Reliability of ultrasound strain elastography in the assessment of the quadriceps and patellar tendon in healthy adults.

Strain elastography of the patellar tendon is more reliable than the quadriceps tendon. Intra- and inter-operator reliability was better when undertaken by more experienced operators. Colour scoring was more reliable than elasticity ratio and index methods. Poor-fair intra- and inter-operator reliability of the elasticity ratio and elasticity index was observed.