Postoperative progression and its analysis of ossification of the posterior longitudinal ligament on cervical spine / 中华骨科杂志

ABSTRACT

Objective To investigate and analyze the postoperative progression of ossification of the patients with ossification of the posterior longitudinal ligament (OPLL) on cervical spine. Methods From Jaunary 2001 to December 2007, 95 postoperative patients with cervical OPLL were followed and analyzed retrospectively. There are 72 males, 23 females, with the average age of 56.3 years (range, 40-73years). The follow-up time was from 1 to 6 years, average 3.1 years. Among them 36 patients were performed with anterior cervical corpectomy, fusion with titanium mesh and fixed with cervical plates, others treated with posterior cervical laminectomy and fixation. 2 of the 95 cases were performed anterior and posterior combined operation. Clinical data, X-rays, CT and MR images and progression of ossification, were measured and analyzed in details .The relationships between the progression of ossification and relative factors, as gender, age, C3 ossified involved, T-OPLL, OPLL-type, time of follow-up, surgical approach, Japanese Orthopaedic Association (JOA) scores and improvement rate of JOA scores, were analyzed. Results Progression of ossification in 39 cases among the 95 followed postoperative OPLL patients, 28 men and 11 women, average age 55.9 years, range 41-71 years. The age of progressed patients included 12 cases of ≤49 years, 12of 50-59 years, 12 of 60-69 years and 3 of ≥70 years. 35 patients were operated by posterior approach and only 4 treated with anterior operation. According to the standard of the progression of ossification that 2 mm in the length or/and thickness, there are 4 cases progressed only in length, 2 only in thickness, other 33 patients both the length and thickness. Progression of length is from 2mm to 20mm (average 7.74±4.71). But thickness is progressed from 2 mm to 6 mm (average 2.67±1.51). From 1 to 3 years follow-up time it appeard as a downtrend about the progression of ossification. But it may appear an uptrend from the 4th year. JOA score and improvement rate of the JOA score were almost improved to the high-point in three years. And according to the statistic data there are obvious relationship between progression of ossification with age, surgical approach and C3 ossified involved. Conclusion There is a high rate of postoperative ossification progression in cervical OPLL patients. Cervical OPLL patients with C3 ossification involved, performed with posterior laminectomy and those young at surgery may have higher rate of progression of the ossification. The JOA score and improvement rate of the JOA score were little influenced by the progression of the OPLL during the short and intermediate-term follow-up.