Compare the Quadriceps Activity between Mini-Midvastus and Mini-Medial Parapatellar Approach in Total Knee Arthroplasty with Electromyography.

Background: The comparison between the mini-midvastus (mini-MV) and mini-parapatellar (mini-MPP) approach in total knee arthroplasty (TKA) remains a subject of debate. The present study compared quadriceps activation, pain levels, and clinical outcomes between the two approaches; quadricep activation was assessed using surface electromyography (sEMG). Methods: This retrospective cross-sectional study comprised a total of 78 patients aged between 50 and 85 years with primary osteoarthritis. Patients were divided into a mini-MV (n = 38) group and a mini-MPP (n = 40) group according to the surgical approach. Results: The two groups exhibited no significant differences in sEMG for the vastus medialis (VM) or rectus femoris (RF) at the follow-up time points, with the exception that the mini-MV group exhibited superior strength of RF during extensions at the 2-week follow-up. However, the mini-MPP group had superior Western Ontario and McMaster Universities Index (WOMAC) total and function scores at the 2- and 6-week follow-ups. The mini-MPP group also had superior WOMAC stiffness scores at the 2-week follow-up. The two groups did not differ significantly in terms of pain levels or morphine consumption. Conclusions: The sEMG data of quadriceps muscle would not differ significantly between the mini-MV and mini-MPP approaches for TKA. Moreover, the mini-MPP approach may yield superior WOMAC scores when compared with the mini-MV approach.