Persistently High Hip Circumference after Bariatric Surgery Is a Major Hurdle to Successful Hip Replacement

The prevalence of class III obesity ( ？kg/m2) in black women is 18%. As class III obesity leads to hip joint deterioration, black women frequently present for orthopedic care. Weight loss associated with bariatric surgery should lead to enhanced success of hip replacements. However, we present a case of a black woman who underwent Roux-en-Y gastric bypass with the expectation that weight loss would make her a better surgical candidate for hip replacement. Her gastric bypass was successful as her BMI declined from 52.0？kg/m2 to 33.7？kg/m2. However, her hip circumference after weight loss remained persistently high. Therefore, at surgery the soft tissue tunnel geometry presented major challenges. Tunnel depth and immobility of the soft tissue interfered with retractor placement, tissue reflection, and surgical access to the acetabulum. Therefore a traditional cup placement could not be achieved. Instead, a hemiarthroplasty was performed. After surgery her pain and reliance on external support decreased. But her functional independence never improved. This case demonstrates that a lower BMI after bariatric surgery may improve the metabolic profile and decrease anesthesia risk, but the success of total hip arthroplasties remains problematic if fat mass in the operative field (i.e., high hip circumference) remains high. 1. Introduction According to NHANES 2009-2010, the prevalence of class III obesity (BMI ≥ 40？kg/m2) in black, white, Hispanic, and Mexican American women is 18.0%, 7.3%, 6.1%, and 6.7%, respectively [1]. For men, the prevalence also varies by ethnicity but is lower than 8% in all groups [1]. Due to their high rate of obesity, black women are highly likely to come to the attention of orthopedic surgeons after bariatric surgery for hip replacement. Bariatric surgery is associated with many benefits including the eradication or improvement of hyperglycemia, hypertension, dyslipidemia, hepatic steatosis, and obstructive sleep apnea [2]. All of these metabolic changes lead to decreased risk of anesthesia and postsurgical metabolic complications. But in our urban orthopedic clinic, we are observing persistently high hip circumferences in black women, even after major weight loss (MMM). Therefore we frequently encounter an unpublished and unexpected orthopedic risk: inadequate loss of subcutaneous fat in the operative field. To demonstrate the challenges, a representative case is presented. 2. Case With the expectation that her back and hip pain would resolve, a 51-year-old black woman, with a BMI of 52.0？kg/m2, underwent laparoscopic Roux-en-Y