Management of neuromuscular spinal deformities with Luque segmental instrumentation

Forty-six patients who had a neuromuscular spinal deformity were treated with arthrodesis and Luque segmental spinal instrumentation and were followed for an average of three years. Twenty-two patients had cerebral palsy and twenty-four had another neuromuscular disease. In thirty-nine patients, the arthrodesis was extended to the sacrum. Eleven patients who had severe scoliosis as well as pelvic obliquity and decompensation of the torso had a combined anterior and posterior arthrodesis; the other thirty-five patients had a one-stage posterior procedure. Preoperatively, the average scoliosis was 74 degrees; this was corrected to 39 degrees at follow-up. Final corrections were similar for scoliosis and were better for pelvic obliquity and decompensation of the torso in patients who had combined anterior and posterior arthrodesis. The results for scoliosis and pelvic obliquity in patients who had a spastic deformity were similar to the results in patients who had a flaccid deformity. Correction of decompensation of the torso was better in patients who had a spastic deformity. Postoperatively, a brace was used in half of the patients in each group; this did not appear to affect the amount of correction in either group, although the result may have been influenced by the selection process. The rate of complications was 48 per cent. Pseudarthrosis occurred in three patients (6.5 per cent). There were no major neurological deficits related to the correction or to the use of sublaminar wires. Three patients died, one in the immediate postoperative period and the other two at eighteen months and four years after the original procedure, due to causes unrelated to the operation.     

Combined anterior and posterior fusion for spinal deformity in myelomeningocele

Since 1973, 50 of 54 children have been treated by the author with a combined anterior and posterior fusion. Twenty males and 34 females, ranging in age from 1 to 16 years, have been followed for a mean period of 5.5 years. Sixteen patients with a kyphosis averaging 113 degrees (range, 77 to 170 degrees) had correction of deformity to a mean of 35 degrees. Thirty-seven patients with a scoliosis averaging 73 degrees (range, 20 to 135 degrees) had correction to an average of 34 degrees (range, 0 to 75 degrees). There were 4 cases of deep wound infection successfully treated with drainage and antibiotics and only one case required implant removal after fusion/maturation. A pseudarthrosis was noted by radiograph in 6 patients, 3 of whom had isolated asymptomatic lumbosacral pseudarthroses. Three patients had pseudarthrosis at the thoracolumbar junction. These required repair and were successfully treated by supplemental posterior fusion resulting in an overall pseudarthrosis rate of 5.7%. Anterior fusion of the dysraphic spine allows greater correction of both spinal deformity and pelvic obliquity in addition to contributing significant strength to the fusion mass. Segmental spinal instrumentation with sublaminar and pedicular wiring to custom-contoured Luque rods provides excellent correction and immediate postoperative stability.     

Treatment of selected neuromuscular patients with posterior instrumentation and arthrodesis ending with lumbar pedicle screw anchorage

STUDY DESIGN: This is a retrospective analysis of 23 patients with severe neuromuscular spinal deformity treated with posterior instrumentation and fusion ending in the lumbar spine. OBJECTIVES: The purposes of this study were to determine the safety and efficacy of stopping posterior instrumentation constructs in the lumbar spine with pedicle screw anchorage. SUMMARY OF BACKGROUND DATA: There are sparse data in the peer-reviewed literature regarding indications and outcomes in patients with neuromuscular disorders for instrumented fusion ended short of the pelvis with transpedicular fixation. METHODS: The average age of patients at surgery was 18.4 years (range, 10-61 years). Additional anterior discectomy and fusion were performed in four patients with large, stiff curves. No patient received anterior instrumentation. Criteria for exclusion of the pelvis from the fusion were less than 15 degrees of pelvic obliquity as a result of a compensatory curve below the major curve(s), the absence of problematic lower extremity contractures, and, often, the potential for ambulation. Process and clinical outcomes and complications were analyzed. RESULTS: Radiographic follow-up was available in 21 patients at an average of 62 months (range, 24-110 months) after surgery. Their average Cobb angle was 71 degrees before surgery, 25 degrees after surgery (64% correction), and 32 degrees at follow-up (54% correction). Their average spinal-pelvic obliquity was 6 degrees before surgery, 5 degrees after surgery, and 6 degrees at follow-up. The average lower instrumented vertebra was lumbar 3.7. Clinical follow-up was available for all 23 patients for an average of 61 months (range, 24-110 months). There were no perioperative deaths, deep wound infections, pseudarthroses, or instrument failures. Outcomes based on responses to questionnaires completed by patient, parent, or caregiver were highly satisfactory in 20 patients (87%), satisfactory in 2 patients (9%) and neither satisfactory nor unsatisfactory in 1 patient (4%). CONCLUSION: Posterior instrumentation and arthrodesis using lumbar lower instrumented vertebra pedicle screw anchorage can be performed safely and effectively, in selected patients patients with scoliosis and minimal pelvic obliquity.     

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.     

Pseudarthrosis in adult spinal deformity following multisegmental instrumentation and arthrodesis

BACKGROUND: There have been few detailed reports concerning pseudarthrosis following spinal instrumentation and arthrodesis in adults with spinal deformity since the introduction of modern segmental fixation techniques. The purposes of this study were to analyze the prevalence, risk factors, and outcome scores on the Scoliosis Research Society Instrument-24 associated with pseudarthrosis following instrumentation and arthrodesis for the treatment of spinal deformity in adults. METHODS: A clinical and radiographic assessment of 232 adults with spinal deformity who were treated surgically at a single institution was conducted. The average age of the patients was 40.8 years, and the operation was a primary procedure in 150 patients and a revision procedure in eighty-two patients. All patients who underwent a long (four vertebrae or more) spinal instrumentation and arthrodesis with a minimum follow-up of two years were included in the analysis. Clinical outcomes were assessed with the Scoliosis Research Society questionnaire. RESULTS: Forty patients had a pseudarthrosis. Factors that were found to be significantly associated with pseudarthrosis were preoperative thoracolumbar kyphosis of >20 degrees (p < 0.0001), an age of more than fifty-five years (p = 0.001), arthrodesis to S1 compared with arthrodesis to L5 or a cephalad level (p = 0.002), and arthrodesis of more than twelve vertebrae (p = 0.037). Patients with a pseudarthrosis had lower total outcome scores on the Scoliosis Research Society questionnaire, on the average, than those without a pseudarthrosis (p = 0.001). CONCLUSIONS: The prevalence of pseudarthrosis following long arthrodesis with use of modern segmental spinal instrumentation for the treatment of spinal deformity in adults was 17%, and the clinical outcome in these patients can be negatively affected by the pseudarthrosis.     

Surgery of spinal deformity in cerebral palsy. Twelve years in the evolution of scoliosis management

In order to assess the lessons learned from 12 years of surgery on patients with cerebral palsy and spinal deformity, the cases may be divided into three groups classified according to type of posterior spinal fusion, instrumentation, and time period. Group I (1976-1980) included patients who had Harrington rods, usually with Dwyer instrumentation. Group II (1980-1985) consisted of patients with unlinked Luque or wired-in Harrington rods. Group III (1985-1988) comprised patients with a unit Luque rod extending to the pelvis. Most patients were retarded nonwalkers who had total body involvement, pelvic obliquity, and severe thoracolumbar curves (Group I average, 97 degrees; Group II average, 72 degrees; Group III average, 89 degrees). The frontal plane correction at follow-up study averaged 51% in Group I, 47% in Group II, and 76% in Group III. The correction of the pelvic obliquity averaged 71% in Group I, 58% in Group II, and 86% in Group III. The general trend was toward longer fusion, use of the unit 0.625-cm Luque rod, and first-stage anterior discectomy and fusion without anterior instrumentation. The second-stage posterior arthrodesis and fusion is now performed only one week after the first-stage anterior procedure. Skeletal traction has been abandoned. The Luque rod instrumentation without fusion has also been abandoned.     

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.     

Lumbosacral fusion in children and adolescents using the modified sacral bar technique.

Between 1986 and 1995 10 patients who were 9 to 18 years of age underwent posterior spinal fusion and instrumentation to the pelvis for correction of spinal deformity using the modified sacral bar technique at the authors' institution. Etiologies of the spinal deformity included congenital scoliosis, cerebral palsy, myelomeningocele, neurofibromatosis, and postlaminectomy kyphosis. Indications for pelvic instrumentation were progressive scoliosis of the lower lumbar spine, pelvic obliquity greater than 15 degrees, and dysraphic posterior elements. Five of the patients had prior spinal surgery. Five patients had a prior or a planned pelvic osteotomy. Nine of the patients achieved lumbosacral fusion without an additional procedure. Major complications included loss of pelvic fixation in two patients, and a dural leak and a wound infection in another patient with myelomeningocele. Mean scoliotic curve correction was from 71.9 degrees to 34.5 degrees at final followup. Lumbar lordosis essentially was unchanged. Pelvic obliquity was corrected from a mean of 20.5 degrees preoperatively to a mean of 7.6 degrees at final followup. The modified sacral bar technique was selected for fusion to the sacrum because of planned or prior pelvic osteotomies, prior posterior spinal fusion and instrumentation, sacral dysraphism, or local anatomic anomalies. The modified sacral bar technique proved to be an effective technique in these patients.     

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.     

Anterior and posterior spinal fusion for paralytic scoliosis

Twenty-three patients with paralytic scoliosis were treated with a combination of anterior and posterior spinal instrumentation and fusion. The sequence was anterior surgery first in 19 patients and posterior surgery first in 4. The average age was 14.4 years. Preoperative correction with a halo-hoop apparatus was performed in 12 patients. The average preoperative curve for the group measured 100 degrees, and the average postoperative curve at a mean follow-up time of 21 months was 37 degrees. The mean loss of correction was 8 degrees. Although superior hook dislodgment occurred in 5 patients, no pseudarthrosis or beinding of the fusion mass was documented.     

Adult idiopathic scoliosis treated by posterior spinal fusion and Harrington instrumentation

Ninety-one patients with idiopathic scoliosis, who underwent posterior spinal fusion and instrumentation from January 1977 to December 1982, were reviewed. All patients were 20 years or older at the time of surgery and none had undergone a prior surgical procedure. Indications for surgery included pain, progressive deformity, and pulmonary symptoms. All patients had a posterior spinal fusion with Harrington instrumentation and autogenous iliac bone graft, with the addition of segmental wiring in only eight. No patient had an anterior fusion or fusion to the sacrum. Follow-up averaged 3.5 years (range: 2-7 years). The average correction at the time of surgery was 38%, and 32% at the time of last follow-up. Seventy-nine percent of the patients reported complete relief of the symptom(s) for which they had surgery. There were 34 complications in 30 (33%) patients. Pseudarthrosis occurred in 14 (15%), requiring 15 additional procedures to achieve a solid arthrodesis. Urinary tract infection occurred in 8 (9%) patients and Harrington hook dislodgement in 5 (5%). One patient sustained a partial paraparesis with recovery to a minimal deficit. No deaths occurred. Although largely successful, posterior fusion with Harrington instrumentation for adult scoliosis has a significant incidence of pseudarthrosis and instrumentation problems.     

Spine fusion in cerebral palsy with L-rod segmental spinal instrumentation. A comparison of single and two-stage combined approach with Zielke instrumentation

The benefits of achieving rigid internal fixation and eliminating the need for postoperative external orthotic support with L-rod spinal instrumentation made it desirable for use in the surgical treatment of neuromuscular scoliosis. From May 1981 to May 1985, 31 severely involved cerebral palsy patients with progressive spinal deformity underwent posterior fusion and L-rod instrumentation. All patients except one were nonambulatory. Surgical indications included prevention of curve progression, correction of pelvic obliquity, and achievement of balanced spinal alignment in order to improve sitting balance and tolerance without external spinal orthotic support. Ten patients (Group I), with an average age of 15.2 years, with double major or flexible paralytic C-curves or scoliosis measuring less than 70 degrees, underwent posterior fusion and L-rod instrumentation only. Twenty-one patients (Group II), with an average age of 22.1 years, with thoracolumbar, lumbar, or rigid paralytic C-curves or scoliosis measuring greater than 70 degrees, underwent initial anterior release, bone grafting, and Zielke instrumentation followed by second-stage L-rod instrumentation. In Group I, scoliosis averaged 57 degrees and postoperatively 27 degrees (53% correction). In Group II, scoliosis averaged 88 degrees and postoperatively 36 degrees (63% correction). Fifteen Group II patients had posterior fusion extend into the sacrum using the Galveston technique. Six Group II patients were not fused into the sacrum. Scoliosis and pelvic obliquity were corrected in both groups. Torso decompensation improved to 2.7 cm in the Galveston group, but increased to 5.6 cm at follow-up in the patients not fused into the sacrum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simultaneous correction of pelvic obliquity, frontal plane, and sagittal plane deformities in neuromuscular scoliosis using a unit rod with segmental sublaminar wires: a preliminary report

Ten patients with neuromuscular scoliosis and pelvic obliquity had segmental spinal instrumentation using a unit Luque rod with sublaminar wires and fixation into the pelvis. Nine of the 10 patients also had anterior spinal fusion without instrumentation before the posterior procedure. Average preoperative pelvic obliquity was 42 degrees which was corrected to 6 degrees (82% correction). Average preoperative scoliosis was 92 degrees, which was corrected to 16 degrees (81% correction). Complications included a wound hematoma in one patient and a superficial wound dehiscence in another. There have been no pseudarthroses or hardware failures to date. Excellent correction of the pelvic obliquity and the spinal curve in neuromuscular scoliosis can be obtained with use of a unit rod and without use of anterior instrumentation.     

Luque-Galveston procedure for correction and stabilization of neuromuscular scoliosis and pelvic obliquity: a review of 68 patients.

Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion with Luque-Galveston instrumentation between 1982 and 1986. The minimum follow-up was 4 years. Diagnoses included cerebral palsy in 34 patients and other neuromuscular diseases in another 34 patients. The average age was 14 years. Twenty patients also had anterior spine fusion without instrumentation. Preoperatively the average scoliosis was 73 degrees and this was corrected to 33 degrees at final follow-up. The subgroup having anterior discectomy and fusion had a more severe scoliosis and pelvic obliquity, but the percent of correction was similar to that of the group with posterior reconstruction only. Twenty-four patients who had an associated significant sagittal plane deformity were corrected to a physiologic curvature. A postoperative thoracolumbosacral orthosis was used in 27 patients, and a molded seating orthosis was used in 18. Although the rate of complications was high (62%), most of them were minor. Instrumentation problems occurred in 14 patients (21%), only 4 of them having broken rods. There were no broken wires. Pseudarthrosis occurred in seven patients (10%). Three patients had minor neurologic deficits, all transient. The "windshield-wiper" sign was defined as any radiolucency of 2 mm or greater. Twenty-six patients had this sign at follow-up, and this group had a higher percentage of complications, but the existence of this sign did not necessarily indicate a problem.     

Combined staged anterior and posterior correction and fusion of the spine in scoliosis following poliomyelitis.

The problems with severe forms of scoliosis following poliomyelitis include the associated muscle imbalance, soft tissue contractures and pelvic obliquity. Such deformities militate against optimal correction and maintenance of that correction and their treatment is often marred by pseudarthroses. Seventeen patients with an average curve of 93 degrees have been treated and followed for up to 38 months. Preliminary traction was used in 8 patients, then a staged anterior and posterior correction and fusion was done, using Dwyer's instrumentation of the major curve in all and a Harrington rod to supplement the posterior fusion in eleven patients. With this technique the major curve was corrected by 80 per cent with an average 2 per cent loss over 18 months. No pseudarthroses were seen when the Harrington rod was used. Great care must be taken if halo-pelvic traction is to be used for patients with pelvic obliquity, for preliminary correction halo-femoral traction will often be adequate. In the more severe forms of paralytic scoliosis a combined staged anterior and posterior correction and fusion should be considered if the aim is maximal correction of the scoliosis and avoidance of pseudarthroses.     

Analysis of results with Zielke instrumentation for thoracolumbar and lumbar curvature

Thirty-nine patients (idiopathic in 26, paralytic in 11 and congenital in 2) treated by Zielke instrumentation with fusion for thoracolumbar and lumbar curvature were reviewed. The average follow-up was 34 months. The corrections of scoliosis was 76% in the adolescent idiopathic group, 59% in the adult idiopathic group and 55% in the paralytic group; rotation corrected (38%). Kyphosis was reduced from 61 degrees to 20 degrees on the average by derotating the spine using the derotator followed by placing bone graft in the anterior disc spaces. The tilt angle of the lower end vertebra in the idiopathic group and the pelvic obliquity angle in the paralytic group were corrected remarkably. Fusion rate was 92.3%. Two of three pseudarthrosis were repaired by Harrington instrumentation and fusion. One was free from symptoms. Complications were frequent, though in most cases only minor.     

Posterior-only unit rod instrumentation and fusion for neuromuscular scoliosis

STUDY DESIGN: A retrospective study to determine the efficacy of posterior-only unit rod instrumentation and fusion in a skeletally immature neuromuscular scoliosis population. OBJECTIVE: To determine whether the posterior-only approach to this population adequately addresses the concerns of correction of scoliosis and pelvic obliquity, maintenance of that correction over time, and the incidence of crankshaft phenomenon. SUMMARY OF BACKGROUND DATA: Controversy exists regarding the need for anterior release to improve curve flexibility and the need to obtain an anterior arthrodesis in those skeletally immature patients at risk for crankshafting with continued anterior growth. METHODS: From 1992 through 1997, 28 consecutive skeletally immature patients with neuromuscular scoliosis underwent posterior-only unit rod instrumentation and fusion for the treatment of progressive, symptomatic spinal deformities. Preoperative, immediate postoperative, and final follow-up radiographs were analyzed with respect to scoliosis and pelvic obliquity correction, maintenance of that correction over time, and the development of the crankshaft phenomenon as evidenced by loss of correction and/or increased rib-vertebral angle difference. The average age of the patients was 12.8 years and the average follow-up was 58 months with a minimum of 2 years. RESULTS: Twenty-six patients were available for final follow-up. The initial Cobb angle correction averaged 66%, with 75% of the pelvic obliquity corrected. These corrections were maintained over time. Before surgery 27 of 28 patients were Risser 0, 1, or 2. The triradiate cartilage was open in nine patients, and five patients were < or =10 years of age. At the final follow-up 22 of the 26 patients were Risser 5 and 4 were Risser 4. There was one patient with increased rib-vertebral angle difference over the length of follow-up, with no loss of frontal or sagittal plane alignment. CONCLUSIONS: These results indicate that even in the very young neuromuscular patient, acceptable amounts of curve correction can be achieved and maintained with posterior-only unit rod instrumentation and fusion. The biomechanical stiffness of this construct seemed to be able to prevent the crankshaft phenomenon in the majority of those patients at risk.     

Spinal fusions to the pelvis augmented by Cotrel-Dubousset instrumentation for neuromuscular scoliosis.

Eighteen patients with spinal deformity secondary to a neuromuscular disorder were treated with posterior fusion using Cotrel-Dubousset instrumentation (CDI) to the pelvis. The mean frontal plane curve was 70 degrees preoperatively and 38 degrees postoperatively. The mean loss of correction was 3 degrees at an average follow-up of 28 months. Pelvic obliquity improved in nine patients from a preoperative mean of 22 degrees to 11 degrees at follow-up. Lumbar lordosis was maintained with preoperative and postoperative means of -36 degrees. Complications included perioperative hardware failure in one case and one late, deep infection. There were no neurologic complications, pseudarthroses, or rod breakage. Posterior spinal fusion with CDI to the pelvis is an effective treatment for patients with neuromuscular scoliosis.