To evaluate early clinical outcomes and complication rates of the outside-in extracapsular approach for the treatment of femoroacetabular impingement (FAI) and to assess the effect of capsular closure on the functional outcome.

A consecutive series of hip arthroscopies performed for surgical treatment of FAI using the Ouside-In approach with minimum 2 years follow-up were assessed. Any complications during early, intermediate or long-term follow were identified and recorded. Linear regression models were used to estimate the influence of capsular closure on the functional outcome.

Sixty-four hips in 57 patients were analyzed at the time of final follow-up of 34.17 months (range 24 to 53). Functional outcome measurements showed an improvement from the preoperative to the last follow-up: 63.5±11.0 to 88.1±11.2 for mHHS, 63.1±13.8 to 86.4±13.4 for NAHS. All PROs showed a statistically significant improvement at final follow-up compared with preoperative levels. Capsular closure leads to a significantly improved clinical outcome (P>0.05). No major complications occurred. One case of postoperative tensor fascia latae atrophy was documented.

Hip arthroscopy in the management of FAI with an extra-articular starting point (Outside-In) is a safe technique with functional results and postoperative morbidity comparable to previous reported techniques. Side to side capsular closure at the end of the procedure might positively affect the final functional outcome.