Correlated evaluation on the spinal segment motion scope and the alteration of the corre sponding parameters after artificial lumbar intervertebral disc replacement

doi:10.3321/j.issn:1673-8225.2004.32.012

Abstract：BACKGROUND: Intervertebral discs are often destroyed by physiological aging and pathological damages. The results may cause not only disc degenerative diseases, but also serial changes of spinal biomechanics because intervertebral discs are key structures in the spinal motion segment. So it is better to reconstruct the normal function of the destroyed disc, which not only can treat disc degenerative diseases but also restore its function partly.OBJECTIVE: To explore the motion scope and the alterations of the corresponding parameters of the corresponding spinal segment after artificial disc replacement(ADR) in patients with degenerative diseases of lumbar intervertebral disc.DESIGN: A before-after controlled study.SETTING: Department of Orthopaedics, the Third Affiliated Hospital and Department of Orthopaedics, the Second Affiliated Hospital of Sun Yat-sen University.PARTICIPANTS: The study was principally performed in the Department of Orthopaedics of the Second Affiliated Hospital of Sun Yat-sen University. Thirty-four patients diagnosed with degenerative diseases of lumbar intervertebral disc were selected for our study during February 1999 to June 2002. Artificial disc replacement was performed in 41 intervertebral discs. All patients completed the whole process of the study according to the postoperative requirement.METHODS: All the patients received ADR with SB Charite Ⅲ artificial lumbar intervertebral disc(AID) made by Link Company, Germany, made through an anterior extraperitoneal approach under endotracheal anaesthesia after pararectal incision, and relative evaluations as well.tor segment, motor scope of the intervertebral articulation, the height of inpostoperative clinical effectivenessRESULTS: Single segment replacement was performed in 2 cases of I3-44, 18cases of L4-5, and 7 cases of L6S1, and two-segment replacement was performed in 1 case of L3-4 combined with L4-5 and 6 cases of L4-5 combined with L6S1. All patients received postoperative follow-up for a period of 3 to 38 months(average of 18.6 months) with a total excellent or good ratio of 90%. No abnormal dislocation was found in 4 cases of lumbar disc herniation (LDH) with lumbar spinal instability by postoperative lumbar dynamic film, which proved that the operation reconstructed the lumbar stability. No instable segments were found in other operated cases. The postoperative extension and flexion scope of L4-5showed no significant difference compared with that of the control group(P＞ 0.05) . Measurement only performed in 15 cases of L4-5 segment ADR accompanied with Ⅰ- Ⅱ° stenosis in intervertebral space with the results proved that there were significant differences in the height of the intervertebral space and the size of the intervertebral foramen before and after operation( t =2. 547, 2. 634, P＜0.05).CONCLUSION: ADR for lumbar intervertebral disc-derived diseases can reconstruct the height of intervertebral space, enlarge the size of intervertebrai foramen, and to increase the motor scope of the spinal segments, except the restoration of the motor function of the lumbar segments.