Bypass can alleviate knee pain in obese patients

Gastric bypass surgery could alleviate knee osteoarthritis (OA) in obese patients according to the results of a study (The Impact of Gastric Bypass Surgery Compared to Total Knee Arthroplasty on Knee Symptoms), presented at the 2014 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS).

The study involved two groups of patients: 20 of the participants (16 women and four men) had undergone gastric bypass surgery and 40 participants underwent total knee replacement for symptomatic knee osteoarthritis. The participants were on average 52 years old and had a mean pre-operative BMI 45.6.

Researchers said the participants were matched two-to-one by age, gender and BMI. The study assessed knee symptoms before surgery, six months after surgery and a year after surgery.

Bariatric surgery patients reported significant improvement in mean knee pain (6.95 vs. 2.30 points) and physical function (21.5 vs. 7.05) at one-year follow up. When compared to patients who underwent TKR, the %age improvement in mean pain scores was similar between the two groups at six months (49.9% versus 58.3%) and one year (62.7% vs. 68.2%). The bypass group experienced a significantly greater %age improvement in physical function at six months (66.3% vs. 46.7%), and a similar, though marginally non-significant difference at one year (68.4% vs. 51.5%).

Comparatively, bypass patients with self-reported OA had greater knee pain and worse function preoperatively when compared to those without OA, as well as a smaller percentage improvement in pain (63.5% vs. 74%) and function (66.4% versus 72.9%) at final follow up.

The study authors recommend that surgeons consider bariatric consultation for obese patients who have knee symptoms but lack advanced osteoarthritis or other conditions amendable to orthopaedic management.