Changes in Neck Range of Motion After Laminoplasty Based on Cervical Foraminal Stenosis.

STUDY

DESIGN

Retrospective study.

OBJECTIVE

To investigate the relationship between a number of preoperative cervical foraminal stenoses and postoperative ROM in cervical laminoplasty patients.

SUMMARY OF BACKGROUND DATA: Several concerns exist, such as upper extremity palsy, kyphosis, axial neck pain, and ROM changes after laminoplasty. Preoperative foraminal stenosis is a known risk factor for upper extremity palsy and kyphosis after laminoplasty.

METHODS

Open-door laminoplasty patients with cervical myelopathy between January 2007 and September 2021 were included. Foraminal stenosis was evaluated using MRI T2-weighted images of the axial cut. The number of foraminal stenoses was counted among 10 foramina from C3/C4 to C7/T1, and the study population was divided into 2 groups based on the number of foraminal stenoses. Groups A and B comprised individuals with <4 and 4 or more foraminal stenoses, respectively. ROM was measured through flexion and extension view plain lateral radiography using Cobb method. NDI and VAS scores were used to assess clinical symptoms. Cervical spondylosis was assessed with Cervical Degenerative Index (CDI) factor scoring system. Statistical analyses were performed using 2-sample t test, χ 2 test, and linear mixed model.

RESULTS

Sixty-three patients (group A, 27; group B, 36) were analyzed. NDI score after 1 year was 18.33 and 19.29 in groups A and B ( P =0.027). Regarding neck pain, VAS score after 3 years of surgery was 1.55 in group A and 3.94 in group B ( P =0.043). Flexion and total ROM in group A, 3 years post-surgery were 24.59 and 36.2 degrees, and group B had values of 16.04 and 24.98 degrees, respectively ( P =0.014). Three years after surgery, ROM preservation ratio was 89% in group A and 66% in group B ( P =0.013). On the basis of the CDI factor scoring system, difference of average between groups was 1.02 ( P =0.081).

CONCLUSIONS

A greater number of foraminal stenoses results in a reduction in ROM after laminoplasty.

LEVEL OF EVIDENCE: Level III.