Acetabular Labral Reconstruction Does Not Demonstrate Superior Biomechanical Properties Compared to Labral Repair or Intact Native Labrum but Is Superior to Labral Excision: A Systematic Review of Cadaveric Studies

The Beveled Rim Technique for Labral Reconstruction

Arthroscopic trimming of the acetabular rim in labral reconstruction is used to create a suitable bony surface with adequate blood flow, thereby promoting the biological conditions necessary for the healing of the labrum. The aim of this Technical Note is to present an improvement to the current arthroscopic rim preparation technique. The technique involves creating an inward beveled acetabular rim to increase the contact area of the graft on the femoral head, in order to create a greater suction seal and strategically distribute the forces generated during femoral head distraction onto both the labral graft and the acetabular rim.

Circumferential Labral Reconstruction With Knotless All-Suture Anchors Restores Hip Distractive Stability: A Cadaveric Biomechanical Analysis

BACKGROUND

The essential component of managing femoroacetabular impingement involves restoration of the original labral function. Circumferential labral reconstruction (CLR) has shown positive results. However, biomechanical studies of CLR are limited and have not established the efficacy of the modern knotless all-suture anchor (ASA) pull-through technique.

HYPOTHESES

(1) CLR with knotless ASA fixation will restore native labral suction seal biomechanics; (2) tensioning the ASA to a high-tension state will increase the peak distractive force.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen human cadaveric hips were dissected free of all soft tissue except the native labrum and transverse acetabular ligament. On an electromechanical testing system, the hips were compressively loaded to 250 N to initiate a suction seal and distracted at a rate of 10 mm/s until rupture of the suction seal. Hips were tested in 4 states: intact labrum, full labral removal, knotless CLR with moderate anchor tension, and CLR with high anchor tension. Peak distractive force (in newtons) was compared using repeated measures analysis of variance (P < .05). Acetabular bevel angles (θ) were measured at labral clockface positions outside the transverse acetabular ligament using a 3-dimensional digitizer stylus after rim preparation. Linear regression plots compared θ and peak distractive force in the CLR state.

RESULTS

Peak force values were 138.5 ± 13.6 N (mean ± SE) for the intact labrum, 18.4 ± 2.79 N for labral excision, 95.4 ± 23.3 N for moderate-tension CLR, and 126.2 ± 27.3 N for high-tension CLR. Significant differences were observed only when full labral removal was compared with the other conditions: intact (P < .001), moderate-tension CLR (P = .016), and high-tension CLR (P = .002). Steeper acetabular bevel angles (smaller θ) were correlated with greater suction seal restoration (P < .05).

CONCLUSION

CLR restored distractive stability on average to 82.0% of the intact value after labral deficiency. Retensioning did not significantly increase peak distractive forces.

CLINICAL RELEVANCE

These findings provide biomechanical validation supporting CLR using knotless ASAs in an effort to minimize volumetric bone loss and provide other surgical advantages. The prepared rim's bevel angle may be an important variable to optimize for improved suction seal restoration.

Editorial Commentary: Arthroscopic Hip Labral Preservation Combined With Bony Correction and Capsular Closure Results in Improved Patient Outcomes

Hip labral reconstruction aims to replace an irreparable or insufficient labrum with the goal of restoring the native function of the labrum and thus contribute to hip preservation. Multiple studies have reported success and improved outcomes with labral reconstruction, both in primary and revision settings. The function of the labrum includes providing additional soft-tissue coverage of the femoral head and contributing to regulation of fluid dynamics within the hip joint through the "suction seal." Labral tears and insufficiency alter hip joint biomechanics, which could result in hip microinstability and joint degeneration. Yet, although labral reconstruction is better than a labral-deficient state, labral reconstruction does not restore native hip biomechanics when compared with the native intact labrum. However, concomitant procedures to address bony morphology, hip capsule, cartilage, and adhesions in the revision setting frequently are performed at the time of labral reconstruction, making the true effect of labral reconstruction unknown. Therefore, the labrum should be considered as one of many variables when evaluating individuals with hip pain, and surgeons who perform hip arthroscopy should ensure that appropriate patient selection and additional pathology are adequately addressed in the primary and revision settings.

Effect of Acetabular Labral Tear Orientation on Hip Joint Kinematics: A Comparison of Radial Tears, Chondrolabral Junction Tears and Complex Tears in Cadaveric Hips

Background

Acetabular labral tear morphology or orientation may influence hip stability.

Hypothesis

A radial tear of the acetabular labrum would result in greater rotational and translational motion compared with a chondrolabral separation.

Study Design

Controlled laboratory study.

Methods

Included were 12 unpaired nonarthritic hip specimens, none of which had capsular laxity (8 male; mean age, 34.5 years). The specimens were stripped of all soft tissue except the hip capsule and labrum and, then potted using a custom jig. In 6 specimens, a 1-cm anterosuperior separation of the labrum from the acetabular rim (chondrolabral junction tear; CLJT) was created. In the other 6 specimens, a radial tear was created at the anterosuperior acetabulum. Subsequently, a complex labral tear was created in all specimens by adding a radial tear to the CLJT specimens and vice versa. The specimens were mounted on a load frame, and the femoral head displacement in the neutral and hyperextended positions was recorded at 5 N·m of internal/external rotation (IR/ER) torque and at 50 N of superior-inferior (S-I), anterior-posterior (A-P), and medial-lateral (M-L) force. Testing occurred at 0° extension and at maximal extension both before and after initial labral tear creation and again after creation of the complex labral tear. Before testing (intact state), the joint was vented to remove the effect of intra-articular pressure difference between the intact capsule and after capsulotomy for labral tear creation. The t test was used to calculate group differences by each range of motion measure (IR/ER and S-I, A-P, and M-L translations) for neutral and hyperextension.

Results

Neither the radial labral injury nor the CLJT produced differences from the vented state in any combination of hip position or plane of motion. The complex labral tear showed increased IR/ER rotation at maximal hip extension. There was no difference between CLJT and radial labral tear in any combination of hip position or plane of motion.

Conclusion

A simple labral tear did not affect hip joint stability when the capsule was intact, and no capsular laxity was present. A complex labral tear caused increased rotational laxity at maximal extension. Capsular laxity or a complex labral tear may be a prerequisite for labral injury to cause increased hip joint motion and/or translation.

Clinical Relevance

Study findings suggest that labral tears in the absence of capsular laxity may not play a role in producing microinstability by increasing motion or translation.

Bibliometric analysis of the acetabular labrum

The acetabular labrum (AL) plays a crucial role in the normal physiological functioning of the hip joint. This study aims to present an overview of the current status and research hotspots concerning the AL and to explore the field from a bibliometric perspective. A total of 1918 AL-related records published between January 1, 2000 and November 8, 2023 were gathered from the Web of Science Core Collection database. By utilizing tools such as HisCite, CiteSpace, VOSviewer, and the R package "bibliometrix," the regions, institutions, journals, authors, and keywords were analyzed to predict the latest trends in AL research. Global research interest and publication output related to this topic continues to escalate. The United States leads in international collaborations, number of publications, and citation frequency, underscoring its preeminent position in this field. The American Hip Institute emerged as the most prolific institution, making the greatest contribution to publications. Notably, Arthroscopy and the American Journal of Sports Medicine are the 2 most popular journals in this domain, accounting for 13.29% and 10.1% of publications, respectively, and were also found to be the most co-cited journals. Amongst authors, Benjamin G. Domb leads with 160 articles (8.35%), while Marc J. Philippon is the most frequently cited author. The keyword co-occurrence network showed 3 hot clusters, including "AL," "femoral acetabular impingement (FAI)," and "osteoarthritis." In addition, "survivorship," "FAI," and "patient-reported outcomes" were identified as trending topics for future exploration. This study represents the first comprehensive bibliometric analysis, summarizing the present state and future trends in AL research. The findings serve as a valuable resource for scholars, offering practical insights into key information within the field and identifying potential research frontiers and emerging directions in the near future.

Similar Clinical Outcomes for Arthroscopic Labral Reconstruction in Irreparable Cases Using the Indirect Head of the Rectus Femoris Tendon With an All-Inside Technique for Small Defects and the Iliotibial Band for Large Defects

PURPOSE

To evaluate the clinical outcomes and satisfaction rate of patients who underwent arthroscopic labral reconstruction for an irreparable labral tear with a minimum follow-up period of 2 years. Additionally, this study aimed to compare 2 different reconstructive techniques for small and large labral defects: the indirect head of the rectus femoris tendon (IHRFT) autograft with an all-inside technique used to repair small defects (≤3 hours) and the iliotibial band (ITB) autograft for large defects (>3 hours).

METHODS

A total of 24 hips treated with the IHRFT were compared with 24 hips treated with the ITB. All patients underwent clinical evaluation before surgery and during the most recent follow-up (42 ± 18 months). The evaluation included patient satisfaction, the modified Harris Hip Score, the Non-Arthritic Hip Score, the Hip Outcome Score, the Hip Outcome Score-sport subscale, the 12-item International Hip Outcome Tool, and the visual analog scale pain score.

RESULTS

All clinical scores were significantly improved (P < .001) at the latest follow-up in both groups. The final satisfaction was 7.1 ± 2.8 and 8.8 ± 1.6 for the IHRFT and ITB groups, respectively (P = .006). There was a significant difference in age (41.2 ± 6.0 years for the IHRFT group and 33 ± 8.5 for the ITB group; P = .004) and in surgery time (147.3 ± 39.4 minutes for the ITB group and 105.3 ± 25.7 for the IHRFT group; P < .001). One patient (4.2%) in the IHRFT group underwent total hip arthroplasty after 21.3 months (P = .999).

CONCLUSIONS

At the 2-year follow-up, treating small defects using IHRFT and larger defects using ITB resulted in good patient-reported outcome measures with a low rate of complications and failures. The ITB group reported a higher level of satisfaction at the final follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Editorial Commentary: Irreparable, Symptomatic, Hip Labral Tears Should Be Reconstructed in Patients without Osteoarthritis. However, Comparison of the Two, as Well as Allograft versus Autograft Reconstruction, Is Challenging

Hip acetabular labrum plays a chondroprotective role by maintaining stability, providing a suction seal, and contributing to load distribution. In symptomatic patients without osteoarthritis, arthroscopic labral repair has strong clinical and biomechanical data to support its use. For irreparable tears, the labrum should be reconstructed. Biomechanically, labral reconstruction does not demonstrate superiority when compared to labral repair or the intact native labrum state. However, it is superior to labral excision. One challenge in making these comparisons is the heterogeneity in surgical technique. Labral reconstruction techniques can vary significantly. In terms of reconstruction, allograft offers the advantage of no donor site morbidity, but availability, costs, and risks must be considered. Autograft use is limited by donor site morbidity and increased operative time. Direct comparisons again show no clear evidence to suggest superiority of one over the other.