KOOS Assessment Calculator
Pain
These questions concern the amount of knee pain you experienced during the last week.
1. How often do you experience knee pain?
2. Twisting/pivoting on your knee
3. Straightening knee fully
4. Bending knee fully
5. Walking on flat surface
6. Going up or down stairs
7. At night while in bed
8. Sitting or lying
9. Standing upright
What is the KOOS Assessment?
The Knee Injury and Osteoarthritis Outcome Score (KOOS) is a patient-reported outcome measurement instrument developed to assess patients' opinions about their knee problems. It evaluates both short-term and long-term consequences of knee injury and primary osteoarthritis.
Purpose and Applications
The KOOS is widely used in clinical settings and research to:
- Monitor knee pain and symptoms over time
- Evaluate recovery after knee injuries or surgeries
- Assess treatment outcomes for knee osteoarthritis
- Track functional limitations in daily activities and sports
- Measure knee-related quality of life
The Five KOOS Subscales
Pain
Evaluates pain frequency and severity during various activities like walking, stairs, rest, and standing.
Symptoms
Assesses knee stiffness, swelling, grinding, catching, and range of motion limitations.
Activities of Daily Living (ADL)
Measures function in everyday activities like stair climbing, standing, bending, walking, and getting in/out of cars.
Sport and Recreation Function
Evaluates difficulties with more demanding activities like squatting, running, jumping, and pivoting.
Knee-related Quality of Life
Assesses awareness of knee problems, lifestyle modifications, confidence, and overall difficulties due to the knee.
Interpreting KOOS Scores
Each KOOS subscale is scored from 0 to 100, where:
- 0 points: Extreme knee problems
- 100 points: No knee problems
The scores can be interpreted as follows:
| Score Range | Interpretation |
|---|---|
| 80-100 | Excellent function, minimal symptoms |
| 60-79 | Good function, some symptoms |
| 40-59 | Moderate function, moderate symptoms |
| 20-39 | Poor function, significant symptoms |
| 0-19 | Severe dysfunction, extreme symptoms |
Clinical Significance
The minimal clinically important difference (MCID) for the KOOS is typically considered to be 8-10 points. This means that a change of 8-10 points or more in any subscale represents a meaningful improvement or deterioration from the patient's perspective.
Using the KOOS in Medical Billing
The KOOS assessment can be used in medical billing as part of:
- Initial evaluations for knee conditions (CPT codes 97161-97163)
- Re-evaluations to document progress (CPT code 97164)
- Outcome reporting for quality measures
- Documentation for medical necessity of continued treatment
- Supporting functional improvement for insurance authorization
Medical Billing Tip
When using the KOOS for medical billing, ensure you document the specific subscale scores and total score in your assessment. Include a brief interpretation of how the scores impact the patient's function and your treatment plan. This strengthens your documentation for reimbursement.
References
- Roos EM, Lohmander LS. The Knee injury and Osteoarthritis Outcome Score (KOOS): from joint injury to osteoarthritis. Health Qual Life Outcomes. 2003;1:64.
- Collins NJ, Prinsen CA, Christensen R, Bartels EM, Terwee CB, Roos EM. Knee Injury and Osteoarthritis Outcome Score (KOOS): systematic review and meta-analysis of measurement properties. Osteoarthritis Cartilage. 2016;24(8):1317-1329.
- American Academy of Orthopaedic Surgeons. AAOS Clinical Practice Guideline: Treatment of Osteoarthritis of the Knee. 2nd ed. 2013.