| Background. The increasing number of primary total knee arthroplasties (TKA) may lead to higher rates of revision procedures, especially in the elderly. There is a paucity of literature, however, pertaining to the identification of risk factors for prosthetic failure. In particular, little is known regarding the effect of physical activity on the need for revision TKA. This matched case control study tested the hypothesis that individuals with higher physical activity levels after primary TKA would have a greater risk of needing revision TKA than individuals with lower physical activity levels.; Methods. The cases had at least one primary TKA due to osteoarthritis (OA) within the past two to 15 years, and revision TKA of at least the tibial or femoral component within the past five years. The controls had at least one primary TKA due to OA and no revision TKA. The cases and controls were matched on age, gender, number of knees replaced, and date of primary TKA. Historical leisure and occupational physical activity was assessed after primary TKA. Statistical analyses were conducted to identify the variables that predicted the need for revision TKA.; Results. Nine male and 17 female pairs, aged 47 to 85 (mean age 70.5 years), participated in the study for a total of 26 pairs. The controls consistently performed more leisure and occupational activity than the cases after primary TKA regardless of intensity level, impact level, or number of knees replaced. In general, the differences in physical activity between the cases and controls were greater in males than females. Physical activity was not associated with an elevated risk of revision TKA.; Conclusion. This was the first study to quantify and describe patterns of physical activity in an older population with TKA. Physical activity did not appear to be a risk factor for revision TKA in this study. There was some indication that physical activity may reduce the need for revision TKA but the results were not statistically significant. Our results would suggest that individuals undergoing primary TKA should be encouraged to remain active after surgery. |
