The incidence of complex regional pain syndrome following total knee arthroplasty: a prospective multicentre observational study of 1,026 patients with no cases identified according to the Budapest criteria

Aim Our aim was to determine the incidence of complex regional pain syndrome (CRPS) according to the Budapest diagnostic criteria of the International Association for the Study of Pain (IASP) in patients following primary total knee replacement (TKR) surgery for osteoarthritis. Methods Patients undergoing primary TKR were recruited prospectively. At routine postoperative follow-up, all participants were assessed systematically for CRPS using the Budapest criteria. Results A total of 1,026 patients were recruited across three hospitals during a four-year period. Symptoms reported included: sensory 6% (n=61), vasomotor 7% (n=71), sudomotor 4% (n=41) and motor 1% (n=10). Signs observed included: sensory 7% (n=71), vasomotor 2% (n=20), sudomotor 3% (n=30) and motor 1% (n=10). No cases of CRPS according to the Budapest diagnostic criteria were identified. Conclusion CRPS appears to be an exceptionally rare diagnosis following primary TKR. We did not identify any cases in this prospectively designed adequately powered multicentre study.