Table 3.
Univariate analysis of surgical variables
| Parameter | Cases (N = 60) | Control subjects (N = 60) | Odds ratio (95% confidence interval) | p Value |
|---|---|---|---|---|
| Number of previous surgeries | ||||
| None (0) | 22 (37%) | 42 (70%) | 1.0 (referent) | |
| 1 | 21 (35%) | 13 (22%) | 3.1 (1.3, 7.3) | 0.0111 |
| > 1 | 17 (28%) | 5 (8%) | 6.5 (2.1, 19.9) | 0.0005 |
| Tibial component size | ||||
| < 3 | 18 (30%) | 14 (23%) | 1.5 (0.6, 3.4) | 0.5185 |
| 3 to 4 | 31 (52%) | 35 (58%) | 1.0 (referent) | |
| > 4 | 11 (18%) | 11 (18%) | 1.1 (0.4, 3.0) | 0.9999 |
| Femoral component size | ||||
| < 3 | 14 (23%) | 6 (10%) | 2.8 (1.0, 8.1) | 0.0777 |
| 3 to 4 | 35 (58%) | 42 (70%) | 1.0 (referent) | |
| > 4 | 11 (18%) | 12 (20%) | 1.1 (0.4, 2.8) | 1.0 |
| Polyethylene thickness (mm) | ||||
| < 12.5 | 28 (47%) | 28 (47%) | 1.0 (referent) | |
| 12.5 | 20 (33%) | 27 (45%) | 0.7 (0.3, 1.6) | 0.5525 |
| > 12.5 | 12 (20%) | 4 (7%) | 3. (0.9, 10.4) | 0.0930 |
| Patellar component size (mm) | ||||
| 32 | 14 (23%) | 4 (7%) | 5.44 (1.5, 19.1) | 0.0111 |
| 35 | 24 (40%) | 19 (32%) | 1.96 (0.8, 4.6) | 0.1395 |
| 38 | 18 (30%) | 28 (47%) | 1.0 (referent) | |
| 41 | 4 (7%) | 9 (15%) | 0.69 (0.2, 2.6) | 0.7488 |
| Patella component shape | ||||
| Oval | 52 (87%) | 57 (95%) | 1.0 (referent) | |
| Round | 8 (13%) | 3 (5%) | 2.92 (0.7, 11.6) | 0.2043 |
| Lateral release | ||||
| No | 50 (83%) | 55 (92%) | 1.0 (referent) | |
| Yes | 10 (17%) | 5 (8%) | 2.2 (0.7–6.9) | 0.2693 |
| Bearing type | ||||
| Fixed | 9 (15%) | 6 (10%) | 1.0 (referent) | |
| Mobile | 51 (85%) | 54 (90%) | 0.63 (0.2–1.9) | 0.4076 |