Impact of wedge-shaped resection of the posterior bony arch on postoperative outcomes after open door laminoplasty in the cervical spine: a 2-year follow-up study.

BACKGROUND CONTEXT

Open door laminoplasty (ODLP) can also lead to significant postoperative motion restriction that further increases over time, for which one of the possible factors is the bony impingement between neighboring posterior bony arches. Previously, we reported this phenomenon and modified technique of ODLP, wedge-shaped resection of the posterior bony arch that produced greater range of motion (ROM) of the cervical spine and less posterior neck pain compared with conventional ODLP (cODLP) in 1-year follow-up time, but no longer follow-up outcomes of the surgical technique has been reported.

PURPOSE

The study aimed to thoroughly evaluate the impact of posterior bony impingement following ODLP on postoperative cervical motion and related outcomes, and to compare postoperative outcomes of conventional ODLP (cODLP with those of modified ODLP (mODLP) in 2-year follow-up times.

STUDY DESIGN

This is a retrospective comparative study.

PATIENT SAMPLE

A total of 145 patients who underwent cODLP or mODLP and were followed up for at least 2 years were classified into two groups: Group A (cODLP, 79 patients) and Group B (mODLP, 66 patients).

OUTCOME MEASURES

The primary outcome measure was ROM of the cervical spine. Secondary outcome measures included (1) patient satisfaction, (2) radiological outcomes, including the rate of bony impingement and spontaneous fusion, and bone regrowth of the resection site, (3) clinical outcomes based on pain intensity and scores on the 12-item short-form health survey (SF-12) and neck disability index (NDI), (4) surgical outcomes, and (5) surgery-related complications.

METHODS

We compared baseline data in both groups. To evaluate the impact of our surgical modification on postoperative outcome after ODLP, we compared the outcome measures in 2-year follow-up times. No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.

RESULTS

The ROM of the cervical spine was significantly greater in Group B 2 years after surgery than in Group A (p=.001). Patient satisfaction (p=.02) at 2 years after surgery and pain intensity of the posterior neck at 1 (p=.01) and 2 years (p<.01) after surgery were better in Group B than in Group A. Radiological evidence of posterior bony impingement and spontaneous fusion between ODLPsegments were definitely fewer less in Group B than in Group A (p<.001 and<0.001, respectively). The mean value of bone regrowth was 1.2 mm (range, 0-3 mm). The NDI and SF-12 scores did not differ significantly between groups. Surgical outcomes and postoperative complications were similar between groups.

CONCLUSIONS

These results indicate that posterior bony impingement can be a factor in ROM restriction after cODLP surgery and that wedge-shaped resection during ODLP can be a reliable option for preserving cervical ROM and improving postoperative clinical and radiological outcomes.