Plate-only open-door laminoplasty is associated with durable, significantly improved clinical outcomes and a very low reoperation rate for progressive spondylosis or adjacent segment disease: average 8-year follow-up.

BACKGROUND CONTEXT

Multilevel cervical myelopathy is a common cause of spinal cord dysfunction in adults. Surgical intervention via laminoplasty can provide satisfactory clinical outcomes by expansive decompression of the spinal cord. Traditional suture or bone graft techniques have been associated with insufficient fixation, leading to premature closure and subsequent neurological deterioration. In contrast, plated laminoplasty has been shown to provide stable fixation to maintain canal enlargement, but longer-term outcomes are lacking.

PURPOSE

To evaluate longer-term clinical outcomes and reoperations associated with plate-only open-door laminoplasty.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

Postoperative patients who underwent plate-only open door laminoplasty with minimum 5-year follow up.

OUTCOME MEASURES

modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and 12-item Short Form Health Survey (SF-12).

METHODS

All patients at a single academic institution who underwent plate-only open-door cervical laminoplasty from 9/1/2006 to 9/1/2016 were identified to ensure minimum 5 year follow up. Clinical outcomes included the modified Japanese Orthopaedic Association (mJOA) score, the Neck Disability Index (NDI), and the 12-item Short Form Health Survey (SF-12). The occurrence of any repeat operations on the cervical spine was evaluated, as well as its cause. The study team attempted to contact all eligible patients to achieve at least 5 years postoperative follow-up. Pairwise t tests were performed to compare clinical outcomes at preoperative, 6 months, 1-year, and final postoperative follow-up with an α level of 0.05.

RESULTS

A total of 774 met the initial inclusion criteria, of which 157 were included in the study (20.3%). Most common reasons for exclusion included inability to reach after 3 attempts (49.48%), inactive phone numbers (20.28%), and patient declining (3.49%). Included patients had an average age of 60.66±10.63 and an average follow-up time of 8.37±2.57 years (minimum 5 years). mJOA scores (preoperative 11.59±2.16) improved significantly at 6-months (14.57±2.07, p<.001), 1-year (15.19±1.95, p<.001), and final follow-up (14.59±2.63, p<.001). NDI (preoperative 33.89±18.54) improved significantly at 6 months (27.89±19.72, p=.03), 1-year (25.96±19.79, p=.01) and final follow-up (17.88±17.17, p<.001). SF-12 MCS (preoperative 44.73) improved significantly at 6 months (52.01, p=.001), 1-year (51.62, p=.008), and final follow-up (52.32, p<.001). No patient underwent reoperations for plate failure or canal closure with recurrent stenosis. Reoperations for progressive spondylosis during the follow up period were rare and occurred in only three patients for new onset radiculopathy (1.9%) and two patients for myelopathy (1.3%) at an average of 3.2 years postoperative. There were no reoperations performed for adjacent segment disease.

CONCLUSIONS

At a minimum of 5 years and an average of more than 8 years postoperative, laminoplasty was associated with significant and sustained improvements in mJOA, NDI, and SF-12 MCS. Importantly, no patients underwent revision surgery for plate failure or recurrent canal closure. Reoperations for new onset radiculopathy and myelopathy were also very rare over the 8-year average follow-up period, with no reoperations for adjacent segment disease. Plate-only laminoplasty is a durable means of treating multilevel myelopathy with excellent longer-term outcomes and a very low risk of reoperation, either for premature closure or the inevitable spondylotic changes that occur over time in patients with similar baseline characteristics to the study population.