Table 2.
Results of the comparison between UKAs without and with fractures
| No. of clinical studies | Group | No. of knees | Mean ± SD or % | P value§ | |
|---|---|---|---|---|---|
| Body mass index (kg/m2) | 4 | UKAs without fractures | 1379 | 26.3 ± 6.8* | 0.017 |
| UKAs with fractures | 12 | 31.0 ± 6.8 | |||
| Age (yrs) | 14 | UKAs without fractures | 2701 | 64.4 ± 9.2* | 0.003 |
| UKAs with fractures | 24 | 70.0 ± 9.2 | |||
| Bone mineral density (g/m2) | 1 | UKAs without fractures | 155 | 0.73 ± 0.10 | 0.030 |
| UKAs with fractures | 12 | 0.65 ± 0.16 | |||
| Tibial component angle (°) | 1 | UKAs without fractures | 155 | 4.19 ± 2.94 | 0.130 |
| UKAs with fractures | 12 | 2.83 ± 2.69 | |||
| Postoperative Tibia-femoral Angle (°) | 1 | UKAs without fractures | 155 | 176.5 ± 3.6 | 0.012 |
| UKAs with fractures | 12 | 179.3 ± 3.3 | |||
| Gender (Female/Male) | 20 | UKAs without fractures | 5910 | 67%/33% | 0.011 |
| UKAs with fractures | 58 | 83%/17% | |||
| Activity level (High/Low) # | 1 | UKAs without fractures | 566 | 20%/80% | 0.976 |
| UKAs with fractures | 10 | 20%/80% | |||
| Very overhanging medial tibial condyle (Yes/No) † | 1 | UKAs without fractures | 150 | 12%/88% | < 0.001 |
| UKAs with fractures | 6 | 67%/33% |
§Chi square test was used for categorical variables and the independent t test for continuous variables
#Patients with an UCLA (University of California Los Angeles) activity score > 6 were classified as high
*The weighted mean of the overall UKA population with the same standard deviation as the tibial plateau fracture cases was used to allow for a fair comparison. This means this is an estimation and not the exact mean with standard deviation of the UKAs without fractures
†Very overhanging medial tibial condyle was defined as a medial eminence line outside the medial cortex of the tibial shaft as described by Yoshikawa et al.[95]