P450RAI (CYP26A1) maps to human chromosome 10q23-q24 and mouse chromosome 19C2-3

STUDY DESIGN: A case report. OBJECTIVES: To document a fracture of the 11th thoracic vertebra after spine fusion for adult idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Three cases of vertebral fractures associated with spine fusion for scoliosis were found in the literature. METHODS: Medical and radiologic records and related literature were reviewed. RESULTS: A 30-year-old woman had undergone anterior and posterior fusion with Cotrel-Dubousset instrumentation for progressive idiopathic scoliosis. Two years after surgery, she was in a car accident. A radiographic study and computer tomographic scanning depicted a fracture of T11 and bending of the rods. Observation was instituted and symptoms resolved. CONCLUSIONS: Fracture of a vertebra within an extensive spine fusion for scoliosis is rare. The 360 degrees solid fusion together with strong posterior instrumentation may have had some protective effect in this patient.     

Spinal problems in mucopolysaccharidosis I (Hurler syndrome)

Bone-marrow transplantation has increased the survival of patients with mucopolysaccharidosis-I. We describe the spinal problems and their management in 12 patients with this disorder who have been followed up for a mean of 4.5 years since transplantation. High lumbar kyphosis was seen in ten patients which was associated with thoracic scoliosis in one. Isolated thoracic scoliosis was seen in another. One patient did not have any significant problems in the thoracic or lumbar spine but had odontoid hypoplasia, which was also seen in three other children. Four of the eight patients in whom MRI of the cervical spine had been performed had abnormal soft tissue around the tip of the odontoid. Neurological problems were seen in two patients. In one it was caused by cord compression in the lower dorsal spine 9.5 years after posterior spinal fusion for progressive kyphosis, and in the other by angular kyphosis with thecal indentation in the high thoracic spine associated with symptoms of spinal claudication.     

24-h blood pressure and autonomic function is related to albumin excretion within the normoalbuminuric range in IDDM patients

A retrospective review was performed to determine "crankshaft" prevalence in 86 immature patients who underwent posterior spinal fusion for idiopathic scoliosis. Tanner stage, chronologic age, bone age, and epiphyseal status were used as maturity indicators. Overall, 62 (72%) patients progressed < or = 10 degrees, 18 (21%) patients progressed 11-15 degrees, and six (7%) patients progressed > or = 16 degrees in the coronal plane. Tanner I patients with open triradiate cartilage had the highest rate of crankshaft occurrence; nine (75%) of 12 patients progressed >10 degrees (p < 0.05). Fifty-two percent of Tanner I, 26% of Tanner II, 11% of Tanner III, and no Tanner IV patients progressed >10 degrees (p < 0.05). Cobb angle increases of >10 degrees degrees occurred in 54% of patients with open triradiate cartilage (p < 0.05) and in 48% of patients with open capital femoral epiphyses (p < 0.05). Anterior and posterior spinal fusion should be considered in prepubertal (Tanner I) patients with open triradiate cartilage.     

The long-term follow-up of patients with Klippel-Feil syndrome and congenital scoliosis

STUDY DESIGN: This study evaluated the long-term results of Klippel-Feil syndrome in patients with congenital scoliosis. OBJECTIVES: To determine the incidence of cervical and cervical-related symptoms of patients who have Klippel-Feil syndrome associated with congenital scoliosis. SUMMARY OF BACKGROUND DATA: Many authors have described the association of Klippel-Feil syndrome and congenital scoliosis. In this population of patients, cervical lesions often are discovered incidentally. The significance of these lesions is unknown. METHODS: Thirty-two patients with congenital scoliosis and Klippel-Feil syndrome were observed for more than 10 years. They were questioned specifically about cervical and cervical-related symptoms. All patients had sequential cervical radiographs and physical examinations. RESULTS: Despite rather dramatic radiographic appearances, only seven (22%) of the 32 patients had cervical or cervical-related symptoms, with two patients requiring surgery for their cervical lesions. The extent of the deformities and the average number of cervical vertebrae fused and cervical fusion-patterns were statistically similar between the symptomatic and asymptomatic groups. Patients fused to the cervicothoracic junction for management of their deformities had a significantly increased incidence of cervical symptoms. Also, patients with congenital stenosis had a significantly greater incidence of upper extremity pain. CONCLUSIONS: Only a small number of patients with Klippel-Feil syndrome and congenital scoliosis developed cervical symptoms. No fusion pattern that placed the patient at greater risk for developing symptoms could be identified. Factors that did lead to a greater incidence of cervical symptoms were fusion to the cervicothoracic junction and congenital cervical stenosis.     

1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation

STUDY DESIGN: This prospective study analyzed the influence of transpedicular instrumented on the operative treatment of patients with degenerative spondylolisthesis and spinal stenosis. OBJECTIVES: To determine whether the addition of transpedicular instrumented improves the clinical outcome and fusion rate of patients undergoing posterolateral fusion after decompression for spinal stenosis with concomitant degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Decompression is often necessary in the treatment of symptomatic patients who have degenerative spondylolisthesis and spinal stenosis. Results of recent studies demonstrated that outcomes are significantly improved if posterolateral arthrodesis is performed at the listhesed level. A meta-analysis of the literature concluded that adjunctive spinal instrumentation for this procedure can enhance the fusion rate, although the effect on clinical outcome remains uncertain. METHODS: Seventy-six patients who had symptomatic spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied. All patients underwent posterior decompression with concomitant posterolateral intertransverse process arthrodesis. The patients were randomized to a segmental transpedicular instrumented or noninstrumented group. RESULTS: Sixty-seven patients were available for a 2-year follow-up. Clinical outcome was excellent or good in 76% of the patients in whom instrumentation was placed and in 85% of those in whom no instrumentation was placed (P = 0.45). Successful arthrodesis occurred in 82% of the instrumented cases versus 45% of the noninstrumented cases (P = 0.0015). Overall, successful fusion did not influence patient outcome (P = 0.435). CONCLUSIONS: In patients undergoing single-level posterolateral fusion for degenerative spondylolisthesis with spinal stenosis, the use of pedicle screws may lead to a higher fusion rate, but clinical outcome shows no improvement in pain in the back and lower limbs.     

Delayed postoperative paraparesis in scoliosis surgery. A case report

STUDY DESIGN: A case report is presented of an unusual complication of scoliosis surgery that, to the authors' knowledge, has never been reported in the literature. OBJECTIVE: Neurologic complications can occur after an uneventful posterior spinal instrumentation and fusion for scoliosis. Careful observation during the post-operative period is crucial for early detection of impending neurologic deficit. SUMMARY OF BACKGROUND DATA: Nerve compression of the cauda equina has been reported as a complication of different types of surgery in the lumbar spine, but an ascending paraparesis has never been described as a complication of scoliosis surgery. METHODS: A 12-year-old boy with a right thoracic scoliosis measuring 68 degrees and a 72 degrees left lumbar curve underwent Cotrel-Dubousset instrumentation and fusion from T5 to L4. Spinal cord monitoring with somatosensory evoked potentials and motor action potential were recorded and stable through out the entire procedure. Thirty hours later, a rapidly progressive ascending para-paresis developed that required urgent decompression. RESULTS: This patient underwent urgent decompression and removal of the Cotrel-Dubousset instrumentation. After surgery, the clinical picture improved gradually, and at 2-month follow-up he had regained normal strength in his lower limbs except for a grade 4 left extensor hallucis longus. By 4 months postdecompression, he had made a total recovery. CONCLUSIONS: Although clinical examination may be difficult to perform in patients who are unconscious, on large doses of narcotic drugs, or mentally retarded, careful observation during the postoperative period and awareness of this complication can allow early detection of impending reversible neurologic deficit and provision of appropriate treatment.     

Long-term evaluation of single crystal sapphire implants as abutments in fixed prosthodontics

STUDY DESIGN: This retrospective study evaluated the progression of deformity after posterior fusion by reviewing 63 consecutive patients with idiopathic scoliosis who were all in Risser sign 0 at the time of surgery. All patients were observed beyond the time of skeletal maturity. Average follow-up time was 9 years and 8 months (range, 5-16 years). OBJECTIVES: To investigate the risk factors for the crankshaft phenomenon after posterior fusion and to build a model for predicting the probability of curve progression until maturation of growth. SUMMARY OF BACKGROUND DATA: There remains considerable controversy concerning the incidence, risk factors, and necessity of combined anterior fusion to prevent the crankshaft phenomenon in patients who are skeletally immature. METHODS: Serial radiographs were measured for Cobb angle, apical rotation according to Perdriolle, and apical rib-vertebra angle of Mehta. Multivariate and univariate logistic regression analysis was performed using seven potential predictors as independent variables and Cobb angle progression and rotational progression as dependent variables. RESULTS: Average progression of deformity was 3 degrees Cobb angle (range, -8-16 degrees) and 3 degrees Perdriolle rotation (range, -9-17 degrees). Progression of deformity more than 5 degrees of either Cobb angle or rotation was observed in 22 (35%) of 63 curves with 7 (11%) of 63 curves greater than 10 degrees. Chronologic age and skeletal age were found to be significantly associated with progression of deformity in univariate analysis. In multivariate analysis, only skeletal age seemed to be independently prognostic. The authors tried to build the logistic model using the three factors of chronologic age, skeletal age, and apical rib-vertebra angle. This model correctly classified 81% of all patients as progressive or nonprogressive. The positive predictive value was 90%. CONCLUSIONS: The results showed that patients with chronologic age of 11 years of younger, especially those with a skeletal age of 10 years or younger, had a high estimated probability of progression of deformity. The progression was fairly moderate, however, with an average Cobb angle of 9 degrees and average rotation of 7 degrees, which neither the patients nor the surgeon believed was of such magnitude as to warrant routine combined anterior fusion.     

Results and morbidity in a consecutive series of patients undergoing spinal fusion for neuromuscular scoliosis

STUDY DESIGN: A retrospective clinical and radiographic review. OBJECTIVES: To provide current data on the results and complications of patients who have undergone spinal fusion for neuromuscular scoliosis at a center with physicians experienced in these types of cases. SUMMARY OF BACKGROUND DATA: The reported complication rate in the management of neuromuscular scoliosis ranges from 44% to 62% in the recent literature. This literature is that of 1991 or earlier reflecting operative techniques of the mid-1980s, and it has been used to argue against the efficacy of neuromuscular spinal fusions. METHODS: A retrospective chart and radiographic review of 50 consecutive spinal fusions for neuromuscular scoliosis was performed at Connecticut Children's Medical Center between January 1990 and January 1994. The three most common diagnoses were spastic quadriplegic cerebral palsy (20 patients), myelomeningocele (13 patients), and muscle disease (8 patients). There were 38 posterior spinal fusions including two kyphectomies and 12 anteroposterior spinal fusions. The Luque-Galveston technique was used in 39 of 50 patients. The average age at surgery was 13 years and 6 months, with an average follow-up of 40 months (minimum, 24 months). RESULTS: Before surgery, the mean major scoliosis measured 72 degrees, with mean best bend or traction view of 35 degrees. At most recent follow-up, the mean scoliosis magnitude was 25 degrees (mean correction, 65%). There were 17 minor complications in 14 patients and three major complications (deep wound infections) in three myelomeningocele patients. Rod breakage was noted in two patients, one of whom had an asymptomatic pseudarthrosis. There were no neurologic complications or deaths, and none of the complications affected the final results. CONCLUSIONS: The data in the current study support the authors' belief that with current surgical techniques and perioperative management in an experienced center, the results for patients undergoing spinal fusion for neuromuscular scoliosis have been improved, and major complications have been minimized.     

Congenital retardation and central motor defect with later evolution of seizure disorder, orofacial dysplasia, and amyotrophy. A clinicopathologic report

Retarded mental and motor development was observed during the first year of life of a full-term female who had been delivered with difficulty. Generalized psychomotor seizures and dysplastic "acromegalic" facial changes began to develop when she was 8 years old, and generalized amyotrophy developed over the next several years. The course was generally progressive, and she died at age 31. A variety of clinical laboratory studies were nondiagnostic. Autopsy findings showed normal brain weight and normal-appearing cerebral hemispheres, a peculiar atrophy of the inferior portion of the cerebellar hemispheres, a demyelinating process in the dorsal columns of the cervical and thoracic spinal cord, and lateral column and motor neuron degeneration. The pathogenesis of the syndrome is undetermined.     

The lordotic effect of the OSI frame on operative adolescent idiopathic scoliosis patients

STUDY DESIGN: A prospective evaluation of adolescent idiopathic scoliosis patients undergoing operative treatment on the Orthopedic Systems Incorporated (OSI; Jackson) frame. OBJECTIVES: To investigate prospectively thoracic, thoracolumbar, and lumbar sagittal alignments in patients with adolescent idiopathic scoliosis who undergo an instrumented posterior spinal fusion on the OSI frame. SUMMARY OF BACKGROUND DATA: In several studies, it has been shown that patient positioning on various operative frames is an important component of ultimate lumbar sagittal alignment. However, these studies have all concentrated on the lumbar spine, and no sagittal plane alignment data in adolescent idiopathic scoliosis patients have been reported in the thoracic and thoracolumbar junction as it relates to intraoperative positioning, correction maneuvers and correlative postoperative results. METHODS: Thirty-nine patients with operative adolescent idiopathic scoliosis treated with an instrumented posterior spinal fusion on the OSI frame were prospectively evaluated. Standing preoperative, intraoperative, and postoperative long-cassette lateral radiographs were reviewed with regional and segmental Cobb measurements of the thoracic, thoracolumbar junction, and lumbar spine obtained. RESULTS: Thoracic kyphosis (T1-T12) measured +34 degrees before surgery, +28 degrees during surgery, and +30 degrees after surgery, Thus, a statistically significant decrease was noted in thoracic kyphosis secondary to prone positioning on the OSI frame ( P < 0.05). Thoracolumbar spine measurements from T10 to L2 also showed a lordotic trend from +2 degrees before surgery, to -4 degrees during surgery, to -8 degrees after surgery, which was also statistically significant (P < 0.05). Total lumbar lordosis from T12 to S1 remained relatively unchanged from -60 degrees before surgery, to -59 degrees during surgery, to -60 degrees after surgery. However, segmental lumbar lordosis measured from T12 to the lowest instrumented vertebra showed a statistically significant increase in lordosis from -17 degrees before surgery, to -19 degrees during surgery, to -23 degrees after surgery (P < 0.05). Those patients in whom lumbar pedicle screws were used (vs. hooks alone) had the greatest increase in lumbar instrumented lordosis. CONCLUSIONS: Performing adolescent idiopathic scoliosis correction on the OSI frame tends to decrease thoracic kyphosis, increase thoracolumbar lordosis, and increase segmental instrumented lumbar lordosis, while it maintains total lumbar lordosis.     

Perioperative complications of anterior procedures on the spine

We reviewed the operative and hospital records of 447 patients in order to determine the rates of perioperative complications associated with an anterior procedure on the thoracic, thoracolumbar, or lumbar spine. The anterior procedures were performed to treat spinal deformity or for débridement or decompression of the spinal canal. The diagnostic groups that we studied included idiopathic scoliosis in adolescents or young adults (100 patients), scoliosis in mature adults (sixty-three patients), kyphosis (sixty-one patients), neuromuscular scoliosis (sixty patients), fracture (forty-seven patients), a revision procedure (thirty-nine patients), congenital scoliosis (thirty-six patients), tumor (nineteen patients), vertebral osteomyelitis or discitis (eight patients), and miscellaneous (fourteen patients). Complications occurred in 140 (31 per cent) of the 447 patients and were classified as major or minor. Forty-seven patients (11 per cent) had at least one major complication and 109 (24 per cent) had at least one minor complication. Two patients died, both from pulmonary complications after the operation. The most common type of major complication was pulmonary; the most common type of minor complication was genito-urinary. The adolescent or young adult patients who had idiopathic scoliosis had the lowest rate of complications, and the patients who had neuromuscular scoliosis had the highest. An age of more than sixty years at the time of the operation was associated with a higher risk of complications. The duration of the procedures involving a thoracic approach was shorter than that of those involving a thoracolumbar or lumbar approach; however, the rate of complications was not significantly different among the three approaches. Vertebrectomies took longer to perform and were associated with a greater estimated blood loss than discectomies; however, there was no significant difference in the rate of complications between the two types of procedures. The patients who had a fracture or a tumor lost more blood than those from the other diagnostic groups. Blood loss increased as the duration of the operation increased for all procedures. Combined anterior and posterior procedures performed during the same anesthesia session were associated with a higher rate of major complications than were procedures that were staged. A logistical regression analysis showed that the variables that increased the risk of a major complication were an estimated blood loss of more than 520 milliliters and an anterior and posterior procedure performed sequentially under the same anesthesia session. This analysis also demonstrated that the diagnosis of idiopathic scoliosis in adolescents or young adults was associated with a reduced risk of major complications. Compared with other major operations, an anterior procedure on the thoracic, thoracolumbar, or lumbar spine performed for the indications mentioned in this study is relatively safe.     

Effect of extradural analgesia on the paradoxical arousal response of the electroencephalogram

Nineteen patients with Duchenne's muscular dystrophy underwent segmental spinal instrumentation and posterior fusion between 1989 and 1994. The indication for surgery was loss of the ability to walk and development of scoliosis with sitting discomfort. Preoperative assessment included evaluation of pulmonary function. Average age at operation was 12.5 years. Instrumentation and fusion extended from upper thoracic levels to L-5 or the sacrum. A Hartshill rectangle was used in all cases, with banked allograft bone. Severe intraoperative blood loss was avoided by use of hypotensive anaesthesia. Peroperatively, systolic blood pressure was maintained between 75 and 85 mm Hg. Average blood loss was 1,246 ml (range, 400-3,100) or 30% of estimated total blood volume. Average transfusion requirements were 3 units of packed cells. Postoperative analgesia was provided by infusion via an epidural catheter. There were no postoperative wound or chest infections. Three patients required catheterisation for urinary retention. Postoperatively patients were fitted with a Neofract jacket to allow early mobilisation and discharge. Mean postoperative length of stay was 16 days. Posterior spinal fusion by using the Hartshill rectangle provided good correction and fixation. Hypotensive anaesthesia permitted surgery to be performed rapidly in a relatively dry field and avoided the complications of severe intraoperative blood loss and massive transfusion.     

Natural history of scoliosis in spastic cerebral palsy

BACKGROUND: Although the frequent occurrence of scoliosis in patients who have spastic cerebral palsy is well known and surgical treatment has often been recommended for these patients, little is known about the natural history of scoliosis in this population. We aimed to clarify the natural history of scoliosis from childhood through to adulthood and provide objective data on proper surgical indications for such patients. METHODS: The participants were 37 institutionalised patients with severe spastic cerebral palsy and scoliosis. All the participants had a series of radiographs taken, starting at a mean age of 7.8 years; they were followed up for an average of 17.3 years. We retrospectively reviewed radiographs and assessed the effect of five factors on progression of scoliosis: sex, degree of spasticity, initial physical capability, pattern of spinal curve, and location of curve. FINDINGS: Scoliosis usually started before the age of 10 years and progressed rapidly during the growth period. In many cases, even after growth had ended, continuous progression was seen. The mean magnitude of the curves at final examination was 55 degrees (Cobb angle). In 11 (85%) of 13 patients who had a spinal curve of more than 40 degrees before age 15 years, the scoliosis progressed to more than 60 degrees by the time of the final examination. Meanwhile, in only three (13%) of 24 patients who had a curve of less than 40 degrees at age 15 years, did the scoliosis progress to more than 60 degrees. Severe scoliosis (> or = 60 degrees) developed predominantly in those who had total body involvement (67%), were bedridden (100%), or had throacolumbar curves (57%). INTERPRETATION: The risk factors for progression of scoliosis in spastic cerebral palsy are: having a spinal curve of 40 degrees before age 15 years; having total body involvement; being bedridden; and having a thoracolumbar curve. Patients with these risk factors might benefit from early surgical intervention to prevent progression to severe scoliosis.     

Spontaneous thoracic spinal cord herniation. A case report

STUDY DESIGN: This is a case report. OBJECTIVE: To focus attention on spontaneous spinal cord herniation as a rare cause of myelopathy that can be diagnosed preoperatively and can be corrected surgically. SUMMARY OF BACKGROUND DATA: A 34-year-old woman presented with spastic paraparesis. Magnetic resonance imaging scan of the thoracic spine revealed anterior displacement and tethering of the cord at T6-T7 and a dorsal intradural arachnoid cyst. Excision of the cyst was performed without improvement in symptomatology. During reoperation the thoracic spinal cord hernia was discovered and was reduced intradurally. METHODS: The authors describe the clinical, radiographic, and surgical findings of this patient and review the findings from other reported cases. They discuss the proposed theories for the pathophysiology of the cord herniation and the surgical management. RESULTS: The patient had idiopathic thoracic spinal cord herniation as there was no history of previous spine surgery or injury. The authors believe that the cord herniated through a congenital dural defect, which resulted in the development of a pseudoarachnoid cyst dorsally to the hernia. The patient improved after intradural reduction of the hernia and closure of the dural defect. CONCLUSION: Idiopathic spinal cord herniation should be recognized as a cause of progressive myelopathy that can be managed successfully with microsurgical techniques.     

Refined crystal structure and mutagenesis of human granulocyte-macrophage colony-stimulating factor

We reviewed the clinical and technical outcomes of 25 patients with neuromuscular scoliosis, who were treated by Luque instrumentation and posterior spinal fusion from the upper thoracic spine to L5 between 1981 and 1988. A mean curve correction of 46% was obtained operatively with a mean 8 degrees loss of correction during the follow-up period that ranged from 1.9 to 9.4 years (mean, 5.5). Pelvic obliquity was improved 50% from a mean of 16.1 degrees to a mean of 8.1 degrees in 24 patients for whom data were available. At final follow-up, the mean pelvic obliquity increased to 11.4 degrees with only two patients increasing > 8 degrees. The cause for major postoperative increase in pelvic obliquity was continued anterior spinal growth with torsion of the fusion mass and was not related to changes limited to the L5-S1 motion segment. Posterior fusion and instrumentation from the upper thoracic spine to L5 without anterior fusion provides adequate correction and control of spinal deformity for many patients with cerebral palsy. Those patients with significant growth remaining, or with severe deformities, may benefit by preliminary anterior release and fusion or inclusion of the pelvis and sacrum.     

Use of ultrasound in spinal arthrodesis. A rabbit model

STUDY DESIGN: The biomechanical and histologic characteristics of posterolateral spinal fusion in a rabbit model with and without the application of low-intensity ultrasound were analyzed. OBJECTIVES: To evaluate the use of ultrasound to improve the spinal fusion rate and biomechanical characteristics of the fusion mass in a rabbit model. SUMMARY OF BACKGROUND DATA: This is the first study in which the benefits of ultrasound in spinal fusion have been assessed. Posterolateral intertransverse process fusion in the rabbit has a pseudarthrosis rate similar to that recorded in humans (5-40%). METHODS: Fourteen New Zealand White rabbits were randomly assigned to each of two groups to undergo spinal fusion using autologous bone with ultrasound or autologous bone without ultrasound. A specially designed plastic constraint was used to focus the ultrasound over the rabbits' lumbar spine 20 minutes per day. Animals were killed at 6 weeks for biomechanical and histologic testing. RESULTS: The rate of pseudarthrosis, evaluated radiographically and manually in a blinded fashion, decreased at a statistically significant rate (from 35% to 7%) with ultrasound. Biomechanical analysis of the fusion mass showed that ultrasound resulted in statistically significant increases in stiffness (33%; P = 0.03), area under the load displacement curve (25%; P = 0.05), and load to failure of the fusion mass (24%; P = 0.04). Qualitative histologic assessment showed increased bone formation in those fusions exposed to ultrasound. CONCLUSIONS: Lumbar spinal fusion is a complex biologic process. The results of the current study demonstrate the reproducibility of a rabbit fusion model and the ability of ultrasound to induce a statistically significant increase in fusion rate, stiffness, area under the load displacement curve, and load to failure of the fusion mass. These results provide a basis for continued evaluation of biologic improvement of spinal arthrodesis with the use of ultrasound.     

New anterior instrumentation for the management of thoracolumbar and lumbar scoliosis. Application of the Kaneda two-rod system

STUDY DESIGN: The Kaneda multisegmental instrumentation is a new anterior two-rod system for the correction of thoracolumbar and lumbar spine deformities. This system consists of a vertebral plate and two vertebral screws for individual vertebral bodies and two semirigid rods to interconnect the vertebral screws. Clinical results of 25 thoracolumbar and lumbar scoliosis patients treated with this new instrumentation were analyzed. OBJECTIVES: To evaluate the efficacy of the new anterior instrumentation in correction and stabilization of thoracolumbar and lumbar scoliosis. SUMMARY OF BACKGROUND DATA: Since Dwyer first introduced the concept of anterior spinal instrumentation and fusion for scoliosis, anterior surgery has gradually gained acceptance. In 1976, a useful modification for the anterior spinal instrumentation, which reportedly provided means of lordosation and vertebral body derotation, was described. However, some authors reported a high tendency of the implant breakage, loss of correction, progression of the kyphosis, and pseudoarthrosis as the major complications. To overcome the disadvantages of Zielke instrumentation, the authors have developed a new anterior spinal instrumentation (two-rod system) for the management of thoracolumbar and lumbar scoliosis. METHODS: Anterior correction and fusion using Kaneda multisegmental instrumentation was performed in 25 patients with thoracolumbar or lumbar scoliosis. The average follow-up period was 3 years, 1 month (range, 2 years to 4 years, 7 months). There were 20 patients with idiopathic scoliosis (13 adolescents and seven adults) and five patients with other types of scoliosis, including congenital and other etiologies. All patients had correction of scoliosis by fusion within the major curve, and for 16 of the 25 patients, the most distal end vertebra was not included in the fusion (short fusion). Radiographic evaluations were performed to analyze frontal and sagittal alignments of the spine. RESULTS: The average correction rate of scoliosis was 83%. Over the instrumented levels, the correction rate was 90%. Preoperative kyphosis of the instrumented levels of 7 degrees was corrected to 9 degrees of lordosis. Sagittal lordosis of the lumbosacral area beneath the fused segments averaged 51 degrees before surgery and was reduced to 34 degrees after surgery. The trunk shift was improved from 25 mm before surgery to 4 mm at final follow-up evaluation. The average improvement in the lower end vertebra tilt-angle was 97% in those patients whose lower end vertebra was included in the fusion and 83% in patients whose lower end vertebra was not included in the fusion. Apical vertebral rotation showed an average correction rate of 86%. At final follow-up evaluation, all patients demonstrated solid fusion without implant-related complications. There was 1.5 degrees of frontal plane and 1.5 degrees of sagittal plane correction loss within the instrumented area at final follow-up evaluation. CONCLUSIONS: New anterior two-rod system showed excellent correction of the frontal curvature and sagittal alignment with extremely high correction capability of rotational deformities. Furthermore, correction of thoracolumbar kyphosis to physiologic lordosis was achieved. This system provides flexibility of the implant for smooth application to the deformed spine and overall rigidity to correct the deformity and maintain the fixation without a significant loss of correction or implant failure compared with conventional one-rod instrumentation systems in anterior scoliosis correction.     

Progressive congenital kyphosis: report of five cases and review of the literature

For over 60 years congenital kyphotic deformities of the spine have been categorized into two distinct groups, depending on the developmental defect. Those arising from a failure of formation of the vertebral bodies were classified as type 1, while those arising from a failure of segmentation were referred to as type 2. Recognition of the progressive and unstable nature of the type 1 defects alerted physicians to the need for early operative stabilization through decompression and stabilization through instrumentation. As the embryogenesis of the spinal column was further investigated, and as diagnostic imaging methods of the spine improved, unstable congenital kyphoses were further subdivided. Progressive congenital kyphotic deformities now may accompany a host of vertebral column developmental defects as well as genetically mediated mesenchymal tissue defect syndromes. This paper presents 5 patients from The Children's Hospital of Philadelphia with progressive and symptomatic congenital kyphotic deformities of the spine. Two of these lesions resulted from defects of formation of the vertebral bodies, while one resulted from segmental spinal dysgenesis, maldevelopment of both the anterior and posterior vertebral elements. One patient's kyphotic deformity was a result of caudal regression syndrome, and the final case presented experienced a high thoracic kyphosis from a syndrome associated diffuse midline mesenchymal tissue abnormalities known as cerebrocostomandibular syndrome. All patients showed evidence of progressive cord compression and required neural element decompression, fusion, and instrumentation. The cases are discussed individually, and the developmental and clinical aspects of each are explored.     

Spinal deformity in myelodysplasia. Correction with posterior pedicle screw instrumentation

STUDY DESIGN: A retrospective review of transpedicular instrumentation used in a series of 24 patients with myelodysplastic spinal deformities and deficient posterior elements. OBJECTIVE: To describe the usefulness and efficacy of these instruments in the treatment of complicated myelodysplastic spinal deformity. METHODS: The mean preoperative scoliosis was 75.7 degrees (range, 39-130 degrees) in the 22 patients with scoliotic deformities; 4 patients with thoracic hyperkyphoses averaged 70.5 degrees (range, 46-90 degrees) and 10 patients with lumbar kyphoses averaged 80.5 degrees (range, 42-120 degrees). The instrumentation extended to the sacrum in 4 patients and the pelvis in 9; 10 patients also underwent anterior release and fusion and 7 underwent concomitant spinal cord detethering. At an average follow-up of 4.0 years (2.0-7.7 years; one patient died at 8 months), all patients have fused (with the exception of two lumbosacral pseudarthroses). RESULTS: At last follow-up, deformity measured 32.1 degrees scoliosis (range, 6-85 degrees), 30.8 degrees thoracic kyphosis (range, 24-35 degrees), and 0.0 degree lumbar kyphosis (range, 35 degrees kyphosis to 29 degrees lordosis). Three patients lost some neurologic function after surgery; two recovered within 6 months and one has incomplete recovery. No ambulatory patient lost the ability to walk. Five patients required additional surgical procedures; in three cases, there was instrumentation breakage associated with pseudarthrosis or unfused spinal segments. CONCLUSIONS: Pedicle screw instrumentation is uniquely suited to the deficient myelodysplastic spine. Compared with historical control subjects, these devices have proven capable of significant correction of both scoliotic and kyphotic deformities. This instrumentation appears particularly useful in preserving lumbar lordosis in all patients and may preserve more lumbar motion in ambulatory myelodysplasia patients.