Separation of muscle (nontraumatic), left upper arm

This code signifies a non-traumatic detachment or tearing of muscle fibers in the left upper arm. This condition typically arises from overuse, repetitive strain, or degenerative processes rather than an acute injury. It results in pain, weakness, and impaired function of the affected arm.

Apply this code when documentation clearly indicates a spontaneous or atraumatic separation of muscle tissue in the patient's left upper arm. This diagnosis is supported by findings such as muscle atrophy, palpable defect, or imaging (e.g., MRI) confirming muscle discontinuity without evidence of external force or injury.

• Differentiate carefully between non-traumatic and traumatic muscle tears; traumatic tears are coded differently.
• Ensure laterality (left upper arm) is explicitly documented to support this specific code.
• Review documentation for any underlying systemic conditions that may predispose to spontaneous muscle tears, as these may require additional coding.