Postoperative leg position following total knee arthroplasty influences blood loss and range of motion: a meta-analysis of randomized controlled trials

Abstract

Aim: Postoperative leg position has been reported as an efficient and convenient technique to minimize blood loss and improve early recovery following total knee arthroplasty (TKA); however, no single study was large enough to definitively determine optimal leg position. Therefore, we performed a meta-analysis pooling the results from randomized controlled trials (RCTs) to evaluate the effect of postoperative leg position on blood loss and range of motion (ROM) in TKA.

Methods: Potential academic articles were identified from the Cochrane Library, Medline (1966-October 2015), PubMed (1966-October 2015), Embase (1980-October 2015), ScienceDirect (1985-October 2015) and other databases. Gray studies were identified from the references of included literature reports. The pooling of data was analyzed by RevMan 5.1.

Results: Ten RCTs were included in the meta-analysis. There were significant differences in the total blood loss (mean difference [MD] = -130.66, 95% CI: -198.74 to -62.57, P = 0.0002), hidden blood loss (MD = -73.27, 95% CI: -117.57 to -28.96, P = 0.001), blood transfusion requirement (risk difference [RD] = -0.10, 95% CI: -0.19 to -0.22, P = 0.02), postoperative hemoglobin level (MD = 0.73, 95% CI: 0.42 to 1.04, P < 0.00001) and range of motion (MD = 3.79, 95% CI: 1.43 to 6.14, P = 0.002) between the flexion group and extension group. No significant differences were found regarding length of hospital stay, deep vein thrombosis (DVT) and wound infection between the two groups.

Conclusions: This meta-analysis indicated that the postoperative flexion position of the leg in TKA was effective and safe, significantly decreasing total blood loss, hidden blood loss and blood transfusion requirement. In addition, the postoperative range of motion is significantly improved by the flexion position of the leg.

Keywords: Arthroplasty; Blood loss; Knee position; Meta-analysis; Range of motion.