The bone dysplasias are a heterogeneous group of disorders arising from intrinsic abnormality of bone and cartilage growth and function. All are genetic. Most result in extreme small stature (dwarfism). Historically, emphasis was primarily on diagnostic identification of specific disorders in infants (including differentiating lethal and non-lethal forms), and on the clinical history to be anticipated in infants and children with each of these specific processes. Even in children there is exceedingly limited information of quality and virtually no controlled studies of the effects of intervention. For the most part, information about affected adults is even less complete and even less rigorous. Presented here are a series of examples of medical and adaptive issues in adults affected by one or another of the genetic skeletal dysplasias. Topics discussed include: approach to adults with no specific diagnosis; medical issues that cross diagnostic boundaries (osteoarthritis in the "E" disorders, obstructive apnea, issues in pregnancy in women with dwarfing disorders, activities of daily living, and quality of life assessments); diagnosis-specific problems of adulthood (spinal stenosis in achondroplasia, hearing loss in osteogenesis imperfecta, and malignancy risk in multiple exostoses); adult problems that must be addressed in childhood in order to be prevented (achondroplasia and kyphosis, and cervical spine abnormalities in Morquio syndrome); survival conundrums (why some live unexpectedly and others die unexpectedly). Emphasis is placed on the difficulties intrinsic to trying to learn about needs and expectations in generally rare genetic processes.(c) 2007 Wiley-Liss, Inc.

OBJECT: Achondroplasia is a hereditary form of dwarfism caused by a defect in endochondral bone formation, resulting in skeletal abnormalities including short stature, shortened limb bones, macrocephaly, and small vertebral bodies. In the pediatric population, symptomatic spinal stenosis occurs at all spinal levels due to the abnormally narrow bone canal. In this study, clinical outcomes were assessed in children with achondroplasia after spinal canal decompression. METHODS: A retrospective review was conducted involving pediatric patients with heterozygous achondroplasia and symptomatic stenosis after decompressive procedures at the authors' institution within a 9-year period. Measured outcomes included resolution of symptoms, need for repeated surgery, presence of fusion, development of deformity, and complications. Forty-four pediatric patients underwent a total of 60 decompressive procedures. The average patient age at surgery was 12.7 years (range 5-21 years). Forty-nine operations were performed for initial treatment of stenosis, and 11 were performed as revision surgeries on previously operated levels. A large proportion of patients (> 60%) required additional cervicomedullary decompressions, most often preceding the symptoms of spinal stenosis. Of the initial procedures, decompression locations included 32 thoracolumbar (65%), 10 lumbar (20%), four cervical (8%), two cervicothoracic (4%), and one thoracic (2%). Forty-three of the decompressive procedures (72%) included spinal fusion procedures. Of the 11 revisions, five were fusion procedures for progressive deformity at levels previously decompressed but not fused (all thoracolumbar), five were for decompressions of symptomatic junctional stenosis with extension of fusion, and one was for repeated decompression at the same level due to recurrence of symptomatic stenosis. CONCLUSIONS: Decompression of the spinal canal in pediatric patients with achondroplasia can be accomplished safely with significant clinical benefit. Patients with a history of cervicomedullary compression may be at an increased risk of developing symptomatic stenosis prior to adolescence. Fusion procedures are recommended in patients with a large decompression overlying a thoracolumbar kyphosis to avoid progressive postoperative deformity.

The authors review the management of thoracolumbar kyphotic deformity in cases of achondroplasia. The presence of angular thoracolumbar kyphosis in achondroplasia is well recognized. In children this is initially a nonfixed deformity that persists, however, in more than 10% of individuals and becomes a fixed thoracolumbar kyphotic deformity. Additionally, with the coexistent spinal canal stenosis, neurological damage can occur and manifest as spinal cord or cauda equina compression. The nature of this condition, the natural history, and management options are discussed. Anatomical and biomechanical factors relevant to the condition are specifically highlighted. Avoidance of pitfalls in the management of these patients is discussed for both pediatric and adult patients.

STUDY DESIGN: Retrospective radiograph and chart review. OBJECTIVES: To assess the safety, efficacy, and complications after posterior spinal arthrodesis with instrumentation for thoracolumbar kyphosis in the pediatric achondroplast. SUMMARY OF BACKGROUND DATA: The conventional approach of anterior and posterior arthrodesis has achieved minimal correction, avoided instrumentation, and had a high risk of neurologic deterioration. To the current authors' knowledge, there are only two reports of successful instrumentation with pedicle screw fixation for kyphosis in pediatric achondroplasts; the outcome of such procedures remains largely unknown. METHODS: The current authors evaluated the results of posterior spinal arthrodeses with instrumentation performed between 1998 and 2001 on 12 consecutive patients (mean age, 12 years). Indications for arthrodesis were concomitant laminectomy for neurologic symptoms or progressive deformity. Arthrodesis methods included anterior and posterior arthrodesis (5 patients) and posterior arthrodesis only (7 patients). Intraoperative somatosensory-evoked potentials, pedicle screw stimulation, and/or a wake-up test were used to confirm neurologic status in all patients. RESULTS: Successful fusion was obtained in all patients. No intraoperative or postoperative neurologic deterioration was encountered. Mean improvement in kyphotic deformity was 50%. Complications included three instrumentation fractures (2 patients) and one dural leak. Parents rated outcome as excellent (4), good (6), and fair (2). No patients have subsequently experienced deformity progression. CONCLUSIONS: Spinal arthrodesis with vertebral body and/or pedicle screw instrumentation was a reliable technique for treating thoracolumbar kyphosis in achondroplasia and did not precipitate any of the neuromonitoring difficulties or neurologic deficits that have been reported in previous studies.

Achondroplasia is a skeletal dysplasia that manifests as short stature. Impairment and complications range over many disciplines including orthopedics, pediatrics, neurology, and otolaryngology. The major impairments of the extremities are short limbs, limited elbow and hip extension, and knee and leg deformities that can cause disabilities in arm function and locomotion. Hydrocephalus, a narrow foramen magnum, spinal deformity, and spinal canal stenosis can cause neurological problems, leading to disabilities in locomotion, communication, and learning. Malfunctions of the otolaryngeal system such as otitis media, upper respiratory obstruction, deafness, speech delay, and malocclusion are interrelated and can also lead to disabilities in communication and learning. Although such disabilities may cause social handicaps, most children receive a normal education. Their social maturity scale is comparable to that of normal children, but their scale of locomotion is not. The reported occupational level of female adult patients is lower than that of their unaffected siblings. When managing patients, orthopedists should consider the overall aspects of achondroplasia, including natural development and complications other than orthopedic factors.

Anterior bulging of the abdomen and posterior protrusion of the buttocks are externally visible deformities reflecting lumbosacral hyperlordosis. Imbalance in pelvic femoral muscles may account for this posture. Despite the clinical significance of hyperlordosis, its surgical treatment has not been well-described. In the current preliminary study, the authors compare two techniques used at the authors' institution for lower limb lengthening, one of which affects the correction of lumbosacral hyperlordosis. Ten patients had bilateral lower extremity lengthening procedures. Seven patients had bilateral tibial lengthening and three patients had combined femoral and tibial lengthening. Ring external fixators were used. Correction of hyperlordosis was assessed by comparing four radiographs with measurements in the sagittal plane obtained preoperatively with those at the latest followup. In the femoral lengthening group, the average preoperative lumbar lordosis angle was 18 degrees, the lumbosacral joint angle was 12 degrees, the sacral inclination angle was 58.3 degrees, and the sacrohorizontal angle was 31 degrees. The mean changes at the latest followup were: lumbar lordosis angle (+1 degree), lumbosacral joint angle (+0.3 degrees), sacral inclination angle (-19 degrees), and sacrohorizontal angle (-15 degrees). In the tibia lengthening group, all parameters were relatively unaltered at the last followup compared with their preoperative levels. Tibial lengthening had no effect on lumbosacral hyperlordosis. However, femoral lengthening resulted in an improved apparent lumbosacral hyperlordosis, although the lumbar lordosis angle was not changed significantly. The change in sacrum tilting provides a likely explanation for the improvement in cosmetic hyperlordosis observed in patients who have had femoral lengthening.

Skeletal dysplasias, disorders of abnormal bone and cartilage development, are a heterogeneous group, each disorder with its own genetics, prevalence, prognosis, and treatment. More than 150 distinct conditions have been identified. Despite their obvious differences, the osteochondrodysplasias share many clinical and radiographic features. These patients present to the orthopedic surgeon for evaluation of disproportionate short stature, which may be apparent at birth or manifest itself only with further growth. This article discusses bone dysplasias commonly associated with spinal abnormalities. Spinal pathology can lead to deformity, neurologic sequelae, pain, and cardiopulmonary compromise and further contribute to short stature.

Transient kyphotic deformity arises in most infants with achondroplasia. In a minority, a fixed and angular kyphosis develops, which can cause serious neurologic sequelae later in life. We assessed a protocol for preventing development of such fixed kyphosis in a sequential, unselected series of 66 infants with achondroplasia. This study demonstrates the efficacy of early prohibition of unsupported sitting and, in those in whom such prohibition proves insufficient, use of bracing. When the proposed algorithm was followed, none of the infants had development of a progressive kyphotic deformity. On this basis, it appears that the secondary risks of angular kyphosis, previously estimated to be between 10 and 15% in individuals with achondroplasia, can be completely eliminated.

The profile of the achondroplastic dwarf reflects abnormalities in the shape of the spine, particularly in the lumbosacral area. We hypothesize that these abnormalities and the resultant symptoms are secondary and avoidable rather than heritable and inevitable. Because the heads of achondroplastic children are enlarged (n = 50), loading of the vertical spine is increased. Unusually lax ligaments and misshapen vertebrae predispose the spine to yielding under vertical stress. Children and adults uniformly have hip flexion contractures (n 105); these are hypothesized to be the result of uncorrected lumbosacral lordosis. The volume of the spinal canal, reduced by the spinal stenosis of achondroplasia, is decreased additionally by lordosis; some neurologic deficits of achondroplasia are caused by this abnormal curvature. This hypothesis bears practically on treating this common form of dwarfism.

It is generally believed that diets containing increased amounts of polyunsaturated fatty acids (PUFA) result in improved canine skin and hair coat (SHC). However, the extent to which dietary fat amount and type play a role remains to be systematically investigated. The objective of this study was to investigate the role of both increased dietary fat amount and type on SHC assessments of dogs. Improvements of SHC conditions were investigated after feeding three diets containing increased total dietary fat (i.e. 13% total fat) for 12 weeks in relation to a lower fat acclimation diet (i.e. 9% total fat). The higher fat diets varied in polyunsaturated and saturated fat types and amounts but total fat was kept constant. Skin and hair coat assessments were performed at selected intervals by a trained group of veterinarians and graduate students. In addition, hair lipids were fractionated by thin layer chromatography after extraction of plucked hair samples. Significant improvements were found in hair coat glossiness and softness in all dogs fed the higher fat diets in relation to the acclimation diet. Improvements as a result of fat type were also seen but only at 12 weeks. A parallel finding was a marked increase in hair cholesteryl ester content determined at the end of the study at which time SHC scores were significantly improved. Skin and hair coat condition improvements may thus be related to increased cholesteryl ester deposited on the hair shaft surface when high fat diets are fed. Whereas this finding is preliminary, hair lipid analysis may be a useful, non-invasive technique with which to help assess dietary effects on canine SHC.

The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al.[in Phys. Rev. Lett. 96, 165002 (2006)10.1103/PhysRevLett.96.165002]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al.[Phys. Rev. Lett. 67, 991 (1991)10.1103/PhysRevLett.67.991] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.

Single-fiber activity synchronous with breathing was recorded from the dorsal roots of thoracic segments in anesthetized cats. Activity of these fibers varied in frequency and in phase relationship to the respiratory cycle. It is concluded that large numbers of proprioceptors within the thoracic wall are activated during each inspiration and each expiration.

Wear debris generated from total joint arthroplasty may elicit a granulomatous and inflammatory response and has also been implicated in the development of osteolysis. Technical difficulty in retrieval and isolation of wear material from tissues has hindered the study of their physicochemical properties. The purpose of this study was to retrieve and analyze metallic wear debris from periprosthetic tissue obtained during revision arthroplasty. Tissue from six osteoarthritic patients was obtained during revision arthroplasty. The tissue was minced and then heated in a sodium dodecyl sulfate solution. Undigested tissue was incubated sequentially with papain and pepsin solutions. Metallic wear debris retrieved from the digestion procedure was analyzed by scanning electron microscopy. Wear fragments were seen as irregularly shaped flakes, splinters and polyhedral structures ranging from 1 to 100 microns in size. These structures appeared to be free from non-metallic surface-adherent material. Energy dispersion spectroscopy verified the presence of cobalt, chrome and molybdenum which comprised the implant alloy. Fatigue lines were observed on the surface suggesting brittle wear. Our technique for isolating metallic fragments facilitates the retrieval and preparation of wear debris for analysis of physicochemical properties and how wear debris interacts with cellular elements in surrounding tissue.

Adult spinal deformity may occur as the result of a number of conditions and patients may present with a heterogeneous group of symptoms. Multiple etiologies may cause spinal deformity; however, symptoms are associated with progressive and asymmetric degeneration of the spinal elements potentially leading to neural element compression. Symptoms and clinical presentation vary and may be related to progressive deformity, axial back pain, and/or neurologic symptoms. Spinal deformity is becoming more common as adults 55-64 years of age are the fastest growing proportion of the U.S. population. As the percentage of elderly in the United States accelerates, more patients are expected to present with painful spinal conditions, potentially requiring spinal surgery. The decision between operative and nonoperative treatment for adult spinal deformity is based on the severity and type of the patient's symptoms as well as the magnitude and risk of potential interventions.

BACKGROUND: Instrumentation and fusion to the sacrum/pelvis has been a mainstay in the surgical treatment of scoliosis in patients with Duchenne muscular dystrophy since the development of the intrailiac post. It is recommended for correcting pelvic obliquity. However, caudal extent of instrumentation and fusion has remained a matter of considerable debate. This study was performed to determine the efficacy and safety of stopping segmental pedicle screw constructs at L5 during surgical treatment of scoliosis associated with Duchenne muscular dystrophy (DMD). METHODS: From May 2005 to June 2007, a total of 20 consecutive patients underwent posterior spinal fusion and segmental pedicle screw instrumentation only to L5 for scoliosis secondary to DMD. All patients had progressive scoliosis, difficulty sitting, and back pain before surgery. A minimum 2-year follow-up was required for inclusion in this study. Assessment was performed clinically and with radiological measurements. The Cobb angles of the curves and spinal pelvic obliquity were measured on the coronal plane. Thoracic kyphosis and lumbar lordosis were measured on the sagittal plane. These radiographic assessments were performed before surgery, immediately after surgery, and at a 3-month interval thereafter. The operating time, blood loss, and complications were evaluated. Patients were questioned about whether they had difficulty sitting and felt back pain before surgery and at 6 weeks, 1 year, and 2 years after surgery. RESULTS: A total of 20 patients, aged 11-17 years, were enrolled. The average follow-up period was 37 months. Preoperative coronal curves averaged 70 degrees (range 51 degrees -85 degrees ), with a postoperative mean of 15 degrees (range 8 degrees -25 degrees ) and a mean of 17 degrees (range 9 degrees -27 degrees ) at the last follow-up. Pelvic obliquity improved from 13 degrees (range 7 degrees -15 degrees ) preoperatively to 5 degrees degrees (range 3 degrees -8 degrees ) postoperatively and 6 degrees (range 3 degrees -9 degrees ) at the last follow-up. Good sagittal plane alignment was recreated and maintained. Only a small loss of correction of scoliosis and pelvic obliquity was noted. The mean operating time was 271 min (range 232-308 min). The mean intraoperative blood loss was 890 ml (range 660-1260 ml). The mean total blood loss was 2100 ml (range 1250-2880 ml). There was no major complication. All patients reported that difficulty sitting and back pain were alleviated after surgery. CONCLUSION: Segmental pedicle screw instrumentation and fusion only to L5 is safe and effective in patients with DMD scoliosis of <85 degrees and pelvic obliquity of <15 degrees . Good sagittal plane alignment was achieved and maintained. All patients benefited from surgery in terms of improved quality of life. There was no major complication.

OBJECTIVES: We evaluated the results of short-segment posterior instrumentation of thoracolumbar burst fractures and investigated correlations between radiographic and functional results as well as factors that affected correction losses. METHODS: We reviewed 48 patients (30 males, 18 females; mean age 40+/-14 years; range 18 to 67 years) who underwent short-segment posterior instrumentation with pedicle screws and fusion. The most common involvement was at L1 in 18 patients (37.5%), followed by T12 in 11 patients (22.9%). According to the Frankel grading system, six patients had complete, 14 patients had incomplete neurologic deficits. The Cobb angles were measured, and canal remodeling was assessed by computed tomography. Modified functional results were derived using the Denis pain and work scales. The mean follow-up was 21.7+/-9.1 months (range 12 to 48 months). RESULTS: The mean correction in the Cobb angle was 18.2+/-8.6 degrees (p<0.01), the mean correction loss was 7.4+/-5.7 degrees (p<0.01), and the mean canal remodeling was 51.3+/-9.3%(p<0.001). There was a significant correlation between Cobb angle correction and correction loss (r=0.38, p<0.01). An intraoperative correction of greater than 15 degrees was significantly associated with a greater correction loss (p<0.05). Patients with a correction loss of more than 10 degrees had a significantly poorer Denis pain score and modified functional result (p<0.05). Modified functional results were excellent in 16 patients (33.3%), good in 23 patients (47.9%), fair in seven patients (14.6%), and poor in two patients (4.2%). At final follow-ups, the Cobb angle was not correlated with functional results (p>0.05). All the patients having incomplete neurologic deficits improved by at least 1 Frankel grade. CONCLUSION: An intraoperative correction exceeding 15 degrees is significantly associated with a greater correction loss, which in turn has a significantly adverse effect on functional results.

Scheuermann's disease is the most common cause of structural kyphosis in adolescents. The kyphotic deformity is frequently attributed to "poor posture," resulting in delayed diagnosis and treatment. Indications for treatment remain somewhat debated, because the true natural history of the disease has not been clearly defined. Brace treatment is almost always successful in patients with kyphosis between 55 degrees and 80 degrees if the diagnosis is made before skeletal maturity. Kyphosis greater than 80 degrees in the thoracic spine or 65 degrees in the thoracolumbar spine is almost never treated successfully without surgery in symptomatic patients. Surgical treatment in adolescents and young adults should be considered if there is documented progression, refractory pain, loss of sagittal balance, or neurologic deficit. The major postoperative complication after surgical treatment is junctional kyphosis proximally or distally, which is usually related to not including all levels of the kyphosis or overcorrection of the deformity (>50%). With proper patient selection, excellent outcomes can be expected with nonoperative or operative treatment in patients with Scheuermann's disease.

One third of patients with achondroplasia develop spinal stenosis requiring surgical intervention. However, this condition rarely develops before the age of 15 years. The goal of the current study was to identify anatomical factors and clinical symptoms associated with early presentation of lumbar stenosis in such patients. The charts of 22 pediatric patients with achondroplasia who developed lumbar spinal stenosis requiring surgery (subjects) were reviewed retrospectively, focusing on clinical presentation, physical examination findings, and radiographic data. These findings were compared with those of a group of patients who had not developed stenotic symptoms (controls). Analysis was performed using chi test. Significance was set at P < 0.05. All 22 subjects presented with neurogenic claudication (weakness, pain, and/or numbness), and 77% had bladder incontinence. Compared radiographically with controls, the subjects had a significantly larger average percentage decrease in the transverse interpedicular distance from T12 to L5 (-8% vs -19%, respectively) and a significantly greater thoracolumbar kyphosis angle (24.2-degree angle vs 14.1-degree angle, respectively). These features were associated with an increased likelihood of developing symptomatic stenosis. The study indicated that 6 patients (32%) of the control group had caudal widening of the lumbar spine from T12 to L5.

STUDY DESIGN.: A retrospective case series of surgically treated achondroplastic patients with severe thoracolumbar kyphosis. OBJECTIVE.: To evaluate the outcome of surgical treatment for thoracolumbar kyphosis in patients associated with achondroplasia presenting with paraparesis. SUMMARY OF BACKGROUND DATA.: Thoracolumbar kyphosis is one of the frequent skeletal manifestations in patients with achondroplasia. Few papers have been published on the surgical treatment of this condition, especially in skeletally mature patients. METHODS.: Four patients with achondroplasia who developed neurologic deficit due to severe thoracolumbar kyphosis and underwent surgical treatment were evaluated (mean age, 32.5 years; mean follow-up, 3.0 years). Posterior osteotomy with segmental instrumentation was performed in all cases. The surgical procedures included pedicle subtraction osteotomy in 2 patients without a hypoplastic apical vertebra and spondylectomy with reconstruction of the anterior column in 2 patients with a hypoplastic apical vertebra. Neurologic outcomes (JOA scores), correction of kyphosis, and operative complications were assessed. RESULTS.: All patients had gait disturbance, and 2 patients were unambulatory before surgery. The average preoperative JOA score was 5.8 points, which was improved to 9.3 points at the final follow-up (mean recovery rate, 75%). All patients obtained neurologic improvement and became ambulatory either with or without crutches after surgery. The mean preoperative kyphotic angle was 96.3 degrees (range, 57 degrees -117 degrees ). The postoperative angles averaged 55.3 degrees (range, 30 degrees -110 degrees ), yielding a mean correction rate of 43.6%. Neither loss of correction nor pseudarthrosis has been observed during the follow-up period. Partial nerve root laceration and dural tear resulting in transient postoperative muscle weakness were observed in 2 patients as complications. CONCLUSIONS.: Posterior spinal osteotomy with segmental instrumentation is a reasonable surgical option for thoracolumbar kyphosis in patients with achondroplasia. Modification of the surgical procedures depending on the presence or absence of the dysplastic changes of the apical vertebra is necessary to obtain optimal results.

STUDY DESIGN.: Prospective consecutive series. OBJECTIVE.: To evaluate the outcomes of the treatment of acute thoracolumbar burst fractures by transpedicular hydroxyapatite grafting following indirect reduction and pedicle screw fixation. SUMMARY OF BACKGROUND DATA.: In the treatment of thoracolumbar burst fractures, the major problem after posterior correction and instrumentation is failure to support the anterior spinal column, leading to the loss of correction of kyphosis and instrumentation breakage. METHODS.: There were 15 consecutive patients who had thoracolumbar burst fractures and associated incomplete neurologic deficit. They underwent surgery within 4 days of admission, had their implants removed within 1 year, and were prospectively followed for at least 2 years. Following indirect reduction and pedicle screw fixation, transpedicular intracorporeal hydroxyapatite grafting to the fractured vertebrae was performed. Median operating time was 130 minutes, and median blood loss was 155 g. RESULTS.: The neurologic function of all 15 patients improved by at least 1 American Spine Injury Association grade, with 9 (60%) having complete neurologic recovery. Sagittal alignment was improved from a median preoperative kyphosis of 20 degrees to -1 degrees (lordosis) by surgery but was found to have slightly deteriorated to 1 degrees at final follow-up observation. Computerized tomography showed a median spinal canal narrowing of 64%, 22%, and 11%, respectively. There were no instances of instrumentation failure. CONCLUSIONS.: Posterior indirect reduction, transpedicular hydroxyapatite grafting, and pedicle screw fixation could provide reliable neurologic improvement in patients with incomplete neurologic deficit, and could prevent the development of kyphosis. This technique does not require fusion to a segment, thereby preserves thoracolumbar motion.

BACKGROUND: In ankylosing spondylitis (AS), the spine with osteoporotic changes is fragile and vulnerable to trauma. Patients may develop spinal pseudoarthrosis (SP), whose clinical features are usually misdiagnosed as a tuberculous infection. This study reports our experience with surgical treatment for SP in AS. METHODS: Eight patients with AS and SP at the thoracolumbar area were treated surgically and followed-up for at least 3 years. All had persistent back pain and progressive kyphosis. One patient had neurologic deficits preoperatively. Anterior debridement and interbody fusion followed by posterior stabilization were performed in all patients. A posterior corrective osteotomy was additionally done in 3 patients whose kyphotic angle exceeded 45 degrees. RESULTS: All patients with persistent back pain obtained significant pain relief postoperatively. On a visual analogue scale, there was an average improvement of 43 points on the clinical scores. The patient with neurologic deficits showed improvement after the operation. Solid bony fusion was achieved in an average of 7.5 months, and correction of the kyphotic angle averaged 18.6 degrees. CONCLUSIONS: Spinal pseudoarthrosis should be considered in patients with AS, and must be differentiated from tuberculous and other infections. The results of this study show that pain relief and correction of the kyphotic deformity can be achieved by surgical treatment for ankylosing spondylitis complicated with pseudoarthrosis.

PURPOSE: To determine the effect of a thoraco-lumbar-sacral orthosis (TLSO) on the distribution of body-seat interface pressure in children with concomitant scoliosis and pelvic obliquity and to determine the effects of two methods commonly used in customized seating--elevation (push up) of the lower side of the pelvis or a wedge insertion beneath the raised pelvis--on the distribution of body-seat interface pressure. METHODS: The study population comprised 15 children with an underlying neuromuscular disorder. All had scoliosis and pelvic obliquity when seated, and used a TLSO during sitting. Body-seat interface pressure was measured using the QA Pad. Maximum pressure, mean pressure and contact area were recorded at baseline and at 10 degrees 'push up' and 10 degrees wedge insertion, with and without the TLSO. X-rays were performed with and without the orthosis at baseline position. RESULTS: The TLSO reduced the scoliosis deformity by a mean of 5.3 degrees and significantly (p < 0.05) reduced the mean pressure and contact area in the sub-group of patients whose pelvic obliquity was contralateral to the side of the curve. Seat adjustment did not have any significant effect on pressure readings. CONCLUSION: Application of a TLSO in a child with scoliosis and contralateral pelvic obliquity significantly reduced the spinal curvature and interface sitting pressure. Manipulation of sitting by use of wedges under the pelvis had no significant effect on pressure distribution.

STUDY DESIGN: A meta-analysis was performed based on 53 cases of cervical eosinophilic granuloma reported in the literature and 1 in an adult treated by the authors. OBJECTIVE: To stress the clinical and radiologic differences between cervical and thoracolumbar spinal eosinophilic granuloma and to point out differences between adults and children with cervical eosinophilic granuloma to avoid false diagnosis. SUMMARY OF BACKGROUND DATA: Until now, cervical eosinophilic granuloma has been reported in 43 children and 9 adults. In 1 case the age is unknown. In previous studies, differences between adults and children with cervical eosinophilic granuloma have not been analyzed, nor has cervical eosinophilic granuloma been compared with thoracolumbar eosinophilic granuloma. METHODS: All reported cases of cervical eosinophilic granuloma were analyzed concerning age and sex distribution, clinical and radiologic presentation, therapy, and outcome. The authors' case in a 46-year-old patient is discussed. RESULTS: The presenting symptoms of cervical eosinophilic granuloma are usually pain and restricted range of motion. In contrast to eosinophilic granuloma of the thoracic spine and lumbar spine, the neurologic symptoms are less frequent, and the first radiographic sign is an osteolytic lesion. Vertebra plana is a rare sign in cervical eosinophilic granuloma. In children, the middle cervical spine is most often affected, whereas in adults it is the second vertebra. The outcome of the patients has been good in most cases, independently of treatment. CONCLUSION: In most cases of cervical eosinophilic granuloma, immobilization is an adequate therapy. If the process continuous to progress, radiotherapy is recommended. Surgical treatment should be reserved for cases with instability or neurologic defects.