No abstract available.
Zygapophyseal Joint*

OBJECTIVES: An in vitro biomechanical study of posterior lumbar interbody fusion(PLIF) with threaded cage using two different approaches was performed on eighteen functional spinal units of bovine lumbar spines. The purpose of this study was to compare the segmental stiffnesses among PLIF with one long posterolateral cage, PLIF with one long posterolateral cage and simultaneous facet joint fixation, and PLIF with two posterior cages. METHODS: Eighteen bovine lumbar functional spinal units were divided into three groups. All specimens were tested intact and with cage insertion. Group 1(n=12) had a long threaded cage(15x36mm) inserted posterolaterally and oriented counter anterolaterally on the left side by posterior approach with left unilateral facetectomy. Group 2(n=6) had two regular length cages(15x24mm) inserted posteriorly with bilateral facetectomy. Six specimens from group 1 were then retested after unilateral facet joint screw fixation in neutral(group 3). Likewise, the other six specimens from group 1 were retested after fixation with a facet joint screw in an extended position(group 4). Nondestructive tests were performed in pure compression, flexion, extension, lateral bending, and torsion. RESULTS: PLIF with a single cage, group 1, had a significantly higher stiffnesses than PLIF with two cages, group 2, in left and right torsion(p<0.05). Group 1 showed higher stiffness values than group 2 in pure compression, flexion, left and right bending but were not significantly different. Group 3 showed a significant increase in stiffness in comparison to group 1 for pure compression, extension, left bending and right torsion(p<0.05). For group 4, the stiffness significantly increased in comparison to group 1 for extension, flexion and right torsion(p<0.05). Although there was no significant difference between groups 3 and 4, group 4 had increased stiffness in extension, flexion, right bending and torsion. CONCLUSION: Posterior lumbar interbody fusion with a single long threaded cage inserted posterolaterally with unilateral facetectomy enables sufficient decompression while maintaining a majority of the posterior elements. In combination with a facet joint screw fixation, adequate postoperative stability can be achieved. We suggest that posterolateral insertion of a long threaded cage is biomechanically an ideal alternative to PLIF.
Decompression ; Spine ; Zygapophyseal Joint

No abstract available.
Spine* ; Zygapophyseal Joint*

No abstract available.
Intervertebral Disc* ; Zygapophyseal Joint*

No abstract available.
Spondylolisthesis* ; Zygapophyseal Joint*

No abstract available.
Prolapse ; Tropism ; Zygapophyseal Joint

No abstract available.
Prolapse ; Tropism ; Zygapophyseal Joint

Although posterior segmental fixation technique is becoming increasingly popular, surgical treatment of craniovertebral junctional disorders is still challenging because of its complex anatomy and surrounding critical neurovascular structures. Basilar invagination is major pathology of craniovertebral junction that has been a subject of clinical interest because of its various clinical presentations and difficulty of treatment. Most authors recommend a posterior occipitocervical fixation following transoral decompression or posterior decompression and occipitocervical fixation. However, both surgical modalities inadvertently sacrifice C0-1 and C1-2 joint motion. We report two cases of basilar invagination reduced by the vertical distraction between C1-2 facet joint. We reduced the C1-2 joint in an anatomical position and fused the joint with iliac bone graft and C1-2 segmental fixation using the polyaxial screws and rods C-1 lateral mass and the C-2 pedicle.
Decompression ; Joints ; Transplants ; Zygapophyseal Joint

This study analyzed 88 patients who sustained a cervical spine injury during the past 4 years(Jan, 1993-May, 1996) in whom had 33 anterior, 21 posterior interventions were underwent and 34 remaining patients recieved conservative treatment with halovest. In 45 cases of upper cervical injuries, 16 operations were done. Among these, anterior approach was used in 3 patients and posterior approach in 13 patients. In 43 cases of lower cervical injuries, 39 operations were done. The anterior approach was used in 30 patients, posterior approach in 9 patients, and bilateral approached in remaing 4 cases. For patients with a predominent posterior ligamentous or osteoligamentous lesion, we selected anterior approach, when closed reduction was possible. Whenever the facet joint remained interlocked, a posterior approach was chosen. This report does not mentioned priority of anterior procedure at any case. Although clinical experience does not support the experimental data, we examined the reliability of anterior approach with use of internal fixation.
Humans ; Ligaments ; Spine* ; Zygapophyseal Joint

OBJECTIVE: We evaluated postoperative outcomes in patients who have lumbar foraminal or extraforaminal disc herniation (FELDH) and suggested the risk factors for poor outcomes. METHODS: A total of 234 patients were selected for this study. Pre- and post-operative Visual Analogue Scale (VAS) and Korean version Oswestry Disability Index (KODI) were evaluated and the changes of both score were calculated. Outcome was defined as excellent, good, fair, and poor based on Mcnab classification. The percentage of superior facetectomy was calculated by using the Maro-view 5.4 Picture Archiving Communication System (PACS). RESULTS: Paramedian lumbar discectomy was performed in 180 patients and combined lumbar discectomy was performed in 54 patients. Paramedian lumbar discectomy group showed better outcome compared with combined discectomy group. p value of VAS change was 0.009 and KODI was 0.013. The average percentage of superior facetectomy was 33% (range, 0-79%) and it showed negative correlation with VAS and KODI changes (Pearson coefficient : -0.446 and -0.498, respectively). Excellent or good outcome cases (Group I) were 136 (58.1%) and fair or poor outcome cases (Group II) were 98 (41.9%). The percentage of superior facetectomy was 26.5% at Group I and 42.5% at Group II. There was significant difference in superior facetectomy percentage between Group I and II (p=0.000). CONCLUSION: This study demonstrated that paramedian lumbar discectomy with preservation of facet joints is an effective and good procedure for FELDH. At least 60% of facet should be preserved for excellent or good outcomes.
Classification ; Diskectomy ; Humans ; Risk Factors* ; Zygapophyseal Joint