Introduction: Although the clinical and functional outcomes of patients undergoing knee arthroplasty have widely been investigated, there is little information on the postoperative sport activity status.
Sources of data: We performed a comprehensive search of CINAHL, Embase, Medline and the Cochrane Central Registry of Controlled Trials, from inception of the database to 25 February 2011, using various combinations of the keyword terms 'Knee arthroplasty', 'Knee replacement', 'Total Knee replacement', 'Unicondylar Knee replacement', 'Knee Prosthesis', 'Sport Activity', 'Return To Sport Activity Level' and 'Recreational Sporting Level'. Twenty-two articles published in peer-reviewed journals were included in this review.
Areas of agreement: Patients report improved outcomes, in terms of pain, symptoms, activities of daily living, sport activity and quality of life, compared with preoperative status. Only low-impact physical activities are recommended. The Coleman Methodology Score showed great heterogeneity in the study design, patients' characteristics, management methods and outcome assessment, and generally low methodological quality.
Areas of controversy: Data are too heterogeneous to allow for definitive conclusions on long-term outcomes of total knee arthroplasty. It is not possible to compare the post-operative sport activity status of the patients.
Growing points: Validated and standardized measures should be used to report outcomes of patients undergoing knee arthroplasty. Function surveys that better depict sport activities, and include actual physical function testing, should be used.
Research: There is a need to perform appropriately powered randomized clinical trials using standard diagnostic assessment, and a common and validated scoring system comparing reported outcomes and the duration of follow-up >2 years.