Improved Midterm Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome in the Setting of a Previous Slipped Capital Femoral Epiphysis.

Abstract

Background: Hip arthroscopy after in situ fixation of a slipped capital femoral epiphysis (SCFE) is used to treat postoperative disability that develops from metaphyseal cam deformity after pinning. Short-term follow-up has demonstrated excellent outcomes in patients treated for SCFE with subsequent hip arthroscopy. Midterm follow-up of these patients has been sparse and rarely reported in the literature.

Purpose: To evaluate the midterm clinical and functional outcomes of patients undergoing hip arthroscopy after SCFE in situ fixation.

Study design: Case series; Level of evidence, 4.

Methods: Patients with SCFE who underwent subsequent hip arthroscopy for femoroacetabular impingement (FAI) were enrolled in a prospective database. Inclusion criteria were a primary diagnosis of residual post-SCFE deformity and subsequent surgical treatment for FAI >1 year before the start date of the study. Patients were excluded if they were unable to be contacted. Participants were sent a survey that included physical function (Patient-Reported Outcomes Measurement Information System [PROMIS]) and Likert-style questions assessing disability and satisfaction. Patient charts were retrospectively reviewed for patient characteristics, visual analog scale (VAS) pain scores, and a modified Harris Hip Score (mHHS) from the postfixation but prearthroscopy period.

Results: Of the 63 patients receiving hip arthroscopy after treatment for SCFE, 41 patients met the inclusion criteria and 34 completed the midterm follow-up survey (54.0% response rate). The mean duration of follow-up was 6.17 years. Patient subjective outcomes demonstrated that 88.3% of patients reporting being satisfied or very satisfied with their surgical result. The mean preoperative baseline mHHS was 67.43, indicating poor functional status. The mean midterm follow-up PROMIS-PF T score for this cohort was 50.81, indicating a slight overall improvement for the study cohort's functional status when compared with the general population. The mean VAS pain score at rest was 5.09 preoperatively and 1.91 at midterm follow-up. The mean postarthroscopy iHOT-12 score was 68.27 (SD, 28.58), indicating greater quality of life postoperatively, with 20 patients (59%) obtaining a Patient Acceptable Symptom State (PASS) and a revision rate of 15%.

Conclusion: The results of the first midterm follow-up of patients undergoing hip arthroscopy after surgical pinning of SCFE demonstrate improved functional and clinical objective outcomes compared with preoperative scores. These patients demonstrated poor functional status preoperatively but average or above-average functional status at the midterm follow-up postoperatively. Additionally, 20 patients (58.8%) obtained a PASS and a revision rate of 15%.

Clinical relevance: Arthroscopic treatment of post-SCFE FAI reported at short-term follow-up persists into the midterm follow-up period with hip function equivalent to age-matched population norms.