Long-term Outcomes of 2 Cervical Laminoplasty Methods

Abstract

Two major current methods are midline splitting laminoplasty (MSL) and unilateral single-door laminoplasty (USDL). Few studies have compared the 2 techniques. We retrospectively analyzed the outcomes of 100 consecutive myelopathy patients who underwent decompressive laminoplasty between January 2004 and June 2008. The mean follow-up duration was 48.2 months. The mean Japanese Orthopedic Association scores changed from 6.9 to 11.9 in the MSL group and from 6.2 to 12.4 in the USDL group, resulting in mean calculated recovery rates of 55.5% and 63.0%, respectively (P = 0.14). Mean cervical lordosis declined from 12.0 to 10.2 degrees in the MSL group and from 10.3 to 8.5 degrees in the USDL group (P = 0.24). Mean cervical range of motion declined from 27.8 to 25.6 degrees in the MSL group, and from 23.4 to 16.0 degrees in the USDL group (P = 0.38). Bony spinal canal dimension increased from 201.2 to 280.8 mm in the MSL group and from 204.3 to 331.7 mm in the USDL group (P < 0.001). In the USDL group, 6 patients experienced postoperative neck pain, 7 experienced C5 palsy, and 2 experienced cerebrospinal fluid leakage. No such complications occurred in the MSL group (P ≥ 0.05 for both complications). MSL and USDL patients had similar long-term clinical and radiologic outcomes, except that bony canal expansion was greater in the latter. We believe that removal of the ligamentum flavum and drilling of the internal bony edge were factors in the favorable clinical outcomes and low rate of complications in the MSL group.