The Chitranjan Ranawat Award: functional outcome after total knee replacement varies with patient attributes

UMMS Affiliation

Department of Orthopedics and Physical Rehabilitation; Clinical and Population Health Research Program; Department of Medicine, Division of Preventive and Behavioral Medicine

Publication Date


Document Type



Aged; Aged, 80 and over; Arthralgia; Arthroplasty, Replacement, Knee; Awards and Prizes; Body Mass Index; Disability Evaluation; Female; Follow-Up Studies; Humans; Male; Orthopedics; Osteoarthritis, Knee; Pain Measurement; Range of Motion, Articular; Retrospective Studies; Societies, Medical; Time Factors; Treatment Outcome; Walking


Orthopedics | Rehabilitation and Therapy


Total knee replacement effectively relieves arthritis pain but improvement in physical function varies. A clearer understanding of the patient attributes associated with differing levels of functional gain after TKR is critical to surgical decision making. We reviewed 8050 primary, unilateral TKR patients enrolled in a prospective registry between 2000 and 2005 who had complete data. We evaluated associations between 12-month function (SF12/PCS) and preoperative gender, age, BMI, emotional health (MCS), knee diagnosis, quadriceps strength, and physical function (PCS). More than 98% of patients reported pain relief (KS pain score). At 12 months, mean PCS gain was 13.6 points, but the distribution was bimodal. The mean gain in PCS in the 63% of patients with greater improvement was 21 (SD = 7), and 4.1 (SD = 7) in the remaining 37%. Increased likelihood of poor functional gain was associated with older age, body mass index (BMI) over 40, lower MCS, and poor quadriceps strength. While two-thirds of patients reported functional gain well above national average at 12 months post-TKR, 37% reported limited functional improvement. Further understanding of the patient attributes associated with limited improvement will guide the design of innovative strategies to improve functional outcomes. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

DOI of Published Version



Clin Orthop Relat Res. 2008 Nov;466(11):2597-604. Link to article on publisher's site

Journal/Book/Conference Title

Clinical orthopaedics and related research

Related Resources

Link to Article in PubMed

PubMed ID