Body mass index as a predictor of outcome in total knee replace: A systemic review and meta-analysis.

BACKGROUND: To conduct a meta-analysis with randomized controlled trials (RCTs) published in full text to demonstrate database to show the associations of perioperative, postoperative outcomes of normal and high body mass index (BMI) to provide the predictive diagnosis for clinic.

METHODS: Literature search was performed in PubMed, Embase, Web of Science and Cochrane Library for information from the earliest date of data collection to February. RCTs comparing the benefits and risks of normal BMI with those of high BMI in primary total knee arthroplasty (TKA) were included. Statistical heterogeneity was quantitatively evaluated by X2 test with the significance set P<0.10 or I2 >50%.

RESULTS: Seven RCTs consisting of 33,778 patients were included. (6065 normal BMI patient; 27,713 high BMI). The results showed that high BMI was related to a greater increase in operative time, post-operative range of motion (ROM), post-operative Knee Society and function scores (KSS), infection rate (P<0.1). No differences in pulmonary embolism and perioperative mortality rates were found between normal and high body mass index patients with follow-up≥5years (P>0.1).

CONCLUSIONS: Compared with normal BMI patients, high BMI patients demonstrated an increased risk of perioperative and postoperative complications and clear difference about complications between normal and high BMI about TKA.