Long-term outcomes of suspension fixation vs miniature titanium plate fixation for laminoplasty in cervical ossification of the posterior longitudinal ligament

English Keywords:Ossification of the posterior longitudinal ligament  Laminoplasty  Titanium plate  Silk thread suspension

English Abstract:

  【Abstract】 Objectives: To compare the long-term outcomes of suspension fixation and miniature titanium plate fixation in cervical ossification of the posterior longitudinal ligament(OPLL). Methods: A total of 173 patients with OPLL who underwent operation from January 2006 to December 2011 were reviewed. The patients were divided into two groups according to different fixation methods. Group A contained 76 cases(44 males and 32 females) who were suspended by silk thread, and group B contained 97 cases(58 males and 39 females) who were fixed by miniature titanium plate. The mean age and follow-up time in group A and group B were 59.8±8.9 years and 83.2±8.8 months, 61.9±6.0 years and 81.2±9.8 months respectively. There was no statistically significant difference of preoperative baseline data such as JOA score, cervical range of motion, and sagittal diameter of spinal canal between the two groups. Preoperative symptoms of cervical spondylotic myelopathy were found in both groups, such as decreased limb strength, unstable walking, and increased muscle tension. We recorded the average operative time, intraoperative blood loss, postoperative complications, and total expense of hospitalization. The followings were acquired at the last follow-up: JOA score, improvements in ROM and sagittal diameter of spinal canal. Results: There was no statistically significant difference of preoperative baseline data between the two groups(P>0.05). In group A, the intraoperative blood loss was 215±20ml, the average operation time was 1.7±0.6h, and the average hospitalization cost was 5.6±0.8 (10, 000 yuan). There were 4 cases of C5 palsy, 8 cases of axial pain and 1 case of close door after surgery. In group B, the above indexes were 217±17ml, 1.8±0.5h and 7.8±1.4 (10, 000 yuan), respectively. There were 7 cases of C5 palsy and 10 cases of axial pain. These complications disappeared within 1 month after systematic conservative treatment. There was no statistically significant difference of operative time, intraoperative blood loss, postoperative complications and JOA improvement rate between the two groups(P>0.05). However, the hospitalization cost of suspension fixation was significantly lower than that of micro-titanium plate fixation(P<0.01). Meanwhile, ROM loss in group A was 8.3°±5.2°, which was lower than 12.1°±6.6° in group B. At the last follow-up, the improvement rate of sagittal diameter in group B was (37.74±3.71)%, which was higher than that in group A[(28.89±4.33)%, P<0.05]. Conclusion: Both wire suspension and micro-titanium plate fixations can achieve satisfactory long-term outcomes in OPLL. Suspension fixation was associated with better maintenance of cervical range of motion and lower hospitalization costs, while micro-titanium plate fixation obtains better maintenance of sagittal diameter of spinal canal.