Effect of medial parapatellar versus modified V-Y quadricepsplasty approach on knee function and quadriceps strength in revision knee arthroplasty

PURPOSE: This study aimed to compare the clinical and functional outcomes of modified V-Y quadricepsplasty with those of medial parapatellar (MP) arthrotomy in the context of revision total knee arthroplasty (rTKA). It is hypothesized that there is no significant difference in clinical, radiological, and strength outcomes between V-Y quadricepsplasty and the medial parapatellar approach. MATERIALS AND METHODS: A retrospective comparative cohort study was conducted on 31 patients (19 who underwent an MP arthrotomy and 12 who underwent a modified V-Y quadricepsplasty) who had undergone rTKA. The clinical outcomes included knee range of motion (ROM), muscle strength, and functional scores (HSS, LEFS, WOMAC). Radiographic evaluations were conducted to assess mechanical axis deviation (MAD) and patellar height. RESULTS: Both groups were comparable in demographics. Clinical outcomes, including active ROM (89.5° ± 22.2° vs. 89.4° ± 8.9°; p = 0.985), extension deficit (0.41° ± 1.44° vs. 4.7° ± 7.5°; p = 0.061), flexion (93.7° ± 24.4° vs. 106.3° ± 16.7°; p = 0.099), and functional scores (HSS: 82.6 ± 12.1 vs. 85.8 ± 9.2, p = 0.408; LEFS: 43.4 ± 11.8 vs. 45.2 ± 12.2, p = 0.691; WOMAC: 24.3 ± 12.9 vs. 20.7 ± 17.3, p = 0.543) were similar between groups. Strength measurements showed no significant differences in peak extension (38.3 ± 16.8 Nm vs. 39.3 ± 12.9 Nm; p= 0.848) and peak flexion torque (22.6 ± 6.7 Nm vs. 24.8 ± 6.8 Nm; p = 0.392). Radiographic assessments showed no significant differences in MAD (15.4 ± 19.5 mm vs. 15.8 ± 13.6 mm; p = 0.951) and patellar height (1.1 ± 0.14 vs. 1.14 ± 0.25; p = 0.669). No complications were observed. CONCLUSIONS: Modified V-Y quadricepsplasty offers outcomes comparable to MP arthrotomy in rTKA, with the advantage of extended exposure for complex cases without compromising recovery. However, given the limited sample size and the exploratory nature of this study, these findings should not be interpreted as evidence of equivalence between the two approaches. LEVEL OF EVIDENCE: Level IV, Retrospective cohort.