Thoracic kyphoscoliosis resembling neurofibromatosis: a case report focusing on subfascial instrumentation.

BACKGROUND CONTEXT: The management of early-onset progressive scoliosis is controversial. PURPOSE: To describe the unusual surgical management of a young female with an early-onset progressive, short, angular kyphoscoliosis resembling neurofibromatosis. STUDY DESIGN: A case report reviewing the treatment of an unusual occurrence of kyphoscoliosis. METHODS: After compliant Milwaukee brace wear had failed to stop deformity progression, surgical management including segmental anterior and posterior T5-T10 arthrodesis, and posterior T3-L4 subfascial rod instrumentation was performed at age 4 years and 6 months. After 10 rod lengthenings, segmental anterior T10 to L3 arthrodesis and posterior T3-L4 instrumentation and arthrodesis were done at age 11 years and 5 months. RESULTS: From preoperative to 3-year postoperative definitive surgery, her T3 to L4 instrumented spine length increased by 9.5 cm; 4 cm after the initial surgery, 3 cm between the initial surgery and the definitive surgery and 2.5 cm after the definitive surgery. From preoperative to latest follow-up, her thoracic scoliosis was reduced from 89 to 31 degrees, her thoracolumbar compensatory scoliosis from 59 to 37 degrees and her kyphosis from 70 to 17 degrees. CONCLUSIONS: The combination of early definitive anterior and posterior major curve arthrodesis with a subfascial rod lengthening program to control the remainder of the thoracolumbar spine was a satisfactory solution for this unusual case of early-onset, progressive, short, angular kyphoscoliosis.     

The surgical management of congenital kyphosis and kyphoscoliosis.

STUDY DESIGN: A retrospective study of surgery for congenital kyphosis and kyphoscoliosis. OBJECTIVE: To assess the effectiveness of different types of spine surgery in the management of congenital kyphosis and kyphoscoliosis. SUMMARY OF BACKGROUND DATA: Congenital kyphosis and kyphoscoliosis are much less common than congenital scoliosis but potentially more serious, because these curves can progress rapidly and Type I deformities can lead to spinal cord compression and paraplegia. No one operative procedure can be applied to all types and sizes of deformity. The method of surgical treatment depends on the age of the patient, the type and size of the deformity, and the presence or absence of spinal cord compression causing a neurologic deficit. METHODS: Sixty-five patients with a congenital kyphosis (n = 14) or kyphoscoliosis (n = 51) were treated by five different methods of spine arthrodesis: prophylactic posterior arthrodesis before age of 5 years (n = 11), posterior arthrodesis after age 5 years without instrumentation (n = 26) and with instrumentation (n = 12), combined anterior and posterior arthrodesis without instrumentation (n = 7) and with instrumentation (n = 9). Six patients had preoperative lower limb spastic paraparesis caused by spinal cord compression. The mean age at surgery was 9 years 6 months (range, 11 months to 25 years), and all 65 patients were observed for a minimum of 2 years (mean 6 years 6 months, range 2 to 18 years). Fifty-seven patients reached skeletal maturity. RESULTS: A posterior arthrodesis performed before the age of 5 years resulted in a gradual reduction of the kyphosis by a mean 15 degrees in 9 of the 11 patients, followed up for a mean of 11 years, whose initial kyphosis was less than 55 degrees. Patients treated after the age of 5 years by a posterior arthrodesis followed by cast application had poor correction and a high incidence of pseudarthrosis. This was not significantly improved by the addition of posterior instrumentation. For curves greater than 60 degrees, the most successful results were achieved by an anterior spinal release and arthrodesis with strut graft correction followed by posterior arthrodesis with instrumentation (if possible). CONCLUSION: All patients with a Type I or Type III congenital kyphosis or kyphoscoliosis should be treated by a posterior arthrodesis before the age of 5 years and before the kyphosis exceeds 50 degrees. A kyphosis that does not reduce to less than 50 degrees as measured on the lateral spine radiograph made with the patient supine requires an anterior release and arthrodesis with strut grafting followed by posterior arthrodesis with instrumentation (if possible).     

Simultaneous anterior-posterior approach through a costotransversectomy for the treatment of congenital kyphosis and acquired kyphoscoliotic deformities

BACKGROUND: Congenital kyphosis and acquired kyphoscoliotic deformities are uncommon but are potentially serious because of the risk of progressive deformity and possible paraplegia with growth. Our current approach for the treatment of these deformities is to use a single posterior incision and costotransversectomy to provide access for simultaneous anterior and posterior resection of a hemivertebra or spinal osteotomy, followed by anterior and/or posterior instrumentation and arthrodesis. To our knowledge, this approach has not been reported previously. METHODS: The medical records and radiographs for sixteen patients who had been managed at our institution for the treatment of congenital kyphosis and acquired kyphoscoliosis between 1988 and 2002 were analyzed. The mean age at the time of surgery was twelve years. The diagnosis was congenital kyphosis for fourteen patients and acquired kyphoscoliotic deformities following failed previous surgery for two. The mean preoperative kyphotic deformity was 65 degrees (range, 25 degrees to 160 degrees ), and the mean scoliotic deformity was 47 degrees (range, 7 degrees to 160 degrees ). Fifteen patients were managed with vertebral resection or osteotomy through a single posterior approach and costotransversectomy, anterior and posterior arthrodesis, and posterior segmental spinal instrumentation. The other patient was too small for spinal instrumentation at the time of vertebral resection. A simplified outcome score was created to evaluate the results. RESULTS: The mean duration of follow-up was 60.1 months. The mean correction of the major kyphotic deformity was 31 degrees (range, 0 degrees to 82 degrees ), and the mean correction of the major scoliotic deformity was 25 degrees (range, 0 degrees to 68 degrees ). Complications occurred in four patients; the complications included failure of posterior fixation requiring revision (one patient), lower extremity dysesthesias (one patient), and late progressive pelvic obliquity caudad to the fusion (two patients). The outcome, which was determined with use of a simplified outcomes score on the basis of patient satisfaction, was rated as satisfactory for thirteen patients, fair for two patients, and poor for one patient. CONCLUSIONS: A simultaneous anterior and posterior approach through a costotransversectomy is a challenging but safe, versatile, and effective approach for the treatment of complex kyphotic deformities of the thoracic spine, and it minimizes the risk of neurologic injury. LEVEL OF EVIDENCE: Therapeutic Level IV.     

Surgical treatment of congenital kyphosis

STUDY DESIGN: In this study, 26 cases of congenital kyphosis and kyphoscoliosis treated surgically were retrospectively reviewed. OBJECTIVE: To assess the clinical outcomes and surgical indications for posterior only versus anteroposterior surgery in the child. SUMMARY OF BACKGROUND DATA: Congenital kyphosis usually is progressive without surgical intervention. Current recommended treatment includes posterior arthrodesis for deformities of less than 50 degrees to 60 degrees, and anterior release or decompression, anterior fusion, and posterior instrumented arthrodesis for large deformities and cord compression. METHODS: Cases involving myelodysplasia, spinal dysgenesis, and skeletal dysplasia were excluded from the study. Kyphoscoliosis was included if the kyphotic deformity was greater than the scoliotic deformity. Patients were grouped by age and surgical technique. The patients in group P1 underwent posterior arthrodesis at an age younger than 3 years, and those in group P2 underwent the procedure at an age older than 3 years. The patients in group AP1 underwent anterior and posterior procedures at an age younger than 3 years, and those in group AP2 underwent the procedures at an age older than 3 years. The preoperative deformity, complications, and postoperative deformity correction were analyzed. There were nine Type 1 (failure of formation), nine Type 2 (failure of segmentation), and eight Type 3 (mixed) deformities. Four patients had associated spinal dysraphism. Three patients with Type 1 deformities had clinical or radiographic evidence of cord compression. RESULTS: In Group P1, five patients at an average age of 16 months underwent posterior arthrodesis alone for an average kyphotic deformity of 49 degrees. The immediate postoperative correction improved over a period of 6 years and 9 months by an additional 10 degrees, resulting in a final deformity of 26 degrees. Pseudarthrosis developed in two patients, requiring fusion mass augmentation or anterior arthrodesis. Neither patient was instrumented. In Group P2, five patients at an average age of 13 years and 7 months underwent posterior arthrodesis with instrumentation for kyphotic deformity of 59 degrees. Approximately 30 degrees of intraoperative correction was achieved safely using compression instrumentation and positioning. No further correction occurred with growth. The final residual kyphotic deformity was 29 degrees after a follow-up period of 4 years and 5 months. In Group AP1, seven patients underwent anterior release or vertebra resection for deformity correction and posterior arthrodesis for an average kyphotic deformity of 48 degrees at the age of 16 months. There were no iatrogenic neurologic injuries. The final residual kyphotic deformity was 22 degrees after a follow-up period of 6 years and 3 months. In Group AP2, nine patients underwent anterior release or decompression with posterior arthrodesis for kyphotic deformity of 77 degrees at the age of 11 years and 6 months. The deformity was corrected to 37 degrees, with no significant loss over a follow-up period of 5 years and 2 months. There were two postoperative neurologic complications. CONCLUSIONS: After reviewing their experience, the authors made the following observations: 1) The pseudarthrosis rate was low even without routine augmentation of fusion mass if instrumentation was used; 2) gradual correction of kyphosis may occur with growth in patients younger than 3 years with Types 2 and 3 deformities after posterior fusion, but appears to be unpredictable; 3) the risk of neurologic injury with anterior and posterior fusion for kyphotic deformity was associated with greater age, more severe deformity, and preexisting spinal cord compromise.     

Transforaminal Thoracic Interbody Fusion (TTIF) for Treatment of a Chronic Chance Injury

Multiple anterior and posterior approaches to the thoracic disc space have been reported. However, we are not aware of any previous reports describing a transforaminal approach for thoracic disc release and interbody cage placement. In this case report, we describe a method to perform transforaminal thoracic interbody fusion (TTIF), which is an adaptation of an established lumbar fusion technique (transforaminal lumbar interbody fusion). Key differences between the two procedures are discussed. A 24-year-old woman presented after sustaining a T11-12 Chance fracture that had been treated in a brace. She had severe, debilitating pain and a rigid segmental kyphotic deformity of 38°. The patient was treated 3 months post-injury with T10-L1 fusion with anterior release and interbody fusion with cage placement at T11-12. Anterior column release and fusion were performed via a transforaminal approach. The patient had anatomic reduction of deformity, solid arthrodesis, and relief of pain at 1-year follow-up. The TTIF approach permits access to the anterior column of the thoracic spine for the purpose of reduction of deformity and interbody fusion with reduced morbidity compared to anterior–posterior surgery.     

One-stage posterior hemivertebra resection and correction using segmental posterior instrumentation

STUDY DESIGN: A retrospective study of 12 patients with congenital kyphoscoliosis caused by a single hemivertebra who underwent one-stage posterior hemivertebra resection and correction by posterior segmental instrumentation. OBJECTIVES: To evaluate the surgical outcomes of 12 patients with hemivertebra treated by hemivertebra resection by single posterior approach and correction with segmental posterior instrumentation. SUMMARY OF BACKGROUND DATA: Congenital scoliosis caused by hemivertebra causes extremely severe curves in some patients. Posterior fusion or posterior and anterior hemi-epiphysiodesis is performed to prevent progression of the deformity. The results of these procedures have been variable and not promising, especially in an adolescent patient with fixed kyphoscoliotic deformity. Hemivertebra resection offers more certain results and better correction of the deformity. To date, hemivertebra resection is performed by anterior and posterior approaches either by one-stage or two-stage operation. Few reports have been published describing a procedure consisting of one-stage posterior hemivertebra resection and correction of the deformity by segmental posterior instrumentation. METHODS: A total of 12 patients with a single hemivertebra between the ages 8-24 years who underwent operative treatment were evaluated for a minimum of 2 years. All patients had a single nonincarcerated hemivertebra [T9 (1 patient), T10 (2), T11 (2), T12 (4), and L1 (3)]. After posterior hemivertebra resection, segmental posterior instrumentation was used for correction of the kyphoscoliotic deformity [CD (4 patients), Kaneda SR (2), and ISOLA (6)]. Radiographic evaluations were conducted on the preoperative, postoperative, and follow-up standing posteroanterior and lateral radiographs. RESULTS: All 12 patients had kyphoscoliotic deformity. Preoperative scoliosis averaging 49 degrees was corrected to 18 degrees (correction rate, 64%). Preoperative kyphosis of 40 degrees was corrected to 17 degrees of kyphosis. Trunk shift of 23 mm was improved to 3 mm. Correction loss was 2 degrees in the frontal plane and 3 degrees in the sagittal plane, and no patients showed more than 5 degrees of correction loss. No intraoperative complications were noted. Solid fusion was obtained in all patients, and no implant failure was verified at the final radiographic evaluations. CONCLUSIONS: This study indicated that correction of kyphoscoliosis caused by a single hemivertebra can be effectively conducted by one-stage posterior hemivertebra resection and correction using segmental posterior instrumentation. The operation was safe, and no associated adverse complications were noted. This procedure is best indicated for adolescent patients with a structural kyphoscoliotic deformity caused by a thoracic or thoracolumbar single hemivertebra.     

Use of a vascularized fibula for spinal reconstruction in neurofibromatosis

We report a case of reconstruction of a dysplasic thoracic spine with vascularized fibula in Recklinghausen's disease. We present the case of a thirteen-year-old lady with neurofibromatosis type 1 who developed a dystrophic thoracic kyphoscoliosis. A T9 compression due to a severe scaloping of the thoracic spine caused an important deformation and a medullar compression (with dorsal pain, right sciatica and a pyramidal syndrome). The surgery consisted in medullar liberation by a T9-T10 corporectomy and an osteosynthesis with arthrodesis T3-L3. A free vascularized fibula bone graft, with an end-to-end anastomosis on a thoracic pedicle, was realized to fill the T8-T11 spinal defect. All the symptoms decreased after surgery and the patient could walk normally few months later. At one-year follow-up the radiographs showed a stable montage and a solid bony fusion. Analysing the literature, vascularized bone graft can be recommended to fill the bony spinal defect due to surgery in cases of tumor, infection, trauma or severe scoliosis. Compared to non-vascularized grafts, which are exposed to resorption, fatigue fracture and then instability, the vascularized fibula grafts provide a rapid fusion, a biomechanically stable and long-standing support with low risks of infection.     

Single-staged double anterior and posterior spinal reconstruction for rigid adult spinal deformity: a report of four cases.

BACKGROUND CONTEXT: Sequential anterior/posterior spinal reconstruction for rigid adult spinal deformity has become a standard operative option. Single-staged double anterior/posterior spinal reconstruction for rigid double major curvature has not been reported in the literature to date. PURPOSE: To report a previously unreported approach for rigid double major curvature of the thoracic and thoracolumbar spine with emphasis on indications and avoiding complications. STUDY DESIGN: Four cases of sequential double anterior/posterior spinal reconstruction are reported. METHODS: Single-staged double anterior spinal reconstruction was performed on four adult patients with rigid thoracic and thoracolumbar scoliosis. Osteotomies were performed by the anterior and posterior approach and followed by posterior instrumentation. A right thoracotomy and left retropleural/retroperitoneal approach was performed for each patient followed by the posterior approach in a single stage. RESULTS: Only one complication occurred, a posterior dural tear, treated without incident. A high level of patient satisfaction and return to activity was noted. Solid arthrodesis with good coronal and sagittal balance occurred in all patients. CONCLUSIONS: Single-staged double anterior/posterior spinal reconstruction for rigid adult deformity can be performed safely and effectively with good patient outcome. The procedure should be reserved only for those patients with severe double major curvature of similar magnitude and rigidity.     

Cotrel-Dubousset instrumentation in neurofibromatosis spinal problems

Cotrel-Dubousset (CD) instrumentation has been employed in 12 patients with neurofibromatosis with spinal deformity (ten regular scoliosis, one dysplastic kyphoscoliosis, and one multilevel laminectomy). The follow-up period averaged 33 months. In regular scoliosis frontal correction averaged 69%, axial derotation averaged 33%, and sagittal normalcy was produced without immobilization and without pseudoarthrosis. Successful arthrodesis was obtained in a dysplastic patient after initial failure via anterior concave struts and posterior CD instrumentation with immobilization. Stabilization and fusion of one patient with multiple-level thoracic laminectomy was achieved without immobilization. CD instrumentation is effective in the surgical management of neurofibromatous spinal abnormalities.     

Surgical management of neurologically complicated kyphoscoliosis using transposition of the spinal cord: Case report

BackgroundTransposition of the spinal cord made it possible to achieve mobilization of the fixed kyphoscoliosis, significantly increase spinal canal volume and improve spinal canal shape. This helped to eliminate spinal cord compression and achieve complete regression of the existing neurological symptoms.Methods and resultsWe report the clinical case of surgical management of neurologically complicated kyphoscoliotic deformity of the thoracic spine by transposition of the spinal cord and correction using posterior segmental spinal instrumentation.ConclusionsThe required correction of severe kyphoscoliosis was performed; the risks of trunk imbalance, deformity progression, and instrumentation failure in the long-term postoperative period were reduced.Level of evidenceLevel IV – 1 case.     

Posterior Vertebral Column Resection for VATER/VACTERL Associated Spinal Deformity: A Case Report

The VATER/VACTERL association is a syndrome notable for congenital vertebral malformations, anal atresia, cardiovascular anomalies, tracheoesophageal fistula, esophageal atresia, and renal or limb malformations. Vertebral malformations may include the entire spectrum of congenital spinal deformities, including kyphosis, as was seen in this case. A 14-year-old girl presented to our institution with severe rigid sagittal deformity in the thoracolumbar spine that had recurred following three prior spinal fusion surgeries: the first posterior only, the second anterior and posterior, and the third a posterior only proximal extension. These surgeries were performed to control progressive kyphosis from a complex failure of segmentation that resulted in a 66° kyphosis from T11 to L3 by the time she was 9 years old. Our evaluation revealed solid arthrodesis from the most recent procedures with resultant sagittal imbalance, and surgical options to restore balance included anterior and posterior revision spinal fusion with osteotomies, multiple posterior extension osteotomies with circumferential spine fusion, and posterior vertebral column resection with circumferential spine fusion. She was advised that multiple posterior extension osteotomies would likely be insufficient to restore sagittal balance in the setting of solid arthrodesis from anterior and posterior surgery, and that the posterior-only vertebral column resection would provide results equivalent to revision anterior and posterior surgery, without the morbidity of the anterior approach. She successfully underwent posterior vertebrectomy and circumferential spinal fusion with instrumentation and is doing well 2 years postoperatively. Severe rigid sagittal deformity can be effectively managed with a posterior-only surgical approach, vertebrectomy, and circumferential spinal fusion with instrumentation. An erratum to this article can be found at     

Scoliosis surgery in neurofibromatosis

Twenty-three patients who were treated by posterior spinal fusion with neurofibromatous scoliosis were reviewed to study the adequacy of spinal fusion, rate of pseudarthrosis, and incidence of complications. Twenty patients achieved a solid fusion with posterior surgery alone. Thirteen patients required one or more posterior augmentation procedures because of progressive deformity. Three patients with dystrophic kyphoscoliosis required an anterior spinal fusion in addition to the posterior fusion to achieve a solid fusion mass. The type of graft material, Harrington instrumentation, and degree of kyphosis or scoliosis had no effect on the rate of pseudarthrosis. Preoperative neuroradiographic evaluation was found to be warranted for all patients with neurofibromatous scoliosis.     

Double-segment total vertebrectomy for the surgical treatment of congenital kyphoscoliosis: a case report

BACKGROUND CONTEXT: Congenital kyphosis or kyphoscoliosis is an uncommon deformity that usually is progressive without surgical intervention. In the lately diagnosed or neglected cases of congenital kyphoscoliosis, the patients may come with shoulder-trunk imbalance anomalies, severe deformity in coronal and sagittal plane, rib cage deformities, pelvic tilt, presence of intramedullary anomalies, neurological deficit, and difficulty in walking and cardiopulmonary problems. PURPOSE: To present a technical note related with double-segment total vertebrectomy for the surgical treatment of a patient who had neglected congenital kyphoscoliosis in lumbar spine. STUDY DESIGN: Case report. METHODS: A 19-year-old girl had submitted to our center with complaints of deformity and pain in her back. Her physical examination revealed scoliosis and gibbosity in lumbar region. Her neurological examination was normal. In the radiological examination, X-ray films showed 42 degrees lumbar scoliosis in frontal plane and 35 degrees kyphotic curvature in the sagittal plane. RESULTS: Three-staged (posterior-anterior-posterior) surgery in the same session (same anesthesia) was performed. CONCLUSION: Total or partial vertebrectomy on the apex of the deformity and the adjacent vertebral bodies along with anterior stabilization by means of a cylindrical cage combined in one operative procedure preceded by temporary posterior instrumentation and followed by posterior instrumentation and fusion may be preferred for the treatment of congenital kyphoscoliosis in neglected cases to provide spinal cord decompression.     

Surgical treatment of Scheuermann's disease with segmental compression instrumentation

Twenty-one patients with Scheuermann's kyphosis had surgery for progressive kyphotic deformity of 50 degrees or greater. There were six adolescents, with a mean age of 15.6 years (range, 13-17 years) and 15 young adults, with a mean age of 25.4 years (range, 18-40 years). All patients had posterior spine arthrodesis with segmental compression instrumentation. Seven patients with rigid kyphosis had combined anterior and posterior spine arthrodesis. One patient died of superior mesenteric artery syndrome. In the group of 13 patients with posterior arthrodesis only, followup was 4.5 years. The mean preoperative thoracic kyphotic curve of 68.5 degrees improved to 40 degrees at latest review, with an average loss of correction of 5.75 degrees. Junctional kyphosis occurred in two patients with a short arthrodesis: one at the cephalad end and one at the caudal end of the fused kyphotic curve. In the second group of seven patients with combined anterior and posterior arthrodesis, followup was 6 years. The mean preoperative thoracic kyphotic curve of 86.3 degrees improved to 46.4 degrees at latest review, with an average loss of correction of 4.4 degrees. Overall, there was no postoperative neurologic deficit and no pseudarthrosis. Thus, posterior arthrodesis and segmental compression instrumentation seems to be effective for correcting and stabilizing kyphotic deformity in Scheuermann's disease. Despite a long operating time, this technique provided significant correction, avoiding the development of any secondary deformity in most patients. Combined anterior and posterior spine arthrodesis is recommended for rigid, more severe kyphotic deformities.     

Late post-operative paraparesis after rib penetration of the spinal canal in a patient with neurofibromatous scoliosis

Rib displacement into the spinal canal is a rare cause of paraplegia or paraparesis in patients affected by neurofibromatous scoliosis. We describe a case of paraparesis in a 14-year-old child affected by neurofibromatous dystrophic kyphoscoliosis, treated with combined posterior and anterior spinal arthrodesis. Seventeen days after the surgical treatment the patient developed clinical signs and symptoms of paraparesis. A CT scan showed the head of the fifth rib protruding into the spinal canal with cord compression. Rib resection and posterior cord decompression were carried out following complete neurological recovery.     

Closing-opening wedge osteotomy to correct angular kyphotic deformity by a single posterior approach

STUDY DESIGN: Seven patients with angular kyphotic deformity of the thoracic or thoracolumbar spine were treated by closing-opening wedge osteotomy using a single posterior approach. OBJECTIVES: To examine the safety and efficacy of closing-opening wedge osteotomy for angular kyphosis. SUMMARY OF BACKGROUND DATA: Correction osteotomy of severe kyphosis is a challenging operation. A two-stage operation has been commonly used: anterior release and decompression followed by posterior correction and fusion. METHODS: Seven patients with angular kyphosis were treated. The apex level of kyphosis was T5 in one patient, T11 in one, and T12 in five. There was old fracture in five patients, congenital deformity in one, and neurofibromatosis in one. The first 30-35 degrees of kyphosis are corrected using the closing wedge technique with the hinge of the anterior longitudinal ligament after veretebrectomy and circumspinal decompression of the spinal cord. Then the hinge is moved posteriorly to the spinal cord and the remainder of the requisit angle of osteotomy is corrected using the opening-wedge technique (closing-opening wedge osteotomy). Spinal curvature is stabilized using posterior instrumentation and graft. RESULTS: Localized kyphosis was reduced from an average of 67 degrees to 18 degrees at 2.2 to 7.5 years' follow-up. Sagittal alignment from T1 to the sacrum became more physiologic than before. There were no neurologic complications. Bony fusion was achieved in all patients, and there was no correction loss. CONCLUSIONS: Satisfactory correction is safely performed by closing-opening wedge osteotomy with a direct visualization of the circumferentially decompressed spinal cord. Although the performance is technically laborious, it offers good correction without jeopardizing the integrity of the spinal cord.     

Techniques of anterior spinal surgery for the management of kyphosis.

Experience with the techniques of spinal surgery for the management of thoracic and lumbar kyphosis suggests that the anterior approach is useful for correcting fixed deformity (achieving solid arthrodesis and decompressing the spinal cord when necessary). The insertion of an anterior bone graft alone does not guarantee a solid arthrodesis. Meticulous technique, autologous bone, and efficient immobilization are essential for a satisfactory result.     

Spine deformity in neurofibromatosis. A review of one hundred and two patients.

The natural history, associated anomalies, and response to operative and nonoperative treatment were reviewed in 102 patients with neurofibromatosis and spine deformity. Eighty patients were found to have curvatures associated with dystrophic changes in the vertebrae and ribs. The presence of dystrophic changes such as rib penciling, spindling of the transverse processes, vertebral scalloping, severe apical vertebral rotation, foraminal enlargement, and adjacent soft-tissue neurofibromas was found to be highly significant in prognosis and management. Brace treatment of dystrophic curves was unsuccessful. Posterior fusion, with or without internal fixation, was the procedure of choice for problems due purely to scoliosis. Patients with dystrophic kyphoscoliosis required both anterior and posterior fusion to achieve stability. Sixteen patients had compression of the spinal cord or cauda equina.     

A comparative biomechanical analysis of spinal instability and instrumentation of the cervicothoracic junction: an in vitro human cadaveric model

OBJECTIVE: Stabilization of the cervicothoracic junction is challenging but commonly required in patients with traumatic, neoplastic, congenital, and postlaminectomy conditions. Although extensive research has been performed on stabilization of the cervical spine, there remains a paucity of published data on instrumentation at the cervicothoracic junction. Using 2-column, 3-column, and corpectomy instability models, a biomechanical analysis was performed on the effects of increasing the number of posterior segmental fixation points and/or anterior column reconstruction at the cervicothoracic junction. METHODS: Multidirectional flexibility testing was performed utilizing a 6-degree-of-freedom spine simulator and 7 fresh-frozen human cadaveric spines (occiput-T6). After intact spine analysis, each specimen was destabilized and reconstructed as follows: (1) C7/T1 2-column injury with posterior instrumentation; (2) C7/T1 3-column injury with posterior instrumentation; (3) C7/T1 3-column injury with anterior interbody cage/plate and posterior instrumentation; and (4) C7/T1 3-column injury plus C7 corpectomy with anterior cage/plate and posterior instrumentation. All reconstruction groups were tested with posterior instrumentation (screws connected by dual-diameter rods) from C5-T1, C5-T2, and C5-T3. RESULTS: For 2-column injuries, there were no statistically significant differences in flexibility (P>0.05), although there was a trend toward reduced flexibility with increasing levels of thoracic fixation. For 3-column injuries, posterior fixation alone resulted in excessive flexibility in flexion/extension even with instrumentation to T3 (P<0.05). With the addition of anterior column instrumentation, there were no observed differences in flexion/extension and lateral bending. For axial rotation, instrumentation to T1 alone demonstrated increased motion relative to the intact spine (P<0.05). The 3-column injury with corpectomy model demonstrated similar flexibility properties to the 3-column injury model. CONCLUSIONS: With 3-column instability posterior segmental fixation alone from C5-T3 was inadequate, and the addition of anterior instrumentation restored flexibility to the intact condition. There was a strong trend toward reduced flexibility with increasing levels of thoracic fixation in all instability models.     

Progressive rotational dislocation in kyphoscoliotic deformities: presentation and treatment

STUDY DESIGN: Progressive rotational dislocation of the spine has been described as the most serious evolutive risk of kyphoscoliosis. A retrospective chart review was conducted on 11 patients with this deformity. OBJECTIVES: To delineate the clinical and radiologic characteristics of this entity to facilitate early diagnosis and treatment. The outcome after treatment was analyzed to point out the rationale for appropriate treatment. METHODS: The characteristic radiologic feature was a short sharp angled kyphosis (average 112) at the junction of two lordoscoliotic curvatures. The etiology of the spinal deformity was neurofibromatosis in four patients and various dysplastic conditions in seven patients. Two patients had congenital vertebral defects. Structural weakness of the bone was therefore a basic feature. Neurologic impairment was identified in three patients (one complete, two incomplete). Four patients had a nonunion after a previous attempt at spinal fusion: two after a combined anterior and posterior fusion with an anterior approach from the convexity and two after a posterior fusion alone. All patients underwent complete circumferential stabilization through anterior strut-grafting and posterior fusion. An anterior approach from the concavity was performed systematically with tibial strut grafts inserted in a palisade fashion. Preoperative correction of the deformity was performed by progressive controlled elongation in a Stagnara elongation cast. Cotrel-Dubousset instrumentation was used in two patients, Harrington instrumentation was used in two patients, and cast immobilization alone was used in seven patients. RESULTS: The average follow-up period was 5 years 5 months. All but one patient achieved successful spinal fusion. Loss of correction at the latest follow-up evaluation was less than 3 degrees in nine patients. The two patients with incomplete neurologic deficits were improved, but the patient with the complete deficit remained unchanged after surgery. CONCLUSIONS: Awareness of the possibility of a progressive rotational dislocation in dystrophic forms of kyphoscoliosis should allow for an early diagnosis and stabilization. The percentage of patients having a neurologic deficit in this series was significantly less important than in the initial report. Early anterior strut grafting from the concavity of the scoliotic curvature and posterior fusion is recommended.