Brucellar spondylitis: a rare cause of spinal cord compression

STUDY DESIGN

A case report.

OBJECTIVES

To present and discuss some of the difficulties in the diagnosis of brucellar spondylitis.

SETTING

Ankara University, Ibni Sina Hospital, Turkey.

METHODS

We report a patient with paraplegia, misdiagnosed as having a malignancy or tuberculosis who actually suffered from brucellar spondylitis. Diagnosis was established by her history and a compatible clinical picture together with a standard tube agglutination (Wright test) titer of > or =1/160 of antibodies for brucellosis. The patient was treated with oral doxycycline, rifampicin, and ciprofloxacin combination.

RESULTS

At the end of the treatment, the blood Brucella Wright and anti-human globulin T titer levels decreased. Her lower limb weakness improved. She could walk, and climb stairs with the help of a cane. Urinary retention and fecal incontinence also resolved.

CONCLUSION

Brucellosis is a systemic infection involving the musculoskeletal and nervous systems. Spondylitis frequently occurs in elderly patients. An early diagnosis of brucellar spondylitis can often be difficult. In endemic regions, as in the case of our country, brucellar spondylitis should always be considered in the differential diagnosis of older patients with back pain and constitutional symptoms. An early diagnosis will help to prevent the development of more severe complications such as spinal cord compression.

One-stage anterior interbody autografting and instrumentation in primary surgical management of thoracolumbar spinal tuberculosis

There are few articles in the literature concerning anterior instrumentation in the surgical management of spinal tuberculosis in the exudative stage. So we report here 23 cases of active thoracolumbar spinal tuberculosis treated by one-stage anterior interbody autografting and instrumentation to verify the importance of early reconstruction of spinal stability and to evaluate the results of one-stage interbody autografting and anterior instrumentation in the surgical management of the exudative stage of throracolumbar spinal tuberculosis. Twenty-three patients, including two children (9 and 15 years old, respectively) and 21 adults with thoracolumbar spinal tuberculosis were treated surgically. T9 to L4 spinal segments were affected, and MRI/CT showed evident collapse of the vertebrae because of tuberculous destruction and paravertebral abscess. Neurological deficits were found in 15 patients. Before surgery, patients received standard anti-tuberculosis chemotherapy for 2 to 3 weeks. Under general endotracheal anaesthesia, the patients were placed in right recumbent positions, and a transthoracic, lateral extracavitary or extrapleural approach was chosen according to the tuberculosis lesion segment. After exposure, the tuberculous lesion region, including the collapsed vertebrae and in-between intervertebral disc, was almost completely resected in order to release the segmental spinal cord. Then, autologous iliac, rib or fibular graft was harvested to complete interbody fusion, and an anterior titanium-alloy plate-screw system was used to reconstruct the stability of the affected segments. Anti-tuberculosis chemotherapy was continued for at least 9 months, and the patients were supported with thoracolumbosacral orthosis for 6 months after surgery. All patients were followed up for an average of 2 years. All 23 cases were healed without chronic sinus formation or any recurrence of tuberculosis during the follow-up period. Spinal fusion occurred at a mean of 3.8 months after surgery. Of all patients with neurological deficits, 14 patients showed obvious improvement; only one patient with Frankel C lesion remained unchanged, but none of the patients got worse. During the follow-up period, a mean of 18 degrees of kyphosis correction was achieved after surgery in the adult group. Moderate progressive kyphosis because of this procedure fusion occurred postoperatively in a 9-year-old child after 2 1/2 years; another 15-year-old child did not demonstrate this phenomenon. Except for the early loosening of one screw in two cases (which did not affect the reconstruction of spinal stability), no other complications associated with this procedure were found during follow-up. Early reconstruction of spinal stability plays an important role in the surgical management of spinal tuberculosis. One-stage anterior interbody autografting and instrumentation in the surgical management of the exudative stage of spinal tuberculosis show more advantages in selected patients, but supplementary posterior fusion should be considered to prevent postoperative kyphosis when this procedure is performed in children.

Behçet's disease and late progressive myelopathy in a patient with severe kyphotic deformity following childhood spinal trauma: is there any connection?

A highly unusual case is presented of a patient affected by Behçet's disease and severe kyphosis in the thoracic spine, who had a history of traumatic spinal cord injury during childhood. A review of the literature is also presented. Magnetic resonance imaging showed spinal cord compression at the level of the apex of the kyphosis in the upper thoracic spine. Although there is no information indicating that the coexistence of post-traumatic spinal deformity with Behçet's disease is not just a coincidental finding, the possibility that it was the presence of Behçet's disease concomitant with the antecedent spinal trauma that may have triggered the severe kyphotic deformity cannot be ruled out.

Titanium cages in the surgical treatment of severe vertebral osteomyelitis

The role of spinal implants in the presence of infection is critically discussed. In this study 20 patients with destructive vertebral osteomyelitis were surgically treated with one-stage posterior instrumentation and fusion and anterior debridement, decompression and anterior column reconstruction using an expandable titanium cage filled with morsellised autologous bone graft. The patients' records and radiographs were retrospectively analysed and follow-up clinical and radiographic data obtained. At a mean follow-up of 23 months (range 12-56 months) all cages were radiographically fused and all infections eradicated. There were no cases of cage dislocation, migration or subsidence. Local kyphosis was corrected from 9.2 degrees (range -20 degrees to 64 degrees ) by 9.4 degrees to -0.2 degrees (range -32 degrees to 40 degrees ) postoperatively and lost 0.9 degrees during follow-up. All five patients with preoperative neurological deficits improved to Frankel score D or E. Patient-perceived disability caused by back pain averaged 7.9 (range 0-22) in the Roland-Morris score at follow-up. In cases of vertebral osteomyelitis with severe anterior column destruction the use of titanium cages in combination with posterior instrumentation is effective and safe and offers a good alternative to structural bone grafts. Further follow-up is necessary to confirm these early results.

[Age and constitutional features in the forming of posture in children 7 to 14 years of age]

Longitudinal study of forming of the posture was performed in 138 healthy pupils of Moscow school No. 710 aged from 6.5 to 14 of both sexes. Simultaneously children were examined anthropometrically and their constitution was determined after Schtefko. The posture was examined visually. It was established that posture forms within observation terms depending on sex, age and somatotype. Peak age for the risk of posture disturbance is 9-11 for girls and 10-12 for boys. Digestive and muscular somatotypes provide favourable prognosis respective to posture (in girls), while astenoid somatotype is the worst. Special type of posture defect is characteristic for each somatotype. In children with digestive and muscular somatotype primary posture defects disappear by 12-14. In children with astenoid and thoracal somatotype their number, in contrary, grows.

Predictive factors for the outcome of anterior cervical decompression and fusion

In a prospective study, 103 patients were randomised to anterior cervical decompression and fusion (ACDF) with a cervical carbon-fibre intervertebral fusion cage or the Cloward procedure. Preoperative background variables, active range of neck motion, handgrip strength, radiological evaluation and subjective variables were used in a multiple regression model to find the strongest predictors of postoperative outcome as measured by current pain intensity and the Neck Disability Index (NDI). Male sex, greater kyphosis at the level operated on, non-smoking, a greater neck mobility in right rotation, low disability on NDI, and older age were predictors of pain reduction and explained 30% of current pain intensity at follow-up. Higher educational level, non-smoking, greater kyphosis at the level operated on, a greater flexion mobility, greater right handgrip strength and lower current pain intensity were predictors of improvement, and explained 28% of the postoperative outcome on NDI. The most important predictor for postoperative pain intensity was the magnitude of the preoperative kyphosis. Preoperative pain intensity was the most important predictor for improved NDI. At follow-up about 70% of the patients still had deficit based on current pain intensity and NDI, and 44% had remaining dysfunction based on Odom's criteria. In conclusion, the multivariate analysis shows that male sex, non-smoking, greater segmental kyphosis and a low pain and disability level are preoperative predictors of a good outcome in ACDF. In addition, the study suggests the importance of other predictive variables than those studied for the outcome of ACDF.

Height of girls with adolescent idiopathic scoliosis

In a Finnish population, the standing height of 1500 consecutive female patients aged 9-24 years (mean 13.9 years) with untreated idiopathic scoliosis of at least 10 degrees in their lateral curves was compared with the standing height of average girls. The mean magnitude of the major curves was 29.4 degrees (range 10 degrees-80 degrees), and that of the minor curves 20.3 degrees (range 0 degrees-66 degrees). A formula for the height loss caused by the lateral curves, and that caused by thoracic kyphosis, was derived. The corrected height of the girls with idiopathic scoliosis was highly significantly (P<0.001) greater than the height of average girls at the age of 11-15, and this high level of significance was present at the age of 11-13, even without correcting for the height loss caused by scoliosis. After maturation, the girls with idiopathic scoliosis were not significantly taller than average girls. On average, the magnitude of thoracic kyphosis did not affect the height of patients with scoliosis as compared with the height of normal girls of the same age.

A neurofibromatosis type 1 patient with severe kyphoscoliosis and intrathoracic meningocele

The patient presented with neurofibromatosis and a dystrophic kyphoscoliosis around the cervico-thoracic junction. When the patient was 59 years old, he started to suffer from dyspnea caused by an intrathoracic meningocele in the upper left thoracic cavity. A wide laminectomy from T2 to T5 was performed and the meningocele was resected. Although the dyspnoea disappeared postoperatively, the patient started to neurologically deteriorate. Laminectomy alone caused instability around the apex of the kyphosoliosis and spinal cord compression. Halo cast was applied and brought remarkable recovery of neurologic deficits. This result encouraged us to perform posterior fusion in situ from C3 to L2 with bone graft from the iliac crests and the Luque technique in conjunction with the Isola system. This resulted in the patient being able to walk again. The removal of the posterior element predisposes the patient to unstable postlaminectomy kyphosis and removes valuable bone stock required for posterior spinal fusion. For this reason, spinal fusion should have been conducted during surgery for the patient's meningocele.

Prediction of osteoporotic spinal deformity

STUDY DESIGN

A biomechanical model was developed from full-spine lateral radiographs to predict osteoporotic spinal deformity in elderly subjects.

OBJECTIVE

To investigate the biomechanics of age-related spinal deformity and concomitant height loss associated with vertebral osteoporosis.

SUMMARY OF BACKGROUND DATA

Vertebral bone loss and disc degeneration associated with aging causes bone and disc structures to weaken and deform as a result of gravity and postural stresses.

METHODS

An anatomically accurate sagittal-plane, upright-posture biomechanical model of the anterior spinal column (C2-S1) was created by digitizing lateral full-spine radiographs of 20 human subjects with a mean height of 176.8 cm and a mean body weight of 76.6 kg. Body weight loads were applied to the model, after which intervertebral disc and vertebral body forces and deformation were computed and the new spine geometry was calculated. The strength and stiffness of the vertebral bodies were reduced according to an osteopenic aging model and modulus reduction algorithm, respectively.

RESULTS

The most osteopenic model (L3 F(ult) = 750 N) produced gross deformities of the spine, including anterior wedge-like fracture deformities at T7 and T8. In this model, increases in thoracic kyphosis and decreases in vertebral body height resulted in a 25.2% decrease in spinal height (C2-S1), an 8.6% decrease in total body height, and a 15.1-cm anterior translation of the C2 spine segment centroid. The resulting deformity qualitatively resembled deformities observed in elderly individuals with osteoporotic compression fractures.

CONCLUSIONS

These predictions suggest that postural forces are responsible for initiation of osteoporotic spinal deformity in elderly subjects. Vertebral deformities are exacerbated by anterior translation of the upper spinal column, which increases compressive loads in the thoracolumbar region of the spine.

Do alterations in vertebral and disc dimensions affect an elliptical model of thoracic kyphosis?

STUDY DESIGN

Mathematical modeling, using least squares method, of thoracic kyphosis was constructed as digitized points from radiographs of 50 healthy patients.

OBJECTIVE

To determine a simple geometric model of the thoracic kyphosis.

SUMMARY OF BACKGROUND DATA

Thoracic kyphosis is an important parameter of health, but geometric models of kyphosis are rare. Few papers report vertebral body and disc height data.

METHODS

Thoracic vertebral bodies were digitized on lateral radiographs of 50 healthy patients. The average path of the posterior vertebral body corners of T1 through T12 was modeled, in the least squares sense, with a portion of an ellipse. The best-fit ellipse was sectioned with different model partitions using four sets of vertebral body heights and disc heights. Segmental and global angles derived from these four models were compared with reported values in the literature.

RESULTS

A 72 degrees portion of an ellipse, with a minor-to-major axis ratio of 0.69, can closely approximate the path of the posterior body corners from the inferior of T1 to the superior of T12. The posterior vertebral body heights and disc heights have an average ratio of approximately 5:1. Segmental angles from T3-T4 through T11-T12 for all four models are close to other reported values. The thoracic spine has a height-to-length ratio of approximately 0.96.

CONCLUSIONS

Thoracic kyphosis from inferior-posterior T1 to superior-posterior T12 can be closely modeled (least squares error per point < 1 mm) with a 72 degrees piece of an ellipse with a minor-to-major axis ratio of 0.69. The major axis is parallel to the posterior body margin of T12, whereas the minor axis passes through the superior endplate of T12. Segmental angles derived from this elliptical modeling are in the range of values from healthy patients.

Sagittal profile of the elderly

Little is known about the natural history of spinal alignment as it ages into the eighth and ninth decades. Fifty asymptomatic volunteers 70-85 years of age (mean 76 years) without any history of spine pain, trauma, or deformity were radiographed in the standing lateral position, from C7 to the pelvis including the hips. Measurements included segmental angulations, kyphosis, lordosis, and C7 plumb line balance. In addition, measurements of sagittal pelvic balance were made (pelvic incidence, tilting, sacral slope, and S1 overhang). Average kyphosis was 52 degrees (range 29 degrees to 79 degrees); the average lordosis was -57 degrees (range -96 degrees to -20 degrees). The C7 plumb line on average fell 40 mm anterior to the posterosuperior corner of S1. The anterior positioning of C7 was also positively correlated with age and decreasing lordosis. This provides further data into the natural history of the aging spine.

Severe pathologic compression of three consecutive vertebrae in Gaucher's disease: a case report and review of the literature

To date, only one patient with spinal affection of Gaucher's disease requiring surgery for spinal compression has been reported. We present an additional case with extensive affection of three consecutive vertebral bodies, and present a review of the literature relating to the management of therapy and follow-up of this disease.

[Subsidence and its effect on the anterior plate stabilization in the course of cervical spondylodesis. Part I: definition and review of literature]

A definition of subsidence in terms of spinal biomechanics is presented in the paper. Subsidence is defined as sinking of a body with a higher elasticity modulus (e.g. graft, cage, spacer) in a body characterized by a lower elasticity modulus (e.g. vertebral body), resulting in 3D changes of the spinal geometry. Magnitude of subsidence is directly proportional to the load pressure and to the difference between the elasticity modules, but inversely proportional to the area of the graft-bed interface. Both biological and mechanical qualities of the graft-bed interface are important for the subsidence process. Any excessive subsidence decreases the interbody space and produces both local and general kyphotization of the spine. This may cause destabilization of the screw-plate and/or screw-bone interfaces (e.g. pulling-out, altered angulation or breakage of the screws). A method is proposed of radiological estimating the absolute magnitude of subsidence, based on the real known length of the implanted stabilizer (e.g. plate). Clinical examples of an excessive subsidence and its impact on the stabilizing plate system are presented. Subsidence is inherent in the interbody fusion process. Endplate preservation and a dynamic modification of cervical plates may enables us to control subsidence and reduce the number of complications.

Percutaneous vertebroplasty and kyphoplasty for painful vertebral body fractures in cancer patients

OBJECT

The current North American experience with minimally invasive vertebro- and kyphoplasty is largely limited to the treatment of benign osteoporotic compression fractures. The objective of this study was to assess the safety and efficacy of these procedures for painful vertebral body (VB) fractures in cancer patients.

METHODS

The authors reviewed a consecutive group of cancer patients (21 with myeloma and 35 with other primary malignancies) undergoing vertebro- and kyphoplasty at their institution. Ninety-seven (65 vertebro- and 32 kyphoplasty) procedures were performed in 56 patients during 58 treatment sessions. The mean patient age was 62 years (+/- 13 years [standard deviation]) and the median duration of symptoms was 3.2 months. All patients suffered intractable spinal pain secondary to VB fractures. Patients noted marked or complete pain relief after 49 procedures (84%), and no change after five procedures (9%); early postoperative Visual Analog Scale (VAS) pain scores were unavailable in four patients (7%). No patient was worse after treatment. Reductions in VAS pain scores remained significant up to 1 year (p = 0.02, Wilcoxon signed-rank test). Analgesic consumption was reduced at 1 month (p = 0.03, Wilcoxon signed-rank test). Median follow-up length was 4.5 months (range 1 day-19.7 months). Asymptomatic cement leakage occurred during vertebroplasty at six (9.2%) of 65 levels; no cement extravasation was seen during kyphoplasty. There were no deaths or complications related to the procedures. The mean percentage of restored VB height by kyphoplasty was 42 +/- 21%.

CONCLUSIONS

Percutaneous vertebro- and kyphoplasty provided significant pain relief in a high percentage of patients, and this appeared durable over time. The absence of cement leakage-related complications may reflect the use of 1) high-viscosity cement; 2) kyphoplasty in selected cases; and 3) relatively small volume injection. Precise indications for these techniques are evolving; however, they are safe and feasible in well-selected patients with refractory spinal pain due to myeloma bone disease or metastases.

Ventral correction of postsurgical cervical kyphosis

OBJECT

Cervical kyphotic deformation may develop after surgery involving either the ventral or dorsal approach. Regardless of the cause, the development of a cervical kyphotic deformity should be avoided, if possible, and corrected if present, when appropriate. The authors describe their experience with a technique for the ventral correction of iatrogenic (postoperative) cervical kyphosis.

METHODS

A retrospective review of cases involving correction of postoperative iatrogenic cervical kyphosis via an ventral approach was performed. The authors conducted an ventral approach to kyphosis correction. The procedure required specific head positioning (in extension), convergent distraction pins, and an ventrally placed implant (axially dynamic when appropriate) with multiple points of fixation including at least one point of intermediate fixation. The pre- and postoperative sagittal angle and clinical status were evaluated. During a nearly 14-month period, 12 patients met the inclusion criteria. Ten patients underwent a minimum of 6 months of follow up. They comprised the study population. Most patients presented with mechanical neck pain as part of their symptom profile. The mean magnitude of deformity correction (pre- to postoperative) was 20 degrees of lordosis. The mean postoperative sagittal angle was 6 degrees of lordosis. The mean change in the sagittal angle during the follow-up period was 2.2 degrees of lordosis.

CONCLUSIONS

The ventral approach to correction of cervical deformity led to the achievement of lordosis in all but one patient. This posture was effectively maintained during the follow-up period. All patients exhibited improvement postoperatively; three experienced complete resolution of their preoperative symptoms. When symptoms are related to postsurgical kyphosis, deformity correction should be considered. Such a procedure may be performed effectively via an ventral approach in most circumstances.

Maximal bite force and its associations with spinal posture and craniofacial morphology in young adults

Maximal bite force (MBF) and its associations with craniofacial morphology and spinal posture were studied in a group of young adults (46 M and 38 F) aged 21 to 23 years. MBF was recorded in molar and incisal regions. Sagittal spinal posture was measured by spinal pantography and trunk asymmetry at thoracic and lumbar levels by a forward-bending test. Craniofacial variables and posture of the cervical spine were examined from lateral cephalograms taken in a natural head position. No statistically significant correlations existed between MBF and spinal posture, but significant correlations did exist between MBF and craniofacial variables, especially in women.

Tuberculosis of the spine (Pott's disease) presenting as 'compression fractures'

STUDY DESIGN

Case reports and survey of literature.

OBJECTIVE

Case reports of two women with tuberculosis (TB) of the spine (Pott's disease) presenting with severe back pain and diagnosed as compression fracture are described. Physicians should include Pott's disease in the differential diagnosis when patients present with severe back pain and evidence of vertebral collapse.

SETTING

Ohio, USA METHODS: A review of the literature on the pathogenesis, pathophysiology, clinical presentation, diagnostic methods, treatment and prognosis of spinal TB was conducted.

RESULTS

After initial delay, proper diagnosis of spinal TB was made in our patients. Microbiologic diagnosis confirmed M. tuberculosis, and appropriate medical treatment was initiated.

CONCLUSIONS

Although uncommon, spinal TB still occurs in patients from developed countries, such as the US and Europe. Back pain is an important symptom. Vertebral collapse from TB may be misinterpreted as 'compression fractures' especially in elderly women. Magnetic resonance imaging scan (MRI) is an excellent procedure for the diagnosis of TB spine. However, microbiologic diagnosis is essential. Mycobacterium tuberculosis may be cultured from other sites. Otherwise, biopsy of the spine lesion should be done for pathologic diagnosis, culture and stain for M. tuberculosis. Clinicians should consider Pott's disease in the differential diagnosis of patients with back pain and destructive vertebral lesions. Proper diagnosis and anti-tuberculosis treatment with or without surgery will result in cure.

A Schinzel-Giedion-like syndrome--a milder version or a separate condition?

We report two 12-year-old monozygotic twins followed from birth. Their features include midface hypoplasia, a prominent forehead, coarse features, sensorineural deafness, short stature with thoracic kyphosis and lumbar lordosis and intellectual delay. As they have developed, their features have been reminiscent of a storage disorder but mucopolysaccharidoses, mucolipidoses and gangliosidoses have been excluded by biochemical testing. We discuss the phenotypic overlap with the Schinzel-Giedion syndrome but highlight the important differences. Individuals with Schinzel-Giedion syndrome tend to have renal and cardiac malformations and to have a very poor outlook, often dying in the first 3 years of life. We suggest that these twins have a previously undescribed Schinzel-Giedion like syndrome.

Spinal deformities in farmed Atlantic salmon

Spinal deformities in farmed Atlantic salmon (Salmo salar) are often observed in intensive farming systems and result in production losses. Many putative factors have been implicated with the formation of spinal deformities in larger salmon. This condition has been described as broken back syndrome, curvy back disease, and short tails.

Fate of the transpedicular intervertebral bone graft after posterior stabilisation of thoracolumbar fractures

The authors present a retrospective clinical and radiological study addressing the outcome after posterior stabilisation of thoracolumbar fractures with intervertebral fusion via transpedicular bone grafting. The study included computed tomographic (CT) scan after implant removal for analysis of the intervertebral fusion and incorporation of the intervertebral bone graft and its influence on postoperative re-kyphosing. Twenty-nine patients with acute fractures of the thoracolumbar spine, treated between 1988 and 1995 at the Department of Trauma Surgery, Hannover Medical School, underwent posterior stabilisation and interbody fusion with transpedicular cancellous bone grafting. This study group was followed clinically and radiologically for a mean of 3.5 years. All patients underwent spiral CT scan with sagittal reconstruction after implant removal. Twenty-four type A, four type B, and one type C lesion were posteriorly stabilised and transpedicular intervertebral bone grafting was performed. The operative time averaged 2 h 50 min, the intraoperative fluoroscopy time 4 min 7 s, and the mean intraoperative blood loss was 376 ml. Four patients out of six with an incomplete neurologic lesion (Frankel/ASIA D) improved to Frankel/ASIA grade E. Two complications were observed: one delayed wound healing and one venous thrombosis with secondary pulmonary embolism. Compared to the preoperative status, our follow-up examinations demonstrated permanent social sequelae: the percentage of individuals able to do physical labor was reduced, whereas the proportion of unemployed or retired patients increased. The assessment of complaints and functional outcome with the Hannover Spine Score reflected a significant difference ( P<0.001) between the status before injury (96.6/100 points) and at follow-up (64.4/100 points). The radiographic follow-up revealed a mean loss of correction of 7.8 degrees ( P<0.005). CT scans after implant removal showed an interbody fusion and incorporation of the transpedicular bone graft in ten patients (34%). In another ten patients (34%), the CT scans demonstrated the interbody fusion at the anterior and posterior walls of the vertebral body via direct contact due to collapse of the disc space. In these patients, the bone graft was not incorporated and no central interbody fusion could be found. In nine patients (31%) neither interbody fusion nor incorporation of the transpedicular graft was achieved. A frequent and reliable intervertebral fusion could not be achieved with the described technique of transpedicular bone grafting. The ineffectiveness of the intervertebral graft was found to be a reason for postoperative re-kyphosing.

Can the thoracic kyphosis be modeled with a simple geometric shape? The results of circular and elliptical modeling in 80 asymptomatic patients

Many Cobb measurements have been reported at various levels for the thoracic kyphosis, but geometric models of the shape of kyphosis are rare. Thoracic vertebral bodies were digitized on 80 normal lateral full-spine radiographs to obtain the mean thoracic kyphosis. Global and segmental angles were determined. Computer iteration processes passed geometric shapes through the posterior body coordinates of the mean thoracic kyphosis to determine the best fit model in the least squares sense. The kyphosis was closely modeled with ellipses. The T1 and T12 areas tended to be flatter in curvature when compared with T2-T11, indicating these are inflection points. Mean global angles were Cobb(T1-T12) = 44.2 degrees, Cobb(T2-T11) = 39.9 degrees, and Cobb(T3-T10) = 33.3 degrees. The T2-T11 kyphotic region was closely modeled with approximately a 70-degree portion of an ellipse, with minor axis to major axis ratios of 0.6 to 0.72, and with major axis parallel to the posterior body margin of T11.

Premature aging in mice deficient in DNA repair and transcription

One of the factors postulated to drive the aging process is the accumulation of DNA damage. Here, we provide strong support for this hypothesis by describing studies of mice with a mutation in XPD, a gene encoding a DNA helicase that functions in both repair and transcription and that is mutated in the human disorder trichothiodystrophy (TTD). TTD mice were found to exhibit many symptoms of premature aging, including osteoporosis and kyphosis, osteosclerosis, early greying, cachexia, infertility, and reduced life-span. TTD mice carrying an additional mutation in XPA, which enhances the DNA repair defect, showed a greatly accelerated aging phenotype, which correlated with an increased cellular sensitivity to oxidative DNA damage. We hypothesize that aging in TTD mice is caused by unrepaired DNA damage that compromises transcription, leading to functional inactivation of critical genes and enhanced apoptosis.

Cranial base kyphosis and the surface morphology of the anterior cranial fossa

We investigated the relationship between the surface morphology of the anterior cranial fossa and cranial base kyphosis (sphenoid angle) in 52 cephalometric craniograms. Among them there were 25 female (mean age 54 +/- 15; range 31-82) and 27 male (mean age 43 +/- 18, range 19-85) skulls. The sphenoid angle and the altitudes of the highest elevation of the endofrontal eminence (cranial base over the orbital roof in the anterior cranial fossa) and the middle point of the sphenoid planum, measured according to the Frankfort horizontal, were analysed using classical cephalometric and morphometric analysis. Statistical analysis was performed by Pearson's product-moment correlation and simple linear regression. The sphenoid angle ranged from 97 degrees to 137 degrees (mean 118 +/- 9 degrees). The altitude ratio of the highest elevation of the endofrontal eminence and the middle point of the sphenoid planum ranged from 1.5 to 1.8 (mean 1.6 +/- 0.1). A significant correlation was found between this ratio and the sphenoid angle (r = -0.65; p < 0.001; coefficient of determination = 0.43). The elevation of the endofrontal eminence relative to the sphenoid planum was higher in skulls with increased cranial base kyphosis, whereas reduced sphenoid angle was associated with an increase in the elevations of the endofrontal eminence. Although the sphenoid angle has a significant effect on the morphology of the anterior cranial fossa, only 43% of the variance in altitude of the endofrontal eminence is likely to be explained by its relationship with the sphenoid angle.

[Decreased bone mineral density as a risk factor in the development of spinal deformities in neurofibromatosis]

Neurofibromatosis-1 is a here-do-familiar disorder that is associated with a variety of skeletal anomalies, mostly with spinal deformities in 10-50% of the patients. Intraoperatively, a poor vertebral bone quality has been observed. Efforts have been made to identify factors preventing curve progression, to optimize operational planning and to explain the pathomechanism. As part of the preoperative evaluation, the authors used a dual X-ray absorptiometry to assess the bone mineral density of the lumbar spine in 12 non operated patients with neurofibromatosis-1, supplemented by laboratory blood/urine investigations. A significant decrease in bone mineral density of lumbar spine was measured. An inverse relation was suggested between the severity of scoliosis and the lumbar spine Z-scores. No pivotal alterations were identified in the laboratory measurements. The bony tissue abnormality observed intraoperatively in neurofibromatosis-1 patients may be described as a diminution of the axial bone mineral density. The evaluation of bone mineral density in the course of the preoperative planning is proposed in neurofibromatosis-1.

Mice with a targeted deletion of the tetranectin gene exhibit a spinal deformity

Tetranectin is a plasminogen-binding, homotrimeric protein belonging to the C-type lectin family of proteins. Tetranectin has been suggested to play a role in tissue remodeling, due to its ability to stimulate plasminogen activation and its expression in developing tissues such as developing bone and muscle. To test the functional role of tetranectin directly, we have generated mice with a targeted disruption of the gene. We report that the tetranectin-deficient mice exhibit kyphosis, a type of spinal deformity characterized by an increased curvature of the thoracic spine. The kyphotic angles were measured on radiographs. In 6-month-old normal mice (n = 27), the thoracic angle was 73 degrees +/- 2 degrees, while in tetranectin-deficient 6-month-old mice (n = 35), it was 93 degrees +/- 2 degrees (P < 0.0001). In approximately one-third of the mutant mice, X-ray analysis revealed structural changes in the morphology of the vertebrae. Histological analysis of the spines of these mice revealed an apparently asymmetric development of the growth plate and of the intervertebral disks of the vertebrae. In the most advanced cases, the growth plates appeared disorganized and irregular, with the disk material protruding through the growth plate. Tetranectin-null mice had a normal peak bone mass density and were not more susceptible to ovariectomy-induced osteoporosis than were their littermates as determined by dual-emission X-ray absorptiometry scanning. These results demonstrate that tetranectin plays a role in tissue growth and remodeling. The tetranectin-deficient mouse is the first mouse model that resembles common human kyphotic disorders, which affect up to 8% of the population.

Spinal lordosis with marked opisthotonus secondary to dystonia musculorum deformans: case report with surgical management

STUDY DESIGN

A case report of severe spinal lordosis with marked opisthotonus and retrocollis secondary to dystonia musculorum deformans is presented.

OBJECTIVE

To describe a case of dystonia musculorum deformans with progressive spinal lordosis and its surgical treatment.

SUMMARY OF BACKGROUND DATA

Four patients with correction of coronal spinal deformity associated with dystonia musculorum deformans have been reported in the literature. No reports of sagittal spinal deformity treated with surgical instrumentation and fusion were found.

METHODS

A retrospective chart and radiographic review of a single case was conducted.

RESULTS

Orthotic management and pharmacologic therapy with botulinum toxin injections were unsuccessful in controlling the deformity. Severe spinal lordosis (170 degrees ) from occiput to sacrum was corrected surgically, allowing an upright posture.

CONCLUSION

Dystonia musculorum deformans is a rare condition resulting in coronal or sagittal plane deformities. When other treatment methods are unsuccessful, surgical instrumentation and arthrodesis may correct the deformity and improve function.

A newly recognized syndrome of skeletal dysplasia with opalescent and rootless teeth

A Thai girl with skeletal dysplasia and dental anomalies was seen. Her anomalies consisted of disproportionately short stature, short neck, broad and depressed nasal bridge, broad chest in the anteroposterior dimension, kyphosis, widely spaced nipples, and protruded abdomen. Radiographic testing indicated that she had a large sella turcica, platyspondyly, hypoplastic acetabulum, and a small body of mandible. Both her deciduous and permanent teeth were equally opalescent, and most were rootless, with root development of the mandibular teeth more severely affected. Some maxillary roots were extremely short and tapered. Hypodontia was also observed. These findings represent a unique and hitherto undescribed syndrome of skeletal dysplasia with concomitant dental anomalies.

Transpedicular wedge osteotomy for correction of thoracolumbar kyphosis in ankylosing spondylitis: experience with 78 patients

STUDY DESIGN

This is a retrospective study of surgical correction of thoracolumbar kyphosis caused by ankylosing spondylitis.

OBJECTIVE

To report the surgical results of thoracolumbar kyphosis deformity corrected with transpedicular wedge osteotomy performed by a single surgeon at a university hospital.

SUMMARY OF BACKGROUND DATA

There has not been a large series in the literature reporting on results of the Thomasen-type closing wedge osteotomy for correction of kyphosis deformity secondary to ankylosing spondylitis, nor has two-level osteotomy of this type in one patient ever been described.

METHODS

From 1991 through 1998, 92 transpedicular wedge osteotomies were performed in 78 patients with ankylosing spondylitis for correction of fixed flexion deformity of the thoracolumbar spine.

RESULTS

The mean amount of correction for each level of osteotomy was 34.5 degrees (range, 15 degrees -60 degrees ). The largest amount of overall correction for a single patient was 100 degrees. Most of the osteotomies (64 of 92) were done at L2 and L3. Fourteen patients with severe deformity required staged two-level osteotomy. Excellent and good results were obtained in 77 patients (98.7%) at the final follow-up. There was no mortality, nor were there any major neurological complications.

CONCLUSIONS

Transpedicular wedge osteotomy can effectively and safely correct kyphotic deformity of the thoracolumbar spine caused by ankylosing spondylitis, regardless of rigidity of the spinal curves. Two-level osteotomy can provide sufficient correction for severe cases.

High prevalence of thoracic vertebral deformities and discal wedging in ankylosing spondylitis patients with hyperkyphosis

OBJECTIVE

To study the prevalence of deformities of vertebrae and intervertebral discs in patients with ankylosing spondylitis (AS) in relation to fixed hyperkyphosis of the spine.

METHODS

Altogether 50 patients (15 women, 35 men) with AS were studied. Hyperkyphosis was measured by the occiput to wall distance (OWD). Anterior (Ha), mid- (Hm), and posterior height (Hp) of the vertebrae and intervertebral discs were measured on lateral radiographs of the thoracic (Th5-Th12) and lumbar spine (L1-L5). Vertebral shapes were analyzed according to McCloskey, et al. Wedging of discs was calculated as Ha/Hp. Hyperkyphosis was defined as OWD > 1 cm.

RESULTS

In the thoracic spine, the prevalence of vertebral deformities was higher in patients with hyperkyphosis (n = 38) compared to patients without hyperkyphosis (n = 12) (45% vs 8%; p = 0.01). The prevalence of thoracic vertebral deformities in patients with hyperkyphosis differed little between men and women (39% vs 58%; p > 0.10) and among patients above and below the age of 45 years (50% vs 33%; p > 0.10). Patients with one or more deformed thoracic vertebrae had a higher mean OWD than patients without deformed vertebrae (12 +/- 7 vs 7 +/- 6 cm; p < 0.01). The total sum of deformities of the thoracic vertebrae and discs explained 43% of the variance of the age adjusted OWD (p < 0.001). Deformities of lumbar vertebrae and discs did not contribute to hyperkyphosis.

CONCLUSION

In patients with AS and hyperkyphosis, deformities of the thoracic vertebrae occur frequently and, together with wedging of the thoracic discs, contribute significantly to fixed hyperkyphosis of the spine.

Efficient transmission of two different sheep scrapie isolates in transgenic mice expressing the ovine PrP gene

We produced transgenic mice expressing the sheep prion protein to obtain a sensitive model for sheep spongiform encephalopathies (scrapie). The complete open reading frame, with alanine, arginine, and glutamine at susceptibility codons 136, 154, and 171, respectively, was inserted downstream from the neuron-specific enolase promoter. A mouse line, Tg(OvPrP4), devoid of the murine PrP gene, was obtained by crossing with PrP knockout mice. Tg(OvPrP4) mice were shown to selectively express sheep PrP in their brains, as demonstrated in mRNA and protein analysis. We showed that these mice were susceptible to infection by sheep scrapie following intracerebral inoculation with two natural sheep scrapie isolates, as demonstrated not only by the occurrence of neurological signs but also by the presence of the spongiform changes and abnormal prion protein accumulation in their brains. Mean times to death of 238 and 290 days were observed with these isolates, but the clinical course of the disease was strikingly different in the two cases. One isolate led to a very early onset of neurological signs which could last for prolonged periods before death. Independently of the incubation periods, some of the mice inoculated with this isolate showed low or undetectable levels of PrPsc, as detected by both Western blotting and immunohistochemistry. The development of experimental scrapie in these mice following inoculation of the scrapie infectious agent further confirms that neuronal expression of the PrP open reading frame alone is sufficient to mediate susceptibility to spongiform encephalopathies. More importantly, these mice provide a new and promising tool for studying the infectious agents in sheep spongiform encephalopathies.

[Validity and reliability of spinal clinical measures in ankylosing spondylitis]

OBJECTIVES

To evaluate the validity and the reliability of the main clinical measures of mobility and sagittal spinal curves in ankylosing spondylitis (AS).

METHODS

Criterion validity of the measure of the distance between C7 spinous process to plumbline (dorsal kyphosis), L3-plumb line (lumbar lordosis), lumbar, dorsolumbar and dorsal mobility. The gold standard was the value obtained from lateral radiological views of the dorsal and lumbar spine in standing position and maximum flexion. The correlation between radiological and clinical measures was assessed by a Spearman correlation coefficient (SCC). The reliability was assessed for all the clinical parameters and for chin-sternum distance (flexion, extension), chin-acromion distance (rotations) and chest expansion using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Were included patients with AS and needing dorsal and lumbar Xrays.

RESULTS

Twenty-two patients (21 men), 32 +/- 11 year old, 51 +/- 10 kg weight, with a mean duration of the disease of 120 +/- 60 months. The ICC values were good or excellent for all parameters except for the measures of dorsal mobility. The validity was evaluated in 18 patients. The value of the SCC between clinical and radiological measures was good except the measures of dorsal kyphosis and dorsal mobility.

CONCLUSION

The clinical measures of mobility and sagittal curves have metrological properties good enough to be used in the monitoring of AS mainly for the follow-up and the evaluation of the rehabilitation. The measurement of dorsal mobility should be restricted to the lower part only. Although apparently not valid the distance C7-plumbline can be used in management of AS because of its excellent reliability.

The effects of hook pattern and kyphotic angulation on mechanical strength and apical rod strain in a long-segment posterior construct using a synthetic model

STUDY DESIGN

Synthetic spine models were used to compare the effects of hook pattern and kyphotic angulation on stiffness and rod strain in long-segment posterior spinal constructs.

OBJECTIVES

To examine the biomechanical effects of hook patterns and kyphotic angulation on long-segment posterior spinal constructs.

SUMMARY OF BACKGROUND DATA

Kyphotic deformities managed by increasing rod diameter and hence construct stiffness have shown decreased postoperative loss of correction and hardware complications. The biomechanical effects of hook pattern and kyphosis are unknown.

METHODS

Spine models of 0 degrees, 27 degrees 54 degrees sagittal contour, composed of polypropylene vertebral blocks and isoprene elastomer intervertebral spacers, representing T3-T12, were used for biomechanical testing of long-segment posterior spinal constructs. Models were instrumented with 6.35-mm titanium rods and one of the following hook configurations: 20-hook compression, 16-hook compression, 16-hook claw apex-empty,16-hook claw apex-full, or 8-hook claw. Construct stiffness and rod strain during axial compression were determined.

RESULTS

The compression-hook patterns provided at least a 45% increase in construct stiffness (P = 0.013)and a 22% decrease in rod strain (P < 0.0001) compared with those obtained with the claw-hook pattern with the best biomechanical performance. When analyzing all five hook patterns, there was a 19% decrease in construct stiffness and 27% increase in rod strain when progressing from straight alignment to 27 degrees of sagittal contour (P < 0.0001). Progressing from straight alignment to 54 degrees decreased construct stiffness by 48% and increased rod strain by 55% (P < 0.0001). Construct stiffness was inversely correlated to rod strain in all five hook patterns (R2 = 0.82-0.98, P < 0.001).

CONCLUSIONS

Using compressive-hook patterns and decreasing the kyphotic deformity significantly increases construct stiffness and decreases rod strain.

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

STUDY DESIGN

Seven patients with angular kyphotic deformity of the thoracic or thoracolumbar spine were treated by closing-opening wedge osteotomy using a single posterior approach.

OBJECTIVES

To examine the safety and efficacy of closing-opening wedge osteotomy for angular kyphosis.

SUMMARY OF BACKGROUND DATA

Correction osteotomy of severe kyphosis is a challenging operation. A two-stage operation has been commonly used: anterior release and decompression followed by posterior correction and fusion.

METHODS

Seven patients with angular kyphosis were treated. The apex level of kyphosis was T5 in one patient, T11 in one, and T12 in five. There was old fracture in five patients, congenital deformity in one, and neurofibromatosis in one. The first 30-35 degrees of kyphosis are corrected using the closing wedge technique with the hinge of the anterior longitudinal ligament after veretebrectomy and circumspinal decompression of the spinal cord. Then the hinge is moved posteriorly to the spinal cord and the remainder of the requisit angle of osteotomy is corrected using the opening-wedge technique (closing-opening wedge osteotomy). Spinal curvature is stabilized using posterior instrumentation and graft.

RESULTS

Localized kyphosis was reduced from an average of 67 degrees to 18 degrees at 2.2 to 7.5 years' follow-up. Sagittal alignment from T1 to the sacrum became more physiologic than before. There were no neurologic complications. Bony fusion was achieved in all patients, and there was no correction loss.

CONCLUSIONS

Satisfactory correction is safely performed by closing-opening wedge osteotomy with a direct visualization of the circumferentially decompressed spinal cord. Although the performance is technically laborious, it offers good correction without jeopardizing the integrity of the spinal cord.

Deformity planning for sagittal plane corrective osteotomies of the spine in ankylosing spondylitis

Ankylosing spondylitis (AS) may lead to a severe fixed thoracolumbar kyphotic deformity (TLKD) of the spine. In a few patients, the TLKD is so extreme that a corrective osteotomy of the spine may be considered. Several authors have reported the results of patients treated by a lumbar osteotomy, but there is no consensus on the level of the osteotomy and on the exact degree of correction required. This can be explained by the lack of quantification of the sagittal plane deformity, since compensation mechanisms of the lower extremities have to be reckoned with for the assessment of spinal sagittal balance in AS. Therefore, there is a need for a method of deformity planning for sagittal plane corrective osteotomies of the spine in AS. In this study, a biomechanical analysis and a newly developed planning procedure are presented and illustrated with two cases of AS. Sagittal balance of the spine was defined in relation to the physiologic sacral end plate angle using trigonometric terms. Nomograms were constructed to show the relationship between the correction angle, horizontal position of the C7 plumb line and the level of the spinal osteotomy. The surgical results of two patients were retrospectively analyzed with our method. It showed that the effect of a spinal osteotomy on the horizontal position of the C7 plumb line depends on the combination of correction angle and the level of osteotomy. In one patient, the achieved correction of the deformity proved to correct the sagittal spinal balance and the pelvic sacral endplate angle. In the other patient, the achieved correction was not sufficient. It is concluded that adequate deformity planning for sagittal plane corrective osteotomies of the spine in AS is essential for reliable prediction of the effect of a lumbar osteotomy on the correction of the spine.

Associations between thoracic kyphosis, head posture, and craniofacial morphology in young adults

The aim of the present study was to investigate associations between thoracic hyper- and hypokyphosis, head posture, and craniofacial morphology in young adults. Using forward bending test and spinal pantographic measurements, 31 subjects, 16 with thoracic hyper- and 15 with hypokyphosis, were selected from a population-based cohort of 430 young adults. Lateral roentgen-cephalograms were taken in natural head posture and craniofacial and postural angular measurements were calculated. Any statistically significant differences between the groups thoracic hyperkyphosis and thoracic hypokyphosis--were analysed using Student's t test. Subjects with thoracic hyperkyphosis had a larger atlantocervical angle (At/ CVT, P < 0.01) than subjects with thoracic hypokyphosis. However, head position (NSL/VER) was similar in both groups, probably owing to the visual perception control of craniovertical relation. There was no statistically significant difference in craniofacial morphologyy between the groups.

Transoral decompression, anterior plate fixation, and posterior wire fusion for irreducible atlantoaxial kyphosis in rheumatoid arthritis

STUDY DESIGN

Fifteen consecutive patients with irreducible atlantoaxial kyphosis caused by rheumatoid arthritis were treated by combined transoral odontoid resection, anterior plate fixation, and posterior wire fusion.

OBJECTIVES

To investigate the clinical results of this new surgical procedure.

SUMMARY AND BACKGROUND DATA

Irreducible atlantoaxial kyphosis in rheumatoid arthritis results from a destruction of the craniocervical joint ligaments and the anterior aspects of the lateral atlantoaxial joints. The development of a paradental synovial pannus and atlantoaxial joint impaction prevents reduction by conservative treatment, such as skull traction. Posterior surgical procedures for the treatment of the irreducible atlantoaxial kyphosis with spinal cord compression have been associated with high morbidity and mortality.

METHODS

Fifteen consecutive patients were treated by transoral odontoid resection. The fixation was performed with anterior plating, according to the method of Harms in combination with posterior wire fusion according to Brooks. Before and after surgery, evaluation was performed using the parameters of pain (visual analog scale), range of motion, and subjective assessment of improvement and the Health Assessment Questionnaire. The neurologic deficit was defined according to the classifications proposed by Ranawat, Frankel, and Nurwick. Plain radiographs, including lateral flexion and extension views, and magnetic resonance scans were obtained.

RESULTS

No perioperative fatality occurred. The average clinical and radiographic follow-up was 50.7 +/- 15.6 months (range, 26-77). Postoperative pain was relieved (mean pain score before surgery, 7.9 +/- 1.87; after surgery, 3.8 +/- 1.27), and the range of motion of all patients increased (mean 21.5 +/- 14.0 degrees for rotation; mean 17.2 +/- 5. 54 degrees for bending). The score on the Health Assessment Questionnaire increased in three patients, remained unchanged in three and decreased in six patients (three had died). All patients improved at least one Ranawat level after surgery, except a patient in Ranawat Class II, whose condition remained unchanged. All patients were satisfied with the procedure and reported subjective improvement.

CONCLUSION

Transoral plate fixation combined with posterior wire fixation after transoral odontoid resectionis an effective, reliable, and safe procedure for the treatment of irreducible atlantoaxial kyphosis in rheumatoid arthritis.

A reliable technique for the assessment of posture: assessment criteria for aspects of posture

BACKGROUND

The purposes of this study were: a) to describe assessment criteria for 10 separate aspects of posture; b) to describe the development and use of a qualitative posture rating scale based on the above; and c) to establish the reliability of the assessment technique.

METHODS

Experimental design. Observation and photographic record of the posture of a sample of adolescent males. Reliability determined using two observations separated by a period of seven days.

PARTICIPANTS

114 adolescent males (age, 15-17 yrs) randomly selected from two post-primary schools.

MEASURES

Ten different aspects of posture assessed according to defined criteria. Assessments made from four photographs: anterior, posterior, lateral and oblique views.

RESULTS

Through examination of the photographs a qualitative postural assessment scale was developed. This consisted of three categories for each aspect of posture, corresponding to: good posture, moderate defect, and severe defect. Definite assessment criteria for each of the 10 aspects of posture have been described. The above has resulted in an assessment procedure in which the reproducibility of the posture scores exceeded 85 % for all aspects assessed.

CONCLUSIONS

Definite criteria for the examination of 10 different aspects of posture have been described and clear diagrams representing good posture, moderate and severe defects have been produced. The reproducibility of the assessment procedure described makes it suitable for investigating the relationships between posture and other health variables such as musculo-skeletal disorders.

A noninvasive anthropometric technique for measuring kyphosis and lordosis: an application for idiopathic scoliosis

STUDY DESIGN

Cross-sectional measurement of the sagittal geometry of adolescent idiopathic scoliosis patients.

OBJECTIVES

To evaluate the accuracy of a noninvasive anthropometric approach for the measurement of kyphosis and lordosis.

SUMMARY OF BACKGROUND DATA

Noninvasive approaches were developed to estimate the sagittal curvatures of the spine. However, the magnitude of the estimation error could be high for an important proportion of patients, which leads to a difficult clinical application.

METHODS

The group was composed of 124 female patients with a mean age of 13.5 years (SD 2. 7 years) with Cobb angles ranging from 4 degrees to 66 degrees. Kyphosis and lordosis were measured on the lateral radiograph. The spine sagittal curvature of the same patients was also estimated using the spatial localization of skin markers placed overlying the spinous processes. These coordinates served as input into a simple trigonometric model. Data were collected by means of a stereovideographic technique (Motion Analysis Corp., Santa Rosa, CA).

RESULTS

The intraclass correlation coefficient between both approaches was 0.94 for kyphosis and 0.91 for lordosis; the mean absolute differences were 5 degrees (SD 4 degrees ) and 6 degrees (SD 6 degrees ), respectively. The difference was less than 10 degrees in 91% of the patients for kyphosis, and in 79% for lordosis.

CONCLUSIONS

The proposed technique appears to give more representative results than those presented in the literature. It has the advantage of being part of a global noninvasive postural evaluation. Using this approach in a systematic manner could help reduce radiograph exposure while keeping track of the spine sagittal curvatures.

Idiopathic scoliosis: the relation between the vertebral canal and the vertebral bodies

STUDY DESIGN

The axial length of the vertebral canal and the anterior aspect of the vertebrae were measured in 36 skeletons, 15 with probable idiopathic scoliosis.

OBJECTIVES

To compare the discrepancy in length of the vertebral canal and the anterior spinal column in skeletons having probable idiopathic scoliosis with the degree of deformity.

SUMMARY AND BACKGROUND DATA

In idiopathic scoliosis, the vertebral bodies rotate toward the convexity of the curve, whereas the vertebral canal tends to retain a midline position. The vertebral canal therefore will be relatively short. The degree of shortening has not been described previously, nor its relation with the degree of deformity.

METHODS

The axial length of the vertebral canal and the anterior aspect of the vertebral bodies were measured in 36 skeletons: 8 with normal spines, 13 with kyphosis, and 15 with probable idiopathic scoliosis. The relative shortening in the scoliotic spines was correlated with the Cobb angle and the degree of rotation.

RESULTS

No significant difference in length was found between the vertebral canal and the vertebral column in the normal spines. The kyphotic spines had canals significantly longer than the vertebral length (P<0.025). All but one of the scoliotic spines had short vertebral canals (P<0.01). The degree of discrepancy was related to the Cobb angle (r = -0.50; P< 0.05), and particularly to the degree of rotation (r = -0.88; P< 0.001).

CONCLUSIONS

The findings have surgical and etiologic implications. The results are consistent with a conceivable hypothesis that in some patients with idiopathic scoliosis, there may be impaired growth in the length of the spinal cord, the posterior elements are tethered, and as the vertebral bodies continue to grow, they become lordotic and then rotate.

Total en-bloc spondylectomy for correcting congenital kyphosis

STUDY DESIGN

A case report of congenital kyphosis corrected using a total en-bloc spondylectomy.

OBJECTIVES

To report a new surgical technique for the treatment of congenital kyphosis with myelopathy.

SETTING

Department of Orthopedic Surgery, Akita University School of Medicine, Akita, Japan.

METHODS

A 16-year-old boy who showed a 61 degrees angular kyphosis and a 32 degrees scoliosis from T6 to T9 due to the failure of the vertebral bodies formation in T7 and T8 was treated with a total en-bloc spondylectomy.

RESULTS

The kyphosis was corrected to 26 degrees (57.3%) and the scoliosis was corrected to 5 degrees (84.4%) postoperatively. Three years postoperatively, no loss of correction has occurred and the patient has no complaints.

CONCLUSIONS

Total en-bloc spondylectomy is one of the useful surgical procedures for correction of congenital kyphosis Type I, with a high correction rate. Spinal Cord (2000) 38, 382 - 385.

Case study: acceleration/deceleration injury with angular kyphosis

OBJECTIVE

To discuss the case of a patient who received upper cervical chiropractic care after trauma-induced arcual kyphosis in the cervical spine. A practical application of conservative management for posttrauma cervical spine injury in the private office setting is described.

CLINICAL FEATURES

A 17-year-old female patient suffered an unstable C3/C4 motor segment after a lateral-impact motor vehicle collision. Additional symptoms on presentation included vertigo, tinnitus, neck and shoulder pain, and confusion.

INTERVENTION AND OUTCOME

Conservative management consisted exclusively of upper cervical-specific adjustments guided by radiographic analysis and paraspinal bilateral skin temperature differential analysis of the cervical spine. During 10 weeks of care and 22 office visits, all symptoms subsided and the instability of C3/C4 motor segment appeared to be completely resolved.

CONCLUSION

This study provides support for the use of upper cervical chiropractic management in cervical spine trauma cases. The clinical work-up consisted of physical examination, radiographic analysis, computer-administered and scored cognitive function testing, and audiometric examination. After conservative care, these examinations were repeated and demonstrated that the objective findings concurred with the subjective improvements reported by the patient.

Pulmonary hypoplasia in the myogenin null mouse embryo

Although fetal breathing movements are required for normal lung development, there is uncertainty concerning the specific effect of absent fetal breathing movements on pulmonary cell maturation. We set out to evaluate pulmonary development in a genetically defined mouse model, the myogenin null mouse, in which there is a lack of normal skeletal muscle fibers and thus skeletal muscle movements are absent in utero. Significant decreases were observed in lung:body weight ratio and lung total DNA at embryonic days (E)14, E17, and E20. Reverse transcriptase/polymerase chain reaction, in situ immunofluorescence, and electron microscopy revealed early lung cell differentiation in both null and wild-type lungs as early as E14. However at E14, myogenin null lungs had decreased 5'-bromo-2-deoxyuridine incorporation compared with that of wild-type littermates, whereas at E17 and E20, increased Bax immunolabeling and terminal deoxyribonucleotidyl transferase-mediated dUTP-biotin nick-end labeling staining were detected in the myogenin null mice but not in the wild-type littermates. These observations highlight the importance of skeletal muscle contractile activity in utero for normal lung organogenesis. Null mice lacking the muscle-specific transcription factor myogenin exhibit a secondary effect on lung development such that decreased lung cell proliferation and increased programmed cell death are associated with lung hypoplasia.

The relative influence of vertebral body and intervertebral disc shape on thoracic kyphosis

OBJECTIVE

The aim of this study was to quantify the morphology or shape of thoracic vertebral bodies and intervertebral discs, and to examine the ex vivo association of thoracic kyphosis with these shape parameters.

DESIGN

A quantitative, retrospective study design was applied to define vertebral body and disc influences on thoracic kyphosis.

BACKGROUND

Age-related progression of thoracic kyphosis is a well-defined process that is influenced by the morphology of vertebral bodies. However, little is known about the contribution of intervertebral disc shape to the thoracic curvature.

METHODS

Vertebral and disc morphology, as represented by antero-posterior height ratios, were quantified in 93 lateral spine radiographs and midsagittal computed tomography films of ex vivo spines. Kyphosis was indicated by the Cobb angle. Linear and stepwise regression were applied to examine relationships for cumulative (T1-T12) and regional (T4-T9) analyses.

RESULTS

Vertebral morphology was highly predictive of thoracic curvature, while a poorer association was noted for disc morphology. The combined influence of both accounted for >85% of the variability in kyphosis. There was a trend for a more pronounced anterior wedge configuration of the midthoracic vertebral bodies and discs. Higher associations between variables were also noted in this region.

CONCLUSIONS

The normal kyphosis of the thoracic spine reflects the morphological adaptation of both the vertebral bodies and intervertebral discs.

RELEVANCE

This study contributes new data on the thoracic spine, particularly the characteristics of thoracic discs and their contribution to kyphosis genesis. Future directions for morphology studies should encompass more detailed examination of the thoracic discs and greater emphasis on the midthoracic segments, considering the prevalence of osteoporosis related fractures and subsequent deformity at these levels.

Pathogenetic sequence for aneurysm revealed in mice underexpressing fibrillin-1

Dissecting aortic aneurysm is the hallmark of Marfan syndrome (MFS) and the result of mutations in fibrillin-1, the major constituent of elastin-associated extracellular microfibrils. It is yet to be established whether dysfunction of fibrillin-1 perturbs the ability of the elastic vessel wall to sustain hemodynamic stress by disrupting microfibrillar assembly, by impairing the homeostasis of established elastic fibers, or by a combination of both mechanisms. The pathogenic sequence responsible for the mechanical collapse of the elastic lamellae in the aortic wall is also unknown. Targeted mutation of the mouse fibrillin-1 gene has recently suggested that deficiency of fibrillin-1 reduces tissue homeostasis rather than elastic fiber formation. Here we describe another gene-targeting mutation, mgR, which shows that underexpression of fibrillin-1 similarly leads to MFS-like manifestations. Histopathological analysis of mgR/mgR specimens implicates medial calcification, the inflammatory-fibroproliferative response, and inflammation-mediated elastolysis in the natural history of dissecting aneurysm. More generally, the phenotypic severity associated with various combinations of normal and mutant fibrillin-1 alleles suggests a threshold phenomenon for the functional collapse of the vessel wall that is based on the level and the integrity of microfibrils.

Residual deformity of the spinal canal in patients with traumatic paraplegia and secondary changes of the spinal cord

INTRODUCTION

The effect of spinal deformity with posttraumatic kyphosis and stenosis of the spinal canal in producing secondary changes of the spinal cord has been discussed for quite some time. Since the advent of magnetic resonance imaging (MRI), 20-40% of patients with posttraumatic paraplegia are found to develop hydromyelia. PURPOSE OF OUR STUDY: To evaluate the influence of residual spinal deformity, defined by the extent of the posttraumatic kyphosis and stenosis, in the development of posttraumatic hydromyelia.

MATERIAL AND METHODS

Two hundred and seven cases of traumatic paraplegia with MRI follow-up were reviewed retrospectively. A minimum of 3 years duration between trauma and MRI study was required (mean 10.6 years [3.2-38.3]). For statistical analysis two groups of patients were formed: with hydromyelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegia were noted.

RESULTS

We found that 53 patients had hydromyelia. A highly significant correlation was found for the extent of spinal stenosis and the amount of kyphosis. Cluster analysis indicated that patients with more than 15 degrees of posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurological function was not proven to have any influence towards the development of hydromyelia.

CONCLUSIONS

These results support the idea that chronic mechanical stress to the spinal cord increases the risk for the development of hydromyelia. Surgical reconstruction should be considered for all patients to prevent secondary changes of the spinal cord.