Acute and Chronic Effects of Early Progressive Resistance Training on Knee Pain and Knee Joint Effusion After Unicompartmental Knee Arthroplasty

Purpose: To investigate if progressive resistance training initiated one week after unicompartment knee arthroplasty affect knee pain and knee joint effusion. Methods: Data from a previous randomized control trail was analysed.Knee pain was measured using a visual analogue scale, and knee circumference was used as an indication of knee joint effusion. Comparisons were made between the early (session 1+2) and late (session 15+16) phase of the 8-week intervention (chronic) and between the pre and post levels of single training sessions (acute). Results: Chronic effects: A significant decrease in pre- (55% SD 44%; p=0.004) and post-training (47% SD 53%; p=0.002) pain was observed. Also, a significant decrease in pre- (4.1% SD 3.3%; p=0.0001) and post-training (2.9% SD 2.7%; p=0.0004) circumference was observed. Acute effects: A significant increase in pain was observed in session 5, while a significant increase in circumference was observed in session 6-8, 10 and 13-16. Conclusion: Progressive resistance training initiated in the early post-operative phase following unicompartment knee arthroplasty does not increase the pain level immediately after a training session, despite frequent increases in joint effusion. Furthermore, pre- and post levels of pain and joint effusion dropped significantly following the intervention period.