Minimally Invasive Intermuscular Approaches versus Conventional Approaches in Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

INTRODUCTION: To date, the literature has not yet revealed superiority of Minimally Invasive (MI) approaches over conventional techniques. We performed a systematic review to determine whether minimally invasive approaches are superior to conventional approaches in total hip arthroplasty for clinical and functional outcomes. We performed a meta-analysis of level 1 evidence to determine whether minimally invasive approaches are superior to conventional approaches for clinical outcomes.

METHODS: All studies comparing MI approaches to conventional approaches were eligible for analysis. The PRISMA guidelines were adhered to throughout this study. Registries were searched using the following MeSH terms: 'minimally invasive', 'muscle-sparing', 'THA', 'THR', 'hip arthroplasty' and 'hip replacement'. Locations searched included PubMed, the Cochrane Library, ClinicalTrials.gov, the EU clinical trials register and the International Clinical Trials Registry Platform (World Health Organisation).

RESULTS: Twenty studies were identified. There were 1,282 MI THAs and 1,351 conventional THAs performed. There was no difference between MI and conventional approaches for all clinical outcomes of relevance including all-cause revision (p=0.959), aseptic revision (p=0.894), instability (p=0.894), infection (p=0.669) and periprosthetic fracture (p=0.940). There was also no difference in functional outcome at early or intermediate follow-up between the two groups (p=0.38). In level I studies exclusively, random-effects meta-analysis demonstrated no difference in aseptic revision (p=0.461) and all other outcomes between both groups.

CONCLUSIONS: Intermuscular MI approaches are equivalent to conventional THA approaches when considering all-cause revision, aseptic revision, infection, dislocation, fracture rates and functional outcomes. Meta-analysis of level 1 evidence supports this claim.