M61.9: Calcification and ossification of muscle, unspecified

Calcification and ossification of muscle, or muscle calcinosis, is a condition defined by the abnormal deposit of calcium and the process of bone tissue formation within the muscle tissue. This anomalous process often occurs in response to injury, inflammation, or a systemic disease, such as connective tissue disorders. The involved muscle may harden due to the calcium deposits and bone tissue providing a framework, which can limit movement and produce pain. Overtime, small lumps may develop under the skin surface, especially if the calcium deposits are significant. Chronic muscle inflammation is a key factor that contributes to disease progression. Majorly, large muscles are targeted such as the thighs and upper arms. Muscle functionality and the skeletal system are primarily affected in this condition.