Laminectomy and fusion versus laminoplasty for the treatment of degenerative cervical myelopathy: results from the AOSpine North America and International prospective multicenter studies

Background Context

It remains unclear whether cervical laminoplasty (LP) offers advantages over cervical laminectomy and fusion (LF) in patients undergoing posterior decompression for degenerative cervical myelopathy (DCM).

Purpose

The objective of this study is to compare outcomes of LP and LF.

Study Design/Setting

This is a multicenter international prospective cohort study.

Patient Sample

A total of 266 surgically treated symptomatic DCM patients undergoing cervical decompression using LP (N=100) or LF (N=166) were included.

Outcome Measures

The outcome measures were the modified Japanese Orthopaedic Association score (mJOA), Nurick grade, Neck Disability Index (NDI), Short-Form 36v2 (SF36v2), length of hospital stay, length of stay in the intensive care unit, treatment complications, and reoperations.

Methods

Differences in outcomes between the LP and LF groups were analyzed by analysis of variance and analysis of covariance. The dependent variable in all analyses was the change score between baseline and 24-month follow-up, and the independent variable was surgical procedure (LP or LF). In the analysis of covariance, outcomes were compared between cohorts while adjusting for gender, age, smoking, number of operative levels, duration of symptoms, geographic region, and baseline scores.

Results

There were no differences in age, gender, smoking status, number of operated levels, and baseline Nurick, NDI, and SF36v2 scores between the LP and LF groups. Preoperative mJOA was lower in the LP compared with the LF group (11.52±2.77 and 12.30±2.85, respectively, p=.0297). Patients in both groups showed significant improvements in mJOA, Nurick grade, NDI, and SF36v2 physical and mental health component scores 24 months after surgery (p<.0001). At 24 months, mJOA scores improved by 3.49 (95% confidence interval [CI]: 2.84, 4.13) in the LP group compared with 2.39 (95% CI: 1.91, 2.86) in the LF group (p=.0069). Nurick grades improved by 1.57 (95% CI: 1.23, 1.90) in the LP group and 1.18 (95% CI: 0.92, 1.44) in the LF group (p=.0770). There were no differences between the groups with respect to NDI and SF36v2 outcomes. After adjustment for preoperative characteristics, surgical factors and geographic region, the differences in mJOA between surgical groups were no longer significant. The rate of treatment-related complications in the LF group was 28.31% compared with 21.00% in the LP group (p=.1079).

Conclusions

Both LP and LF are effective at improving clinical disease severity, functional status, and quality of life in patients with DCM. In an unadjusted analysis, patients treated with LP achieved greater improvements on the mJOA at 24-month follow-up than those who received LF; however, these differences were insignificant following adjustment for relevant confounders.