LAS VEGAS, Nevada—The first studies of joint replacement in the very fat show “alarmingly high” complication rates in the super-obese (BMI>50) and suggest that weight loss or bariatric surgery should come first, according to research reported at the American Academy of Orthopaedic Surgeons (AAOS) 2009 meeting.^1,2 Although the slightly less obese (BMI>40) report pain relief and postoperative satisfaction similar to more slender patients, these results require lengthier operative procedures and should qualify for higher reimbursement rates, the surgeons say.^3,4

Joint replacement in obese feasible but risky

“As an orthopaedic surgeon practicing in a state where the obesity rate is 30% of its population, I have seen firsthand the challenges that arise when operating on obese patients,” said George Russell, MD, in a press briefing titled, “Obesity: A Musculoskeletal Nightmare.” Dr. Russell is an orthopaedic trauma surgeon at the University of Mississippi Medical Center. He said that the new findings will prepare obese patients for information on what to expect during the pre-operative and post-operative phases of joint replacement.

David J. Polga, MD, and colleagues from the Mayo Clinic in Rochester, Minnesota, studied complications following total hip arthroplasty or total knee arthroplasty in super-obese (BMI>50) patients.^1,2 [A typical “super-obese” patient might be a 5'8” subject who weighs 325-350 pounds.] The researchers found that both total hip and total knee replacements are feasible for super-obese patients, but both procedures are associated with “alarmingly” high complication rates

“Patients should be counseled regarding these risks and encouraged to lose weight or referred to a bariatric specialist preoperatively,” Dr. Polga said.

Hip arthroplasty was associated with surgical complications in nearly 40% of cases, medical complications in 17%, 5 deaths, and a minor complication rate of 25.6%. The major complication rate, requiring reoperations, was 12.2%. Similarly, knee arthroplasty in super-obese patients was associated with surgical complications in 40.6%, medical complications in 14.3% (including 2 deaths), minor complications in 22.6%, and major complications in 14.3% of cases.  

Cale Jacobs, PhD, and Christian P. Christensen, MD, from the Lexington Clinic in Lexington, Kentucky, found that morbidly obese patients (BMI >40) had pain relief and posterative satisfaction rates equal to those in non-obese subjects after total knee replacement.³

“Despite having significantly decreased range of motion and function scores, morbidly obese TKA patients did not differ in satisfaction with their surgery when compared to their non-obese counterparts,” Drs. Jacobs and Christensen reported.

However, these researchers also found that achieving these results required considerably more resources. “Despite being significantly younger [than non-obese patients], morbidly obese patients had significantly longer operative times and hospitals stays, and a significantly greater proportion of the morbidly obese patients required care at a rehabilitation or skilled nursing facility. Morbidly obese patients place greater demand on the surgeon, hospital, and health care system and generate correspondingly greater health care costs,” they concluded.⁴

References

1. Polga DJ, Altenburg A, Trousdale RT, et al. Hip Arthroplasty: Outcomes, Fixation, Operative Approaches Complications Following Total Hip Arthroplasty in the Superobese, BMI>50. Oral presentation at the American Academy of Orthopaedic Surgery 2009 meeting, Las Vegas, 26 February 2009, Presentation No: 256.
2. Polga DJ, Altenburg A, Trousdale RT, et al. Complications Following Total Knee Arthroplasty in the Superobese, BMI>50. Oral presentation at presentation at the American Academy of Orthopaedic Surgery 2009 meeting, Las Vegas, 26 February 2009, Presentation No: 280.
3. Jacobs C, Christensen CP.  Morbidly Obese TKA Patients Demonstrate Similar Pain Relief and Postoperative Satisfaction. Poster presentation at the American Academy of Orthopaedic Surgery 2009 meeting, Las Vegas, 26 February 2009, Presentation No: P156.
4. Jacobs C, Christensen CP.  Morbidly Obese TKA Patients Require Lengthier Operative Procedure and Hospital Stay. Poster presentation at the American Academy of Orthopaedic Surgery 2009 meeting, Las Vegas, 26 February 2009, Presentation No: P155.