What are the cutoff scores for a problematic knee on the ADL subscale for KOOS?

• A. ADL <86.8
• B. ADL <85.0
• C. ADL <90.0
• D. ADL <80.0

Answer: (A)

The key idea is how KOOS ADL is used to flag functional problems in daily activities. The ADL subscale runs from 0 to 100, with higher scores showing better daily function. To decide if a knee is problematic, a cutpoint is chosen to separate those with meaningful daily-living limitations from those without. A commonly cited threshold is 86.8, so scores below 86.8 indicate a knee with problematic daily functioning. This cutoff is derived to balance sensitivity and specificity in identifying knees that truly impact daily activities. The other numerical options are not the validated threshold, so they don’t align with how the ADL score is used to define a problematic knee.