CHANGE IN BMI AFTER MID-FOOT AND HIND-FOOT ARTHRODESIS: A RETROSPECTIVE REVIEW OF PROSPECTIVELY COLLECTED DATA

Abstract

Introduction: Obesity has become a major public health epidemic, with recent reports citing that 22% of English men and 24% of women are clinically obese. Painful foot and ankle joints are often pointed out as an impeding factor for lack of mobility and weight reduction. There is an assumption that weight loss will occur after their surgery due to increased mobility.

The current study aimed to evaluate the effect of surgery on post operative body mass index (BMI) in patients who underwent mid-foot or hind-foot arthrodesis.

Patients and Method: All patients who underwent mid-foot and hind-foot arthrodesis under the care of senior author from April 2005 to Nov. 2006 were identified from the operating theatre records. In total 33 procedures were done in 31 patients. Each patient’s BMI recorded pre-operatively was compared with that recorded at a minimum of 6 months postoperatively using the paired Student’s t-test. Analysis of the data was also conducted by stratifying pre-operative BMI, good pain relief (i.e AOFAS> 80), sex and fusion site.

Results: It was found that there was a mean increase of BMI by 0.25 (95% CI of −0.95 to 0.44) with p-value of 0.47.

It was noted that BMI of patients in obese group increased post-operatively by 0.07 (95% confidence interval of −1.52 to 1.66) with p-value of 0.9.

Discussion: This study highlights the fact that there is no significant effect on BMI in obese patients despite significant increase in mobility and pain levels after mid-foot and hind-foot arthrodesis. The change in BMI after fusion surgery is not significantly effected by sex nor quality of pain relief.