ACL and meniscal injuries increase the risk of primary total knee replacement for osteoarthritis: a matched case–control study using the Clinical Practice Research Datalink (CPRD)

ObjectivesThe aim of this study was to investigate whether ACL injury (ACLi) or meniscal injury increases the risk of end-stage osteoarthritis (OA) resulting in total knee replacement (TKR).MethodsA matched case–control study of all TKRs performed in the UK between January 1990 and July 2011 and recorded in the Clinical Practice Research Datalink (CPRD) was undertaken. The CPRD contains longitudinal data on approximately 3.6 million patients. Two controls were selected for each case of TKR, matched on age, sex and general practitioner location as a proxy for socioeconomic status. Individuals with inflammatory arthritis were excluded. The odds of having TKR for individuals with a CPRD-recorded ACLi were compared with those without ACLi using conditional logistic regression, after adjustment for body mass index, previous knee fracture and meniscal injury. The adjusted odds of TKR in individuals with a recorded meniscal injury compared with those without were calculated.ResultsAfter exclusion of individuals with inflammatory arthritis, there were 49 723 in the case group and 104 353 controls. 153 (0.31%) cases had a history of ACLi compared with 41 (0.04%) controls. The adjusted OR of TKR after ACLi was 6.96 (95% CI 4.73 to 10.31). 4217 (8.48%) individuals in the TKR group had a recorded meniscal injury compared with 669 (0.64%) controls. The adjusted OR of TKR after meniscal injury was 15.24 (95% CI 13.88 to 16.69).ConclusionThis study demonstrates that ACLi is associated with a sevenfold increased odds of TKR resulting from OA. Meniscal injury is associated with a 15-fold increase odds of TKR for OA.