The Hip Suction Seal, Part II: The Effect of Rim Trimming, Chondrolabral Junction Separation, and Labral Repair/Refixation on Hip Distractive Stability

Background: The acetabular labrum contains free nerve endings, and an unstable labrum can result in increased femoral head movement during hip motion. This can be caused by chondrolabral junction (CLJ) separation, especially in association with pincer-type femoroacetabular impingement, and may contribute to hip pain. Hypothesis: Rim resection alone has no effect on suction seal biomechanics. Further, separation of the CLJ changes hip suction seal biomechanics when compared with those of the native state, whereas repair and refixation with suture anchors restore these biomechanical parameters. Study Design: Controlled laboratory study. Methods: A total of 12 fresh-frozen human cadaveric hips were used in this study. Hips were mounted in a saline bath on a dynamic tensile testing machine and were distracted at a rate of 0.5 mm/s from neutral position. A total of 3 parameters (force, displacement, and intra-articular pressure) were measured throughout testing. Before testing, hips were randomly allocated to 1 of 2 groups: 1 that included the CLJ separation (CLJ Cut group) and 1 that did not (CLJ Intact group). Hips were tested in the following states: (1) native, (2) rim trimming, (3) separated CLJ (CLJ Cut group only), and (4) labral repair/refixation. For each group a linear mixed-effects model was used to compare biomechanical parameters between states. Results: Rim trimming did not affect any suction seal parameters relative to those of the native state. In the CLJ Cut group, no significant difference in distance to break the suction seal was observed for any states compared with that of the native state. In the CLJ Intact group, the distance to break the suction seal was significantly shorter in the labral refixation state (1.8 mm) than the native state (5.6 mm; P = .002). The maximum distraction force (62.1 ± 54.1 N) and the peak negative pressure (−36.6 ± 24.2 kPa) of the labral repair/refixation state were significantly lower than those of the native state in both groups (93.4 ± 41.7 N, P = .01; –60.7 ± 20.4 kPa, P = .02). Conclusion: Rim trimming did not change the biomechanical properties of the labral suction seal. Labral refixation resulted in a shorter distance to break the labral suction seal. This indicates that labral mobility is reduced by the labral refixation procedure, which could be beneficial in postoperative pain relief and labral healing. Clinical Relevance: The labral refixation reduced labral mobility, which could be beneficial for both pain relief and labral healing to the acetabulum after pincer-type femoroacetabular impingement resection.

Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement: Updated mean 7 year follow-up

Objectives: The acetabular labrum provides sealing function and a degree of hip joint stability. Previous early (16 month) and mid-term (mean 3.5 years) follow-up of this cohort reported better patient related outcome measures in the refixation group. To update the results of labral refixation versus focal labral excision/debridement in a cohort of patients who underwent arthroscopic correction of femoroacetabular impingement (FAI). Methods: We reported patients who underwent labral debridement/focal labral excision during a period before the development of labral repair techniques. Patients with labral tears thought to be repairable with our current arthroscopic technique were compared with patients who underwent labral refixation. In 46 hips, the labrum was focally excised/debrided (group 1); in 54 hips, the labrum was refixed (group 2). Outcomes were measured with modified-Harris-Hip-Score (mHHS), Short Form-12 (SF-12), and a visual-analog-scale (VAS) for pain preoperatively and postoperatively. Results: Mean age was 33 years in group 1 and 28 years in group 2 with mean follow-up of 7 years (range, 2-13.6 years). At mean follow-up, subjective outcomes were significantly improved (P<.01) for both groups compared with preoperative scores. The mHHS (P=.004), SF-12 (P=.016), and VAS pain scores (P<.001) were all significantly better for refixation group compared with debridement group. Although most recent outcomes for both groups fell at mean 7 years’ follow-up in comparison to 16 month and 3.5 year follow-up, the disparity between groups was greater in favor of labral refixation. Good-to-excellent results were 47.7% in debridement and 82.4% in refixation (p<.001), and failure rates were 31.8% (debridement) and 13.7% (refixation group) (p =.034). There were 4 revisions in the debridement group and none in the refixation group. Conclusion: Longer term follow-up comparing focal labral debridement/excision to refixation revealed a decrease in patient related outcome scoring and good/excellent results in both groups. Ultimately, there was a greater drop in outcome measures and good/excellent results in the debridement group and better maintenance of results in the refixation group at mean 7 years follow-up.

Arthroscopic treatment of pincer-type femoroacetabular impingement performing acetabuloplasty without labral detachment

Objectives: In order to access and resect the acetabular rim, arthroscopic acetabuloplasty was described with labral detachment. However, when the chondrolabral junction remains intact, acetabuloplasty and labral refixation can be performed maintaining an unharmed labrum. We aimed to evaluate the outcome of a group of patients treated with arthroscopic acetabuloplasty without labral detachment. Methods: During the study period, we retrospectively analyzed 44 patients with pincer-type o combined impingement and an intact chondroblabral junction, with an average followup of 32 months (range: 27-38). We excluded patients with CAM-type impingement and previous hip pathology. Radiographs were analyzed to define impingement and classify grade of osteoarthritis. Clinical evaluation consisted of preoperative and postoperative modified Harris Hip Score (mHHS) and WOMAC as well as postoperative Visual Analogue Scale (VAS) of pain and satisfaction. Reoperations were considered surgical failures for purposes of survival analysis.. Results: Mean preoperative anterior and lateral center-edge angles were 35º and 29º, respectively. Mean preoperative alfa angle was 52º. Crossover sign was found in 82% of cases. mHHS changed from 51.06 (SD 4.81) preoperatively to 84.97 (SD 12.79) postoperatively. Preoperative WOMAC was 29.18 (SD 8) and postoperative, 13.10 (SD 11). Postoperative VAS was 7.5 and 2.27 for satisfaction and pain, respectively. When comparing patients with Tönnis 0 to those with Tönnis 1, the former showed better results regarding postoperative mHHS (89.9s vs 77.85, p=0.03), pain VAS (1.5 vs 6.3, p=0.03) and satisfaction VAS (8.2 vs 6.3, p=0.01). Postoperative WOMAC was slightly better for Tönnis 0 patients (8.31 vs 19.3, p=0.05). No differences were found in preoperative WOMAC and mHHS. Three of 44 patients required a second surgical procedure and were considered failures. Survival was 100% at 24 months and 76% at 40 months (95%CI: 35%-98%). Conclusion: Arthroscopic acetabuloplasty without labral detachment achieved good clinical outcomes in all the evaluated scores. Slight degenerative changes on radiographs correlated with poorer clinical outcomes, exhibiting better results in patients without osteoarthritis.