The acetabular labrum

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.

Patients Undergoing Revision Hip Arthroscopy With Labral Reconstruction or Augmentation Demonstrate Favorable Patient Reported Outcomes: A Systematic Review

PURPOSE

To review current literature evaluating patient-reported outcomes (PROs) and survivorship in patients undergoing revision hip arthroscopy with labral reconstruction or augmentation.

METHODS

A systematic review was performed with the following key words: (revision) AND (hip OR femoroacetabular impingement) AND (arthroscopy OR arthroscopic) AND (reconstruction OR augmentation OR irreparable). PubMed, Cochrane Trials, and Scopus were queried in October 2022 using the criteria established in the Preferred Reporting Items for Systematic Reviews and Meta-analyses. Studies were included if they involved patients undergoing revision hip arthroscopy with labral reconstruction or augmentation and reported preoperative and postoperative PROs at minimum 2-year follow-up. Only original research articles were included. Survivorship was defined as a nonconversion to total hip arthroplasty. Outcomes present in 3 or more studies underwent further statistical analysis with forest plots. Heterogeneity of studies was evaluated using the I2 statistic.

RESULTS

Five studies were reviewed, including 359 revision hip arthroscopies (335 with complete follow-up) with a follow-up that ranged from 2.2 to 5.2 years. Four studies reported on outcomes after revision labral reconstruction and 1 study reported on labral augmentation. Two out of 5 included studies evaluated for statistical significance between preoperative and postoperative outcomes. Three out of 5 studies reported a rate of at least 70% for achieving minimal clinically important difference in at least 1 PRO. At minimum 2-year follow-up, survivorship ranged from 93.5% to 100%.

CONCLUSIONS

Patients that underwent revision hip arthroscopy with labral reconstruction or augmentation demonstrated improvement in PROs with mixed rates of achieving clinical benefit and rates of survivorship at minimum 2-year follow-up ranging from 93.5% to 100%.

LEVEL OF EVIDENCE

Level IV, systematic review of level III to IV studies.

How Is Variability in Femoral and Acetabular Version Associated With Presentation Among Young Adults With Hip Pain?

BACKGROUND

Acetabular and femoral version contribute to hip pain in patients with femoroacetabular impingement (FAI) or dysplasia. However, definitions and measurement methods of femoral version have varied in different studies, resulting in different "normal" values being used by clinicians for what should be the same anatomic measurement. This could result in discrepant or even inappropriate treatment recommendations.

QUESTIONS/PURPOSES

In patients undergoing hip preservation surgery, (1) what is the range of acetabular and femoral version at presentation, and how much do two commonly used measurement techniques (those of Murphy and Reikerås) differ? (2) How are differences in acetabular and femoral version associated with clinical factors and outcomes scores at the time of presentation?

METHODS

This was a retrospective analysis of data gathered in a longitudinally maintained database of patients undergoing hip preservation at a tertiary care referral center. Between June 2020 and December 2021, 282 hips in 258 patients were treated for an isolated labral tear (9% [26 hips]), hip dysplasia (21% [59 hips]), FAI (52% [147 hips]), mixed FAI and dysplasia (17% [47 hips]), or pediatric deformity (slipped capital femoral head epiphysis or Perthes disease; 1% [3 hips]) with hip arthroscopy (71% [200 hips]), periacetabular osteotomy (26% [74 hips]), surgical hip dislocation (2.5% [7 hips]), or femoral derotation osteotomy (0.5% [1 hip]). We considered those with complete radiographic data (CT including the pelvis and distal femur) and patient-reported outcome scores as potentially eligible. Exclusion criteria were age younger than 18 or older than 55 years (5 hips, 3 patients), signs of hip osteoarthritis (Tönnis grade ≥ 2; 0), pediatric deformity (slipped capital femoral head epiphysis or Perthes disease; 3 hips, 3 patients), previous femoral or acetabular osteotomy (2 hips, 2 patients), avascular necrosis of the femoral head (0), history of neuromuscular disorder (Ehlers-Danlos syndrome; 3 hips, 3 patients) or rheumatoid disease (ankylosing spondylitis; 1 hip, 1 patient), and when CT did not include the knees (19 hips, 19 patients). Based on these criteria, 249 hips in 227 patients were included. Of patients with bilateral symptomatic hips, one side was randomly selected for inclusion, leaving 227 hips in 227 patients for further analysis. The patients' median age (range) was 34 years (19 to 55 years), the median BMI (range) was 27 kg/m2 (16 to 55 kg/m2), and 63% (144) were female; they were treated with hip arthroscopy (in 74% [168]) or periacetabular osteotomy (in 23% [52]). Patients underwent a CT scan to measure acetabular version and femoral version using the Murphy (low < 10°; normal: 10° to 25°; high > 25°) or Reikerås (low < 5°; normal: 5° to 20°; high > 20°) technique. The McKibbin index was calculated (low: < 20°; normal: 20° to 50°; high > 50°). Based on the central acetabular version and femoral version as measured by Murphy, hips were grouped according to their rotational profile into four groups: unstable rotational profile: high (high acetabular version with high femoral version) or moderate (high acetabular version with normal femoral version or normal acetabular version with high femoral version); normal rotational profile (normal acetabular version with femoral version); compensatory rotational profile (low acetabular version with high femoral version or high acetabular version with low femoral version); and impingement rotational profile (low acetabular version with low femoral version): high (low acetabular version with low femoral version) or moderate (low acetabular version with normal femoral version or normal acetabular version with low femoral version). Radiographic assessments were manually performed on digitized images by two orthopaedic residents, and 25% of randomly selected measurements were repeated by the senior author, a fellowship-trained hip preservation and arthroplasty surgeon. Interobserver and intraobserver reliabilities were calculated using the correlation coefficient with a two-way mixed model, showing excellent agreement for Murphy technique measurements (intraclass correlation coefficient 0.908 [95% confidence interval 0.80 to 0.97]) and Reikerås technique measurements (ICC 0.938 [95% CI 0.81 to 0.97]). Patient-reported measures were recorded using the International Hip Outcome Tool (iHOT-33) (0 to 100; worse to best).

RESULTS

The mean acetabular version was 18° ± 6°, and mean femoral version was 24° ± 12° using the Murphy technique and 12° ± 11° with the Reikerås method. Eighty percent (181 of 227) of hips had normal acetabular version, 42% (96 of 227) to 63% (142 to 227) had normal femoral version per Murphy and Reikerås, respectively, and 67% (152 to 227) had a normal McKibbin index. Patients with an impingement profile (low acetabular version or femoral version) were older (39 ± 9 years) than patients with an unstable (high acetabular version or femoral version; 33 ± 9 years; p = 0.004), normal (33 ± 9 years; p = 0.02), or compensatory (high acetabular version with low femoral version or vice versa; 33 ± 7 years; p = 0.08) rotational profile. Using the Murphy technique, femoral version was 12° greater than with the Reikerås method (R2 0.85; p < 0.001). There were no differences in iHOT-33 score between different groups (impingement: 32 ± 17 versus normal 35 ± 21 versus compensated: 34 ± 20 versus unstable: 31 ± 17; p = 0.40).

CONCLUSION

Variability in femoral version is twice as large as acetabular version. Patients with an impingement rotational profile were older than patients with a normal, compensatory, or unstable profile, indicating there are other variables not yet fully accounted for that lead to earlier pain and presentation in these groups. Important differences exist between measurement methods. This study shows that different measurement methods for femoral anteversion result in different numbers; if other authors compare their results to those of other studies, they should use equations such as the one suggested in this study.

LEVEL OF EVIDENCE

Level III, prognostic study.

Hip Arthroscopy in Patients With Generalized Joint Hypermobility Yields Successful Outcomes: A Systematic Review

PURPOSE

To evaluate the outcomes of hip arthroscopy in patients with generalized joint hypermobility (GJH).

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. An electronic record search was performed in PubMed, Web of Science, Cochrane Library, and Embase. A 2-stage title/abstract and full-text screening was performed using the following inclusion criteria: (1) observational studies, cohort studies, and randomized controlled trials; (2) describing more than 5 patients with a mean age over 18 years and GJH; (3) undergoing arthroscopy of the hip; (4) reporting patient-reported outcome measures (PROMs), return to sport, or complications/reoperations; and (5) published in English.

RESULTS

Of the 517 articles identified, 10 studies meeting all selection criteria were included. Included studies report significant improvements in a range of different functional and pain-based PROMs. Most patients (25.0%-97.0%) in each study achieved a clinically important improvement postoperatively in at least 1 PROM. No complications were described in any of the 4 studies reporting this metric. One study each found an association between GJH and an increased risk of postoperative deep gluteal syndrome and iliopsoas tendinitis. The rate of revision arthroscopy ranged from 0% to 11.4%, and only 2 patients in a single study of 11 hips required conversion to total hip arthroplasty. No statistically significant differences were reported between patients with and without GJH with respect to any of the described outcomes.

CONCLUSIONS

Patients with GJH may achieve good outcomes following hip arthroscopy with respect to PROMs, perioperative complications, reoperation, and return to sport. With effective labral repair and capsular closure, outcomes achieved in patients with GJH are comparable to those reported in patients without hypermobility.

LEVEL OF EVIDENCE

Level IV, systematic review of level III to IV studies.

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.

Basics of hip arthroscopy: Step-by-step technique

Hip arthroscopy is a surgical procedure that has a technically challenging nature, requiring advanced spatial skills and specialised instrumentation. The most common indication for hip arthroscopy is femoroacetabular impingement, which is increasing due to improved awareness and knowledge of the condition among healthcare professionals. Hip arthroscopy requires many different checkpoints from patient positioning to capsule closure to be successfully completed. Patient positioning is one of the keystones of hip arthroscopy and the probability of a surgeon achieving successful outcomes is significantly influenced by the establishment of optimal access points. The importance of the acetabular labrum and capsule has been better understood in recent years. There has been a noticeable preference towards prioritising acetabular labral repair over debridement or excision. Similarly, consistent with the literature, capsule closure restores naive hip biomechanics more successfully and improves functional outcomes following hip arthroscopy. Osteochondroplasty is a frequently employed therapeutic intervention; yet, attaining optimal osteochondroplasty outcomes might present challenges. The aim is, to restore the full perfect sphericity of the femoral head without attenuation of the head. The aim of this article is to highlight the knowledge accumulated from experiences based on previous hip arthroscopy surgeries as a solution for future troubleshooting steps. Level of Evidence: Level V.

No Difference in Most Reported Outcome Measures for Allograft Versus Autograft for Hip Labral Reconstruction: A Systematic Review of Comparative Studies

PURPOSE

To systematically review studies comparing outcomes of allograft versus autograft for hip labral reconstruction.

METHODS

A systematic review following guidelines established by PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) was performed in 3 databases using the terms "labrum," "hip," "acetabulum," "reconstruction," "augmentation," "allograft," and "autograft." Data on study characteristics, patient demographic characteristics, follow-up time, patient-reported outcomes (PROs), rates of revision surgery, and rates of conversion to total hip arthroplasty (THA) were collected.

RESULTS

Three studies were included, with Methodological Index for Non-randomized Studies (MINORS) scores ranging from 17 to 23. Among 92 patients receiving allografts, the mean ages ranged from 30.6 to 34.8 years; mean follow-up times, from 34.6 to 66.1 months; revision rates, from 0% to 23.6%; and conversion-to-THA rates, from 0% to 20%. Among 185 patients receiving autografts, the mean ages ranged from 34.6 to 35.9 years; mean follow-up times, from 32.7 to 80.8 months; revision rates, from 0% to 7.3%; and conversion-to-THA rates, from 0% to 6.7%. One study reported significantly higher revision rates in the allograft group. All studies reported no statistically significant differences in postoperative PROs, and all postoperative PROs significantly improved compared with preoperative PROs. Rates of achievement of the minimal clinically important difference and patient acceptable symptomatic state, reported by 1 study, were statistically similar between the 2 groups and ranged from 55.6% to 100% for the allograft group and from 53.8% to 84.6% for the autograft group.

CONCLUSIONS

There were no significant differences between allograft and autograft patients in terms of postoperative PROs; however, all PRO measures were slightly higher in allograft patients. Both revision and conversion-to-THA rates were higher in allograft patients in 2 studies, with the level of significance being reached in terms of revision in 1 study. The third study reported zero revisions and conversions to THA in allograft and autograft patients.

LEVEL OF EVIDENCE

Level III, systematic review of Level II and III studies.

The Contribution of Soft Tissue and Bony Stabilizers to the Hip Suction Seal: A Systematic Review of Biomechanical Studies

BACKGROUND

Previous biomechanical studies have identified capsular closure, labral repair or reconstruction, and osteochondroplasty as important surgical interventions to improve hip stability.

PURPOSE

To investigate the outcome metrics used to quantify hip stability and assess and measure the relative contributions of the labrum, capsule, and bone to hip stability through a quantitative analysis.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed and Embase databases were searched using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included studies evaluated cadaveric hip biomechanics related to capsular, labral, and bony management during hip arthroscopy. Studies were assessed for distraction force and distance, fluid measures, and contact forces used to quantify the suction seal. Exclusion criteria included open surgery, arthroplasty, reorientation osteotomy, or traumatic dislocation.

RESULTS

A total of 33 biomechanical studies comprising 322 hips that evaluated 1 or more of the following were included: distraction force or distance (24 studies), fluid measures (10 studies), and contact forces (6 studies). Compared with a capsulotomy or capsulectomy, capsular repair or reconstruction demonstrated greater resistance to distraction (standardized mean difference [SMD], 1.13; 95% CI, 0.46-1.80; P = .0009). Compared with a labral tear, a labral repair or reconstruction demonstrated less resistance to distraction (SMD, -0.67; 95% CI, -1.25 to -0.09; P = .02). Compared with a labral debridement, repair or reconstruction demonstrated greater resistance to distraction (SMD, 1.74; 95% CI, 1.23 to 2.26; P < .00001). No quantitative analysis was feasible from studies evaluating the effect of osseous resection due to the heterogeneity in methodology and outcome metrics assessed.

CONCLUSION

Most biomechanical evidence supports capsulotomy repair or reconstruction to improve hip distractive stability at the end of hip arthroscopic surgery. While the repair of a torn labrum does not improve distractive resistance, it is superior to labral debridement in most biomechanical studies.

Can the Acetabular Labrum Be Reconstructed With a Meniscal Allograft? An In Vivo Pig Model

BACKGROUND

No single graft type has been shown to have a benefit in acetabular labral reconstruction. The native labrum and lateral meniscus share many similarities, suggesting that the meniscus may be a promising source of graft material in labral reconstruction.

QUESTIONS/PURPOSES

Using a pig model, we sought to evaluate the healing process of fresh-frozen meniscus allograft for acetabular reconstruction by assessing (1) MRI and macroscopic observations of the meniscus allograft; (2) histologic appearance and immunohistologic evaluation of the meniscus allograft, native meniscus, and labrum; (3) microscopic assessment of the native labrum and meniscus via scanning electron microscopy; and (4) biomechanical assessment of tensile properties.

METHODS

Twelve skeletally mature male miniature Bama pigs (24 hips) were randomly divided into two groups: labral defect group (control) and lateral meniscus allograft group. The selection of Bama pig specimens was based on the similarity of their acetabular labrum to that of the human acetabular labrum, characterized by the presence of fibrocartilage-like tissue lacking blood vessels. The pigs underwent bilateral hip surgery. Briefly, a 1.5-cm-long section was resected in the anterior dorsal labrum, which was left untreated or reconstructed using an allogeneic lateral meniscus. The pigs were euthanized at 12 and 24 weeks postoperatively, and then evaluated by macroscopic observations and MRI measurement to assess the extent of coverage of the labral defect. We also performed a histologic analysis and immunohistologic evaluation to assess the composition and structure of meniscus allograft, native labrum, and meniscus, as well as scanning electron microscopy assessment of the microstructure of the native labrum and meniscus and biomechanical assessment of tensile properties.

RESULTS

Imaging measurement and macroscopic observations revealed that the resected area of the labrum was fully filled in the lateral meniscus allograft group, whereas in the control group, the labral defect remained at 24 weeks. The macroscopic scores of the meniscus allograft group (8.2 ± 0.8) were higher than those of the control groups (4.8 ± 1.0) (mean difference 3.3 [95% CI 1.6 to 5.0]; p < 0.001). Moreover, in the meniscus allograft group, histologic assessment identified fibrocartilage-like cell cluster formation at the interface between the graft and acetabulum; cells and fibers arranged perpendicularly to the acetabulum and tideline structure that were similar to those of native labrum could be observed at 24 weeks. Immunohistochemical results showed that the average optical density value of Type II collagen at the graft-acetabulum interface was increased in the meniscus allograft group at 24 weeks compared with at 12 weeks (0.259 ± 0.031 versus 0.228 ± 0.023, mean difference 0.032 [95% CI 0.003 to 0.061]; p = 0.013). Furthermore, the tensile modulus of the lateral meniscus allograft was near that of the native labrum at 24 weeks (54.7 ± 9.9 MPa versus 63.2 ± 11.3 MPa, mean difference -8.4 MPa [95% CI -38.3 to 21.4]; p = 0.212).

CONCLUSION

In a pig model, lateral meniscus allografts fully filled labral defects in labral reconstruction. Regeneration of a fibrocartilage transition zone at the graft-acetabulum interface was observed at 24 weeks.

CLINICAL RELEVANCE

The use of an autograft meniscus for labral reconstruction may be a viable option when labral tears are deemed irreparable. Before its clinical implementation, it is imperative to conduct a comparative study involving tendon grafts, which are extensively used in current clinical practice.

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

PURPOSE

To systematically review and compare biomechanical properties of labral reconstruction to labral repair, intact native labrum, and labral excision in cadaveric studies.

METHODS

A search of the PubMed and Embase databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Cadaveric studies focused on hip biomechanics related to intact labrum, labral repair, labral reconstruction, labral augmentation, and labral excision were included. Investigated parameters included biomechanical data measures, such as distraction force, distance to suction seal rupture, peak negative pressure, contact area, and fluid efflux. Review articles, duplicates, technique reports, case reports, opinion articles, articles written in a language other than English, clinical studies focusing on patient-reported outcomes, studies performed in animals, and articles with no abstract available were also excluded.

RESULTS

Fourteen cadaveric biomechanical studies were included that compared labral reconstruction to labral repair (4 studies), labral reconstruction to labral excision (4 studies); and evaluation of distractive force of the labrum (3 studies), the distance to suction seal rupture (3 studies), fluid dynamics (2 studies), displacement at peak force (1 study), and stability ratio (1 study). Data pooling was not performed because of methodological heterogenicity of the studies. Labral reconstruction did not outperform labral repair in restoring the hip suction seal or any other biomechanical property. Labral repair significantly prevented greater fluid efflux when compared to labral reconstruction. Labral repair and reconstruction improved the distractive stability of the hip fluid seal from the labral tear and labral excision stage, respectively. Furthermore, labral reconstruction demonstrated to have better biomechanical properties than labral excision.

CONCLUSIONS

In cadaveric studies, labral repair or intact native labrum was biomechanically more superior than labral reconstruction; however, labral reconstruction can restore acetabular labral biomechanical properties and was biomechanically superior to labral excision.

CLINICAL RELEVANCE

In cadaveric models, labral repair outperforms segmental labral reconstruction in preserving the hip suction seal; nonetheless, segmental labral reconstruction biomechanically outperforms labral excision at time 0.

A comprehensive review of hip arthroscopy techniques and outcomes

Transforming the orthopedic landscape, hip arthroscopy pioneers a minimally invasive surgical approach for diagnosing and addressing hip pathologies. With its origins dating back to Burman's 1931 cadaveric study, this groundbreaking technique gained clinical relevance in 1939 through Takagi's report. However, the 1980s marked the actual emergence of hip arthroscopy for treating a wide range of hip disorders. Now, a staple in modern orthopedics, hip arthroscopy empowers patients with previously undiagnosed and untreated hip conditions, enabling them to obtain relief and reclaim their lives. By employing a compact camera and specialized tools, surgeons expertly navigate the hip joint, performing procedures from excising loose bodies and mending labral tears to addressing femoroacetabular impingement and tackling other intricate issues. This innovative approach has dramatically elevated patients' quality of life, allowing them to embrace targeted treatments and resume daily activities without resorting to lifestyle alterations.

Isolated Arthroscopic Debridement of Acetabular Labral Tears: High Rates of Failure and Conversion to Total Hip Arthroplasty at 13-Year Minimum Follow-up

BACKGROUND

Historically, symptomatic hip labral lesions were treated with arthroscopic debridement. Hip labral repair has become the standard treatment for labral pathology; however, to date, there are limited long-term studies regarding the outcomes of isolated labral debridement.

PURPOSE

To (1) evaluate the long-term patient-reported outcomes of isolated labral debridement, (2) report reoperation and arthroplasty rates, and (3) identify risk factors contributing to reoperation or poor clinical outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review of a prospectively generated cohort of 59 hips in 57 patients from 1996 to 2010 who underwent hip arthroscopy with labral debridement was performed. Only patients with Tönnis grade <3 were included. Additionally, given the time period analyzed, resection of cam morphology was not performed, and the interportal capsulotomy was not repaired. The pre- and postoperative modified Harris Hip Score; Hip Outcome Score (HOS)-Activities of Daily Living and -Sports scores; and reoperation, conversion to total hip arthroplasty, and risk factors were analyzed.

RESULTS

In total, 48 hips in 47 patients (14 men, 33 women; mean age, 48.0 ± 12.9 years) met inclusion criteria and were followed for a mean of 17 ± 3 years (range, 13-27 years). The mean preoperative Tönnis grade was 1.3 ± 0.6 (range, 0-2), the mean chondral acetabular International Cartilage Regeneration & Joint Preservation Society (ICRS) grade was 1.7 ± 1.6 (range, 0-4), the mean chondral femoral ICRS grade was 0.9 ± 1.4, and the mean acetabular labral articular cartilage grade was 2.5 ± 1.2 (range, 0-4). At the final follow-up, mean the modified Harris Hip Score, HOS-Activities of Daily Living score, and HOS-Sports score were 82.2 ± 16.6, 81.9 ± 20.5, and 82.2 ± 20.5, respectively. Nineteen hips underwent subsequent reoperation at a mean of 5.5 ± 6.2 years (range, 0.5-21.2 years) postoperatively, including 16 hips (33% overall) being converted to total hip arthroplasty. Higher acetabular ICRS chondral grades at the time of surgery were observed in patients who went on to subsequent surgery compared with those who did not (2.3 ± 1.6 vs 1.1 ± 1.5; P = .02). In reoperation-free hips, Tönnis grade demonstrated a trend of increasing over time (1.4 preoperatively vs 1.7 at radiographic follow-up; P = .08). At the final follow-up, 19 hips (40%) had undergone reoperation, and 5 additional hips (10%) were rated as "abnormal" or "severely abnormal" in function, resulting in an overall clinical failure rate of 50%.

CONCLUSION

Isolated labral debridement was found to result in high rates of failure and reoperation, with a third of patients being converted to arthroplasty and half of patients meeting criteria for reoperation or clinical failure. Of note, for patients remaining reoperation-free, satisfactory outcome scores were observed.

The effect of ethnicity on the age-related changes of spinopelvic characteristics: a systematic review

Aims

Spinopelvic characteristics influence the hip’s biomechanical behaviour. However, to date there is little knowledge defining what ‘normal’ spinopelvic characteristics are. This study aims to determine how static spinopelvic characteristics change with age and ethnicity among asymptomatic, healthy individuals.

Methods

This systematic review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to identify English studies, including ≥ 18-year-old participants, without evidence of hip or spine pathology or a history of previous surgery or interventional treatment, documenting lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). From a total of 2,543 articles retrieved after the initial database search, 61 articles were eventually selected for data extraction.

Results

When all ethnicities were combined the mean values for LL, SS, PT, and PI were: 47.4° (SD 11.0°), 35.8° (SD 7.8°), 14.0° (SD 7.2°), and 48.8° (SD 10°), respectively. LL, SS, and PT had statistically significant (p < 0.001) changes per decade at: −1.5° (SD 0.3°), −1.3° (SD 0.3°), and 1.4° (SD 0.1°). Asian populations had the largest age-dependent change in LL, SS, and PT compared to any other ethnicity per decade at: −1.3° (SD 0.3°) to −0.5° (SD 1.3°), –1.2° (SD 0.2°) to −0.3° (SD 0.3°), and 1.7° (SD 0.2°) versus 1.1° (SD 0.1°), respectively.

Conclusion

Ageing alters the orientation between the spine and pelvis, causing LL, SS, and PT to modify their orientations in a compensatory mechanism to maintain sagittal alignment for balance when standing. Asian populations have the largest degree of age-dependent change to their spinopelvic parameters compared to any other ethnicity, likely due to their lower PI.

Cite this article: Bone Joint Res 2023;12(4):231–244.

Tissue Regrowth and Its Vascularization Through Bone Marrow Stimulation: Microfracture at the Acetabular Rim for Irreparable Labral Tear in a Porcine Model

BACKGROUND

The treatment of irreparable acetabular labral tear remains a great challenge. Whether fibrocartilage-like tissue can regrow with sufficient volume to fill the labral defect area through bone marrow stimulation remains unknown.

PURPOSE

To characterize the healing process and vascularization course of the regrown tissue after microfracture at the acetabular rim for irreparable labral tears in a porcine model.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve pigs randomly underwent unilateral microfracture at the acetabular rim after the resection of a 10 mm-long section of labrum from 10 to 1 o'clock. Pigs were randomly sacrificed at 6 and 12 weeks postoperatively. The regrown tissues were harvested for macroscopic evaluation and histologic assessment. The regrown tissue was zoned into 2 halves to observe the vascular distribution: the capsular half (zone I) and the articular half (zone II). Each zone was divided into 2 parts: the peripheral part (IA and IIA) and the part attached to the acetabulum (IB and IIB).

RESULTS

At 6 weeks, all regrown tissue was hypotrophic with <50% filling of the labral defect. Fibrochondrocytes were concentrated at the interface between the acetabulum and the regrown tissue. The vascularization was equal among each part within the regrown tissue. As compared with regrown tissue at 12 weeks, proteoglycan and collagen type 1 and 2 were more evident within the regrown tissue at 6 weeks. At 12 weeks, tissue disintegration occurred in all regrown tissue with <25% filling of the labral defect area. The vascular structure could barely be observed, with few fibrochondrocytes found at the area adjacent to the acetabulum.

CONCLUSION

Fibrocartilage-like tissue did regrow with well-distributed vascular ingrowth of each part of the regrown tissue through bone marrow stimulation at the early stage. However, insufficient volume of the regrown tissue led to loss of the hip suction seal and subsequent tissue disintegration.

CLINICAL RELEVANCE

Microfracture at the rim of the acetabulum alone could not restore the morphology and function of the acetabular labrum. Nonetheless, microfracture at the acetabular rim might be a viable adjunct to labral reconstruction, as the well-distributed vascularization through bone marrow stimulation might overcome the obstacle of poor vascular ingrowth of the articular half of the autograft.

The Cartilage Protective Effect of Labrum Reconstruction Using Meniscus Allograft Compared with Labrum Resection in a Porcine Model

PURPOSE

This study aimed to verify the femoral head cartilage protective effect of labral reconstruction in a porcine model.

METHODS

Twelve pigs (24 hips) were divided into 3 groups: labrum defect group, lateral meniscus (LM) allograft group, and LM allograft wrapped with acellular peritoneum matrix (LM-APM) group before undergoing bilateral hip surgery. The pigs were sacrificed at 12 and 24 weeks postoperatively, while the femoral head cartilage was retrieved and then subjected to imaging measurement, macroscopic observations, and biomechanical and histological assessment.

RESULTS

Imaging measurement and macroscopic observations revealed that the defect area of the labrum was filled in LM and LM-APM allograft groups after 24 weeks, whereas the labrum defect remained at 24 weeks in the control group. The femoral head cartilage corresponding to the area of labral resection in the labral defect group had worse macroscopic Osteoarthritis Research Society International (OARSI) scores, uneven and discontinuous cartilage on hematoxylin and eosin (H&E) staining and Safranin O staining, decreased histopathology OARSI Osteoarthritis Cartilage Histopathology Assessment System (OOCHAS) scores, and decreased elastic modulus and hardness at 12 and 24 weeks after surgery compared with the meniscus allograft groups.

CONCLUSION

This study demonstrated that the LM allograft with or without APM for labral reconstruction had a chondroprotective effect on the femoral head in a porcine model.

Durable Outcomes After Hip Labral Reconstruction at Minimum 5-Year Follow-Up: A Systematic Review

PURPOSE

To systematically review and report the mid- to long-term patient reported outcomes (PROs) following hip labral reconstruction.

METHODS

A literature search of the Pubmed, Embase, and Cochrane Library databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for clinical studies reporting mid- to long-term PROs at minimum five year follow-up following arthroscopic hip labral reconstruction. A quality assessment was performed using the Methodological Index of Non-Randomized Studies (MINORS) grading system. Data collection included study characteristics, demographics, indications, radiographic metrics, perioperative findings, surgical technique, baseline and most recent PROs, and subsequent surgeries.

RESULTS

Four studies met inclusion criteria, with 182 hips (age range, 27.9 to 38.7 years) undergoing labral reconstruction in primary and revision hip surgery with minimum five year follow-up. There were three level III studies and one level IV study, with an average MINORS score of 16.6. All studies cited labral tissue characteristics as a factor for surgical indications, including the quality and/or size of the labrum. Three studies performed segmental labral reconstructions, while another study utilized a circumferential technique. Varying grafts were selected, including hamstring autograft/allograft, ligamentum teres autograft, iliotibial band autograft, and tensor fascia lata autograft. All studies demonstrated improved PROs from baseline to most recent follow-up, with four studies reporting modified Harris Hip Score (mHHS) values that increased from baseline (range, 58.9 to 66.8) to most recent follow-up (range, 80.1 to 86.3). After labral reconstruction, rates of revision arthroscopy ranged from 4.8% to 13.3% and conversion to total hip arthroplasty ranged from 1.6% to 27%.

CONCLUSION

Improved PROs were observed in all studies at minimum 5-year follow-up, suggesting that labral reconstruction can offer durable results beyond short-term follow-up. While surgical indications for all studies included labral tissue characteristics, differing graft selection and surgical techniques were utilized across studies, limiting the ability to determine an optimal treatment approach.

Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction: Comparison of Femoroacetabular Biomechanics

Background

The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal.

Purpose/Hypothesis

To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal.

Study Design

Controlled laboratory study.

Methods

Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions.

Results

PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P > .06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P = .003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62).

Conclusion

Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state.

Clinical Relevance

These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity.

Graft Options for Hip Labral Reconstruction

➢

Arthroscopic hip labral reconstruction is a complex procedure which is growing in use as indications, techniques, and surgical expertise advance.

➢

Graft selection is an important component of labral reconstruction based on relative advantages and disadvantages of available types of autografts and allografts.

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The ideal graft should mimic the native acetabular labrum form and function while also being affordable, readily available, and associated with low morbidity.

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High rates of patient satisfaction and positive patient-reported outcomes have been reported after labral reconstruction using several graft types.

It's not arthritis! Resolution of the illusion of joint space narrowing with acetabuloplasty and labral reconstruction for the calcified labrum

Labral calcification may be part of the natural history of untreated femoroacetabular impingement syndrome (FAIS) in certain patients, making it a potential target for intervention with the goal of preserving the hip joint. The purpose of this study was to investigate if calcified labra create the appearance of lateral joint space narrowing and report minimum 2-year patient-reported outcome measures (PROMs) after treating patients with arthroscopic acetabuloplasty and labral reconstruction. Prospectively collected data on patients who underwent primary hip arthroscopy for FAIS and labral tearing from February 2015 to April 2021 were reviewed. Patients treated with primary labral reconstruction for an intraoperatively confirmed diagnosis of labral calcification were included. A sub-analysis was performed for patients with a minimum of 2-year follow-up. Preoperative and postoperative PROMs for the modified Harris hip score, nonarthritic hip score, the International Hip Outcome Tool-12 and visual analog scale for pain were recorded. Forty-six hips (46 patients) were included, with 19 hips in the sub-analysis. There was a significant increase in apparent lateral joint space width (JSW) measured on supine anteroposterior (AP) pelvis radiographs with no significant changes in medial and central JSW and significant decreases in the lateral and anterior center-edge angles and alpha angle. Patients experienced significant increases in PROMs and high rates of achieving psychometric thresholds. Patients presenting with FAIS and calcified labra may have apparent lateral joint space narrowing on pre-operative supine AP pelvis radiographs. These patients have low rates of full-thickness femoral head and acetabular cartilage pathology, this apparent narrowing can be corrected and excellent outcomes and survivorship can be achieved, with primary labral reconstruction.

Symptom duration predicts inferior mid-term outcomes following hip arthroscopy

INTRODUCTION

Studies have demonstrated a negative relationship between the length of time with symptoms and patient-reported outcome measures in primary hip arthroscopy. Our aim was to expand the generalizability of this finding with a multi-center cohort.

METHODS

A multi-center hip arthroscopy registry was queried for patients undergoing primary hip arthroscopy from 2014 to 2017. Patients were stratified according to whether pre-operative symptom duration exceeded two years or did not exceed two years. A Wilcoxon rank sum test was performed for differences in two year post-operative outcome scores. Logistic regression models analyzed the influence of symptom duration on achieving clinically meaningful thresholds (minimum clinically important difference, patient-acceptable symptom state, substantial clinical benefit) when controlling for baseline scores, age, BMI, and sex.

RESULTS

Seven hundred forty-four patients met the inclusion criteria, from which 620 had complete outcomes information. The mean ± SD 2-year iHOT-12 scores of patients with symptom duration greater than two years (69 ± 26) were significantly lower than patients with symptom duration less than two years (77 ± 23) (Dunn test, p < 0.001). Chronic duration of pain was a negative predictor of achieving iHOT-12 MCID (0.47 [0.31-0.72]), PASS (0.53 [0.37-0.76]), and SCB (0.67 [0.47-0.94]).

CONCLUSION

When controlling for differences in baseline demographic factors and pre-operative iHOT-12 scores, patients with chronic pain report poorer functional outcomes at mid-term follow-up. These results suggest that chronic pain predicts inferior outcomes from primary hip arthroscopy and that surgical intervention at earlier time points may be beneficial in achieving better outcomes.

Hip Labral Reconstruction With a Polyurethane Scaffold: Restoration of Femoroacetabular Contact Biomechanics

Background:

Many advances have been made in hip labral repair and reconstruction and in the restoration of the suction seal.

Purpose/Hypothesis:

The purpose of this study was to evaluate the biomechanical effects of segmental labral reconstruction with a synthetic polyurethane scaffold (PS) in comparison with segmental labrectomy. Our hypothesis was that reconstruction with a icroporous polyurethane implant would normalize joint kinetics of the hip and restore the suction seal.

Study Design:

Controlled laboratory study.

Methods:

We used 10 hips from 5 fresh-frozen pelvises with an intact acetabular labrum without osteoarthritis. Using an intra-articular pressure measurement system, the contact area, contact pressure, and peak force were assessed for the following conditions: intact labrum, partial anterosuperior labrectomy, and PS reconstruction. For each condition, all specimens were analyzed in 4 positions (90° of flexion, 90° of flexion and internal rotation, 90° of flexion and external rotation, and 20° of extension) and underwent a labral seal test. The relative change from the intact condition was determined for all conditions and positions.

Results:

Compared with the intact labrum, labrectomy resulted in a significant decrease in the contact area (P < .001) and a significant increase in the peak force (P < .001) and contact pressure (P < .001) across all positions. Compared with labrectomy, PS reconstruction resulted in a significant increase in the contact area (P < .001) and a significant decrease in the contact pressure (P ≤ .02) and peak force (P < .001) across all positions. Compared with the intact labrum, PS reconstruction restored the contact area and peak force to normal values in all positions (P > .05), whereas the contact pressure was significantly decreased compared with labrectomy (P < .05) but did not return to normal values. The labral seal was lost in all specimens after labrectomy but was restored in 80% of the specimens after PS reconstruction.

Conclusion:

Femoroacetabular contact biomechanics significantly worsened after partial labrectomy; reconstruction using a PS restored the contact area and peak force to the intact state and improved the contact pressure increases seen after partial labrectomy. The contact area and peak force were normalized, and the labral seal was re-established in most cases.

Clinical Relevance:

This study provides biomechanical evidence for the use of a scaffold for labral reconstruction.

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

BACKGROUND

The preservation of the native labral vascularization is assumed to be the potential advantage of acetabular labral augmentation, the effect of which remains unknown.

PURPOSE

To identify the vascular distribution within the labral autograft and its effect on the healing process between labral augmentation (AUG) and reconstruction (RECON) in a porcine model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 36 pigs randomly underwent unilateral labral augmentation or reconstruction (AUG group, n = 18; RECON group, n = 18). The pigs were randomly sacrificed at 6, 12, and 24 weeks postoperatively. The labral autografts were harvested for macroscopic evaluation and histologic assessment. The labral autograft was zoned into 2 halves to observe the vascular distribution: the capsular half (zone I) and the articular half (zone II). Each zone was divided into 2 parts: the peripheral part (IA and IIA) and the part attached to the acetabulum (IB and IIB).

RESULTS

At 6 weeks, there existed more vascular ingrowth in zone I, whereas zone IIB appeared nearly avascular in both groups. At 12 weeks, the area with the greatest vascularity was zone II in the RECON group and zone IA in the AUG group. The vascularity was concentrated at zones IA and IIA in both groups at 24 weeks. The labral autografts were hypertrophic with sufficient filling of the labral defect in both groups at 6 weeks. At 12 weeks, an insufficient volume of the articular half was observed in 3 of 6 labral autografts in the RECON group, while all autografts remained well integrated with the chondrolabral junction in the AUG group. At 24 weeks, unsatisfactory merging of the labral autograft with the cartilage at the articular side was found in 2 of 6 labral autografts in the RECON group, which was not observed in the AUG group despite the sufficient volume of autografts labrum in both groups.

CONCLUSION

Slow vascular ingrowth within the articular half might account for the poor healing of the reconstructed labral autograft. Labral augmentation provides the possibility of better tissue healing because of the preservation of the original chondrolabral junction compared with labral reconstruction.

CLINICAL RELEVANCE

Labral augmentation might be a feasible alternative to labral reconstruction under the condition of viable labral remnants.

Acetabular paralabral cysts demonstrating perineural propagation

OBJECTIVE

Acetabular paralabral cysts are common and are almost always associated with labral tears. Uncommonly, they extend into the periacetabular soft tissues or may propagate along peripheral nerves causing pain and hip dysfunction. The aim was to evaluate the clinical and MRI presentations of such cases including perineural propagation.

METHODS

Retrospective cross-sectional study with a search of electronic health records for cases of acetabular paralabral cysts demonstrating perineural propagation was performed. Clinical and MR imaging features were tabulated after re-review by experienced musculoskeletal radiologists, and available outcomes were recorded. Descriptive statistics were performed.

RESULTS

14 cases were recorded. The mean age was 56.9 years (range = 30-79 years) and female:male ratio was 1:2.6. The commonest presenting complaint was hip pain (10/14, 71.4%). Other complaints included groin pain, perineal pain and hip dysfunction. No symptoms were attributed to the acetabular paralabral cyst in 3/14 patients (21.4%). None had foot drop. The cysts were multilocular in all cases and were homogenously T2 hyperintense in 13/14 (92.9%). Labral tears were identified in 11/14 cases (78.6%). The sciatic nerve was most commonly involved in 5/14 cases (35.7%) with the obturator, medial femoral cutaneous nerve, femoral nerve, superior and inferior gluteal nerves also affected.No intervention was undertaken in 9/14 cases (64.3%). 5/14 (35.7%) underwent image guided aspiration and corticosteroid injection. 4/5 such patients reported reduced pain following the procedure.

CONCLUSION

Paralabral cysts demonstrating perineural propagation are uncommon and exhibit varied presentations. Most patients who underwent image-guided or surgical interventions reported an improvement in symptoms.

ADVANCES IN KNOWLEDGE.

This is the first description of a series of patients with acetabular paralabral cysts demonstrating perineural propagation in the literature. A comprehensive description of their clinical and imaging characteristics and interventions/outcomes where relevant is provided.

Primary Arthroscopic Labral Management: Labral Repair and Complete Labral Reconstruction Both Offer Durable, Promising Results at Minimum 5-Year Follow-up

BACKGROUND

Increased understanding of the acetabular labrum's role in hip joint biomechanics has led to a greater focus on the conservation and restoration of normal labral anatomic characteristics; however, labral repair is often not possible in the setting of severe intrasubstance damage or deficiency.

PURPOSE

To compare 5-year postoperative patient-reported outcomes between hips treated with primary complete arthroscopic labral reconstruction and those treated with primary labral repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All hips that underwent primary labral repair or reconstruction by the senior surgeon between January 2015 and December 2015 were included. Hips that had undergone a previous intra-articular procedure were excluded. Visual analog scales and patient-reported outcome (PRO) instruments were completed by patients within 1 week before surgery as a baseline measurement, between 22 and 26 months postoperatively for 2-year outcomes, and between 58 and 62 months for 5-year outcomes. PRO scores collected included the modified Harris Hip Score (mHHS), the 12-Item International Hip Outcome Tool, and the visual analog scale for pain and satisfaction. Pain and satisfaction were assessed using visual analog scales.

RESULTS

A total of 68 primary labral repairs and 62 primary complete labral reconstructions were included in the final analysis. Patients in the reconstruction cohort were older (38.3 vs 29.9 years; P < .001), had a higher incidence of severe labral tearing (62.90% vs 5.88%; P < .001), required a greater number of concomitant procedures (P < .001), and were more likely to have Beck grade III or IV chondral damage (12.94% vs 1.47%; P < .001). Both groups demonstrated statistically significant increases in outcome scores at minimum 5-year follow-up. Patients who underwent labral reconstruction had a significantly greater increase in mHHS from the preoperative assessment to latest follow-up compared with patients undergoing labral repair (27.43 vs 17.13; P = .04). No statistically significant differences between the 2 cohorts were found in achievement of minimal clinically important difference, Patient Acceptable Symptom State, maximum outcome improvement, and substantial clinical benefit at latest follow-up (P > .05). In total, 2 patients in the repair cohort and 3 patients in the reconstruction cohort required revision arthroscopy (P = .574). Further, 1 patient from each group converted to arthroplasty (P = .947).

CONCLUSION

The results of this study suggest that primary complete labral reconstruction is a viable surgical option for hips with moderate to severe labral pathology. At minimum 5-year follow-up, labral reconstruction produced similar outcomes to labral repair despite less favorable preoperative patient characteristics in the reconstruction cohort.

An Increased Allograft Width for Circumferential Labral Reconstruction Better Restores Distractive Stability of the Hip: A Cadaveric Biomechanical Analysis

BACKGROUND

Questions remain about whether circumferential labral reconstruction (CLR) using an iliotibial band (ITB) allograft can effectively restore the labral suction seal of the hip.

HYPOTHESES

(1) CLR with an ITB allograft >6.5 mm would restore distractive stability force to that of the intact labrum. (2) CLR with an ITB allograft >6.5 mm would achieve significantly superior distractive stability force compared with CLR with an ITB allograft <6.5 mm.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 6 fresh-frozen pelves with attached femurs (n = 12 matched hemipelves) from male donors were procured and dissected free of all soft tissue, including the hip capsule but preserving the native labrum, transverse acetabular ligament, and ligamentum teres. Potted hemipelves were placed in a saline bath and securely fixed to the frame of a hydraulic testing system. A 500-N compressive load was applied, followed by femoral distraction at a rate of 5.0 mm/s until the suction seal ruptured. Force and femoral displacement were continually recorded. Force versus displacement curves were plotted, the maximum force was recorded, and the amount of femoral distraction to rupture the suction seal was determined. After intact testing, the labrum was excised, and specimens were retested using the same protocol. CLR was subsequently performed twice in a randomized fashion using (1) an ITB allograft with a width >6.5 mm (7.5-9.0 mm) and (2) an ITB allograft with a width <6.5 mm (4.5-6.0 mm). Specimens were retested after each CLR procedure. Force (in Newtons) and femoral distraction (in millimeters) required to rupture the suction seal were measured and compared between the 4 testing states (intact, deficient, CLR <6.5 mm, and CLR >6.5 mm) using repeated-measures analysis of variance.

RESULTS

On average, intact specimens required 148.4 ± 33.1 N of force to rupture the hip suction seal, which significantly decreased to 44.3 N in the deficient state (P < .001). CLR with ITB allografts <6.5 mm did not improve the maximum force (63 ± 62 N) from the deficient state (P = .42) and remained significantly lower than the intact state (P < .01). CLR with ITB allografts >6.5 mm recorded significantly greater force to rupture the suction seal (135.8 ± 44.6 N) compared with both the deficient and CLR <6.5 mm states (P < .01), with a mean force comparable with the intact labrum (P = .59). The amount of femoral distraction to rupture the suction seal demonstrated similar findings.

CONCLUSION

In a cadaveric model, CLR using ITB allografts >6.5 mm restored the distractive force and distance to the suction seal rupture to values comparable with hips with an intact labrum. CLR using ITB allografts >6.5 mm outperformed CLR with ITB allografts <6.5 mm, demonstrated by a significantly higher force to rupture the suction seal and increased distraction before the rupture.

CLINICAL RELEVANCE

The results of this cadaveric investigation suggest that using wider labral allografts during CLR will provide the distractive force required to rupture the suction seal and immediate postoperative stability of the hip, although further studies are required to determine if these results translate to improved clinical outcomes.

Comparison of early outcomes of arthroscopic labral repair or debridement

Aims

This study uses prospective registry data to compare early patient outcomes following arthroscopic repair or debridement of the acetabular labrum.

Methods

Data on adult patients who underwent arthroscopic labral debridement or repair between 1 January 2012 and 31 July 2019 were extracted from the UK Non-Arthroplasty Hip Registry. Patients who underwent microfracture, osteophyte excision, or a concurrent extra-articular procedure were excluded. The EuroQol five-dimension (EQ-5D) and International Hip Outcome Tool 12 (iHOT-12) questionnaires were collected preoperatively and at six and 12 months post-operatively. Due to concerns over differential questionnaire non-response between the two groups, a combination of random sampling, propensity score matching, and pooled multivariable linear regression models were employed to compare iHOT-12 improvement.

Results

A total of 2,025 labral debridements (55%) and 1,659 labral repairs (45%) were identified. Both groups saw significant (p < 0.001) EQ-5D and iHOT-12 gain compared to preoperative scores at 12 months (iHOT-12 improvement: labral repair = +28.7 (95% confidence interval (CI) 26.4 to 30.9), labral debridement = +24.7 (95% CI 22.5 to 27.0)), however there was no significant difference between procedures after multivariable modelling. Overall, 66% of cases achieved the minimum clinically important difference (MCID) and 48% achieved substantial clinical benefit at 12 months.

Conclusion

Both labral procedures were successful in significantly improving early functional outcome following hip arthroscopy, regardless of age or sex. Labral repair was associated with superior outcomes in univariable analysis, however there was no significant superiority demonstrated in the multivariable model. Level of evidence: III Cite this article: Bone Jt Open 2022;3(4):291–301.

Midterm Outcomes After Hip Labral Augmentation in Revision Hip Arthroscopy

BACKGROUND

Labral augmentation has emerged as an essential procedure to address a deficient or irreparable labrum while preserving native labral tissue and restoring the hip suction seal mechanism.

PURPOSE

To evaluate midterm outcomes of arthroscopic hip labral augmentation for labral insufficiency after previous hip arthroscopy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients were identified from a prospectively collected database who underwent arthroscopic hip labral augmentation between January 2011 and January 2017 with a minimum 3-year follow-up. Pre- and postoperative patient-reported outcome scores were compared and included the 12-Item Short Form Health Survey physical and mental component summaries, Western Ontario and McMaster Universities Osteoarthritis Index, modified Harris Hip Score (mHHS), and Hip Outcome Score (HOS) (Activities of Daily Living [ADL] and Sport). Postoperative Tegner Activity Scale and patient satisfaction (1-10) scores were also evaluated. The minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) between the preoperative and minimum 3-year follow-up scores were calculated.

RESULTS

A total of 88 patients (39 men, 49 women) underwent revision hip arthroscopy with labral augmentation. The average age was 32.8 ± 11 years. Of these, 77 patients (88%) were available for the minimum 3-year follow-up. The survivorship (absence of conversion to total hip arthroplasty) at 3 years and 5 years was 93% at both time points, with a mean survival time of 8.5 years (95% CI, 8.0-8.9). Eleven patients (14%) required revision arthroscopic surgery for continued pain. Revisions occurred at a mean of 2.6 ± 1.4 years after augmentation. The mean follow-up was 5.2 ± 1.2 years (range, 3-9 years). For patients not requiring subsequent surgery (n = 61), all patient-reported outcome measures significantly improved, which included a 20-point increase in HOS-ADL (MCID, 82%; PASS, 72%) and mHHS (MCID, 78%; PASS, 70%). The median postoperative Tegner score was 4 (range, 1-10). The median postoperative patient satisfaction score was 9 out of 10 (range, 1-10).

CONCLUSION

Arthroscopic hip labral augmentation is a successful treatment option for patients with labral insufficiency after previous hip arthroscopy, demonstrating improved patient-reported outcomes and survivorship of 93% at 3 years and 5 years. This technique provides a valuable labral preservation option when addressing hip labral pathology when viable native labral tissue remains.

Workers' Compensation Patients Improved After Hip Arthroscopy for Labral Tears: A 5-Year Outcome Propensity Score-Matched Study

BACKGROUND

The workers' compensation (WC) status has been associated with inferior outcomes in orthopaedic procedures and is usually excluded from clinical outcome studies. Therefore, comparative studies based on WC status are scarce.

PURPOSE

(1) To determine outcomes of patients with WC claims treated with hip arthroscopy for labral tears at a minimum 5-year follow-up and (2) to compare these findings with a propensity score-matched control group without WC claims.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were propensity score matched to a control group without WC claims. Data were prospectively collected for all patients undergoing hip arthroscopy. Patients were included if they received primary hip arthroscopy for labral tears in the setting of femoroacetabular impingement, had a WC claim, and had preoperative and minimum 5-year follow-up patient-reported outcomes ([PROs]; modified Harris Hip Score [mHHS], Non-Arthritic Hip Score [NAHS], Hip Outcome Score-Sports Specific Subscale [HOS-SSS], and visual analog scale [VAS] for pain). Clinical outcomes were measured using the Patient Acceptable Symptom State (PASS), minimal clinically important difference (MCID), and maximum outcome improvement satisfaction threshold (MOI).

RESULTS

A total of 111 from 132 (84.1%) eligible WC patients met the inclusion criteria with an average follow-up time of 80.3 ± 37.3 months. WC cases demonstrated significant improvement from preoperatively to a minimum 5-year follow-up for mHHS, NAHS, HOS-SSS, and VAS for pain (P < .05). WC patients returned to work at a 66% rate, with an average clearance time of 4.7 months to light duty and 9.5 months to heavy duty. When compared with the control group, the WC group demonstrated lower pre- and postoperative PROs (P < .05); however, WC cases had a greater magnitude of improvement (ΔmHHS [P = .0012], ΔNAHS [P < .001], and ΔHOS-SSS [P = .012]). Rates of achieving MCID and MOI were similar in both groups (P > .05). The WC group went on to receive a future arthroscopy in 19 cases (17.1%), while 10 cases (4.5%) in the control group required revision arthroscopy (P < .001). Patients in both the WC and the control groups converted to total hip arthroplasty at similar rates (13.3% and 15.4%, respectively; P > .05).

CONCLUSION

Patients with WC claims treated with hip arthroscopic surgery showed significant improvement and high rates of returning to work at a minimum 5-year follow-up. Although having lower scores in PROs and achieving PASS rates, no differences were found in MCID and MOI rates. Furthermore, WC patients had a greater magnitude of improvement from preoperatively to a minimum 5-year follow-up after hip arthroscopy. Therefore, even though more studies are needed to determine the causes of inconsistent outcomes in the WC population, hip arthroscopy can effectively treat labral tears in the setting of femoroacetabular impingement, regardless of the WC status.

Does labral treatment technique influence the outcome of FAI surgery? A matched-pair study of labral reconstruction versus repair and debridement with a follow-up of 10 years

The aim of this study was to analyze the long-term clinical outcomes of labral reconstruction in patients undergoing femoro-acetabular impingement (FAI) surgery and compare them with labral repair and debridement. This is a single-center, single-surgeon, retrospective match-paired study from a prospectively collected hip preservation database. All patients underwent a hip surgical dislocation for FAI surgery. Eight patients underwent labral reconstruction with the ligamentum teres and were matched on sex, age and body mass index with 24 labral repair and 24 labral debridement (1:3). Failure was defined as conversion to total hip replacement (THR) and patient-reported outcome measures (PROMs) were collected. Mean follow-up was 9.8 years ±2.6 (5.2–13.9). There was a significant improvement in postoperative PROMs in the three groups regarding the WOMAC total, WOMAC function, HOOS-QoL, HOOS-ADL and HOOS-SRA (P < 0.05). There was no statistical difference between the three groups regarding postoperative PROMs and change in PROMs (P > 0.05). A total of 10 hips underwent joint replacement surgery at a mean time of 7.9 ± 3.5 years (2.4–12). There was no statistically significant difference between the three groups regarding the conversion rate to THR (P = 0.64) or time between surgery and conversion to THR (P = 0.15). Compared to a match-pair group of labral repair and debridement, labral reconstruction with ligamentum teres provides similar survival with conversion to a THR as an endpoint, as well as similar improvement in PROMs. Labral treatment can be safely adapted at the nature of the labral lesion with a treatment ‘à la carte’.

Biomechanical analysis of fixation methods in acetabular fractures: a systematic review of test setups

Purpose

Optimal anatomical reduction and stable fixation of acetabular fractures are important in avoiding secondary dislocation and osteoarthritis. Biomechanical studies of treatment options of acetabular fractures aim to evaluate the biomechanical properties of different fixation methods. As the setup of the biomechanical test can influence the experimental results, this review aimed to analyze the characteristics, comparability and clinical implications of studies on biomechanical test setups and finite element analyses in the fixation of acetabular fractures.

Methods

A systematic literature research was conducted according to the PRISMA guidelines, using the PubMed/MEDLINE and Web of Science databases. 44 studies conducting biomechanical analyses of fixation of acetabular fractures were identified, which met the predefined inclusion and exclusion criteria and which were published in English between 2000 and April 16, 2021. The studies were analyzed with respect to distinct parameters, including fracture type, material of pelvis model, investigated fixation construct, loading direction, loading protocol, maximum loading force, outcome parameter and measurement method.

Results

In summary, there was no standardized test setup within the studies on fixation constructs for acetabular fractures. It is therefore difficult to compare the studies directly, as they employ a variety of different test parameters. Furthermore, the clinical implications of the biomechanical studies should be scrutinized, since several test parameters were not based on observations of the human physiology.

Conclusion

The limited comparability and restricted clinical implications should be kept in mind when interpreting the results of biomechanical studies and when designing test setups to evaluate fixation methods for acetabular fractures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-022-01936-9.

How to Report: Hip MRI

Writing a good magnetic resonance imaging (MRI) hip report requires a sound understanding of hip anatomy, imaging, and related pathologies. The structures of the hip most prone to pathology are the articular surfaces, labrum, subchondral bone, and gluteal tendons. Particular attention should be paid to abnormal hip morphology that is relatively common and can manifest as internal or external hip derangement. It is essential to appreciate and report the specific features of each pathology that carry clinical significance to aid patient management. This article is aimed at trainee radiologists and those less experienced with reporting hip MRI, focusing on the essential features to comment on and providing examples of terminology to use and MR images to illustrate these features.

Hip Labral Reconstruction: Techniques and Outcomes

PURPOSE OF REVIEW

With increased understanding of the biomechanical function of the acetabular labrum, more attention has been directed towards surgical techniques that preserve or restore normal joint anatomy. While labral repair has been shown to produce superior outcomes to labral debridement, repair is not always possible in the setting of severe labral intrasubstance tearing or deficiency. These patients were previously left without suitable arthroscopic treatment options.

RECENT FINDINGS

Labral reconstruction is an emerging procedure that has been shown to offer promising outcomes for traditionally difficult-to-treat hip pathology. Short- and mid-term follow-up studies have consistently demonstrated significant improvement in patient-reported outcomes, function, and patient satisfaction postoperatively, often despite less favorable preoperative characteristics. Labral reconstruction is a viable arthroscopic treatment option that has been shown to reliably produce clinically meaningful results in patients with severe labral pathology that is not amenable to repair/refixation or augmentation.

In search of labral restoration function with hip arthroscopy: outcomes of hip labral reconstruction versus labral repair: a systematic review

PURPOSE

To perform a systematic review comparing patient-reported outcomes (PROs) in patients who underwent hip arthroscopy with labral repair versus labral reconstruction in the setting of femoroacetabular impingement syndrome (FAIS) and labral tears.

METHODS

A systematic review of the PubMed, Embase, and Cochrane databases was performed in May 2020 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Articles were included in the analysis if they compared PROs between a labral repair and labral reconstruction cohort. For all PROs, the standardised mean difference (SMD) was calculated to compare the effect size of labral repair and labral reconstruction.

RESULTS

10 comparative studies, with 582 reconstruction cases and 631 repair cases, were included in this analysis. The mean age for the reconstruction and the repair groups ranged from 27.0 years to 52.6 years and 27.5 years to 47.0 years, respectively. The mean follow-up for the reconstruction and the repair groups ranged from 24.0 months to 66.0 months and 24.0 months to 71.0 months, respectively. The modified Harris Hip Scores (mHHS) was favourable in 8 reconstruction studies (range 80.4-95.0) and 9 repair studies (range 84.1-93.0). Average NAHS scores for the repair and reconstruction cohorts ranged from 77.9-88.6 and 73.9-92.4, respectively. Additionally, the effect sizes regarding NAHS and mHHS scores were large (SMD > 0.8) in both the reconstruction and repair groups for the majority of studies. Finally, reconstruction patients underwent a subsequent total hip arthroplasty (THA) at a slightly higher rate.

CONCLUSIONS

In the setting of FAIS and labral tears, patients who underwent hip arthroscopy may expect significant improvement in PROs at short-term follow-up with either labral repair or labral reconstruction. Although, not statistically significant, the repair group trended towards higher scores and exhibited a lower risk of conversion to THA.

Acetabular labral tears in the adolescent athlete: results of a graduated management protocol from therapy to arthroscopy

This study sought to determine outcomes of a graduated management protocol from therapy to arthroscopy for adolescents presenting with hip pain and an associated acetabular tear. Thirty-seven hips with an MRI confirmed labral tear were prospectively enrolled in a graduated management protocol created for adolescents. The protocol began with activity modification and focused physical therapy. Patients with persistent symptoms were offered an intraarticular corticosteroid injection. Those with continued symptoms were treated with arthroscopic surgery. The modified Harris hip score (mHHS) and nonarthritic hip score (NAHS) were recorded at the initial visit. Patients were contacted by telephone at 1, 2, and 5 years from enrollment for repeat assessment with mHHS and NAHS. At presentation, the mean mHHS and NAHS for the entire cohort was 66.4  ±  11.4 and 70.2  ±  12.6, and these values improved significantly to 89.3  ±  10.6 and 87.0  ±  11.4 at a mean follow-up of 35.7  ±  18.3 months (range 11.7-64.4 months). Forty-two percent of hips were managed with physical therapy and activity modifications alone, 28% of hips progressed to a steroid injection but did not require surgery, and 31% required arthroscopic intervention. Seventy-three percent of hips treated with activity modification alone, 80% treated with an injection, and 82% of hips treated with arthroscopic repair met the minimal clinically significant difference (MCID) (P = 0.859). At an average of 36 months follow-up, the majority (78%) of adolescent patients with an acetabular labral tear will achieve the MCID utilizing a graduated management protocol.

Restoration of Labral Function in Primary Hip Arthroscopy From Labral Repair to Labral Reconstruction

The function and importance of the labrum in hip biomechanics has been established. A labral tear is the most common pathology in patients undergoing hip arthroscopy, and adequate management is critical for favorable outcomes. Although labral debridement was initially performed for arthroscopic labral tear management, there has been a shift toward labral restoration techniques. Currently, restoration with labral repair remains the gold standard for labral tear treatment, particularly in the primary setting. When compared to labral debridement, the literature has shown that labral repair has more favorable outcomes. Irreparable labral tears, although unusual in the primary setting, present a challenge. Labral reconstruction and augmentation are recent advancements in this scenario of hip arthroscopy that can help restore labral function. Two alternatives of labral reconstruction have been described: segmental and circumferential. Clinical data for segmental labral reconstruction has reported good outcomes at short-, mid-, and long-term follow-up. Similarly, arthroscopic circumferential reconstruction has shown good to excellent results at short-term follow-up. As the name suggests, only a segment of the labrum is reconstructed during segmental reconstruction. In a circumferential reconstruction, the entire labrum is taken down from the most anterior to the most posterior aspect of the transverse acetabular ligament and is reconstructed using an auto or allograft. A benefit of circumferential labral reconstruction is the removal of the entire damaged labral tissue, a potential source of pain. However, there is no clear evidence that demonstrates the superiority of one method over the other. Labral graft reinforcement via tissue augmentation or labral augmentation is an interesting option because it preserves the native chondrolabral junction. Labral augmentation can also be used for hypoplastic labrum that intraoperatively demonstrates a deficient suction-seal.

Circumferential and Segmental Arthroscopic Labral Reconstruction of the Hip Utilizing the Knotless Pull-Through Technique with All-Suture Anchors

Appropriate labral tear management is one of the principal priorities of hip-preservation surgery. The labrum's role in the stability and biomechanics of the hip and preservation of the suction seal has been thoroughly demonstrated. Favorable patient-reported outcomes with labral reconstruction and, more recently, labral augmentation have shown that these are viable reconstructive procedures in the setting of irreparable labra. A wide variety of grafts have been used for these advanced labral restoration techniques. The present Technical Note will describe a detailed arthroscopic circumferential labral reconstruction using the pull-through technique with knotless all-suture anchors. The benefits of such can be applied to both segmental and circumferential labral reconstruction procedures, as well as labral augmentation, based on the intraoperative findings and preference of the surgeon.

An Inverted Acetabular Labrum Is Predictive of Pavlik Harness Treatment Failure in Children With Developmental Hip Dysplasia

INTRODUCTION

The failure rate of Pavlik harness treatment for developmental dysplasia of the hip (DDH) has been reported as high as 55%. The purpose of this study is to investigate the effect of an inverted acetabular labrum on outcomes of Pavlik harness treatment for DDH.

METHODS

A retrospective review was conducted on DDH patients at a tertiary care pediatric hospital from 2004 to 2016. DDH patients that underwent index treatment with Pavlik harness and had minimum 12 months follow-up were included. Medical charts were reviewed for demographics, treatment, and outcomes. Outcomes were compared between patients with an inverted labrum versus those without an inverted labrum.

RESULTS

A total of 156 patients with 229 dysplastic hips were included. The mean age at initiation of Pavlik harness treatment was 1.9±1.4 months and mean follow-up was 37.7±23.0 months. Bilateral DDH was diagnosed in 46% (73/156) of patients. In all, 37% (75/229) of hips failed Pavlik harness index treatment. Second-line treatment was rigid hip abduction bracing in 91% (68/75) of hips, closed reduction in 5% (4/75) of hips, and open reduction in 4% (3/75) of hips. An inverted labrum was present in 10% (22/229) of all hips. The incidence of Pavlik harness treatment failure was 91% (20/22) in the inverted labrum group compared with 27% (55/207) in the control group (P<0.001). Closed or open reduction was required in 86% (15/22) of the inverted labrum group compared with 3% (7/207) of hips in the control group (P<0.001). The incidence of avascular necrosis was 18% (4/22) in hips with an inverted labrum compared with 0.4% (1/207) in the control group (P<0.001).

CONCLUSIONS

In children with DDH undergoing index treatment in a Pavlik harness, the presence of an inverted acetabular labrum is strongly predictive of treatment failure. Dysplastic hips with an inverted labrum also have a significantly higher risk of requiring closed or open reduction and developing avascular necrosis compared with those without an inverted labrum.

LEVEL OF EVIDENCE

Level III.

Arthroscopic Circumferential Acetabular Labral Reconstruction for Irreparable Labra in the Revision Setting: Patient-Reported Outcome Scores and Rate of Achieving the Minimal Clinically Important Difference at a Minimum 2-Year Follow-up

BACKGROUND

There is a paucity in the literature reporting patient-reported outcome (PRO) scores and the minimal clinically important difference (MCID) after revision hip arthroscopic surgery with circumferential labral reconstruction.

PURPOSE

To report minimum 2-year PRO scores and the rate of achieving the MCID in patients who underwent revision hip arthroscopic surgery with circumferential labral reconstruction in the setting of irreparable labral tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data were retrospectively reviewed for all patients who underwent revision hip arthroscopic surgery between February 2016 and November 2017. Patients were included if they had undergone circumferential labral reconstruction and had preoperative and postoperative scores for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score Sport-Specific Subscale (HOS-SSS), International Hip Outcome Tool (iHOT-12), 12-Item Short Form Health Survey physical and mental components (SF-12 P and SF-12 M, respectively), Veterans RAND 12-Item Health Survey physical and mental components (VR-12 P and VR-12 M, respectively), and visual analog scale (VAS) for pain. Exclusion criteria were Tönnis grade >1, Legg-Calve-Perthes disease, slipped capital femoral epiphysis, fractures, hip dysplasia, or revision labral treatment different from circumferential labral reconstruction. The MCID was calculated. Secondary surgical procedures were documented.

RESULTS

A total of 26 hips (26 patients; 61.5% female) were included. The mean age and body mass index were 33.2 ± 10.4 years and 25.5 ± 4.9, respectively. Significant improvements were reported for the mHHS (17.0 ± 19.5; P = .0002), NAHS (17.9 ± 16.7; P < .0001), HOS-SSS (21.7 ± 23.1; P = .0005), VAS (-2.2 ± 3.0; P = .006), iHOT-12 (25.8 ± 32.5; P = .0007), SF-12 P (8.5 ± 11.2; P = .001), and VR-12 P (8.9 ± 11.6; P = .001). Rates of meeting the MCID for the mHHS, NAHS, HOS-SSS, iHOT-12, and VAS were 76.9%, 80.0%, 65.0%, 62.5%, and 69.2%, respectively. No case of re-revision arthroscopic surgery was documented, but 1 case of conversion to total hip arthroplasty was documented at 38.6 months.

CONCLUSION

In the setting of revision hip arthroscopic surgery and irreparable labral tears, circumferential labral reconstruction resulted in significant improvements in all PRO and VAS scores at a minimum 2-year follow-up with a high rate of achieving the MCID.

Clinical Outcomes of Hip Arthroscopy for Hip Labrum Calcification in Young and Middle-Aged Patients

OBJECTIVE

To investigate the methods and outcomes of hip arthroscopy for hip labrum calcification, and to discuss the clinical, imaging, and intraoperative findings of hip labrum calcification.

METHODS

This is a therapeutic case series study. From January 2015 to June 2018, 15 patients who met the inclusion and exclusion criteria were followed up for at least 2 years for an analysis on the outcomes of arthroscopy in the treatment of hip labrum calcification and the clinical, imaging, and intraoperative findings of the patients. There were eight males and seven females, with an average age of 38.9 ± 8.8 years (range, 23-50 years). The visual analog scale (VAS), the modified Harris hip score (mHSS), and the international hip outcome tool (iHOT-12) were used to evaluate the outcomes of surgery.

RESULTS

A total of 15 patients were followed up for at least 2 years (28.1 ± 2.9 months). The average calcified volume was 118.0 mm³ (range, 19.4-609.2 mm³ ) and calcified volume was related to the preoperative hip function score. Thirteen patients had pain in the groin area (86.7%). Labrum calcifications were located (according to the clock distribution) as follows: 14 patients were anterior and superior (11:00-3:00); 12 cases of femoroacetabular impingement (FAI) were observed during operation, including five cases of pincer type, two cases of cam type, and five cases of mixed type. VAS pain score means were 7.73 ± 1.28 before surgery, decreasing to 2.0 ± 0.89 and 1.73 ± 0.79 at 1 and 2 years post-surgery, respectively. mHSS scores were 57.40 ± 6.23 before surgery and 82.10 ± 4.76 and 83.18 ± 4.07, 1 and 2 years post-surgery, respectively; iHOT-12 mean score pre-surgery was 37.67 ± 4.85, increasing to 67.64 ± 5.30 and 72.18 ± 4.49, 1 and 2 years post-surgery, respectively. Compared with preoperative values, postoperative VAS, mHSS, and iHOT-12 scores were significantly improved (P < 0.01); iHOT-12 scores also significantly decreased from 1 to 2 years postoperatively (P = 0.034). No patient had complications.

CONCLUSION

Hip arthroscopy is an effective method for the treatment of hip labrum calcification. The size of calcification influenced preoperative symptoms and function. Long-term irritation from FAI may be one important cause of labrum calcification.

Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability

Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the static stabilizers of the hip joint. Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. The patient may present with a painful limp and recurrent subluxation sensation in the affected hip joint. Revision hip arthroscopy in this scenario is generally complicated, and it is not uncommon for all the soft-tissue stabilizers to be compromised. The labrum, ligamentum teres (LT), and capsule of the hip joint are often so damaged that reparation is not an option. Reconstruction of the torn LT is an established method to add secondary stability while addressing the labral pathology in the hip joint with microinstability. Concomitant reconstruction of all the static restraints has yet to be described addressing triple instability. This Technical Note presents a stepwise approach, including tips and pearls, for arthroscopic triple reconstruction of the labrum, LT, and capsule. We believe this method is a safe and reproducible way to effectively treat gross hip instability in young patients.

Determining Reliability of Arthroscopic Classifications for Hip Labral Tears

OBJECTIVE

Evaluate interobserver and intraobserver reliability of hip arthroscopic classifications for labral tears.

DESIGN

Retrospective diagnostic study of nonconsecutive patients.

SETTING

Institutional study.

PATIENTS

From a database of 278 hip arthroscopy videos for treatment of femoroacetabular impingement, 70 videos were chosen by simple random sampling. Exclusion criteria included presence of radiological arthrosis (Tonnis > 2), previous hip surgery, inadequate lesion palpation, poor image quality, and refusal to participate in the study. The final sample included 60 videos.

INTERVENTIONS

Four hip surgeons evaluated the videos twice at 1-month intervals and classified the lesions according to Lage, Seldes, and Beck classifications for hip labral tears.

MAIN OUTCOME MEASURES

Interobserver and intraobserver reliability with the percent of agreement and weighted Cohen kappa values.

RESULTS

Patients had a mean age of 33 years (SD, 7; range, 18-47 years), and 32 (53%) were men. Femoroacetabular impingement types included combined (CAM and pincer) in 31 (52%), CAM in 27 (45%), and pincer in 2 (3%). For interobserver reliability, the average weighted kappa values were 0.68, 0.65, and 0.78 for the Lage, Seldes, and Beck classifications, respectively. For intraobserver reliability, the mean weighted kappa values were 0.87, 0.64, and 0.93 for the Lage, Seldes, and Beck classifications, respectively.

CONCLUSIONS

Beck classification had the highest average values for interobserver and intraobserver agreements. Lage, Seldes, and Beck scores for acetabular labrum tears showed substantial interobserver agreement. In the intraobserver evaluation, the Seldes system presented substantial agreement, whereas Lage and Beck classifications were considered excellent agreement.

Graft Options in Hip Labral Reconstruction

PURPOSE OF REVIEW

The last decade has seen a boom in hip arthroscopy with refined indications. Improved understanding of pathoanatomy and disease progression has allowed for the development of advanced techniques. Labral reconstruction has been developed to substitute a non-functional or absent labrum. It has become an important technique in the armamentarium of high-volume arthroscopic hip surgeons.

RECENT FINDINGS

Basic science studies have improved understanding of hip biomechanics in the presence and absence of a labrum with a labral reconstruction allowing for reconstitution of normalcy. Current techniques have shown success with autograft and allograft tissue options. While autograft tissue allows for easy access intra-operatively and maintains patient biology, donor site morbidity is possible. Allografts negate donor site morbidity and allow for an abundance of tissue but can be resource-intensive and face availability concerns. Recent studies support outcomes of labral reconstructions using both autograft and allograft. Promising results have also allowed for performing labral reconstruction in a primary setting. Labral reconstruction can be successfully performed using both autograft and allograft. Patient biology should be respected, and native hip biomechanics restored. The literature is plentiful for appropriate surgical decision-making allowing the surgeon with multiple graft choices depending on training, experience, and resources.

Decreased Hip Labral Width Measured via Preoperative Magnetic Resonance Imaging Is Associated With Inferior Outcomes for Arthroscopic Labral Repair for Femoroacetabular Impingement

PURPOSE

To determine the association between labral width as measured on preoperative magnetic resonance imaging (MRI) and hip-specific validated patient self-reported outcomes at a minimum of 2 years' follow-up.

METHODS

We performed an institutional review board-approved retrospective review of prospectively gathered hip arthroscopy patients from 2010 to 2017. The inclusion criteria were defined as patients aged 18 to 65 years with radiographic evidence of femoroacetabular impingement who underwent a primary labral repair and had a minimum of 2 years' clinical follow-up. The exclusion criteria were defined as inadequate preoperative imaging, prior hip surgery, Tönnis grade 1 or higher, or lateral center-edge angle lower than 25°. An a priori power analysis was performed. MRI measurements of labral width were conducted by 2 blinded, musculoskeletal fellowship-trained radiologists at standardized "clock-face" locations using a previously validated technique. Outcomes were assessed using the Harris Hip Score (HHS), modified Harris Hip Score (mHHS), and Non-arthritic Hip Score (NAHS). For the mHHS, scores of 8 and 74 were used to define the minimal clinically important difference and patient acceptable symptomatic state, respectively. Patients were divided into groups by a labral width less than 1 SD below the mean (hypoplastic) or widths above 1 SD below the mean. Statistical analysis was performed using linear and polynomial regression; the Mann-Whitney U, χ², and Fisher exact tests; and intraclass correlation coefficient testing.

RESULTS

A total of 103 patients (107 hips) met the inclusion criteria (mean age, 39.4 ± 17 years; body mass index, 25.0 ± 4; 51% right sided; 68% female patients; mean follow-up, 76.5 ± 19.1 months [range, 30.0-113.0 months]). Mean labral width at the 11:30 clock-face position (indirect rectus), 3-o'clock position (psoas U), and 1:30 clock-face position (point halfway between the 2 aforementioned positions) was 7.1 ± 2.2 mm, 7.0 ± 2.0 mm, and 5.5 ± 1.9 mm, respectively. Intraclass correlation coefficient agreements were good to excellent between readers at all positions (0.83-0.91, P < .001). The preoperative HHS, mHHS, and NAHS were not statistically significantly different (P > .05) between the 2 groups. Sex, laterality, and body mass index were not predictive of outcomes (P > .05). The postoperative HHS, mHHS, and NAHS were found to be significantly lower in the hypoplastic group at each location tested (P < .01), including the mHHS at the 11:30 clock-face position (69 vs 87), 3-o'clock position (70 vs 87), and 1:30 clock-face position (71 vs 87). The proportion of patients with hypoplastic labra who reached the minimal clinically important difference was significantly lower (P < .001) at the 11:30 clock-face position (50% vs 91%), 3-o'clock position (56% vs 90%), and 1:30 clock-face position (58% vs 91%) in comparison to the non-hypoplastic labrum group. The proportion of patients with hypoplastic labra above the patient acceptable symptomatic state was significantly lower (P < .001) at the 11:30 clock-face position (44% vs 83%), 3-o'clock position (37.5% vs 84%), and 1:30 clock-face position (42% vs 85%) in comparison to the non-hypoplastic labrum group. Linear regression modeling was not significant at any position (P > .05). Polynomial regression was significant at the 11:30 clock-face position (R² = 0.23, P < .001), 3-o'clock position (R² = 0.17, P < .001), and 1:30 clock-face position (R² = 0.26, P < .004).

CONCLUSIONS

Hip labral width less than 1 SD below the mean measured via preoperative MRI was associated with significantly worse functional outcomes after arthroscopic labral repair and treatment of femoroacetabular impingement. The negative relation between labral width and outcomes may be nonlinear.

LEVEL OF EVIDENCE

Level IV, case series with subgroup analysis.

[Research progress in arthroscopic treatment of acetabular labrum injury]

Objective

To review the surgical methods of arthroscopy in the treatment of acetabular labrum injury, and to provide reference for clinical treatment.

Methods

The literature about the surgical methods and clinical results of hip arthroscopy in the treatment of acetabular labrum injury was reviewed and analyzed.

Results

In the early stages of hip arthroscopy, the removal of the torn labrum is the primary treatment option. The current principles of treatment are based on the specific circumstances of a torn labrum, including acetabular labrum debridement, acetabular labrum repair, acetabular labrum reconstruction, and acetabular labrum augmentation.

Conclusion

Hip arthroscopy has become the preferred technique for the treatment of acetabular labrum injury. Labral repair is still the first choice, and labral reconstruction is used when acetabular labrum injury cannot be repaired.

Femoroacetabular Impingement and Acetabular Labral Tears - Part 1: Pathophysiology and Biomechanics

Femoroacetabular impingement (FAI) is an important cause of hip pain, and the main etiology of hip osteoarthritis in the young population. Femoroacetabular impingement is characterized by subtle alterations in the anatomy of the acetabulum and proximal femur, which can lead to labrum tearing. The acetabular labrum is essential to the stability of the hip joint. Three types of FAI were described: cam (anespherical femoral head), pincer (acetabular overcoverage) and mixed (characteristics of both cam and pincer). The etiology of FAI is related to genetic and environmental characteristics. Knowledge of this condition is essential to adequately treat patients presenting with hip pain.

Teamwork in hip preservation: the ISHA 2019 Annual Scientific Meeting

Hip preservation surgery is now an established part of orthopedic surgery and sports medicine. This report describes the key findings of the 11th Annual Scientific Meeting of International Society for Hip Arthroscopy-the International Hip Preservation Society-in Madrid, Spain from 16 to 19 October 2019. Lectures, seminars and debates explored the most up-to-date and expert views on a wide variety of subjects, including: diagnostic problems in groin pain, buttock pain and low back pain; surgical techniques in acetabular dysplasia, hip instability, femoroacetabular impingement syndrome, labral repair and reconstruction, cartilage defects, adolescent hips and gluteus medius and hamstring tears; and new ideas about femoral torsion, hip-spine syndrome, hip capsule surgery, impact of particular sports on hip injuries, registries, robotics and training for hip preservation specialists. Surgeons, sports physicians, radiologists and physiotherapists looking after young people with hip problems have an increasingly sophisticated armoury of ideas and techniques with which to help their patients. The concept of hip preservation has developed incredibly fast over the last decade; now it is clear that the best results can only be achieved by a multidisciplinary team working together. The 2020s will be the decade of 'Teamwork in Hip Preservation'.

Circumferential Labral Reconstruction for Irreparable Labral Tears in the Primary Setting: Minimum 2-Year Outcomes With a Nested Matched-Pair Labral Repair Control Group

PURPOSE

(1) To report minimum 2-year patient-reported outcome (PRO) scores of primary circumferential acetabular labral reconstruction using anterior tibialis allograft and the knotless pull-through technique in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare these PROs with a matched-pair primary labral repair group.

METHODS

Data were prospectively collected and retrospectively reviewed. Patients were included if they underwent primary circumferential labral reconstruction with anterior tibialis tendon allograft during February 2016 to April 2017 for irreparable labral tears and FAIS and had preoperative and minimum 2-year follow-up for modified Harris Hip Score (mHHS), Hip Outcome Score-Sport-Specific Subscale, Non-arthritic Hip Score, International Hip Outcome Tool 12 (iHOT-12), 12-Item Short Form Health Survey physical component and mental component, Veterans RAND 12-Item Health Survey physical component and mental component, and visual analog scale for pain. The exclusion criteria were previous ipsilateral hip conditions or surgical procedures, Tönnis grade 2 or higher, or dysplasia (lateral center-edge angle ≤ 18°). Labral tears were considered irreparable if the labrum appeared (1) to be mostly or completely calcified and (2) to be inadequate (nonviable) and not amenable for labral repair. The reconstruction group was matched 1:3 based on age, sex, and body mass index to a benchmark control group of hips undergoing labral repair from the same period. The minimal clinically important difference and patient acceptable symptomatic state for the mHHS and iHOT-12 score were calculated.

RESULTS

A total of 37 hips (37 patients) underwent circumferential labral reconstruction. There were 19 female patients (51.4%) and 18 male patients (48.6%). The mean age was 45.6 ± 11.6 years, and the average body mass index was 27.1 ± 5. At minimum 2-year follow-up, the circumferential labral reconstruction group showed statistically significant improvements in the mHHS, Non-arthritic Hip Score, Hip Outcome Score-Sport-Specific Subscale, iHOT-12 score, and visual analog scale score. All hips in the reconstruction group were successfully matched to 111 labral repair hips. At latest follow-up, improvements in all PROs between the 2 groups were comparable. The revision rates were 0% and 3.6% in the reconstruction and repair groups, respectively.

CONCLUSIONS

After primary hip arthroscopy, primary circumferential labral reconstruction using anterior tibialis allograft and the knotless pull-through technique in the setting of FAIS and irreparable labral tears resulted in significant improvements in several PROs at minimum 2-year follow-up and high patient satisfaction. Primary circumferential labral reconstruction reached comparable functional outcomes to those of a benchmark matched-pair primary labral repair control group.

LEVEL OF EVIDENCE

Level III, case-control study.