Fatty infiltration of the cervical multifidus musculature and their clinical correlates in spondylotic myelopathy.

•MFI, the pathological infiltration of fatty tissue into muscle, may contribute to pain and disability in patients with CSM.•Patients with CSM have higher levels of MFI than age-matched controls.•Increased MFI of the multifidus muscles is associated with clinically significant changes in mJOA and Nurick scores.•Spinal injury in CSM may lead to secondary muscle loss and muscle fat infiltration.