Significance of angular mismatch between vertebral endplate and prosthetic endplate in lumbar total disc replacement.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine whether angular mismatch between the vertebral endplate and prosthetic endplate during lumbar total disc replacement (L-TDR) affects the radiological and clinical outcomes. SUMMARY OF BACKGROUND DATA: A prosthesis anchored to the vertebral body by using a large central keel carries an inherent risk of angular mismatch between the vertebral endplate and prosthetic endplate at a segment with a greater degree of lordosis, such as L5-S1. Theoretically, this angular mismatch can cause several problems, such as segmental hyperlordosis, anterior positioning of the upper prosthesis, posterior prosthetic edge subsidence, decreased range of motion (ROM), and a poor clinical outcome. METHODS: This study evaluated 64 prosthetic levels of 56 patients who were implanted with L-TDR between June 2002 and February 2006. There were 38 and 26 prosthetic levels at the L4-5 and L5-S1, respectively. The mean follow-up period was 25.6 (12 to 49) months. The angle of mismatch between the lower endplate of the upper vertebral body and the upper prosthetic plate, segmental flexion/extension ROM, segmental lordosis angle at extension, distance from the posterior wall of the vertebral body to the posterior prosthetic edge were measured by obtaining radiographs. Clinically, the Visual Analogue Scale and Oswestry Disability Index were also evaluated. RESULTS: The angular mismatches between the upper vertebra and prosthesis at L4-5 and L5-S1 were 1.6 degree and 5.6 degree, respectively (P <0.001), at the final follow-up; these angles were not significantly different from those measured on radiographs obtained postoperatively (2.3 degree and 4.9 degree in L4-5 and L5-S1, respectively, P=0.324 in L4-5 and P=0.620 in L5-S1). The mean segmental ROM of the operated levels was 10.6 degree (4 to 22) and 6.1 degree (2 to 13) in the L4-5 and L5-S1, respectively (P <0.001). The mean segmental ROM, mean segmental lordosis angle, and mean distance from the posterior margin of the vertebral body to the posterior edge of the prosthesis in L5-S1 were 6.8 degree (4 to 13), 12.8 degree (8 to 17), and 3.8 mm (1 to 6 mm) in patients with an angular mismatch of <10 degree, and were 4.6 degree (2 to 7), 21.3 degree (19 to 25), and 6.0 mm (2 to 8 mm) in patients with an angular mismatch of more than 10 degree (P=0.024, <0.001, and 0.039), respectively. In L4-5, there were only 2 cases with an angular mismatch of more than 5 degree, which had no statistical significance. There were no significant differences in the clinical outcomes, Visual Analogue Scale, and Oswestry Disability Index between patients with an angular mismatch of <10 degree and those with an angular mismatch of more than 10 degree (P >0.05). CONCLUSIONS: Angular mismatch was more common in L5-S1 than in L4-5. L-TDR at the most lordotic level, L5-S1, and implantation of an upper prosthesis with a mismatched angle seem to be the causes of a reduced segmental ROM, increased segmental lordosis, and anterior malpositioning of the prosthesis. However, these changes do not affect the clinical outcomes of patients.

Results of Decompression Alone in Patients with Lumbar Spinal Stenosis and Degenerative Spondylolisthesis: A Minimum 5-Year Follow-up.

BACKGROUND: Surgical treatment consisting of decompression and fusion is generally known to produce good clinical results for lumbar spinal stenosis with degenerative spondylolisthesis. However, the clinical outcome of decompression alone, without fusion, remains unclear, and long-term follow-up results are scarce. This study aimed to retrospectively analyze the 5-year clinical results of decompression only in patients with lumbar spinal stenosis and degenerative spondylolisthesis. METHODS: Among the patients diagnosed as having lumbar spinal stenosis with degenerative spondylolisthesis, 36 patients who underwent decompression without fusion and were followed up for minimum 5 years were included in this study. The average follow-up period was 7.2 years, and the mean age of patients was 63.2 years. Visual analog scale (VAS) score and Oswestry disability index (ODI) were investigated pre- and postoperatively, and also radiologic displacement and instability were measured. In addition, patients who needed fusion or redecompression at the decompression site postoperatively were also investigated. RESULTS: VAS score and ODI improved from an average of 7.8 points and 57 points preoperatively, respectively, to 1.4 points and 19 points at 5 years postoperatively, respectively. The degree of radiologic displacement increased from an average of 5.1 mm preoperatively to 6.4 mm at the final follow-up. Radiological instability was detected in five patients. Two patients (9.5%) required fusion. CONCLUSIONS: The long-term follow-up results revealed that satisfactory clinical outcomes were obtained with decompression alone, without fusion, for patients with lumbar spinal stenosis and degenerative spondylolisthesis.

Arthroscopic versus mini-open salvage repair of the rotator cuff tear: outcome analysis at 2 to 6 years' follow-up.

PURPOSE: The purpose of this study was to compare the outcomes of arthroscopic repair of medium and large rotator cuff tears with the outcomes for mini-open repair of similar tears in which arthroscopic repair was technically unsuccessful. TYPE OF STUDY: Retrospective case series. METHODS: We evaluated 76 patients who were treated for full-thickness rotator cuff tears either by all-arthroscopic (42 patients) or mini-open salvage of technically unsuccessful arthroscopic repair (34 patients). Patients who had acromioclavicular arthritis, subscapularis tear, or instability were excluded. There were 39 men and 37 women, with a mean age of 56 years (range, 42 to 75 years). At a mean follow-up of 39 months (range, 24 to 64 months), the results of both groups were compared using the University of California Los Angeles and American Shoulder and Elbow Surgeons shoulder rating scales. RESULTS: Shoulder scores improved in all ratings in both groups (P <.05). Overall, 66 patients showed excellent or good and 10 patients showed fair or poor scores by the University of California Los Angeles scale. Seventy-two patients satisfactorily returned to previous activity, and 4 showed unsatisfactory returns. The range of motion, strength, and patient satisfaction were improved postoperatively. No differences were seen in shoulder scores, pain, and activity return between the arthroscopic and mini-open salvage groups (P >.05). However, patients with larger tears showed lower shoulder scores and less predictable recovery of strength and function (P <.05). Postoperative pain was not different with respect to the size of the tear (P =.251). CONCLUSIONS: Arthroscopic repair of medium and large full-thickness rotator cuff tears had an equal outcome to technically unsuccessful arthroscopic repairs, which were salvaged by conversion to a mini-open repair technique. Surgical outcome depended on the size of the tear, rather than the method of repair.

Intradural extramedullary tuberculoma mimicking en plaque meningioma.

A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy.

Correlation of pelvic parameters with isthmic spondylolisthesis.

STUDY DESIGN: A retrospective radiological evaluation. PURPOSE: To verify that PI is related with progression of IS as well as development of IS and to assess the differences of pelvic parameters between the L4 & L5 IS, as well as between single & two level IS. OVERVIEW OF LITERATURE: High pelvic incidence (PI) has been known to be related with development of IS. However, the previous studies were limited to just L5 spondylolisthesis or there was no differentiation between L4 & L5 spondylolisthesis METHODS: Sixty five IS patients and 30 persons as a control group participated the study. Among the 65 patients, 30 had L4 IS, 30 had L5 IS and 5 had bi-level IS. We used the whole spine lateral radiographs to measure the slip percentage, the pelvic tilt (PT) and the pelvic incidence (PI), and we compared them between the normal control group and the IS patients, as well as between single-level and bi-level spondylolisthesis, and we investigated the correlation between the degree of slip of spondylolisthesis and the pelvic parameters. RESULTS: The averages of the PT, PI and lumbar lordosis (LL) in the control group and the IS group were 11.0 degrees vs 21.4 degrees (p<0.001), 49.1 degrees vs 61.8 degrees (p<0.001) and 48.5 degrees vs 57.6 degrees (p<0.001), respectively. On comparison between the L4 and L5 IS groups, there was no difference in all the pelvic parameters (p>0.05). On comparison between the single-level IS group and the bilevel IS group, there was a significant difference of the PT and PI (p<0.05), and the slip percentage had a correlation with only the PI among all the pelvic parameters (Spearman's r=0.293, p=0.023). There was a significant correlation of the degree of slip with the PI for the L5 single level IS, but not with the L4 single level IS (r=0.362, p=0.05). CONCLUSIONS: The high pelvic incidence can be a factor of L4 & L5 spondylolysis and it may have an influence on the slip progression in patients with L5 isthmic spondylolisthesis, but not on the slip progression in patients with L4 IS. Yet other factors seem to have an influence on the slip progression in patients with L4 isthmic spondylolisthesis.

Congenital absence of unilateral lumbar articular process - a case report -.

A congenital absence of a lumbar articular process is a rare condition with an uncertain etiology. However, an intervertebral instability caused by this anomaly can cause occasional lower back pain. A 20 years old man presented with lower back pain. The physical examination revealed no neurological deficits. Plain radiographs of the lumbar spine revealed an absence of the left inferior articular process at the fourth lumbar vertebra associated with hypoplasia of the left lamina. The patient's symptoms were resolved after conservative treatment. We report a case of a congenital absence of articular process at the fourth lumbar vertebra.

The effects of intersegmental compression on the 3-d correction of idiopathic scoliosis using thoracoscopic surgery.

STUDY DESIGN: Retrospective study. PURPOSE: To investigate whether intersegmental compression can affect the results of threedimensional correction for idiopathic scoliosis. OVERVIEW OF LITERATURE: Intersegmental compression is usually performed to increase the correction rate and enhance kyphosis restoration. However, it is presumed that the risk of decompensation is increased. METHODS: Twenty-seven patients with idiopathic scoliosis who were corrected thoracoscopically were divided into two groups: a compression group and a non-compression group. Thoracic and lumbar scoliotic Cobb angles were measured pre-operatively, one week postoperatively, and at last follow-up. Changes in thoracic kyphosis and in sagittal and coronal balance were compared. RESULTS: The average correction rates for thoracic scoliotic curves were 70.3% and 58.8% in the compression and non-compression groups, respectively (p=0.023), at 1 week postoperatively. However, these changed to 62.6% and 58.1% at the final follow-up visit (p=0.381). Thoracic kyphosis increased by 37.4% in the compression group and 20.9% in the non-compression group at 1 week postoperatively (p=0.435). Finally, thoracic kyphosis increased by 59.9% and 42.6%(p=0.473), respectively, at final follow-up. Axial rotation was corrected by 45.3% and 24.7% in the compression and non-compression groups, respectively (p=0.214). There were no significant differences in postoperative changes in coronal and sagittal balance between the two groups. CONCLUSIONS: Three-dimensional correction by intersegmental compression tended to produce better results, especially during the early postoperative period. However, at final follow-up, no significant differences were observed between the two groups in terms of three-dimensional correction. Thus, we conclude that intersegmental compression is not always necessary for thoracoscopic scoliosis correction.