Blood loss closely correlates with body mass index in total hip arthroplasty performed through direct lateral approach

OBJECTIVE: To investigate total blood loss (TBL), intraoperative blood loss (IBL), post-operative drainage (POD), and other related variables in total hip arthroplasty (THA) performed through direct lateral approach.

METHODS: This study was completed in Shanghai Sixth People's Hospital, Shanghai, China, between January and December 2010. We analyzed 113 patients treated by THA through direct lateral approach. Recordable blood loss (RBL) was measured and TBL was calculated according to the Gross formula. Ordinal logistic regression analysis was used for TBL, IBL, and POD, with gender, age, body mass index (BMI), disease duration, and operative time as independent variables.

RESULTS: The average operative time was 51.5 +/- 10.4 (range: 35-70) minutes, with an average RBL of 454 +/- 144 (range: 150-180) ml. Average TBL was significantly higher (975 +/- 355, range: 430-2020 ml; p<0.001). In the analysis of variables, BMI closely correlated with TBL, IBL, and POD, with odds ratios of 4.80 (95% CI: 2.63-8.78 [TBL]), 5.39 (95% CI: 2.84-10.25 [IBL]), and 4.37 (95% CI: 2.43-7.89 [POD]). Moreover, TBL (54.172), IBL (55.198), and POD (39.139) correlated with trend test BMI.

CONCLUSION: The TBL, IBL, and POD closely correlate with BMI in patients undergoing THA through direct lateral approach.