Function and osteoarthritis progression after arthroscopic treatment of femoro-acetabular impingement: A prospective study after a mean follow-up of 4.6 (4.2–5.5) years

Abstract

BackgroundOutcomes after arthroscopic femoro-acetabular impingement (FAI) surgery are promising in the short-term but have rarely been evaluated in the mid-term (e.g., about 5years). Here, our objectives were to obtain mid-term data on functional and radiographic outcomes, to identify prognostic factors, and to determine the mid-term rate of arthroplasty revision with the associated risk factors. HypothesisWe hypothesized that the results of arthroscopic FAI surgery were sustained over time. Materials and methodsWe conducted a prospective multi-surgeon study of 53 Tönnis grade 0 or 1 hips treated arthroscopically for symptomatic FAI (23 cam, 10 pincer, and 20 mixed deformities). We obtained short-term (10months) and mid-term (4.6years) data on the functional outcome (WOMAC and satisfaction scores), proportion of patients without revision arthroplasty, and development of osteoarthritis (graded using the Tönnis classification). ResultsIn the patients without revision arthroplasty, the WOMAC score improved significantly (P<0.01) from baseline (61.4±15.6) to 10months (84.2±15.6) and last follow-up (85.2±15.5) but remained unchanged between the two postoperative time points, confirming the stability of the results. The proportion of satisfied patients was 79% after 10months and 68% (36/53) at last follow-up (NS). Osteoarthritis developed in 13/35 (37%) hips for which radiographs were obtained at last follow-up. At last follow-up, 46/53 hips (87%; 95%CI, 78–96) did not required revision surgery; arthroplasty was required in the 7 remaining hips. The main prognostic factor was the preoperative osteoarthritis Tönnis grade: at last follow-up, compared to Tönnis grade 0 hips, Tönnis grade 1 hips had lower WOMAC scores (77 vs. 88), lower satisfaction rates (50% versus 77%), a higher rate of osteoarthritis progression (57% versus 24%), and a higher rate of arthroplasty (33.3% versus 2.9%). DiscussionOur results are consistent with published data. The outcomes of arthroscopic FAI surgery are sustained over time and the preoperative osteoarthritis status is the main predictor of mid-term outcomes. Level of evidenceIV, prospective cohort study.