Orthopedic joint surgeons are encountering a complex, growing problem with relatively young, morbidly obese patients who suffer from degenerative osteoarthritis. Obesity most commonly affects the knee joint, although the hip may be involved as well. Co-morbidities such as diabetes, hypertension and thyroid disease are commonly seen in this patient population.

Advanced disease often does not respond to conservative management, such as physical therapy, intra-articular injections and anti-inflammatories. The prolonged use of anti-inflammatory medication and steroid injections is not ideal, particularly in the young patient, especially with diabetes. Recent studies have shown that joint surgery may be successfully achieved with good pain relief and a return to a satisfactory functional level.

Weight loss is initially addressed, but most patients are unable to participate in a regular exercise program, due to joint pain and poor cardiovascular conditioning. Dieting may be helpful in the short term, but crash diets will lead to a poor nutritional status and a rapid weight gain once the diet is discontinued. Gastric bypass surgery may be a good option for some patients. However, side effects including redundant soft tissue, muscle atrophy and poor nutrition should be addressed prior to joint surgery.

Technical surgical challenges include manipulation and positioning of the extremity intraoperatively. Large extremities may restrict range of motion and standard instrumentation may fall short in terms of critical measurements and retraction of soft tissues. Surgeons who are experienced with joint surgery in this population should be sought out since there are modifications to the standard technique that may be helpful. It appears that morbidly obese patients may benefit from more constrained knee replacements since this may assist with reducing strain on adjacent ligaments. The incidence of infection may be increased, but this is generally associated with diabetes, venous stasis, and post operative seroma (fluid collection).

The morbidly obese patient who has X-ray evidence of advanced osteoarthritis that has failed non-operative measures may be considered for total joint replacement. The success rate is high when all precautions are taken to minimize perioperative complications. Some of the most successful outcomes we have seen at UAB are in the young, highly-motivated obese patients. It is not uncommon for these patients to participate in regular exercise programs following surgery and achieve the weight loss they want along with dramatic changes in their quality of lives.

Herrick J. Siegel, MD, is Associate Professor of Surgery, UAB School of Medicine