Chronic pain following total hip arthroplasty: a nationwide questionnaire study. Acta Anaesthesiol Scand 2006; 50: 495–500 2 Fischer HB, Simanski CJ. A procedure-specific systematic review and consensus recommendations for analgesia after total hip replac

Background: Chronic post-operative pain is a well-recognized problem after various types of surgery, but little is known about chronic pain after orthopedic surgery. Severe pre-operative pain is the primary indication for total hip arthroplasty (THA). Therefore, we examined the prevalence of chronic pain after THA in relation to pre-operative pain and early post-operative pain. Methods: A questionnaire was sent to 1231 consecutive patients who had undergone THA 12—18 months previously, and whose operations had been reported to the Danish Hip Arthroplasty Registry. Results: The response rate was 93.6%. Two hundred and ninety-four patients (28.1%) had chronic ipsilateral hip pain at the time of completion of the questionnaire, and pain limited daily activ-ities to a moderate, severe or very severe degree in 12.1%. The chronic pain state was related to the recalled intensity of early post-operative pain [95 % confidence interval (CI), 20.4—33.4%] and pain complaints from other sites of the body (95 % CI, 20.7—32.1%), but not to the pre-operative intensity of pain. Conclusion: Chronic pain after THA seems to be a significant problem in at least 12.1 % of patients. Our results suggest that genetic and psychosocial factors are important for the develop-ment of chronic post-THA pain. Accepted for publication 14 November 2005 Key words: chronic pain; post-operative pain; risk factors; total hip arthroplasty (THA). # Acta Anaesthesiologica Scandinavica 50 (2006) THE incidence of post-surgical pain is high afterseveral operations, such as amputation, mastectomy, thoracotomy, sternotomy, gallbladder surgery and inguinal hernia repair (1, 2). Up to 60—80 % of amputees experience phantom pain after amputation (3), and breast surgery is followed by chronic pain in 20—50 % of patients (4). A similar high percentage of patients develop chronic pain after thoracotomy (5), sternotomy (6) and femoro-popliteal bypass surgery (7). Common operations, such as gallbladder surgery, inguinal hernia repair and Cesarean section, may also lead to chronic pain in approximately 12—30 % of patient