Mini-midvastus versus medial parapatellar approach in TKA: muscle damage and inflammation markers

The purpose of this prospective study was to analyze the biochemical markers of muscle damage and inflammation in patients treated with the mini-midvastus approach or the medial parapatellar approach for total knee arthroplasty. Of 60 patients who underwent unilateral total knee arthroplasty, 30 were treated with the mini-midvastus approach (MMV group) and 30 were treated with the medial parapatellar approach (MPP group). Serum creatine kinase, myoglobin, lactate dehydrogenase, glutamic oxaloacetic transaminase, C-reactive protein, interleukin-6, and interleukin-1β levels were measured preoperatively, immediately postoperatively (except for C-reactive protein level), and on postoperative days 1, 2, and 3. Student's t test, Pearson's chi-square test, and Fisher's exact test were used to compare the outcomes between the 2 groups. Compared with the MPP group, a significant increase in serum creatine kinase level existed in the MMV group on postoperative days 2 (P=.08) and 3 (P=.09) and cumulatively (P=.02). However, significantly elevated C-reactive protein and interleukin-6 levels existed in the MPP group.According to the serum creatine kinase levels, the mini-midvastus approach has no superiority over the medial parapatellar approach in terms of sparing muscle and may cause more muscle damage. Further study is warranted to determine the correlation between biochemical markers and functional deficits.