Quantitative analysis of patellar tendon after total knee arthroplasty using echo intensity. A non-randomized controlled trial of alpine skiing

Abstract Background Despite the knee extensor weakness, less attention has been paid to the evaluation of patellar tendon after total knee arthroplasty (TKA). We previously observed patellar tendon hypertrophy after TKA. The purpose of this study was to reanalysis these ultrasound data to detect whether brightness mode ultrasound imaging reflects pathological changes of the patellar tendon after TKA. Methods Twenty-eight participants with post unilateral TKA were assigned to an intervention group (IG) or control group (CG). The IG underwent a 12-weeks skiing program. Patellar tendon mechanical properties were obtained by combining isometric dynamometry, ultrasound imaging and electromyography in operated knee (OP) and non-operated knee (NOP). Luminosity ratio (LR) was measured using EI in a relaxed and maximally loaded phase. Results Baseline comparisons revealed significant effects of the surgical side (p Conclusion Patellar tendon LR is decreased along with degenerative change after TKA. Ultrasound imaging provides a promising metric to acquire in vivo patellar tendon pathological assessment after TKA.