Multivariable Cox proportional hazards estimates for predictors of conversion from high tibial osteotomy to total knee replacement
| Predictor | Adjusted HR (95% CI) |
|---|---|
| Radiographic severity (Kellgren and Lawrence grade) | |
| Mild to moderate* | Ref. |
| Moderate to severe* | 1.96 (1.12–3.45) |
| Preoperative alignment (mechanical axis angle),° | 1.05 (0.98–1.11) |
| Correction size, mm | 1.03 (0.95–1.12) |
| KOOS Pain subscale score (per 10 points)† | 0.85 (0.75–0.96) |
| Sex | |
| Male | Ref. |
| Female | 1.67 (1.08–2.58) |
| Age (per 10 yr) | 1.50 (1.17–1.93) |
| Body mass index (per 5 kg/m2) | 1.31 (1.12–1.53) |
| Year of surgery | 1.03 (0.94–1.12) |
Note: CI = confidence interval, HR = hazard ratio, KOOS = Knee injury and Osteoarthritis Outcome Score, Ref. = reference category. We adjusted variance for staged bilateral osteotomies using robust sandwich estimators.
↵* Kellgren and Lawrence grade mild to moderate ≤ 2; moderate to severe = 3 or 4.
↵† KOOS: 0 indicates extreme knee symptoms; 100 indicates no knee symptoms.