Functional gain and pain relief after total joint replacement according to obesity status

Obesity becomes the big obstacle in the field of arthroplasty and demands total knee replacement (TKR) for proper knee functioning. The study emphasis on postoperative effects of obesity on knees functionality and pain, which comes out nil as improvements rate increased after surgery among obese people. 

Obesity is known to be linked with more pain and lower function before and following the total hip or knee replacement (THR or TKR). The study comprised a large representative U.S. cohort to evaluate the association of obesity and TKR or THR by determining the changes between pre- and post-operative pain and function. 

A total of 2,964 and 2,040 patients who had undergone TKR and THR, respectively between May 2011 and March 2013 analyzed to collect the pre- and postoperative data on joint pain, BMI and function. The HOOS/KOOS (Hip disability and Osteoarthritis Outcome Score/Knee injury and Osteoarthritis Outcome Score) and Short Form-36 Physical Component Summary [PCS] score were used to measure the pain and function, respectively. The BMI status determined as under or of healthy weight, obese, overweight, critically obese, or morbidly obese.

The THR and TKR treat patients known to have 14%and 25% severely or morbidly obese. Both groups exhibited a higher obesity level that showed a significant correlation with a lower PCS score at baseline and six months after treatment. The Severely and morbidly obese patients of THR group presented less postoperative PCS score than other BMI levels, whereas the TKR obese patients exhibited no significant postoperative gain in PCS and did not change by BMI level. Furthermore, In the THR group more pain at baseline but higher postoperative pain relief was correlated with greater obesity level, and therefore the mean postoperative pain scores showed no significant difference as per BMI status. In the THR group, greater obesity level was correlated with worse pain at baseline but more significant pain relief at 6 months, so the mean pain scores at 6 months were comparable across the BMI levels.

Severely or morbidly obese patients described remarkable pain relief and visible functional gain that was comparable to the findings in other patients after the six months after total joint replacement (TJR). While obesity is correlated with a higher risk of early complexities, obesity in itself should not be a deterrent to going through TJR to alleviate symptoms.