Sunnybrook Magazine - Spring 2016

New knee, old pain


Neuropathic pain is one of the reasons patients continue to experience pain after total knee replacement. This chronic pain is similar in sensation to burning or electric shock and may be caused by something minor such as light touch.

“Our study found that about 14 per cent of patients experience this pain five years after knee replacement,” says Helen Razmjou, lead investigator and advanced practice physiotherapist at Sunnybrook. “Considering the large number of joint replacement surgeries performed in Canada, a substantial number of people may be suffering from ongoing severe symptoms.”

The study, published in 2015 in the journal Physiotherapy Canada, looked at whether reporting neuropathic pain an average of five years after total knee replacement was related to indicators such as age, sex and disability before surgery. The team looked at data for 64 patients, and findings determined that the pain was no more or less common in men or women, the old or the young. “There was no demographic that was more predisposed to development of neuropathic pain than another,” says Razmjou.

Patients who are at a high risk for neuropathic pain are identifiable as early as one year after their operation and could benefit from preventive strategies. Physicians should inquire about the types of pain experienced by their patients. Certain surveys help to determine if neuropathic pain is at the root of the problem, as there is potential for medications that will ease it.