft with bone plug at femoral site. H, Fixation at the femoral site and graft conditioning with tension of distal graft. I, Graft fixation at the tibia with interference screw and suture post. J, Cosmetic closure.

FIGURE 22-18 AP (A) and lateral (B) radiographs show fixation of PL capsular reconstruction with two 4.0-mm cancellous screws at the femoral site and an absorbable interference tibial screw and suture post. At the femoral site, either a bone inlay or a tunnel may be selected.

The tendon portion of the graft is fixated at the tibia after graft conditioning similar to that previously described for the PMTL reconstruction. The knee is placed at 10° of flexion with 5 pounds (22 N) of graft tension. The knee joint will passively go to 0°. Ultimately, the graft will stretch a few millimeters; the goal is to allow 0° to –2° of hyperextension, which effectively blocks knee hyperextension and varus recurvatum. Frequently, the ACL is ruptured and the two ligaments grafts (ACL and PLC graft) work in concert to block varus recurvatum. The same is true when a concomitant PCL reconstruction is performed.

In highly unstable knees that demonstrate severe disruption of all of the PL structures (and that have 15°–20° of hyperextension), it may be necessary to add both a PMTL and a PLC graft. Both grafts are brought out of the tibial tunnel that is drilled to 10 mm in diameter. Each graft is conditioned as previously described and then fixed by sutures to a single tibial post. A soft tissue interference screw is used at the tibial tunnel after graft suture post fixation.

Femoral-Fibular Reconstruction

The nonanatomic femoral-fibular graft reconstruction is indicated when the FCL is deficient, as already described. This technique is contraindicated when a combined PMTL graft reconstruction is required. In these knees, an anatomic FCL and PMTL reconstruction is performed.

The femoral-fibular reconstruction provides a large graft reconstruction of the FCL and a posterior graft arm to augment the PL structures. The PLC reconstruction is performed by a plication procedure. The popliteus tendon is plicated to the fibular FCL reconstruction to restore the PFL. The procedure is termed a nonanatomic reconstruction because the femoral-fibular graft is placed adjacent but not directly at the FCL femoral and fibular anatomic attachment sites.

The FCL femoral-fibular reconstruction does have several advantages. The graft placement (by drilling a tunnel anterior and posterior to the FCL femoral and fibular attachment sites) is relatively simple and allows a large doubled graft to be placed at the lateral side of the knee joint. Direct suture of the graft to itself provides lateral stability in acute operative repairs to initiate immediate protected knee motion postoperatively. The double-strand FCL graft provides a cornerstone for plication or repair of the other disrupted PL structures. In global chronic knee ligament reconstructions when considerable operative time is necessary, the femoral-fibular reconstruction has less operative time and complexity than anatomic reconstruction of the FCL and PMTL.

A femoral-fibular reconstruction has disadvantages. In cadaver studies, a femoral-fibular graft was found not to unload a concurrent PCL graft reconstruction in the same manner as a combined FCL and PMTL graft reconstruction.²⁹ In addition, although a single femoral-fibular graft stabilizes the knee at time zero, this graft may stretch out in the long term when there is loss of the PMTL, which does not participate in load sharing. Therefore, all the load is transferred to the single graft. The goal of PL reconstruction is to restore the function of all the PL structures and not just the femoral-fibular component. A modification of a femoral-fibular technique is to cross the graft, placing the anterior femoral portion to the posterior fibula to restore PFL function. However, whether this option is superior to two parallel femoral-fibular graft arms is not known.

A straight lateral incision, approximately 12 cm in length, is used centered over the lateral joint line. The surgical approach already described is followed. The incision is extended distally to allow exposure of the fibular head and peroneal nerve and proximally to allow exposure of the attachment of the FCL to the femur. The skin flaps are mobilized beneath the subcutaneous tissue and fascia to protect the vascular and neural supply to the skin. The attachment of the ITB is identified.

An inferior incision is made along the posterior aspect of the ITB and the attachments overlying the biceps muscle. This allows the ITB to be reflected anteriorly so that the anatomy of the PL aspect of the knee is easily visualized. A second anterior ITB incision may also be required.

The CPN is carefully protected throughout the surgical procedure for the drill hole made through the proximal fibula for placement of the FCL graft. It is usually not necessary to dissect the peroneal nerve when its course can be identified.

The fibular head is exposed anteriorly and posteriorly by subperiosteal dissection. Only 12 to 15 mm of the proximal fibula is exposed. A 6-mm drill hole is carefully made anteriorly and posteriorly in the center of the fibular head; a drill guide is used to ensure that soft tissues are protected. A straight curet is used to dilate the 6-mm cortical hole from anterior to posterior, compressing the cancellous bone. Care is taken not to disturb the tibiofibular joint capsule, thereby preserving joint stability.

At the femoral attachment of the FCL, a 6-mm drill hole is made anterior-to-posterior to the FCL insertion. The drill hole is deepened, leaving approximately 8 to 10 mm of cortex between the anterior and the posterior tunnels. This step requires care to preserve the lateral femoral cortex at the FCL attachment site. A curved curet is used to make a bony tunnel underneath the ligament insertion without removing excess bone, which would weaken the insertion site.

A tendon allograft or autograft, 6 to 8 mm in diameter, is prepared. The graft is measured to allow sufficient length (19–20 cm) for the anterior and posterior arms of the circle graft to overlap posteriorly, which provides additional collagenous tissue to the PL aspect of the joint (Fig. 22-19A and B). Two interlocking closed loop (baseball) sutures of No. 2 nonabsorbable suture are placed into both ends of the graft. The graft is initially stretched for 15 minutes under an 89-N load with a ligament-tensioning device. A four-strand STG autograft or comparable allograft may be used.

FIGURE 22-19 Femoral-fibular reconstruction. A and B, Placement of femoral and fibular tunnels and FCL graft. C and D, Suturing and tensioning of graft arms. E and F, Multiple sutures are used through both arms of the graft and the slack FCL. Plication of the PL capsule is performed to the graft.

An incision is made vertically just behind the FCL into the PLC. The tissues of the PLC, PMTL, and FCL are carefully inspected. The popliteus tendon is inspected from its insertion site to the muscle belly. If the PLC has excessive redundancy, then a simple capsular plication can be performed. The graft is inserted through bone tunnels in the femur and fibula, with the graft strands next to the stretched and slack FCL. The graft is placed under slight tension with the knee at 30° of flexion, neutral tibial rotation, and with the lateral side of the joint closed (after repair of meniscal attachments when necessary). It is important not to internally rotate the tibia during graft tensioning, which would result in an abnormal restraint of external rotation. Multiple interrupted sutures are used through the posterior overlapped arms of the graft (see Fig. 22-19C and D). The slack FCL is thus interposed between the anterior and the posterior arms of the circled graft, and horizontal sutures are placed between both structures (see Fig. 22-19E and F). Sutures are placed between the popliteus tendon at the musculotendinous junction to restore the attachment to the fibula (PFL). If the PMT is lax, the tendon may be shortened by direct repair or the tendon is advanced and recessed at its anatomic femoral attachment into a tunnel and fixated with an absorbable interference screw.

As an alternative procedure, the lax FCL is incised in its midportion and a repair of the overlapping ends performed with interrupted nonabsorbable sutures.

The knee is taken through a range of 0° to 90° of flexion, and normal internal-external rotation is ascertained at 30° of knee flexion to avoid overconstraining the joint. The PLC plication or advancement is then performed under sufficient tension to allow 0° of extension without hyperextension.

There are many different types of femoral-fibular reconstructions with modification of the two graft arms crossing as discussed or with a graft strand passing posteriorly from the femoral to posterior tibial attachment to reconstruct the PMTL. Clinical data are insufficient to recommend one procedure over another.

Proximal Advancement of the PL Structures

A straight lateral incision, approximately 12 cm in length, is used centered over the lateral joint line and dissection proceeds as already described. The incision extends distally to allow exposure of the fibular head and proximally to allow exposure of the attachment of the FCL to the femur. The skin flaps are mobilized beneath the subcutaneous tissue and fascia, protecting the vascular and neural supply. The attachment of the ITB is identified. An incision is made along the anterior border of the ITB and continued proximally, overlying the vastus lateralis. The attachment of the ITB to the lateral intramuscular septum is preserved.

The PL structures are carefully identified. A definitive FCL of normal width and integrity (although lax) is identified, and the PL structures are verified to have adequate thickness (and not replaced by scar tissue). An incision along the posterior border of the ITB and biceps muscle facilitates exploration of the PMTL as described. It is important to verify that the popliteus attachments to the fibula (PFL) and tibia are intact; otherwise, surgical restoration of the distal attachment site would be required. If a definitive normal-appearing FCL is not observed, or if there is scar tissue replacement of the PL structures, autograft or allograft reconstruction is required, as already described. The PL structures appear normal except for a mild to moderate increase in elongation.

The CPN is palpated and protected throughout the procedure and is not dissected from its anatomic position. The joint capsule of the knee is incised vertically 10 mm anterior to the popliteal tendon’s femoral attachment site. This permits the popliteal tendon attachment to be visualized on the lateral femoral condyle. A Kelly clamp is passed through this opening in the capsule and under the popliteus tendon, FCL, and anterior third of the lateral gastrocnemius muscle tendon attachment. An incision is made in the periosteum just superior and proximal to the attachment of the FCL to the femoral epicondyle. This incision is continued with a vertical, posterior arm into the anterior third of the LGT and anterior arm just anterior to the popliteus tendon attachment.

The new attachment site for the PL structures is prepared by elevating the periosteum proximal to the FCL over a distance of 15 mm. A curved osteotome is used to elevate an 8-mm-thick × 15-mm-wide wedge of bone at the attachment site of the PL structures, extending distally to the joint, avoiding the articular cartilage (Fig. 22-20A and B). Two Allis clamps are placed on the osteotomized bone. Any remaining soft tissue attachments are cut with a knife. The PLC attachment is incised posteriorly, avoiding the popliteus tendon (see Fig. 22-20C and D).

FIGURE 22-20 Proximal advancement of intact but lax PL structures. A and B, The PL structures are identified and have a normal, although lax, appearance. The line for the osteotomy of the femoral attachment of the FCL, PMT, popliteus muscle tendon and anterior portion of the gastrocnemius tendon is shown. C and D, The osteotomy is 8 mm deep to provide sufficient bone to maintain the attachments of the FCL, popliteus tendon, anterior gastrocnemius tendon, and PL capsule. The PL capsule is incised 15 mm in length.E and F, The bone attachment of the PL structures is advanced proximally in line with the FCL, with the knee in neutral tibial rotation and 30° flexion. Reattachment of the bone is achieved with a four-pronged staple and screw.

The proximal attachment site is dissected subperiosteally, contoured with an osteotome, and a sufficient amount of bone removed to allow the osteotomized bone attachment inlay to be placed and the staple to not be prominent. It is necessary to ensure that the popliteus tendon is well attached to the anterior portion of the osteotomized bone so that it will be taut when tension is applied. The bone attachment site of the PL structures is advanced in the proximal direction of the FCL with the knee in 30° of flexion and neutral tibial rotation. The 90° flexion position is not recommended because this produces an anterior and distal attachment of the PL structures that induces large forces with knee flexion-extension and risks stretching out the PL structures.

The goal is to advance the FCL in a proximal direction to remove excessive slackness and to use staple fixation at the normal anatomic site. The bone attachment site may be slightly rotated to adjust the tension in the posterior capsular tissues to avoid overconstraining knee extension. The advanced bone attachment is fixed with a medium four-prong staple (see Fig. 22-20E and F). The distal margin of the staple is placed directly at the anatomic site of attachment of the FCL to restore normal FCL length. A cancellous bone screw is used for additional fixation.

The function of the FCL is determined after fixation to ensure that there is only 2 to 3 mm of LJO on varus stress testing and no abnormal external tibial rotation or hyperextension. The PL tissues are tensioned to allow the knee to come to 5° of flexion and to resist further extension after this point, gradually reaching 0° to –2° hyperextension during the postoperative rehabilitation period. The ITB tension is determined. A distal advancement of the ITB at the tibial attachment may be required to restore normal tension in this structure. The ITB is closed anteriorly and posteriorly with absorbable sutures. In order to prevent lateral tethering on the patella, the ITB and lateral patellar retinaculum are loosely closed or not closed. The proximal advancement procedure is often combined with other operative procedures when the more complicated anatomic PL reconstruction is not required (Fig. 22-21).

FIGURE 22-21 A 38-year-old female physician with symptomatic chronic ACL rupture referred to the authors’ center after failure of ITB tenodesis. An acute SMCL repair at the index procedure was successful. A, Grade III pivot shift. A harvest of a semitendinosus-gracilis (STG) graft was performed (not shown) through the prior medial incision. B, Identification of failed ITB tenodesis with deficient anterolateral structures. C, Outside-in femoral tunnel at the anterior cruciate ligament (ACL) anatomic site on lateral wall of femur. D, Harvest of ITB for extra-articular (EA) reconstruction due to severe anterior instability. E, Osteotomy and advancement of PL structures that were intact but lax, allowing abnormal increased lateral joint opening and external tibial rotation at 30° flexion. F, Internal fixation of proximal advancement and extra-articular reconstruction. The ITB graft was looped under one of the staple prongs and sutured to itself and the remaining ITB to provide a secondary restraint. The remaining ITB was closed. This procedure was successful in restoring posterolateral and anterior stability.

Anatomic PL Reconstruction

A consecutive group of knees that had an anatomic PL reconstruction including an FCL B-PT-B reconstruction were prospectively followed 2 to 13.7 years postoperatively.³⁵ All major PL structures were surgically restored as required. The procedure represented a primary reconstruction in 7 patients and a revision in 6 patients. ACL ruptures were found in 7 patients and bicruciate ruptures in 5 patients, all of which were reconstructed.

At follow-up, 13 of the 14 (93%) PL reconstructions restored normal or nearly normal LJO and external tibial rotation (Fig. 22-22). The ACL reconstructions were normal or nearly normal in 11 knees and abnormal in 1 knee. All patients achieved at least 0° to 135° of knee motion; 1 required a gentle manipulation, and 1 had an arthroscopic lysis of adhesions to achieve this range of knee motion.

FIGURE 22-22 Lateral stress radiographs of a 22-year-old man 2 years after a combined FCL B-PT-B autogenous reconstruction, an ACL B-PT-B allograft reconstruction, and a PCL two-strand quadriceps tendon–patellar bone reconstruction. There is no measurable difference in the millimeters of lateral tibiofemoral joint opening between the reconstructed (A) and the opposite (B) knee.

(A and B, Reprinted from Noyes, F. R.; Barber-Westin, S. D.: Posterolateral knee reconstruction with an anatomical bone–patellar tendon–bone reconstruction of the fibular collateral ligament. Am J Sports Med 35:259–273, 2007.)

Critical Points AUTHORS’ CLINICAL STUDIES: ANATOMIC FIBULAR COLLATERAL LIGAMENT RECONSTRUCTION WITH A BONE–PATELLAR TENDON–BONE GRAFT

• N = 14 followed 2–13.7 yr postoperative.

• ACL reconstructed in 7 knees, ACL and PCL reconstructed in 5 knees

• Evaluation: comprehensive knee examination, lateral stress x-ray, KT-2000, 20°, 134 N, IKDC, Cincinnati Knee Rating System.

• Results

93% normal/nearly normal lateral tibiofemoral joint opening and external tibial rotation.

All knees at least 0°–135°.

Significant improvements pain, swelling, patient rating, walking, stair-climbing.

11 patients returned to low-impact sports without problems.

ACL, anterior cruciate ligament; IKDC, International Knee Documentation Committee; PCL, posterior cruciate ligament.

Significant improvements were found at follow-up for pain (P = .0001), swelling (P = .02), patient rating of the overall knee condition (P < .001), walking (P < .05), and stair-climbing (P < .05). Before the operation, 9 of the 12 patients had moderate or severe pain with daily activities, but at follow-up, only 1 patient had such pain. Eleven of the 12 patients had given up sports activities completely before the operation, and 1 was participating in low-impact activities without problems. At follow-up, 11 patients were participating in mostly low-impact athletics (swimming, bicycling) without symptoms and 1 patient was participating in sports that involved pivoting and cutting with pain and limitations against advice.

The results of the anatomic PL reconstructions were similar for primary and revision cases. The only failure occurred in a revision knee. A total of 17 PL procedures had been performed in the 6 revision knees before the anatomic reconstruction. The failed PL procedures included nonanatomic graft augmentation procedures, primary repairs in knees with chronic PL ruptures, or biceps tendon procedures. None of these knees had surgical restoration of all of the PL structures in one setting. In addition, none of the revision knees had a successful ACL procedure and, therefore, all required ACL reconstruction or revision during the anatomic PL graft reconstruction.

Femoral-Fibular Allograft Reconstruction

Two investigations were performed on the femoral-fibular allograft reconstruction for chronic instability.³⁷ The first study followed 20 consecutive patients from 2 to 7.8 years postoperatively. Lateral stress radiographs and a comprehensive knee examination showed that 16 knees (76%) had a functional FCL and PL reconstruction and 5 failed. All knees but 1 had at least 0° to 135° of knee motion at follow-up, and no patient required an additional operation for a limitation of motion.

Critical Points AUTHORS’ CLINICAL STUDIES: FIBULAR COLLATERAL LIGAMENT FEMORAL-FIBULAR ALLOGRAFT RECONSTRUCTION

• N = 27 followed mean 12.7 yr (range, 2–19 yr).

• Evaluation: comprehensive knee examination, lateral stress x-ray, KT-2000, 20°, 134 N, IKDC, Cincinnati Knee Rating System.

• Results

64% normal/nearly normal lateral tibiofemoral joint opening and external tibial rotation.

All knees at least 0°–135°.

Significant improvements pain, swelling, giving-way, walking, stair-climbing.

63% returned to low-impact sports without problems.

IKDC, International Knee Documentation Committee.

Significant improvements were found for symptoms and functional limitations (P < .01). Before the operation, 9 patients had moderate pain with activities of daily living, 7 had pain with any sports activities, and 4 had no pain with light sports but had pain with moderate sports (running, twisting, turning activities). At follow-up, 2 patients had pain with daily activities, 2 had pain with any sports activity, and 16 could participate in mostly light sports without pain.

A longer-term follow-up of the femoral-fibular reconstruction was conducted in a group of 27 patients. In 10 patients, the reconstruction failed before the minimum 2-year follow-up period. These cases were included in the overall failure rate, but not in the subjective and functional analyses. Five of these patients had undergone prior unsuccessful PL procedures before the femoral-fibular reconstruction. In 6 of these patients, a revision of the FCL and PL structures was performed, and in 2 patients with chronic pain, a total knee replacement was done. In 1 patient, the allograft was removed, and in 1 patient, no further operative procedure had been done at the time of writing.

The remaining 17 patients were evaluated a mean of 15 years (range, 4–19 yr) postoperatively. Statistically significant improvements were found in the scores for pain, swelling, giving-way, walking, stair-climbing, running, and twisting (P < .05). Before the operation, 50% of the patients had moderate to severe pain with daily activities, but at follow-up, only 13% had these complaints. Before the operation, all patients either had given up all athletic activities or had severe limitations with even light recreational activities. At follow-up, 63% were participating in low-impact activities such as swimming and bicycling without problems, 6% were participating with symptoms, and 31% were not participating in athletic activities. In these 17 patients, the FCL reconstructions were rated as normal or nearly normal (IKDC ratings, LJO and external tibial rotation) in all knees. Twelve patients had required a concomitant ACL reconstruction that were rated as normal or nearly normal in 8 and abnormal in 4.

Because of the increased failure rate, which was attributed to including patients with poor PL tissues and prior failed PL procedures, the authors now recommend anatomic PL reconstruction. A femoral-fibular procedure is used only in chronic knees in which the PMTL is functional and the goal is to augment a deficient FCL. This operation is also useful in acute PL disruptions to restore FCL function, along with a primary repair of the remaining PL tissues.

Proximal Advancement of PL Structures

A proximal advancement of the PL structures was done in conjunction with a cruciate ligament reconstruction in 23 consecutive patients.³⁸ One patient was lost to follow-up. A second patient had an early failure and required a revision PL reconstruction; this result was included in the study’s overall failure rate.

Therefore, 21 patients made up the study group and were evaluated 2 to 6.1 years postoperatively. The ACL was also reconstructed in 9 knees, the PCL was reconstructed in 11 knees, and both cruciates were reconstructed in 1 knee.

At follow-up, 20 knees (91%) had normal or nearly normal LJO and external tibial rotation, and 2 (9%) failed. At least 0° to 135° of knee motion was found in 16 patients. Two patients had mild limitations (between 1° and 5°) in both extension and flexion, 1 patient had a mild limitation of extension only, and 2 patients had mild limitations in flexion only. No further operations were performed for losses of knee motion.

Before the operation, 8 patients had pain with daily activities, 8 had pain with any sports activity, and 5 could participate in light sports but had pain with moderate sports (running, twisting, turning activities). At follow-up, 2 patients had pain with daily activities, 9 patients had pain with any sports activity, and 10 were able to participate in low-impact sports without pain. Overall, 71% of patients showed improvement in the pain score or had no symptoms with light sports.

Before the operation, all patients either had given up sports activities or were participating with symptoms and functional limitations. At follow-up, 62% had returned to mostly low-impact activities without symptoms. The other patients did not return owing to their knee condition. At the time of the operation, 52% of the patients had abnormal articular cartilage lesions (grade 2A, 2B, or 3A > 15 mm, CKRS).

Critical Points AUTHORS’ CLINICAL STUDIES: PROXIMAL ADVANCEMENT POSTEROLATERAL STRUCTURES

• N = 21 followed 2–6.1 yr.

• ACL reconstructed in 8 knees, PCL reconstructed in 10 knees, ACL and PCL reconstructed in 4 knees.

• Evaluation: comprehensive knee examination, lateral stress x-ray, KT-2000, 20°, 134 N, IKDC, Cincinnati Knee Rating System.

• Results

91% normal/nearly normal lateral tibiofemoral joint opening, external tibial rotation.

ACL normal/nearly normal in 92%.

62% patients returned to low-impact sports without problems.

ACL, anterior cruciate ligament; IKDC, International Knee Documentation Committee; PCL, posterior cruciate ligament.

This study shows the advantage of this operation in properly selected patients who have interstitial stretching of the PL structures without prior traumatic disruption, allowing advancement to restore normal tension.

Causes of Failure of PL Operative Procedures

The potential causes of failure of 57 operative procedures (30 index and 27 revisions) to the PL structures of the knee were studied in a consecutive series of 30 knees that were referred to the authors’ center.³⁹ The index PL procedures were done for an acute knee injury in 13 knees (mean, 3 wk; range, 1–11 wk after the injury) and for chronic deficiency in 17 knees a mean of 56 months (range, 4–312 mo) after the original injury.

The review of medical records in all cases was done by an independent surgeon not involved in the care of the patients. Upon the initial evaluation, a comprehensive knee examination and lateral stress radiographs were performed. KT-2000 testing was done in knees with ACL ruptures, and posterior stress radiographs were done in knees with PCL ruptures.

Overall, for all 57 failed PL operations, nonanatomic graft procedures had been done in 23 knees (77%; Table 22-3). The definition of an anatomic reconstruction was a graft placed in anatomic ligament attachment sites with secure internal fixation. Therefore, suture repairs, extra-articular ITB augmentations, and biceps tendon rerouting methods (Fig. 22-23) were not considered anatomic procedures.

FIGURE 22-23 A patient with a failed biceps femoris tenodesis for PL instability was unable to actively rotate the left tibia externally. This procedure is not recommended.

Untreated varus malalignment was identified in 21 failed PL procedures (37%) or in 10 of 30 knees (Tables 22-4 and 22-5). Patients who presented with PL deficiency and varus osseous malalignment were diagnosed with triple varus knees. Associated ACL, PCL, or bicruciate deficiency was identified in 27 knees (93%). ACL deficiency was identified in 41 of the 57 (72%) failed PL procedures and associated PCL deficiency was noted in 15 of the 57 (26%) failed PL procedures.

Critical Points AUTHORS’ CLINICAL STUDIES: CAUSES OF FAILURE OF POSTEROLATERAL OPERATIVE PROCEDURES

• N = 57 failed PL procedures in 30 knees.

• Evaluation: review of medical records by an independent surgeon, comprehensive knee examination, lateral stress x-ray, KT-2000, 20°, 134 N, PCL stress x-ray, IKDC, Cincinnati Knee Rating System.

• Causes of PL failure

93% associated cruciate deficiency (either untreated or failed reconstruction).

77% nonanatomic PL procedures (suture repair, iliotibial band augmentations, biceps tendon rerouting).

37% untreated varus osseous malalignment (triple varus knee).

• Conclusions

Emphasis during index operation on anatomic PL reconstruction, concurrent reconstruction all torn cruciate ligaments.

If varus osseous malalignment exists, correct with osteotomy before PL reconstruction.

IKDC, International Knee Documentation Committee; PL, posterolateral.

PL deficiency subjects ACL and PCL grafts to excessive tensile loading owing to the abnormal lateral tibiofemoral joint opening that occurs with activity. Several in vitro studies reported significantly increased forces on ACL and PCL grafts in knees with sectioned PL structures (see Chapter 20, Function of the Posterior Cruciate Ligament and Posterolateral Structures), providing further evidence of the deleterious effects of FCL and PMTL insufficiency after ACL or PCL reconstruction.

Limitations of this study were similar to those of other investigations in which the potential causes of ligament reconstruction failure were defined. It is difficult to determine in a retrospective manner the exact causes of failure. Several theoretical factors exist that cannot always be detected or measured. These include failure of grafts to fully remodel or heal, poor tissue quality due to extensive disruption to the popliteus and FCL, limited healing potential of soft tissues due to repeated operations and diminished blood supply, osteopenic bone preventing appropriate fixation, and gait hyperextension abnormalities that may have occurred postoperatively without the knowledge of the investigators.

In addition, because the study period extended over 2 decades, the evolution of the diagnosis and management of PL injuries and associated abnormalities has altered the treatment of these problems. Some of the procedures in this series represent operations that are no longer routinely performed. Even so, the results of this study suggest greater emphasis during the index operation for anatomic graft reconstruction of one or more of the PL structures as necessary, restoration of all ruptured cruciate ligaments, and correction of varus malalignment. The authors have long advocated anatomic PL reconstruction over suture repair in patients who sustain acute high-energy injuries and extensive disruption of the PL structures. Usually, at least one component of the PL structures requires graft reconstruction, which is the FCL in nearly all cases.