title: Predicting total knee replacement pain: a prospective, observational study.
abstract: To describe the natural history of pain after total knee arthroplasty and to identify factors predicting excessive postoperative pain, we used a prospective, observational study assessing clinical and radiographic variables preoperatively and at 1, 3, 6, and 12 months after knee replacement. Data sources included the visual analog pain scale and other measures of patient health, psychologic state, and component reliability. Regression analyses were conducted to identify specific factors predictive of postoperative pain, controlling for inequality of variables, and confirmed using regression diagnostics. For 116 patients (149 knees; mean age, 66 years; 55.2% women), significant pain was reported by 72.3%, 44.4%, 22.6%, 18.4%, and 13.1%, respectively. No intergroup differences existed for anesthesia, weight, age, or gender. Patients with greater preoperative pain had more postoperative pain, used more home therapy, and postoperative manipulations. Preoperative depression and anxiety were associated with heightened pain at 1 year. Pain after knee replacement resolves quickly, declining to approximately (1/2) by 3 months. However, one in eight patients report moderate to severe pain 1 year after surgery despite an absence of clinical or radiographic abnormalities. Development of office-based preoperative screening tools and interventions for these patients may reduce postoperative costs and improve patient-perceived outcomes.
authors.affiliation: Northwestern University, Orthopedic Institute, Memorial Hospital Joint Reconstruction and Implant Service, and Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Chicago, IL 60611, USA. VictoriaBrander@aol.com
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Brander
authors.forename: S David
authors.initials: SD
authors.lastname: Stulberg
authors.forename: Angela D
authors.initials: AD
authors.lastname: Adams
authors.forename: R Norman
authors.initials: RN
authors.lastname: Harden
authors.forename: Stephen
authors.initials: S
authors.lastname: Bruehl
authors.forename: Steven P
authors.initials: SP
authors.lastname: Stanos
authors.forename: Timothy
authors.initials: T
authors.lastname: Houle
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000150:complications; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003863:Depression / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000453:epidemiology* / Q000523:psychology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors