Poster 222: Long-term Survivorship in Patients with Coxa Profunda and Acetabular Overcoverage: An Average 11-Year Follow-up After Hip Arthroscopy
Authors: Lee Jonathan S. , Dean Michael C. , Gillinov Stephen M. , Siddiq Bilal S. , Dowley Kieran S. , Torabian Kaveh A. , Martin Scott D. 
Published: August 2024

Objectives:

A prior study investigating 2-year patient-reported outcomes (PROs) following hip arthroscopy found that patients with coxa profunda and acetabular overcoverage report worse improvements yet similar overall outcomes scores. Regarding conversion to total hip arthroplasty (THA), however, patients with coxa profunda and overcoverage experienced significantly lower rates of survivorship (88.9% vs 100%; p = 0.04). When considering long-term outcomes, a recent study by Domb et al. found an 85.7% 10-year survivorship in patients after hip arthroscopy. Currently, there remains a paucity of literature on the effects of a deep acetabular socket and pincer-type femoroacetabular impingement on patient outcomes beyond 2-years follow-up. The objective of the present study was to report the long-term survivorship, revision surgery rate, patient satisfaction, pain level, and functional outcome scores in patients with coxa profunda and acetabular overcoverage following hip arthroscopy.

Methods:

This was an institutional review board-approved retrospective cohort study of patients with coxa profunda and a LCE angle > 40° who underwent hip arthroscopy for labral tears or FAI between November 2002 and May 2013. After failing conservative management, all patients were treated by a single surgeon and received the same capsulotomy technique and postoperative protocol. Patients with a minimum 8-years follow-up, complete PROs, the presence of coxa profunda as indicated by the acetabular wall projecting medial to the ilioischial line, and a LCE angle > 40° were included (Figure 1). Patients with severe osteoarthritis (Tönnis osteoarthritis grade > 2) or any previous hip surgeries were excluded. Patients meeting inclusion and exclusion criteria represented the overcoverage cohort (OC) and were matched 1:1 by sex, age within 8 years, body mass index (BMI) within 5 kg/m2, Tönnis grade, and labral treatment (repair vs debridement) to a matched control (MC) cohort that had a LCE angle between 25° and 40°. Collected postoperative outcomes include conversion to THA, revision hip arthroscopy, patient satisfaction, pain level (0-100), number of corticosteroid injections, and 6 PROs (modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Lower Extremity Functional Scale (LEFS), Hip Outcome Score (HOS)–Activities of Daily Living (HOS-ADL), HOS–Sports Specific subscale (HOS-SSS), and 33-item International Hip Outcome Tool (iHOT-33). Pearson χ2 test and Fisher exact test were used to compare categorical variables; two-sample t-tests were used to compare continuous variables. The threshold for statistical significance was set to 0.05. A survival analysis was performed using Kaplan-Meier curves. All statistical analyses were performed using Stata software (version 18.0; StataCorp).

Results:

A total of 38 patients in the OC cohort were 1:1 matched with 38 patients in the MC cohort. There were no differences in patient demographics including age, BMI, sex, Tönnis grade, labral treatment, follow-up duration, and Beck classification of labral damage or transition zone (chondrolabral junction) cartilage damage (Table 1). At an average of 11.3 years postoperatively (minimum 8-years follow-up), patients in the OC and MC cohort experienced similar rates of conversion to THA (OC: 11 [28.9%] vs MC: 6 [15.8%]; p = .169) and revision hip arthroscopy (OC: 4 [10.5%] vs MC: 1 [2.6%]; p = .165). The average time from primary hip arthroscopy to conversion to THA was 8.0 ± 6.5 years for OC and 3.7 ± 3.0 years for MC (p = .144) with the OC cohort converting to THA between 6.5 months to 17.14 years while the MC cohort ranged from 4.8 months to 7.8 years. Age at conversion to THA was 54.3 ± 8.0 years for the OC cohort and 59.0 ± 4.0 years for the MC cohort (p = .195). By Kaplan-Meier survival analysis, patients showed similar rates of survivorship (84.2%) at 12 years after hip arthroscopy; however, OC patients showed a 13.1% decrease in long-term survivorship (71.1%) between years 12 and 18 (Figure 2). Additionally, OC and MC patients showed similar levels of patient satisfaction, pain level, postoperative corticosteroid injections, and scores for all 6 PROs (Table 2).

Conclusions:

Patients with coxa profunda and overcoverage (LCE angle > 40°) showed similar levels of survivorship, revision arthroscopy, patient satisfaction, pain level, number of corticosteroid injections, and PROs to a 1:1 matched cohort of patients with normal acetabular coverage (LCE angle between 25° and 40°) at a minimum 8-years after primary hip arthroscopy. When analyzing long-term survivorship after 12 years, however, patients with overcoverage showed a 13.1% decrease in long-term survivorship (71.1%) compared to a matched control cohort. Overall, a greater focus on extended follow-up care after hip arthroscopy is needed to improve long-term survivorship in patients with a deep acetabular socket and pincer-type femoroacetabular impingement.