Short- and mid-term clinical results of ultrasound-guided genicular nerve block in arthroplasty-related chronic postsurgical pain

Abstract

One-third of patients experience knee arthroplasty-related chronic postsurgical pain (CPSP), and CPSP negatively affects all dimensions of quality of life. We aimed to evaluate the short- and mid-term clinical results and success of ultrasound-guided genicular nerve block in patients with knee arthroplasty-related CPSP. The secondary outcome aimed to evaluate the relationship between clinical success and the presence of neuropathic pain. This study is a retrospective chart review of patients with knee arthroplasty-related CPSP who were referred to a pain clinic and were unresponsive to conservative treatments. We obtained the clinical evaluations of the patients at one, three, and six months before and after the procedure from patient records. We evaluated pain intensity with a 10-point numerical rating scale (NRS), the effects of knee pain on function with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scoring system, and the presence of neuropathic pain with the Douleur Neuropathic Pain 4 Questions. We accepted the clinical success of the procedure as a 50% or more reduction in pain intensity. We evaluated a total of 21 patients. The therapy was successful in 13 (61.9%), 12 (57.1%), and 7 (33.3%) patients at the first, third, and sixth-month visits, respectively. There was a statistically significant difference between the NRS and WOMAC scores. At baseline, neuropathic pain was present in 61.9% (n = 13) of the patients, and its presence was not related to clinical success at the first, third, and sixth- month visits. Ultrasound-guided genicular nerve block relieves pain and improves short- and mid-term functionality for patients with knee arthroplasty-related CPSP. The study resulted in clinical success in two-thirds of the patients in the early period and one-third in the sixth month.