Several surgical approaches including midvastus, subvastus, mini-parapatellar, quadriceps-sparring (QS) and parapatellar are currently used to perform total knee arthroplasty (TKA). Since none of published study exhibited a simultaneous comparison of all of them, a network meta-analysis has been conducted to compare the most widely used knee surgical approaches regarding the improvement of functional outcomes and the range of motion (ROM).
Randomised controlled trials (RCTs) comparing TKA approaches were searched in electronic databases, major orthopedics journals, and oral communications, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform until May 1st, 2020. Two reviewers independently selected trials and extracted data. The primary outcomes were functional scores at 6 months post-surgeryevaluated by KSS and WOMAC, and the ROM.
Sixty RCTs involving 5042 patients with 5107 TKA were included. No significant differences between different approaches were found for the KSS assessment or the WOMAC at 6 months. The mean of ROM at 6 months post-surgery were higher in the subvastus group than in all the others surgical approaches. The difference of ROM with subvastus approach was 7.3° (95% CI -14.1 to -0.1) with the midvastus approach, 11.1° (95% CI -18.7 to -2.8) with mini-parapatellar, 8.9° (95% CI -14.2 to -3.1) with standard parapatellar, and 9.2° (95% CI -16.1 to -1.8) with QS.
Network meta-analysis. Level 1.
No differences were found in functional outcomes over short or medium terms but subvastus seemed to increase the ROM at 6 months post-surgery. Until or unless future studies can demonstrate a long-term benefit, based on these results all studied surgical approaches to perform a TKA are equal.