Posterior vertebral column resection in early onset spinal deformities

Purpose

Early onset spinal deformities (EOSD) can be life-threatening in very young children. In the growing spine, surgical intervention is often unavoidable and should be carried out as soon as possible. A deformed section of the spine not only affects the development of the remaining healthy spine, but also that of the chest wall (which influences pulmonary function), the extremities and body balance. Posterior vertebral column resection (PVCR) represents an effective surgical solution to address such problems. However, reports in the literature concerning PVCR are mostly limited to its use in adolescents or adults. The purpose of this study was to illustrate our experience with PVCR in EOSD and to describe the surgical technique with respect to the unique anatomy of young children.

Materials and methods

Four children [mean age 3.7 (range 2.5–5.2) years] with severe spinal deformity underwent PVCR through a single approach. Multimodal intraoperative monitoring was used in all cases. Surgery included one stage posterior circumferential resection of one vertebral body along with the adjoining intervertebral discs and removal of all posterior elements. A transpedicular screw-rod system was used for correction and stabilisation. Fusion was strictly limited to the resection site, allowing for later conversion into a growing rod construct at the remaining spine, if necessary. Relevant data were extracted retrospectively from patient charts and long spine radiographs.

Results

The mean operation time was 500 (range 463–541) min, with an estimated blood loss of 762 (range 600–1,050) ml. Mean follow-up time was 6.3 (range 3.5–12.4) years. After PVCR, the mean Cobb angle for scoliosis was reduced from 69° (range 50–99°) to 29° (5–44°) and the sagittal curvature (kyphosis) from 126° (87–151°) to 61° (47–75°). The mean correction of scoliosis was 57 % (18–92°) and of kyphosis, 51 % (44–62°). There were no spinal cord-related complications. In three patients, spinal instrumentation for growth guidance (fusion less growing rod technique) was applied. Two patients had complications: one patient had a complication of anesthesia, halo pin failure, and revision surgery with extension of the instrumentation cranially due to loss of correction; the second patient had a postoperative infection, which required plastic reconstructive measures.

Conclusion

PVCR appears to be an effective technique to treat severe EOSD. There are important differences in its use in young children when compared with older patients. In patients with EOSD, additional surgical procedures are often necessary during growth, and hence non-fusion instrumentation beyond the vertebral resection site is advantageous, as it permits spinal growth and the later addition of fusion.     

Isolated posterior instrumentation for selected cases of thoraco-lumbar spinal tuberculosis without anterior instrumentation and without anterior or posterior bone grafting

Purpose

The aim of this prospective study is the analysis of the clinical and radiological outcomes of active thoraco-lumbar spinal tuberculosis treated with isolated posterior instrumentation without any posterior bone grafting or anterior inter-body bone grafting or anterior instrumentation.

Methods

The study was a prospective follow-up of 25 patients with active thoraco-lumbar spinal tuberculosis who underwent posterior spinal instrumentation with pedicle screws and rods. These patients had posterior stabilization of the involved segment of the spine without anterior or posterior bone grafting. The mean duration of follow-up was 3.3 years and the minimum duration of follow-up was 2 years.

Results

The mean kyphotic angle improved from 32.4° pre-operatively to 7.2° in the early follow-up period. Following a minor loss of correction during follow-up, the mean kyphotic angle settled at 11.5° at the time of final follow-up. Inter-body bony fusion was noticed at the final follow-up in all patients despite the absence of anterior bone grafting or cages.

Conclusion

Posterior instrumented stabilization followed by chemotherapy seems to be adequate for obtaining satisfactory healing of the lesions. Anterior inter-body bony arthrodesis occurs despite the absence of anterior bone grafts or cages. Careful patient selection is critical for successful outcome with this technique.     

Halo-gravity traction in the treatment of severe spinal deformity: a systematic review and meta-analysis

Purpose

Halo-gravity traction has been reported to successfully assist in managing severe spinal deformity. This is a systematic review of all studies on halo-gravity traction in the treatment of spinal deformity to provide information for clinical practice.

Methods

A comprehensive search was conducted for articles on halo-gravity traction in the treatment of spinal deformity according to the PRISMA guidelines. Appropriate studies would be included and analyzed. Preoperative correction rate of spinal deformity, change of pulmonary function and prevalence of complications were the main measurements.

Results

Sixteen studies, a total of 351 patients, were included in this review. Generally, the initial Cobb angle was 101.1° in the coronal plane and 80.5° in the sagittal plane, and it was corrected to 49.4° and 56.0° after final spinal fusion. The preoperative correction due to traction alone was 24.1 and 19.3%, respectively. With traction, the flexibility improved 6.1% but postoperatively the patients did not have better correction. Less aggressive procedures and improved pulmonary function were observed in patients with traction. The prevalence of traction-related complications was 22% and three cases of neurologic complication related to traction were noted. The prevalence of total complications related to surgery was 32% and that of neurologic complications was 1%.

Conclusion

Partial correction could be achieved preoperatively with halo-gravity traction, and it may help decrease aggressive procedures, improve preoperative pulmonary function, and reduce neurologic complications. However, traction could not increase preoperative flexibility or final correction. Traction-related complications, although usually not severe, were not rare.

     

CT angiography of anterior spinal artery in cervical spondylotic myelopathy

Purpose

To identify anterior spinal artery (ASA) infarct or occlusion by CT angiography (CTA) in patients with cervical spondylotic myelopathy (CSM).

Methods

Fourteen patients with CSM were performed CTA of ASA after admission. T2-weighted hyperintensity of MR image was compared with image of CTA of ASA.

Results

All patients presented spinal canal sagittal diameter compression from 10 to 80 % and different T2-weighted hyperintensity of MR images. No ASA infarct or occlusion was found in CSM patients.

Conclusion

ASA infarct or occlusion is not commonly seen in CSM patients with spinal canal sagittal diameter compression less than 80 %. Pathological changes about T2-weighted hyperintensity of MR image in CSM have no close correlation with ASA infarct.     

The use of antibiotic-impregnated fibrin sealant for the prevention of surgical site infection associated with spinal instrumentation

Purpose

The purpose of this study was to determine if the use of antibiotic-impregnated fibrin sealant (AFS) was effective in preventing surgical site infections (SSI) associated with spinal instrumentation.

Methods

In a preliminary study, five pieces of vancomycin-impregnated fibrin sealant, five nuts that were not treated with the sealant, and five nuts that were treated with the sealant were subjected to agar diffusion testing. In a clinical study, the rates of deep SSI were compared between 188 patients who underwent procedures involving spinal instrumentation without AFS (group 1) and 196 patients who underwent procedures involving spinal instrumentation with AFS (group 2).

Results

All five pieces of vancomycin-impregnated fibrin sealant and the five nuts treated with the sealant exhibited antimicrobial efficacy, while the five untreated nuts did not exhibit antimicrobial efficacy in the agar diffusion test. In the clinical study, 11 (5.8 %) of the 188 patients in group 1 acquired a deep SSI, while none (0 %) of the 196 patients in group 2 acquired a deep SSI.

Conclusion

The present study demonstrated that the application of AFS to spinal instrumentation yielded good clinical outcomes in terms of the prevention of postoperative spinal infections. It is hoped that limiting AFS use to patients requiring spinal instrumentation and those with risk factors for SSI will reduce the overall costs while preventing SSIs.     

The association of regional intensity of neurosurgical care with spinal fusion surgery in the USA

Purpose

There is wide regional variability in the volume of procedures performed for similar surgical patients throughout the USA. The purpose of this study was to investigate the association of spinal fusion operations with several socioeconomic factors.

Methods

We performed a retrospective cohort study involving patients who underwent any neurosurgical procedure from 2005 to 2010 and were registered in National Inpatient Sample (NIS). A sub-cohort of patients undergoing spinal operations was also created. Regression techniques were used to investigate the association of the average intensity of neurosurgical care (defined as the average number of neurosurgical procedures per capita) with the average rate of fusions.

Results

In the study period, there were 707,951 patients undergoing spinal procedures, who were registered in NIS. There were significant disparities in the fusion rate among different states (ANOVA, P < 0.0001), which ranged from 0.41 in Maine, where non-fusion surgeries were very predominant, to 0.62 in Virginia, where fusion was the main treatment modality used. In a multivariate analysis, the intensity of neurosurgical care was associated with an increased fusion rate. A similar effect was observed for coverage by private insurance, higher income, urban hospitals, large hospital size, African American patients, and patients with less comorbidities. Hospital location in the northeast was associated with a lower rate in comparison to the midwest, and south. Coverage by Medicaid was associated with lower fusion rate.

Conclusions

We observed significant disparities in the integration of fusion operations in spine surgery practices in the USA. Increased intensity of neurosurgical care was associated with a higher fusion rate.     

Predisposing factors for surgical site infection of spinal instrumentation surgery for diabetes patients

Purpose

Diabetes mellitus (DM) is known as an important risk factor for surgical site infection (SSI) in spine surgery. It is still unclear however which DM-related parameters have stronger influence on SSI. The purpose of this study is to determine predisposing factors for SSI following spinal instrumentation surgery for patients with DM.

Methods

110 DM patients (66 males and 44 females) who underwent spinal instrumentation surgery in one institute were enrolled in this study. For each patient, various preoperative or intraoperative parameters were reviewed from medical records. Patients were divided into two groups (SSI or non-SSI) based on the postoperative course. Each parameter between these two groups was compared. Univariate and multivariate analyses were performed to determine predisposing factor for SSI.

Results

The SSI group consisted of 11 patients (10 %), and the non-SSI group of 99 patients (90 %). Univariate analysis revealed that preoperative proteinuria (p = 0.01), operation time (p = 0.04) and estimated blood loss (p = 0.02) were significantly higher in the SSI group compared to the non-SSI group. Multivariate logistic regression identified preoperative proteinuria as a statistically significant predictor of SSI (OR 6.28, 95 % CI 1.58–25.0, p = 0.009).

Conclusions

Proteinuria is a significant predisposing factor for SSI in spinal instrumentation surgery for DM patients. DM patients with proteinuria who are likely to suffer latent nephropathy have a potential risk for SSI. For them less invasive surgery is recommended for spinal instrumentation. In this retrospective study, there was no significant difference of preoperative condition in glycemic control between the two groups.     

One-stage anterior debridement,bone grafting and posterior instrumentation vs. single posterior debridement,bone grafting,and instrumentation for the treatment of thoracic and lumbar spinal tuberculosis

Purpose

The aim of this study was to compare single posterior debridement, interbody fusion and instrumentation with one-stage anterior debridement, interbody fusion and posterior instrumentation for treating thoracic and lumbar spinal tuberculosis.

Method

From January 2006 to January 2010, we enrolled 115 spinal tuberculosis patients with obvious surgical indications. Overall, 55 patients had vertebral body destruction, accompanied by a flow injection abscess or a unilateral abscess volume greater than 500 ml. The patients underwent one-staged anterior debridement, bone grafting and posterior instrumentation (group A) or single posterior debridement, bone grafting and instrumentation (group B). Clinical and radiographic results for the two groups were analyzed and compared.

Results

Patients were followed 12–36 months (mean 21.3 months), Fusion occurred at 4–12 months (mean 7.8 months). There were significant differences between groups regarding the post-operative kyphosis angle, angle correction and angle correction rate, especially if pathology is present in thoracolumbar and lumbar regions. Operative complications affected five patients in group A, and one patient in group B. A unilateral psoas abscess was observed in three patients 12 months postoperatively. In one of them, interbody fusion did not occur, and there was fixation loosening and interbody absorption. All of them were cured by an anterior operation.

Conclusion

Anterior debridement and bone grafting with posterior instrumentation may not be the best choice for treating patients with spinal tuberculosis. Single posterior debridement/bone grafting/instrumentation for single-segment of thoracic or lumbar spine tuberculosis produced good clinical results, except in patients who had a psoas abscess.     

Combined spinal arthrodesis with instrumentation for the management of progressive thoracolumbar kyphosis in children with mucopolysaccharidosis

Purpose

To evaluate the outcome and complications of a novel technique for the treatment of progressive thoracolumbar kyphosis in children with mucopolysaccharidosis (MPS).

Methods

The medical records and spinal imaging of four consecutive paediatric patients who underwent a single stage anteroposterior spinal fusion with segmental pedicle screw instrumentation were reviewed.

Results

Patients underwent spinal deformity correction at the mean age of 3 years (2.4–3.7) with mean clinical follow-up of 3.2 years (2.1–4.5) and mean postoperative radiographic follow-up was 2.4 years (0.8–3). Preoperative kyphosis was corrected from a mean angle of 65º (63º–70º) to 6.5º (–12º–13º). Vertebral subluxation at the apex of the deformity was corrected from an average 64 % (56–83 %) to 12 % (0–24 %). Spinal cord monitoring with somatosensory evoked potentials (SSEP) was successfully obtained and stable throughout surgery. No instrumentation failure, loss of correction or junctional problems occurred at final follow-up.

Conclusions

Anterior and posterior spinal arthrodesis with segmental pedicle screw instrumentation is a safety and reliable technique for the treatment of severe thoracolumbar kyphosis in children with MPS. This technique achieves excellent correction of the deformity with adequate decompression of the spinal canal. The fusion is limited to the thoracolumbar junction and interferes minimally with the longitudinal growth of the thorax. No neurological complications or intraoperative spinal cord monitoring events occurred. No loss of correction or junctional kyphosis was observed.     

Airport metal detector activation is rare after posterior spinal fusion in children with scoliosis

Purpose

Since the September 11, 2001 terrorist attacks on the World Trade Center in New York City, travel security has become an ever-increasing priority in the United States. Frequent parent and patient inquiry and recent literature reports have generated interest in the impact of heightened security measures on patients with orthopaedic implants, and have indicated increasing rates of metal detector triggering. There are no reports to date, however, evaluating children and adolescents who have undergone posterior spinal fusion for scoliosis, so responses to patient and parent inquiries are not data-driven. The purpose of this study is to determine the frequency of airport metal detector triggering by patients who have had posterior-only spinal fusion and to characterise any potential predictors of metal detector activation.

Methods

A cross-sectional study was performed by interviewing 90 patients who underwent posterior-only spinal fusion for a diagnosis of juvenile or adolescent idiopathic scoliosis and have travelled by air in the past year. Demographic, clinical and surgical instrumentation data were collected and evaluated, along with patients’ reports of airport metal detector triggering and subsequent screening procedures.

Results

Five patients with stainless steel instrumentation (5.6 % of the cohort) triggered an airport walkthrough metal detector, and an additional five patients who did not trigger an airport detector triggered a handheld detector at a different venue. All patients who triggered an airport metal detector had stainless steel instrumentation implanted prior to 2008, and no patient with titanium instrumentation triggered any detector in any venue. All trigger events required subsequent screening procedures, even when an implant card was presented.

Conclusions

In this cohort of children and adolescents with posterior spinal instrumentation, airport walkthrough metal detector triggering was a rare event. Therefore, we advise patients and families with planned posterior scoliosis fusions using titanium instrumentation that airport detection risk is essentially non-existent, and only rare for those with planned stainless steel instrumentation. We no longer issue implant cards postoperatively, as these did not prevent further screening procedures in this cohort.

Level of evidence

Prognostic level 2. Study design: cross-sectional.     

Preoperative halo-gravity traction with and without thoracoscopic anterior release for skeletal dysplasia patients with severe kyphoscoliosis

Purpose

Recent work has shown the safety and efficacy of halo-gravity traction as an operative adjunct. However, there are no reports specifically looking at halo-gravity traction in patients with skeletal dysplasia. Our purpose was to assess the safety and efficacy of traction in children with skeletal dysplasia who present with severe kyphoscoliosis.

Methods

We retrospectively reviewed eight consecutive children with skeletal dysplasia who were treated with halo-gravity traction preoperatively. Six of the patients had a thoracoscopic anterior release prior to the halo-gravity traction. All patients were ambulatory and presented with severe, rigid kyphoscoliosis.

Results

The mean duration of traction was 32 days. There were no neurologic complications with traction or after posterior spinal instrumentation. The majority of kyphoscoliosis correction was with the halo-gravity traction alone: major curve (MC) Cobb angle improved 41 %; C7–center sacral vertical line, 75 %; C7–MC apex, 21 %; and T2–T12 kyphosis, 35 %. Trunk height increased 37 % and thoracic height 44 %. An additional amount of correction was obtained with posterior spinal instrumentation (±fusion), decreasing MC Cobb angle an additional 23 %; C7–apex, 16 %; and T2–T12 kyphosis, 10 %. There was no additional correction of thoracic height. Two years after posterior spinal instrumentation (±fusion), a mild-to-moderate amount of correction was lost: MC Cobb angle decreased 23 %; compensatory Cobb angle, 28 %; C7–CSVL, 24 %; C7–S1, 22 %; regional kyphosis, 31 %; thoracic kyphosis, 29 %; and trunk height, 27 %.

Conclusions

Among children with skeletal dysplasia and severe kyphosis, halo-gravity traction is well tolerated and safe. Most of the corrections in radiographic parameters were achieved with traction alone. Traction improves coronal balance, apical translation, thoracic height, and kyphosis. In this specific population, the potential for neurologic injury during corrective surgery is high. However, preoperative halo-gravity traction provides slow, progressive correction in a safe manner and avoided neurologic injury in these patients. This study did not compare patients without halo-gravity traction to patients with halo-gravity traction, therefore it cannot be concluded that going straight to instrumentation without traction will give a poorer radiographic result.

Level of evidence

IV.

     

Efficacy of perioperative halo-gravity traction for treatment of severe scoliosis (≥100°)

Background

There have been no standardized surgical options for severe scoliotic curvatures ≥100°. Halo-gravity traction is a viable option for surgical treatment of severe scoliosis. The aim of this study was to evaluate the efficacy and safety of perioperative halo-gravity traction for scoliosis curves ≥100° with respect to radiographic outcomes and clinical complications.

Methods

A total of 21 scoliosis patients with ≥100° curves (average 118.7°; range 100°-158°) with a minimum 2-year follow-up (average 41.8 months; range 24.0-97.0 months) who underwent spinal instrumented fusion using perioperative halo-gravity traction were analyzed. Diagnoses were neuromuscular scoliosis (n = 10), idiopathic (n = 9), and congenital (n = 2). In all, 15 patients were treated by the anterior release procedure followed by final posterior fusion and 6 patients by posterior fusion alone. Six patients had only preoperative traction preceding posterior fusion alone, 6 patients only staged traction between anterior release and final posterior fusion, and 9 patients had both preoperative traction preceding anterior release and staged traction preceding final posterior fusion. The average overall traction period in all patients was 67 days (range 10–78 days).

Results

Radiographic outcomes demonstrated 51.3% correction of the major Cobb angle, 40 mm correction of apical vertebral translation, 76 mm increase of T1-S1 length, and 20.7% increase of space available for lungs at the ultimate follow-up (all comparisons P < 0.05). Preoperative traction demonstrated 27.5% correction of the major curve Cobb angle, 51.5 mm increase of T1-S1 length, 14.9% increase of space available for the lungs (all comparisons P < 0.05). Staged traction after anterior release demonstrated 37.2% correction of the major curve Cobb angle, 26.1 mm correction of apical vertebral translation, 56.5 mm increase of T1-S1 length, 14.2% increase of space available for the lungs (all comparisons P < 0.05). There were only two patients with a pin-site problem, and one required débridement. There were no neurological deficits or clinical complications.

Conclusions

Scoliosis patients with ≥100° curves can be managed successfully by corrective fusion surgery concomitant with perioperative halo-gravity traction without significant complications.     

Surgery and survival outcomes of 22 patients with epidural spinal cord compression caused by thyroid tumor spinal metastases

Purpose

The aim of this study was to discuss the clinical presentation, imaging findings, treatments received, and outcome of therapies for patients with epidural spinal cord compression caused by thyroid spinal metastases, with the goal of emphasizing the importance of surgery in this setting and discussing therapeutic plan for treating these patients.

Methods

A total of 22 patients with spinal cord compression due to thyroid tumor spinal metastases who received surgery in our department were identified from 2004 to 2011. The series of 22 patients collected from our institution over the past 7 years was used to discuss treatment options for thyroid cancer spinal metastases on the basis of literature review and our own extensive experience.

Results

The mean age of the patients in this study was 57 years (range 37–78 years). The duration of the preoperative symptoms was 1–24 months, with an average of approximately 6 months. All patients attained improvement of at least one level of the Frankel classification after surgery. Two patients received more than one operation at our institution. Two patients died during follow-up, two patients had stable disease, and all other patients maintained a disease-free status during follow-up.

Conclusions

As thyroid tumor spinal metastases have a favorable prognosis, a radical therapeutic attitude should be considered in decision-making. Dorsal spinal decompression through curettage and stabilization can preserve or restore neurological function for most patients. For patients who have more than one metastatic lesion of the spine, surgeries can be sequentially performed based on the urgency of the case. In addition to treatment of primary disease, surgery and bisphosphonate treatment are the most important therapies for these patients.     

Measurement of volume-occupying rate of cervical spinal canal and its role in cervical spondylotic myelopathy

Purpose

To compare volume-occupying rate of cervical spinal canal between patients with cervical spondylotic myelopathy (CSM) and normal subjects, and to investigate its significance in cervical spine disease.

Methods

Spiral computed tomography (CT) scan (C4–C6 cervical spine unit) was performed in 20 normal subjects and 36 cases of CSM at a neutral position, and data were transferred to the Advantage Workstation Version 4.2 for assessment. Bony canal area and fibrous canal area in each cross section, and sagittal diameters of cervical spinal canal and cervical spinal body were measured. Volume-occupying rate of cervical spinal canal was calculated using MATLAB. Cervical spinal canal ratio and effective cervical spinal canal ratio were calculated, and Japanese Orthopaedic Association score was used to assess cervical spinal cord function.

Results

Volume-occupying rate of cervical spinal canal at a neutral position was significantly higher in CSM patients as compared to normal subjects (P < 0.01). There was no correlation between cervical spinal canal ratio and JOA score in CSM patients, with a Pearson’s correlation coefficient of 0.171 (P > 0.05). However, sagittal diameter of secondary cervical spinal canal, effective cervical spinal canal ratio and volume-occupying rate of cervical spinal canal were significantly associated to JOA score, with Pearson’s coefficient correlations of 0.439 (P < 0.05), 0.491 (P < 0.05) and ?0.613 (P < 0.01), respectively.

Conclusions

Volume-occupying rate of cervical spinal canal is an objective reflection of compression on cervical spine and spinal cord, and it is associated with cervical spinal cord function. These suggest that it may play a significant role in predicting the development of CSM.     

Noncontiguous double-level unstable spinal injuries

Purpose

Noncontiguous double-level unstable spinal injuries (NDUSI) are uncommon and have not been well described. In this study, we aimed to better understand the patterns of NDUSI, in order to recommend proper diagnostic and treatment methods, as well as to raise awareness among traumatologists about the possibility of these uncommon injuries.

Methods

A total of 710 consecutive patients with spine fractures were treated for >9 years since 2007 at a single regional trauma center. Of them, 18 patients with NDUSI were reviewed retrospectively.

Results

The incidence of NDUSI was 2.5 % of all spine fractures. In 17 of 18 patients (94.7 %), NDUSI was caused by a high-energy trauma. Nine patients (50.0 %) exhibited complete neurological deficit. Spinal cord injury occurred in the cranial injured region in all American Spinal Injury Association grade A cases. In one case, a second fracture was overlooked at the initial examination.

Conclusion

NDUSI are common in cases of high-energy trauma and should be taken into consideration at the initial examination. A second fracture may be easily overlooked because of the high frequency of concomitant severe spinal cord injury in the cranial injured region and/or loss of consciousness due to associated injuries. To avoid overlooking injuries, full spine computed tomography is useful at the initial examination. Operative reduction and internal fixation with instrumentation through a posterior approach is recommendable for cases of NDUSI. In elderly patients, a very rapid stabilizing surgery should be planned before aspiration pneumonia occurs or the pulmonary condition worsens.

     

Validation study of a clinical diagnosis support tool for lumbar spinal stenosis

Background

A clinical diagnosis support tool for lumbar spinal stenosis was developed by the Japanese Society for Spine Surgery and Related Research. However, the use of this tool has not yet been validated.

Methods

Patients with symptoms in the lower extremities and who visited the Department of Orthopedics initially were recruited to the study. Orthopedic physicians who were not spine specialists completed the support tools. Spine specialists examined the patients, made a diagnosis, and completed the lumbar spine examination sheet made for the study. The support tool and lumbar spine examination sheet were sent to a central panel comprising four panelists who then decided on a final diagnosis.

Results

In total, 118 patients were evaluated, including 62 males and 56 females. Lumbar spinal stenosis was diagnosed in 58 and nonlumbar spinal stenosis in 60 patients. The mean score in the lumbar spinal stenosis group was 12.2 points (median 13 points). In the nonlumbar spinal stenosis group, the mean score was 7.5 points (median 7 points). Sensitivity was 0.948, and specificity was 0.40.

Conclusions

Patients with lumbar spinal stenosis with a very low score were diagnosed with mild lumbar spinal stenosis, whereas nonlumbar spinal stenosis patients with a very high score were diagnosed as suffering from spine disease and needing special treatment by spine surgeons. Our results validate the use of the support tool for the diagnosis of lumbar spinal stenosis. Although the specificity observed in the present study was lower than that reported at development, we conclude that this support tool is useful for screening patients with lumbar spinal stenosis.     

Eosinophilic granuloma of spine in adults: a report of 30 cases and outcome

Background

Eosinophilic granuloma (EG) of the spine is rare, especially in adults. There had been few large and long-term studies reported in the literature. The management goals of this disease in adults are preservation of neurologic function, relief of pain and reconstruction of spinal stability. However, there are still controversies over appropriate management modality of eosinophilic granuloma.

Methods

Clinical manifestations, radiographic presentations, therapeutic outcomes and follow-up findings of 30 adults who were histiologically diagnosed with spinal eosinophilic granuloma, including 28 patients who received surgical treatment at our institutions from 1985 to 2008 were reviewed retrospectively.

Results

There were 25 males and five females with a mean age of 34.5 years (range, 18–71 years). The post-operative follow-up period ranged from 2 to 22.4 years (mean, 8.3 years). Neurologic deficits developed in 21 patients, apparent kyphosis developed in four cases. In contrast to the classic feature of vertebra plana in children, we found that more severe lesions often led to asymmetric collapse in adult patients and only three patients presented with vertebra plana. Thirty-three vertebral lesions distributed throughout the spine column. Twenty-one lesions were in cervical spine, seven in the thoracic spine and five in the lumbar spine. Twenty-eight adult patients underwent surgical resection with or without chemotherapy or radiotherapy, and four (13.3%) patients had recurrence after surgery. No patient in our series died.

Conclusions

The onset of spinal EG is insidious and mainly presents as osteolytic destruction. There is a particular high prevalence of lesions in the cervical spine and more severe lesions often led to asymmetric collapse. As the skeleton of adults is well-developed and the epiphysis has stopped growing, individualized management including surgical intervention should be considered in adult patients with spinal EG who present with neurological damage and spinal instability.     

X-Ray assessment of the effect of pedicle screw on vertebra and spinal canal growth in children before the age of 7 years

Purpose

To determine the reliability of pedicle screws placed in children younger than 7 years of age, and to evaluate the effect of pedicle screw insertion on further growth of the vertebra and spinal canal.

Methods

A retrospective study of 35 consecutive patients through Jan 2003–Dec 2010 for congenital scoliosis in <7 years children was performed at one spine center. Patients undergoing pedicle screw instrumentation of at least two levels, which had been followed-up for at least 24 months were included. Measurements were performed in instrumented and adjacent non-instrumented levels. The effect of pedicle screw insertion on further growth was evaluated.

Results

The average age at surgery was 4.4 year (53 months, range, 23–84 months). 190 segments in 35 patients met the inclusion criteria. 77 segments had no screws and 113 had at least one screw. There was a significant difference between the pre-operative and final follow-up values of the measurement of spinal canal and vertebral body parameters (P < 0.001). No significant difference existed between growth rates of vertebral bodies and the sagittal diameters of spinal canal with or without screws. The growth rates of vertebral bodies in lumbar spine were higher than in thoracic spine in both instrumented and adjacent groups.

Conclusion

Pedicle screw instrumentation does not cause a retardation effect on the development of vertebral bodies and the spinal canal in children at an early age. It is a safe and reliable procedure to achieve a stable fixation.     

Tadpole system as new lumbar spinal instrumentation

Background

There have been reports of serious complications associated with pedicle screw fixation, including nerve root injuries caused by accidental screw insertion. We have developed a new system of lumbar spinal instrumentation that we call Tadpole system^®. The purposes of this report were to show the results of a biomechanical study and the short-term outcome of a clinical study, as well as to determine the usefulness of this system.

Methods

The Tadpole system^® lumbar spinal fusion is a hook-and-rod system according to which the spine is stabilized using 2 sets of 2 spinous processes each that are held in place by 4 hooks tandemly connected to a rod. The biomechanical study was done using 5 human lumbar cadaveric spines, and the range of motion (ROM) was examined in a non-treatment model, an injured model, a pedicle screw fixation model and a Tadpole system^® model. For the short-term clinical study the Tadpole system^® was used in 31 patients, and the factors analyzed were operation time, time required for spinal instrumentation, amount of intraoperative bleeding, postoperative improvement rate of the Japanese Orthopaedic Association (JOA) score for lumbar spinal disorders, instrumentation failure, spinous process fracture, spinal fluid leakage, nerve root injury, postoperative infection, and bone fusion 2 years after the operation.

Results

The ROM in the Tadpole system^® model was slightly bigger than that in the pedicle screw fixation model, but smaller than that in the normal control model. These biomechanical data indicated that the Tadpole system^® provided fairly good stability. The mean operation time was 79 min, the mean time required for spinal instrumentation was 8 min, and the mean amount of intraoperative bleeding was 340 mL. The mean postoperative improvement rate of JOA score was 70.9 ± 24.8%. Instrumentation failure (dislocation of a hook) occurred in one patient, and none of the patients developed spinous process fracture, spinal fluid leakage, nerve root injury, or postoperative infection. Two years after the operation, bone union was confirmed in 29 of the 31 patients (93.5%).

Conclusion

We conclude that this system is a useful, easy-to-use and safe spinal instrumentation technique for lumbar fusion surgery.