Recovery Process After Anterior Cervical Decompression in Patients With Cervical Spondylotic Myelopathy With Different Natural History.

Abstract

An observational prospective cohort study. To investigate the influence of natural history on the recovery of patients with cervical spondylotic myelopathy (CSM) after anterior cervical decompression. The natural history of CSM has not been clearly elucidated, it remains unclear whether the natural history of CSM is associated with the recovery process after surgical treatment. Patients with CSM (n=117) after anterior cervical decompression were stratified variously on the basis of natural history features. Baseline and postoperative neurological functions were rated using the Japanese Orthopaedic Association (JOA) and patient-based self-evaluation (PBSE) scores. The minimum and maximum recovery times for sensory function, and motor functions of the upper and lower extremities were analyzed separately at time points 1-60 months after surgery. In all patients, the postoperative JOA and PBSE scores were significantly improved relative to baseline, in which sensory function recovered most quickly, followed by upper-extremity and lower-extremity motor functions. However, when compared with patients whose first symptom onset at the lower extremity, patients with the first onset at the upper extremity required less time to recover lower-extremity motor function, but more time to recover upper-extremity motor function. Patients with rapid progression had significantly lower preoperative and final JOA and PBSE scores compared with patients whose progression was steady or stepwise. Patients with preoperative symptoms ≥1 year had longer recovery time and poorer functional outcomes compared with those symptoms <1 year. In patients with CSM, the location of first symptom onset, progressive velocity of symptom, and duration of preoperative symptoms significantly influenced the recovery process after anterior cervical decompression. Level 2-observational prospective study.