Introduction: Hip dysplasia is a common cause of hip pain in young adults. Pelvic osteotomy (PO) techniques are the gold standard for treating symptomatic patients, albeit technically demanding. This study aimed to (1) evaluate the 90-day complication rate, and (2) investigate the frequency, timing and indication for reoperations following primary PO procedures.

Methods: We performed a retrospective observational study analysing national data from the Hospital Episode Statistics (HES) database in England. We identified all patients aged over 14 who underwent PO in NHS hospitals between April 2010 and March 2023. All PO procedures and reoperations were identified using relevant OPCS-4 codes. We evaluated patient demographics, 90-day readmission rate for complications, and reoperation rates for ipsilateral metalwork removal, revision PO, hip arthroscopy (HA), and conversion to total hip replacement (cTHR). Descriptive statistical analyses were performed to calculate frequencies and mean time to reoperations. The lifetime risk of cTHR was calculated using a life table approach and cumulative probability method.

Results: This study included 1,348 POs (mean age: 28.7±9.1 years, 89.5% female). The mean hospital stay was 5.4±3.9 days, with a 90-day readmission rate of 0.52% at a mean of 51.0±17.2 days. The most common causes for 90-day readmission were infection (0.22%) and reoperation (0.15%). The 90-day rate of pulmonary embolism and deep vein thrombosis was 0.074%. One patient died within 90 days. Overall, 810 patients (60.1%) were readmitted for a subsequent hip procedure at a mean of 2.12±1.90 years. Metalwork removal was required in 616 patients (45.7%) at a mean of 1.70±1.19 years. Readmission rates for revision PO, HA, and cTHR, were 4.23%, 4.15% and 6.01% at a mean of 2.89±0.82, 2.91±2.28, and 5.24±3.08 years respectively. The cumulative survival with THR as the endpoint was 92.8% over the 13-year study period.

Conclusions: This study highlights a low 90-day complication rate following primary PO, but a high reoperation rate, mainly for metalwork removal. We provide the most up-to-date report of revision PO, HA and conversion to THR rates in England. These findings provide valuable insights that can facilitate informed decision-making, expectation-setting, and post-operative planning, also establishing a benchmark for future quality improvement.