This study investigates the difference in quantitative sensory testing results and self-reported neuropathic pain in patients after Total Knee Arthroplasty surgery with and without persistent pain. The results demonstrate that patients with persistent post-operative pain demonstrate widespread mechanical, cold and heat hyperalgesia and also higher level of neuropathic-like pain.
Total Knee Arthroplasty causes pain relief and improves the functionality, however up to 15% of the patients suffer from persistent post-operative pain after the surgery. The aim of this study was to determine if such persistent pain is associated with neuropathic-like pain and QST impairments.
To answer the above questions 53 patients after TKA surgery were recruited, some with moderate to severe pain and some without pain. Patients completed self-report questionnaires and went through QST, including pressure pain threshold, cold and heat pain threshold and cold and warm detection threshold tests on the operated knee and on distant elbow.
The results demonstrated that there was an association between moderate to severe pain reported after the surgery and widespread mechanical and cold and heat hyperalgesia. Patients with persistent pain also demonstrated higher levels of neuropathic-type pain and less improvement after the surgery. The results suggest that some patients after TKA surgery continue to suffer from knee pain and dysfunction and raises a need for larger study assessing these patient pre and postoperatively.