The goals of this research were to characterize the motor recovery of different muscle groups after surgery, establish the pace at which significant preoperative weakness improves, and identify risk factors for failure to improve. The frequency and extent of motor recovery after anterior cervical discectomy and fusion (ACDF) are not well understood, even though ACDF routinely reduces neck and arm pain. 

Researchers looked back at the medical records of people who had 1–4-level ACDF at the same hospital between September 2015 and June 2016. Patients were separated into 2 groups: those with and without severe preoperative weakness (motor grade less than 4 in any single upper extremity muscle group). Muscle groups affected, motor recovery rates, and predictors of poor recovery were all gleaned from patient charts. About 618 patients met the inclusion criteria. About 27 patients (4.5%) had significant upper-extremity weakness before surgery. There was a full recovery of strength in 19 of the affected patients (70.3%), and an improvement in muscle strength in 5 patients (18.5%). Motor recovery after surgery was highest (85.7% in triceps), followed by (83.3%) finger flexors, (83.3%) in hand intrinsics, (50.0%) biceps, (25.0%) deltoids. Myelomalacia (odds ratio: 28.9, P<0.01) and the performance of more than 2 levels of ACDF (odds ratio: 10.1, P<0.01) were risk factors for failing to demonstrate significant motor improvement. 

High rates of motor recovery can be expected after ACDF in patients with severe preoperative upper extremity weakness; however, individuals with deltoid weakness, myelomalacia, and more than 2 levels of ACDF have a lower chance of seeing significant motor improvement.