Untreated knee pain triggers muscle loss in thigh and hip

Knee pain is often dismissed as a natural part of aging, but studies have shown that if left untreated, it can cause severe damage to the muscles of the thigh and hip.

Early treatment to control the pain and proper muscle rehabilitation is the key to restoring daily function and even prognosis after surgery.

Samsung Changwon Hospital announced on Thursday that a research team, led by Professor Lee Do-kyung of the hospital's Department of Orthopedic Surgery and Professor Yoo Jun-il of Inha University Hospital's Department of Orthopedic Surgery, conducted a detailed analysis of CT images of 89 patients with knee osteoarthritis from June 2021 to May 2024.

They found that the painful legs of patients with knee osteoarthritis showed a decrease in muscle mass and intramuscular fat deposition, a phenomenon known as muscle deterioration.

In general, knee osteoarthritis treatment has focused on pain relief through medications, injections, and surgery. However, this study provides new evidence that knee osteoarthritis treatment should be combined with rehabilitation for specific muscle atrophy.

The analysis showed that the quadriceps (front thigh muscle) and gluteus maximus (buttock muscle) tended to be selectively atrophied in legs with knee pain. The researchers emphasized the need for customized rehabilitation treatments that focus on strengthening these muscles.

The researchers also noted that knee osteoarthritis should be understood as a systemic disease, not just a joint disease, which together deteriorates the quantity and quality of lower extremity muscles, promoting sarcopenia.

If rehabilitation is initiated after severe muscle damage, it can lead to a slow recovery and persistent daily discomfort, including difficulty climbing and descending stairs, knee weakness, and stumbling, as well as an increased risk of falls and fractures.

“Knee osteoarthritis pain can lead to structural damage and loss of function beyond just muscle weakness,” Professor Lee said. “Early pain control and appropriate muscle rehabilitation can improve daily function and postoperative outcomes.”