Abstract
What are the data on obesity and THA risk? Which complications are elevated? If you decide on surgery, how can you minimise complications? These are timely questions because the rates of obesity are rising in the US and in many other parts of the world.
Does obesity increase risk of THA complications? Answer: yes: at least for some complications.
Complications which are increased: infection, wound healing, nerve injury; possibly: dislocation, periprosthetic fractures. The data are mixed on whether aseptic loosening and/or bearing surface wear problems are increased in the obese. Higher BMI may be offset by lower activity levels, particularly in a congruent joint such as the hip.
Outcomes of THA in obese: Lower function scores and activity scores compared to nonobese. But good pain relief and the preoperative to postoperative change in functional scores is similar to non-obese.
Is there a critical BMI threshold above which complications become unacceptable? Several studies show BMI ≥40 associated with strong risk of complications. One study from Mayo Clinic on patients with BMI ≥50 showed a 39% surgical complication rate, a 12% medical complication rate, and a high mortality rate in the several years after THA. Individualise operative decisions based on risk/benefit analysis for each patient.
If you decide to operate, how can you minimise risk? Lose weight before surgery by diet: often ineffective, but worth trying. Lose weight before THA with bariatric surgery: effective in producing weight loss, but beware of the “malnourished” obese patient
In surgery: care with patient positioning, sufficient incision length, greater exposure, avoid sciatic nerve injury, fractures, care with acetabular component positioning, extra drains in subcutaneous tissue and wound compression.
Engage patient in discussion of risks/benefits before surgery: shared decision making.
