Oxford Knee Score
Also known as: OKS, Oxford Score Knee
The Oxford Knee Score (OKS) is a brief, validated self-report questionnaire developed by Murray and colleagues at the University of Oxford in 1998 to measure outcomes following knee replacement surgery. The OKS comprises 12 items assessing knee pain, knee-related functional limitations, and quality of life in patients undergoing total knee arthroplasty. It is the primary patient-reported outcome measure for knee replacement in international orthopedic research and clinical practice.
Key highlights
- Brief 12-item format (5 minutes) enabling routine administration in busy orthopedic clinics
- Extensively validated with excellent psychometric properties across diverse knee replacement populations
- Patient-centered focus captures meaningful outcomes rather than only technical surgical success
- Strong responsiveness to knee replacement demonstrating clinically significant improvements
Intuition
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How it works
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When to use it
OKS is indicated for measuring outcomes in patients undergoing knee replacement surgery for osteoarthritis or other knee pathology. Use preoperatively to establish baseline knee function and postoperatively (typically 3-6 months and 1 year) to assess functional recovery. Appropriate for orthopedic surgery outcome monitoring and comparative effectiveness research.
Strengths & limitations
- Brief 12-item format (5 minutes) enabling routine administration in busy orthopedic clinics
- Extensively validated with excellent psychometric properties across diverse knee replacement populations
- Patient-centered focus captures meaningful outcomes rather than only technical surgical success
- Strong responsiveness to knee replacement demonstrating clinically significant improvements
- Knee-specific design; limited applicability to non-surgical knee conditions or generalized lower extremity dysfunction
- Does not assess surgical complications, objective knee stability, or strength measures
- Potential ceiling effects in patients with excellent outcomes; may not distinguish among the best possible results
Common pitfalls
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Applications
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Frequently asked
What is the difference between OKS and OHS?
OKS and OHS are parallel instruments measuring outcomes after knee and hip replacement respectively. Both are 12-item questionnaires with 0-48 score ranges, but contain joint-specific items reflecting unique demands of knee vs. hip function. They cannot be directly compared, and knee replacement patients should use OKS while hip patients use OHS.
How much improvement in OKS score is considered clinically significant?
The minimum clinically important difference (MCID) for OKS is approximately 5 points. Most patients experience improvements of 15-20 points from pre- to post-operative assessment. Patients improving less than 5 points may have suboptimal outcomes warranting further assessment or intervention, whereas improvements exceeding 15 points represent excellent surgical results.
Can OKS be used to predict which patients will have poor knee replacement outcomes?
OKS measures outcome after surgery but does not predict outcomes before surgery. Preoperative OKS is useful for establishing baseline function, but prediction of post-operative results requires additional factors (age, comorbidities, expectations, implant type). Patients with severe preoperative limitations may achieve excellent functional improvement despite moderate post-operative OKS scores.
Sources
- 1.Dawson, J., Fitzpatrick, R., Murray, D., & Carr, A. (1998). Questionnaire on the perceptions of patients about total knee replacement. Journal of Bone and Joint Surgery, 80(1), 63-69.
- 2.Jenkinson, C., Coulter, A., & Bruster, S. (2002). The Picker Patient Experience Questionnaire: development and validation using data from in-patient surveys in five countries. International Journal for Quality in Health Care, 14(5), 353-358.
- 3.Beard, D. J., Harris, K., Dawson, J., Doll, H., Murray, D. W., Carr, A. J., & Price, A. J. (2015). Meaningful changes for the Oxford Hip and Knee Scores after joint replacement surgery. Journal of Clinical Epidemiology, 68(1), 73-79.
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Cite this page
ScholarGate. (2026, June 3). Oxford Knee Score. ScholarGate. https://scholargate.app/health-services/oxford-knee-score