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

Measure Labral Height Using MRI Prior to Hip Arthroscopy: A Diminutive Labrum Should Be Reconstructed with a Graft to Restore the Suction Seal

The acetabular labrum deepens the hip socket and provides a suction seal to the femoral head. Anatomic restoration of the suction seal is the goal of hip labral repair. Labral debridement outcomes are inferior to labral repair because this suction seal is disrupted. Labral height, surface area, and volume contribute to the suction seal and are important to consider in order to restore hip stability. Labral height should be measured on MRI prior to arthroscopy. If the labrum is insufficient, surgeons should plan labral augmentation and reconstruction using a graft. Labral reconstruction can lead to successful outcomes in cases of short labral height or hypoplastic labrum by restoring the suction seal.

Editorial Commentary: Postoperative Capsulolabral Adhesions May Contribute to the Need for Revision Hip Arthroscopy After Adequate Bony Resection in Patients With Femoroacetabular Impingement

Recent research shows a small but statistically significant reduction in hip labral size in hips requiring revision after primary arthroscopy for femoroacetabular impingement syndrome. What drives this divergence in healing? Rather than fixating on differences measured in millimeters, let's focus on labral healing resulting in the need for revision independent of residual impingement. A hypothesis is that capsulolabral adhesions, a dynamic and 3-dimensional problem, may play a role. As bony correction techniques have improved, attention must shift to the complex and undercharacterized processes of soft-tissue healing. Routine assessment and reporting of adhesions in revision femoroacetabular impingement studies are essential to our understanding of labral mechanics, failure patterns, and postoperative care.

Increased Labral Height Is Associated With Greater Distractive Stability of the Hip

PURPOSE

To examine the relationship of labral height measured on magnetic resonance imaging and resistance to axial distraction in patients with cam-type femoroacetabular impingement (FAI) syndrome.

METHODS

Patients who underwent primary hip arthroscopy for FAI syndrome between March 2020 and August 2020 were enrolled in the study traction protocol. Before any operative instrumentation, fluoroscopic images were taken of the native hip joint at 12.5-lb intervals between 0 and 100 lbs of axial traction on a postless traction table. Distraction was calculated as the difference between the total joint space at each traction interval and the baseline joint space. Labral height was measured on magnetic resonance imaging sagittal reformats at approximately 1:30 on the acetabular clockface by a musculoskeletal fellowship-trained radiologist blinded to the traction data. Descriptive statistics, independent samples t tests, Pearson χ2 tests, and Fisher exact tests were utilized in analysis.

RESULTS

Forty-three hips in 42 patients were included. Labral height was <6 mm in 19 (44%) patients and ≥6 mm in 24 (56%) patients. No statistically significant differences in age, sex, body mass index, alpha angle, Tönnis grade, lateral center edge angle, Beighton score, or presence of labral tears were observed between patients with <6 and ≥6 mm of labral height (P > .05). A greater percentage of patients with a labral height <6 mm broke their suction seal relative to patients with a labral height of ≥6 mm at 62.5 lbs (42% vs 4%; P = .003) and 100 lbs (95% vs 67%; P = .027).

CONCLUSIONS

Anterosuperior labral height ≥6 mm is associated with increased resistance to axial distraction on an examination under anesthesia in patients undergoing primary hip arthroscopy for FAI syndrome.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Patients Requiring Revision Surgery After Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome Show a Small Reduction of Postoperative Labral Size: A Propensity-Matched Controlled Study

PURPOSE

To compare the changes in labral size after primary hip arthroscopy between patients requiring revision surgery and those did not.

METHODS

Data collected between August 2016 and September 2021 were retrospectively reviewed. Patients diagnosed with femoroacetabular impingement syndrome and undergoing primary and revision hip arthroscopy at our institute were included in the revision group. Exclusion criteria were Tönnis grade >1, concomitant hip conditions, and incomplete magnetic resonance imaging (MRI) data. Patients who did not undergo revision surgery or conversion to total hip arthroplasty at minimum 2-year follow-up were matched in a 1:2 ratio and included in the control group. The labral size (width and height at 11:30, 1:30, and 3:00) on MRI (noncontrast, 3.0 T) before and after 12 months of primary surgery was compared.

RESULTS

Twenty-one patients were included in the revision group, and 42 patients were matched in the control group. In the revision group, significant reduction in labral width and height at 11:30 and 1:30, and labral width at 3:00 was observed at 12 months after primary hip arthroscopy (all with P < .05), whereas the control group did not show significant difference of changes in labral size (all with P > .05). Smaller postoperative labral width at 1:30 and 3:00 was observed in the revision group compared with the control group (all with P < .05). The revision group presented with greater reduction of labral width at all 3 positions and labral height at 1:30 compared with the control group (all with P < .05).

CONCLUSIONS

Patients requiring revision surgery after primary hip arthroscopy for femoroacetabular impingement syndrome presented with smaller postoperative labral size (less than 1 mm difference) and greater reduction of labral size (at or less than 1mm difference) on MRI 12 months after primary surgery compared with those patients that did not require later revision surgery.

LEVEL OF EVIDENCE

Level III, retrospective case control.

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.