Dysfunction of the multifidus muscles, lumbar region

This code signifies impaired function or weakness of the multifidus muscles specifically in the lumbar spine. This dysfunction can contribute to chronic low back pain, segmental instability, and altered spinal mechanics. It often presents as atrophy or fatty infiltration of these deep paraspinal muscles.

Apply this code when documentation explicitly states multifidus muscle dysfunction, atrophy, or weakness localized to the lumbar region. Supporting documentation typically includes imaging reports (e.g., MRI showing fatty infiltration), physical therapy evaluations noting multifidus weakness, or physician notes detailing specific muscle findings.

• Ensure the documentation specifies "multifidus" and "lumbar region" to avoid miscoding.
• Do not use for general low back muscle spasm or unspecified muscle weakness; a more specific code would be required.
• Consider sequencing this code after the primary diagnosis for the patient's low back pain (e.g., M54.50) if the multifidus dysfunction is a contributing factor rather than the sole diagnosis.