The connection between patient pain and clinical orthopaedic outcomes has received much attention lately. Here are relevant findings from two recent studies:
–An in-press study of 48 patients (average age of 72 years) who underwent TKA found that those with low pain thresholds prior to surgery (as measured with VAS scores while a blood-pressure cuff was inflated over the proximal forearm) were more likely to have lower Knee Society pain and function scores two years after surgery than those with moderate or high pain thresholds. The authors use this test in preoperative workups, and they advise patients who grade the cuff stimulus as severe that “their clinical outcomes are expected to be inferior to [those of] other patients,” encouraging such patients to take that into account before consenting to surgery.
–Among more than 1,100 patients (average age of 67 years) who participated in the Multicenter Osteoarthritis Study (MOST), inflammation, as evidenced by synovitis and effusion, was associated with reduced pain thresholds. However, resolution of established inflammation did not deliver a significant change in pain thresholds over two years, leading the authors to conclude that “early targeting of inflammation is a reasonable strategy to test for prevention of sensitization and…reduction of pain severity.”