Clinical efficacy of posterior surgery for cervical ossification of posterior longitudinal ligament with K-line positive in extension radiograph

CHEN Dechun; CHEN Yu; CHEN Deyu

doi:10.3969/j.issn.1674-666X.2014.05.001

Abstract：Objective To evaluate the clinical effects of posterior surgery for cervical ossification of posterior longitudinal ligament (OPLL) with K-line positive in extension lateral X-ray film. Methods Seventy-two patients with cervical OPLL underwent posterior laminoplasty (27 patients) or laminectomy (45 cases) in Changzheng Hospital of the Second Military Medical University from February 2005 to January 2012, and their clinical data were reviewed retrospectively. According to the position relation of K-line and the range of OPLL, patients were classified into 2 groups, K-line positive group (OPLL not beyond K-line, 39 cases) and group of K-line positive in extension radiograph (OPLL beyond K-line in normal lateral X-ray film but not beyond K-line in extension lateral film, 33 cases). Japanese Orthopaedic Association (JOA) scores before surgery and 1 year after surgery were recorded, the improvement rate was calculated. Results Average of JOA score in K-line positive group was improved from preoperative (11.3 ± 2.9) to (14.2 ± 3.0) at 1 year after operation (P<0.05), the average score in group of K-line positive in extension radiograph was also improved from preoperative (10.5 ± 1.8) to (13.3 ± 2.7) at 1 year after operation (P <0.05); While the differences of preoperative, postoperative JOA scores between two groups had no statistical significance respectively (P >0.05). The mean improvement rate was (51 ± 22) % in K-line positive group and (44 ± 23) % in group of K-line positive in extension radiograph, there is no statistical difference between two groups (P >0.05). Conclusion Cervical OPLL patients with K-line positive in extension X-ray film could achieve similar clinical outcome compared with K-line positive patients.