Arthroscopic Labral Repair

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CHAPTER 14 Arthroscopic Labral Repair

Carlos A. Guanche

Introduction

Our understanding of hip labral pathology as a cause of hip pain is evolving, and the various treatment interventions available are also in flux. The exact prevalence of acetabular labral tears in the general population is unknown. However, when investigating the incidence of these injuries among athletes who present with groin pain, a clinical assessment of 18 patients who presented to a sports clinic with complaints of groin pain and an age range of 17 to 48 years revealed that, in 4 of the 18 athletes (22%), a labral tear was documented with the use of magnetic resonance arthrography. On the basis of this analysis, it appears that an acetabular labral tear is certainly not uncommon and that treatment algorithms need to be delineated.

The current indications for labral repairs are somewhat variable. Although the labral tear as a result of a single traumatic event is the clearest indication for repair, this is a rare entity in clinical practice. More often, the inciting event is not obvious and chronic repetitive injuries leading to attritional tears are at fault, whereas in other cases femoroacetabular impingement or other bony variants may be at fault. It is important to realize not only that the labral tear should be treated but also that the underlying problems need to be addressed, or else the long-term outcomes will be poor.

Basic science

The hip labrum is a fibrocartilaginous structure that surrounds the rim of the acetabulum in a nearly circumferential manner. It is contiguous with the transverse acetabular ligament across the acetabular notch inferomedially. The labrum is widest in the anterior half and thickest in the superior half, and it merges with the articular hyaline cartilage of the acetabulum through a transition zone of 1 mm to 2 mm. It is attached to the edge of the bony acetabulum via a thin tongue of bone that extends into the tissue via a zone of calcified cartilage, and it adheres directly to the outer surface of this bony extension without a zone of calcified cartilage. A group of three or four vessels are located in the substance of the labrum on the capsular side of this extension. The structure is separated from the hip capsule by a narrow synovial-lined recess, which is variable in size. In general, the vascular supply of the adult hip labrum is poor, and regional differences in vascularity exist. Kelly and colleagues used cadaveric injection studies to define the vascularity of this area, and they demonstrated that the capsular portion of the labrum is significantly more vascular than the articular side, with only the peripheral third of the labrum having nutrient vessels. Extrapolating from our understanding of the healing capacity of the meniscus, repair strategies should be considered for tears that involve only the peripheral labrum.

The labrum functions to enhance the stability of the hip by maintaining the negative intra-articular pressure within the joint as well as by increasing congruity. With the use of a poroelastic finite element model, it has been determined that the labrum functions to provide structural resistance to the lateral motion of the femoral head within the acetabulum. Furthermore, it has been demonstrated that the labrum also functions to decrease contact pressures within the hip and to decrease cartilage surface consolidation. This effect is a result of maintaining the articular fluid in contact with the weight-bearing cartilage via a joint-sealing effect.

Indications

• Mechanical symptoms with rotational activities

• Unremitting pain in the groin with weight-bearing activities

• Concomitant femoroacetabular impingement with healthy, repairable tissue

• Traumatic dislocation or subluxation with ongoing mechanical symptoms

• Subluxation episodes in high-performance athletes

• Tissue with obvious vascularity in the proper (capsular) anatomic zone

• Tear of larger than 1 cm

Diagnosis of labral tears of the hip

The clinical presentation of patients with a tear of the labrum is variable, and, as a result, the diagnosis is often missed initially. Burnett and colleagues reported about a series of 66 patients in whom the diagnosis of a labral tear had been made by arthroscopy. In this series, the mean time from the onset of symptoms to diagnosis was 21 months. An average of 3.3 health care providers had seen each patient before the diagnosis of a labral tear was made. Groin pain was the most common complaint (92%), with the onset of symptoms most often being insidious. A positive “impingement sign” occurred in 95% of patients in this series; this sign consists of groin pain with flexion, adduction, and internal rotation of the symptomatic hip (Figure 14-1). Therefore, in young, active patients who present with complaints of groin pain, with or without a history of trauma, the diagnosis of a labral tear of the hip should be suspected and investigated further.

Figure 14–1 Physical examination of a patient with a hip labral tear. The maneuver of hip flexion, adduction, and internal rotation (called the impingement sign in some descriptions) should elicit frank mechanical catching and a reproduction of the pain associated with a labral tear.

Imaging and diagnostic studies

Standard radiographs (weight-bearing anteroposterior pelvis and frog-leg lateral) are critical as part of the initial assessment to evaluate the patient for arthritis and femoroacetabular impingement and also for more subtle dysplasias. Multiple studies have demonstrated the superior accuracy of magnetic resonance arthrography (MRA) as compared with standard magnetic resonance imaging for the diagnosis of labral tears. Intra-articular gadolinium has been shown to improve the sensitivity of diagnosing labral pathology from 25% to 92% with the use of a small field of view. Therefore, when clinical suspicion of a hip labral tear exists, MRA with a small field of view is the study of choice.

An intra-articular lidocaine injection is useful for situations in which the diagnosis of labral pathology is equivocal or in which a tear has been diagnosed by MRA but it is uncertain whether symptoms are related to this finding. Similar to its use for diagnosing external impingement of the shoulder, if patients experience relief from symptoms after the injection, the diagnosis of pain as a result of hip intra-articular pathology is more certain. Although this does not confirm that the labral tear is the problem, it certainly makes the case that intra-articular pathology is at least somewhat responsible for the symptomatology.

Surgical technique

The decision to proceed with operative intervention should be heavily weighed with regard to refractory mechanical symptoms. The majority of labral tears are treated with debridement; however, some tears are amenable to arthroscopic repair. Because the blood supply to the labrum enters from the adjacent joint capsule, peripheral tears have healing potential, and repairs should be considered if this pattern is encountered.

Technique for Arthroscopic Labral Debridement

The procedure can be performed with the patient in either the supine or lateral position, depending on the level of comfort of the surgeon. The procedure should employ both a 30-degree and a 70-degree arthroscope for a thorough assessment of both the labrum and associated pathology. Modified arthroscopic flexible instruments, extended shavers, and hip-specific instrumentation should be available to improve access to all areas of the hip joint. In addition, the positioning of instruments should be done in the proper portals, with consideration for the anatomic structures near the hip joint (Figure 14-2).

Figure 14–2 The standard arthroscopic portals employed for access to the hip joint (in this case, the left hip) with the patient in the supine position. The accessory mid-anterolateral portal is useful as a result of its appropriate angle of approach to the acetabular bone. A, Anterior portal; AAL, accessory anterolateral portal; AL, anterolateral portal; ASIS, anterosuperior iliac spine; PL, posterolateral portal; MAL, mid-anterolateral portal.

A diagnostic arthroscopic examination of the central compartment can be performed systematically to evaluate not only the labrum from anterior to posterior but also to locate possible cartilage lesions on both the acetabular and femoral sides. In addition, the integrity of the ligamentum teres should be assessed; this area can be a source of pain as a result of impingement of the soft tissues between the femoral head and the acetabulum. Any loose bodies should be noted and their source identified. Finally, an assessment should be made of any obvious capsular redundancy or laxity.

Many patients will have a significant synovitis associated with the labral tearing, and an effort should be made to resect some of the inflamed tissue to improve visualization of the joint and to decrease the associated pain. This should be undertaken with a radiofrequency probe to decrease the potential for bleeding and the subsequent compromise of the surgical field.

The goal of the surgical procedure should be to preserve as much native tissue as is technically feasible while resecting the degenerative or damaged material. This is important to maintain the labrum’s role as a secondary joint stabilizer and to minimize the potential for arthrosis. Frayed tissue should be debrided with the use of either motorized shavers or radiofrequency probes. It is important to delineate the areas of abnormal tissue that are identified both on radiographs (in the form of perilabral calcifications) and with magnetic resonance imaging or MRA (abnormal signal intensity) to thoroughly address the labral pathology.

Adjacent cartilage damage should be searched for and thoroughly addressed. Superficial lesions can be gently debrided with mechanical shavers and perhaps stabilized with the use of radiofrequency probes. Grade IV Outerbridge lesions should be managed with a thorough debridement down to a bleeding bed and by preparation with microfracture awls (Figure 14-3).

Figure 14–3 Chondroplasty of an articular cartilage lesion. A, Chondroplasty awl used for the preparation of significant chondral injuries of the acetabular and femoral cartilage. B, Final area of preparation with an obvious bleeding bed.

Technique for Arthroscopic Labral Repair

The decision to perform a labral repair is still a process in its infancy. The current indications include tears that are symptomatic and that have either obvious vascularity within their substance or are repairable to the acetabular bony wall or the adjacent capsule. In general, a tear that is less than 1 cm in length does not require repair because there is minimal associated instability and mechanical symptomatology. In addition, the decision to perform a repair should be predicated on having the appropriate instrumentation and adequate technical ability.

The arthroscopic techniques include the use of routine anterior and anterolateral portals as well as an accessory mid-anterior portal that is halfway between the two portals and about 2 cm distal (see Figure 14-2). The routine use of several accessory portals is supported by the fact that the anterior anatomy allows for safe portal establishment anywhere between the standard anterior portal and the posterolateral portal.

As described previously, the surgical procedure includes a diagnostic arthroscopy with the treatment of any associated pathology. In addition, most labral tears that are repaired will also require at least a partial debridement of the avascular and often degenerative tissue. After the completion of the debridement, preparation is made for the repair. Similar to the concept of arthroscopic labral repair in the shoulder, the use of suture anchors has been shown to be effective for fixation for those cases in which a bony detachment exists. In situations in which the tear is in the labrocapsular junction, the repair can be performed with the use of suture material that is placed around the labrum and repaired to the adjacent capsular tissue.

When the labral tear involves a detachment from the acetabulum either as a result of trauma or attritional tearing, a suture anchor is required for the stabilization of the tear. The area of the tearing is abraded and prepared with the use of either an aggressive shaver or a small burr. Fibrinous tissue is typically present at the bone–labrum interface, and an attempt is made to prepare the bed with a healthy vascular supply (Figure 14-4). The position of the anchor is critical to reestablishing the normal anatomy of the labrum. It should be placed on the acetabular rim to achieve an appropriate angle of approach while not penetrating into the articular cartilage. Avoiding chondral injury both in the head (upon delivery of the anchor) and with respect to acetabular penetration is important, because it can become a factor in joint degeneration. Both endoscopic and fluoroscopic visualization are essential (Figure 14-5). Options for repair include traditional suture anchors, which include knot tying or, more recently, the use of knotless anchors that allow for relatively easier technical maneuvers within the tight confines of the hip joint (Figure 14-6).

Figure 14–4 A, Labral tear in a left hip, viewed from the anterolateral portal. Note the frayed and devitalized tissue. B, Prepared bony bed in preparation for anchor delivery.

Figure 14–5 Arthroscopic and endoscopic visualization of suture anchor insertion. A, Endoscopic view of suture anchor cannula before anchor delivery. This is a right hip viewed from the anterolateral portal. The metal anchor delivery cannula is placed in the anterior portal, and it rests on the anterior acetabular wall. B, Fluoroscopic image of the cannula with its angle of approach diverging from the articular margin.

Figure 14–6 Knotless anchor technique. A, The insertion of the knotless anchor in the superior acetabulum (PushLock anchor [Arthrex, Inc., Naples, FL]). B, Final anchor position with suture well away from the articular margin.

After the anchor is placed, a suture-passing device should be employed for the penetration of the labrum. A variety of devices exist for this purpose, with some employing shuttle devices and some simply penetrating through the tissue (Figure 14-7). Most of the instruments have been adapted from shoulder arthroscopy instrumentation. When the suture anchor is in place and the sutures have been passed, standard knot-tying techniques are employed (Figure 14-8).

Figure 14–7 Suture penetrator in place within the substance of a labrum that is detached from the acetabular bony wall.

Figure 14–8 Labral repair with the use of a suture anchor with penetrator devices. A, Anchor in place. B, Final repair.

For cases in which an intrasubstance split is to be addressed, the cleavage plane in the labrum should be fully defined and debrided of all nonviable tissue. A suture shuttle device can be used to deliver a looped monofilament suture between the junction of the articular cartilage and the fibrocartilage labrum. A suture penetrator is then employed through the capsule to grasp the loop of monofilament. The looped suture is then used to shuttle a monofilament suture around the labral tearing and through the capsule. At this point, the suture is tied in an extra-articular position with the use of tactile feel and an automatic suture cutter (Figure 14-9).

Figure 14–9 Repair of a labrum with extracapsular suture positioning.

Rehabilitation after debridement

Technical Pearls

• Ensure that proper equipment is available, including longer instruments for anchor placement.

• Ensure the proper orientation of suture anchor insertion by confirming the insertion angle both endoscopically and fluoroscopically.

• Address the primary problem that caused the tear (i.e., look for impingement).

• Use repair strategies that maximize the healing potential.

• Prepare a bony bed.

• Attempt to approximate the labrum to the capsule to increase the vascular supply.

• Use accessory portals for anchor insertion if the available portals do not allow for an appropriate angle of insertion.

Formal therapy for range of motion and strengthening of the operative hip is begun 7 to 10 days after surgery. Weight bearing after an isolated arthroscopic labral debridement should be unrestricted, with the use of crutches limited to the early postoperative period only (i.e., 3 to 5 days). The standard protocol includes a gradual progression from increasing the range of motion to unrestricted strengthening. Aggressive hip flexor strengthening should be limited until full range of motion is obtained and until hip mechanics are relatively normal. For cases in which abnormal mechanics substitute the psoas or the hip flexors abnormally, a refractory tendonitis can develop. Explosive and rotational activities should be limited for at least 6 weeks. The return to unrestricted activity is predicated on a full, painless range of motion and the normal strength of the pelvic, abdominal, and lower-extremity musculature.

Rehabilitation after labral repair

Formal therapy for range of motion and strengthening of the operative hip should begin by 7 to 10 days postoperatively. Early range of motion is initiated to limit the scarring in the joint associated with the surgical trauma. Weight bearing after an isolated arthroscopic labral repair should be restricted to toe touching with the use of crutches for the first 4 weeks. The most important principle is to limit the rotational stresses that the repaired labrum experiences during the first few weeks. The ranges that put the repair at risk include flexion past 90 degrees, abduction past 25 degrees, and internal or external rotation limited to 25 degrees. Limitations are placed on flexion past 90 degrees for 10 days, whereas abduction and adduction are limited to 25 degrees for 4 weeks. Beginning at 4 weeks, a gradual progression from increasing the range of motion to unrestricted strengthening is begun. The use of stationary bicycling is encouraged and instituted during the first 10 days. Aggressive hip flexor strengthening should be limited until full range of motion is obtained and hip mechanics have normalized. For cases in which abnormal mechanics substitute the psoas or the hip flexors abnormally, a significant tendonitis can develop. Explosive and rotational activities should also be limited for at least 12 weeks. The return to unrestricted activity is predicated on a full, painless range of motion and the normal strength of the pelvic, abdominal, and lower-extremity musculature; this typically occurs approximately 4 to 6 months postoperatively.

Results

There are numerous studies that detail the use of arthroscopy for treating lesions of the hip labrum. However, collective interpretation is confounded by the nonuniform use of outcome measures and a lack of validated outcomes for nonarthritic hip pain. Further complicating the matter is the fact that many published series contain heterogeneous study populations in which subjects have associated hip pathology (e.g., arthritis, dysplasia, femoroacetabular impingement) in addition to labral tearing.

To date, there are no published series about the long-term outcomes of the arthroscopic repair of hip labral tears. Indications for the lesions that are considered to be repairable are currently evolving. Recently, Hines and colleagues presented outcome results with a mean follow up of 9 months for a series of 52 patients who underwent arthroscopic hip labral repair. Another study by Ross, which looked at the results of 19 patients, has also recently been published. The results of these studies and of those that have documented the outcomes of labral debridements are summarized in Table 14-1.

Table 14–1 Summary of Studies of the Results of Arthroscopic Debridement and the Repair of Tears of the Hip Labrum

Complications

Hip arthroscopy has been shown to be relatively safe in several studies that have documented its effectiveness as well as the number of resulting complications. In one large series, there was a 1.6% complication rate, with problems that included transient palsy of either the sciatic or the femoral nerve, paresthesias as a result of lateral femoral cutaneous nerve palsy, perineal injury, and instrument breakage.

Although this study was not specific to the repair of the hip labrum, specific problems are certainly associated with this procedure. As a result of the tight confines and the multiple instruments that are inserted into the joint, the possibility of serious articular cartilage damage exists. Care should be taken while working within the joint to ensure that cartilage damage is minimal. In addition, with the insertion of suture anchors, there is the possibility of joint penetration. The liberal use of fluoroscopy to document the position of the anchor insertion instrument before committing to a specific angle is critical to a successful procedure.

Summary

The mechanical effects of the labrum appear to substantiate the need to preserve as much tissue as possible. The effects of a decrease in synovial fluid within the weight-bearing dome of the acetabulum as a result of labral resection are probably detrimental on a long-term basis. Therefore, the treatment of patients who have mechanical symptoms with underlying labral pathology needs to be undertaken in a conservative fashion to alleviate symptoms while also preventing (or at least delaying) the development of degenerative changes.

There are key questions that remain to be answered with regard to the use of hip arthroscopy to treat lesions of the hip labrum. First, what are the long-term results of the arthroscopic debridement of tears of the hip labrum? The results of the procedure as compared with those of the natural history of tears are unknown. Second, and in conjunction with the first question, how do the short- and long-term results of the arthroscopic repair of the torn hip labrum compare with those of arthroscopic debridement?

The available literature supports the concept that the labrum is important for both stability and cartilage homeostasis. The long-term effects of repair or excision clearly need to be further analyzed. It is intuitively apparent that the preservation of as much relatively normal labral tissue as possible—with any surgical procedure—is critical to the long-term preservation of the native hip joint.

Annotated references and suggested readings

Burnett R.S., Della Rocca G.J., Prather H., et al. Clinical presentation of patients with tears of the acetabular labrum. J Bone Joint Surg Am.. 2007;88A:1448-1457.

Byrd J.W., Jones K.S. Prospective analysis of hip arthroscopy with 2-year follow-up. Arthroscopy. 2000;16:578-587.

Crawford M.J., Dy C.J., Alexander J.W., et al. The biomechanics of the hip labrum and the stability of the hip. J Orthop Res.. 2007;465:16-22.

This article is an analysis of the stability given to the hip by the labrum as well as of the clinical implications of disruption..

Espinosa N., Rothenfluh D.A., Beck M., et al. Treatment of femoro-acetabular impingement: Preliminary results of labral refixation. J Bone Joint Surg.. 2006;88A:925-935.

This is a clinical study with more than 2 years of follow-up regarding patients who underwent open femoral neck resection with labral refixation and who are compared with a group that underwent labral excision..

Farjo L.A., Glick J.M., Sampson T.G. Hip arthroscopy for acetabular labral tears. Arthroscopy. 1999;15:132-137.

Ferguson S.J., Bryant J.T., Ganz R., et al. The influence of the acetabular labrum on hip joint cartilage consolidation: a poroelastic finite element model. J Biomech.. 2000;33:953-960.

This is a finite element model description of the structure and function of the labrum. The implications of a disrupted labrum are also discussed..

Griffin D.R., Villar R.N. Complications of arthroscopy of the hip. J Bone Joint Surg.. 1991;81B:604-606.

This article includes a summary of 640 consecutive hip arthroscopies and the documentation of common complications..

Hines S.L., Philippon M.J., Kuppersmith D., et al. Early results of labral repair. Presented at 2007 annual AANA meeting. April 27, San Francisco, CA; 2007.

This article presents the early clinical results of a group of patients undergoing hip labral repairs.

Kelly B.T., Shapiro G.S., Digiovanni C.W., et al. Vascularity of the hip labrum: a cadaveric investigation. Arthroscopy.. 2005;21(1):3-11.

Kelly B.T., Weiland D.E., Schenker M.L., et al. Current concepts: arthroscopic labral repair in the hip: surgical technique and review of the literature. Arthroscopy.. 2005;21:1496-1504.

This article depicts the current understanding of hip labral repairs as well as various surgical techniques..

Lage L.A., Patel J.V., Villar R.N. The acetabular labral tear: an arthroscopic classification. Arthroscopy.. 1996;12:269-272.

This is a descriptive classification of the commonly encountered types of labral tears..

McCarthy J.C., Noble P.C., Schuck M.R., et al. The watershed labral lesion: its relationship to early arthritis of the hip. J Arthroplasty.. 2001;16(8 Suppl 1):81-87.

This article provides an analysis of the senior author’s patients and the description of a pathomechanical model that leads to chondral delamination in the absence of bony impingement..

Murphy K.P., Ross A.E., Javernick A., et al. Repair of the adult acetabular labrum. Arthroscopy.. 2006;22:e3.

This article presents the result of a small series of patients with short-term follow-up after the labral repair of the hip..

O’Leary J.A., Bernard K., Vail T.P. The relationship between diagnosis and outcome in arthroscopy of the hip. Arthroscopy. 2001;17:181-188.

Potter B.K., Freedman B.A., Andersen R.C., et al. Correlation of short form-36 and disability status with outcomes of arthroscopic labral debridement. Am J Sports Med. 2005;33:864-870.

Ross A.E., Javernick M., Freedman B., et al. Arthroscopic hip labral repair. Arthroscopy.. 2006;22:e30.

Santorini N, Villar R.N. Acetabular labral tears: result of arthroscopic partial limbectomy. Arthroscopy. 2000;16:11-15.

Seldes R.M., Tan V., Hunt J., et al. Anatomy, histologic features, and vascularity of the adult acetabular labrum. Clin Orthop.. 2001;382:232-240.

This descriptive classification correlates the type of tear encountered with the type of clinical pathology. The classification is based on the histologic analysis of tears..

Toomayan F.A., Holman W.R., Major N.M., et al. Sensitivity of MR arthrography in the evaluation of acetabular labral tears. AJR Am J Roentgenol.. 2006;186(2):449-453.

This article compares plain magnetic resonance imaging with MRA and includes a discussion of some of the standard techniques..

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