Prognostic Factors of Locking Unicortical System in Internal Fixation for Cervical Spine Lesions

Choi, Gwang Shik; Bae, Jang Ho; Woo, Byung Kil; Kim, Seong Ho; Kim, Oh Lyong; Choi, Byung Yon; Cho, Soo Ho

Abstract

Although anterior cervical plate provide excellent fixation for anterior column, the potential risk for injury to spinal cord or soft tissue has been the reason why they have not gained universal acceptance. For this reason, anterior cervical locking plating systems were designed to avoid such surgical complications. The authors reviewed 98 patients who underwent anterior cervical fusion with anterior cervical locking unicortical system during the period of January 1995 to December 1997. Mean follow up period was 8.4months. Morscher plate placement was done in 24 and Orion plate was applied in 74. We compare the safety and efficacy of these tow plates. The two groups were comparable in demographic details, mean age(Morscher 41, Orion 47) average fusion level(Morscher 1.25, Orion 1.55) and fusion rate(Morscher 95.8%, Orion 100%). For comparison of hardware related complication, two patients(2.7%) showed screw loosening without without need for reoperation in Orion plate group. In Morscher plate group, 1 patient(4.1%) developed plate fracture and 1 patient (4.1%) developed screw loosening, but did not require delete(re) operation. Non-hardware related complications in Morscher group were seen in 2 patients(8.2%): one delete CSF leakage and the other being postoperative hematoma collection. In Orion plate group, complications were developed in 9 patients(12%): two nerve injuries(recurrent laryngeal and hypoglossal nerve), two CSF leakages, two wound infections, one postoperative hematoma collection, two donor graft site pains. Reoperations were done in two cases(2%) due to two postoperative hematoma collection one in Morscher plate group and one in Orion plate group. In one level fusion, longer operation time was required in Morscher plate group(217+/-93.7min) compared to Orion plate group(157+/-47min)(p<0.05). In this study two types of anterior cervical locking plate and screw system had good bony fusion and cervical stabilization with few instrument related complication. Moreover, allograft bone fusion with anterior cervical locking plate and screw system had good solid bony fusion without donor site morbidity. Instrument related complications were more common in Morscher locking plate and screw system.