Does hip preservation fellowship training flatten the learning curve associated with periacetabular osteotomy?

Abstract The Bernese periacetabular osteotomy (PAO) has been associated with a significant learning curve, with the majority of serious complications reported during the first 20–50 independent procedures. Our aim was to assess whether hip preservation fellowship training flattens the PAO learning curve with respect to complication profiles and 1-year patient-reported outcome measures (PROM). The clinical records of the first 50 PAOs (47 patients, median age 23.5 years) performed by a single surgeon after completion of a 12-month hip preservation fellowship programme were reviewed. The first 25 PAOs were compared with the second 25 PAOs with respect to complication profiles and PROM (modified Harris Hip Score, University of California Los Angeles activity score, pain visual analogue scale) at 12 months post-operatively. There were no significant between-group differences in demographic variables or pre-operative PROM. Twelve months post-operatively, no patients had experienced a major complication (Clavien–Dindo grades III–V). Twenty-three (46%) patients experienced at least one minor complication (grades I–II); 13 (52%) in the first group and 10 (40%) in the second group (no significant difference, P = 0.57). The most common complications were lateral femoral cutaneous nerve neuropraxia 14 patients (28%) and allogenic blood transfusion 7 patients (14%). There were no significant between-group differences with respect to 1-year post-operative PROM or post-operative change in PROM (all P 0.05). Although it is difficult to definitively conclude that hip preservation fellowship training is solely responsible for the reassuring outcomes in our series, we believe that such training can significantly flatten the learning curve associated with the Bernese PAO.