APPROACHES TO THE KNEE IN ARTHROPLASTY SURGERY: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMISED CONTROLLED TRIALS

Abstract

Objectives: To compare the results of various surgical approaches to the knee in primary total knee arthroplasty (TKA) surgery.

Design: Systematic review with meta-analysis.

Data Sources: Cochrane Bone, Joint, and Muscle Trauma group trials register (2007), Cochrane central register of controlled trials (Cochrane Library issue 2, 2007), Medline (1950–2007), Embase (1974–2007), CINAHL (1982–2007), Pubmed, SCOPUS and ZETOC.

Review Methods: Randomised and quasi-randomised controlled trials comparing surgical approaches in patients undergoing primary TKA. Relative risks and 95% CIs were calculated for dichotomous outcomes, and weighted mean differences and 95% CIs calculated for continuous outcomes. Individually randomised trials were pooled whenever possible with the use of the fixed-effects model of Mantel-Haenszel.

Results: 53 articles were identified using our search strategy; of these, 32 were excluded from the systematic review. 21 trials involving 1082 patients (1170 TKAs) were included.

1. Midvastus (MV) vs Medial Parapatellar (MPP) approach:

   Quadriceps function in the early post operative period was better preserved in the MV group. Post operative pain, blood loss and the need for LRR tended to be lower in the MV group.

2. Subvastus (SV) vs Medial Parapatellar approach:

   Quadriceps function was better preserved in the SV group up to 3 months post operatively. ROM was generally greater up until the 4 week time point. Post operative pain and blood loss was lower in the SV group.

3. Midvastus vs Subvastus approach:

   The SV group suffered with significantly more pain at six months post operatively.

4. Quadriceps-sparing versus Medial Parapatellar Approach:

   Significantly longer operative times and more complications were noted in the QS group.

5. Modified ‘Quadriceps sparing’ Medial Parapatellar vs Mini-Subvastus (MSV) approach:

   A tendency for earlier restoration of SLR and better early ROM was noted in the MSV group.

Conclusions: Approaches preserving the quadriceps tendon improve the early extensor mechanism function and tend to decrease the need for LRR. Combined with a decrease in blood loss and postoperative pain, these approaches improve early rehabilitation and allow for a more rapid recovery of knee function. However, these early improvements fail to provide any long term benefit, do not improve knee scores, or decrease the length of hospital stay.

MIS tends to result in an improved early quadriceps function and decreased blood loss. However, these approaches are technically more demanding, result in longer operative times and provide no long-term benefit. There is concern that they result in a greater number of major complications and risk implant mal-alignment. Eversion of the patella seems to correlate with poor quadriceps function.