Does Obesity Hinder Pain Relief Following Total Joint Replacement?

Obesity does not affect pain relief or function after total hip or knee replacement surgery, according to a recent study.

In the study, researchers evaluated preoperative and 6-month postoperative data on function and joint pain in relation to body mass index (BMI) using a national sample of 2040 patients who underwent total hip replacement surgery and 2964 patients who underwent total knee replacement surgery. Function was assessed using the Short Form-36 Physical Component Summary (PCS) score, joint pain was assessed using the Hip disability and Osteoarthritis Outcome Score and Knee injury and Osteoarthritis Outcome Score, and BMI status was defined as under or normal weight, overweight, obese, severely obese, and morbidly obese.
___________________________________________________________________________________________________________________________________________
RELATED CONTENT
Prior Microfracture Impairs Clinical Improvement After Knee Replacement Surgery
Dairy Intake Raises Risk for Hip Replacements in Some OA Patients
___________________________________________________________________________________________________________________________________________

Of the patients who underwent total hip replacement and total knee replacement, 14% and 25% were severely or morbidly obese, respectively.

A greater obesity level was associated with worse PCS scores at baseline and 6 months after surgery for patients who underwent either total hip or total knee replacement surgery.

While BMI was associated with postoperative functional gain for patients who underwent total hip replacement, BMI was not associated with postoperative gain in patients who underwent total knee replacement.

Patients with severe or morbid obesity who underwent either total hip or total knee replacement experienced more pain at baseline and experienced greater postoperative pain relief. The average pain scores at 6-month after surgery did not differ significantly across BMI levels.

“Six months after total joint replacement (TJR), severely or morbidly obese patients reported excellent pain relief and substantial functional gain that was similar to the findings in other patients,” the researchers concluded. “While obesity is associated with a greater risk of early complications, obesity in itself should not be a deterrent to undergoing TJR to relieve symptoms.”

—Melissa Weiss

Reference:

Li W, Ayers DC, Lewis CG, Bowen TR, Allison JJ, Franklin, PD. Functional gain and pain relief after total joint replacement according to obesity status [published online July 19, 2017]. J Bone Joint Surg Br. doi:10.2106/JBJS.16.00960.