| Failure | Non-failure |  | Hazard Ratio | |
---|---|---|---|---|---|
Variables | (N = 9) | (N = 71) | P value a | Ratio | 95% CI |
Mean age (years) | 61 [8] | 74 [9] | < 0.01 | 0.94 | 0.86-1.03 |
Male gender (percent) | 44 | 42 | 1.00 | 0.30 | 0.05-1.87 |
Mean body mass index (kg/m2) | 28 [7] | 27 [4] | 0.71 | - | - |
Obesity (body mass index ≥ 30 kg/m2) (percent) | 44 | 20 | 0.11 | 2.13 | 0.34-13.3 |
Diagnosis (percent) | Â | Â | Â | - | - |
   Osteoarthritis | 100 | 85 | 0.35 | - | - |
   Osteonecrosis | 0 | 15 |  | 0.00 | 0.00 |
Mean pre-op objective score (points) | 53 [10] | 49 [9] | 0.21 | 1.01 | 0.92-1.11 |
Mean pre-op functional score (points) | 51 [5] | 47 [10] | 0.30 | 1.07 | 0.96-1.19 |
Pre-op patellar osteophytes (percent of patients) | 33 | 46 | 0.38 | 0.27 | 0.07-2.01 |