Intraoperative Findings and Clinical Outcomes Associated With Arthroscopic Management of Subspine Impingement: A Propensity-Matched, Controlled Study
Purpose: (1) To investigate intra-articular damage in the hip joint associated with subspine impingement (SSI); (2) to evaluate clinical outcomes of arthroscopic treatment of hips with SSI; and (3) to compare the findings and outcomes to a control group without SSI.
Methods: Eligible patients had arthroscopic treatment for femoroacetabular impingement (FAI) concurrent with SSI between January 2015 and December 2017. Inclusion criteria consisted of preoperative and minimum 2-year patient-reported outcomes and preoperative measurements for Tönnis, lateral center edge angle, and alpha angle. Included patients were propensity-matched in a 1:3 ratio to patients who had FAI without SSI. Patient-reported outcomes were compared between groups. Minimal clinically important difference was calculated for modified Harris Hip Score (mHHS) and Hip Outcome Score-Sports Specific Subscale (HOS-SSS).
Results: Fifty SSI cases were matched to 150 patients who had FAI without SSI. A greater proportion of the SSI cohort required labral reconstruction (P = .010). The size and locations for labral tears and chondral defects were comparable between groups (P > .05). Both groups demonstrated similar minimum 2-year outcomes for mHHS (P = .103), Nonarthritic Hip Score (P = .200), HOS-SSS (P = .119), visual analog scale (P = .231), international Hip Outcome Tool-12 (P =.300), Short Form-12 Mental (P = .426), Short Form-12 Physical (P = .328), Veterans RAND 12-Item Health Survey, Mental (P = .419), and Veterans RAND 12-Item Health Survey, Physical (P = .316). The percentage of patients achieving minimal clinically important difference for mHHS and HOS-SSS was similar (P > .05). Survivorship was 96.0% and 98.7% for the SSI and control cohorts at 2 years, respectively.
Conclusions: Arthroscopic treatment of hips with SSI with subspine decompression and concomitant treatment of labral tears and FAI yielded significant improvement in patients' outcomes, which compared favorably with the control group. SSI may correlate with more complex labral tears, not amenable to repair, and complete tears of the ligamentum teres. Other findings, such as location and size of intra-articular damage, were similar between the cohorts.
Level of evidence: III, case-control study.