A meta-analysis of the sub-vastus approach and medial parapatellar approach in total knee arthroplasty

Purpose

Both sub-vastus (SV) approach and standard medial parapatellar (MP) approach are performed in primary total knee arthroplasty (TKA). Proponents of SV approach stress its importance in decreasing lateral release and preserving function of the extensor mechanism with earlier rehabilitation. The purpose of this study was to summarize the best evidence to compare functional outcomes between SV approach and MP approach in TKA.

Methods

All relevant randomized controlled trials and quasi-randomized controlled trails comparing SV approach and MP approach in primary TKA were included, and the search strategy followed the requirements of the Cochrane Library Handbook. Methodological quality was assessed, and data were extracted independently by two authors.

Results

Ten studies involving 976 knees, which compared the clinical outcomes after TKA by SV approach and MP approach, were included. The results showed that the SV approach needed less lateral release (RR, 0.37; 95 % CI, 0.17–0.81; P = 0.01) and offered earlier straight leg raise (95 % CI, −3.11 to −0.69; P < 0.01) and superior knee flexion within 1 week postoperation (95 % CI, 1.96–8.20; P < 0.01) with no increase in the duration of surgery.

Conclusions

The preliminary results can be concluded that SV approach may provide an alternative to the MP approach with earlier rehabilitation and decreased lateral release rates in primary TKA; however, more high-quality randomized controlled trials should be designed to assess the medium and long-term outcomes between these two approaches.

Level of evidence

II.