New Scoring System Proposed for Knee Ultrasound

November 24, 2014

A proposed five-point system for diagnostic scoring of knee osteoarthritis by ultrasound could resolve problems of operator inconsistency.

Riecke BF, Christensen R, Torp-Pedersen S, et al. An ultrasound score for knee osteoarthritis: a cross-sectional validation study.Osteoarthritis and Cartilage. 2014 22:1675-1691. doi: 10.1016/j.joca.2014.06.020.

Observer or operator dependence limits the value of ultrasound for diagnosing osteoarthritis (OA), but a proposed standardized diagnostic scoring method could correct that.

An ultrasound scoring system proves reliable and reproducible, according to its Danish developers. The system ranks five areas in knee OA:

  • Medial compartment morphological changes,
  • Inflammation in the medial compartment,
  • Lateral compartment morphological changes,
  • Inflammation in the lateral compartment, and
  • Effusion.

These researchers from Copenhagen University's Parker Institute, who are engaged in long-term studies of the effects of weight loss on knee OA, compared their scoring system with x-ray and the Knee Injury and Osteoarthritis Outcome Score (KOOS) for ability to discern degrees of knee OA. For the five domains, the ultrasound scores showed "substantial" reproducibility, they say.

"The score detected all aspects of knee OA with relevant precision” superior to radiography, the authors say, while noting that ultrasound cannot identify early cartilage damage.