Meniscal Transplantation

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CHAPTER 8 Meniscal Transplantation

Nicole A. Friel, Mark A. Slabaugh, Brian J. Cole

Surgical treatment of meniscus lesions has changed significantly over time. Meniscal tears were traditionally treated with meniscal excision, but it became understood that loss of the meniscus alters the biologic and biomechanical environment of the knee.1,2 The resulting degenerative changes in the involved compartment led us away from meniscus removal and toward meniscus preservation. Partial meniscectomy and meniscus repair procedures have become the standard of care. For patients for whom meniscal preservation is not an option, meniscal allograft transplantation can be done for a select subset of patients who have become symptomatic from their meniscal deficiency. This offers restoration of anatomic and biomechanical function.

With the advent of meniscal transplantation procedures, several techniques have evolved, including separate bone plugs on the anterior and posterior horns as well as bone bridges (keyhole, trough, dovetail, and bridge in slot variations). The bone bridge is almost always used for the lateral meniscus because of the close proximity between the anterior and posterior horns. The medial meniscus can be anchored with either plugs or a bridge, because the anatomy of the anterior horn is variable and the plugs may allow for minor modifications. We prefer the bridge in slot technique for lateral and medial menisci for a number of reasons, including its simplicity and secure bony fixation, ability to perform concomitant procedures easily, and the ability to maintain the native anterior and posterior meniscal horn attachments.

ANATOMY

The menisci are semilunar-shaped fibrocartilaginous structures that function in shock absorption,3 load transmission,4–6 secondary mechanical stability,7,8 joint lubrication,9 and nutrition.10 Circumferentially oriented collagen fibers provide resistance to hoop stresses whereas radially oriented fibers hold the circumferential fibers together and provide resistance to shear.11,12 The anterior and posterior horns attach to bone by interdigitating collagen fibers oriented to transmit load and shear optimally from the meniscus to the tibia.13

The menisci are composed of 74% water,14 allowing for optimization in force transmission. The lateral meniscus carries 70% of the lateral compartment load, compared with 50% by the medial meniscus.6,15 The menisci transmit 50% of the joint load when in knee extension and 90% when the knee is in flexion.6,15 Loss of the meniscus, therefore, increases the load on the articular cartilage surfaces and facilitates the development of early degenerative changes. Loss of just 16% to 35% of the meniscal tissue can lead to a 350% increase in contact forces.4 Clinical studies support meniscus preservation, because a greater size of meniscal resection is associated with a poor clinical outcome.16–19

PATIENT EVALUATION

History

Eliciting a thorough history is especially important because causative factors, associated injuries, and prior treatments can all affect the treatment plan. Often, patients report a specific knee injury with subsequent surgical treatment consisting of meniscectomy or meniscal repair. Patients usually describe a period of pain relief following the surgery but, over time, joint line pain and activity-related swelling ensue. Recent operative reports or photographs are useful to rule out arthritic changes, which would otherwise contraindicate meniscal transplantation. In a setting in which recent information is unavailable regarding the anatomy and pathology in the knee (e.g., from a recent arthroscopy), it might be prudent to consider a diagnostic arthroscopy to provide updated information for proper surgical planning.

Physical Examination

Examination often reveals full range of motion. Depending on recent activity, a joint effusion may be present. Joint line or femoral condyle tenderness is occasionally found. A thorough physical examination is essential to reveal malalignment, ligament deficiency, or articular cartilage lesions that would modify the treatment plan. These findings need to be addressed, either as a concurrent or staged procedure.

Diagnostic Imaging

A complete set of radiographs must be obtained to evaluate limb alignment and the degree of joint space narrowing and secondary osteoarthritic changes caused by a prior meniscectomy. In addition, a magnification marker or quarter should be placed on the cassette at the level of the joint line on two orthogonal views for meniscal sizing. Views include weight-bearing anteroposterior (AP) in full extension, weight-bearing posteroanterior (PA) in 45-degree-flexion, non–weight-bearing 45-degree-flexion, axial view of the patellofemoral joint, and a long leg mechanical axis view.

Magnetic resonance imaging (MRI) is usually reserved for challenging cases when certain questions are left unanswered. The extent of meniscectomy, status of the articular cartilage, and degree of subchondral edema in the involved compartment can all be assessed by MRI.

TREATMENT

Indications and Contraindications

The success of meniscal transplantation depends on careful selection of the ideal candidate. Typically, patients are relatively young (younger than 50 years) and often present with a history of prior total or subtotal meniscectomy with persistent pain localized to the meniscus-deficient compartment. The knee joint must be stable or stabilized and have normal alignment, with intact articular surfaces (grade I or II). Any grade III or IV lesions should be focal and require concomitant treatment.

Although not absolute contraindications, chondral defects, malalignment, or ligamentous instability all require consideration for concurrent or staged procedures to ensure that all joint pathology is addressed. In the past, full-thickness chondral defects were considered a contraindication; however, cartilage degeneration is not a significant risk factor for meniscal allograft failure.20 Outcomes of many concurrent procedures, including meniscal transplantation with concurrent autologous chondrocyte implantation (ACI)21,22 and osteochondral allograft32 have shown excellent results in the carefully selected patient.

Concurrent or staged corrective osteotomy is indicated for patients with deviation toward the involved compartment. Axial malalignment can exert abnormal pressure on the newly placed graft, which can lead to loosening, overload, degeneration, and failure.23–25

Anterior cruciate ligament (ACL)–deficient patients who have had a prior medial meniscectomy may benefit from concomitant ACL reconstruction (ACLR) and meniscal transplantation. Many studies have shown that meniscectomized ACL-deficient knees lead to worsening degenerative changes. The more aggressive approach of combination ACLR and meniscal transplantation has good long-term follow-up as opposed to untreated (left alone) knees. In addition, the posterior horn of the medial meniscus is an important secondary stabilizer to anterior translation and may be important in preventing secondary “stretch” of the ACL reconstructed knee.7,26–28

Contraindications for meniscal transplantation include diffuse arthritic changes, squaring or flattening of the femoral condyle or tibial plateau, significant osteophyte formation in the involved compartment, tibiofemoral subluxation, inflammatory arthritis, synovial disease, previous joint infection, skeletal immaturity, or marked obesity.

Conservative Management

Patients who have had a prior meniscectomy should have a trial of conservative treatment before consideration of operative measures. Activity modifications, anti-inflammatory medications, and occasionally injections can be recommended to help determine which patients can function without surgical intervention. More aggressive management of the relatively young patient following lateral meniscectomy might be considered, especially in female athletes with slight valgus who are at significant risk for the development of progressive lateral compartment arthritis.29

PEARLS& PITFALLS

• Patient selection for operative intervention is crucial. Patients must be able to understand the indications, activity limitations, and possible outcomes.
• Patients who are overweight or have unrealistic expectations regarding excessive postoperative function need to realize that the longevity of the meniscal graft is negatively affected by these two variables.

Arthroscopic Technique

Preoperative Planning

Allograft Sizing.

The success of meniscal transplantation is dependent on careful size matching of the meniscus allograft to the native meniscus. Meniscal allografts are compartment- and size-specific. Anteroposterior and lateral preoperative radiographs with sizing markers are important for meniscal sizing (Figs. 8-1 and 8-2). Allograft sizing is of significant importance, because oversized meniscal allografts lead to greater forces across the articular cartilage.30 On the other hand, undersized allografts result in greater forces seen by the meniscal tissue.30 The meniscus width is determined on the AP radiograph by measuring from the edge of the ipsilateral tibial spine to the edge of the tibial plateau. Meniscal length is determined on the lateral radiograph as determined by the AP dimension of the ipsilateral tibial plateau. These measurements, after correction for magnification, are multiplied by 0.8 for medial and 0.7 for lateral meniscus. Other methods using height and weight have been proposed, but are not routinely used.31,32

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FIGURE 8-1 Preoperative AP radiograph, weight bearing. Note the slight medial compartment narrowing and sclerosis of the subchondral tibial plateau.

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FIGURE 8-2 Preoperative lateral radiograph in flexion with sizing markers anteriorly, which allow the meniscus to be sized properly.

Meniscal Graft Processing and Preservation.

Meniscal allografts are harvested using sterile surgical technique ideally within 24 hours after death and frozen to −80° C. Although other graft preservation methods are used, including secondary sterilization methods, fresh-frozen grafts remain the most commonly used allograft preservation method.33–35

Stringent donor selection is based on comprehensive medical and social history. The risk of disease transmission is further reduced by screening for human immunodeficiency virus (HIV), human T-cell lymphotropic virus (HTLV), hepatitis B and C, and syphilis. Blood cultures for aerobic and anaerobic bacteria, as well as lymph node sampling, may be performed. Graft processing, including débridement, ultrasonic-pulsatile washing, and use of ethanol to denature proteins, further lowers the risk of disease transmission.36

PEARLS& PITFALLS

• Be aware of the techniques used to sterilize the meniscal allograft; different companies use different proprietary sterilization techniques.
• Sizing of the meniscal allograft based on radiographs should be confirmed with the company representative prior to the day of surgery. The day of surgery is too late to find out that the graft is too small or large.

Anesthesia

Meniscal transplantation can be performed under regional, spinal, or general anesthesia based on surgeon and anesthesia preferences. Patient age, comorbidities, and adverse events with previous anesthesia are important in the decision-making process.

Positioning

The patient is positioned supine on a standard operating room table. A tourniquet is placed around the thigh, and the extremity is placed in a standard leg holder, allowing full knee flexion. It is important that the posterolateral or posteromedial corner be freely accessible for inside-out suturing of the meniscus.

Surgical Anatomy, Incisions, and Portals

Important surgical landmarks to be identified are the patella, patellar tendon, tibial plateau, and fibular head. Portals and incisions include inferomedial and inferolateral arthroscopy portals, an accessory outflow portal, a posterolateral or posteromedial incision, and a miniarthrotomy adjacent to or splitting the patellar tendon on the transplant side (Fig. 8-3).

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FIGURE 8-3 Intraoperative photograph of a left knee showing the lateral incisions in preparation for a lateral meniscal transplantation. The oblique mark shows the path of the iliotibial band. The head of the fibula is marked as well.

Caution should be taken while making incisions because many structures are at risk, depending on the approach. These include the peroneal nerve and lateral collateral ligament with the posterolateral approach, the saphenous nerve and medial collateral ligament with the posteromedial approach, and the patellar tendon with the anterior miniarthrotomy. In addition, the posterior neurovascular bundle can be damaged during needle passage when suturing the meniscus in place, especially on the lateral side.

Examination Under Anesthesia and Diagnostic Arthroscopy

Examination under anesthesia evaluates range of motion and ligamentous instability. Diagnostic arthroscopy is completed to confirm the preoperative diagnosis and evaluate any changes in articular cartilage.

PEARLS& PITFALLS

• Diagnostic arthroscopy should confirm any arthrosis in the affected compartment; grade I or II cartilage damage is acceptable at the time of meniscal transplantation.
• Grade IV chondral damage should be treated with concomitant allografting of the femoral condyle.

Arthroscopic Preparation.

Initially, the steps for medical and lateral meniscal transplantation are similar. The remaining meniscus is arthroscopically débrided to a 1- to 2-mm peripheral rim until punctate bleeding occurs (Fig. 8-4). The most anterior part of the meniscus can be excised with an no. 11 scalpel through the respective anterior portal. The anterior and posterior horn insertion sites should be maintained, because they are helpful markers during preparation of the slot. In addition, limited notchplasty along the posterior and inferior femoral condyle allows for improved visualization of the posterior horn during passage of the graft.

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FIGURE 8-4 Intraoperative depiction of the anterior horn and body of a medial meniscus débridement in preparation for meniscal transplantation.

PEARLS& PITFALLS

• Resection of the femoral condyle at the notch can be performed to improve visualization for medial or lateral meniscal transplantation.
• Resection of the anterior horn is accomplished with a no. 11 blade or back biter.
• A no. 15 blade can also be used to resect the anterior meniscus because no. 11 blade tips often break if too much torque is placed on the knife.

Exposure.

A miniarthrotomy is preformed directly adjacent to or through the patellar tendon on the affected side, in line with the patellar tendon fibers. To allow correct orientation of the slot and introduction of the graft, the arthrotomy is performed in line with the insertion sites of the anterior and posterior horns of the involved meniscus. Prior localization with a spinal needle to determine the proper trajectory is helpful to ensure proper incision location. The incision should extend approximately one-third above the joint line and two thirds below the joint line.

For lateral meniscal transplantations, a second posterolateral incision is made at the interval between the posterior edge of the iliotibial band and the anterior edge of the biceps femoris tendon. The gastrocnemius muscle-tendon junction is elevated off the posterior capsule at the joint line, and the meniscal retractor is placed anterior to the muscle. Proper retraction allows suture tying beneath these structures to minimize the chances of soft tissue tethering with flexion or extension.

For medial meniscal transplants, a second posteromedial incision is made, just anterior to the hamstrings tendons. The sartorial fascia is incised and the hamstrings tendons are retracted posteriorly. The interval is opened between the posteromedial aspect of the capsule just anterior to the gastrocnemius and semitendinosus tendons. Proper retraction facilitates retrieval and suturing of meniscal sutures.

PEARLS& PITFALLS

• Localization with a spinal needle helps determine the patellar incision and the proper trajectory of the meniscal bone slot.
• Incision should be at the joint line; an incision too inferior or superior will make it difficult to achieve the proper angles in subsequent steps.

Slot Preparaztion.

Slot orientation follows the normal anatomy of the meniscal attachment sites. Electrocautery is used to establish a line connecting the center of the anterior and posterior horn attachment sites. Using this line as a guide, a 4-mm burr is used to make a straight anterior to posterior reference slot in the tibial plateau (Fig. 8-5). Slot height and width will equal the dimensions of the burr, and its alignment in the sagittal plane should parallel the slope on the tibial plateau. Slot measurements, including the AP length of the tibial plateau, are confirmed by placement of a depth gauge in the reference slot (Fig. 8-6). A drill guide is used to place a guide pin just distal and parallel to the reference slot (Figs. 8-7 and 8-8). The drill guide is advanced to but not through the posterior cortex. The pin is subsequently overreamed with a 7- or 8-mm cannulated drill bit (Fig. 8-9). A box cutter osteotome is then used to widen the trough to 7 to 8 mm and deepen it to 10 mm (Fig. 8-10). This is then refined with a 7- to 8-mm rasp to allow insertion of the bone bridge of the allograft. Final slot preparation is shown in Figure 8-11.

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FIGURE 8-5 Intraoperative depiction of a 4-mm burr directly in line with the anterior and posterior horn of the medial meniscus. The burr will make a preliminary slot for measuring and placing the guide pin.

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FIGURE 8-6 Intraoperative depiction of the depth gauge and guide pin placement.

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FIGURE 8-7 Intraoperative depiction of the burr slot with the guide pin inserted. Partial reaming has been performed to ensure that the trajectory and depth are appropriate prior to finishing reaming to the posterior cortex.

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FIGURE 8-8 Schematic representation of a guide pin positioned in the superficial tibial plateau reference slot.

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FIGURE 8-9 Schematic of a cannulated drill bit used to create the tibial tunnel over the pin placed through the guide just distal and parallel to the slot created by the burr.

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FIGURE 8-10 Schematic representation of the box cutter, which is impacted over the guide pin into the tibial tunnel to create a slot 7 to 8 mm wide all the way to the posterior cortex.

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FIGURE 8-11 Intraoperative depiction of final slot preparation. The slot is 8 mm wide and extends to the posterior cortex.

PEARLS& PITFALLS

• Place the initial guide pin with the knee in flexion and do not penetrate the posterior cortex. Consider fluoroscopic guidance.
• Ensure that the box-cutting osteotome is in line with the prior burr cut.
• Use a curette to clear remaining bone from the slot.
• During initial burring for slot preparation in a medial meniscal transplantation, be aware of and avoid the ACL insertion. Approximately 25% of its insertion can be violated before concerns of instability arise.
• Do not violate the posterior cortex when reaming.

Meniscal Allograft Preparation.

The meniscus allograft tissue arrives as a hemiplateau with an attached meniscus. All nonmeniscal soft tissue is removed. Attachment sites of the meniscus are identified on the bone block, and the accessory attachments are débrided, leaving only true attachment sites (approximately 5 to 6 mm wide). The meniscus is then prepared to achieve the desired width and length, as determined by the slot preparation. The width of the bone bridge is intentionally undersized by 1 mm to facilitate graft passage into the slot and reduce inadvertent bridge fracture during placement. The bone bridge is then cut to a width of 7 mm and a height of 10 mm. Bone extending beyond the posterior horn attachment is removed so that the posterior wall of the bone bridge will be flush with the most posterior edge of the prepared slot. Bone extending to the anterior horn, however, should be preserved to maintain graft integrity and ease in graft insertion. A vertical mattress traction suture (0 polydioxanone [PDS]) is placed at the junction of the posterior horn and middle thirds of the meniscus (Fig. 8-12).

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FIGURE 8-12 Final graft preparation shows that the meniscal horn attachment sites have been preserved and the bone bridge easily fits into an 8-mm slot. Also note the PDS suture at the posterior third junction of the meniscus.

If the anterior horn attachment is larger (up to 9 mm wide), the attachment should be left intact and the width of the bone bridge should be increased accordingly in the area of the anterior horn insertion only. The remainder of the bone bridge should be the intended 7 mm. To accommodate the increased width, the corresponding area of the recipient slot should be widened.

PEARLS& PITFALLS

• All soft tissue should be removed from the meniscal graft and bone block to help with visualization during insertion.
• The word “TOP” is written on the superior portion of the meniscus to ensure that the graft has not flipped or rotated during insertion.
• Care must be taken to not damage the meniscal insertion sites when cutting the bone block.
• The bone block should be the same depth as the trough created to avoid a prominent bone block that needs to be burred down after insertion.

Meniscus Insertion and Fixation.

Using a single-barrel, zone-specific meniscal repair cannula placed through the contralateral portal, a Nitinol suture-passing pin is placed through the capsule at the attachment site of the posterior middle third of the meniscus. The proximal end of the Nitinol pin is withdrawn from the anterior arthrotomy site, the allograft traction sutures are passed through the loop of the Nitinol pin, and the pin and traction sutures are withdrawn through the accessory incision. With the aid of the traction sutures, the meniscal allograft is pulled through into the joint through the anterior arthrotomy while the bone bridge is advanced into the tibial slot. The meniscus is manually reduced under the condyle with a finger placed through the arthrotomy. Appropriate varus or valgus stress is needed to open the ipsilateral compartment as well as flexion-extension aids in graft introduction and reduction.

Once the meniscus is reduced, the knee is cycled to ensure proper placement and capturing by the tibiofemoral articulation. A guidewire is inserted between the bone bridge and the medial eminence side of the slot. A tap is inserted over the guidewire to create a path for the interference screw, with the bone bridge held in place manually (typically, a freer; Fig. 8-13). The bone bridge is then secured within the tibial slot with a 7 × 25-mm bioabsorbable cortical interference screw. This step is typically done in flexion under direct visualization.

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FIGURE 8-13 Intraoperative depiction of the slot completely filled with the bone bridge. This is held in place with a freer and fixed with an interference screw

Finally, the graft is attached to the capsule with eight to ten standard inside-out vertical mattress sutures (2-0 Ethibond) placed equally on the superior and inferior meniscal surfaces (Figs. 8-14 and 8-15). Sutures should be placed peripherally on the meniscus, because sutures placed in the middle or inner third of the meniscus can weaken the implant. For medial transplants, this fixation can be modified with the use of appropriate all-inside fixation devices placed most posteriorly and outside-in sutures placed most anteriorly.

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FIGURE 8-14 Intraoperative depiction of inside-outside meniscal repair. Note the vertical mattress orientation of the sutures. Sutures are placed alternatively on the inferior and superior surfaces.

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FIGURE 8-15 Intraoperative depiction of inside-outside meniscal repair of the transplant. A meniscal retractor is used to deflect the needles away from the posterior knee and out of the incision.

PEARLS& PITFALLS

• If the slot is off slightly medially or laterally to the desired position, it is possible to realign the bone trough by placing the interference screw on the opposite side.
• Varus or valgus stress can open up the compartment to facilitate meniscal passage into the appropriate position.
• Meniscal stitches are started at the site of the traction sutures and placed sequentially anteriorly and posteriorly to ensure correct tension.
• At least 10 sutures are needed to secure the meniscus circumferentially.
• Too much pressure on the bone block during insertion can cause it to break. If this occurs, transosseous sutures are placed through the posterior and anterior bone blocks and passed through a drill whole made in the posterior and anterior central aspect of the tibial slot, facilitated by using an ACL guide. The sutures are retrieved from outside-in using a suture passer and tied over the anterior cortex to secure the two fragments of bone block.

Closure.

Standard closure of the arthrotomy and accessory portal incisions is performed.

Concurrent Procedures

Anterior Cruciate Ligament and Medial Meniscal Transplantation.

In case of a concurrent ACL reconstruction, a soft tissue graft (hamstring autograft, Achilles allograft, tibialis anterior allograft, or hamstring allograft) is recommended, because this allows for a smaller diameter tibial tunnel. The ACL tibial tunnel is drilled as obliquely as possible, entering the medial aspect of the tibial footprint. Then, the femoral tunnel is drilled. Following tunnel placement, the meniscal slot should be prepared, as described earlier. Graft placement occurs in a sequential order—femoral fixation is completed first, followed by meniscal transplantation, and lastly tibial fixation of the ACL graft. The meniscus is secured with an interference screw between the ACL and the most lateral aspect of the bridge. Tibial ACL fixation as the final step allows maximum separation of the tibiofemoral joint during meniscal transplantation.

PEARLS& PITFALLS

• Drill the tibial tunnel first before making the trough for the meniscal transplantation.
• Soft tissue graft is preferred to make passing the graft easier with a meniscal transplant in place.
• Notch the bone bridge at the site of ACL tibial tunnel to reduce intersection pressure of the ACL graft against the bone bridge.
• With inadequate fixation from an interference screw, consider placing two transosseous sutures through the bone block anteriorly and posteriorly as described when the block inadvertently fractures during preparation or insertion. Remove a small segment of bone between the two bone blocks to accommodate the ACL as it courses from the tibia to the femur.

High Tibial Osteotomy and Medial Meniscal Transplantation.

All aspects of the meniscal transplantation are performed first. Varus or valgus stresses are needed to place the meniscus graft and, if not completed first, could jeopardize fixation of the osteotomy. The open wedge osteotomy is performed as distally as possible, with the osteotomy wedge passing at least 1.5 cm below the bottom of the tibial slot.

PEARLS& PITFALLS

• Two Steinmann pins can be placed above the osteotomy site but below the slot to prevent propagation of the osteotomy into the slot.

Cartilage Restoration and Meniscal Transplantation.

If ACI or osteochondral allografting is performed simultaneously, it is usually safer and easier to perform all steps of the meniscal transplantation and then proceed to the cartilage restoration procedure. Care should be taken, however, to avoid damage to the anterior horn of the transplanted meniscus with the arthrotomy and while placing osteochondral grafts.

PEARLS& PITFALLS

• Perform meniscal transplantation prior to the cartilage procedure. All the meniscal sutures except the anterior horn can be placed as noted above. The anterior horn can be stitched through the anterior arthrotomy at the end.
• Avoid damage to the meniscus graft by flexing the knee and using a retractor while performing the cartilage procedure.

Postoperative Rehabilitation Protocol

Immediate partial weight-bearing is allowed in a hinged knee brace, with range of motion limited to 0 to 60 degrees of flexion for the first 2 weeks and to 90 degrees at 4 weeks. Non–weight-bearing flexion beyond 90 degrees is also allowed immediately. Progression to full weight bearing and range of motion as well as strengthening exercises are achieved at 4 weeks postoperatively. Squatting and pivoting are avoided until 16 weeks, at which in-line running is permitted. Return to full activity is permitted after 6 months as long as strength is 80% that of the contralateral leg.

CONCLUSIONS

Meniscal allograft transplantation yields good to excellent results in almost 85% of patients (Table 8-1). Patients demonstrate significant decrease in pain, as well as an increase in activity. Long-term success is encouraging in well-selected patients but it is unknown whether meniscal transplantation is protective against the progression of degenerative changes.

TABLE 8-1 Results of Meniscal Allograft Transplantation.

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REFERENCES

1. Allen PR, Denham RA, Swan AV. Late degenerative changes after meniscectomy. Factors affecting the knee after operation. J Bone Joint Surg Br. 1984;66:666-671.

2. Baratz ME, Fu FH, Mengato R. Meniscal tears: the effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. A preliminary report. Am J Sports Med. 1986;14:270-275.

3. Voloshin AS, Wosk J. Shock absorption of meniscectomized and painful knees: a comparative in vivo study. J Biomed Eng. 1983;5:157-161.

4. Seedhom BB, Hargreaves DJ. Transmission of load in the knee joint with special reference to the role of the menisci: part II. Experimental results, discussions, and conclusions. Eng Med Biol. 1979;8:220-228.

5. Seedhom BB, Dowson D, Wright V. Proceedings: functions of the menisci. A preliminary study. Ann Rheum Dis. 1974;33:111.

6. Walker PS, Erkman MJ. The role of the menisci in force transmission across the knee. Clin Orthop Relat Res. 1975;(109):184-192.

7. Levy IM, Torzilli PA, Warren RF. The effect of medial meniscectomy on anterior-posterior motion of the knee. J Bone Joint Surg Am. 1982;64:883-888.

8. Markolf KL, Mensch JS, Amstutz HC. Stiffness and laxity of the knee—the contributions of the supporting structures. A quantitative in vitro study. J Bone Joint Surg Am. 1976;58:583-594.

9. MacConaill MA. The movements of bones and joints; the synovial fluid and its assistants. J Bone Joint Surg Br. 1950;32:244-252.

10. Renstrom P, Johnson RJ. Anatomy and biomechanics of the menisci. Clin Sports Med. 1990;9:523-538.

11. Bullough PG, Munuera L, Murphy J, et al. The strength of the menisci of the knee as it relates to their fine structure. J Bone Joint Surg Br. 1970;52:564-567.

12. McDevitt CA, Webber RJ. The ultrastructure and biochemistry of meniscal cartilage. Clin Orthop Relat Res. 1990;(252):8-18.

13. Gao J, Wei X, Messner K. Healing of the anterior attachment of the rabbit meniscus to bone. Clin Orthop Relat Res. 1998;(348):246-258.

14. Cole BJ, Carter TR, Rodeo SA. Allograft meniscal transplantation:: background, techniques, and results. Instr Course Lect. 2003;52:383-396.

15. Ahmed AM, Burke DL. In-vitro measurement of static pressure distribution in synovial joints. Part I: tibial surface of the knee. J Biomech Eng. 1983;105:216-225.

16. Bonneux I, Vandekerckhove B. Arthroscopic partial lateral meniscectomy long-term results in athletes. Acta Orthop Belg. 2002;68:356-361.

17. Higuchi H, Kimura M, Shirakura K, et al. Factors affecting long-term results after arthroscopic partial meniscectomy. Clin Orthop Relat Res. 2000;(377):161-168.

18. Meredith DS, Losina E, Mahomed NN, et al. Factors predicting functional and radiographic outcomes after arthroscopic partial meniscectomy: a review of the literature. Arthroscopy. 2005;21:211-223.

19. Rockborn P, Gillquist J. Outcome of arthroscopic meniscectomy. A 13-year physical and radiographic follow-up of 43 patients under 23 years of age. Acta Orthop Scand. 1995;66:113-117.

20. Stone KR, Walgenbach AW, Turek TJ, et al. Meniscus allograft survival in patients with moderate to severe unicompartmental arthritis: a 2- to 7-year follow-up. Arthroscopy. 2006;22:469-478.

21. Farr J, Rawal A, Marberry KM. Concomitant meniscal allograft transplantation and autologous chondrocyte implantation: minimum 2-year follow-up. Am J Sports Med. 2007;35:1459-1466.

22. Rue JP, Yanke AB, Busam ML, et al. Prospective evaluation of concurrent meniscus transplantation and articular cartilage repair: minimum 2-year follow-up. Am J Sports Med. 2008;36:1770-1778.

23. Cameron JC, Saha S. Meniscal allograft transplantation for unicompartmental arthritis of the knee. Clin Orthop Relat Res. 1997;(337):164-171.

24. de Boer HH, Koudstaal J. Failed meniscus transplantation. A report of three cases. Clin Orthop Relat Res. 1994;(306):155-162.

25. Noyes FR, Barber-Westin SD, Rankin M. Meniscal transplantation in symptomatic patients less than fifty years old. J Bone Joint Surg Am. 2005;87(suppl 1):149-165.

26. Alford W, Cole BJ. Failed ACL reconstruction and meniscus deficiency. Background, indications and techniques for revision ACL reconstruction with allograft meniscus transplantation. Sports Med Arthrosc Rev. 2005;13:93-102.

27. Shelbourne KD, Gray T. Results of anterior cruciate ligament reconstruction based on meniscus and articular cartilage status at the time of surgery. Five- to fifteen-year evaluations. Am J Sports Med. 2000;28:446-452.

28. Shoemaker SC, Markolf KL. The role of the meniscus in the anterior-posterior stability of the loaded anterior cruciate-deficient knee. Effects of partial versus total excision. J Bone Joint Surg Am. 1986;68:71-79.

29. Alford JW, Lewis P, Kang RW, et al. Rapid progression of chondral disease in the lateral compartment of the knee following meniscectomy. Arthroscopy. 2005;21:1505-1509.

30. Dienst M, Greis PE, Ellis BJ, et al. Effect of lateral meniscal allograft sizing on contact mechanics of the lateral tibial plateau: an experimental study in human cadaveric knee joints. Am J Sports Med. 2007;35:34-42.

31. Stone KR, Freyer A, Turek T, et al. Meniscal sizing based on gender, height, and weight. Arthroscopy. 2007;23:503-508.

32. Van Thiel G, Verma NN, McNickle AG, et al. Meniscal allograft size can be predicted by height, weight and gender. Arthroscopy. 2009;25:722-727.

33. Alford W, Cole BJ. The indications and technique for meniscal transplant. Orthop Clin North Am. 2005;36:469-484.

34. McNickle AG, Wang VM, Shewman EF, et al. Performance of a sterile meniscal allograft in an ovine model. Clin Orthop Relat Res. 2009;467:1868-1876.

35. Rodeo SA. Meniscal allografts—where do we stand. Am J Sports Med. 2001;29:246-261.

36. Vangsness CTJr, Garcia IA, Mills CR, et al. Allograft transplantation in the knee: tissue regulation, procurement, processing, and sterilization. Am J Sports Med. 2003;31:474-481.

37. von Lewinski G, Milachowski KA, Weismeier K, et al. Twenty-year results of combined meniscal allograft transplantation, anterior cruciate ligament reconstruction and advancement of the medial collateral ligament. Knee Surg Sports Traumatol Arthrosc. 2007;15:1072-1082.

38. Hommen JP, Applegate GR, Del Pizzo W. Meniscus allograft transplantation: ten-year results of cryopreserved allografts. Arthroscopy. 2007;23:388-393.

39. Kim JM, Bin SI. Meniscal allograft transplantation after total meniscectomy of torn discoid lateral meniscus. Arthroscopy. 2006;22:1344-1350.

40. Sekiya JK, Ellingson CI. Meniscal allograft transplantation. J Am Acad Orthop Surg. 2006;14:164-174.

41. Verdonk PC, Verstraete KL, Almqvist KF, et al. Meniscal allograft transplantation: long-term clinical results with radiological and magnetic resonance imaging correlations. Knee Surg Sports Traumatol Arthrosc. 2006;14:694-706.

42. Cole BJ, Dennis MG, Lee SJ, et al. Prospective evaluation of allograft meniscus transplantation: a minimum 2-year follow-up. Am J Sports Med. 2006;34:919-927.

43. Verdonk PC, Demurie A, Almqvist KF, et al. Transplantation of viable meniscal allograft. Survivorship analysis and clinical outcome of one hundred cases. J Bone Joint Surg Am. 2005;87:715-724.

44. Graf KWJr, Sekiya JK, Wojtys EM, et al. Long-term results after combined medial meniscal allograft transplantation and anterior cruciate ligament reconstruction: minimum 8.5-year follow-up study. Arthroscopy. 2004;20:129-140.

45. Sekiya JK, Giffin JR, Irrgang JJ, et al. Clinical outcomes after combined meniscal allograft transplantation and anterior cruciate ligament reconstruction. Am J Sports Med. 2003;31:896-906.

46. Yoldas EA, Sekiya JK, Irrgang JJ, et al. Arthroscopically assisted meniscal allograft transplantation with and without combined anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2003;11:173-182.

47. Van Arkel ER, de Boer HH. Human meniscal transplantation. Preliminary results at 2- to 5-year follow-up. J Bone Joint Surg Br. 1995;77:589-595.

48. Ryu RK, Dunbar VWH, Morse GG. Meniscal allograft replacement: a 1-year to 6-year experience. Arthroscopy. 2002;18:989-994.

49. Wirth CJ, Peters G, Milachowski KA, et al. Long-term results of meniscal allograft transplantation. Am J Sports Med. 2002;30:174-181.

50. Rath E, Richmond JC, Yassir W, et al. Meniscal allograft transplantation. Two- to eight-year results. Am J Sports Med. 2001;29:410-414.

51. Stollsteimer GT, Shelton WR, Dukes A, et al. Meniscal allograft transplantation: a 1- to 5-year follow-up of 22 patients. Arthroscopy. 2000;16:343-347.

52. Garrett JC. Meniscal transplantation: a review of 43 cases with two- to seven-year follow-up. Sports Med Arthrosc Rev. 1993;2:163-167.

53. Van Arkel ER, de Boer HH. Survival analysis of human meniscal transplantations. J Bone Joint Surg Br. 2002;84:227-231.

SUGGESTED READINGS

Packer JD, Rodeo SA. Meniscal allograft transplantation. Clin Sports Med. 2009;28:259-283.

Verma NN, Kolb E, Cole BJ, et al. The effects of medial meniscal transplantation techniques on intra-articular contact pressures. J Knee Surg. 2008;21:20-26.

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