Cervical spine deformity associated with resection of spinal cord tumors

Influence of the type of atlantoaxial dislocation secondary to os odontoideum on sagittal alignment and balance of the subaxial cervical spine after posterior atlantoaxial fusion

OBJECTIVE

This retrospective study aims to investigate the effect of the type of atlantoaxial dislocation due to os odontoideum on the sagittal alignment and balance of the cervical spine after posterior atlantoaxial fusion.

METHODS

Data of 48 consecutive patients who underwent posterior C1-C2 fusion to treat atlantoaxial dislocation/instability due to os odontoideum were retrospectively reviewed. Radiographic variables, namely the T1 slope (T1S), C1-C2 angle, C2-C7 angle, C1-C2 sagittal vertical axis (SVA), C2-C7 SVA, and modified atlas-dens interval (MADI), were measured preoperatively, immediate postoperatively, and at final follow-up. Patients were divided into three groups based on the preoperative MADI. Differences within and between groups in radiographic variables and relationships between the investigated variables were analyzed.

RESULTS

The MADI was correlated with the preoperative to postoperative changes in the C1-C2 angle (r = 0.776, P < 0.05) and C2-C7 angle (r = - 0.357, P < 0.05). In the group with anterior atlantoaxial dislocation, the C1-C2 angle and C2-C7 SVA were significantly enlarged at final follow-up (P < 0.05), while the C2-C7 angle was significantly reduced (P < 0.05). The changes in C1-C2 angle and C2-C7 angle were opposite between the posterior group and the anterior dislocation group.

CONCLUSION

The direction/type of atlantoaxial subluxation correlates with the changes in lower cervical curvature after atlantoaxial fusion. Patients with atlantoaxial posterior dislocation and atlantoaxial instability are less likely than those with atlantoaxial anterior dislocation to develop loss of lordosis after posterior atlantoaxial fusion.

Predictors for spinal deformity following resection of intramedullary tumor via posterior approach: a systematic review and meta-analysis

PURPOSE

The present study aimed to identify the clinical predictive factors for worsened spinal deformity (SD) following surgical resection via posterior approach for primary intramedullary tumors.

METHODS

A systematic search was performed using PubMed, Web of Science, and Scopus databases to extract potential references. Observational studies reporting predictive factors for worsened SD following surgical resection via posterior approach for primary intramedullary tumors were included. The odds ratio (OR) was calculated for dichotomous parameters.

RESULTS

Four retrospective cohort studies were included in the meta-analysis. They were comprised of two groups of patients; those who developed SD (n = 87) and those who did not (n = 227). For patients with IMSCTs, age under 25 years as well as age under 13 years were the demographic variables associated with postoperative SD (odds ratio [OR] 3.92; p = 0.0002 and OR 4.22; p = 0.003). In both the fusion and the non-fusion subgroups, preoperative spinal deformity strongly predicted postoperative SD (OR 11.94; p < 0.001), with the risk highly elevated among the non-fusion patients (OR 24.64; p < 0.0002). Thoracolumbar junction involvement was also found to be a predictor of postoperative SD for patients with IMSCT (OR 2.89; p = 0.02).

CONCLUSION

This study highlights the importance of considering age, preoperative spinal deformity, and thoracolumbar junction involvement as predictors of postoperative spinal deformity following surgical resection for IMSCT. These findings may provide guidance for the management of these patients, including the development of preoperative planning strategies and the selection of the most appropriate surgical approach for high-risk patients.

The Relationship Between Cervical Sagittal Balance and Type of Atlantoaxial Dislocation Secondary to Os Odontoideum

OBJECTIVE

To analyze the effect of cervical sagittal balance on the direction and type of atlantoaxial dislocation.

METHODS

Data of 55 patients seen at our hospital for atlantoaxial instability/dislocation caused by os odontoideum were reviewed. Radiographic variables, including T1 slope (T1S), C1-C2 angle, C2-C7 angle, C1-C2 sagittal vertical axis (SVA), C2-C7 SVA, and atlanto-dens interval (ADI), were measured preoperatively. Patients were divided into three groups according to ADI: anterior atlantoaxial dislocation, atlantoaxial instability, and posterior atlantoaxial dislocation. Differences within and between groups in radiographic variables and relationships between the investigated variables were analyzed.

RESULTS

ADI was strongly negatively associated with C1-C2 angle (r = -0.805, P < 0.05); whereas ADI had a medium-strength positive relationship with C2-C7 angle (r = 0.425, P < 0.05) and a medium-strength negative relationship with C2-C7 SVA (r = -0.411, P < 0.05). However, ADI was not significantly correlated with T1 slope (r = -0.092, P > 0.05).

CONCLUSIONS

The type and direction of atlantoaxial dislocation is closely associated with cervical sagittal balance. C2-C7 SVA is an important factor in assessing the direction of atlantoaxial subluxation secondary to os odontoideum. ADI decreases with increasing C2-C7 SVA. The larger the C2-C7 SVA, the more likely the atlantoaxial dislocation is to be posterior.

Long-term Follow-up Results of Reconstructive Laminoplasty With L-shaped Leibinger Mini-plate for Posterior Approach in the Treatment of Intraspinal Tumor Surgery

OBJECTIVE

Laminoplasty using mini-plates is one of the most common surgical techniques in surgery for intraspinal pathologies. However, limited are present in the literature. The aim of this study was to determine its long-term clinical and radiologic outcome, specifically using an L-shaped mini-plate.

METHODS

Patients who underwent surgery for spinal intradural pathology from January 2008 to December 2019 were retrospectively reviewed. Those who received laminoplasty using the Leibinger mini-plate and were followed for more than 2 years were included. Patient demographics and clinical and radiographic data were reviewed and analyzed. A total of 117 patients (male:female = 47:70; mean age 50.9 years, range 16-92 years) were included, and mean follow-up period was 50.3 months (range 24-151 months).

RESULTS

The most common pathology was schwannoma (n = 66, 56.4%) followed by meningioma (n = 30, 25.6%). Gross total resection was achieved in 82.9% (n = 97). Clinical outcomes at last follow-up were mostly good and excellent (n = 95, 81.2%). Computed tomography at the postoperative 1-year follow-up were available in 32 patients (27.4%) and the overall fusion rate was 89.3% (50 of 56 laminae). The fusion rate was significantly lower in the cervical spine compared to other locations (50% vs. thoracic [100%], lumbar [85.7%], P < 0.002). No displacement of laminae or postoperative spinal deformity were observed throughout the follow-up.

CONCLUSIONS

Laminoplasty using L-shape Leibinger mini-plates had an 89.3% fusion rate, and no displacement of the re-attached laminae was observed. We think it is a safe and feasible option in surgeries for intraspinal pathologies.

Role of Posterior Longitudinal Ligament Complex in Spinal Deformity Secondary to Surgical Resection of the Intradural Tumor

OBJECTIVE

In most cases, complete resection of the intradural tumor is accompanied by long-term neurological complications. Postoperative spinal deformity is the most common complication after surgical resection of intradural tumors, and posterior longitudinal ligament complex (PLC) plays an important role in postoperative spinal deformity. In this study, we investigated the role of PLC in spinal deformity after the surgical treatment of intradural tumors.

METHODS

We analyzed the data of 218 consecutive patients who underwent intradural tumor resection from 2000 to 2018 in this retrospective study. Before 2010, patients underwent laminoplasty without maintaining the integrity of PLC (laminoplasty group, n = 155). After 2010, patients performed single-port laminoplasty to maintain the integrity of PLC (laminoplasty retain posterior ligament complex group, n = 63). The score of quality of life, painful cortex, spinal cord movement, progressive kyphosis or scoliosis, perioperative morbidity, and neurological results were analyzed in the laminoplasty group and laminoplasty retain posterior ligament complex group. The distributed variable was shown as mean ± standard deviation and an independent t-test or one-way analysis of variance was calculated.

RESULTS

There are 155 patients (71.1%) included in the laminoplasty group, and 63 patients (28.9%) in the laminoplasty retain posterior ligament complex group. The average age of patients was 42 ± 2.3 years, and the average modified McCormick score was 2. There were 158 (72.4%) patients with intramedullary tumors and 115 (52.7%) patients with extramedullary tumors. The length of hospital stays (8 days vs. 6 days; p = 0.023) and discharge to inpatient rehabilitation (48.4% vs. 26.9%; p = 0.012) were significantly lower in the laminoplasty retain posterior ligament complex group than the laminoplasty group. There was no significant difference in the risk of progressive deformity between the two groups at 18 months after surgery (relative risk 0.12; 95% confidence interval [CI] 0.43-1.25; p = 0.258) and at 20 months after surgery (relative risk 0.24; 95% CI 0.21-2.1).

CONCLUSION

Laminoplasty retains posterior ligament complex showed no impact on the spinal deformities compared with laminoplasty, but significantly improved the postoperative spinal activity, alleviated pain symptoms, and reduced hospital recovery time.

Primary epidural sporadic Burkitt lymphoma in a 3-year-old: Case report and literature review

Background:

Burkitt lymphoma (BL) is a common tumor of childhood that usually arises in the abdomen or pelvis in its sporadic form. In a minority of cases, BL can present with CNS involvement, usually as a secondary site. Rarely, BL can arise primarily in the epidural space and present with back pain, or less commonly, acute myelopathy. This presentation is a surgical emergency and requires vigilant management.

Case Description:

We describe a case of pediatric BL arising primarily within the epidural space and presenting with progressive difficulty walking in a 3-year-old boy. Progression to complete inability to walk, absent lower extremity deep tendon reflexes, and new urinary incontinence prompted MRI of the spine, which showed a lesion extending from T5 to T10 and wrapping around the anterior and posterior portions of the spine with evidence of spinal cord compression. The patient underwent decompressive laminectomies from T5 to T10 and partial debulking of the posterior portions of the tumor. Microscopic examination showed a prominent “starry sky” pattern with abundant mitotic figures. Immunohistochemistry confirmed the diagnosis of BL. The patient is 10 months post-op and continues to undergo chemotherapy with partial neurologic improvement. He was free of recurrence 10 months post-operative.

Conclusion:

This appears to be the youngest described patient presenting with acute myelopathy in primary paraspinal BL. Management should include surgical decompression of the spinal cord followed by one of the various described chemotherapeutic regimens. Preoperative staging and neurologic function correlate with prognosis.

A 540° posterior-anterior-posterior approach for 360° fused rigid severe cervical kyphosis: patient series

BACKGROUND

Treatment of severe rigid 360° fused cervical kyphosis (CK) is challenging and often requires a combined approach for ankylosis release, establishment of sagittal balance, and fixation with fusion.

OBSERVATIONS

Four patients with iatrogenic 360° fused severe rigid CK (Cobb angle ≥40°) were enrolled for this retrospective analysis. All patients in the case series were female, with an average age of 27 years. All patients previously underwent posterior laminectomy/laminoplasty and cervical tumor resection when they were children (13–17 years). They underwent correction surgery with a 540° posterior-anterior-posterior approach. Preoperative and final follow-up radiography and computed tomography (CT) were used to evaluate kyphosis correction, internal fixation implants, and bone fusion. The preoperative and final follow-up average C2–7 Cobb angles were −32.4° ± 12.0° and 5.3° ± 7.1°, respectively. Preoperative and final follow-up CK angles averaged −47.2° ± 7.4° and −0.9° ± 16.1°, respectively. The mean correction angle was 46.3° ± 9.6°. At final follow-up, CT showed stable fixation and solid bone fusion.

LESSONS

The rare iatrogenic severe kyphosis with 360° ankylosis requires a combined approach. The 540° posterior-anterior-posterior approach can completely release the bony fusion, and the CK can be corrected using an anterior plate. This technique can achieve good results and is an effective strategy.

Surgical treatment and outcomes of intramedullary tumors by minimally invasive approach

Intramedullary tumors are uncommon neoplasms which, without treatment, can cause neurologic morbidity or mortality. The goal of the treatment is complete surgical resection with a minimally invasive approach while preserving neurological status and also spinal stability. Out of 1972 patients with tumors of the spinal canal treated between 1994 and 2017, 168 intramedullary tumors of 417 intradural tumors have been presented. All patients had undergone one surgical resection. The mean age is 43 ± 12 years (range 11-67 years). Tumors were subdivided into 4 groups: cervically located-tumors (n = 43), cervicothoracic-region-tumors (n = 32), thoracic-region-tumors (n = 57), and lumbosacral-region-tumors (n = 36). The mean follow-up time was 37 ± 29 months. Gross-total resection rate was higher in cervical located intramedullary tumors compared to the thoracic intramedullary tumors. Cervical intramedullary tumors showed better postoperative functional outcome than the thoracic intramedullary lesions. In intramedullary tumors, extending more than 3 spinal segments, postoperative worsening was significantly increased. A minimally invasive approach (the bilateral decompression via unilateral hemilaminectomy) was used to remove the tumor while preserving spinal stability. Perioperative permanent morbidity was very low. Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Patients with thoracic intramedullary tumors and tumor extension of more than three segments were at a higher risk for permanent morbidity. The minimally invasive approach allowed complete removal of the intramedullary tumors, and adequate preservation of vertebral stability while providing a good postoperative course.

Incidence and predictors of kyphotic deformity following resection of cervical intradural tumors in adults: a population-based cohort study

BACKGROUND

The first line of treatment for most cervical intradural tumors is surgical resection through laminotomy or laminectomy. This may cause a loss of posterior pulling force leading to kyphosis, which is associated with decreased functional outcome. However, the incidence and predictors of kyphosis in these patients are poorly understood.

OBJECT

To assess the incidence of posterior fixation (PF), as well as predictors of radiological kyphosis, following resection of cervical intradural tumors in adults.

METHODS

A population-based cohort study was conducted on adult patients who underwent intradural tumor resection via cervical laminectomy with or without laminoplasty between 2005 and 2017. Primary outcome was kyphosis requiring PF. Secondary outcome was radiological kyphotic increase, measured by the change in the C2-C7 Cobb angle between pre- and postoperative magnetic resonance images.

RESULTS

Eighty-four patients were included. Twenty-four percent of the tumors were intramedullary, and the most common diagnosis was meningioma. The mean laminectomy range was 2.4 levels, and laminoplasty was performed in 40% of cases. No prophylactic PF was performed. During a mean follow-up of 4.4 years, two patients (2.4%) required delayed PF. The mean radiological kyphotic increase after surgery was 3.0°, which was significantly associated with laminectomy of C2 and C3. Of these, C3 laminectomy demonstrated independent risk association.

CONCLUSIONS

There was a low incidence of delayed PF following cervical intradural tumor resection, supporting the practice of not performing prophylactic PF. Kyphotic increase was associated with C2 and C3 laminectomy, which could help identify at-risk patients were targeted follow-up is indicated.

Cervical meningioma resection including the inner dura through an open-door laminoplasty using hydroxyapatite spacers: A case report

Background:

The ideal surgery for spinal cord tumors is complete resection to prevent recurrence. However, it should be accomplished safely/effectively without risking increased morbidity. Here, we report a cervical meningioma that was totally resected, including the inner dura, through a laminoplasty performed with hydroxyapatite (HA) spacers.

Case Description:

A 61-year-old Asian male presented with a symptomatic intradural extramedullary C4-C6 cervical meningioma. At surgery, this required resection of the inner dural layer through an open-door laminoplasty. Preservation of the outer dural layer facilitated a watertight closure and the avoidance of a postoperative cerebrospinal fluid (CSF) fistula. Notably, the laminoplasty utilized HA spacers which were magnetic resonance (MR) compatible allowing for future follow-up studies to evaluate for tumor recurrence. At 5-year follow-up, the tumor had not recurred, the patient was asymptomatic, and alignment was maintained.

Conclusion:

Gross total resection of an intradural extramedullary C4-C6 cervical meningioma was performed with removal of just the inner dural layer. Preservation of the outer dural layer allowed for a watertight closure and the avoidance of a postoperative CSF leak. Further, laminoplasty using HA spacers allowed for successful tumor resection, adequate fusion/stabilization, while not interfering with future MR studies (e.g., HA MR compatible).

Validation Study of Rajasekaran's Kyphosis Classification System: Do We Clearly Understand Single- and Two-Column Deficiencies?

Study Design

Multicenter validation study.

Purpose

To evaluate the inter-rater reliability of Rajasekaran’s kyphosis classification through a multicenter validation study.

Overview of Literature

The classification of kyphosis, developed by Rajasekaran, incorporates factors related to curve characteristics, including column deficiency, disc mobility, curve magnitude, and osteotomy requirements. Although the classification offers significant benefits in determining prognosis and management decisions, it has not been subjected to multicenter validation.

Methods

A total of 30 sets of images, including plain radiographs, computed tomography scans, and magnetic resonance imaging scans, were randomly selected from our hospital patient database. All patients had undergone deformity correction surgery for kyphosis. Twelve spine surgeons from the Asia-Pacific region (six different countries) independently evaluated and classified the deformity types and proposed their surgical recommendations. This information was then compared with standard deformity classification and surgical recommendations.

Results

The kappa coefficients for the classification were as follows: 0.88 for type 1A, 0.78 for type 1B, 0.50 for type 2B, 0.40 for type 3A, 0.63 for type 3B, and 0.86 for type 3C deformities. The overall kappa coefficient for the classification was 0.68. Regarding the repeatability of osteotomy recommendations, kappa values were the highest for Ponte’s (Schwab type 2) osteotomy (kappa 0.8). Kappa values for other osteotomy recommendations were 0.52 for pedicle subtraction/disc-bone osteotomy (Schwab type 3/4), 0.42 for vertebral column resection (VCR, type 5), and 0.30 for multilevel VCRs (type 6).

Conclusions

Excellent accuracy was found for types 1A, 1B, and 3C deformities (ends of spectrum). There was more variation among surgeons in differentiating between one-column (types 2A and 2B) and two-column (types 3A and 3B) deficiencies, as surgeons often failed to recognize the radiological signs of posterior column failure. This failure to identify column deficiencies can potentially alter kyphosis management. There was excellent consensus among surgeons in the recommendation of type 2 osteotomy; however, some variation was observed in their choice for other osteotomies.

Risk factor analysis for progressive spinal deformity after resection of intracanal tumors─ a retrospective study of 272 cases

BACKGROUND

Progressive spinal deformity has become a well-recognized complication of intracanal tumors resection. However, the factors affecting post-operative spinal stability remain to be further research. Here, we described the current largest series of risk factors analysis for progressive spinal deformity following resection of intracanal tumors.

METHODS

We retrospectively analyzed the medical records of the patients with resection of intracanal tumors between January 2009 and December 2018. All patients who underwent resection of intracanal tumors performed regular postoperative follow-up were identified and included in the study. Clinical, radiological, surgical, histopathological, and follow-up data were collected. The incidence of postoperative progressive kyphosis or scoliosis was calculated. The statistical relationship between postoperative progressive spinal deformity and radiographic, clinical, and surgical variables was assessed by using univariate tests and multivariate logistic regression analysis.

RESULTS

Two hundred seventy-two patients (mean age 42.56 ± 16.18 years) with median preoperative modified McCormick score of 3 met the inclusion criteria. Among them, 7(2.6%)patients were found to have spinal deformity preoperatively, and the extent of spinal deformity in these 7 patients deteriorated after surgery. 36 (13.2%) were new cases of postoperative progressive deformity. The mean duration of follow-up was 21.8 months (median 14 months, range 6-114 months). In subsequent multivariate logistic regression analysis, age ≤ 18 years (p = 0.027), vertebral levels of tumor involvement (p = 0.019) and preoperative spinal deformity(p = 0.008) was the independent risk factors (p < 0.05), increasing the odds of postoperative progressive spinal deformity by 3.94-, 0.69- and 27.11-fold, respectively.

CONCLUSIONS

The incidence of postoperative progressive spinal deformity was 15.8%, mostly in these patients who had younger age (≤18 years), tumors involved in multiple segments and preoperative spinal deformity. The risk factors of postoperative progressive spinal deformity warrants serious reconsideration that when performing resection of spinal cord tumors in these patients with such risk factors, the surgeons should consider conducting follow-ups more closely, and when patients suffering from severe symptoms or gradually increased spinal deformity, surgical spinal fusion may be a more suitable choice to reduce the risk of reoperation and improve the prognosis of patients.

Benign Intradural and Paraspinal Nerve Sheath Tumors: Advanced Surgical Techniques

Traditional surgical techniques for benign intradural and paraspinal nerve sheath tumors often consisted of open posterior approaches. However, these were limited by the morbidity of open surgery. In addition, iatrogenic instability is often required for total resection of larger or laterally located tumors, thus necessitating the use of additional hardware for spinal fusion. Advances in surgical techniques and technologies have allowed for a plethora of minimally invasive approaches throughout the cervical, thoracic, and lumbar regions. These approaches and their particular applications for the resection of benign peripheral nerve sheath tumors are described, with special attention to modern surgical strategies.

Risk factor analysis of progressive spinal deformity after resection of intramedullary spinal cord tumors in patients who underwent laminoplasty: a report of 105 consecutive cases

OBJECTIVE

Laminoplasty has been used in recent years as an alternative approach to laminectomy for preventing spinal deformity after resection of intramedullary spinal cord tumors (IMSCTs). However, controversies exist with regard to its real role in maintaining postoperative spinal alignment. The purpose of this study was to examine the incidence of progressive spinal deformity in patients who underwent laminoplasty for resection of IMSCT and identify risk factors for progressive spinal deformity.

METHODS

Data from IMSCT patients who had undergone laminoplasty at Beijing Tsinghua Changgung Hospital between January 2014 and December 2016 were retrospectively reviewed. Univariate tests and multivariate logistic regression analysis were used to assess the statistical relationship between postoperative spinal deformity and radiographic, clinical, and surgical variables.

RESULTS

One hundred five patients (mean age 37.0 ± 14.5 years) met the criteria for inclusion in the study. Gross-total resection (> 95%) was obtained in 79 cases (75.2%). Twenty-seven (25.7%) of the 105 patients were found to have spinal deformity preoperatively, and 10 (9.5%) new cases of postoperative progressive deformity were detected. The mean duration of follow-up was 27.6 months (SD 14.5 months, median 26.3 months, range 6.2-40.7 months). At last follow-up, the median functional scores of the patients who did develop progressive spinal deformity were worse than those of the patients who did not (modified McCormick Scale: 3 vs 2, and p = 0.04). In the univariate analysis, age (p = 0.01), preoperative spinal deformity (p < 0.01), extent of tumor involvement (p < 0.01), extent of abnormal tumor signal (p = 0.02), and extent of laminoplasty (p < 0.01) were identified as factors associated with postoperative progressive spinal deformity. However, in subsequent multivariate logistic regression analysis, only age ≤ 25 years and preoperative spinal deformity emerged as independent risk factors (p < 0.05), increasing the odds of postoperative progressive deformity by 4.1- and 12.4-fold, respectively (p < 0.05).

CONCLUSIONS

Progressive spinal deformity was identified in 25.7% patients who had undergone laminoplasty for IMSCT resection and was related to decreased functional status. Younger age (≤ 25 years) and preoperative spinal deformity increased the risk of postoperative progressive spinal deformity. The risk of postoperative deformity warrants serious reconsideration of providing concurrent fusion during IMSCT resection or close follow-up after laminoplasty.

Postoperative Cervical Sagittal Realignment Improves Patient-Reported Outcomes in Chronic Atlantoaxial Anterior Dislocation

BACKGROUND

Chronic atlantoaxial anterior dislocation (AAD) not only results in myelopathy, but dislocation-related kyphosis also results in cervical malalignment, which permanently affects neck function and patient-reported outcomes (PROs).

OBJECTIVE

To investigate the effect of kyphotic correction on realigning cervical spine and independent cervical alignment parameters, which may be correlated with an improvement of PROs.

METHODS

The study included 21 patients with chronic AAD-related kyphosis who underwent C1-2 reduction and correction surgery. Radiographic parameters were measured to assess cervical realignment preoperatively and postoperatively. Neck disability index (NDI), short form 12 physical component summary (SF-12 PCS), and Japanese Orthopaedic Association (JOA) scores were recorded to reveal changes in PROs. The independent parameters correlated with the improvements of PROs were analyzed.

RESULTS

Of the radiographic parameters, the C1-2 Cobb angle, the C2-7 Cobb angle, thoracic inlet angle, cervical tilt, and T1 slope were significantly changed from -4.0° ± 16.2°, -29.2° ± 11.2°, 73.1° ± 13.3°, 30.4° ± 8.5°, and 29.1° ± 8.8° preoperatively to -13.5° ± 8.1° (P = .005), -18.0° ± 12.0° (P < .001), 67.1° ± 11.6° (P = .042), 23.1° ± 10.3° (P = .007), and 24.0° ± 7.0° (P = .011) at last follow-up, respectively. NDI, JOA, and SF-12 PCS scores were significantly improved postoperatively. The C1-2 Cobb angle was an independent parameter correlated with the improvements in SF-12 PCS, NDI, and JOA scores.

CONCLUSION

Correction and reduction surgery can realign cervical spine in chronic AAD patients. The C1-2 Cobb angle was an independent parameter correlated with the improvements of PROs.

A Classification for Kyphosis Based on Column Deficiency, Curve Magnitude, and Osteotomy Requirement

BACKGROUND

There is a lack of a classification system providing uniformity in description and guiding management decisions for kyphotic spinal deformities. We developed such a classification based on column deficiency, flexibility of disc spaces, curve magnitude, and correlation with the corrective osteotomy required.

METHODS

A classification was developed based on analysis of 180 patients with thoracolumbar kyphosis requiring osteotomy. The deformity was classified as Type I if the anterior and posterior columns were intact (IA indicated mobile disc spaces and IB, ankylosed segments). Type II indicated deficiency of only 1 column (IIA = anterior column and IIB = posterior column). Type III indicated deficiency of both columns (IIIA = kyphosis of ≤60°, IIIB = kyphosis of >60°, and IIIC = buckling collapse). A prospective analysis of 76 patients was performed to determine interobserver variability and the ability of the classification to guide selection of osteotomies of increasing complexity, including the Ponte osteotomy, pedicle subtraction osteotomy, disc bone osteotomy, single vertebrectomy, multiple vertebrectomies, and anterior in situ strut fusion procedure.

RESULTS

The mean age of the 76 patients was 21.2 years, the mean kyphosis was 69.9° (range, 26° to 120°), and the mean follow-up duration was 30 months. Six deformities were classified as IA, 5 as IB, 5 as IIA, 2 as IIB, 13 as IIIA, 35 as IIIB, and 10 as IIIC. Four surgeons classifying the deformities had a high agreement rate (kappa = 0.83), with the highest agreement for Types IA, IB, and IIIB. A correlation between the type of deformity and the osteotomy performed demonstrated that the classification could indicate the type of osteotomy required. All 18 patients with Type-I or II kyphosis were treated with Ponte, pedicle subtraction, or disc bone osteotomy. Forty-three (90%) of the 48 patients with Type IIIA or IIIB underwent vertebrectomy (single in 27 [56%] and multiple in 16 [33%]), and only 5 (10%) underwent disc bone osteotomy. Seven of the 10 patients with Type-IIIC kyphosis were treated with multiple vertebrectomies, with 5 of them needing preoperative halo gravity traction; the other 3 patients underwent an anterior in situ strut fusion procedure.

CONCLUSIONS

The proposed classification based on the morphology of column deficiency, flexibility, and curve magnitude demonstrated a high interobserver agreement and ability to guide selection of the appropriate osteotomy.

CLINICAL RELEVANCE

A novel classification system for kyphosis based on spinal column deficiency, flexibility of disc spaces, and curve magnitude would bring uniformity in management and help guide surgeons in the choice of the appropriate corrective osteotomy.

Instrumented fusion for spinal deformity after laminectomy or laminoplasty for resection of intramedullary spinal cord tumors in pediatric patients

OBJECTIVE Spinal deformity has become a well-recognized complication of intramedullary spinal cord tumor (IMSCT) resection. In particular, laminectomy can result in biomechanical instability caused by loss of the posterior tension band. Therefore, laminoplasty has been proposed as an alternative to laminectomy. Here, the authors describe the largest current series of pediatric patients who have undergone laminoplasty for IMSCT resection and investigate the need for surgical fusion after both laminectomy and laminoplasty. METHODS The medical records of pediatric patients who underwent resection of an IMSCT at a single institution between November 2003 and May 2014 were reviewed retrospectively. Demographic, clinical, radiological, surgical, histopathological, and follow-up data were collected. RESULTS Sixty-six consecutive patients underwent resection of an IMSCT during the study period. Forty-three (65%) patients were male. The patients had a median age of 12.9 years (interquartile range [IQR] 7.2-16.5 years) at the time of surgery. Patients typically presented with a tumor that involved the cervical and/or thoracic spine. Nineteen (29%) patients underwent laminectomy, and 47 (71%) patients underwent laminoplasty. Patients in each cohort had a similar rate of postoperative deformity. Overall, 10 (15%) patients required instrumented spinal fusion for spinal deformity. Four patients required revision of the primary fusion. CONCLUSIONS These findings show that among pediatric patients with an IMSCT, postoperative surgical fusion rates remain high, even after laminoplasty. Known risk factors, such as the age of the patient, location of the tumor, and the number of involved levels, might play a larger role than replacement of the laminae in determining the rate of surgical fusion after IMSCT resection.

Risk factor analysis of kyphotic malalignment after cervical intramedullary tumor resection in adults

OBJECTIVE

A number of studies have reported that surgery for cervical intramedullary tumors via the posterior approach can result in postoperative sagittal malalignment of the cervical spine; however, the risk factors remain unclear. The purpose of this study was to investigate the changes in cervical spinal alignment after surgery for cervical intramedullary tumors in adults and to elucidate the risk factors for cervical spinal sagittal misalignment.

METHODS

Data for the period from April 2001 to December 2011 for all adults who had undergone surgery for cervical intramedullary spinal cord tumors at a single institution were retrospectively analyzed to determine the postoperative changes in cervical spine alignment. Patients younger than 20 years of age and those who required postoperative radiotherapy were excluded from the study. Patients were divided into 2 groups according to tumor location: upper tumor (U) group, in which the central region of the tumor was above the C-5 level; and lower tumor (L) group, in which the central region of the tumor was at or below the C-5 level. Changes in alignment of the cervical spine were measured on plain lateral radiographs. Data on atrophy of the deep extensor muscles (DEMs), tumor location, detachment of the DEMs from the C-2 spinous process, the C2–7 angle before surgery, patient age at surgery, tumor histology, patient sex, tumor size, and number of laminae affected were reviewed for each patient, and the correlation of each of these factors with cervical spinal malalignment was evaluated using statistical analysis.

RESULTS

The 54 adults eligible for analysis had a mean age of 49.1 years. Ependymoma was the most common cervical intramedullary tumor (63.0%) in this series. In the tumor location U group, the kyphotic angle of the C2–7 spinal segments increased after surgery (−5.8° ± 2.8°). In contrast, in the L group, the C2–7 lordotic angle increased after surgery (6.4° ± 2.6°). In the univariate analysis, atrophy of the DEMs, detachment of the DEMs from the C-2 spinous process, and an upper cervical location of the tumor were identified as factors significantly correlated with the development of cervical spinal kyphosis after surgery. Multiple linear regression analysis revealed the following as risk factors for kyphotic change of the cervical spine after surgery: 1) atrophy of the DEMs after surgery (β = −0.54, p < 0.01), and 2) detachment of the DEMs from the C-2 spinous process (β = −0.37, p < 0.01).

CONCLUSIONS

Atrophy of the DEMs after surgery and detachment of the DEMs from the C-2 spinous process are directly related to the risk of cervical spinal kyphosis after surgery for cervical intramedullary tumors in adults. Therefore, preservation of the DEMs, especially those attached to the C-2 spinous process, is important for the prevention of kyphotic malalignment of the cervical spine after surgery for intramedullary tumors.

Keyhole approaches to intradural pathologies

OBJECTIVE

Spinal tumors account for 2%–4% of all tumors of the central nervous system and can be intramedullary, intradural extramedullary, or extradural. In the past, wide approaches were used to obtain safe access to these tumors, as complete resection is the goal in treating most tumor entities. To reduce surgical complications due to large skin incisions and destabilizing laminectomies, minimally invasive approaches were established. In this study, the authors share their experience with mini-open approaches to intradural tumor pathologies.

METHODS

The authors retrospectively reviewed cases involving patients with intramedullary and intradural extramedullary lesions treated between 2009 and 2016. They present their surgical mini-open approach to the spinal cord as well as unique characteristics, key steps, and postsurgical complications for specific tumor subgroups (meningioma, neuroma, and intramedullary tumors).

RESULTS

A total of 245 intradural tumors were surgically treated during the study period. Of these lesions, 151 were intradural extramedullary meningiomas (n = 79) or neuromas (n = 72). Nine (12.5%) of the neuromas were dumbbell neuromas. Ninety-four tumors were intramedullary. The mean age of the patients was 51.4 years, and 53.9% were female. The mean duration of follow-up was 46.0 months.

All meningiomas and neuromas could be resected using a mini-open keyhole approach, but only 5.3% of the intramedullary lesions could be accessed using this technique. Of the 94 patients with intramedullary tumors, 76.6% required a laminotomy, 7.4% required a hemilaminectomy, and 10.6% required a 2-level laminectomy. Only 2 of the patients with intramedullary tumors needed stabilization for progressive cervical kyphosis during follow-up. None of the other patients developed spinal instability after undergoing surgery via the mini-open (keyhole/interlaminar) approach. There were significantly more surgery-associated complications in the large exposure group than in the patients treated with the mini-open approach (19.1% vs 9.6%, p < 0.01).

CONCLUSIONS

Intradural extramedullary and in selected cases intramedullary pathologies may safely be resected using a mini-open interlaminar approach. Avoiding laminectomy, laminotomy, and even hemilaminectomy preserves spinal stability and significantly reduces comorbidities, while still allowing for complete resection of these tumors.

Complication and Reoperation Rates Following Surgical Management of Cervical Spondylotic Myelopathy in Medicare Beneficiaries

STUDY DESIGN

Retrospective database review.

OBJECTIVE

To compare complication and reoperation rates after anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCFs), and anterior cervical corpectomy and fusion (ACCF) for cervical spondylotic myelopathy (CSM) using a large national database of Medicare beneficiaries.

SUMMARY OF BACKGROUND DATA

CSM is the most common cause of myelopathy in patients over 55 years and is considered the most common cause of spinal cord dysfunction in the world. Surgical treatment includes ACDF, PCF, or ACCF procedures.

METHODS

The PearlDiver database (2005-2012) was utilized to determine revision rates after surgical treatment of CSM by one of the aforementioned surgical treatments. Specifically, 1 to 2 level ACDF, ACCF, and PCF and 3+ level PCF cohorts were included. Each cohort was stratified by the age of 65 years. Survivorship curves were graphed and compared.

RESULTS

Of the patients younger than 65 years of age, there were 10,557 patients treated with 1 to 2 level ACDF procedures, 1319 patients with 1 to 2 level PCF procedures, 1203 patients with 1 to 2 level ACCF procedures, and 2312 patients treated with 3+ level PCF procedures. Of the elderly patients, 24,310 patients were treated with 1 to 2 level ACDFs, 4776 with 1 to 2 level PCF procedures, 3109 with 1 to 2 level ACCFs, and 7760 with 3+ level PCFs. Patients younger than 65 years of age were significantly more likely to have a reoperation procedure, than those 65 years or older when analyzing ACCF, ACDF, and 3+ level PCF procedures. ACCFs were significantly more likely than ACDFs to require reoperation. Patients treated with PCF were consistently more likely to have nondysphagia-related complications than those treated with ACDF. Rates of transfusion, dysphagia, and hematoma/seroma formation were significantly increased with ACCF compared with ACDF within the elderly population.

CONCLUSION

The elderly are significantly less likely to have a revision surgery after surgical treatment for CSM. Patients treated with ACCF are more likely to need a revision than those treated with ACDF.

LEVEL OF EVIDENCE

3.

Transforaminal Resection of Cervical Dumbbell Schwannomas in Patients with Additional Tumors

BACKGROUND

It is rare for 2 primary tumors to occur simultaneously in a patient. Management of cervical dumbbell schwannomas (CDSs) with concurrent tumors (CTs) requires a specific neurosurgical strategy. The primary objective of this study is to investigate surgical strategies for CDSs with CTs while preserving as much of the mechanically relevant bone structures as possible.

METHODS

Twelve patients with concurrent CTs and CDSs were identified from 3 medical centers. Surgical strategies for CDSs were based on accurate preoperative images and subsequent treatment considerations for CTs. All patients received surgical treatment for CDSs and CTs. Clinical features, surgical considerations for a transforaminal approach (TA), and ultimate outcome were studied retrospectively.

RESULTS

Gross total resection of CDSs was achieved with endoscopic and microscopic assistance in 9 cases, and subtotal resection was achieved in 3 cases after the head and neck surgeons exposed and removed the extraforaminal anatomy. One patient required an additional hemilaminectomy for the resection of the intraspinal segment. After wound healing, patients were transferred to the appropriate surgical department for surgery on CTs with cervical spine stabilization after a transforaminal approach.

CONCLUSIONS

In most patients, the stability of the cervical spine can be preserved with low invasive microsurgical or endoscopic transforaminal resection. CTs could be surgically treated sequentially after microscopic- and endoscopic-assisted resection of CDSs.

Role of resection and adjuvant therapy in long-term disease outcomes for low-grade pediatric intramedullary spinal cord tumors

OBJECTIVE Surgical excision is the mainstay treatment for resectable low-grade intramedullary spinal cord tumors (IMSCTs) in the pediatric age group. Chemotherapy and radiation treatments are generally reserved for progressive or recurrent disease. Given the indolent nature of low-grade tumors and the potential side effects of these approaches, their long-term treatment benefits are unclear. The aim of the study was to determine long-term disease outcomes and the therapeutic roles of surgery and adjuvant therapies in pediatric patients with low-grade IMSCTs over an extended follow-up period. METHODS Case records for all pediatric patients (< 21 years of age) with a histopathological diagnosis of low-grade IMSCT were selected over a period from January 1975 to January 2010. Outcome variables including McCormick functional grade, overall survival (OS), and progression-free survival (PFS) were analyzed with respect to demographic and treatment variables. RESULTS Case records of 37 patients with low-grade IMSCTs were identified, with a mean follow-up duration of 12.3 ± 1.4 years (range 0.5-37.2 years). Low-grade astrocytomas were the most prevalent histological subtype (n = 22, 59%). Gross-total resection (GTR) was achieved in 38% of patients (n = 14). Fusion surgery was required in 62% of patients with pre- or postoperative deformity (10 of 16). On presentation, functional improvement was observed in 87% and 46% of patients in McCormick Grades I and II, respectively, and in 100%, 100%, and 75% in Grades III, IV, and V, respectively. Kaplan-Meier PFS rates were 63% at 5 years, 57% at 10 years, and 44% at 20 years. OS rates were 92% at 5 years, 80% at 10 years, and 65% at 20 years. On multivariate analysis, shunt placement (hazard ratio [HR] 0.33, p = 0.01) correlated with disease progression. There was a trend toward improved 5-year PFS in patients who received adjuvant chemotherapy and radiation therapy (RT; 55%) compared with those who did not (36%). Patients who underwent subtotal resection (STR) were most likely to undergo adjuvant therapy (HR 7.86, p = 0.02). CONCLUSIONS This extended follow-up duration in patients with low-grade IMSCTs beyond the first decade indicates favorable long-term OS up to 65% at 20 years. GTR improved PFS and was well tolerated with sustained functional improvement in the majority of patients. Adjuvant chemotherapy and RT improved PFS in patients who underwent STR. These results emphasize the role of resection as the primary treatment approach, with adjuvant therapy reserved for patients at risk for disease progression and those with residual tumor burden.

Management of cervical spine deformity after intradural tumor resection

Management of intradural spinal tumors requires posterior decompressive techniques. Cervical spine deformity secondary to sagittal and/or coronal imbalance after a laminectomy may result in significant cervical pain and functional deterioration, as well as neurological deficits in the most severe cases. In this paper, the authors discuss the management of cervical spine deformity after intradural tumor resection, with emphasis on the surgical strategies required to reestablish acceptable cervical spine alignment and to correct postoperative deformity. In general, after an oncological evaluation, assessing the alignment, extent, and flexibility of the deformity is mandatory before surgical planning. Rigid deformities require an osteotomy and, most often, combined approaches to restore cervical alignment. Flexible deformities can often be treated with a single approach, although a circumferential approach has its advantages.

Spinal tumors in children: long-term retrospective evaluation of a series of 134 cases treated in a single unit of pediatric neurosurgery

BACKGROUND CONTEXT

Spinal tumors in childhood are rare and heterogeneous, and their treatment is very demanding. It is necessary to both manage the disease and preserve the spinal stability so that the spine can grow normally. As a consequence, results in terms of both mortality and morbidity are often suboptimal.

PURPOSE

The results of a single pediatric neurosurgery institution are reported to highlight the peculiarities and pitfalls of the management of this disease. Tumors are analyzed from the point of view of their localization, histology, and outcome in terms of mortality and morbidity, with a special focus on postoperative spinal deformity.

STUDY DESIGN

The study design was retrospective.

PATIENT SAMPLE

Between 1995 and 2011, 134 children (75 males and 59 females) were admitted for spinal tumors, accounting for 7.7% of all the patients admitted for central nervous system malignancies. The mean age was 8.5 years (14 days-26 years), and the mean follow-up was 28 months (3 months-13 years).

OUTCOME MEASURES

Clinical and radiological outcomes were evaluated to assess mortality, morbidity, and surgical outcomes. A special interest was directed toward morbidity related to spinal deformity and neurologic deficits.

METHODS

Patients were divided into four groups: intramedullary (46 patients), intradural extramedullary (25 patients), extradural (53 patients), and paravertebral tumors (10 patients). Data were obtained retrospectively from medical records and radiological archives.

RESULTS

Low-grade glioma was the most common histology (14.1%). One hundred seventeen patients were surgically treated, with a total of 138 surgical procedures. A posterior approach was chosen in 111 cases, with osteoplastic laminotomy in 80. Radiotherapy was administered to 22 patients and chemotherapy to 26. At the last follow-up, 16 patients (11.9%) had died. A good control of the tumor with clinical improvement was reported in 100 patients (74.6%). Five patients developed a spinal instability (3.7%).

CONCLUSIONS

The goals of surgery should be histology, spine and nerve root decompression, and preservation of spinal stability. In our experience, osteoplastic laminotomy was a good surgical approach to perform the resection of the tumor with a low risk of secondary spinal instability.

Predicting sagittal deformity after surgery for intramedullary tumors

OBJECT

Spinal deformity after surgery for intramedullary tumors is a potentially serious complication that may require subsequent fusion. The aim of this study was to determine whether there were risk factors that could be used to predict postoperative sagittal deformity.

METHODS

The authors conducted a retrospective study of patients harboring an intramedullary tumor who had undergone surgery at a single center between 1985 and 2011. The main outcome of interest was the difference, at the last follow-up, between post- and preoperative measures of the Cobb angle formed by the superior and inferior limits of the laminectomy (ΔCobb).

RESULTS

Sixty-three patients were eligible for inclusion in the study. The mean sagittal deformity, measured as described above, was 15.9° (range 0°-77°) at a mean follow-up of 85.4 months (range 4-240 months). Univariate analysis showed increased sagittal deformity in patients 30 years old or younger (21.9° vs 13.7°, p = 0.04), undergoing a laminectomy involving 4 or more levels (19.3° vs 12.1°, p = 0.04), and undergoing a laminectomy that included a spinal junction (20.8° vs 12.4°, p = 0.02). Multivariate analysis showed that only age (p = 0.01) and the number of spinal levels involved in the laminectomy (p = 0.014) were significant and independent predictors of postoperative sagittal deformity. The linear regression equation drawn from this model allows one to quantitatively predict sagittal deformity for any follow-up time point after surgery.

CONCLUSIONS

Authors of this study developed a statistical tool that could be used to plan surgery and follow-up as regards the risk of sagittal spinal deformity in patients undergoing surgery for intramedullary tumors.

Long-term incidence and risk factors for development of spinal deformity following resection of pediatric intramedullary spinal cord tumors

OBJECT

Spinal deformity in pediatric patients with intramedullary spinal cord tumors (IMSCTs) may be either due to neurogenic disability or due to secondary effects of spinal decompression. It is associated with functional decline and impairment in health-related quality-of-life measures. The authors sought to identify the long-term incidence of spinal deformity in individuals who had undergone surgery for IMSCTs as pediatric patients and the risk factors and overall outcomes in this population.

METHODS

Treatment records for pediatric patients (age < 21 years) who underwent surgical treatment for histology-proven primary IMSCTs between 1975 and 2010 were reviewed. All patients were evaluated in consultation with the pediatric orthopedics service. Clinical records were reviewed for baseline and follow-up imaging studies, surgical fusion treatment, and long-term skeletal and disease outcomes.

RESULTS

The authors identified 55 patients (30 males and 25 females) who were treated for pediatric IMSCTs between January 1975 and January 2010. The mean duration of follow-up (± SEM) was 11.4 ± 1.3 years (median 9.3 years, range 0.2-37.2 years). Preoperative skeletal deformity was diagnosed in 11 (20%) of the 55 patients, and new-onset postoperative deformity was noted in 9 (16%). Conservative management with observation or external bracing was sufficient in 8 (40%) of these 20 cases. Surgical fusion was necessary in 11 (55%). Posterior surgical fusion was sufficient in 6 (55%) of these 11 cases, while combined anterior and posterior fusion was undertaken in 5 (45%). Univariate and multivariate analysis of clinical and surgical treatment variables indicated that preoperative kyphoscoliosis (p = 0.0032) and laminectomy/laminoplasty at more than 4 levels (p = 0.05) were independently associated with development of spinal deformity that necessitated surgical fusion. Functional scores and 10-year disease survival outcomes were similar between the 2 groups.

CONCLUSIONS

Long-term follow-up is essential to monitor for delayed development of spinal deformity, and regular surveillance imaging is recommended for patients with underlying deformity. The authors' extended follow-up highlights the risk factors associated with development of spinal deformity in patients treated for pediatric IMSCTs. Surgical fusion allows patients who develop progressive deformity to achieve long-term functional and survival outcomes comparable to those of patients who do not develop progressive deformity.

Surgical outcomes in spinal cord ependymomas and the importance of extent of resection in children and young adults

OBJECT

Ependymomas are a common type of CNS tumor in children, although only 13% originate from the spinal cord. Aside from location and extent of resection, the factors that affect outcome are not well understood.

METHODS

The authors performed a search of an institutional neuropathology database to identify all patients with spinal cord ependymomas treated over the past 20 years. Data on patient age, sex, clinical presentation, symptom duration, tumor location, extent of resection, use of radiation therapy, surgical complications, presence of tumor recurrence, duration of follow-up, and residual symptoms were collected. Pediatric patients were defined as those 21 years of age or younger at diagnosis. The extent of resection was defined by the findings of the postoperative MR images.

RESULTS

A total of 24 pediatric patients with spinal cord ependymomas were identified with the following pathological subtypes: 14 classic (Grade II), 8 myxopapillary (Grade I), and 2 anaplastic (Grade III) ependymomas. Both anaplastic ependymomas originated in the intracranial compartment and spread to the spinal cord at recurrence. The mean follow-up duration for patients with classic and myxopapillary ependymomas was 63 and 45 months, respectively. Seven patients with classic ependymomas underwent gross-total resection (GTR), while 4 received subtotal resection (STR), 2 received STR as well as radiation therapy, and 1 received radiation therapy alone. All but 1 patient with myxopapillary ependymomas underwent GTR. Three recurrences were identified in the Grade II group at 45, 48, and 228 months. A single recurrence was identified in the Grade I group at 71 months. The mean progression-free survival (PFS) was 58 months in the Grade II group and 45 months in the Grade I group.

CONCLUSIONS

Extent of resection is an important prognostic factor in all pediatric spinal cord ependymomas, particularly Grade II ependymomas. These data suggest that achieving GTR is more difficult in the upper spinal cord, making tumor location another important factor. Although classified as Grade I lesions, myxopapillary ependymomas had similar outcomes when compared with classic (Grade II) ependymomas, particularly with respect to PFS. Long-term complications or new neurological deficits were rare. Among patients with long-term follow-up, those who underwent GTR had a recurrence rate of 20% compared with 40% among those with STR or biopsy only, suggesting that extent of resection is perhaps a more important prognostic factor than histological grade in predicting PFS, which has been suggested by other data in the literature. Given the relative paucity of these lesions, collaborative multiinstitutional studies are needed, and such efforts should also focus on molecular and genetic analysis to refine the current classification system.

Long-term surgical outcomes of cervical dumbbell neurinomas

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To evaluate our treatment strategy for cervical dumbbell neurinoma. In treating cervical dumbbell neurinoma, possible difficulties include reoperation due to recurrent tumor, denervation due to nerve root resection, and postoperative spinal deformity due to extensive bony removal.

METHODS

We reviewed 75 cases of cervical dumbbell neurinoma that were treated surgically between 1985 and 2006. Postoperative neurological deficits, effects of surgical margins on tumor recurrence, and surgical complications were investigated retrospectively.

RESULTS

Sensory and motor deficits due to resection of specific nerve roots appeared temporarily in 33 and 23 % of all cases, and persisted in 8 and 8 % at final evaluation, respectively. Total, subtotal, and partial resection was performed in 57, 13, and 5 cases, respectively. The total resection rate was low in the tumors that had large extraforaminal components. Of the subtotally resected 13 cases, only two cases of high tumor-growth rate required re-operation or showed tumor growth. Among the five partially resected cases, re-operation was necessary in two cases 13 and 15 years later because of aggravated neurological symptoms due to tumor growth. Two patients who underwent C2 laminectomy developed kyphosis, and three patients who underwent facet joint resection and curettage of vertebral body lesions developed scoliosis.

CONCLUSION

Total resection should be attempted for cervical dumbbell tumors. In cases where total resection was potentially of high risk, however, subtotal resection (within the capsule) was found to be a practical choice yielding favorable long-term outcome when the tumor growth rate (MIB-1 index) was low.

Ultrasonic BoneScalpel for Osteoplastic Laminoplasty in the Resection of Intradural Spinal Pathology: Case Series and Technical Note

BACKGROUND:

Osteoplastic laminoplasty is a well-described technique that may decrease the incidence of progressive kyphosis when used in the setting of intradural spinal cord tumor resection.

OBJECTIVE:

The BoneScalpel by Aesculap (Central Valley, Pennsylvania) is an ultrasonic osteotome that precisely cuts bone while preserving the underlying soft tissues, potentially reducing the risk of dural laceration during laminoplasty. By producing osteotomies as narrow as 0.5 mm, the device may also facilitate postoperative osteointegration.

METHODS:

A retrospective analysis was conducted of 40 patients (mean age, 38.0 years; range, 4.0-79.7 years) who underwent osteoplastic laminoplasty using the BoneScalpel for the treatment of intradural spinal pathology at the Johns Hopkins Hospital between January 2009 and December 2011. After lesion resection, titanium plates were used to reconstruct the lamina in all cases. The technical results and procedure-related complications were subsequently noted.

RESULTS:

Successful laminoplasty was carried out in all 40 patients. Intraoperatively, 1 case of incidental durotomy was noted after use of the device, which was repaired primarily without neurological or clinical sequelae. During the follow-up period (mean, 195 days; median, 144 days), there were 2 complications (1 cerebrospinal fluid leak, 1 seroma) and no cases of immediate postoperative instability.

CONCLUSION:

The BoneScalpel is a safe and technically feasible device for performing osteoplastic laminoplasty.

Postoperative spinal deformity after treatment of intracanal spine lesions

BACKGROUND CONTEXT

Surgical treatment of intracanal (both intramedullary and extramedullary) spine lesions requires posterior decompressive techniques in nearly all instances. Postoperative spinal deformities, most notably sagittal and coronal decompensation, are of significant concern for both the patient and the spinal surgeon.

PURPOSE

To review and define principles and features of spinal deformities after posterior spinal decompression for intracanal spinal lesions, and to define patients who may benefit from the concomitant spinal fusion.

METHODS

A systematic review of MEDLINE was conducted, including articles published between 1980 and 2011. Articles related to spinal deformities after posterior decompression for the treatment of intracanal spine lesions were identified.

RESULTS

Ten articles met all inclusion and exclusion criteria. All were case series with limited evidence (Level IV). Many risk factors to deformity were implied but with limited evidence. Young age was the most commonly identified risk in these articles.

CONCLUSIONS

Spinal deformity after posterior decompression is a common complication, most notably in children and young adults, after the removal of intramedullary tumors. Many risk factors have been implied to increase the postoperative development of spinal deformity, including young age, laminectomy extension, preoperative deformity, and extensive facet resection, among others. However, there is a lack of high-quality evidence to propose an algorithm for treatment or preventive measures. New studies with larger series of patients and standardized clinical outcomes are necessary to establish optimal treatment protocols.

Late occurrence of drop metastasis to the spine in a case of esthesioneuroblastoma

Esthesioneuroblastoma is an aggressive neuroectodermal tumor that originates from the olfactory mucosa and often recurs locally. Distant metastasis of esthesioneuroblastoma has been described, but there are few reports of drop metastasis to the spinal cord. Here, we report a case of multiple drop metastases to the cervical, thoracic, and lumbar regions of the spinal cord that occurred 18 years after resection and radiotherapy of the original anterior cranial fossa lesion. There was no evidence of local recurrence. The symptomatic lesion was treated with resection and adjuvant chemotherapy. The options available for treatment of this disease are summarized with a review of the few reported cases of spinal metastasis of esthesioneuroblastoma.

Complications associated with the treatment for spinal ependymomas

Spinal cord ependymomas are rare neoplasms, comprising approximately 5% of all CNS tumors and 15% of all spinal cord tumors. Although surgery was once reserved for diagnosis alone, the evolution of surgical practices has elevated resection to the treatment of choice for these lesions. While technological advances continue to improve the capacity for gross-total resections and thus decrease the risk of recurrence, ependymoma spinal surgery still contains a variety of potential complications. The presence of neurological deficits and deterioration are not uncommonly associated with spinal cord ependymoma surgery, including sensory loss, dorsal column dysfunction, dysesthetic syndrome, and bowel and bladder dysfunction, particularly in the immediate postoperative period. Surgical treatment may also lead to wound complications and CSF leaks, with increased risk when radiotherapy has been involved. Radiation therapy may also predispose patients to radiation myelopathy and ultimately result in neurological damage. Additionally, resections of spinal ependymomas have been associated with postoperative spinal instability and deformities, particularly in the pediatric population. Despite the advances in microsurgical techniques and intraoperative cord monitoring modalities, there remain a number of serious complications related to the treatment of spinal ependymoma tumors. Identification and acknowledgment of these potential problems may assist in their prevention, early detection, and increased quality of life for patients afflicted with this disease.

Minimally invasive microsurgical treatment of cervical intraspinal extramedullary tumors

Removal of intraspinal tumors by the classic posterior midline approach with laminectomy may cause damage to and instability of cervical segments. We investigated whether the less invasive hemilaminectomy or hemi-semi-laminectomy can achieve satisfactory clinical outcomes in 39 patients with intraspinal extramedullary tumors of the cervical spine. Twenty-seven patients were treated with conventional microsurgery using a posterior midline approach; and were compared to 12 patients treated with hemilaminectomy or hemi-semi-laminectomy using a posterior midline approach. Patients were retrospectively reviewed and their preoperative and postoperative clinical status was measured using the Frankel Grade. The surgical time for the 27 patients who underwent a classical laminectomy was 3±0.39 hours and blood loss was 123±34 mL. Twenty-five patients had their tumors removed entirely, and two patients had partial removal. Twenty-six patients were followed-up for between 38 months and 7 years (mean=5 years), of whom 23 improved and three remained in a stable condition. One patient with a meningioma had a tumor recurrence 3 years post-operatively and underwent further surgery. The surgical time for the hemilaminectomy or hemi-semi-laminectomy group was 2.5±0.3 hours and blood loss was 88±18 mL. All patients were followed-up for between 26 and 42 months (mean=31 months) and 11 recovered to an improved grade while one remained in a stable condition. No patient had a tumor recurrence. The hemilaminectomy or hemi-semi-laminectomy approach achieved similar clinical outcomes to the conventional posterior midline laminectomy approach and was also associated with a shorter operative time, decreased intraoperative blood loss, greater preserved ligament and bone structure and a reduced deformity rate.

Balancing spinal stability and future mobility in the cervical spine: surgical treatment of a case of osteoblastoma with secondary aneurysmal bone cyst

BACKGROUND CONTEXT

The combination of osteoblastoma and aneurysmal bone cyst (ABC) in the cervical spine is a relatively rare occurrence in the general population. The diagnosis and surgical management of osteoblastoma and ABCs have been previously described in a small number of case reports/series and orthopedic texts. Lesions of the cervical spine pose challenges to surgeons that require preoperative planning and intraoperative decisions to ensure an appropriate patient outcome. Complete resection has been shown to be the most effective method for preventing recurrence; however, balancing spinal stability, future mobility, and complete resection is especially important in active young patients.

PURPOSE

We describe a modern approach to the surgical management of osteoblastoma with secondary ABC of the cervical spine with 4-year clinical and radiographic follow-up. Included in this report is a comprehensive review of the literature related to osteoblastoma, ABCs, and surgical issues pertinent to them.

STUDY DESIGN

An independent retrospective case review combined with a review of current literature was performed.

PATIENT SAMPLE

A single patient with a combination of osteoblastoma and secondary ABC is presented.

OUTCOME MEASURES

During 4 years of follow-up, the patient has been evaluated with plain radiographs for subluxation or rotation of the cervical spine. Postoperative assessments for pain and range of motion were also collected.

METHODS

The medical, pathologic, and radiographic records of a case of osteoblastoma with secondary aneursymal bone cyst of the cervical spine were reviewed. A computer-based literature search of the PubMed database was used to compile a comprehensive review of the topic.

RESULTS

The diagnosis and surgical treatment of osteoblastoma with secondary ABC in the cervical spine are discussed in the context of a literature review. The surgical management of this lesion was dictated by the size and location of the mass as well as the impact of the surgical resection on surrounding structures in terms of spinal stability and future mobility.

CONCLUSIONS

The combination of osteoblastoma and ABC in the cervical spine is an uncommon occurrence in the general population. In the cervical spine, careful surgical planning and a case-by-case evaluation must be implemented to minimize morbidity and recurrence for every patient.

Cervical kyphosis trapezius sign: a new sign for an old pathology

OBJECTIVE

Cervical kyphosis may develop in patients with a variety of conditions. It commonly occurs following cervical spine surgery. To our knowledge, no specific physical examination finding in patients with cervical kyphosis has been previously described. It has been our observation that patients with symptomatic cervical kyphosis often have prominent, taut, and painful trapezius muscles. We coined the term cervical kyphosis trapezius sign (CKTS). This article describes the use of this sign as a clinical marker for management and outcome assessment.

METHODS

We retrospectively analyzed the files of symptomatic cervical kyphosis patients who have been treated by the senior author (E.C.B.) and have been photographed. We also quantified the reliability and accuracy of CKTS by presenting clinical photographs to health care providers.

RESULTS

Fifteen patients fulfilled the inclusion criteria. All patients had preoperative photographs of their neck that showed the CKTS. Six patients were treated conservatively and nine underwent surgical correction. Mean follow-up for surgical cases was 14.7 months. Postoperative neck photographs demonstrated a normalization of the prominent and painful trapezius muscle in each case. When examining the reliability of CKTS, we found overall interobserver reliability to be 0.671 with an intraobserver reliability of 0.678.

CONCLUSION

CKTS is a simple, objective, and potentially clinically useful indicator of cervical kyphotic deformity. Resolution of CKTS postoperatively had an associated high rate of pain relief. Therefore, the presence of CKTS in a symptomatic patient with cervical kyphosis is a potential indicator for surgical correction of the deformity.

Infantile cervical intramedullary cavernous angioma manifesting as hematomyelia. Case report

A 2-month-old infant presented with a cervical intramedullary spinal cord cavernous angioma manifesting as left hemiparesis caused by hematomyelia. Osteoplastic laminotomy of the cervical spine was carried out with subsequent microsurgical excision of the intramedullary spinal cord cavernous angioma. Magnetic resonance imaging revealed no residual tumor. At 25 months after the surgery, she presented no neurological deficit without recurrence and cervical deformity. This case of infantile intramedullary spinal cord cavernous angioma presenting with cervical hematomyelia shows osteoplastic laminotomy of the cervical spine might be helpful to prevent consequent cervical deformity in pediatric cases.

Short-term progressive spinal deformity following laminoplasty versus laminectomy for resection of intradural spinal tumors: analysis of 238 patients

OBJECTIVE

Gross total resection of intradural spinal tumors can be achieved in the majority of cases with preservation of long-term neurological function. However, postoperative progressive spinal deformity complicates outcome in a subset of patients after surgery. We set out to determine whether the use of laminoplasty (LP) vs laminectomy (LM) has reduced the incidence of subsequent spinal deformity following intradural tumor resection at our institution.

METHODS

We retrospectively reviewed the records of 238 consecutive patients undergoing resection of intradural tumor at a single institution. The incidence of subsequent progressive kyphosis or scoliosis, perioperative morbidity, and neurological outcome were compared between the LP and LM cohorts.

RESULTS

One hundred eighty patients underwent LM and 58 underwent LP. Patients were 46 +/- 19 years old with median modified McCormick score of 2. Tumors were intramedullary in 102 (43%) and extramedullary in 102 (43%). All baseline clinical, radiographic, and operative variables were similar between the LP and LM cohorts. LP was associated with a decreased mean length of hospitalization (5 vs 7 days; P = .002) and trend of decreased incisional cerebrospinal fluid leak (3% vs 9%; P = .14). Following LP vs LM, 5 (9%) vs 21 (12%) patients developed progressive deformity (P = .728) a mean of 14 months after surgery. The incidence of progressive deformity was also similar between LP vs LM in pediatric patients < 18 years of age (43% vs 36%), with preoperative scoliosis or loss of cervical/lumbar lordosis (28% vs 22%), or with intramedullary tumors (11% vs 11%).

CONCLUSION

LP for the resection of intradural spinal tumors was not associated with a decreased incidence of short-term progressive spinal deformity or improved neurological function. However, LP may be associated with a reduction in incisional cerebrospinal fluid leak. Longer-term follow-up is warranted to definitively assess the long-term effect of LP and the risk of deformity over time.

Minimally invasive resection of intramedullary ependymoma: case report

OBJECTIVE

This report illustrates the adequacy of minimally invasive exposure for the resection of an intramedullary ependymoma.

CLINICAL PRESENTATION

The patient presented with a history of upper back pain, but a lesion was found during a workup for increased back pain after a motor vehicle accident.

INTERVENTION

The intramedullary ependymoma was approached using a muscle-splitting retractor and extended hemilaminar exposure. The tumor was removed using conventional techniques.

CONCLUSION

This minimally invasive exposure is adequate for selected intramedullary lesions and may be especially useful in patients with a high risk of postlaminectomy deformity.

Upper cervical spinal cord tumors: review of 13 cases

BACKGROUND

Clinical features of upper cervical spinal cord tumors are not clear because there have been too few published reports. The purpose of this study was to review the clinical features of these tumors.

METHODS

We reviewed 13 patients who underwent surgery for an upper cervical spinal cord tumor. Data regarding age, sex, duration and type of symptoms, levels, topographical locations, surgical results, and histological features were investigated retrospectively.

RESULTS

Of the 13 tumors, 5 were at C1/2, 7 at C2/3 and 1 at C1-3. Topographically, 9 of the 13 tumors were dumbbell shaped, and all 5 at C1/2 had this shape. The initial symptom was occipital pain in three patients, numbness or pain of the extremity in nine, and clumsiness of the upper extremity in one. The average duration from initial symptom to surgery was 14.9 months. There were no major surgical complications, but there were three cases of postoperative cervical kyphosis. These three patients underwent tumorectomy with total laminectomy of C2. Tumor recurrence was seen in three patients for reasons thought to be the same as tumors at other levels, being residual meningiomas lying ventral to the cord and extraforaminal neurinomas.

CONCLUSIONS

Spinal cord tumors in the upper cervical region tend to progress as dumbbell tumors. As all the neurinomas had this shape (Eden type 2 or 3) at C1/2, this anatomy might favor progression to the extradural and extraforaminal spaces.However, it also allows total removal of the tumor via a posterior approach. To maintain postoperative cervical alignment, the surgeon should select the least invasive approach to the paraspinal muscles attached to the spinous process of C2.

Correlation of a preoperative grading scale with progressive spinal deformity following surgery for intramedullary spinal cord tumors in children

OBJECT

Postoperative progressive spinal deformity often complicates functional outcome after resection of pediatric intramedullary spinal cord tumors (IMSCTs). The authors propose a preoperative grading scale that correlates with the postoperative development of progressive spinal deformity requiring subsequent fusion.

METHODS

The data obtained in 164 patients who underwent resection of an IMSCT at a single institution were retrospectively collected and analyzed to determine the development of progressive spinal deformity requiring fusion. A grading scale (range of scores I-V) was created based on the presence or absence of 4 preoperative variables: preoperative scoliosis, involvement of the thorocolumbar junction, age<13 years, and number of surgeries for an IMSCT. The grading scale was then retrospectively applied to this series of 164 children to assess the correlation of variables with subsequent spinal deformity.

RESULTS

Nine patients presented with Grade I status, 41 patients with Grade II, 58 patients with Grade III, 44 patients with Grade IV, and 12 patients with Grade V. Overall, 44 patients (27%) developed progressive spinal deformity requiring fusion at a mean follow-up of 5 years after surgery. A higher preoperative grade was associated with an increasing need for subsequent fusion for progressive spinal deformity (Grade I [0%], Grade II [5%], Grade III [26%], Grade IV [40%], and Grade V status [75%]).

CONCLUSIONS

Application of this grading scheme to a series of resected pediatric IMSCTs has demonstrated its correlation with the incidence of postoperative progressive spinal deformity requiring fusion. The application of a standardized grading scheme will assist in the process of surgical decision making and postoperative evaluation.

Factors associated with cervical instability requiring fusion after cervical laminectomy for intradural tumor resection

Object

The indications remain unclear for fusion at the time of cervical laminectomy for intradural tumor resection. To identify patients who may benefit from initial fusion, the authors assessed clinical, radiological/imaging, and operative factors associated with subsequent symptomatic cervical instability requiring fusion after cervical laminectomy for intradural tumor resection.

Methods

The authors reviewed 10 years of data obtained in patients who underwent cervical laminectomy without fusion for intradural tumor resection and who had normal spinal stability and alignment preoperatively. The association of pre- and intraoperative variables with the subsequent need for fusion for progressive symptomatic cervical instability was assessed using logistic regression analysis, and percentages were compared using Fisher exact tests when appropriate.

Results

Thirty-two patients (mean age 41 ± 17 years) underwent cervical laminectomy without fusion for resection of an intradural tumor (18 intramedullary and 14 extramedullary). Each increasing number of laminectomies performed was associated with a 3.1-fold increase in the likelihood of subsequent vertebral instability (odds ratio 3.114, 95% confidence interval 1.207–8.034, p = 0.02). At a mean follow-up interval of 25.2 months, 33% (4 of 12) of the patients who had undergone a ≥ 3-level laminectomy required subsequent fusion compared with 5% (1 of 20) who had undergone a ≤ 2-level laminectomy (p = 0.03). Four (36%) of 11 patients initially presenting with myelopathic motor disturbance required subsequent fusion compared with 1 (5%) of 21 presenting initially with myelopathic sensory or radicular symptoms (p = 0.02). Age, the presence of a syrinx, intramedullary tumor, C-2 laminectomy, C-7 laminectomy, and laminoplasty were not associated with subsequent symptomatic instability requiring fusion.

Conclusions

In the authors' experience with intradural cervical tumor resection, patients presenting with myelopathic motor symptoms or those undergoing a ≥ 3-level cervical laminectomy had an increased likelihood of developing subsequent symptomatic instability requiring fusion. A ≥ 3-level laminectomy with myelopathic motor symptoms may herald patients most likely to benefit from cervical fusion at the time of tumor resection.