Osteotomies around the knee are associated with low short‐term adverse event and reoperation rates: A 25‐year national Hospital Episode Statistics analysis in England

PURPOSE: Osteotomy around the knee (OAK) is an established joint-preserving procedure. We sought to use large-scale registry data to examine the short-term reoperation and adverse outcome rates after OAK. METHODS: Data on high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) patients were extracted from UK National Health Service Hospital Episode Statistics (HES). Patients <16 or >80 years and bilateral cases within <6 months were excluded. Reoperations and serious complications within 90 days were identified using International Classification of Diseases, 10th Revision (ICD-10) and Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, 4th Revision (OPCS-4) codes. The primary outcome was reoperation rate at 90 days and 1 year; secondary outcomes were serious medical complications within 90 days, including pulmonary embolism (PE), myocardial infarction (MI), stroke, lower respiratory tract infection (LRTI), acute kidney injury (AKI), urinary tract infection (UTI) and neurovascular injury. Logistic regression was done to estimate odds for serious complications. RESULTS: A total of 24,947 osteotomies (18,871 HTO, 4490 DFO, 1586 doubles; 23,371 patients) were included (mean age: 41 years; 62% male; Charlson index 0: 80.42%). Within 90 days, 2.27% (95% confidence interval [CI] 2.08-2.47) underwent a reoperation, including 1.00% (95% CI 0.88-1.13) for infection. At 1 year, 7.26% (95% CI 6.93-7.61) of patients underwent at least one reoperation, including 2.11% for infection (95% CI 1.92-2.30, n = 486); at 1 year, 0.38% (95% CI 0.31-0.47) had undergone arthroplasty. Within 90 days, 1.95% (95% CI 1.78-2.13) experienced at least one adverse event. Specific serious complication rates included PE 0.39% (95% CI 0.32-0.47), MI 0.029% (95% CI 0.01-0.05), stroke 0.029% (95% CI 0.01-0.05) and AKI 0.35% (95% CI 0.28-0.43). Higher comorbidity index was consistently associated with higher rates of reoperation and adverse events. CONCLUSIONS: Knee osteotomy is a safe procedure performed in a predominantly young and healthy population, with low 90-day morbidity. Higher comorbidity index is the strongest predictor of serious complications. Female patients had a lower risk of reoperation but higher adverse event risks. These population-level findings will help inform consent discussions and may support future risk stratification. LEVEL OF EVIDENCE: Level I, prospective cohort.