Surgical Treatment of Degenerative-Dystrophic Diseases of Lumbosacral Spine: Orthopedic Aspects

A.K. Dulaev, V.P. Orlov, K.A. Nadulich, V.A. Averkiev, A.V. Teremshonok

Chair of Traumatology and Orthopedics, Medicomilitary Academy, Saint Petersburg, Russia

 

We analyzed the nearest and remote results (3-9 years) of conventional surgical treatment (discectomy) of 278 patients with degenerative-dystrophic diseases of the lumbosacral spine and pain vertebrogenic and radicular syndromes. The mean age was 37 years (18-75). The majority of patients (243) underwent single-level discectomy; it was made at two levels in the rest cases. Different types of laminectomy were used in approaching a disc. Estimation of the nearest outcomes showed, that good and positive results (arrest of radicular and vertebrogenic syndromes, restoration of working ability) were present in 92% of cases. At the same time study of remote results was indicative of considerable reduction of favorable outcomes (up to 72%). The data of anamnesis allowed to find out, that complaints appeared in the majority of patients during 2-4 years after operations. Multimodality examination (conventional and functional rentgenography, positive myelography, CT, MRI) and the analysis of clinical results demonstrated main pathologic factors, responsible for preservation or development of persistent vertebrogenic or radicular syndromes and caudopathy symptoms in a remote postoperative period.
These factors were as follows:
1. Compression of neurovascular elements by hernia of an intervertebral disc (a relapse or hernia formation in adjacent discs), stenosis of a vertebral canal.
2. Chronic instability of a vertebral-motor segment (VMS).
3. An impaired sagittal profile (considerable reduction of lordosis), manifesting itself in static disorders.
4. A combination of the above factors.

The first and second factors were subdivided into the following two groups with the purpose of more precise and detailed estimation: 1a - local compression of a nerve root (hernia of an intervertebral disc, lateral stenosis of an intervertebral canal, stenosis of an intervertebral foramen and 1b - poliradicular compression (central stenosis of an intervertebral canal); 2a - hypermobility of VMS (anteroposterior disclocation of vertebrae up to 3 mm and increase of an angle between adjacent laminas of vertebral arches, watched at functional rentgenography, which does not exceed 10o) and 2b - genuine instability of VMS.

The obtained data were used by us in our subsequent study for determining a target (decompression of neurovascular elements and (or) elimination of segmental instability of the spine with (without) restoration of a sagittal profile) and elaborating an individual program of surgical treatment (different methods of decompresson of the spinal cord elements and its roots, instrumental and osteoplastic correction and stabilization of the spine).

Our experience is based on surgical treatment of 153 patients with degenerative-dystrophic diseases of the lumbosacral spine, carried out at the Chair of Traumatology and Orthopedics of the Medicomilitary Academy in 1997-2001. A pathology spectrum included hernias of intervertebral discs (59), different types of degenerative stenosis of a vertebral canal (58), chronic instability of vertebral segments (15) and degenerative spodylolisthesis (21).

A stage of planning comprised estimation of main pathologic factors and analysis of adjacent VMS with the purpose of revealing pre-manifestation signs of their lesion (disc protrusion, instability, spondylarthrosis).

Local (microsurgical) decompressive methods (interlaminectomy, isthmotomy, fenestration of an arch's laminar part) were used in local forms of compression of neurovascular elements of the spinal cord. Laminectomy with sparing resection of articular processes on both sides (up to 50%) was performed in central stenosis. This pathology was more typical of people above 55-60. Stability of VMS was often ensured by accompanying fibrosis of an intervertebral disc, deforming spondylosis, etc.).

In case of VMS hypermobility, typical of young individuals, it was eliminated by instrumental fixation.

VMS instability demanded instrumental fixation, combined with osteoplastic spondylodesis (posterolateral PLF, interbody PLIF, spondylodesis of 360o TLIF). Restoration of a sagittal profile of the lumbosacral spine was achieved by contraction of posterior vertebral segments (lordosis restoration), performed after decompression.

When there were combined pathologic factors, a method of opsteoplastic stabilization of the spine was dependent on its stability. We took into account not only initial instability, but also a degree of impairment of segmental stability, which appeared during intervention due to resection of structures of the posterior supporting complex. Instrumental fixation was always combined with posterolateral spondylodesis in 2-3-level disectomy in young patients. Presence of marked degenerative changes at an adjacent level was an indication for instrumental fixation of this segment.

Use of rational surgical tactics in treatment of degenerative-dystrophic disorders of the lumbosacral spine allowed to get excellent and good anatomic-functional results (a follow-up of 2-5 years) in the majority of patients (142, 92.8%). Satisfactory and bad results were watched in 8 (5.2%) and 3 (2%) of cases respectively.