Is Labral Size Predictive of Failure With Repair in Hip Arthroscopy?

Editorial Commentary: Extreme Hip Labral Size (Both Small and Large) Shows Inferior Outcomes After Arthroscopic Labral Repair With Femoroacetabular Impingement Treatment

Arthroscopic management of hip femoroacetabular impingement shows reliable improvement in pain and patient-reported outcomes, high survivorship, and low conversion to total hip arthroplasty, particularly in the absence of dysplasia. Concomitant labral repair-or augmentation versus reconstruction when indicated- consistently shows better results than labral debridement. The effect of labral size on outcomes has been studies in several series. Some studies show that smaller labra show inferior outcomes after repair, others show labral size makes no difference in outcomes, and one showed that patients large labra actually had worse outcomes. Perhaps labral size at either extreme does worse. Labral size is likely to remain one of many factors worth evaluating when prognosticating repair outcomes or indicating when advanced reconstructive options are warranted.

Decreased Hip Labral Width Measured on Preoperative Magnetic Resonance Imaging Is Associated With Greater Revision Rate After Primary Arthroscopic Labral Repair for Femoroacetabular Impingement Syndrome at 5-Year Follow-Up

PURPOSE

To examine the associations between hip labral width and patient-reported outcomes, clinical threshold achievement rates, and rate of reoperation among patients with femoroacetabular impingement syndrome (FAIS) who underwent hip arthroscopy and labral repair at minimum 5-year follow-up.

METHODS

Patients were identified from a prospective database who underwent primary hip arthroscopy for treatment of labral tears and FAIS. Modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) were recorded preoperatively and at 5-year follow-up. Achievement of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) was determined using previously established values. Labral width magnetic resonance imaging measurements were performed by 2 independent readers at standardized "clockface" locations. Patients were stratified into 3 groups at each position: lower-width (<½ SD below mean), middle-width (within ½ SD of mean), and upper-width (>½ SD above mean). Multivariable regression was used to evaluate associations of labral width with patient-reported outcomes and reoperation rate.

RESULTS

Seventy-three patients (age: 41.0 ± 12.0 years; 68.5% female) were included. Inter-rater reliability for labral width measurements was high at all positions (intraclass correlation coefficient 0.94-0.96). There were no significant intergroup differences in mHHS/NAHS improvement (P > .05) or in achievement rates of MCID/SCB/PASS at each clockface position (P > .05). Eleven patients (15.1%) underwent arthroscopic revision and 4 patients (5.5%) converted to total hip arthroplasty. Multivariable analysis found lower-width groups at 11:30 (odds ratio 1.75, P = .02) and 3:00 (odds ratio 1.59, P = .04) positions to have increased odds of revision within 5 years; however, labral width was not associated with 5-year improvement in mHHS/NAHS, achievement of MCID/PASS/SCB, or conversion to total hip arthroplasty (P > .05).

CONCLUSIONS

Hip labral width <½ SD below the mean measured on preoperative magnetic resonance imaging at 11:30- and 3:00-clockface positions was associated with increased odds of reoperation after arthroscopic labral repair and treatment of FAIS. Labral width was not associated with 5-year improvement of mHHS, NAHS, achievement of clinical thresholds, or conversion to arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.

Labral repair, reconstruction, and augmentation improve postoperative outcomes in patients with irreparable or hypoplastic labra: A systematic review

PURPOSE

To review the postoperative outcomes of arthroscopic surgical options in treating irreparable and hypoplastic labrum of the hip.

METHODS

Three online databases (PubMed, MEDLINE, and EMBASE) were searched from database inception to June 27, 2023 to identify literature on treatment strategies for hypoplastic/irreparable acetabular labrum. Data pertaining to classification of irreparable tears or labral hypoplasia, indication for surgery, description of treatment, radiographic findings, and clinical outcomes were recorded and described. The methodological quality of included studies was assessed by the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

Seven level IV case series, eleven level III retrospective cohort studies, and two level II prospective cohort studies comprising 1937 patients were included for analysis. Studies were divided into an irreparable labral group comprising 1002 patients and a hypoplastic labral group comprising 935 patients. Treatments included repair, augmentation, or reconstruction. In the irreparable group, 12 studies recorded improvement of modified Harris Hip Score (mHHS) with preoperative scores ranging from 50.3 to 67.3 and postoperative scores ranging from 76.2 to 95.0. The rate of conversion to total hip arthroplasty (THA) and rate of revision arthroscopy were 6.6% and 5.9%, respectively across all studies. In the hypoplastic group, two studies that focused on repair noted no statistical difference in mHHS for repair in hypoplastic labrum vs repair in non-hypoplastic labrum. One study showed that there was a difference in post-operative mHHS for labral repair for hypoplastic vs non-hypoplastic labrum, with repair in non-hypoplastic labrum showing superior mHHS (p ​< ​0.001).

CONCLUSION

The findings of this review suggest that treatment of irreparable labra with reconstruction or augmentation results in improved patient-reported outcome measures (PROMs). For the hypoplastic labrum, primary repair also results in improvement in PROMs. Future studies focusing on the hypoplastic labra alone with an appropriate control group, rather than irreparable labral tears, are needed to properly assess patient outcomes and guide surgical indications.

Secondary Hip Labral Reconstruction Yields Inferior Minimum 2-Year Functional Outcomes to Primary Reconstruction Despite Comparable Intraoperative Labral Characteristics

PURPOSE

To compare intraoperative labral characteristics and minimum 2-year functional outcomes of allograft labral reconstruction in primary versus revision hip arthroscopy across multiple orthopaedic centers.

METHODS

A retrospective multicenter hip arthroscopy registry was queried for patients with completed labral reconstruction surgeries from January 2014 to March 2023 with completed 2-year international Hip Outcome Tool-12 (iHOT-12) reports. Age, sex, and major intraoperative variables also were collected. Patients were placed in cohorts based on whether their arthroscopic allograft labral reconstruction was a primary procedure or secondary procedure (reconstruction following failed hip arthroscopy). One-way analysis of variance was performed on continuous variables. χ2 test was performed on categorical variables. Achievement of minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and Substantial Clinical Benefit (SCB) also was assessed.

RESULTS

In total, 77 patients met the inclusion and exclusion criteria and had complete information. The primary reconstruction group (n = 50) was significantly older than the secondary reconstruction group (n = 27) (47.5 ± 10.5 vs 39.1 ± 8.8 years; P = .001). In both cohorts, most patients had labral bruising, advanced labral degeneration, and/or grade III complexity of labral tearing. There was no difference in any recorded intraoperative findings (P = .160, P = .783, P = .357, respectively). Each cohort experienced significant improvement in iHOT-12 scores (P < .0001). However, patients undergoing secondary labral reconstruction reported inferior iHOT-12 scores (60.1 ± 29.2 vs 74.8 ± 27.0; P = .030). Patients undergoing primary reconstruction were more likely to reach MCID, PASS, and nearly normal SCB (92 vs 66.7%, P = .024; 68.0 vs 40.7%, P = .021; 76.0 vs 48.1%, P = .014, respectively).

CONCLUSIONS

Primary and secondary allograft labral reconstruction show clinical improvement, but primary reconstruction demonstrates better outcomes and greater percentage of patients reaching MCID, PASS, and nearly normal SCB than reconstruction in the revision setting.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic case-control study.

Borderline Dysplastic Hips Undergoing Hip Arthroscopy Achieve Equivalent Patient Reported Outcomes When Compared With Hips With Normal Acetabular Coverage: A Systematic Review and Meta-Analysis

PURPOSE

To systematically review and meta-analyze studies reporting lateral center edge angle as it relates to patient-reported outcome (PRO) measures and clinically notable outcome assessments for patients undergoing hip arthroscopy for femoroacetabular impingement syndrome or labral pathology with borderline dysplastic hips (BDH).

METHODS

PubMed, EMBASE, and the Web of Science Core Collection databases were queried for articles evaluating lateral center edge angle as a predictor of PRO after hip arthroscopy. Articles were eligible for meta-analysis if they compared PROs measures between patients with normal acetabular coverage and borderline dysplasia and were at least level III evidence. Continuous random-effects models with standardized mean differences were used to compare postoperative Hip Outcome Score-Activities of Daily Living and sports subscales, modified Harris Hip Score, international Hip Outcome Tool scores, Satisfaction, and Visual Analog Scale Pain scores between normal coverage and borderline dysplastic groups.

RESULTS

Overall, 989 hips undergoing arthroscopy from six investigations were included in this meta-analysis, including 315 borderline dysplastic subjects (mean age 27.5 years) and 674 subjects with normal coverage (mean age 26.9 years). Borderline dysplastic and normal coverage cohorts were followed for an average of 37.0 and 36.8 months, respectively. Postoperative PRO measures (Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Subscale, modified Harris Hip Score, international Hip Outcome Tool-12, Satisfaction, and Visual Analog Scale Pain) collected approximately three years after hip arthroscopy were not markedly different between subjects with BDH when compared with patients with normal coverage.

CONCLUSIONS

In a meta-analysis of the available literature, patients with BDH are able to equally reach statistically similar clinical outcomes after isolated hip arthroscopy as compared with control subjects without dysplasia at short-term follow-up. A BDH should not be considered a contraindication to hip arthroscopy when optimal PRO achievement is the goal.

LEVEL OF EVIDENCE

Level III, Systematic Review and Meta-Analysis.

Editorial Commentary: Diminished Hip Labral Width May Predict Inferior Outcome After Hip Femoroacetabular Impingement Surgery: Diminutive Labral Width Is a Relative Indication for Labral Reconstruction

Hip labral "width" should be defined as the distance from the chondrolabral junction to the tip of the labrum in triangular cross-section. "Height" should refer to the distance from the joint surface to the perilabral recess (perpendicular to the width). "Length" is the distance from the anterior end of the labrum, adjacent to the anterior transverse acetabular ligament (TAL), to the posterior end of the labrum, adjacent to the posterior TAL (as may be relevant in reconstructions). Most studies of labral size focus on width, as it is thought to most contribute to the suction seal effect and hip stability. Magnetic resonance imaging most accurately measures labral width. Labral width at the time of surgery should be considered its maximal size; the labrum is reduced in size after repair. Hypoplastic labrums may result in worse outcomes after hip arthroscopy, and hyperplastic labrums may result in higher scores than normoplastic labrums in patients with primary femoroacetabular impingement syndrome. Diminutive labral width is a relative indication for labral reconstruction.

Changes in Hip Labral Size Two Years After Arthroscopic Repair Are Correlated With Preoperative Measurements on Magnetic Resonance Imaging

PURPOSE

The purposes of our study were 1) to investigate the potential change of labral size after arthroscopic repair and 2) to analyze the relationship between acetabular labral size and functional outcomes.

METHODS

In this retrospective study, patients diagnosed with labral tear and undergoing hip arthroscopic repair in our institution between September 2016 and December 2018 were included. Magnetic resonance imaging was obtained preoperatively and postoperatively, and the labral length and labral height were measured in three anatomic sites: 11:30, 1:30, and 3:00 positions. All patients completed at least 2-year follow-up. Patients whose preoperative labral size in any position wider than 2 standard deviation away from the mean were identified as the hypertrophic labrum group and were compared with the control in radiographic variables and patient-reported outcomes (PROs), including the visual analog scale (VAS), modified Harris Hip Score (mHHS), the International Hip Outcome Tool-12 (iHOT-12) and the Hip Outcome Score-Activities of Daily Living (HOS-ADL).

RESULTS

A total of 82 patients (82 hips) were included, and the mean follow-up period was 39.54 ± 8.48 months. Significant improvement in PROs was determined before and after surgeries. Twelve patients were identified with labral hypertrophy and had higher postoperative mHHS scores, higher postoperative iHOT-12 scores, and greater improvement in HOS-ADL compared with the control group. Patients with larger preoperative anterosuperior labral height exhibited more favorable clinical outcomes. Meanwhile, no significantly morphologic change in labral size was determined.

CONCLUSION

There is no significantly morphologic change in labral size of superior, anterosuperior, and anterior labrum after arthroscopic repair. Patients with hypertrophic labrum achieved more favorable clinical outcomes compared with those with normal-sized labrum.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

The minimal clinically important difference for the nonarthritic hip score at 2-years following hip arthroscopy

PURPOSE

The purpose of this study was to determine and establish the MCID for the NAHS at 2 years in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Patients that underwent primary hip arthroscopy for FAIS between 2010 and 2016 were analyzed for eligibility. Data were collected from a single surgeon's hip arthroscopy database. MCID was calculated for the NAHS utilizing a distribution-based method.

RESULTS

The study included 298 patients (184 females) with an average age of 40.4 ± 13.0 years and average body mass index (BMI) of 25.7 ± 4.2 kg/m². At baseline, the cohort's average NAHS score was 48.7 ± 13.6 and demonstrated an improvement of 36.5 ± 17.0 for NAHS at follow-up. This resulted in MCID values of + 8.5 for NAHS.

CONCLUSION

This is the first study to report the MCID (+ 8.5) for NAHS following primary hip arthroscopy, and as such, is a valuable contribution to future hip arthroscopy research.

LEVEL OF EVIDENCE

IV.

Arthroscopic classification of intra-articular hip pathology demonstrates at best moderate interrater reliability

PURPOSE

The purpose of this study was to report several novel classification systems for intra-articular lesions observed during hip arthroscopy, and to quantify the interrater reliability of both these novel systems and existing classifications of intra-articular lesions when tested by a group of high-volume hip arthroscopists.

METHODS

Five hip arthroscopists deliberated over shortcomings in current classification systems and developed several novel grading systems with particular effort made to capture factors important to the treatment and outcomes of hip arthroscopy for labral injury. A video learning module describing the classifications was then developed from the video archive of surgeries performed by the senior author and reviewed by study participants. Following review of the module, a pilot study was completed using five randomly selected videos, after which participating surgeons met once more to discuss points of disagreement and to seek clarification. The final video collection for testing reliability was composed of 29 videos selected with the intent of capturing all sublevels of each classification scheme. Study participants recorded their assessments using each classification scheme, and interrater reliability was calculated by a study participant not involved in grading.

RESULTS

The average kappa coefficients for the classification schemes ranged from 0.38 to 0.54, with the interrater reliability of all classification schemes except labral degeneration qualifying as moderate. The percent of cases with absolute agreement ranged from 17.2% to 51.7% across the classification systems.

CONCLUSIONS

Even among a group of high-volume hip arthroscopists who engaged in several discussions about the proposed classification schemes, grades were found to have at best moderate interrater reliability. Moderate interrater reliability is demonstrated for novel grading systems for describing labral tear complexity, labral bruising, labral size, and extent of synovitis, and fair reliability is demonstrated for labral degeneration. Further development and refinement of multifactorial grading systems for describing labral injury are indicated. Evaluating the multifactorial nature of intra-articular lesions in the hip is an important part of intraoperative decision-making and defining reliable classifications for intra-articular lesions is a critical first step towards developing generalizable criteria for guiding treatment type.

LEVEL OF EVIDENCE

Level III.

Generalized Joint Hypermobility Is Associated With Decreased Hip Labrum Width: A Magnetic Resonance Imaging-Based Study

Purpose

To explore the relationship between generalized joint hypermobility and hip labrum width.

Methods

A retrospective review was performed of a single-surgeon database containing patients who underwent hip arthroscopy between 2014 and 2017. Patients were assessed for generalized laxity via Beighton Test Scoring (BTS), which tests for hyperextension of the fifth metacarpophalangeal joint, thumb apposition, elbow hyperextension, knee hyperextension, and trunk flexion on a 9-point scale. Patients were stratified into a "high BTS cohort" with a BTS ≥4, and a control cohort with BTS <4. Magnetic resonance imaging measurements of labral width for each patient were conducted by 2 blinded, musculoskeletal fellowship-trained radiologists at standardized "clockface" locations using a previously validated technique. Statistical analyses used to determine associations between BTS and labral width included Mann-Whitney U and Fisher exact testing as well as linear regression.

Results

Thirty-four patients met inclusion criteria (17 cases, 17 controls). Both groups were composed exclusively of female patients. There was no significant difference between cases or controls in terms of age (33.3 ± 10.4 years vs 35.2 ± 8.3 years, P = .57) or body mass index (26.1 ± 9.3 vs 23.6 ± 3.4, P = .36). The high Beighton score cohort had significantly thinner labrae at the indirect rectus (5.35 ± 1.2 mm vs 7.1 ± 1.1 mm, P < .001) and anterosuperior position (5.53 ± 1.4 mm vs 7.27 ± 1.6 mm, P = .003). There was no statistical difference between the high Beighton score cohort and controls at the psoas U position (6.47 ± 1.6 mm vs 7.43 ± 1.7 mm, P = .112). Linear regression analysis demonstrated Beighton score was significantly negatively associated with labrum width at the indirect rectus position (R² = 0.33, P < .001) and the anterosuperior position (R² = 0.25, P = .004).

Conclusions

Patients with a BTS ≥4 were found to have significantly thinner labra than those with a BTS of <4.

Level of Evidence

III, retrospective comparative trial.

Editorial Commentary: Arthroscopic Treatment for Diminutive Hip Labral Size: Go Big or Go Home?

The diminutive (or hypoplastic or hypotrophic) hip labrum presents a unique surgical challenge in the setting of femoroacetabular impingement syndrome for many hip arthroscopists. Insufficient labral tissue leads to increased risk for suture cutout or overeversion, with resulting loss of suction seal when attempting arthroscopic repair. Although some surgeons have demonstrated clinical improvement after performing primary refixation of the diminutive labrum, others have reported inferior outcomes for patients with labral width <4 mm compared with patients having normal or larger labral width. Alternative treatment methods, including labral reconstruction or labral augmentation with autograft or allograft, may be effective, based on select single-surgeon studies. As further research is needed to fully evaluate outcomes of these techniques, hip arthroscopists should recognize the difficult task at hand and be prepared to use assorted treatment options to augment a diminutive labrum. Larger labra can maintain contact with the femoral head after repair, and techniques such as labral base fixation can help to preserve this interaction and recreate the suction seal.

Editorial Commentary: Hip Labral Width Does Not Matter: Now Sit Down and Eat Your Porridge!

Diagnostic hip arthroscopy precedes intervention, and surgeons use a variety of metrics to help devise and refine the treatment plan. Hypertrophic and hypotrophic labra should not be treated differently, and both can be treated successfully with labral repair. Macroscopic and tactile evaluation of labral degeneration and dynamic assessment of the labral suction seal should be used to determine whether a labral tear is best treated by labral repair, labral reconstruction, or labral augmentation.