Preoperative predictors of outcome in the arthroscopic treatment of femoroacetabular impingement.

AIMS The aim of this study was to establish preoperative factors associated with a good outcome in the surgical treatment of femoroacetabular impingement. METHODS A prospective study including 253 consecutive patients (280 hips) was carried out. We defined a "good" score as one which had either a 20 point improvement from preoperative to 12 months postoperative follow-up, or a score of over 80 points at 12-month follow-up in either the Non Arthritic Hip Score (NAHS) or Modified Harris Hip Score (MHHS). We analysed 9 potential predictors of 12-month postoperative outcome: patient age, gender, BMI, surgery type (primary/revision), preoperative anxiety level, preoperative labro-chondral damage, operative side, patients belonging to the armed forces and patients being treated under the workers compensation scheme. We used logistic regression (multivariable, adjusted) and, Fisher's exact test and student t test (bivariate, unadjusted) to analyse the data. RESULTS A strong association between workers' compensation status and not achieving a good outcome following arthroscopic surgery for femoroacetabular impingement (odds ratio 3.84, 95% CI, 0.13-0.51, P<0.0001) was found. A negative effect on postoperative outcome was also observed with increased BMI, although this association was modest (odds ratio 1.06, 95% CI, 0.87-0.99 p = 0.03). Patients with a higher preoperative score did better at 12 months than the rest of the cohort. CONCLUSIONS The data from this study may be useful for both patient and physician to consider when deciding on a suitable treatment in potential surgical candidates suffering from femoroacetabular impingement.