Some people just don't do as well as others after a total hip replacement (THR). There is some thought that obesity puts patients at increased risk for problems after surgery. Doctors may even refuse to operate on patients who are overweight. This study reports that body mass index (BMI) is no reason to withhold THR.
Doctors at the Queen Margaret Hospital in England followed 800 patients for 18 months after having their first THR. They measured pain, range of motion, and activity.
They also looked at the number of dislocations, reoperations, and deaths. Problems such as blood loss, infection, and blood clots were factored in as well.
The researchers report no evidence that obesity is linked to problems after THR or failure of the implant. In fact the more obese patients were less active. Less activity means less load on the new joint.
The authors think it's more likely a group of factors puts patients at risk for failure after a THR. It may be that a two or three medical problems such as smoking, diabetes, and heart disease puts the patient at risk for problems. These conditions are linked with obesity.
More study is needed to sort out all the factors before patients are denied treatment. These patients will continue to be followed to assess medium-and long-term effects of body mass.
Matthew Moran, MRCSEd, et al. Does Body Mass Index Affect the Early Outcome of Primary Total Hip Arthroplasty? In The Journal of Arthroplasty. October 2005. Vol. 20. No. 7. Pp. 866-869.'