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.     

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.     

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.     

Translaminar screw fixation of the lumbar and lumbosacral spine. A 5-year follow-up

STUDY DESIGN: In a retrospective study, the long-term results of translaminar facet screw fixation of the lumbar and lumbosacral spine are reviewed. OBJECTIVES: To evaluate the clinical results, fusion rates and complications of this posterior fusion technique in various conditions of the lumbar spine. SUMMARY OF BACKGROUND DATA: Posterior fusion of the lumbar and lumbosacral spine is one of the possible methods to relieve pain and eliminate instability in degenerative conditions. Data in the literature support the use of internal fixation to optimize the rate of fusion. METHODS: Posterior lumbar and lumbosacral fixation with translaminar screws and fusion in 173 patients with degenerative changes with or without compressive syndromes including failed back syndromes, monosegmental hypermobilities, and posttraumatic conditions were investigated. Fixation and fusion with translaminar screws was performed in 57% monosegmentally, in 40% across two segments and in 2% over three segments. Decompressive surgery was performed in addition in 52% and nucleotomy in 30% of the cases. Clinical and radiologic assessment with flexion/extension x-rays was performed in 145 (83%) patients by two independent orthopedic surgeons. After an average follow-up of 68 months (range, 52-83). RESULTS: Ninety-four percent of the patients showed solid bony fusion in the radiologic follow-up. Loosening of the screws was noted in 3%, and two screws were broken without apparent motion on the functional x-rays. Pain scores decreased from 7.6 before surgery to 2.9 after surgery on a 10-point pain scale. The results were further analyzed according to Stauffer and Coventry with 99 good results, 70 satisfactory results, and 4 bad results. CONCLUSIONS: Translaminar screw fixation offers an immediate postoperative stability of the lumbar and lumbosacral spine and enhances fusion. In the present series no neurologic complications were noted. It represents a useful and inexpensive technique for short segment fusion of the nontraumatic lumbar and lumbosacral spine.     

Internal fixation of the thoracic and lumbar spine using Roy-Camille plates

Thirty patients underwent fixation of the thoracic and lumbar spine from 1986 to 1990 using the Roy-Camille pedicular screw fixation system. The spine was stabilized for a variety of pathologic entities including fracture, tumor, spondylolisthesis, postlaminectomy instability, and pseudarthrosis. All but one patient obtained solid fusion based on radiographic and clinical criteria with an average follow up of 19.5 months. All patients reported subjective improvement in preoperative pain levels. There were no neurologic complications associated with the surgical procedure. Roy-Camille plate fixation appears to offer a stable surgical construct in the treatment of thoracic and lumbar spine instability.     

A thiophosphate analog of dimyristoylphosphatidyl-inositol-4-phosphate is a substrate for mammalian phosphoinositide-specific phospholipase C

STUDY DESIGN: Forty-two conservatively treated patients with a burst fracture of the thoracic, thoracolumbar, or lumbar spine with more than 25% stenosis of the spinal canal were reviewed more than 1 year after injury to investigate spontaneous remodeling of the spinal canal. OBJECTIVES: To investigate the natural development of the changes in the spinal canal after thoracolumbar burst fractures. SUMMARY OF THE BACKGROUND DATA: Surgical removal of bony fragments from the spinal canal may restore the shape of the spinal canal after burst fractures. However, it was reported that restoration of the spinal canal does not affect the extent of neurologic recovery. METHODS: Using computerized tomography, the authors compared the least sagittal diameter of the spinal canal at the time of injury with the least sagittal diameter at the follow-up examination. RESULTS: Remodeling and reconstitution of the spinal canal takes place within the first 12 months after injury. The mean percentage of the sagittal diameter of the spinal canal was 50% of the normal diameter (50% stenosis) at the time of the fracture and 75% of the normal diameter (25% stenosis) at the follow-up examination. The correlation was positive between the increase in the sagittal diameter of the spinal canal and the initial percentage stenosis. There was a negative correlation between the increase in the sagittal diameter of the spinal canal and age at time of injury. Remodeling of the spinal canal was not influenced by the presence of a neurologic deficit. CONCLUSION: Conservative management of thoracolumbar burst fractures is followed by a marked degree of spontaneous redevelopment of the deformed spinal canal. Therefore, this study provides a new argument in favor of the conservative management of thoracolumbar burst fractures.     

Sequential or simultaneous, same-day anterior decompression and posterior stabilization in the management of vertebral osteomyelitis of the lumbar spine

STUDY DESIGN: A retrospective clinical study of patients with vertebral osteomyelitis of the lumbar spine necessitating surgical treatment. All patients underwent sequential (same-day) or simultaneous anterior decompression and posterior stabilization of the involved vertebrae. OBJECTIVE: To evaluate the efficacy and clinical out-come of sequential or simultaneous anterior and posterior surgical approaches in the management of vertebral osteomyelitis of the lumbar spine. SUMMARY OF BACKGROUND DATA: Anterior approach alone and staged anterior decompression and posterior stabilization have been advocated as the surgical treatment methods of choice for patients with vertebral osteomyelitis of the lumbar spine. The drawbacks of the latter management plan are the necessity to use external support or the delayed patient mobilization and the need for additional anesthesia and surgical trauma. Sequential (same-day) anterior and posterior approaches are used regularly in the surgical management of scoliosis and other spinal deformities. It would appear advantageous to also use the same strategy (i.e., combined same-day double approaches) in the management of vertebral osteomyelitis of the lumbar spine. METHODS: Ten consecutive patients who had a diagnosis of vertebral osteomyelitis of the lumbar spine underwent combined (same-day) anterior and posterior approaches either in a sequential or simultaneous manner. Indications for surgery included neurologic deficit, abscess formation, instability with localized kyphosis formation, and failure of nonoperative treatment. Patients were evaluated clinically and radiographically after surgery. RESULTS: All 10 patients had uneventful surgery. Only one patient required a second surgical procedure because of expulsion of the anterior bone graft and pull-out of instrumentation. All patients were mobilized within the 2 days immediately after surgery. At the mean follow-up examination 30 months after surgery, all patients had regained their motor function and prior ambulatory status. CONCLUSIONS: Patients with lumbar osteomyelitis necessitating surgery can undergo combined, same-day surgery either in a sequential or simultaneous manner. This is a safe and efficient way to control the infection and stabilize the affected segments, allowing for early mobilization of these sick elderly patients.     

Lumbar spinal canal stenosis associated with progressive degenerative changes of the spine. A case report

STUDY DESIGN: Case report. OBJECTIVES: To report a case of spinal canal stenosis associated with progressive degenerative changes of the lumbar spine. SUMMARY OF BACKGROUND DATA: As far as the authors are aware, there has been no similar case reported. METHODS: The clinical features of the case are reported, and the pathology is discussed. RESULTS: In a 40-year-old man, spinal canal stenosis developed, associated with progressive degenerative changes of the lumbar spine. The man underwent posterior decompression and fusion using pedicle screws. The surgical results were satisfactory at the time of writing this report. CONCLUSIONS: This case presented a peculiar clinical course, which could not be categorized under previously reported disorders. It may be a new disease entity of spinal canal stenosis. The surgical outcome was satisfactory 2 years, 6 months after surgery.     

Occipitocervical fusion with C1 laminectomy in children

STUDY DESIGN: Eight children in whom atlantoaxial dislocation had developed underwent occipitocervical fusion using a rectangular rod. The postoperative results are presented, and the postoperative growth and deformation of the cervical spine were determined radiographically. OBJECTIVES: To investigate in a relatively long-term follow-up study whether occipitocervical fusion affects the growth of the cervical spine and induces spinal deformation. SUMMARY OF BACKGROUND DATA: It has been reported that children who have undergone C1-C2 posterior fusion are likely to develop abnormal curvature or deformation of the cervical spine as a result of a disturbance of growth of the fused vertebrae. There have been no studies, however, to confirm that these changes occur after occipitocervical fusion in children. METHODS: The subjects were one boy and seven girls who had undergone occipitocervical posterior fusion during childhood. The average age at the time of surgery was 8.3 years, and the average follow-up period was 5.9 years. The following were assessed radiographically: redislocation of the atlas, bone union, changes in the curvature of the cervical spine, the height and width of the vertebral bodies, and the anteroposterior diameter of the spinal canal. RESULTS: Solid bone union was achieved in all patients with maintenance of the reduced position at the time of surgery. None of the patients exhibited abnormal curvature of the cervical spine. The rate of increase in height of the C2 vertebral body was significantly less than that of vertebral bodies below C3. The rate of increase in width of the vertebral body and the anteroposterior diameter of the spinal canal of the C2 vertebral body and vertebral bodies below C3 did not differ significantly. CONCLUSIONS: Occipitocervical fusion with a rectangular rod is useful for treating atlantoaxial dislocation in children and yields excellent results because of the firm internal fixation it achieves. This surgery induced no apparent postoperative spinal deformations.     

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.     

Thoracolumbar burst fractures. The clinical efficacy and outcome of nonoperative management

There continues to be considerable controversy regarding the management of thoracolumbar burst fractures. Most feel that failure of the middle osteoligamentous complex, particularly with retropulsion of fragments into the spinal canal, is an indication for operative management. Others advocate postural reduction and prolonged bedrest for such injuries. The purpose of this study was to 1) review the clinical outcome and efficacy of closed management of thoracolumbar burst fractures; and 2) quantify what, if any, remodeling occurs in the bony canal as measured by serial CT. Forty-one patients who presented with a burst fracture of the thoracolumbar spine without neurologic deficit were reviewed clinically and radiographically following nonoperative management. At injury, canal compromise averaged 37% (range, 16-66%); 26 patients had at least 30% canal compromise. During treatment, one patient developed neurologic deterioration that prompted surgery; all other patients remained neurologically intact. At average follow-up of 2 years, an overall outcome evaluation indicated that 49% of the patients had excellent outcomes relative to pain and function; 17%, good; 22%, fair; and 12%, poor. Approximately 90% of the patients had a satisfactory work status relative to factors associated with their burst fracture. Serial roentgenograms documented significant progression in body collapse, which averaged 8% (P < 0.0001) from injury to follow-up. On the other hand, serial CTs documented significant improvement from injury to follow-up for canal compromise and midsagittal diameter. Average improvements in canal compromise and midsagittal diameter were 22% (P < 0.0001) and 11% (P < 0.0001), respectively. Only three patients had canal compromise greater than 30%, no patients had canal compromise greater than 40%, and no patients experienced canal area deterioration over time. On average, nearly two-thirds of the fragment occluding the canal resorbed, with most remodeling complete within one year. For patients with burst fractures presenting neurologically intact, we obtained the following findings: 1) nonoperative management yields acceptable results; 2) following nonoperative management, bony deformity (i.e., kyphosis and body collapse) progresses marginally relative to the rate of canal area remodeling; 3) incidence of subsequent neurologic deficits is quite low; and 4) initial radiographic severity of injury or residual deformity following closed management does not correlate with symptoms at follow-up. This pattern of results suggests nonoperative management as the preferred treatment in these circumstances.     

Acute abdomen. When to operate immediately and when to observe

BACKGROUND: Seat belt type injury of thoracolumbar spine is an uncommon injury characterized by disruption of the posterior elements of the spine. The fracture has long been treated conservatively, but progressive kyphotic deformity developed frequently. METHODS: From January, 1991 through December, 1992, 10 cases of seat belt type injury of the thoracolumbar spine were encountered at our hospital with an incidence of 8% in overall spinal fractures. Of these patients, eight patients were male and two were female, average age 30.7 years old. The causes included motor-vehicle accident in five patients, fall from height in four, and stricken by a falling electric pole in one. None of the victims of motor vehicle accidents wore seat belt. All of them received open reduction, posterior internal fixation and posterior fusion. RESULTS: After follow-up for an average of 42.2 months, the average kyphotic angulation was 5.7 degrees. Back pain and function of these patients were all rated good. None of them suffered from neurologic deficit. One patient with breakage of transpedicular screws was encountered during follow-up, but there was no complaint. CONCLUSIONS: In treating seat belt type injuries of spinal column, benefits of operation outweigh the risks. Besides, the clinical result is satisfactory and more aggressive surgical approach should be encouraged.     

Transcutaneous or transconjunctival peribulbar anesthesia?

The complications of 648 consecutively inserted Universal AO pedicle screws (140 in the thoracic spine and 508 in the lumbar spine) performed by one surgical team to treat 91 patients with spinal problems, were reviewed. The spinal pathology consisted of: scoliosis (34 patients), degenerative lower lumbar spinal disease (25 patients), neoplastic spinal disease (11 patients), thoracic kyphosis (8 patients), spinal fractures (7 patients), lumbo-sacral spondylolisthesis (3 patients), and osteomyelitis (3 patients). Intraoperative complications were: screw misplacement (n = 3), nerve root impingement (n = 1), cerebrospinal fluid leak (n = 2) and pedicle fracture (n = 2). Postoperative complications were; deep wound infection (n = 4), screw loosening (n = 2) and rod-screw disconnection (n = 1). The conclusion was that pedicle screw fixation has an acceptable complication rate and neurological injury during this procedure is unlikely.     

Comments on "Double-blind comparison of olanzapine versus risperidone in the treatment of schizophrenia and other psychotic disorders" by Tran and Associates

PURPOSE: An unusual case of infantile myofibromatosis with spinal canal involvement is reported and the literature is reviewed. PATIENT AND METHODS: A female neonate had bladder and bowel dysfunction and paresis of the lower extremities. RESULTS: Intrapelvic and paravertebral masses with extension into the spinal canal were detected by imaging studies. In addition, radiologic examination showed multiple metaphyseal radiolucent lesions of the long bones and pathologic fracture of the left femur. The histopathologic diagnosis of the paravertebral tumor and bone lesions was infantile myofibromatosis. Surgical resection of the paravertebral and intrapelvic masses was performed to improve her neurologic impairments. Paresis of the lower limbs gradually improved, whereas bladder and bowel dysfunction remained unchanged. CONCLUSIONS: Only six cases of infantile myofibromatosis associated with spinal canal involvement have been reported. Three patients with flaccid paresis of extremities and respiratory distress died in the newborn period. The other three patients showed improvement of the paresis. The prognosis of infantile myofibromatosis without visceral complication is generally good, but neurologic impairment may occur at birth if the spinal cord is compressed.     

Cervical pseudarthrosis in ankylosing spondylitis. A case report

STUDY DESIGN: This report illustrates two different cases of cervical pseudarthrosis in ankylosing spondylitis. OBJECTIVES: To point out the extreme rarity of this condition at cervical level, to discuss the pathogenesis, and to stress the necessity of surgical management. SUMMARY AND BACKGROUND DATA: Pathogenesis of pseudarthrosis in ankylosing spondylitis is discussed. Several factors are involved: trauma, which may be major or minor and undetected; stress fracture; and inflammatory changes. Major trauma was the cause of pseudarthrosis in the first patient, whereas stress fracture and inflammatory changes were the probable causes in patient 2. In patient 1 there were signs and symptoms of cord compression. Patient 2 was referred because of functional disability resulting from kyphosis and because of potential neurologic risk. METHODS: Cervical fusion was performed in both patients. Patient 1 underwent posterior fusion; patient 2 had combined fusion. Patient 1 also underwent a lamineotomy. RESULTS: The course of the disorder after surgery was uneventful in both patients. Neurologic symptoms subsided in patient 1; kyphosis was corrected in patient 2. Both patients resumed their preoperative activities. Follow-up evaluation was done 6 years after surgery in patient 1 and 2 years after surgery in patient 2. CONCLUSIONS: Pseudarthrosis of the cervical spine in ankylosing spondylitis is extremely rare. Presentation of the two patients was different in terms of pathogenesis and signs and symptoms. Surgical treatment is advocated for this disorder.     

A new approach in the treatment of hypotension in human septic shock by NG-monomethyl-L-arginine, an inhibitor of the nitric oxide synthetase

Between 1987 and 1991, 33 patients with spinal stenosis of the lumbar spine were treated by decompression (33 patients) and posterior fusion (30 patients). Indication for decompression was based on case history and lumbar myelography with flexion/extension views. At follow-up 1-5.5 years later, 28 patients were happy with the results of the treatment and would be willing to be operated on again in a similar situation. Two other patients also presented objectively good results, but were dissatisfied for reasons not related to the operation. Our study shows that myelography and case history are adequate investigations for determination of the level of pathology and for making a decision about operative decompression in spinal stenosis of the lumbar spine. CT or MRI are only needed if the symptoms of the patient are not explained by the myelogram. Although MRI is advocated as the investigation of first choice for lumbar spinal stenosis, we still prefer the myelography, which is easier to interpret during the operation. Our study also shows that operative treatment of spinal stenosis is very rewarding, since 9 out of 10 patients will have good results. We usually combine decompression and fusion. Decompression alone is only performed in patients without any back pain and with stable motion segments after adequate decompression.     

Changes in the unfused lumbar spine in patients with idiopathic scoliosis. A 5- to 9-year assessment after cotrel-dubousset instrumentation

STUDY DESIGN: Postoperative changes in the lumbar spine were studied retrospectively in patients with adolescent idiopathic scoliosis who had been treated with Cotrel-Dubousset instrumentation. OBJECTIVE: To examine middle-term changes in the unfused lumbar segments below an instrumented scoliosis fusion. SUMMARY OF BACKGROUND DATA: Scoliosis fusion by the Harrington method is known to be associated with a flat back in the fused area and subsequent degenerative changes in the segments below the fusion. No data have yet been published concerning a segmental instrumentation system. PATIENTS AND METHODS: Thirty patients with idiopathic scoliosis, between the ages of 14 and 22 years at the time of surgery, were observed for 5-9 years after surgery. Activity, pain, complications, and 21 radiographic parameters were assessed. RESULTS: The prevalence of low back pain increased from 3% before surgery to 20% at the final follow-up visit, although in none of the patients was the pain so severe that specific treatment was required. Radiographically, uninstrumented lumbar segments generally were realigned successfully in the frontal plane. Analyses in the sagittal plane revealed tendencies to a gradual increase in lumbar lordosis, anterior-upward tilting of the lowest instrumented vertebra, and posterior shift of the sagittal spinal balance. During the follow-up period, seven patients (23%) developed degenerative changes, including mild junctional kyphosis, retrolisthesis, narrowing of disc spaces, or osteophytes. CONCLUSION: Whereas the overall clinical and radiographic results of surgery were satisfactory, the unfused lumbar segments required careful surveillance, especially in the sagittal plane.     

Failure of a carbon fiber implant. A case report

STUDY DESIGN: Case report. OBJECTIVES: Failure of a carbon fiber implant. SUMMARY OF BACKGROUND DATA: To simplify the procedure of posterior lumbar interbody fusion, a carbon-fiber-reinforced polymer implant has been developed. The implant has ridges to resist retropulsion, struts to support weight, and a hollow area to allow packing of autologous bone graft. So far, no complications have been reported from the use of carbon implant as a fusion aid in spine surgery. METHODS: A patient with postoperative infection has been followed with computed tomography images and histologic examination from a reoperation. RESULTS: An entire nonunion across the width of the disc space and a clearly broken cage was visualized with computed tomography. The spinal canal was explored during a reoperation and the tissue surrounding the dura and nerves were all black. Microscopic examination showed a large quantity of carbon particulate debris. The authors have operated on approximately 100 patients so far and no other carbon cage has broken, to their knowledge. CONCLUSIONS: Carbon cages can break if a nonunion occurs and as a result free carbon particles move out to the spinal canal.     

Late radiographic findings after anterior cervical fusion for spondylotic myeloradiculopathy

A retrospective study was performed to evaluate the radiographic changes that occurred at spinal levels adjacent to fused vertebrae after anterior cervical fusion. One hundred six patients with cervical spondylotic myeloradiculopathy (88 men, 18 women) were followed for an average of 8.5 years. The average age at follow-up was 64 years. Forty-two patients underwent a single-level fusion, 52 had a two-level fusion, and 12 had three levels fused. Seventeen patients who underwent additional surgery after anterior fusion also were reviewed, with an average follow-up period of 2.9 years. Postoperatively, cervical flexion-extension resulted in significantly increased movement about the vertebral interspace at the upper adjacent level. An increment of posterior slip of the vertebra immediately above the fusion level, with associated spinal canal compromise of less than 12 mm, significantly affected neurologic results. Patients with multilevel fusions notably exhibited these radiographic abnormalities at adjacent levels. Spinal canal stenosis, when associated with dynamic spinal canal stenosis in the vertebra above the fusion level, affected late neurologic results. Results of salvage laminoplasty were not satisfactory. Unnecessarily extended longer fusion must be avoided.     

A prospective and consecutive study of surgically treated lumbar spinal stenosis. Part I: Clinical features related to radiographic findings

STUDY DESIGN: A prospective and consecutive study of surgical results obtained during serial follow-up investigations in patients who underwent surgery for central lumbar spinal stenosis. OBJECTIVES: To evaluate the result after surgical decompression for lumbar spinal stenosis, at regular intervals after surgery, and to correlate these results with values for preoperative parameters; special interest was focused on the results in relation to the degree of constriction of the spinal canal. SUMMARY OF BACKGROUND DATA: The outcome after surgery for spinal stenosis is debatable; long-term follow-up investigations have indicated deterioration with passing time. Results of studies in nonsurgical patients have demonstrated that the symptoms do not progress with time. Results of a meta-analysis of the literature on surgical results have demonstrated a wide variation of outcomes. MATERIAL AND METHODS: In a prospective study, 105 consecutive patients who underwent surgical decompression (laminectomy with facet-preserving technique, but no fusion) were evaluated at follow-up examinations 4 months and 1, 2, and 5 years after surgery. At the follow-up examinations, the patient's opinion on the surgical result was registered, using a four-grade scale. The occurrence of pain at rest and at night was registered, as well as the patient's walking ability. Statistical analysis was performed, relating the surgical results to patient age, gender, preoperative duration of symptoms and radiographically observed constriction as described in Part I of this study. The radiologist was blinded to patient outcome. Logistic regression analysis was performed. RESULTS: During the follow-up period, 19 patients underwent reoperation, consisting of fusion to treat lumbar pain (n = 4), repeat decompression because of progressive stenosis (n = 13), and repairs in response to surgical complications (n = 2). Follow-up results: The result, related to the recurrence of leg symptoms, deteriorated with passing time. Excellent results were reported by 63% to 67% at 4-month and 2-year follow-ups compared with 52% at the 5-year follow-up. There was a correlation between the constriction of the spinal canal and the outcome at all intervals. Patients with an anteroposterior diameter of 6 mm or less at the narrowest site had significantly better results. The logistic regression analysis demonstrated a significant correlation between a severe reduction of the anteroposterior diameter and excellent results and a tendency toward better results in patients with a shorter preoperative duration of symptoms. Improvement of walking ability was also associated with a pronounced constriction of the spinal canal. CONCLUSION: The results after surgical decompression in patients with central spinal stenosis deteriorated with time. There was a significant correlation between good result and pronounced constriction of the spinal canal. Patients with a preoperative duration of symptoms of less than 4 years and patients with no preoperative back pain tended to have better surgical outcomes. The reoperation rate was 18% within 5 years. When surgery for spinal stenosis is contemplated, these prognostic factors should be taken into consideration: The "ideal patient" has a pronounced constriction of the spinal canal, insignificant lower back pain, no concomitant disease affecting walking ability, and a symptom duration of less than 4 years.