Comparable outcomes in mini-midvastus versus mini-medial parapatellar approach in total knee arthroplasty: a meta-analysis and systematic review

Background Minimally invasive surgery (MIS) techniques in total knee arthroplasties (TKA) have gained popularity over conventional techniques due to benefits of hastened recovery and reduced complications. There are a variety of MIS techniques available and two most common techniques currently employed are the mini-midvastus (mMV) and mini-medial parapatellar (mMPP) approaches. This meta-analysis aims to compare the clinical outcomes and peri-operative parameters between mMV and mMPP in TKA in order to determine the presence of a superior technique. Methods A multi-database search was performed according to PRISMA guidelines. Data from studies comparing clinical outcomes and peri-operative parameters between mMV and mMPP approaches in TKA were extracted and analysed. Results A total of five randomized controlled trials were included for analysis, consisting of 190 mMV and 189 mMPP knees. Clinically unimportant differences were noted in blood loss and surgical time between the groups (5 mL less blood loss and 7 min less surgical time in mMV, P < 0.001). There was no statistically significant difference between both groups for Knee Society Score at 1 and 2 years, range of motion at 1 and 2 years, incision length or incidence of lateral retinacular release (all non-significant, P > 0.05). Conclusion The mMV and mMPP MIS TKA approaches have equivalent clinical outcomes. Despite a statistically significant longer operative time and higher mean blood loss in mMV than mMPP approach, clinically significant difference was not demonstrated. Both mMV and mMPP MIS techniques are reliable and safe to perform in TKA.