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

Abstract

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.

The Vascularization Course of Labral Autograft and Its Effect on Tissue Healing: Acetabular Labral Augmentation Versus Labral Reconstruction in a Porcine Model

“…12,14,16,19 Despite the progress of instruments and arthroscopic techniques, the treatment of irreparable labral tears remains a great challenge for surgeons. With the importance of the chondrolabral junction being studied and discussed in several basic science studies, 22,23 labral augmentation is preferable in some cases compared with labral reconstruction for the preservation of native innervation and vascularization. Although excellent short- to midterm clinical outcomes of labral augmentation with autograft were reported by recent studies, 6,24 the potential advantages of labral augmentation compared with labral reconstruction remain unverified.…”

Minimum 2-Year Outcomes Following Arthroscopic Hip Labral Reconstruction in Adolescents and Young Adults

“…23 The function and importance of the acetabular labrum and the labral suction seal mechanism in hip biomechanics have been demonstrated. 24 Restoration of labral anatomy and function are key factors to obtain favorable outcomes following FAIS arthroscopic management. Labral repair is currently the preferred surgical option when facing labral tears, with clinical mid-term to long-term data supporting its use.…”

Allograft Labral Reconstruction of the Hip: Expanding Evidence Supporting Greater Utilization in Hip Arthroscopy

“…Within the last decade, a number of cadaveric studies have demonstrated the importance of the acetabular labrum in preserving normal hip function [37][38][39][40][41]. Composed of a complex fibrocartilaginous matrix, the hip labrum in combination with the transverse acetabular ligament form an uninterrupted ring around the acetabulum [40].…”