Selective Electrical Muscle Stimulation of the Vastus Medialis in a Patient With Knee Osteoarthritis, With Changes in Muscle Quality, Symptoms, and Physical Activity: A Case Report.
Yoshitsugu Tanino, Yuki Fukumoto, Tatsuya Kono et al.
✦ AI-curated · Sources linked
Case in brief
A 77-year-old man with Kellgren-Lawrence grade 2 right knee osteoarthritis had stopped regular exercise, including aquatic walking, because of knee pain. He received electrical stimulation of the vastus medialis for 30 minutes per session, three times weekly for four weeks. After the intervention, ultrasound echo intensity—a proxy for intramuscular fat—was 13.7 arbitrary units (25.3%) lower than before, and his Knee Injury and Osteoarthritis Outcome Score improved. He resumed aquatic walking two weeks after stimulation began. As a single uncontrolled case, the observed changes cannot be attributed to stimulation alone.
What made this case unusual
The case tracked both ultrasound echo intensity, an indirect measure of muscle fat, and patient-reported knee outcomes during selective vastus medialis stimulation; however, the patient resumed aquatic walking during the intervention, complicating interpretation.
Diagnostic / clinical pearl
A change in ultrasound echo intensity is an indirect indicator of intramuscular fat, not a direct measure. In this case, concurrent return to physical activity means symptom and imaging changes cannot be assigned to electrical stimulation alone.