Table 5.
Results of multivariate analysis of cup failure
| Failures/I Implants | Unadjusted (95% CI) | Adjusted for all variables (95% CI) | P | |
| Gender | ||||
| Female | 82/2951 | 1 (referent) | 1(referent) | |
| Male | 52/1799 | 1.12 (0.79–1.58) | 0.76 (0.53–1.10) | p = 0.16 |
| Side | ||||
| Left | 60/2204 | 1 (referent) | 1 (referent) | |
| Right | 74/2546 | 1.08 (0.77–1.52) | 1.16(0.82–1.63) | p = 0.34 |
| Age at surgery | P --trend=0.005 | |||
| Between 40 and 69 | 86/2965 | 1 (referent) | 1 (referent) | |
| Higher than 70 | 27/1377 | 0.75 (0.49–1.16) | 0.66 (0.41–1.08) | p = 0.098 |
| Lower than 40 | 21/408 | 1.99 (1.24–3.21) | 2.02 (1.21–3.38) | p = 0.007 |
| Charnley's hip score | ||||
| Class A | 78/3027 | 1 (referent) | 1(referent) | |
| Class B+C | 56/1723 | 1.12 (0.79–1.57) | 1.15 (0.81–1.63) | p = 0.42 |
| Skills of surgeon | ||||
| More than 400 operations | 63/2604 | 1 (referent) | 1 (referent) | |
| Less than 400 operations | 71/2146 | 1.46 (1.04–2.05) | 1.23 (0.85–1.77) | p = 0.27 |
| Type of cup | P --trend=0.004 | |||
| Press fit, ceramic or metal liner | 50/2249 | 1 (referent) | 1 (referent) | |
| Cemented all polyethylene | 23/563 | 1.84 (1.12–3.01) | 2.68 (1.48–4.83) | p = 0.001 |
| Press fit, polyethylene liner | 61/1938 | 1.42 (0.98–2.06) | 1.53 (1.02–2.29) | p = 0.04 |
| Diagnosis in primary arthroplasty | P --trend=0.0001 | |||
| Primary arthritis | 51/2667 | 1 (referent) | 1 (referent) | |
| Sequelae of congenital and pediatric diseases | 44/865 | 2.44 (1.63–3.65) | 2.32 (1.49–3.62) | p = 0.0001 |
| Femoral neck fracture and sequelae | 29/681 | 2.41 (1.53–3.80) | 1.98 (1.24–3.17) | p = 0.004 |
| Other | 10/537 | 0.99 (0.50–1.95) | 0.46 (0.38–1.55) | p = 0.46 |