Table 3. Simple and Multiple Logistic Regression Analysis of Risk Factors for Periprosthetic Occult Femoral Fractures.
| Variable | Coefficient | SE | Wald statistic | Odds ratio | 95% CI | P-value | |
|---|---|---|---|---|---|---|---|
| Simple logistic regression | |||||||
| Age | -0.01 | 0.02 | -0.31 | 0.99 | 0.94-1.04 | 0.75 | |
| Male | -1.15 | 0.48 | -2.39 | 0.32 | 0.12-0.81 | 0.02* | |
| Female | |||||||
| BMI | 0.15 | 0.07 | 2.13 | 1.12 | 1.01-1.33 | 0.03* | |
| ONFH | 1 | ||||||
| Dysplastic hip | 1.09 | 0.55 | 1.96 | 2.97 | 1.00-8.82 | 0.07 | |
| Osteoarthritis | -0.58 | 1.07 | -0.55 | 0.56 | 0.07-4.55 | 0.59 | |
| PTOA | 0.11 | 1.10 | 0.10 | 1.12 | 0.13-9.63 | 0.92 | |
| Neck fracture | -16.38 | 2465.33 | -0.01 | NA | NA | 0.99 | |
| Fixation failure | -16.38 | 2917.01 | -0.01 | NA | NA | 0.99 | |
| Inflammatory arthritis | -16.38 | 3765.85 | -0.01 | NA | NA | 0.99 | |
| LCP sequelae | -16.38 | 3765.85 | -0.01 | NA | NA | 0.99 | |
| Dorr ratio | -5.09 | 2.90 | -1.75 | 0.01 | NA | 0.08 | |
| Dorr type A | 1 | ||||||
| Dorr type B | -0.30 | 0.48 | -0.62 | 0.74 | 0.29-1.89 | 0.53 | |
| Dorr type C | -0.43 | 1.09 | -0.39 | 0.65 | 0.08-5.56 | 0.70 | |
| CTI | -1.00 | 3.55 | -0.28 | 0.37 | 0.00-383.61 | 0.78 | |
| Corail® stem | 1 | ||||||
| Tri-lock® stem | -0.08 | 0.47 | -0.18 | 0.92 | 0.36-2.33 | 0.86 | |
| Stem length | -0.02 | 0.12 | -0.17 | 0.98 | 0.77-1.24 | 0.86 | |
| Multiple logistic regression | |||||||
| Male | -0.96 | 0.50 | -1.93 | 0.38 | 0.15-1.01 | 0.04* | |
| BMI | 0.12 | 0.07 | 1.67 | 1.13 | 0.98-1.30 | 0.10 | |
SE: standard error, CI: confidence interval, BMI: body mass index, ONFH: osteonecrosis of the femoral head, PTOA: post-traumatic osteoarthritis, NA: not available, LCP: Legg-Calvé-Perthes, CTI: cortical thickness index.
*P<0.05.