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

Association Between Severity of Chondrolabral Junction Breakdown and Functional Outcomes After Hip Arthroscopy for Acetabular Labral Tears

BACKGROUND

Despite focus on surgical preservation of the chondrolabral junction (CLJ), the transition zone between the acetabular cartilage and labrum, the association between severity of CLJ breakdown and functional outcomes after hip arthroscopy remains unexplored.

PURPOSE

To assess the influence of CLJ breakdown on patient-reported outcome measures (PROMs) at a 24-month follow-up after hip arthroscopy for symptomatic labral tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of prospectively collected data was conducted to identify patients ≥18 years of age with a minimum 24-month follow-up who underwent hip arthroscopy by a single surgeon for the treatment of symptomatic labral tears secondary to femoroacetabular impingement. The Beck classification of transition zone cartilage was used to grade CLJ damage; patients with grades 0 to 2 were stratified into the mild CLJ damage cohort, and those with grades 3 and 4 were stratified into the severe CLJ damage cohort. PROMs were collected at baseline and at 3, 6, 12 months, and annually thereafter postoperatively. Linear mixed-effects models were used to compare PROMs. Rates of achieving clinically meaningful thresholds and subsequent surgery rates were also compared.

RESULTS

In total, 198 patients met the inclusion criteria, with a mean follow-up of 3.54 ± 1.26 years. A total of 95 patients with severe CLJ damage (mean age, 34.9 ± 10.5 years) were compared with 103 patients with mild CLJ damage (mean age, 38.2 ± 11.9 years). Hip Outcome Score-Activities of Daily Living (HOS-ADL), Non-Arthritic Hip Score (NAHS), and visual analog score for pain were inferior in the severe CLJ group at enrollment and all follow-up time points (P≤ .05). However, patients with severe CLJ breakdown exhibited greater improvements in HOS-ADL and NAHS at the 24-month follow-up and achieved clinically meaningful thresholds at equivalent rates to patients with mild CLJ breakdown. Subsequent surgery rates were 6.8% and 12.6% in patients with mild versus severe CLJ damage, respectively (P = .250).

CONCLUSION

Severe CLJ breakdown is associated with increased pain and decreased functional level preoperatively and up to 24 months after hip arthroscopy. Despite this, patients with severe CLJ breakdown experienced greater improvements in functional outcomes at a 24-month follow-up and achieved clinical thresholds at similar rates to patients with mild CLJ damage. Thus, while worse baseline pain and functional levels may indicate severe CLJ breakdown, these patients still benefit substantially from hip arthroscopy.

Association Between Chondrolabral Junction Breakdown and Conversion to Total Hip Arthroplasty After Hip Arthroscopy for Symptomatic Labral Tears: Minimum 8-Year Follow-up

BACKGROUND

Arthroscopic treatment of femoroacetabular impingement (FAI) and symptomatic labral tears confers short- to midterm benefits, yet further long-term evidence is needed. Moreover, despite the physiological and biomechanical significance of the chondrolabral junction (CLJ), the clinical implications of damage to this transition zone remain understudied.

PURPOSE

To (1) report minimum 8-year survivorship and patient-reported outcome measures after hip arthroscopy for FAI and (2) characterize associations between outcomes and patient characteristics (age, body mass index, sex), pathological parameters (Tönnis angle, alpha angle, type of FAI, CLJ breakdown), and procedures performed (labral management, FAI treatment, microfracture).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This retrospective cohort study included patients who underwent primary hip arthroscopy for symptomatic labral tears secondary to FAI by a single surgeon between 2002 and 2013. All patients were ≥18 years of age with minimum 8-year follow-up and available preoperative radiographs. The primary outcome was conversion to total hip arthroplasty (THA), and secondary outcomes included revision arthroscopy, patient-reported outcome measures, and patient satisfaction. CLJ breakdown was assessed using the Beck classification. Kaplan-Meier estimates and weighted Cox regression were used to estimate 10-year survivorship (no conversion to THA) and identify risk factors associated with THA conversion.

RESULTS

In this study of 174 hips (50.6% female; mean age, 37.8 ± 11.2 years) with mean follow-up of 11.1 ± 2.5 years, the 10-year survivorship rate was 81.6% (95% CI, 75.9%-87.7%). Conversion to THA occurred at a mean 4.7 ± 3.8 years postoperatively. Unadjusted analyses revealed several variables significantly associated with THA conversion, including older age; higher body mass index; higher Tönnis grade; labral debridement; and advanced breakdown of the CLJ, labrum, or articular cartilage. Survivorship at 10 years was inferior in patients exhibiting severe (43.6%; 95% CI, 31.9%-59.7%) versus mild (97.9%; 95% CI, 95.1%-100%) breakdown of the CLJ (P < .001). Multivariable analysis identified worsening CLJ breakdown (weighted hazard ratio per 1-unit increase, 6.41; 95% CI, 3.11-13.24), older age (1.09; 95% CI, 1.04-1.14), and higher Tönnis grade (4.59; 95% CI, 2.13-9.90) as independent negative prognosticators (P < .001 for all).

CONCLUSION

Although most patients achieved favorable minimum 8-year outcomes, several pre- and intraoperative factors were associated with THA conversion; of these, worse CLJ breakdown, higher Tönnis grade, and older age were the strongest predictors.

Fixation strength in arthroscopic labral repair of the hip: A head-to-head comparison of the biomechanical performance of a biocompatible vs. all-suture anchor in the setting of acetabuloplasty

Much is known about the biomechanical performance of various types of suture anchors commonly used for labral fixation in the shoulder; however, similar studies in the hip are less common. We sought to compare all-suture and polyether ether ketone small-diameter anchors in the setting of labral repair during hip arthroscopy, with and without acetabuloplasty. We hypothesized that the biomechanical properties of the all-suture group when compared to polyether ether ketone anchors would be similar amongst native acetabula and significantly less following acetabuloplasty and that pullout forces would be reduced in the anterior and inferior regions of the acetabulum compared to the superior region. Bone density was measured in nine matched pairs of fresh-frozen cadaveric acetabula in the superior, anterosuperior, and anterior regions. Acetabuloplasty was performed in all three regions, while the contralateral acetabulum was left in situ as a control. Suture anchors were placed such that one each of two different types was placed within each region. Specimens were tested in cyclic fatigue and loaded to failure. The all-suture group had significantly higher cyclic displacement compared to the polyether ether ketone, but there was no significant difference in ultimate load, regardless of acetabuloplasty. Amongst all non-resected specimens, the lowest bone density was observed consistently in the inferior region. Our results indicate that, with or without acetabuloplasty, a small-diameter polyether ether ketone anchor appears to be more stable than an all-suture anchor, which needs to be set first.

Labral Reconstruction via Capsular Augmentation Maintains Perfusion to the Acetabular Labrum and Locally Transferred Autograft: An in Vivo Laser Doppler Flowmetry Analysis

Background

The purpose of the present study was to examine the effects of arthroscopic labral repair with capsular augmentation on blood flow in vivo with use of laser Doppler flowmetry (LDF) to measure microvascular perfusion of the labrum and autograft tissue.

Methods

The present prospective case series included patients ≥18 years old who underwent arthroscopic acetabular labral repair with capsular augmentation; all procedures were performed by a single surgeon between 2018 and 2022. The LDF probe measured microvascular blood flow flux within 1 mm3 of the surrounding labral and capsular tissue of interest. Mean baseline measurements of flux were compared with readings immediately following capsular elevation and after completing labral augmentation. Blood flux changes were expressed as the percent change from the baseline measurements.

Results

The present study included 41 patients (24 men [58.5%] and 17 women [41.5%]) with a mean age (and standard deviation) of 31.3 ± 8.4 years, a mean BMI of 24.6 ± 3.4 kg/m2, a mean lateral center-edge of angle 35.3° ± 4.9°, a mean Tönnis angle of 5.8° ± 5.8°, and a mean arterial pressure of 93.7 ± 10.9 mm Hg. Following capsular elevation, the mean percent change in capsular blood flow flux was significantly different from baseline (-9.24% [95% confidence interval (CI), -18.1% to -0.04%]; p < 0.001). Following labral augmentation, the mean percent change in labral blood flow flux was significantly different from baseline both medially (-22.3% [95% CI, -32.7% to -11.9%]; p < 0.001) and laterally (-32.5% [95% CI, -41.5% to -23.6%]; p = 0.041). There was no significant difference between the changes in medial and lateral perfusion following repair (p = 0.136).

Conclusions

Labral repair with capsular augmentation sustains a reduced blood flow to the native labrum and capsular tissue at the time of fixation. The biological importance of this reduction is unknown, but these findings may serve as a benchmark for other labral preservation techniques and support future correlations with clinical outcomes.

Level of Evidence

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

Surgeon-Specific Traction Time During Hip Arthroscopy for Primary Labral Repair Can Continue to Decrease After a Substantial Number of Surgeries

PURPOSE

The purpose of this study was to evaluate the total traction time and traction time as a function of anchors placed (TTAP) for primary labral repair in patients undergoing hip arthroscopy by a single surgeon.

METHODS

Patients were included if they received a primary labral repair with or without acetabuloplasty, chondroplasty, or ligamentum teres debridement as part of the treatment for femoroacetabular impingement (FAI). Patients were excluded if they had a previous ipsilateral hip surgery, prior hip conditions, Tönnis grade >1, open procedures, microfracture, ligamentum teres reconstruction, or labral reconstruction. TTAP was calculated by dividing total traction time by the number of anchors placed.

RESULTS

2,350 hips met the inclusion criteria. The mean age and BMI in this cohort were 34.22 years and 25.72 kg/m², respectively. A total traction time of 60 minutes was first achieved after 268 cases. Mean overall total traction time was 58.16 minutes (95% CI [57.35, 58.97]) and mean TTAP was 16.24 minutes (95% CI [15.93,16.55]) after 2,350 cases. Total traction time plateaued after 374 cases at 55.92 minutes, while TTAP plateaued after 487 cases at 14.93 minutes.

CONCLUSION

Surgeons who introduce hip arthroscopy into their practice can expect to see improvements in traction time during the first 500 surgeries performed, as total traction time plateaued after 374 cases and TTAP plateaued after 487 cases.

LEVEL OF EVIDENCE

IV: case series.

Arthroscopic Debridement Versus Refixation of the Acetabular Labrum Associated With Femoroacetabular Impingement: Updated Mean 7-Year Follow-up

BACKGROUND

Short- and midterm follow-up studies suggest that arthroscopic labral refixation/preservation leads to superior outcomes compared with labral excision/debridement.

PURPOSE

To update the previous early (16 months) and midterm (mean, 42 months) follow-up of this cohort, which reported better patient-reported outcome measures and lower failure rates in the repair/refixation group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The authors identified patients who underwent labral debridement/focal labral excision during a period before the development of labral repair techniques. A consecutive group of patients within the labral debridement group thought to be repairable with the authors' current arthroscopic techniques were compared with a group of consecutive patients who underwent labral repair/refixation. In 46 hips, the labrum was focally excised/debrided consistent with pincer- or combined pincer- and cam-type impingement; in 54 hips, the labrum was repaired/refixed. Subjective outcomes were measured with the modified Harris Hip Score (mHHS), 12-Item Short Form Health Survey (SF-12), and visual analog scale (VAS) for pain preoperatively and postoperatively.

RESULTS

The mean age was 34.0 years in the debridement group and 28.3 years in the repair/refixation group, with a mean follow-up of 7.3 years (range, 2-13.6 years). At the mean follow-up of 7.3 years, subjective outcomes were significantly improved (P < .01) for both groups compared with preoperative scores. The mHHS (P = .008), SF-12 score (P = .012), and VAS pain score (P = .002) were all significantly better for the repair/refixation group compared with the debridement group. Although most recent outcomes for both groups fell slightly at the mean follow-up of 7.3 years in comparison with the 16-month and 3.5-year follow-ups, these differences were not significant. However, the failure rate in the debridement group did get significantly worse (P = .014). Good to excellent results were 47.7% in the debridement group and 86.3% in the refixation group (P < .001), and failure rates were 30.4% (debridement) and 13% (refixation) (P = .033). There were 4 revisions in the debridement group and 3 revisions in the refixation group.

CONCLUSION

Longer term, >7-year follow-up comparing focal labral excision/debridement with repair/refixation revealed better patient-reported outcomes and lower failure rates in the labral repair/refixation cohort. Additionally, despite an absolute decrease in patient-related outcome scoring and number of good/excellent results in both groups compared with the 3.5-year report, there was a significantly greater increase in failure rates over time for the excision/debridement group with better maintenance of good to excellent results in the repair/refixation group.

Prehabilitation and Rehabilitation Program for Patients Undergoing Arthroscopic Acetabular Labral Repair: A Comprehensive 5-Phase Patient-Guided Program

Background:

Many of the current rehabilitation programs for patients undergoing hip arthroscopy fail to consider the progression of soft tissue healing and inflammation that can be heightened due to aggressive therapy to the operative hip in the immediate postoperative period.

Hypothesis:

It was hypothesized that introducing conservative physical therapy (PT) preoperatively along with a slow progression to return to activity using a structured, patient-guided postoperative program would improve patient outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

The authors conducted a retrospective review of patients who received a hip arthroscopy, were at least 18 years old, and who had completed the following patient-reported outcomes (PROs) at 1-year follow-up: modified Harris Hip Score (mHHS), Hip Outcome Score, Nonarthritic Hip Score, International Hip Outcome Tool-33, and Lower Extremity Functional Scale. Patients who underwent previous surgery on the ipsilateral hip and those with cartilage erosion down to exposed subchondral bone (Outerbridge grade 4) were excluded. Paired-samples t tests were used to compare the change in PRO scores at 3-month, 6-month, and 1-year follow-up, and the percentage of patients who achieved minimal clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds on the mHHS were stratified according to their Outerbridge grade (0-3).

Results:

Overall, 202 patients (53% female, 47% male) were included in the analysis. Significant improvement was seen from 3 to 6 months on all PRO measures and from 6 months to 1 year on all but the mHHS (P < .05 for all except the mHHS). A significantly smaller percentage of patients with Outerbridge grade 3 cartilage damage achieved the MCID and SCB on the mHHS compared with those with grade 0, both at 6 months (grade 3 vs 0: 20% vs 63.2% [MCID]; 18.0% vs 52.6% [SCB]; both P = .03) and 1 year (grade 3 vs 0: 22.0% vs 57.9% [MCID]; 14.0% vs 52.6% [SCB]; both P < .05).

Conclusion:

A structured, patient-guided PT protocol after arthroscopic acetabular labral repair can significantly improve postoperative outcomes.

Comparison Between Hip Arthroscopic Surgery and Periacetabular Osteotomy for the Treatment of Patients With Borderline Developmental Dysplasia of the Hip: A Systematic Review

Background:

The treatment for borderline developmental dysplasia of the hip (BDDH) has historically been arthroscopic surgery or periacetabular osteotomy (PAO). As orthopaedic surgery is constantly evolving, a lack of comparison of outcomes for these 2 treatment methods could potentially be stalling the progression of treatment for patients with BDDH.

Purpose:

To evaluate the existing literature on patient characteristics, procedures, clinical outcomes, and failure rates for patients with BDDH and to determine whether PAO or hip arthroscopic surgery is a better treatment method for patients with BDDH.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Studies included were found using the following search words: “hip” and “borderline dysplasia,” “osteotomy” or “arthroscopy,” and “outcome” or “procedure.” Articles were included if they detailed participants of all sexes and ages, reported on isolated hips, and had patients diagnosed with BDDH.

Results:

A search was conducted across 3 databases, resulting in 469 articles for consideration, from which 12 total studies (10 on arthroscopic surgery and 2 on PAO) were chosen for a review. There were 6 studies that included patients with a lateral center-edge angle of 18° to 25°, while the remainder included patients with a lateral center-edge angle of 20° to 25°. All the studies reviewing arthroscopic surgery reported concomitant/accessory procedures, while the articles on the topic of PAO did not. It was determined that, whether treated using arthroscopic surgery or PAO, outcomes improved across all patient-reported outcome measures. Revision surgery was also common in both procedures.

Conclusion:

There is a lack of consensus in the literature on the best treatment option for patients with BDDH. Preoperative patient characteristics and concomitant injuries should be considered when evaluating which surgical procedure will result in the most favorable outcomes.

Editorial Commentary: Suture Anchor Fixation Eliminates the Wave Sign and Improves Outcomes for Hip Labrochondral Dysfunction. Do Not Equate Hip Labral Pathology With Shoulder Labral Tears

During hip arthroscopy, when a wave sign is encountered, it is a sign of labrochondral dysfunction, just like a traditional labral tear. Suture anchor fixation to the labrum can eliminate the wave sign and improve patient outcomes. Readers are urged not to equate hip labral pathology with shoulder labral tears, which have different pathomechanics, and subsequently may have different morphological characteristics.

Allocation of Anchors During Labral Repair: A Multicenter Cohort Analysis of Labral Treatment in Hip Arthroscopy

Background:

While previous studies have established several techniques for suture anchor repair of the acetabular labrum to bone during arthroscopic surgery, the current literature lacks evidence defining the appropriate number of suture anchors required to effectively restore the function of the labral tissue.

Purpose/Hypothesis:

To define the location and size of labral tears identified during hip arthroscopy for acetabular labral treatment in a large multicenter cohort. The secondary purpose was to differentiate the number of anchors used during arthroscopic labral repair. The hypothesis was that the location and size of the labral tear as well as the number of anchors identified would provide a range of fixation density per acetabular region and fixation method to be used as a guide in performing arthroscopic repair.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We used a multicenter registry of prospectively collected hip arthroscopy cases to find patients who underwent arthroscopic labral repair by 1 of 7 orthopaedic surgeons between January 2015 and January 2017. The tear location and number of anchors used during repair were described using the clockface method, where 3 o’clock denoted the anterior extent of the tear and 9 o’clock the posterior extent, regardless of sidedness (left or right). Tear size was denoted as the number of “hours” spanned per clockface arc. Chi-square and univariate analyses of variance were performed to evaluate the data for both the entire group and among surgical centers.

Results:

A total of 1978 hips underwent arthroscopic treatment of the acetabular labrum; the most common tear size had a 3-hour span (n = 820; 41.5%). Of these hips, 1645 received labral repair, with most common repair location at the 12- to 3-o’clock position (n = 537; 32.6%). The surgeons varied in number of anchors per repair according to labral size (P < .001 for all), using 1 to 1.6 anchors for 1-hour tears, 1.7 to 2.4 anchors for 2-hour tears, 2.1 to 3.2 anchors for 3-hour tears, and 2.2 to 4.1 for 4-hour tears.

Conclusion:

Variation existed in the number of anchor implants per tear size. When labral repair involved a mean clockface arc >2 hours, at least 2 anchor points were fixated.

[Research progress in arthroscopic treatment of acetabular labrum injury]

Objective

To review the surgical methods of arthroscopy in the treatment of acetabular labrum injury, and to provide reference for clinical treatment.

Methods

The literature about the surgical methods and clinical results of hip arthroscopy in the treatment of acetabular labrum injury was reviewed and analyzed.

Results

In the early stages of hip arthroscopy, the removal of the torn labrum is the primary treatment option. The current principles of treatment are based on the specific circumstances of a torn labrum, including acetabular labrum debridement, acetabular labrum repair, acetabular labrum reconstruction, and acetabular labrum augmentation.

Conclusion

Hip arthroscopy has become the preferred technique for the treatment of acetabular labrum injury. Labral repair is still the first choice, and labral reconstruction is used when acetabular labrum injury cannot be repaired.

Expression profile of matrix metalloproteinases in the labrum of femoroacetabular impingement

Aims

Femoroacetabular impingement (FAI) is a potential cause of hip osteoarthritis (OA). The purpose of this study was to investigate the expression profile of matrix metalloproteinases (MMPs) in the labral tissue with FAI pathology.

Methods

In this study, labral tissues were collected from four FAI patients arthroscopically and from three normal hips of deceased donors. Proteins extracted from the FAI and normal labrums were separately applied for MMP array to screen the expression of seven MMPs and three tissue inhibitors of metalloproteinases (TIMPs). The expression of individual MMPs and TIMPs was quantified by densitometry and compared between the FAI and normal labral groups. The expression of selected MMPs and TIMPs was validated and localized in the labrum with immunohistochemistry.

Results

On MMP arrays, most of the targeted MMPs and TIMPs were detected in the FAI and normal labral proteins. After data normalization, in comparison with the normal labral proteins, expression of MMP-1 and MMP-2 in the FAI group was increased and expression of TIMP-1 reduced. The histology of the FAI labrum showed disorderly cell distribution and altered composition of thick and thin collagen fibres. The labral cells expressing MMP-1 and MMP-2 were localized and their percentages were increased in the FAI labrum. Immunohistochemistry confirmed that the percentage of TIMP-1 positive cells was reduced in the FAI labrum.

Conclusion

This study established an expression profile of MMPs and TIMPs in the FAI labrum. The increased expression of MMP-1 and MMP-2 and reduced expression of TIMP-1 in the FAI labrum are indicative of a pathogenic role of FAI in hip OA development.

Cite this article:Bone Joint Res. 2020;9(4):173–181.

Translational relevance of the goat as a preclinical model of the human labrum and chondrolabral junction-histological study

The purpose of this study was to evaluate the histologic features of the caprine labrum, with emphasis on the chondrolabral junction, with the goal of informing the feasibility of the goat as an animal model. The left hip joint of six adolescent Spanish goats (Capra pyrenaica) was harvested and subjected to anatomical and histological assessments. Human acetabular and femoral head samples, collected during total hip arthroplasty, served as comparison samples. The caprine labrum was found to consist of mostly type I collagen with uniform crimp, with an average crimp length of 20.8 µm. Upon histological assessment, acetabular articular chondrocytes were found to express substance-P, especially near or in the chondrolabral junction. And the majority of nonvascular cells expressed α-smooth muscle actin (SMA), with no notable elastin and laminin expression. Human labrum demonstrated similar staining patterns. Overall, the goat hip was found to be homologous to the human hip, demonstrating potential as a useful animal model for future studies. This is the first report of a crimped collagen structure in the labrum. Crimped type I collagen at the chondrolabral junction imparts an extension-recovery property which allows for toleration of stress without permanent deformation, underlying the importance of its preservation during surgery. The high expression of substance-P reflects the degree to which the labrum is innervated. Finally, the expression of α-SMA with contractile characteristics could indicate the potential for chondrocyte (i.e., myochondrocytes) modeling of the extracellular matrix. Statement of Clinical Significance: Establishment of a large animal model and deeper knowledge of the histological composition of the hip joint will enhance our study of the acetabular labrum, including repair techniques. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1070-1080, 2020.

Biomechanical comparison of knotless vs. knotted suture anchors in the acetabular rim with respect to bone density

BACKGROUND

Acetabular labral tears are managed with suture anchors providing good clinical outcomes. Knotless anchors are easier to use and have a quicker insertion time compared to knotted anchors. The purpose of this study was to compare the biomechanical behavior of two different anchor designs (knotted vs. knotless) in ultimate load testing in correlation with bone density in the acetabular rim.

METHODS

Eighteen knotted Bio-FASTak and seventeen knotless PushLock anchors (both: Arthrex Inc., Naples, FL, USA) were inserted in the rims of two human acetabula, with known bone density distribution. The anchors were subjected to load-to-failure tests. Anchors were additionally tested in solid polyurethane foam with defined densities.

FINDINGS

The Bio-FASTak group showed higher survival rates at 1, 2, and 3 mm displacement and was able to withstand significantly higher loads at 3 mm displacement (p = 0.031). There was no statistically significant difference in stiffness (p = 0.087), yield- (p = 0.190), and ultimate load (p = 0.222) between the two groups. Only the PushLock group showed correlation between bone volume over total volume (BV/TV) and stiffness (R = 0.750, p = 0.086) and between BV/TV and yield load (R = 0.838, p = 0.037). Experiments on solid polyurethane foam confirmed the correlation between the mechanical properties and tissue density for the same anchor.

INTERPRETATION

PushLock shows similar biomechanical properties to the Bio-FASTak, but eliminates knot tying and potentially abrasive knots. In addition, biomechanical properties of the PushLock are governed by local bone density.

The clinical outcome of chondrolabral-preserving arthroscopic acetabuloplasty for pincer- or mixed-type femoroacetabular impingement: A systematic review

While preservation and repair of the acetabular labrum are increasingly being recognized as important goals in hip arthroscopy, controversies still exist regarding the clinical outcome of arthroscopic acetabuloplasty with chondrolabral preservation. A systematic review was conducted and implemented by two independent reviewers, who used the MEDLINE/PubMed database and the Cochrane Database of Systematic Reviews for their search. These databases were queried with the terms "arthroscopic acetabuloplasty" and "chondrolabral preservation" and "arthroscopic acetabular recession." From the 55 initial studies the reviewers finally chose and assessed five clinical studies which were eligible to their inclusion-exclusion criteria. The reviewed studies included in total 444 patients, mainly young, between 30 and 40 years old. The follow-up evaluation varied between 24 and 41 months, while all studies utilized at least a 24-month final end-point assessment. All five studies illustrated improved outcome with the use of chondrolabral preservation acetabuloplasty without labral detachment. The rate of complications was very low. The different techniques of arthroscopic acetabuloplasty combined with chondrolabral preservation illustrated encouraging results in patients suffering from pincer-type or mixed-type FAI. However, the available clinical evidence was limited and insufficient to establish any superiority of these techniques over the traditional labral detachment and sequential reattachment. In relation to the optimal treatment of FAI without isolated CAM, further research of higher quality is recommended to be conducted in order to lead to definitive conclusions.

Labral Augmentation with Native Tissue Preservation with a 7.5-Year Follow-up: A Case Report

CASE

Arthroscopic labral repair has resulted in excellent functional outcomes. However, extensive labral damage or diminutive size of the labrum may preclude a repair. In these cases, labral augmentation serves as an operative treatment option. We report the case of a labral augmentation with 7.5 years of follow-up, including intraoperative reexamination, which highlights the ability of an iliotibial band autograft to incorporate with the native labrum.

CONCLUSION

When indicated in an appropriate patient, labral augmentation with an iliotibial band autograft is an established technique that can result in an excellent outcome.

Acetabular Subchondral and Cortical Perforation During Labral Repair With Suture Anchors: Influence of Portal Location, Curved Versus Straight Drill Guides, and Drill Starting Point

PURPOSE

To evaluate the impact of the portal used for drilling, the position of the drill guide on the acetabular rim, and the use of straight versus curved drill guides on drill perforation of the acetabular subchondral bone and the outer cortex of the acetabulum.

METHODS

Sixty acetabular models were marked at the 3-, 2-, 1-, 12-, and 11-o'clock positions. Simulated anterior, anterolateral, and distal anterolateral accessory (DALA) portals were created. Twelve groups of 5 acetabula were drilled at each clock-face position using all combinations of variables.

RESULTS

A total of 38 of 300 drillings (12.7%) perforated the subchondral bone, and 45 of 300 (15%) breached the outer cortex. Drilling from the anterior, anterolateral, and DALA portals perforated the acetabular subchondral bone on 21 of 100 attempts (21%), 17 of 100 attempts (17%), and 0 of 100 attempts (0%), respectively (P < .001), and perforated the outer acetabular cortex on 36 of 100 attempts (36%), 1 of 100 attempts (1%), and 8 of 100 attempts (8%), respectively (P < .001). The use of a curved or straight drill guide did not make a statistically significant difference. Drilling with a starting point on the acetabular rim perforated the acetabular subchondral bone on 29 of 150 attempts (19.3%) compared with 9 of 150 attempts (6%) when the starting point was 2 mm removed from the acetabular rim (P < .001).

CONCLUSIONS

The use of the DALA portal and a drill starting point slightly off the acetabular rim was associated with the lowest rate of acetabular subchondral perforation and is recommended to reduce the risk of iatrogenic chondral injury.

CLINICAL RELEVANCE

Iatrogenic chondral injury is a relatively common complication of hip arthroscopy. Increased awareness of factors associated with drill perforation during suture anchor placement can help surgeons mitigate this risk.

Arthroscopic Acetabular Labral Repair Using the Q-FIX Suture Anchor

The goal of acetabular labral repair is to preserve/restore labral function. Maintaining labral function necessitates recreating the labrum's anatomy, especially avoiding a nonanatomic repair of the labrum to the acetabular rim. The purpose of this report is to detail the technique of acetabular labral repair using this Q-FIX all-suture anchor.

Preserving the chondrolabral junction reduces the rate of capsular adhesions

The operative treatment of pincer-type femoroacetabular impingement (FAI) has become an increasingly more common procedure. Classically, the labrum is incised at the chondrolabral junction (CLJ), or a concurrent tear is extended to allow access to the acetabular rim facilitating acetabuloplasty. The labrum is subsequently repaired using suture anchors. More recently, acetabuloplasty has been performed without incising the labrum and negating the need to use suture anchors. The aim of this study is to determine whether preserving the CLJ reduces the incidence of revision hip arthroscopy for the treatment of capsulolabral adhesions. This retrospective study compared two cohorts of patients undergoing hip arthroscopy for pincer-type FAI from August 2002 to April 2015. The groups analysed were patients undergoing acetabuloplasty with labral repair (LR) and those with no labral repair (NLR). The revision rates and causes for revision were compared using the χ² analysis. There were 1010 cases in total. Acetabuloplasty with LR was performed in 546 hips (519 patients), while acetabuloplasty with NLR was performed in 464 hips (431 patients). In the LR group, there were 54 (9.9%) revisions, 25 (46%) of which were due to capsulolabral adhesions. The NLR group had 36 (7.8%) revisions with six (17%) due to capsulolabral adhesions. Preserving the CLJ, thereby avoiding the need for drilling and the insertion of suture anchors, when performing an acetabuloplasty for pincer-type FAI, significantly reduces the rate of symptomatic adhesions requiring revision arthroscopy.

Femoral head fracture in an adult patient with isolated posterior labrum avulsion recognized through the 'fleck' sign: technical tips

Femoral head fractures in adults are known to be frequently associated with femoral neck fractures, acetabular fractures and sciatic nerve neurapraxia. Here, we report for the first time in the English medical literature the case of a 30-year-old patient having a Pipkin Type II comminuted femoral head fracture associated to an isolated acetabular labral osteochondral avulsion. This entity was diagnosed preoperatively through the presence of the acetabular ‘fleck’ sign recently described in adolescents with hip dislocation. This was of paramount importance knowing the key role of the acetabular labrum in physiological hip functioning. Therefore, a high index of suspicion of complete posterior acetabular labrum avulsion should be raised in front of a hip computed tomography scan showing the acetabular fleck sign even in an adult patient. This finding is important in posing the surgical indication and in completing the preoperative surgical planning in cases of femoral head fractures and dislocations.

Arthroscopic Acetabular Labral Repair in Patients Over the Age of 60 Years: A Matched Case-Control Study

PURPOSE

To report the results of labral repair in a population of patients older than 60 years and compare these with a matched population of younger adults.

METHODS

We compared 21 consecutive patients older than 60 years undergoing labral repair with minimum 1-year follow-up with a contemporaneous group of 21 patients aged 18 to 55 years matched for sex, degree of chondral damage, and associated femoroacetabular impingement or dysplasia.

RESULTS

Follow-up averaged 18.9 months (range, 12-24 months). The average age in the study group was 63.2 years (range, 61-71 years), and 20 patients had femoroacetabular impingement whereas 1 had dysplasia. Of these patients, 19 had acetabular articular damage (grade IV in 2, grade III in 11, grade II in 5, and grade I in 1) and 6 had femoral changes (grade IV in 1 and grade III in 5). The average age in the control group was 35.8 years (range, 20-54 years). We found average improvements of 28.1 points for the modified Harris Hip Score and 37.5 points for the International Hip Outcome Tool score within the study group and 21.2 points for the modified Harris Hip Score and 37.1 points for the International Hip Outcome Tool score within the control group. No statistically significant difference between the 2 groups was noted in the amount of improvement, with statistically and clinically significant improvements noted in both. Two study group patients underwent total hip arthroplasty (THA) at an average of 10 months, with 1 control group THA at 11 months. All 3 patients with conversion to THA had combined grade IV acetabular and grade III femoral damage. No repeated arthroscopies were performed and no complications occurred in either group.

CONCLUSIONS

Patients older than 60 years can benefit from arthroscopic labral repair with improved outcomes, a modest rate of conversion to THA, and a small risk of complications. The results are comparable to those of younger adults. Combined bipolar grade IV and grade III articular damage may be a harbinger of conversion to THA regardless of age.

LEVEL OF EVIDENCE

Level III, comparative therapeutic trial.

Diagnosis and treatment of labral tear

Objective:

To review the literature regarding diagnosis and treatment of labral tear.

Data sources:

A systematic search was performed in PubMed using various search terms and their combinations including hip, labrum, acetabular labral tear, arthroscopy, diagnosis, and anatomy.

Study selection:

For each included study, information regarding anatomy, function, etiology, diagnosis, and management of acetabular labral tear was extracted.

Results:

Five hundred and sixty abstracts about anatomy, function, etiology, diagnosis, and management of acetabular labral tear were reviewed and 66 selected for full-text review. The mechanism of labral tear has been well explained while the long-term outcomes of various treatment remains unknown.

Conclusions:

Labral tear is generally secondary to femoroacetabular impingement, trauma, dysplasia, capsular laxity, and degeneration. Patients with labral tear complain about anterior hip or groin pain most commonly with a most consistent physical examination called positive anterior hip impingement test. Magnetic resonance arthrography is a reliable radiographic examination with arthroscopy being the gold standard. Conservative treatment consists of rest, non-steroidal anti-inflammatory medication, pain medications, modification of activities, physical therapy, and intra-articular injection. When fail to respond to conservative treatment, surgical treatment including labral debridement, labral repair, and labral reconstruction is often indicated.

Primary Hip Arthroscopic Surgery With Labral Reconstruction: Is There a Difference Between an Autograft and Allograft?

Background:

Labral reconstruction has been described as a solution for the irreparable labrum. Initial techniques employed autografts, while more recent procedures have utilized allografts. No study, to our knowledge, has compared graft types.

Purpose:

To compare outcomes between patients who underwent primary labral reconstruction with a hamstring allograft versus hamstring autograft.

Hypothesis:

No significant differences in outcomes will be found between patients who underwent primary labral reconstruction with an allograft versus autograft.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data from September 2010 to March 2015 were reviewed. Inclusion criteria were primary hip arthroscopic surgery with labral reconstruction using either a hamstring allograft (ALLO group) or autograft (AUTO group), with minimum 2-year follow-up scores for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score–Sports-Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. Exclusion criteria were previous ipsilateral hip surgery, previous hip conditions, preoperative Tönnis osteoarthritis grade >1, and workers’ compensation claims. Significance was set at P = .05.

Results:

Twenty-nine patients (29 hips) were included (85.3% follow-up). There were 17 patients (17 hips) in the ALLO group and 12 patients (12 hips) in the AUTO group. All patient-reported outcome scores demonstrated significant improvements at latest follow-up except for the mHHS for the AUTO group (P = .064). Comparisons between the ALLO and AUTO groups at the preoperative and latest follow-up time points showed no significant differences (preoperative mean [range]: mHHS, 67.5 [33.0-100.0] and 65.8 [29.0-96.0], respectively [P = .826]; NAHS, 65.6 [26.3-92.5] and 58.5 [35.0-79.0], respectively [P = .322]; HOS-SSS, 43.7 [12.5-100.0] and 40.1 [19.0-78.0], respectively [P = .707]) (latest follow-up mean [range]: mHHS, 86.4 [56.0-100.0] and 81.4 [57.0-100.0], respectively [P = .46]; NAHS, 87.7 [60.0-100.0] and 82.4 [56.3-100.0], respectively [P = .396]; HOS-SSS, 81.7 [0.0-100.0] and 70.9 [27.8-100.0], respectively [P = .423]).

Conclusion:

Primary arthroscopic hip labral reconstruction yielded improvements in patient-reported outcome scores and high patient satisfaction. In this small series, no differences were found in clinical outcomes between hamstring allografts and autografts. Based on these results, hamstring allografts and autografts may be considered comparable graft choices for primary reconstruction. Because of the avoidance of donor site morbidity and the possible increase in patient satisfaction, allografts may be the preferred choice in a surgical setting when they are accessible.

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.

Knotless Anchors in Acetabular Labral Repair: A Biomechanical Comparison

PURPOSE

To analyze the failure mechanism, stiffness, and pullout strength of acetabular knotless suture anchors.

METHODS

Seven suture anchors were tested in high-density (0.48 g/cc) synthetic blocks. The anchors were implanted perpendicular to the bone block. The anchor's suture(s) were tied around a loop of 8 high-strength nonabsorbable sutures and pulled in line with the anchor at a rate of 1 mm/s until failure. The following knotless anchors were tested: Stryker Knotilus 3.5, Arthrex Pushlock 2.9, Linvatec PopLok 2.8, Linvatec PopLok 3.3, ArthroCare SpeedLock HIP (3.4-mm), and Smith & Nephew Bioraptor Knotless 2.9. The standard knot tying Smith & Nephew Bioraptor 2.9 mm served as a baseline for comparison.

RESULTS

Stiffness was highest in the Pushlock, the SpeedLock HIP, and Knotilus. At 1 mm displacement, the SpeedLock HIP exhibited significantly higher load than all other anchors, excluding the Pushlock and PopLok 3.3 (P ≤ .012 for all comparisons). Excluding the SpeedLock HIP and Knotilus, the Pushlock displayed significantly higher load than all other anchors at 2-mm displacement (P ≤ .015 for all comparisons). Maximum load was the highest for the Knotilus and Bioraptor knotted anchor (P < .001 compared with all other anchors).

CONCLUSIONS

All knotless suture anchors used in hip arthroscopy, except for the Knotilus 3.5, failed by suture pullout from the anchor. The 2 anchors with the highest maximum load, the Knotilus 3.5 and knotted Bioraptor 2.9, failed by suture failure; however, these anchors displayed the lowest stiffness and load at 1 mm displacement among all anchors tested. Stiffness and loads at clinically relevant displacements, not maximum load alone, may be most important in predicting anchor clinical performance during the early phases of labral healing.

CLINICAL RELEVANCE

Knotless suture anchors tend to fail by suture pullout from the anchor, yet the stiffness of these constructs suggests that minimal displacement of the repair will occur under physiologic loads.

Hip Arthroscopy - State of the Art in 2018

The field of hip arthroscopy has undergone considerable change in the past 25 years and continues to evolve at a rapid pace. Lessons from the early complications and challenges of hip arthroscopy have led to improved safety and refinement of instrumentation and techniques. The pathophysiology of hip injuries is better understood, and advances in surgical technique have helped expand indications, particularly as a shift from pathology resection to anatomic repair and reconstructive procedures has occurred. As the field has progressed, longitudinal outcome studies are now available to help judge efficacy. The purpose of this review is to highlight the past 30 years of hip arthroscopy, the current practice trends, and future directions of the field.

Biomechanics, anatomy, pathology, imaging and clinical evaluation of the acetabular labrum: current concepts

The labrum has been recognised to play an important role in the hip in regard to stability, fluid regulation, decreasing contact forces, proprioception and nociception. These functions are all important for normal joint homeostasis in a well-functioning hip and can be responsible for increasing joint pain, damage, instability and dysfunction when compromised. The labrum has been studied intently in the last few decades to better understand its role in the normal and the pathologic hip and how best to treat pathology that causes debilitating hip pain and dysfunction. This current concept review discusses and summarises the current literature on labral anatomy, biomechanics, pathology, clinical exam and imaging.

Labral debridement, repair and reconstruction: current concepts

Proper treatment of labral pathology is under debate. The treatments currently available to hip surgeons are: conservative treatment, labral debridement, repair and reconstruction while concomitantly addressing bony dysmorphisms. The data available to assist surgeons to make the correct treatment decisions are inconclusive. In this current concepts review, the technical aspects and currently available literature to assist in the decision-making process with these treatment modalities are reviewed. The exact indications for each procedure are still up for debate and ongoing research will better define the ideal patients for each procedure. The purpose of this narrative review was to discuss the current research on debridement, repair and reconstruction as well as the techniques that are currently reported in the literature.

Ibuprofen impairs capsulolabral healing in a rat model of anterior glenohumeral instability

BACKGROUND

Failure of glenoid labrum and capsular healing after glenohumeral dislocation can lead to persistent shoulder instability. The purpose of this study was to determine the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the healing glenoid labrum and capsule after glenohumeral dislocation in a rat model.

METHODS

Sixty-six rats had surgically induced anterior-inferior labral tears and anterior glenohumeral dislocation. Postoperatively, the animals were assigned to either normal (n = 32) or ibuprofen drinking water (n = 31). Animals were euthanized at 2 and 4 weeks postoperatively for biomechanical testing and histologic analysis.

RESULTS

The maximum load increased from 2 to 4 weeks after injury in the NSAID groups but not in the control groups. At 2 weeks, the maximum load was lower in the NSAID group compared with the control group. In a matched comparison between injured and uninjured limbs, the maximum load was significantly decreased in the injured limb of the 2-week NSAID group. At 4 weeks, the NSAID group had decreased stiffness compared with the 4-week control group.

CONCLUSIONS

In a new rat model of glenohumeral instability, the postinjury administration of ibuprofen resulted in decreased capsulolabral healing. A matched pair analysis of injured to uninjured limbs supported the findings of impaired healing in the NSAID-treated animals. These findings demonstrate that the use of NSAIDs after glenohumeral dislocation may impair capsulolabral healing and should be limited or avoided to optimize glenohumeral stability.

Labral cuff refixation in the hip: rationale and operative technique for preserving the chondrolabral interface for labral repair: a case series

Arthroscopic labral 'takedown' and refixation is utilized to permit adequate visualization and resection of the acetabular rim deformity, in patients with pincer or mixed femoroacetabular impingement. Deficiencies exist in present techniques, which include disruption of vital anatomical support and vascular structures to the labrum and chondrolabral junction, drill or anchor articular penetration risk, bunching, elevation and instability of the labrum. A new operative technique is described which preserves the important chondrolabral interface, accurately restoring the 'flap seal' of the acetabular labrum while minimizing vascular disruption and reducing the risk of drill and anchor penetration. A prospective series of 123 consecutive cases of pincer or mixed femoroacetabular impingement, treated with arthroscopic labral cuff refixation and preservation of the chondrolabral interface, is reported; operative technique and 2-year outcomes are presented.

A Comparison of Clinical Outcome Between Athletes and Nonathletes Undergoing Hip Arthroscopy for Femoroacetabular Impingement

OBJECTIVE

To compare the clinical outcome of arthroscopic surgery for femoroacetabular impingement (FAI) between athlete and nonathlete patients.

DESIGN

Retrospective case-control study. Level of Evidence III.

PATIENTS AND METHODS

Seventy-four patients who underwent arthroscopic FAI correction from March 2009 to April 2012 were enrolled in this study. The patients were divided into 2 groups, according to their sports participation (47 in the athlete group and 27 in the nonathlete group).

MAIN OUTCOME MEASURES

We reviewed clinical and radiographic data for all patients, up to a minimum of 2 years after surgery. We used analysis of covariance to compare the mean patient reported outcome scores including modified Harris hip score (MHHS) and the nonarthritis hip score (NAHS) preoperatively, at 6, 12, and 24 months after surgery.

RESULTS

The mean age at the time of surgery in the athlete group was significantly lower than that in the nonathlete group. Although there was no significant difference in preoperative MHHS and NAHS, the mean NAHS at 6, 12, and 24 months postoperatively and the mean MHHS at 24 months postoperatively in athletes were significantly higher than that in nonathletes (P < 0.05).

CONCLUSIONS

Although arthroscopic FAI correction and labral preservation surgery is generally beneficial, it appears to provide a better clinical outcome in athletes than in nonathletes.

Editorial Commentary: Hip Femoroacetabular Impingement Correction: Risk Versus Reward, or How Much Is Too Much?

When performing arthroscopic surgical management of symptomatic cases of hip femoroacetabular impingement (FAI), it is important to consider how much cam lesion resection is required, if any. Generally, failure to adequately address a cam lesion could result in progressive damage to the articular cartilage. Thus, while it is important to consider exactly how much arthroscopic intervention is necessary to achieve successful results, the potential consequences of neglecting a cam lesion are at least as worrisome as the risks of indicated cam lesion treatment.

What Are the Risk Factors for Revision Surgery After Hip Arthroscopy for Femoroacetabular Impingement at 7-year Followup?

BACKGROUND

In recent years, surgical treatment of symptomatic femoroacetabular impingement (FAI) has been increasingly performed using arthroscopy. Bony pathomorphologies and damage to the labrum as well as cartilage defects can be addressed with comparable results to open surgery with overall less surgery-related complications. Despite the increasing importance of hip arthroscopy, however, reports on midterm clinical and radiographic outcomes and comparison to open surgical hip dislocation are scarce.

QUESTIONS/PURPOSES

(1) What are the clinical and radiographic outcomes at a mean 7-year followup; (2) what is the cumulative 7-year survivorship, using the endpoints of THA, progression of osteoarthritis according to Tönnis, or poor clinical outcome with a Merle d'Aubigné score of less than 15 points, of hips with symptomatic FAI treated arthroscopically; and (3) what factors were associated with revision surgery?

METHODS

Between 2003 and 2008 we performed a total of 62 arthroscopic procedures (60 patients) for FAI. For the same indication, we also performed 571 surgical hip dislocations during that time. Standardized treatment was femoral offset correction, acetabular rim trimming, or both and treatment of labral or chondral defects. An arthroscopic approach was generally used if the pathomorphology was located in the anterosuperior quadrant of the hip and was gradually used for more complex cases. We excluded 10 hips (10 patients) in which the standardized treatment was not achieved and no offset correction or acetabular rim trimming was performed. Of the remaining 52 hips (50 patients), 39 hips underwent isolated femoral offset correction, four hips isolated acetabular rim trimming, and nine hips both procedures. At a mean followup of 7 years (range, 5-11 years), the Merle d'Aubigné clinical score was obtained and plain radiographs were examined (Tönnis grade, heterotopic ossification, lateral center-edge [LCE] angle, acetabular index [AI], extrusion index, alpha angle, and pistol grip deformity). Cumulative survivorship was calculated according to Kaplan-Meier using conversion to THA, progression of osteoarthritis (one or more Tönnis grades), or poor clinical outcome (Merle d'Aubigné score < 15 points) as endpoints. Cox regression analysis was used to identify univariate factors associated with revision surgery.

RESULTS

At last followup we detected a significant but possibly not clinically relevant increase in Merle d'Aubigné scores from preoperative levels to latest followup (14 ± 1 versus 16 ± 2, mean difference 2 points with a 95% confidence interval [95% CI] -3 to 7, p < 0.001). Six hips showed progression of osteoarthritis. Cumulative survivorship (hips free from conversion to THA, progression of osteoarthritis, or poor clinical outcome) of hips treated with hip arthroscopy for FAI at a mean followup of 7 years was 81% (95% CI, 68%-95%). Two patients (two hips, 4%) underwent THA at 7 and 9 years, respectively. An increased preoperative acetabular coverage (LCE angle, AI), increased offset in the superior portion of the femoral neck (pistol grip deformity), and a remaining pistol grip deformity postoperatively were associated with revision surgery. Any treatment of the labrum did not influence the outcome. Factors associated with failure could not be identified.

CONCLUSIONS

In this series of patients with arthroscopic treatment of symptomatic FAI, hip arthroscopy resulted in an intact hip without progression of osteoarthritis and with a Merle d'Aubigné score of ≥ 15 points in 81% of patients at 7-year followup. Increased acetabular coverage and femoral pistol grip deformity were risk factors for revision surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Arthroscopic labral repair versus labral debridement in patients with femoroacetabular impingement: a minimum 2.5 year follow-up study

PURPOSE

To compare the clinical results of labral repair with labral debridement in patients undergoing arthroscopy for femoroacetabular impingement.

METHODS

Between July 2008 and December 2011, 67 patients (73 hips) underwent arthroscopic treatment for femoroacetabular impingement. The repair group consisted of 33 patients; 18 hips with pincer only, 1 with CAM only and 15 with combined impingement. The debridement group contained 34 patients; 6 with pincer only, 5 with CAM only and 28 with combined type. The mean age in the repair group was 33.5 years (range, 30-61) and in the debridement group was 39.5 years (range, 18-59 y). At the time of last follow-up, patient's hip function was evaluated with ROM of the hip; daily Hip Outcome scores (dHOS) and Visual Analogue Score (VAS).

RESULTS

The mean follow-up was 45.2 month in the repair group and 47.2 month in debridement group. Daily hip outcome scores were significantly improved from preoperatively to last follow-up in both groups (p&lt;0.05). However, there were no statistical significant difference in dHOS between repair and debridement groups (p&gt;0.05) at last follow-up. 2 patients in the repair group and 1 patient in the debridement group had undergone total hip replacement at an average of 16 months (range, 4-32 m) after arthroscopic treatment. Hip joint instability occurred in 1 patient in the repair group due to aggressive capsular resection. This was treated by a periacetabular osteotomy.

CONCLUSIONS

No difference in hip functional outcomes was observed between labral debridement and labral repair in arthroscopic treatment of femoroacetabular impingement.

Hip labral repair: options and outcomes

The importance of the acetabular labrum has been increasingly recognized, playing a critical role in both normal anatomy and abnormal pathology of the hip joint. The labrum increases acetabular surface area and volume, providing a stable and durable articulation. The fibrocartilaginous composition affords a tissue capable of a lifetime of normal function in the absence of significant osseous pathology. In the setting of femoroacetabular impingement (FAI) or dysplasia, bony biomechanics may cause labral injury, which may translate to patient symptoms. Long-term consequences of labral tears may include joint degeneration. Labral preservation surgery emphasizes retention of the form and function of the labrum, prioritizing labral repair (in the presence of reparable tissue) and reconstruction (in the absence of reparable tissue) over debridement. Patient-reported outcomes have consistently demonstrated significantly better results following labral repair versus debridement. In conjunction with correction of osseous abnormalities, labral surgery can improve short-term outcomes and potentially reduce the risk of long-term osteoarthritis.

Traumatic, Posterior Pediatric Hip Dislocations With Associated Posterior Labrum Osteochondral Avulsion: Recognizing the Acetabular "Fleck" Sign

BACKGROUND

Traumatic dislocation of the hip is uncommon in the pediatric population. Concentric reduction is usually achieved by closed means. Open reduction may be needed if there is femoral head fracture, incarcerated fragment, or incomplete reduction due to soft tissue entrapment. We present a series of 10 patients who sustained a posterior hip dislocation or subluxation with associated osteochondral avulsion of the posterior labrum. During surgery they were noted to have a labral injury pattern not previously recognized. Such treatment was dictated by postreduction advanced imaging, which revealed a consistent acetabular "fleck" sign indicative of this labral injury, which has not been previously described in literature.

METHODS

We performed a retrospective case review of patients with traumatic posterior hip dislocation/subluxation, treated operatively for a suspected associated labral tear and fractures.

RESULTS

Ten patients (2 girls and 8 boys) were identified. Average age was 12.7 years. Eight patients had postreduction computed tomography scans, which revealed a posterior acetabular wall "fleck" sign, suggestive of osteochondral injury. The small bony fragment was consistently displaced at least 2 to 3 mm in all patients with majority of the posterior wall remaining intact. Closed reduction was felt to be congruent in 7 of the 10 patients. All patients were treated operatively for exploration and stabilization of the suspected posterior labrum pathology and associated injuries using a surgical hip dislocation. A consistent pattern of labral pathology was seen in all patients, with disruption of the posterior labrum from the superior 12 o'clock attachment to detachment at the inferior 6 o'clock location. Reattachment of the osteochondral labral avulsion was performed with suture anchors along the posterior rim, and the associated femoral head fractures were also addressed with internal fixation. Two patients had inadequate follow-up and were excluded, the average follow-up for the remaining 8 patients was 9.8 months (range, 6 to 26 mo). There were no findings of avascular necrosis in any of the 8 patients.

CONCLUSIONS

Posterior hip dislocation in children may produce an acetabular "fleck" sign on advanced imaging, which in a stable, concentrically reduced hip has been treated without surgery in the past. Acetabular fleck sign may represent a near-complete avulsion of the posterior labrum as seen in our series. We recommend a high suspicion for this type of labral pathology and surgical repair when acetabular "fleck" sign is identified with hip subluxation or dislocation. Traumatic, posterior hip dislocations in young patients may be associated with significant labral pathology. Acetabular "fleck" sign on advanced imaging may predict such pathology.

LEVEL OF EVIDENCE

IV, retrospective study.

The acetabular labrum

The acetabular labrum is a soft-tissue structure which lines the acetabular rim of the hip joint. Its role in hip joint biomechanics and joint health has been of particular interest over the past decade. In normal hip joint biomechanics, the labrum is crucial in retaining a layer of pressurised intra-articular fluid for joint lubrication and load support/distribution. Its seal around the femoral head is further regarded as a contributing to hip stability through its suction effect. The labrum itself is also important in increasing contact area thereby reducing contact stress. Given the labrum’s role in normal hip joint biomechanics, surgical techniques for managing labral damage are continuously evolving as our understanding of its anatomy and function continue to progress. The current paper aims to review the anatomy and biomechanical function of the labrum and how they are affected by differing surgical techniques.

Take home message: The acetabular labrum plays a critical role in hip function and maintaining and restoring its function during surgical intervention remain an essential goal.

Cite this article: Bone Joint J 2016;98-B:730–5.

Biomechanical Performance of Hip Labral Repair Techniques

PURPOSE

To determine the strength of various suture techniques and the impact of suture passer size on cyclically loaded hip labra.

METHODS

We assigned 63 bovine hip labra to 9 simple knotless suture technique groups using OrthoCord suture: (1) penetrating grasper (2.6 mm)-placed horizontal mattress, (2) penetrating grasper-placed vertical mattress, (3) SutureLasso (1.8 mm)-placed vertical mattress, (4) penetrating grasper-placed oblique repair, (5) penetrating grasper-placed vertical mattress plus radiofrequency, (6) SutureLasso-placed horizontal mattress, (7) SutureLasso-placed oblique mattress, (8) SutureLasso-placed horizontal mattress plus radiofrequency, and (9) SutureLasso-placed oblique mattress plus radiofrequency. After 20 cycles of uniaxial tensile loading (5 to 80 N), destructive testing was performed.

RESULTS

Penetrating grasper-placed horizontal mattress sutures showed lower ultimate failure loads than vertical and oblique mattress sutures (P < .05). Penetrating grasper-placed vertical mattress sutures had higher peak-to-peak displacement than SutureLasso-placed vertical mattress sutures (P = .04). SutureLasso-placed oblique mattress sutures had a higher ultimate load (P < .01) and stiffness (P = .04) than SutureLasso-placed horizontal mattress sutures. SutureLasso-placed horizontal mattress sutures had lower cyclic elongation than penetrating grasper-placed horizontal mattress sutures (P = .01) and lower ultimate load (P < .01) and stiffness than SutureLasso-placed vertical mattress sutures (P < .01). Horizontal mattress sutures with radiofrequency had a higher ultimate load (P = .02), stiffness, and cyclic elongation (P < .01) than without radiofrequency.

CONCLUSIONS

A horizontal mattress hip labrum stitch shows a lower ultimate failure load than vertical or oblique mattress stitches. Smaller-diameter suture-passing devices show less cyclic displacement and elongation than larger-diameter devices. Radiofrequency labral treatment does not alter vertical stitch strength but does alter horizontal mattress stitch strength.

CLINICAL RELEVANCE

Vertical and oblique stitches are stronger than horizontal stitches. A 1.8-mm passing device shows a better cyclic loading performance than a 2.6-mm device.

Open and Arthroscopic Surgical Treatment of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a common cause of hip pain, and when indicated, can be successfully managed through open surgery or hip arthroscopy. The goal of this review is to describe the different approaches to the surgical treatment of FAI. We present the indications, surgical technique, rehabilitation, and complications associated with (1) open hip dislocation, (2) reverse periacetabular osteotomy, (3) the direct anterior “mini-open” approach, and (4) arthroscopic surgery for FAI.

Description and mid-term results of the 'over the top' technique for the treatment of the pincer deformity in femoroacetabular impingement

Pincer impingement is often treated by surgical labral separation from the acetabular rim and rim reduction. A more recent technique the so-called 'over the top' involves reduction of the bony acetabular rim without separation of the labrum. Our purpose is to report mid-term results of the 'over the top' technique. Between January 2006 and January 2013 a consecutive series of patients with femoroacetabular impingement (FAI) diagnosis, treated with the 'over the top' technique were included, using the lateral approach. The Western Ontario and MacMaster (WOMAC) scores were evaluated. Fifty patients (20 males and 30 females) from the Hip and Knee Joint Reconstructive and hip arthroscopy division were included. The average age was 30.5 years old and the average follow-up was 48 months (range 70-90). Preoperative WOMAC average was 42. Post-operative WOMAC was 81.3 (P = 0.01). One patient required an arthroscopic revision due to adherences, but had a full recovery after the revision surgery. The 'over the top' technique is an excellent choice for the treatment of the pincer deformity in the FAI avoiding the injury of the chondrolabral union.

Arthroscopic treatment of femoroacetabular pincer impingement

OBJECTIVE

Arthroscopic resection of the bony overhang of the acetabular rim with concurrent treatment of associated chondrolabral injury in order to improve femoroacetabular clearance, provide symptomatic relief and in theory, delay the onset or progression of osteoarthritis of the hip.

INDICATIONS

Clinical and radiographic evidence of femoroacetabular pincer or combined impingement, with minimal to moderate degenerative change in the hip joint.

CONTRAINDICATIONS

Advanced osteoarthritis of the hip joint. Femoroacetabular pincer impingement arising from generalised overcoverage, e.g. coxa profunda. Acetabular retroversion in a dysplastic hip.

SURGICAL TECHNIQUE

Arthroscopy of the peripheral compartment, using a proximal anterolateral viewing portal and anterior and anterolateral working portals. Labral assessment, release from its capsular reflection, limited bony resection of the acetabular rim or labral ossification. Central compartment arthroscopy under traction, using the anterolateral and anterior portals alternately as viewing and working portals, and a distal anterolateral accessory portal. The labrum is detached to expose the bony overhang in the acetabular rim, which is resected with a burr. The labrum is refixed if it is of sufficient quality and debrided or resected otherwise.

POSTOPERATIVE MANAGEMENT

Labral resection: partial weight bearing, with pain-controlled progression to full weight bearing over 1-2 weeks. Labral refixation: Protected (20 kg) weight bearing for the first 4 weeks. Continuous passive motion therapy and the use of a stationary bicycle for 4 weeks, and early proprioceptive training are part of the rehabilitation regimen.

RESULTS

Arthroscopic treatment of femoroacetabular impingement has been shown to provide symptomatic relief, improve hip outcome scores and is postulated to delay progression of osteoarthritis. Better clinical outcomes can be obtained with labral refixation if the labrum is of sufficient quality.

Inflammation and Neovascularization in Hip Impingement: Not Just Wear and Tear

BACKGROUND

Femoroacetabular impingement (FAI) is a significant cause of osteoarthritis (OA) in young active patients, but the pathophysiology remains unclear. Increasingly, mechanistic studies point toward an inflammatory component in OA.

PURPOSE

This study aimed to characterize inflammatory cell subtypes and neovascularization in FAI by exploring the phenotype and quantification of inflammatory cells and neovascularization in FAI versus OA samples.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten samples of the labrum were obtained from patients with FAI (confirmed diagnosis) during open osteochondroplasty or hip arthroscopic surgery. Control samples of the labrum were collected from 10 patients with OA who were undergoing total hip arthroplasty. Labral biopsy specimens were evaluated immunohistochemically by quantifying the presence of macrophages (CD68, CD206, interleukin-13 [IL-13]), T cells (CD3), mast cells (mast cell tryptase), and vascular endothelium (CD34, vascular endothelial growth factor).

RESULTS

Labral biopsy specimens obtained from patients with FAI exhibited significantly greater macrophage, mast cell, and vascular endothelium expression compared with control OA labral samples (P < .05). The most significant difference was noted in macrophage (P < .01) and mast cell (P < .05) expression. Further subtyping of macrophages in FAI using the CD206 tissue marker and IL-13 revealed an M2 phenotype, suggesting that these cells are involved in a regenerate versus degenerate process. There was a modest but significant correlation between mast cells and CD34 expression (r = 0.4, P < .01) in FAI samples.

CONCLUSION

This study provides evidence for an inflammatory cell infiltrate in FAI along with significant neovascularization. In particular, the significant infiltration of mast cells and macrophages was demonstrated, suggesting a role for innate immune pathways in the events that mediate hip impingement.

CLINICAL RELEVANCE

Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early hip impingement.

Superior Labral Cleft after Superior Labral Anterior-to-Posterior Tear Repair: CT Arthrographic Features and Correlation with Clinical Outcome

PURPOSE

To evaluate the presence of a superior labral cleft at postoperative computed tomographic (CT) arthrography after superior labral anterior-to-posterior lesion (SLAP) repair and to correlate CT arthrographic appearance with clinical outcomes.

MATERIALS AND METHODS

The institutional review board approved this retrospective study, and the requirement to obtain informed consent was waived. Fifty-six patients who underwent CT arthrography after arthroscopic SLAP repair were included. Two musculoskeletal radiologists retrospectively reviewed CT arthrographic images for the presence, size, location, direction, and shape of a superior labral cleft, which was defined as a detectable contrast material-filled focal discontinuity of the labrum within anchor fixation sites of the glenoid. In addition, the glenoid osteolysis ratio was calculated on the basis of the CT arthrographic images. Clinical outcome was evaluated with use of the American Shoulder and Elbow Surgeons (ASES) scoring system. Continuous variables, such as patient age, interval between imaging and surgery, ASES score, and osteolysis ratio, were compared by using the Mann-Whitney U test.

RESULTS

A superior labral cleft was observed in 27 of the 56 patients (48%). The mean width and depth of the superior labral clefts was 2.1 mm ± 1.1 and 2.8 mm ± 0.8, respectively. The superior labral clefts extended posterior to the biceps anchor in 16 of the 27 patients (59%), were curved medially in 24 (89%), and had a smooth margin in 22 (81%). No significant association was observed between the presence of a superior labral cleft and the ASES score (P = .805) or patient age (P = .290). Superior labral clefts were observed more commonly in cases with a long interval since surgery (P = .007) and a high osteolysis ratio (P = .011).

CONCLUSION

Superior labral clefts are frequently observed on CT arthrographic images after arthroscopic SLAP repair and do not correlate with clinical outcome.

Prevalence of the acetabular sublabral sulcus at MR arthrography in patients under 17 years of age: does it exist?

PURPOSE

To retrospectively determine characteristics of contrast-filled acetabular labral clefts in patients under the age of 17 years at MR arthrography (Mra) correlated with arthroscopy, which may impact the thinking regarding the existence of a sublabral sulcus.

MATERIALS AND METHODS

After IRB approval, 41 patients under the age of 17 who had MRa were identified. The following observations of contrast-filled clefts were assessed: (1) presence/absence, (2) location, (3) depth, (4) abnormal signal within the labrum and (5) shape (linear, gaping, complex). Fisher's exact and the Wilcoxon matched-pairs signed-rank test were performed. Interreader agreement was calculated with Cohen's k.

RESULTS

Reader 1 found clefts in 41 %. Depth was less than half in 6%, more than half in 65% and full thickness in 29%. Shape was linear in 53%, gaping in 18% and complex in 29%. Signal changes occurred in 88%. Reader 2 found clefts in 29%. Depth was less than half in 17%, more than half in 58% and full thickness in 25%. Shape was linear in 50%, gaping in 42% and complex in 17%. Signal changes occurred in 50%. None of the clefts fulfilled the criteria for a sublabral sulcus at MRa and arthroscopy.

CONCLUSION

None of the clefts found in our subjects under the age of 17 years met the MRa and arthroscopy criteria for a sublabral sulcus, which supports the theory that such clefts represent labral tears.

Tensile properties of the human acetabular labrum and hip labral reconstruction grafts

BACKGROUND

In cases where the acetabular labrum is severely damaged and irreparable, labral reconstructions are becoming an increasingly preferred means of preserving the fluid seal effect of the labrum. However, the graft that most closely replicates the biomechanical properties of the native labrum remains undetermined.

PURPOSE

To characterize the tensile properties and geometry of the labrum, as well as iliotibial band, semitendinosus, gracilis, and anterior tibialis grafts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Five graft groups--(1) acetabular labrum, (2) iliotibial band, (3) semitendinosus, (4) gracilis, and (5) anterior tibialis--with 8 specimens per group were tested. Grafts were tested using a materials testing system in response to a stepwise sinusoidal cyclic loading protocol. Uniaxial tensile loads were initially applied from 20 to 50 N for 100 cycles at 0.5 Hz, followed by incremental increases of 50 N in the upper force every 100 cycles until failure or successful completion of 100 cycles at 300 N. This protocol was designed to be representative of progressive loading experienced during rehabilitation. Cyclic displacement was recorded after 100 (50 N), 200 (100 N), 300 (150 N), 400 (200 N), 500 (250 N), and 600 (300 N) cycles.

RESULTS

The mean elongation (95% CI) after 100 cycles from 20 to 50 N was similar for all groups: acetabular labrum, 0.68 mm (0.57-0.78 mm); iliotibial band, 0.68 mm (0.47-0.89 mm); semitendinosus, 0.68 mm (0.51-0.84 mm); gracilis, 0.62 mm (0.46-0.79 mm); and anterior tibialis, 0.66 mm (0.58-0.73 mm). After 100 cycles from 20 to 300 N (600 cycles total), the mean elongation of the labrum was 4.53 mm (3.71-5.35 mm), and the mean elongations of the iliotibial band, semitendinosus, gracilis, and anterior tibialis were 4.65 mm (3.23-6.07 mm), 4.41 mm (3.45-5.36 mm), 5.12 mm (3.09-7.16 mm), and 5.33 mm (4.40-6.25 mm), respectively.

CONCLUSION

All tested grafts and the acetabular labrum exhibited similar cyclic elongation behavior in response to simulated physiologic forces. In addition, differences in variability in both elongation and geometry existed for all graft types.

CLINICAL RELEVANCE

All tested grafts can be considered viable acetabular labrum reconstruction graft options.

No regeneration of the human acetabular labrum after excision to bone

BACKGROUND

Treatment options for a symptomatic, torn, irreparable, or completely ossified acetabular labrum are limited to either excision and/or reconstruction with grafts. In a previous animal model, regeneration of the acetabular labrum after excision to the bony rim has been shown. In humans, less is known about the potential of regeneration of the labrum. Recent studies seem to confirm labral regrowth, but it is still unclear if wide excision might be a surgical option in cases where repair is not possible.

QUESTIONS/PURPOSES

The purposes of this study were (1) to determine the extent of acetabular labrum regeneration after excision to the bony rim; and (2) to determine whether this procedure results in higher hip scores.

METHODS

We reviewed all patients treated with surgical dislocation for symptomatic femoroacetabular impingement by a single surgeon at one institution between 2003 and 2008, of whom 14 underwent wide labral excision (of at least 60°) down to bone; we used this approach when there was an absence of reparable tissue. Of these 14, nine were available for voluntary reexamination. The mean age at surgery was 38 ± 9 SD years and the mean followup was 4 ± 1 SD years. All patients consented to a physical examination and an MRI arthrogram, which was evaluated for evidence of new tissue formation by four observers. A modified Harris hip score and the UCLA were recorded.

RESULTS

Regrowth of a structure equivalent to normal labrum was not observed on the MRI arthrograms. Six of nine hips had segmental defects, bone formation was found in five, and the capsule was confluent with the new tissue in six. The mean Harris hip score at latest followup was 83 ± 14, and the mean UCLA score was 6 ± 2.

CONCLUSIONS

Resection of a nonreparable acetabular labrum down to a bleeding bony surface does not stimulate regrowth of tissue that appears to be capable of normal function by MR arthrography, and patients who underwent this procedure had lower hip scores at midterm than previously reported from the same institution for patients undergoing labral repair or sparse débridement. Based on these results, we believe that future studies should evaluate alternatives to reconstructing the labrum, perhaps using ligamentum teres, because resection seems neither to result in regrowth nor the restoration of consistently high hip scores.