Table 6.
Results of multivariate analysis of stem failure
| Failures/Implants | Unadjusted | Adjusted for all variables (95% CI) | P | |
| Gender | ||||
| Female | 39/2951 | 1 (referent) | 1 (referent) | |
| Male | 47/1799 | 2.09 (1.37–3.19) | 2.00 (1.28–3.12) | p = 0.002 |
| Side | ||||
| Left | 38/2204 | 1 (referent) | 1 (referent) | |
| Right | 48/2546 | 1.10 (0.72–1.69) | 1.21 (0.78–1.85) | p = 0.39 |
| Age at surgery | P --trend=0.048 | |||
| Between 40 and 69 | 58/2965 | 1 (referent) | 1 (referent) | |
| Higher than 70 | 18/1377 | 0.73 (0.43–1.24) | 0.58 (0.33–1.00) | p = 0.18 |
| Lower than 40 | 10/408 | 1.37 (0.70–2.69) | 1.66 (0.81–3.44) | p = 0.02 |
| Charnley's hip score | P --trend= 0.120 | |||
| Class A | 45/3027 | 1 (referent) | 1 (referent) | |
| Class B+C | 41/1723 | 1.46 (0.95–2.22) | 1.56 (1.02–2.39) | p = 0.40 |
| Skills of surgeon | ||||
| More than 400 operations | 28/2604 | 1 (referent) | 1 (referent) | |
| Less than 400 operations | 58/2146 | 2.670 (1.70–4.19) | 1.99 (1.21–3.29) | p = 0.007 |
| Type of stem | P --trend= 0.001 | |||
| Straight cemented stem | 41/1476 | 1 (referent) | 1 (referent) | |
| Anatomic cemented or straight cemented with particular design | 14/423 | 1.59 (0.86–2.95) | 1.19 (0.63–2.26) | p = 0.59 |
| Straight cementless | 13/782 | 0.64 (0.34–1.19) | 0.45 (0.23–0.88) | p = 0.019 |
| Surface treated or anatomic cementless | 8/1101 | 0.24 (0.11–0.51) | 0.24 (0.11–0.52) | p = 0.0001 |
| Modular cementless | 10/968 | 0.45 (0.23–0.90) | 0.46 (0.22–0.98) | p = 0.045 |
| Diagnosis in primary arthroplasty | P --trend=0.001 | |||
| Primary arthritis | 43/2667 | 1 (referent) | 1 (referent) | |
| Sequelae of congenital and paediatric diseases | 12/865 | 0.80 (0.42–1.52) | 0.99 (0.50–1.99) | p = 0.99 |
| Femoral neck fracture and sequelae | 23/681 | 2.26 (1.36–3.75) | 1.84 (1.09–3.12) | p = 0.02 |
| Other | 8/537 | 0.94 (0.44–2.00) | 0.75 (0.34–1.65) | p = 0.48 |