Repair of the adult acetabular labrum

Capsular ligaments provide a passive stabilizing force to protect the hip against edge loading

AIMS

In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading.

METHODS

Torque-rotation curves were obtained from nine cadaveric hips to define the rotational restraint contributions of the capsular ligaments in 36 positions. A ligament model was developed to determine the line-of-action and effective moment arms of the medial/lateral iliofemoral, ischiofemoral, and pubofemoral ligaments in all positions. The functioning ligament forces and stiffness were determined at 5 Nm rotational restraint. In each position, the contribution of engaged capsular ligaments to the joint reaction force was used to evaluate the net force vector generated by the capsule.

RESULTS

The medial and lateral arms of the iliofemoral ligament generated the highest inbound force vector in positions combining extension and adduction providing anterior stability. The ischiofemoral ligament generated the highest inbound force in flexion with adduction and internal rotation (FADIR), reducing the risk of posterior dislocation. In this position the hip joint reaction force moved 0.8° inbound per Nm of internal capsular restraint, preventing edge loading.

CONCLUSION

The capsular ligaments contribute to keep the joint force vector inbound from the edge of the acetabulum at extreme ROM. Preservation and appropriate tensioning of these structures following any type of hip surgery may be crucial to minimizing complications related to joint instability. Cite this article: Bone Joint Res 2021;10(9):594-601.

Perpendicular drill bit alignment provides a practical guidance to determine the appropriate suture anchor insertion angle during acetabular labral repair

The safe acetabular rim angle is an anatomical measurement used to determine the safety margin when inserting suture anchors. The purpose of the present study was to find out whether aligning the drill bit perpendicularly during arthroscopic surgery can provide a reference point for determining an appropriate angle to facilitate the suture anchor insertion and to prevent extra- and intra-articular perforations. One hundred computed tomographic hips were used to reconstruct three-dimensional acetabular hip models. Each model was radially sectioned at the 4 o’clock, 3 o’clock and anterior inferior iliac spine (AIIS) positions (that corresponded mainly to the 2:20 clock position). A perpendicular reference line, representing a perpendicular drill bit alignment, was drawn for each position within the acetabular model, and its relation to the safe acetabular rim angle was measured. The length of the perpendicular reference line and the effect of gender on measurements were also evaluated. The mean safe acetabular rim angle at the 3 o’clock position was significantly smaller compared to other clock positions (P < 0.001). The perpendicular reference line was located out of the safe acetabular rim angle in 28 cases (%28), mostly in female acetabula at the 3 o’clock position, and relative to the perpendicular reference line the required minimal angle was 4° ± 2.3° to place the anchor in the safe acetabular rim angle to avoid extra-articular perforation. The perpendicular reference line was shortest at the 3 o’clock position, and its mean length was shorter in female acetabula at all clock positions (P < 0.001). Aligning the drill bit perpendicular to the acetabular opening plane during an arthroscopic anchor placement is a practical way to estimate and target the position of the safe acetabular rim angle to avoid anchor perforations. Based on measurements from a perpendicularly aligned drill bit, the drill bit should be directed towards the joint minimally by 4° to avoid extra-articular perforations and maximally by 30° to avoid intra-articular perforations.

Repaired or unrepaired capsulotomy after hip arthroscopy: a systematic review and meta-analysis of comparative studies

PURPOSE

To conduct a systematic review and meta-analysis comparing the surgical techniques, clinical outcomes, rates of revision and conversion to arthroplasty and complications between a repaired and unrepaired capsulotomy after hip arthroscopy.

METHODS

A search of the PubMed, Embase and Google Scholar databases was performed to identify comparative articles published prior to 10 July 2019 that reported the capsule management strategy and clinical outcomes after hip arthroscopy. A narrative analysis and meta-analysis were performed to integrate and compare the results of the 2 groups.

RESULTS

12 comparative studies (n = 1185 hips) with an average (methodological index for non-randomized studies) MINORS score of 17.45 ± 2.02 were identified for analysis, of which 5 were included in the meta-analysis. The pre- to postoperative improvements in the modified Harris Hip Score (mHHS), Hip Outcome Score-Sport-Specific Subscale (HOS-SS), and Hip Outcome Score-Activities of Daily Living (HOS-ADL) revealed no significant differences between the repaired and unrepaired groups (p = 0.40, 0.26 and 0.61, respectively). The risk ratio of the revision rate for the 2 groups was 0.66 (p = 0.21). Evaluation of the MRI scans and the rate of heterotopic ossification also showed no significant differences. The most preferred capsulotomy techniques were interportal and T-shape. No postoperative hip instability was reported in any of the 12 studies.

CONCLUSION

The currently published evidence is still not strong enough to confirm the superiority of repairing the capsule after hip arthroscopy; hence, routine repair of the capsule during surgery cannot be suggested.

The dimensions of the hip capsule can be measured using magnetic resonance imaging and may have a role in arthroscopic planning

PURPOSE

The purpose of this study was to systematically evaluate the dimensions and thickness of the hip joint capsule. Secondarily, the study assessed whether there were any described correlations between capsule thickness and stability of the hip joint.

METHODS

Four databases (PubMed, Ovid [MEDLINE], Cochrane Database, and EMBASE) were searched from database inception to May 2018, and two reviewers independently and in duplicate screened the resulting literature. Methodological quality of all included papers was assessed using the Methodological index for non-randomized studies (MINORS) criteria. Mean differences were combined in a meta-analysis using a random effects model when possible.

RESULTS

A total of 14 studies (1 level I, 1 level II, 4 level III, 5 level IV) were identified including 796 patients (1013 hips) with a mean age of 39.5 years (range 2-95). Of the included patients, 55.2% were female and they were followed up for a mean of 7.6 months (range 1-12.5 months). The thickness of the capsule was measured in cadaveric specimens, ultrasound, and magnetic resonance imaging (MRI), with MRI measurements reported most consistently and with the least variation. Mean thickness of the anterior capsule in patients without hip disease on MRI ranged from 4.4 and 4.7 mm. Mean thickness of the anterior capsule in patients with FAI ranged between 4.9 and 5.0 mm. Males had significantly thicker capsules than females (mean difference = 1.92 mm, 0.35-3.49, P = 0.02). Clinical laxity of the hip joint, as well as female gender was correlated with thinner anterior joint capsules.

CONCLUSION

The thickness of the anterior hip capsule can be measured consistently using MRI. A thinner anterior capsule may be associated with clinical laxity of the hip joint. The relevance of capsular thickness on postoperative instability following hip arthroscopy is poorly understood and warrants further investigation. The thickness of the anterior hip capsule, as measured on MRI, has the potential to be used as part of the clinical decision-making in capsular management strategies.

LEVEL OF EVIDENCE

IV.

Clinical and radiological outcome at mean follow-up of 11 years after hip arthroscopy

INTRODUCTION

The use of hip arthroscopy (HA) has substantially increased over the last decade. However, while the benefits of HA after 1 year in patients with femoroacetabular impingement (FAI) are well documented, long-term data on the progression of osteoarthritis (OA) or patient-reported outcomes (PROMs) are lacking.

OBJECTIVES

To evaluate long-term clinical and radiological outcomes after HA.

MATERIALS AND METHODS

Preoperative clinical records, operative notes, and radiographs from all patients who underwent HA at our hospital between 1998 and 2006 were reviewed. Exclusion criteria were previous hip surgery or diagnostic HA. Primary endpoints were subsequent total hip arthroplasty (THA) or other hip surgery. Secondary endpoints were OA progression and PROMs.

RESULTS

HA was performed in 92 consecutive patients from 1998 to 2006. Indications for HA were FAI, labral lesions, early OA, and focal osteochondral defects. Mean follow-up was 11.2 years (SD 2.5, range 7.9-16). Data from 43 patients were available for analysis; 38 patients were excluded, and 11 were lost to follow-up. 20 patients had subsequent hip surgery, of which 11 patients required THA. 33 patients (77%) stated that they would undergo HA again under the same circumstances. Longitudinal radiological analysis showed no significant OA progression in patients without THA. The Forgotten Joint Score-12 was the only PROM to significantly differ between patients who had no further surgery and patients who had undergone revision (p = 0.037).

CONCLUSION

There was no significant OA progression on plain radiography at an average of 11 years post-HA. Sound indication criteria is essential, as 45% of patients required subsequent surgery.

MRI Evaluation of Repaired Versus Unrepaired Interportal Capsulotomy in Simultaneous Bilateral Hip Arthroscopy: A Double-Blind, Randomized Controlled Trial

BACKGROUND

Techniques used in hip arthroscopy continue to evolve, and controversy surrounds the need for capsular repair following this surgical intervention. The purpose of this study was to evaluate the magnetic resonance imaging (MRI) appearance of the hip capsule in patients with femoroacetabular impingement (FAI) who underwent simultaneous bilateral hip arthroscopy through an interportal capsulotomy with each hip randomized to undergo capsular repair or not undergo such a repair.

METHODS

This double-blind, randomized controlled trial included 15 patients (30 hips), with a mean age of 29.2 years, who underwent simultaneous bilateral hip arthroscopy utilizing a small (<3-cm) interportal capsulotomy for the treatment of FAI. The first hip treated in each patient was intraoperatively randomized to undergo capsular repair or no capsular repair. The contralateral hip then received the opposite treatment. MRI was performed at 6 and 24 weeks postoperatively, and the scans were analyzed by 2 musculoskeletal radiologists. The patients and the radiologists were blinded to the treatment performed on each hip. Capsular dimensions were measured at the level of the healing capsulotomy site and, for hips with a persistent defect, at locations both proximal and distal to the defect. These values were then analyzed at both time points to assess the rate and extent of capsular healing.

RESULTS

At 6 weeks postoperatively, a continuous hip capsule (with no apparent capsulotomy defect) was observed in 8 hips treated with capsular repair and 3 hips without such a repair. Of the 19 hips with a discontinuous capsule at 6 weeks, 17 were available for follow-up at 24 weeks postoperatively; all 17 demonstrated progression to healing, with a contiguous appearance without defects and no difference in capsular dimensions between treatment cohorts.

CONCLUSIONS

Arthroscopic repair of a small interportal hip capsulotomy site yields an insignificant increase in the percentage of continuous hip capsules seen on MRI at 6 weeks postoperatively compared with no repair. Repaired and unrepaired capsulotomy sites progressed to healing with a contiguous appearance on MRI by 24 weeks postoperatively.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Arthroscopic Labral Base Repair in the Hip: 5-Year Minimum Clinical Outcomes

BACKGROUND

Arthroscopic labral base repair (LBR) in the hip is a previously described technique designed to restore the native functional anatomy of the labrum by reproducing its seal against the femoral head. LBR has been shown to have good short-term outcomes. Hypothesis/Purpose: The purpose was to evaluate clinical outcomes of an LBR cohort with a minimum 5-year follow-up. It was hypothesized that patients who underwent LBR would continue to have significant improvement from their preoperative scores and maintain scores similar to their 2-year outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data for patients undergoing primary hip arthroscopic surgery with LBR from February 2008 to May 2011 with a minimum 5-year follow-up were prospectively collected and retrospectively reviewed. Patients with preoperative Tonnis osteoarthritis grade ≥2, previous hip conditions (slipped capital femoral epiphysis, avascular necrosis, Legg-Calv-Perthes disease), severe dysplasia (lateral center-edge angle <18°), or previous ipsilateral hip surgery were excluded. Statistical equivalence tests evaluated patient-reported outcomes (PROs) including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale (HOS-SSS), visual analog scale (VAS) for pain, and patient satisfaction (0-10 scale; 10 = very satisfied).

RESULTS

Of the 70 patients (74 hips) who met inclusion and exclusion criteria, 60 (85.7%) patients (64 hips) were available at a minimum 5-year follow-up. All PRO scores significantly improved from preoperative values with a mean follow-up of 67.8 ± 7.4 months (range, 60.0-89.7 months). The mean mHHS increased from 64.4 ±13.8 to 85.3 ± 17.7 ( P < .001), the mean NAHS from 63.7 ± 17.0 to 87.0 ± 14.7 ( P < .001), and the mean HOS-SSS from 47.1 ± 23.2 to 76.5 ± 25.9 ( P < .001). The mean VAS score decreased from 5.9 ± 2.4 to 2.0 ± 2.1 ( P < .001). The mean patient satisfaction score was 8.1 ± 2.0. The improvement in PRO scores was sustained from 2- to 5-year follow-up. At 2 and 5 years, survivorship rates were 96.9% and 90.6%, respectively, and the respective secondary arthroscopic surgery rates were 10.9% (7/64) and 17.2% (11/64).

CONCLUSION

At a minimum 5-year follow-up, arthroscopic LBR continued to be a successful procedure and valid technique based on 3 PROs, the VAS, patient satisfaction, and survivorship. Significantly improved outcome scores were maintained compared with preoperative values and showed no signs of deterioration from the 2-year scores. The long-term survivorship of hip arthroscopic surgery has yet to be determined; however, these midterm results demonstrate the rates of additional procedures (both secondary arthroscopic surgery and conversion to total hip arthroplasty), that may be necessary after 2 years.

Are pelvic anatomical structures in danger during arthroscopic acetabular labral repair? Definition of safe bone depth

PURPOSE

The purpose of this study was to evaluate safe depth for suture anchor insertion during acetabular labral repair and to determine the neighbouring structures at risk during drilling and anchor insertion.

METHODS

Ten human cadaveric hips (six males and four females) were obtained. Acetabular labral surface was prepared and marked for right hips as 12, 1 and 3 o'clock positions, for left hips 12, 11 and 9 o'clock positions. Those were defined as anterior, anterior-superior and superior zones, respectively. These labral positions were drilled at defined zones. After measurements, depth of the bone at 10° and 20° drill angles on zones was compared statistically.

RESULTS

Acetabular bone widths at investigated labral insertion points did not statistically differ. A total of 14 injuries in 60 penetrations occurred (23.3 %) with free drill penetrations, and no injuries occurred with stopped drill penetrations. The bone depth was gradually decreasing from 10° to 20° drill angles and from anterior to superior inserting zones without significant importance. The risk of perforation to the pelvic cavity started with 20 mm drill depth, and the mean depth for all insertions was calculated as 31.7 mm (SD 2.6).

CONCLUSIONS

It is anatomically possible that some pelvic structures sustain iatrogenic injury during acetabular drilling for anchor placement. Being aware of mean pelvic vault is important in which drilling after excessive pincer rim trimming could easily decrease the depth of acetabular bone without a standard. Careful drilling by using stopped drill bit is crucial to prevent iatrogenic injury.

Anatomic Labral Repair in the Hip Using a Knotless Tensionable Suture Anchor

To perform a proper labral repair, most surgeons use anchors to secure the labrum to the acetabular bone. We aim to describe a technique for labral repair with a knotless tensionable suture anchor. This technique uses a looped suture configuration, allowing selective tensioning of the repair to maintain the anatomic suction seal of the hip. The use of this technique is easily reproducible and reduces the surgical time compared with previous techniques.

Allograft Use in Arthroscopic Labral Reconstruction of the Hip With Front-to-Back Fixation Technique: Minimum 2-Year Follow-up

PURPOSE

To present minimum 2-year outcomes in patients who underwent a modified technique for arthroscopic labral reconstruction using iliotibial band allograft tissue and a front-to-back fixation.

METHODS

From April 2011 to July 2012, all consecutive arthroscopic labral reconstruction patients were included in this Institutional Review Board-approved, prospective case series study. Inclusion criteria were arthroscopic iliotibial band allograft labral reconstruction performed by a single surgeon, age ≥16 years at the time of arthroscopy, and a minimum of 2 years of follow-up. Patients completed subjective questionnaires both preoperatively and postoperatively, including Modified Harris Hip Score (MHHS), the Lower Extremity Function Score (LEFS), Visual Analogue Scale (VAS) pain scores, and patient satisfaction. A modified front-to-back fixation technique for labral reconstruction was used.

RESULTS

One hundred fifty-two hips (142 patients) met the inclusion criteria for this study; 131 hips (86.2%) had complete follow-up at a minimum of 2 years, and 21 hips (13.8%) were lost to follow-up or had incomplete data during the study period. Seventy hips had concomitant procedures performed; 27 microfracture, 30 chondroplasty, 26 psoas release, 5 os acetabuli resection, and 3 Ganz osteotomy. Overall, 18 hips (13.7%) required revision procedures at a mean of 17 months (range, 1 to 37 months) after the labral reconstruction. In the remaining 113 hips, there was significant improvement in all outcome measures from preoperative to most recent follow-up (P < .0001). The mean MHHS improved by 34 points (P < .0001), and the mean LEFS improved by 27 points (P < .0001). The mean VAS pain score improved by 3 points at rest (P < .0001), 4 points with average pain with daily activities (P < .0001), and 5 points with sport (P < .0001). Patients reported an overall satisfaction of 9 (range, 1 to 10).

CONCLUSIONS

Arthroscopic iliotibial band allograft labral reconstruction of the hip shows promising outcomes at minimum 2-year follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic treatment of femoroacetabular impingement: minimum five-year follow-up

PURPOSE

To evaluate the clinical outcomes of an arthroscopic treatment of femoroacetabular impingement at a minimum of a five-year follow-up.

METHODS

A case series with 24 subjects (26 hips) was conducted. Subjects that were submitted to an arthroscopic procedure for the treatment of femoroacetabular impingement, at a minimum of five years, were evaluated. Subjects completed the modified Harris Hip Score (mHHS), the pain numeric rating scale and a general questionnaire accessing sports practice and satisfaction.

RESULTS

Twenty-one of the 24 subjects (87.5%) were male and the average age at the time of surgery was 34.6 ± 9.5 years old (range 13-51). Of the 27 subjects submitted to hip arthroscopy, three (11.1%) could not be contacted. Follow-up was 6.1 ± 0.8 years, and at this time the average mHHS was 90.6 ± 11.6. Pain numeric rating scale was 2.6 ± 1.9 and 11 hips (42.3%) reported no pain. Of the 14 subjects that complained of hip pain during sports activities prior to surgery, 10 (71.4%) returned to normal sports activities while four (28.6%) subjects could not return to preoperative activities. Three patients had to be submitted to a new surgical procedure. All 24 subjects were satisfied with their procedure and would repeat it if necessary.

CONCLUSIONS

Arthroscopic treatment of femoroacetabular impingement, at five years follow-up, revealed good results in terms of improved function, pain relief and satisfaction.

Arthroscopic labral repair of the hip, using a through-labral double-stranded single-pass suture technique

The normal labrum is crucial to the biomechanical function of the hip joint, not only increasing the surface area and depth of the acetabulum but also maintaining a suction seal to assist in normal synovial fluid flow from the peripheral to the central compartment. Simple loop suture repairs of the labrum may evert the labrum, thus losing the optimal seal, as well as causing abrasion of the articular cartilage. Vertical mattress suture and labral base fixation techniques aim to leave the free edge of the labrum intact and undisturbed, therefore improving the contact of the labrum to the femoral head and neck to improve the seal of the acetabulum. We aim to describe a double-stranded single-pass vertical mattress suture technique that may allow greater versatility to the surgeon in repairing thinner labrums while still achieving a free and continuous free edge.

Primary repair of the acetabular labrum: outcomes with 2 years' follow-up

PURPOSE

The purpose of this study was to assess the results and outcomes of primary repair of the torn acetabular labrum.

METHODS

All patients undergoing hip arthroscopy are prospectively assessed solely with the modified Harris Hip Score, which is an outcomes tool. Over a 4-year period, 37 patients (38 hips) underwent primary repair of a torn acetabular labrum and had reached 2 years' follow-up. No cases were excluded. For perspective on the frequency of this procedure, the ratio of labral refixations after pincer femoroacetabular impingement correction to primary repairs was evaluated.

RESULTS

The mean age was 26 years (range, 11 to 44 years). There were 26 female and 11 male patients, with 20 right and 18 left hips. The mean improvement in the modified Harris Hip Score was 18.9 points (70.5 points preoperatively and 89.4 points postoperatively), with 35 hips (92%) showing improvement, including good and excellent results in 35 hips (92%). Associated pathology included articular damage (21 hips), ligamentum teres (14 hips), cam femoroacetabular impingement (11 hips), borderline dysplasia (center-edge angle, 20° to 25°) (3 hips), dysplasia (center-edge angle <20°) (2 hips), and iliopsoas (2 hips). Four patients underwent repeat arthroscopy at a mean of 10 months (range, 5 to 15 months) postoperatively. The labral repair site was fully healed in each of these cases. There were no complications. During the study period, a total of 1,574 arthroscopic hip procedures were performed, including 439 labral refixations, representing an 11.6:1 ratio of refixation to repair.

CONCLUSIONS

This study showed good clinical results of primary repair with favorable outcomes and evidence of good healing, even among the 11% of patients who required repeat arthroscopy.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Preoperative L1 and L2 paravertebral block is an effective postoperative analgesia for hip arthroscopy in a multimodal analgesic regimen

We describe the case of a 30-year-old woman with chronic hip pain secondary to avascular necrosis. She received preoperative L1-L2 paravertebral block for postoperative pain control after arthroscopic hip surgery. Preoperative paravertebral block at the level of L1-L2 provided an effective postoperative analgesia for hip arthroscopy when used in a multimodal approach.

Save the torn labrum in hips with borderline acetabular coverage

BACKGROUND

Hip arthroscopy for labral tears improves short-term function, but reoperations occur in 5% to 47% of patients. The effect of borderline acetabular coverage on reoperation rate has been debated. Labral repair rather than débridement has been proposed to improve function, but the effect on reoperation rate is unclear.

QUESTIONS/PURPOSES

We determined whether (1) borderline compared to adequate acetabular coverage increased reoperations and (2) labral repair compared to débridement reduced reoperations.

METHODS

We retrospectively reviewed 106 patients (mean age, 39 years) who underwent hip arthroscopy for labral tears. Based on radiographs, we classified patients into those with borderline (n = 50) or adequate (n = 56) acetabular coverage. We further divided each group into those with labral débridement or repair: borderline acetabular coverage, n = 25 and 25, respectively; adequate acetabular coverage, n = 39 and 17, respectively. We assessed reoperations in borderline versus adequate acetabular coverage and labral débridement versus repair, modified Harris hip scores (mHHSs), and survival. Minimum followup was 12 months (mean, 33 months; range, 12-65 months).

RESULTS

Twenty-three of 106 patients had reoperations. Reoperation rate was higher with borderline than with adequate acetabular coverage. Reoperation rate was lower with labral repair than with débridement. Survival to reoperation was similar in the four subgroups although there was a tendency for early reoperation in patients with borderline acetabular coverage with débridement. Improvement in mean mHHS was comparable in the four subgroups.

CONCLUSIONS

We found borderline acetabular coverage increased reoperation rates. Labral repair reduced the likelihood of reoperation, especially in hips with borderline acetabular coverage. Hip arthroscopy for labral tears was associated with high reoperation rates in hips with borderline acetabular coverage.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Investigation of the preservation of the fluid seal effect in the repaired, partially resected, and reconstructed acetabular labrum in a cadaveric hip model

BACKGROUND

Debate exists on whether hip labral tears should be surgically repaired, partially resected, or reconstructed. Furthermore, limited data exist regarding the fluid seal properties of hip labrum repair and/or reconstruction with iliotibial band autograft when compared with the labrum-intact condition. Hypothesis/

PURPOSE

The purpose of this study was to investigate the fluid seal properties of hip labral repair and reconstruction techniques. We hypothesized that hip labral repair preserves the acetabular labral fluid seal greater than labral tear, partial-resection, and reconstruction conditions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six human cadaveric hemipelvises were dissected of all soft tissue, leaving the hip capsule intact. Fluid efflux was measured under 5 conditions using a custom fluid infusion device: (1) hip labrum intact, (2) labral tear, (3) labral repair with suture anchors, (4) partial labral resection, and (5) labral reconstruction using ipsilateral iliotibial band autograft. Joint fluid expression was measured as flow rate under 3 different pressure settings (2, 3, and 4 psi). Statistical differences between conditions were assessed using 2-way, repeated-measures analysis of variance. The Student-Newman-Keuls (SNK) multiple comparison test was used to determine differences between levels.

RESULTS

There was a significant increase in fluid efflux with a simulated labral tear (0.54 ± 0.3 mL/sec) when compared with the intact hip labrum condition (0.006 ± 0.008 mL/sec, P < .05). The labrum-repaired condition (0.21 ± 0.2 mL/sec) demonstrated significantly less fluid efflux when compared with the labral-tear condition. Hip labral repair significantly prevented greater fluid efflux when compared with partial labral resection (0.60 ± 0.4 mL/sec) and reconstruction with iliotibial band autograft (0.54 ± 0.3 mL/sec; P < .05). Labral repair did not preserve fluid efflux as effectively as in the labrum-intact condition (0.21 ± 0.2 > 0.006 ± 0.008 mL/sec; P < .05). There was no difference observed in fluid efflux between the labral reconstruction, tear, or resection conditions (P > .05).

CONCLUSION

In this human cadaveric model, hip labral repair outperforms partial labral resection and reconstruction in preserving the joint fluid seal; however labral repair does not restore fluid seal characteristics as effectively as in the labrum-intact condition.

CLINICAL RELEVANCE

Further prospective studies are needed to determine whether hip labral repair outperforms partial labral resection and/or reconstruction in clinical practice.

Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement: mean 3.5-year follow-up

BACKGROUND

The acetabular labrum provides a sealing function and a degree of hip joint stability. Limited, short-term follow-up studies suggest that labral refixation/preservation leads to superior outcomes compared with labral debridement/excision.

PURPOSE

To compare the results of labral refixation versus focal labral excision/debridement in a cohort of patients who underwent arthroscopic correction of femoroacetabular impingement (FAI).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We reported on patients who underwent labral debridement/focal labral excision during a period before the development of labral repair techniques. Patients with labral tears thought to be repairable with our current arthroscopic technique were compared with a cohort of patients who underwent labral refixation. To better match the 2 groups, only patients with labral pincer- or combined-type FAI were included. In the first 44 hips, the labrum was focally excised/debrided (group 1); in the next 50 hips, the labrum was refixed (group 2). Outcomes were measured with the modified Harris Hip Score (HHS), Short Form 12 (SF-12), and a visual analog scale (VAS) for pain preoperatively and postoperatively. Preoperative and postoperative radiographs were obtained to evaluate bony resection.

RESULTS

The mean age was 32 years in group 1 and 28 years in group 2 with a mean follow-up of 42 months (range, 24-72 months). Preoperative mean subjective outcome scores were not significantly different between groups. At a mean 3.5 years' follow-up, subjective outcomes were significantly improved (P < .01) for both groups compared with preoperative scores. The HHS (P = .001), SF-12 (P = .041), and VAS pain scores (P = .004) were all significantly better for the refixation group compared with the debridement group at the most recent follow-up. At a mean 3.5 years' follow-up, good to excellent results were noted in 68% of the focal excision/debridement group and 92% of the refixation group (P = .004).

CONCLUSION

Although other factors may have influenced these results, labral refixation compared with an earlier cohort of focal labral excision/debridement resulted in better HHS, SF-12, and VAS pain outcomes and a greater percentage of good to excellent results at a mean 3.5-year follow-up.

Long-term results of arthroscopic labral debridement: predictors of outcomes

Limited data exist regarding the long-term results of labral debridement and the effect of coexisting pathology on outcomes. Our hypothesis was that untreated coexisting hip pathologies such as femoroacetabular impingement and arthritis significantly affect the outcomes of arthroscopic labral debridement. Between 1996 and 2003, fifty consecutive patients who underwent hip arthroscopy and labral debridement with a mean follow-up of 8.4 years were included in our study. Patients' preoperative Harris Hip Scores and coexisting pathologies such as femoroacetabular impingement, dysplasia, or arthritis were recorded as variables. Postoperative Harris Hip Score and satisfaction at final follow-up were recorded as outcomes. Good or excellent results were achieved in 62% of cases (58% in patients with untreated femoroacetabular impingement and 19% in patients with arthritis). Failures included 2 cases that were converted to total hip replacement (4.5 and 5.2 years after index procedure) due to advancement of arthritis and 1 case of repeat arthroscopy for cam decompression. Patients with no coexisting pathology had significantly higher satisfaction and Harris Hip Scores. Almost all of the patients with low postoperative Harris Hip Scores had arthritic changes. Arthritis had a significant correlation with low postoperative Harris Hip Scores and satisfaction. Coexisting pathology, especially arthritis and untreated femoroacetabular impingement, can result in inferior outcomes. Arthroscopic labral debridement of symptomatic tears in selected patients with no coexisting pathology can result in favorable long-term results. Arthritis is the strongest independent predictor of poor outcomes.

Vascular supply to the acetabular labrum

BACKGROUND

The acetabular labrum plays an important role in hip joint stability and protection of the articular cartilage of the hip. Despite this, few investigators have evaluated its microscopic vasculature and, to our knowledge, none has assessed its macroscopic blood supply. The purposes of this study were to identify the origin and course of the vascular supply to the acetabular labrum to determine if this blood supply is affected by a labral tear.

METHODS

Colored silicone was injected into the vascular tree proximal to thirty-five hips in twenty-eight fresh cadavers. Twenty-four hours after injection, anatomic dissection was performed and the vessels supplying the labrum were followed from their origin to their final distribution. Additionally, labral segments of fifteen randomly selected hips were resected to assess the acetabular rim's vascular contribution, and fifteen hips were dislocated for complete intra-articular inspection of the labrum.

RESULTS

Radial branches of a previously described periacetabular periosteal vascular ring were identified as the source of labral blood supply in all thirty-five hips. These branches coursed toward the hip joint on the periosteal surface, penetrated the joint capsule near its innominate insertion, and continued within a loose connective-tissue layer on the capsular surface of the labrum. No contribution from the hip capsule, synovial lining, or osseous acetabular rim could be demonstrated. An intact vascular supply was identified in all seven hips with a labral tear.

CONCLUSIONS

The acetabular labrum receives its blood supply from radial branches of a periacetabular periosteal vascular ring that traverses the osseolabral junction on its capsular side and continues toward the labrum's free edge. The hip capsule, the synovial lining, and the osseous acetabular rim do not appear to provide substantial contributions to the labral blood supply.

Labral base refixation in the hip: rationale and technique for an anatomic approach to labral repair

Recent literature has defined the importance of anatomic repair in shoulder and knee arthroscopy. New advances in hip arthroscopy have created opportunities to apply the principle of anatomic repair to the hip. To address the obstacles in the restoration of labral anatomy, we describe an anatomic approach to labral refixation. We reviewed the literature on biomechanics of the labrum to identify the factors that are essential to the function of the labrum. Existing techniques for arthroscopic labral repair and potential challenges in restoration of labral anatomy were reviewed. A list of criteria for anatomic labral repair was created, and a technique for anatomic labral base refixation was developed. The technique incorporates the understanding of the function and biomechanical role of the labrum and builds on existing techniques to fulfill the criteria for restoration of anatomy. Our purpose was to review the anatomy, biomechanics, and existing repair techniques of the labrum, as well as to describe the rationale and surgical steps for anatomic labral base refixation in the hip.

Arthroscopic anterior and posterior labral repair after traumatic hip dislocation: case report and review of the literature

With the improvements in flexible instrumentation, hip arthroscopy is being increasingly used to treat a variety of hip pathology, including labral tears. However, up to this point, there has not been a case report of an anterior and a posterior labral tear successfully repaired arthroscopically. We present a case report of a 27-year-old male firefighter who presented to our institution with an anterior and posterior labral tear, as well as a cam lesion and loose body, following a traumatic hip dislocation. The purpose of this case report is to illustrate that both anterior and posterior labral tears can be repaired using hip arthroscopy. Anterior and posterior labral tears can be caused by a traumatic hip dislocation, and both can be successfully repaired using arthroscopic techniques.

A clinically relevant review of hip biomechanics

The hip is a complex anatomic structure composed of osseous, ligamentous, and muscular structures responsible for transferring the weight of the body from the axial skeleton into the lower extremities. This must be accomplished while allowing for dynamic loading during activities such as gait and balance. The evaluation of hip pain and periarticular pathology can be challenging because of the complex local anatomy and broad differential diagnosis. Recent advancements in the evaluation and surgical treatment of hip pathology have led to a renewed interest in the management of these disorders. An understanding of the basic biomechanical and kinematic function of the hip and the consequences of associated pathology can greatly assist the orthopaedic surgeon in appropriately diagnosing and treating these problems. In this review we discuss the basic biomechanical concepts of the native hip and surrounding structures and the changes experienced as a result of various pathologies including dysplasia, femoroacetabular impingement, labral injury, capsular laxity, hip instability, and articular cartilage injury. We will also discuss the clinical implications and surgical management of these pathologies and their role in restoring or preserving the native function of the hip joint.

The acetabular labrum: anatomic and functional characteristics and rationale for surgical intervention

The past decade has seen unprecedented growth in the number of hip arthroscopies. Acetabular labral tears are the leading indication for arthroscopy of this joint. However, labral anatomy and function, as well as the effects of labral tears and surgical outcomes, have only recently been studied. Labral tears may cause pain and microinstability of the hip joint. They also may increase friction within the joint, cartilage consolidation, and strain within the articular cartilage, thereby possibly resulting in accelerated degeneration of the joint. Partial labrectomy and labral repair are the current surgical options, and basic science data suggest that labral repairs can heal and subsequently restore function. However, a good, validated outcomes measure to adequately assess active patients with a painful nonarthritic hip is needed to determine the efficacy of such repair and aid in managing patient expectations.

Arthroscopic labral reconstruction in the hip using iliotibial band autograft: technique and early outcomes

PURPOSE

The purpose of this study was to investigate the indications for and outcomes of arthroscopic labral reconstruction in the hip by use of iliotibial band (ITB) autograft.

METHODS

Between August 2005 and May 2008, the senior author (M.J.P.) performed 95 arthroscopic labral reconstructions using an ITB autograft in patients with advanced labral degeneration or deficiency. There were 47 patients who had undergone surgery at a minimum of 1 year previously and met the inclusion criteria. The modified Harris Hip Score (MHHS) and patient satisfaction were used to measure outcomes postoperatively. The labral autograft was harvested from the ITB through a separate incision. The graft was sutured to the intact labral remnant in the region of labral deficiency, re-establishing the suction seal of the hip joint.

RESULTS

There were 32 men and 15 women. The mean age at the time of surgery was 37 years (range, 18 to 55 years). The mean time from the onset of symptoms to labral reconstruction was 36 months (range, 1 month to 12 years). Subsequent total hip arthroplasty was performed in 4 patients (9%). Follow-up was obtained in 37 of the remaining 43 patients. The mean time to follow-up was 18 months (range, 12 to 32 months). The mean MHHS improved from 62 (range, 35 to 92) preoperatively to 85 (range, 53 to 100) postoperatively (P = .001). Median patient satisfaction was 8 out of 10 (range, 1 to 10). Patients who were treated within 1 year of injury had higher MHHSs than patients who waited longer than 1 year (93 v 81, P = .03). The independent predictor of patient satisfaction with outcome after labral reconstruction was age.

CONCLUSIONS

This study showed that patients who have labral deficiency or advanced labral degeneration had good outcomes and high patient satisfaction after arthroscopic intervention with acetabular labral reconstruction. Lower satisfaction was associated with joint space narrowing and increased age. Patients who waited longer than 1 year from the time of injury to surgery had lower function at follow-up than those treated in the first year.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Prospective analysis of hip arthroscopy with 10-year followup

Arthroscopic surgery of the hip is a well-established technique with numerous recognized indications. Despite the well-accepted nature of this procedure, there have been no outcomes studies with extended followup. We investigated the response to hip arthroscopy in a consecutive series of patients with 10 years followup. Since 1993, all patients undergoing hip arthroscopy have been assessed prospectively with a modified Harris hip score preoperatively and then postoperatively at 3, 12, 24, 60, and 120 months. A cohort of 50 patients (52 hips) was identified who had achieved 10-year followup and represent the substance of this study. There was 100% followup. The average age of the patients was 38 years (range, 14-84 years), with 27 males and 23 females. The median improvement was 25 points (preoperative, 56 points; postoperative, 81 points). Fourteen patients were converted to THA and two died. Four patients underwent repeat arthroscopy. There were two complications in one patient. The presence of arthritis at the time of the index procedure was an indicator of poor prognosis. This study substantiates the long-term effectiveness of arthroscopy in the hip as treatment for various disorders, including labral pathology, chondral damage, synovitis, and loose bodies. Arthritis is an indicator of poor long-term outcomes with these reported methods.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Variations in serum electrolyte concentrations and renal function after therapeutic hip arthroscopy: a pilot study

PURPOSE

The purpose of this study was to analyze changes in serum electrolyte concentration and renal function after hip arthroscopy.

METHODS

We studied 10 consecutive patients (4 men and 6 women; median age, 30.5 years [range, 20 to 50 years]) undergoing hip arthroscopy. Operating time, traction time, and perfusion volume of lactated Ringer solution (in milliliters) were recorded. Preoperative and postoperative levels of sodium (Na(+)), potassium (K(+)), cloride (Cl(-)), calcium (Ca(2+)), magnesium (Mg(2+)), phosphorous (P), creatinine, and blood urea nitrogen (BUN) were compared.

RESULTS

The median operating time was 80 minutes (range, 60 to 150 minutes). The median perfusion volume of lactated Ringer solution was 15,000 mL (range, 6,000 to 30,000 mL). The median traction time was 37.5 minutes (range, 30 to 105 minutes). None of the patients had postoperative complications develop. With a mean decrease of 0.84 +/- 0.68 mg/dL, only serum calcium levels were found to decrease significantly (P = .01). There was a mean decrease of 1.50 +/- 2.07 mEq/L in sodium concentrations (P = .06). Hip arthroscopy was associated with a mean postoperative decrease in creatinine and BUN concentrations of 0.05 +/- 0.06 mg/dL (P = .19) and 9.84 +/- 10.36 mg/dL (P = .13), respectively. Although the mean decrease in BUN concentration was important, this was not shown to be significant. No correlations were found between operating time, perfusion volume, and postoperative changes.

CONCLUSIONS

Lengthy therapeutic hip arthroscopy under high intra-articular pressure has only a minimal effect on electrolyte balance and renal function. We therefore conclude that performing routine preoperative and postoperative blood analysis of electrolyte concentrations and renal function is unnecessary.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Hip arthroscopy for labral pathology: prospective analysis with 10-year follow-up

PURPOSE

The purpose of this study was to investigate the results of arthroscopic treatment of acetabular labral tears (the most common indication for hip arthroscopy) in a consecutive series of patients with 10-year follow-up.

METHODS

Since 1993, all of our patients undergoing hip arthroscopy have been prospectively assessed by use of a modified Harris Hip Score preoperatively and postoperatively at 3, 12, 24, 60, and 120 months. Variables recorded include age, sex, diagnosis, duration of symptoms, onset of symptoms, center-edge angle, Workers' compensation status, and pending litigation. From a cohort of 52 procedures performed on 50 patients who had achieved 10-year follow-up, 29 patients (31 hips) were treated for a tear of the acetabular labrum and represent the substance of this study.

RESULTS

There was 100% follow-up, excluding 3 patients (5 hips) who died before their 10-year assessment. The mean age was 46 years (range, 17 to 84 years); there were 13 male and 13 female patients. The median Harris Hip Score improvement was 29 points (from 52 points preoperatively to 81 points postoperatively). Among 18 patients without arthritis, 15 (83%) continued to show substantial improvement (>or=18 points) at 10-year follow-up. Among 8 patients with associated arthritis, 7 (88%) were converted to total hip arthroplasty at a mean of 63 months. Two patients underwent repeat arthroscopy, which did not preclude a successful outcome at 10-year follow-up. There were no complications.

CONCLUSIONS

Selective debridement of symptomatic tears can result in favorable long-term results. The presence of clinical findings of arthritis at the time of the index procedure is a poor prognostic indicator, with uniformly poor results at 10 years.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement

PURPOSE

The purpose of this study was to compare the outcomes of arthroscopic labral debridement with those of labral refixation.

METHODS

We reviewed patients who underwent labral debridement during a period before the development of labral repair techniques. Patients with labral tears deemed repairable with our current arthroscopic technique were compared with patients who underwent labral refixation with a minimum 1 of year of follow-up. To better match the 2 groups, only patients with labral pathology caused by pincer-type or combined pincer- and cam-type femoroacetabular impingement were included. In the first 36 hips the labrum was debrided (group 1); in the next 39 hips the labrum underwent refixation (group 2). Outcomes were measured preoperatively and postoperatively with the modified Harris Hip Score (HHS), Short Form 12, and visual analog scale for pain. Preoperative and postoperative radiographs were obtained to evaluate bony resection (alpha angle) and osteoarthritis (Tönnis grade).

RESULTS

The mean age was 31 years in group 1, with a mean follow-up of 21.4 months, and 27 years in group 2, with a mean follow-up of 16.5 months. Preoperative subjective outcomes scores were not significantly different between groups. At the 1-year follow-up visit, subjective outcomes were significantly improved (P < .01) in both groups. HHSs were significantly better for the refixation group (94.3) compared with the debridement group (88.9) at 1 year (P = .029). At most recent follow-up, good to excellent results were noted in 66.7% of hips in the debridement group compared with 89.7% of hips in the refixation group (P < .01).

CONCLUSIONS

Although other variables could have influenced these outcomes, these preliminary results indicate that labral refixation resulted in better HHS outcomes and a greater percentage of good to excellent results compared with the results of labral debridement in an earlier cohort.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Outcomes following hip arthroscopy for femoroacetabular impingement with associated chondrolabral dysfunction: minimum two-year follow-up

Over an eight-month period we prospectively enrolled 122 patients who underwent arthroscopic surgery of the hip for femoroacetabular impingement and met the inclusion criteria for this study. Patients with bilateral hip arthroscopy, avascular necrosis and previous hip surgery were excluded. Ten patients refused to participate leaving 112 in the study. There were 62 women and 50 men. The mean age of the patients was 40.6 yrs (95% confidence interval (CI) 37.7 to 43.5). At arthroscopy, 23 patients underwent osteoplasty only for cam impingement, three underwent rim trimming only for pincer impingement, and 86 underwent both procedures for mixed-type impingement. The mean follow-up was 2.3 years (2.0 to 2.9). The mean modified Harris hip score (HHS) improved from 58 to 84 (mean difference = 24 (95% CI 19 to 28)) and the median patient satisfaction was 9 (1 to 10). Ten patients underwent total hip replacement at a mean of 16 months (8 to 26) after arthroscopy. The predictors of a better outcome were the pre-operative modified HHS (p = 0.018), joint space narrowing >or= 2 mm (p = 0.005), and repair of labral pathology instead of debridement (p = 0.032). Hip arthroscopy for femoroacetabular impingement, accompanied by suitable rehabilitation, gives a good short-term outcome and high patient satisfaction.

Safe angle for suture anchor insertion during acetabular labral repair

PURPOSE

The purpose of this study was to define a safe angle for suture anchor insertion during acetabular labral repair that will facilitate anchor placement within bone and prevent penetration into the hip joint.

METHODS

Nine acetabuli were harvested. Anatomic measurements were performed at the anterosuperior quadrant. Electronic calipers were used to measure acetabular bone. "Safe angle" measurements were obtained with suture anchor drills and a protractor. Comparisons between groups were calculated with a 1-way analysis of variance. The Tukey post-hoc analysis was completed for all significant analysis of variance results.

RESULTS

Labral insertion point distances and acetabular bone widths at the labral insertion did not statistically differ. Mean "danger angles" ranged from 17.0 degrees to 23.8 degrees. Safe angle measurements ranged from 20.1 degrees to 27.6 degrees.

CONCLUSIONS

The extracapsular labral insertion, located between 2.3 and 2.6 mm from the rim of the anterosuperior acetabulum, is offered as a starting point for insertion of anchors sized less than 3.0 mm. The danger angle and safe angle of anchor insertion serve as guidelines that may improve fixation in bone and lessen intra-articular penetration. A target angle of 10 degrees is recommended.

CLINICAL RELEVANCE

The danger angle and safe angle may be referenced intraoperatively, during imaging and suture anchor insertion, to assure anchor placement within bone and prevent intra-articular penetration. A target angle of 10 degrees is safe and easily remembered.

Differential diagnosis of pain around the hip joint

The differential diagnosis of hip pain is broad and includes intra-articular pathology, extra-articular pathology, and mimickers, including the joints of the pelvic ring. With the current advancements in hip arthroscopy, more patients are being evaluated for hip pain. In recent years, our understanding of the functional anatomy around the hip has improved. In addition, because of advancements in magnetic resonance imaging, the diagnosis of soft tissue causes of hip pain has improved. All of these advances have broadened the differential diagnosis of pain around the hip joint and improved the treatment of these problems. In this review, we discuss the causes of intra-articular hip pain that can be addressed arthroscopically: labral tears, loose bodies, femoroacetabular impingement, capsular laxity, tears of the ligamentum teres, and chondral damage. Extra-articular diagnoses that can be managed arthroscopically are also discussed, including: iliopsoas tendonitis, "internal" snapping hip, "external" snapping hip, iliotibial band and greater trochanteric bursitis, and gluteal tendon injury. Finally, we discuss extra-articular causes of hip pain that are often managed nonoperatively or in an open fashion: femoral neck stress fracture, adductor strain, piriformis syndrome, sacroiliac joint pain, athletic pubalgia, "sports hernia," "Gilmore's groin," and osteitis pubis.

Postoperative analgesia for hip arthroscopy: combined L1 and L2 paravertebral blocks

Two patients are presented who underwent successful combined L1 and L2 paravertebral blocks as part of an anesthetic technique for hip arthroscopy.

Beginning hip arthroscopy: indications, positioning, portals, basic techniques, and complications

Hip arthroscopy is becoming increasingly popular for the diagnosis and treatment of hip pathology, and the indications continue to evolve. The two most common approaches are the supine and lateral decubitus position. Both approaches can be performed effectively; however, each approach has its own benefits and drawbacks. In this review we will describe the indications for hip arthroscopy, the pros and cons of each approach, and the necessary equipment, portals, portal placement, commercially available distraction devices, and complications.

Radiologic and intraoperative findings in revision hip arthroscopy

PURPOSE

The purpose of this study was to identify possible causes of failure of hip arthroscopy by reviewing the intraoperative and radiologic findings in a series of patients requiring revision hip arthroscopy.

METHODS

We retrospectively reviewed 24 revision hip arthroscopy cases performed in 23 patients (14 female and 9 male; mean age, 33.6 years; 1 bilateral). The review included indications for surgery, intraoperative findings, and arthroscopic interventions for both the primary and revision surgeries. Imaging studies, including radiography, magnetic resonance imaging, and 3-dimensionally reconstructed computed tomography scans, were analyzed for the presence of preoperative bony impingement lesions (e.g., femoral head-neck junction "cam" lesions or anterosuperior acetabular "pincer" lesions).

RESULTS

The mean interval between previous hip arthroscopy and recurrence of symptoms was 6.1 months. In 13 of 24 cases (54%), patients had no significant improvement at any point after the primary hip arthroscopy. The mean interval between the previous hip arthroscopy and revision surgery was 25.6 months. Unaddressed or undertreated bony impingement lesions were found in 19 of 24 cases (79%) and were identified on imaging studies before revision hip arthroscopy. A tight psoas tendon and corresponding labral impingement lesion were identified by arthroscopic visualization in 7 of 24 cases, for which partial psoas tendon release was performed. Eight cases of failed labral repair were addressed with labral debridement and removal of suture material. Of these 8 cases, 6 also had bony impingement, which was also addressed at the time of the revision surgery.

CONCLUSIONS

Failure to address bony impingement lesions of the hip and a tight psoas tendon are key factors in unsuccessful hip arthroscopy and may require revision surgery. Furthermore, failure of labral repairs may be the result of unrecognized bony impingement at the time of initial surgery.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

[Surgical treatment of hip osteoarthritis: hpdete on hip arthroscopy]

Arthroscopic surgery of the hip is a routine procedure in an increasing number of institutions around the world. Indications for this procedure increase as more experience is developed. Thanks to hip arthroscopy some intraarticular lesions like labral or ligamentum teres tears and cartilage lesions have been recognized. All of these have the potential to develop hip osteoarthritis. Open techniques for the treatment of femoroacetabular impingement have been transformed to arthroscopic techniques. Femoroacetabular impingement has the potential to cause hip osteoarthritis. The role of hip arthroscopy in the treatment of formally established hip osteoarthritis is limited and has better results in young patients with early degenerative changes.

Arthroscopic repair of the acetabular labrum: a histologic assessment of healing in an ovine model

PURPOSE

Recently, arthroscopic repair has been advocated for the treatment of labral tears. The purpose of this study was to document the histologic healing process in an arthroscopically repaired acetabular-labral detachment in an ovine model.

METHODS

A total of 10 skeletally mature female sheep underwent unilateral arthroscopic labral repair. A 1.5-cm-long incision was made at the junction of the labrum and acetabulum. The labral detachment was then repaired arthroscopically with a single suture anchor. Postoperatively, the animals were confined to small indoor pens, and no form of immobilization was used. After 12 weeks, the animals were killed and the labral repair evaluated via routine histology. Normal labra from 3 nonoperative animals were also processed for histology.

RESULTS

The acetabular labrum of the sheep is an avascular, fibrocartilaginous structure similar in anatomic design to that of human beings. All arthroscopically repaired labra appeared stable and grossly healed at 12 weeks. Histologically, labral healing appeared to occur via fibrovascular scar tissue originating from the joint capsule or the exposed bony attachment of the labrum (or both). However, the labral healing was incomplete in all specimens, with a shallow, superficial cleft remaining at the junction of the labrum and the articular surface of the acetabulum.

CONCLUSIONS

Arthroscopically repaired acetabular-labral lesions in sheep are capable of healing via fibrovascular repair tissue or direct reattachment via new bone formation (or both).

CLINICAL RELEVANCE

The ability of labral detachments to heal in this animal model provides the rationale for additional investigations into the clinical efficacy of arthroscopic labral repair in human beings.