Identification of Risk Factors for Long-Term Surgical Outcomes Following Laminoplasty for Cervical Ossification of the Posterior Longitudinal Ligament

Abstract

Study DesignRetrospective multi-institutional study.ObjectivesAlthough previous studies have evaluated the surgical outcomes of laminoplasty in patients with cervical ossification of the posterior longitudinal ligament (OPLL), the long-term results remain unclear. The purpose of this study is to assess outcomes more than 10 years post-surgery and identify to identify factors that affect the long-term prognosis.MethodsEighty-four OPLL patients with more than a minimum of 10-year follow-up after surgery were divided into a good group with more than 50% improvement of the recovery rate of the cervical Japanese Orthopaedic Association (JOA) score, and a poor group with less than 50% improvement. The demographic data and radiographic parameters of cervical spinal alignment were compared, and significant poor prognostic factors were evaluated by multivariate logistic regression.ResultsFour preoperative factors showed significant differences between 2 groups: the presence of type 2 diabetes (P = 0.012), the baseline JOA scores (P = 0.001), the narrowest segment in the cervical (P < 0.001) and the presence of T2-weighted high signal on MRI (P = 0.030). Logistic regression analysis identified 3 of 4 factors were significantly associated with postoperative poor outcomes: the presence of type 2 diabetes (P = 0.011), the baseline JOA scores (P = 0.022), and the presence of T2-weighted high signal on MRI (P = 0.035).ConclusionThis study identified three risk factors associated with poor long-term surgical outcomes following laminoplasty for cervical OPLL. These findings could be significant indicators for predicting long-term outcomes in cervical OPLL patients.

Keywords: cervical ossification of longitudinal ligament; long term follow-up; myelopathy; spine surgery; surgical outcome.

Figure 1.

Changes of cervical alignment parameters and cervical JOA score before surgery, at 2-year follow-up and at final follow-up. (A)Intermediate C2 –C7 angle, (B) C7 slope, (C) C2 –C7 SVA, (D) Cervical ROM. * represents the significance between before surgery and 2-year follow-up scores, before surgery and final follow-up scores and 2-year and final follow-up scores in GG and PG, respectively. # represents the significance between GG and PG before surgery, at 2-year follow-up and final follow-up, respectively; SVA, sagittal vertical axis; ROM, range of motion; *, P < 0.05.

Figure 2.

Changes of cervical JOA score before surgery, at 2-year follow-up and at final follow-up. * represents the significance between before surgery and 2-year follow-up scores, before surgery and final follow-up scores and 2-year and final follow-up scores in GG and PG, respectively. # represents the significance between GG and PG before surgery, at 2-year follow-up and final follow-up, respectively. JOA indicates Japan Orthopaedic Association; *, P < 0.05; #, P < 0.05.