Characteristics of Clinical Practice Research Datalink-recorded cases of total knee replacement and matched controls
| Cases | Controls | P value | |
| Total (n) | 49 723 | 104 353 | – |
| Body mass index (SD) | 28.68 (4.93) | 25.83 (4.58) | P<0.001 |
| Prior diagnosis of ACL injury | 153 (0.31%) | 41 (0.04%) | P<0.001 |
| Prior diagnosis of meniscal injury | 4217 (8.48%) | 669 (0.64) | P<0.001 |
| Prior fracture around the knee | 11 328 (22.78%) | 17 779 (17.04%) | P<0.001 |