Preoperative severity of facet joint degeneration does not impact the 2-year clinical outcomes and cervical imbalance following laminoplasty

Background Context

The impact of preoperative facet degeneration (FD) on surgical outcomes following laminoplasty has not been established.

Purpose

To elucidate the influence of preoperative FD on pre and postoperative clinical symptoms and radiographic parameters.

Study Design

Retrospective analysis of prospectively collected data.

Patient Sample

A total of 135 consecutive patients who underwent laminoplasty for cervical spondylotic myelopathy with greater than 2 years follow-up.

Outcome Measures

The cervical Japanese Orthopedic Association score, visual analog scale, Short Form-36, Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire, and radiographic parameters (C7 slope, C2–C7 sagittal vertical axis, C2–C7 lordotic angle, and scoring of FD).

Methods

FD severity of the bilateral facets of C2–3 to C7–T1 was graded using preoperative computer tomography images. Patients were divided into two quantiles according to the mean score of their FD grading: mild (n=69) and severe FD groups (n=66). The preoperative clinical score and radiographic parameters of the two groups were compared. Variables with p<.05 were included in the multinomial logistic regression model. The changes in clinical scores and radiographic parameters between both groups (from the preoperative to 2-year postoperative period) were compared using a mixed-effect model, after adjusting for age and sex.

Results

Mean age and neck pain visual analog scale were independently associated with FD severity (age: p=.004, neck pain: p=.004). However, the other preoperative clinical scores and radiographic parameters were not significantly different. In terms of the change in clinical scores 2 years postlaminoplasty, no significant differences between the severe and mild FD groups were noted. While the mild FD group had a reduced C2–C7 lordotic angle, the severe FD group demonstrated an increased C2–C7 lordotic angle 2 years postlaminoplasty (p=.044). The change in C7 slope and C2–C7 sagittal vertical axis showed no significant differences.

Conclusions

Preoperative FD severity did not influence the 2-year surgical outcomes of laminoplasty, in terms of improvement in myelopathy, patient-oriented score of quality of life, physical and mental status, as well as neck pain. Furthermore, preoperative FD severity correlated with neither preoperative cervical imbalance nor balance deterioration after laminoplasty. These results may encourage physicians to consider laminoplasty for patients with cervical spondylotic myelopathy, regardless of the severity of FD.