Can semirigid fixation of the rostral instrumented segments prevent proximal junctional kyphosis in the case of long thoracolumbar fusions? A finite element study.

OBJECTIVE: Proximal junctional kyphosis (PJK) is a relatively common complication following long instrumented posterior spinal fusion. Although several risk factors have been identified in the literature, previous biomechanical studies suggest that one of the leading causes is the sudden change in mobility between the instrumented and noninstrumented segments. The current study aims to assess the biomechanical effect of 1 rigid and 2 semirigid fixation techniques (SFTs) on developing PJK. METHODS: Four T7-L5 finite element (FE) models were developed: 1) intact spine; 2) 5.5-mm titanium rod from T8 to L5 (titanium rod fixation [TRF]); 3) multiple rods from T8 to T9 connected with titanium rod from T9 to L5 (multiple-rod fixation [MRF]); and 4) polyetheretherketone rod from T8 to T9 connected with titanium rod from T9 to L5 (PEEK rod fixation [PRF]). A modified multidirectional hybrid test protocol was used. First, a pure bending moment of 5 Nm was applied to measure the intervertebral rotation angles. Second, the TRF technique's displacement from the first loading step was applied to the instrumented FE models to compare the pedicle screw stress values in the upper instrumented vertebra (UIV). RESULTS: In the load-controlled step, at the upper instrumented segment, the intervertebral rotation values relative to TRF increased by 46.8% and 99.2% for flexion, by 43.2% and 87.7% for extension, by 90.1% and 137% for lateral bending, and by 407.1% and 585.2% for axial rotation, in the case of MRF and PRF, respectively. In the displacement-controlled step, maximum pedicle screw stress values at the UIV level were highest in the case of TRF (37.26 MPa, 42.13 MPa, 44.4 MPa, and 44.59 MPa for flexion, extension, lateral bending, and axial rotation, respectively). Compared to TRF, in the case of MRF and PRF, the screw stress values were reduced by 17.3% and 27.7% for flexion, by 26.6% and 36.7% for extension, by 6.8% and 34.3% for lateral bending, and by 49.1% and 59.8% for axial rotation, respectively. CONCLUSIONS: FE analysis has shown that the SFTs increase the mobility at the upper instrumented segment and therefore provide a more gradual transition in motion between the instrumented and rostral noninstrumented segments of the spine. In addition, SFTs decrease the screw loads at the UIV level and hence could help reduce the risk for PJK. However, further investigations are recommended to evaluate the long-term clinical usefulness of these techniques.

Ewing Sarcoma of the Spine: Prognostic Variables for Survival and Local Control in Surgically Treated Patients.

STUDY DESIGN: Multicenter, ambispective observational study. OBJECTIVE: To quantify mortality and local recurrence after surgical treatment of spinal Ewing sarcoma (ES) and to determine whether an Enneking appropriate procedure and surgical margins (en bloc resection with wide/marginal margins) are associated with improved prognosis. SUMMARY OF BACKGROUND DATA: Treatment of primary ES of the spine is complex. Ambiguity remains regarding the role and optimal type of surgery in the treatment of spinal ES. METHODS: The AOSpine Knowledge Forum Tumor developed a multicenter database including demographics, diagnosis, treatment, mortality, and recurrence rate data for spinal ES. Patients were stratified based on surgical margins and Enneking appropriateness. Survival and recurrence were analyzed using Kaplan-Meier curves and log-rank tests. RESULTS: Fifty-eight patients diagnosed with primary spinal ES underwent surgery. Enneking appropriateness of surgery was known for 55 patients; 24 (44%) treated Enneking appropriately (EA) and 31 (56%) treated Enneking inappropriately (EI). A statistically significant difference in favor of EA-treated patients was found with regards to survival (P = 0.034). Neoadjuvant and postoperative chemotherapy was significantly associated with increased survival (P = 0.008). Local recurrence occurred in 22% (N = 5) of patients with an EA procedure versus 38% (N = 11) of patients with an EI procedure. The timing of chemotherapy treatment was significantly different between the Enneking cohorts (P < 0.001) and all EA-treated patients received chemotherapy treatment. Although, local recurrence was not significantly different between Enneking cohorts (P = 0.140), intralesional surgical margins and patients who received a previous spine tumor operation were associated with increased local recurrence (P = 0.025 and P = 0.018, respectively). CONCLUSION: Surgery should be undertaken when an en bloc resection with wide/marginal margins is feasible. An EA surgery correlates with improved survival, but the impact of other prognostic factors needs to be evaluated. En bloc resection with wide/marginal margins is associated with local control. LEVEL OF EVIDENCE: 3.

Surgical management of spinal osteoblastomas.

OBJECTIVE Osteoblastoma is a rare primary benign bone tumor with a predilection for the spinal column. Although of benign origin, osteoblastomas tend to behave more aggressively clinically than other benign tumors. Because of the low incidence of osteoblastomas, evidence-based treatment guidelines and high-quality research are lacking, which has resulted in inconsistent treatment. The goal of this study was to determine whether application of the Enneking classification in the management of spinal osteoblastomas influences local recurrence and survival time. METHODS A multicenter database of patients who underwent surgical intervention for spinal osteoblastoma was developed by the AOSpine Knowledge Forum Tumor. Patient data pertaining to demographics, diagnosis, treatment, cross-sectional survival, and local recurrence were collected. Patients in 2 cohorts, based on the Enneking classification of the tumor (Enneking appropriate [EA] and Enneking inappropriate [EI]), were analyzed. If the final pathology margin matched the Enneking-recommended surgical margin, the tumor was classified as EA; if not, it was classified as EI. RESULTS A total of 102 patients diagnosed with a spinal osteoblastoma were identified between November 1991 and June 2012. Twenty-nine patients were omitted from the analysis because of short follow-up time, incomplete survival data, or invalid staging, which left 73 patients for the final analysis. Thirteen (18%) patients suffered a local recurrence, and 6 (8%) patients died during the study period. Local recurrence was strongly associated with mortality (relative risk 9.2; p = 0.008). When adjusted for Enneking appropriateness, this result was not altered significantly. No significant differences were found between the EA and EI groups in regard to local recurrence and mortality. CONCLUSIONS In this evaluation of the largest multicenter cohort of spinal osteoblastomas, local recurrence was found to be strongly associated with mortality. Application of the Enneking classification as a treatment guide for preventing local recurrence was not validated.

En Bloc Resection Versus Intralesional Surgery in the Treatment of Giant Cell Tumor of the Spine.

STUDY DESIGN: Multicenter, ambispective observational study. OBJECTIVE: The aim of this study was to quantify local recurrence (LR) and mortality rates after surgical treatment of spinal giant cell tumor and to determine whether en bloc resection with wide/marginal margins is associated with improved prognosis compared to an intralesional procedure. SUMMARY OF BACKGROUND DATA: Giant cell tumor (GCT) of the spine is a rare primary bone tumor known for its local aggressiveness. Optimal surgical treatment remains to be determined. METHODS: The AOSpine Knowledge Forum Tumor developed a comprehensive multicenter database including demographics, presentation, diagnosis, treatment, mortality, and recurrence rate data for GCT of the spine. Patients were analyzed based on surgical margins, including Enneking appropriateness. RESULTS: Between 1991 and 2011, 82 patients underwent surgery for spinal GCT. According to the Enneking classification, 59 (74%) tumors were classified as S3-aggressive and 21 (26%) as S2-active. The surgical margins were wide/marginal in 27 (36%) patients and intralesional in 48 (64%) patients. Thirty-nine of 77 (51%) underwent Enneking appropriate (EA) treatment and 38 (49%) underwent Enneking inappropriate (EI) treatment. Eighteen (22%) patients experienced LR. LR occurred in 11 (29%) EI-treated patients and six (15%) EA-treated patients (P = 0.151). There was a significant difference between wide/marginal margins and intralesional margins for LR (P = 0.029). Seven (9%) patients died. LR is strongly associated with death (Relative Risk 8.9, P < 0.001). Six (16%) EI-treated patients and one (3%) EA-treated patients died (P = 0.056). With regards to surgical margins, all patients who died underwent intralesional resection (P = 0.096). CONCLUSION: En bloc resection with wide/marginal margins should be performed when technically feasible because it is associated with decreased LR. Intralesional resection is associated with increased LR, and mortality correlates with LR. LEVEL OF EVIDENCE: 3.

A multicenter cohort study of spinal osteoid osteomas: results of surgical treatment and analysis of local recurrence.

BACKGROUND CONTEXT: Spinal osteoid osteomas are benign primary tumors arising predominantly from the posterior column of the spine. These "osteoblastic" lesions have traditionally been treated with intralesional excision. PURPOSE: The purpose of the present study was to review the treatment and local recurrence rates for symptomatic spinal osteoid osteomas. STUDY DESIGN/SETTING: Multicenter ambispective cross-sectional observational cohort study. PATIENT SAMPLE: During the study period, a total of 84 patients (65 males, 19 females) were diagnosed with a spinal osteoid osteoma and received surgical treatment. The mean age at surgery was 21.8 ± 9.0 years (range: 6.7-52.4 years) and the mean follow-up was 2.7 years (13 days-14.5 years). OUTCOME MEASURES: Local recurrence, perioperative morbidity, and cross-sectional survival. METHODS: Using the AOSpine Knowledge Forum Tumor multicenter ambispective database, surgically treated osteoid osteoma cases were identified. Patient demographic, clinical and diagnostic, treatment, local recurrence, perioperative morbidity, and cross-sectional survival data were collected and retrieved. Descriptive statistics were summarized using mean/standard deviation or frequency/percentage. RESULTS: In our study, most of the tumors were localized in the mobile spine (81 of 84 [96%]); all patients reported pain as a symptom. According to the postoperative assessment, 10 (12%) patients received an en bloc resection with marginal or wide margins, whereas two (2%) patients received en bloc resections with intralesional margins, 69 (82%) patients were treated by piecemeal "intralesional" resection, and three (4%) patients were not assessed. A total of six patients (7%) experienced a local recurrence, all of which occurred in patients who had received an intralesional resection. CONCLUSIONS: Benign bone-forming tumors of the spine are uncommon. Most patients in our series underwent a piecemeal resection with intralesional margins. This remains safe with a low local recurrence rate. En bloc excision may provide more chance of complete excision of the nidus but is not mandatory. The importance of complete excision of the nidus cannot be overemphasized.

Management of Locally Recurrent Chordoma of the Mobile Spine and Sacrum: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine evidence-based guidelines for the management of locally recurrent spinal chordoma. SUMMARY OF BACKGROUND DATA: Chordoma of the spine is a low-grade malignant tumor with a strong propensity for local recurrence. Salvage therapy is challenging due to its relentless nature and refractoriness to adjuvant therapies. There are currently no guidelines regarding the best management of recurrent chordoma. METHODS: We combined the results of a systematic review with expert opinion to address the following research questions: (1) For locally recurrent chordoma of the spine without systemic disease, if surgery is planned, should en bloc resection be attempted if technically feasible with acceptable morbidity? (2) For locally recurrent chordoma without systemic disease, in which wide en bloc excision is not possible, what is the treatment of choice? (2) Should adjuvant or neoadjuvant radiation therapy be used in the treatment of locally recurrent chordoma? RESULTS: A total of nine surgical and seven radiation therapy articles met study criteria. Evidence quality was low or very low. Recurrent disease is associated with predominantly poor outcome, regardless of treatment modality. As for primary chordoma, resection with wide margins appears to confer an advantage with respect to local control, although this effect is attenuated in the setting of relapse. Postoperative radiation therapy likely reduces the rate of further relapse. CONCLUSION: (1) For locally recurrent chordoma of the spine without systemic disease, when surgery is planned, wide en bloc resection should be performed if technically feasible with acceptable morbidity. Strong recommendation, Low Quality of Evidence. (2) For locally recurrent chordoma without systemic disease, in which wide en bloc excision is not possible, partial resection is the treatment of choice. Weak recommendation, Very Low Quality of Evidence. (3) For the treatment of locally recurrent chordoma, high-dose conformal radiation therapy should be administered postoperatively to reduce the risk of further recurrence, and may be considered as a primary therapy. Strong recommendation, Very Low Quality of Evidence. LEVEL OF EVIDENCE: 2.

A Systematic Review With Consensus Expert Opinion of Best Reconstructive Techniques After Osseous En Bloc Spinal Column Tumor Resection.

STUDY DESIGN: Systematic literature review and consensus expert opinion. OBJECTIVE: To provide recommendations on reconstructive constructs for large tumor resections of the spinal column. Four questions were studied: (1) What are the best reconstructive options for single versus multilevel resections? (2) Should short segment fixation be considered in primary tumor reconstruction? (3) How should reconstructive techniques differ at various regions of the spine? (4) Does planned postoperative radiation change the fusion strategy? SUMMARY OF BACKGROUND DATA: Primary spinal tumors requiring en bloc resection are rare. Most studies focus on disease-free survival and local recurrence rates. Few studies focus on reconstructive options and outcomes with respect to fusion rates and need for revision. METHODS: A literature search was performed from January 1990 to December 2013. Data were combined and construct survivorship summarized. A survey was administered to international spine tumor surgeons, evaluating reconstructive preferences. RESULTS: The search yielded 381 articles, 12 included in the final analysis. Revision rates for anterior reconstruction were similar for autogenous strut grafts (10%), cages (7.7%), and allograft strut grafts (8.3%). There were two reports of revision from short to long segment constructs and three reports of broken pedicle screws, one requiring revision. Expert survey results revealed that most surgeons preferred cages packed with morcelized allograft and autograft (75%) for anterior reconstruction of single-level vertebrectomies, and strut bone grafting at the cervicothoracic junction (65%) and when more than one vertebrae was resected in the mid-thoracic spine (75%). Surgeons may alter their fusion technique if postoperative radiation is planned. CONCLUSION: Posterior reconstruction with at least two vertebral levels above and below is recommended. Cages should be used for single-level defects and structural bone graft alone, or in combination with a cage, should be used when spanning a defect greater than two vertebral bodies. Planned postoperative radiation may affect fusion strategy. LEVEL OF EVIDENCE: N/A.

Soft Tissue and Bone Defect Management in Total Sacrectomy for Primary Sacral Tumors: A Systematic Review With Expert Recommendations.

STUDY DESIGN: Systematic review and expert consensus. OBJECTIVE: To address the following two questions: (A) Is there a difference in outcomes after spino-pelvic reconstruction of total sacrectomy defects compared with no reconstruction? (B) What constitutes best surgical technique for soft tissue and bony reconstruction after total sacrectomy? SUMMARY OF BACKGROUND DATA: The management of the soft tissue and bony defect after total sacrectomy for primary sacral tumors remains a challenge due to the complex anatomical relationships and biomechanical requirements. The scarcity of evidence-based literature in this specialized field makes it difficult for the treating surgeon to make an informed choice. METHODS: A systematic literature review was performed (1950-2015), followed by a meeting of an international expert panel. Medline, Embase, and CINAHL databases and Cochrane Libraries were searched. Using the GRADE guidelines, the panel of experts formulated recommendations based on the available evidence. RESULTS: Three hundred fifty-three studies were identified. Of these, 17 studies were included and were case series. Seven were evaluated as high quality of evidence and nine were of low quality. There were a total of 116 participants. Three studies included patients (n = 24) with no spino-pelvic reconstruction. One study included patients (n = 3) with vascularized bone reconstruction. Twelve studies included patients (n = 80) with no soft tissue reconstruction, three studies described patients with a local flap (n = 20), and four studies with patients having regional flap reconstruction (n = 16). Patients with or without spino-pelvic reconstruction had similar outcomes with regards to walking; however, most patients in the nonreconstructed group had some ilio-lumbar ligamentous stability preserved. The wound dehiscence and return to theater rates were higher in patients with no soft tissue reconstruction. CONCLUSION: We recommend spino-pelvic reconstruction be undertaken with soft tissue reconstruction after total sacrectomy. LEVEL OF EVIDENCE: N/A.

Safety and Local Control of Radiation Therapy for Chordoma of the Spine and Sacrum: A Systematic Review.

STUDY DESIGN: Systematic literature review. OBJECTIVE: To assess the toxicity, common radiation doses, and local control (LC) rates of radiation therapy for chordoma of the spine and sacrum and identify the difference in LC and toxicity between adjuvant, salvage, and primary therapy using radiation. SUMMARY OF BACKGROUND DATA: Chordoma of the spine is typically a low-grade malignant tumor thought to be relatively radioresistant with a high rate of local recurrence and the potential for metastases. Improved results of modern radiation therapy in the treatment of chordoma support exploration of its role in the management of primary/de novo chordoma or recurrent chordoma. METHODS: We conducted a systematic literature review using PubMed and Embase databases to assess information available regarding the toxicity, LC rates, and overall survival (OS) rates for adjuvant, salvage, and primary radiation therapy for spinal and sacral chordoma. RESULTS: A total of 40 articles were reviewed. Evidence quality was low or very low. The highest rates of LC and OS were with early adjuvant RT for primary/de novo disease. Salvage RT for recurrent disease has very small cohorts and thus strong conclusions were not able be made. CONCLUSION: The use of pre- and/or post-operative photon image-guided radiotherapy (IGRT), proton or carbon ion therapy should be considered for patients undergoing surgery for the treatment of primary and recurrent chordomas in the mobile spine and sacrum, since these RT modalities may improve local control. Preoperative evaluation by the surgeon and radiation oncologist should be used to formulate a cohesive treatment plan.The use of photon IGRT or carbon ion therapy as the primary treatment of chordoma, when currently in its developmental stage, shows promise and requires clear delineation of toxicity profile and long-term local control. LEVEL OF EVIDENCE: 2.

Osteosarcoma of the spine: prognostic variables for local recurrence and overall survival, a multicenter ambispective study.

OBJECTIVE Primary spinal osteosarcomas are rare and aggressive neoplasms. Poor outcomes can occur, as obtaining marginal margins is technically demanding; further Enneking-appropriate en bloc resection can have significant morbidity. The goal of this study is to identify prognostic variables for local recurrence and mortality in surgically treated patients diagnosed with a primary osteosarcoma of the spine. METHODS A multicenter ambispective database of surgically treated patients with primary spine osteosarcomas was developed by AOSpine Knowledge Forum Tumor. Patient demographic, diagnosis, treatment, perioperative morbidity, local recurrence, and cross-sectional survival data were collected. Tumors were classified in 2 cohorts: Enneking appropriate (EA) and Enneking inappropriate (EI), as defined by pathology margin matching Enneking-recommended surgical margins. Prognostic variables were analyzed in reference to local recurrence and survival. RESULTS Between 1987 and 2012, 58 patients (32 female patients) underwent surgical treatment for primary spinal osteosarcoma. Patients were followed for a mean period of 3.5 ± 3.5 years (range 0.5 days to 14.3 years). The median survival for the entire cohort was 6.7 years postoperative. Twenty-four (41%) patients died, and 17 (30%) patients suffered a local recurrence, 10 (59%) of whom died. Twenty-nine (53%) patients underwent EA resection while 26 (47%) patients underwent EI resection with a postoperative median survival of 6.8 and 3.7 years, respectively (p = 0.048). EI patients had a higher rate of local recurrence than EA patients (p = 0.001). Patient age, previous surgery, biopsy type, tumor size, spine level, and chemotherapy timing did not significantly influence recurrence and survival. CONCLUSIONS Osteosarcoma of the spine presents a significant challenge, and most patients die in spite of aggressive surgery. There is a significant decrease in recurrence and an increase in survival with en bloc resection (EA) when compared with intralesional resection (EI). The effect of adjuvant and neoadjuvant chemotherapeutics, as well as method of biopsy, requires further exploration.

Risk Factors for Recurrence of Surgically Treated Conventional Spinal Schwannomas: Analysis of 169 Patients From a Multicenter International Database.

STUDY DESIGN: A retrospective analysis of 169 adult patients operated for a conventional spinal schwannoma from the AOSpine Multicenter Primary Spinal Tumors Database. OBJECTIVE: The aim of this study is to identify risk factors for local recurrence of conventional spinal schwannoma in patients who had surgery. SUMMARY OF BACKGROUND DATA: Schwannomas account for up to 30% of all adult spinal tumors. Total resection is the gold standard for patients with sensory or motor deficits. Local recurrence is reported to be approximately 5% and usually occurs several years after surgery. METHODS: Rates and time of local recurrence of spinal schwannoma were quantified. Predictive value of various clinical factors was assessed, including age, gender, tumor size, affected spinal segment, and type of surgery. Descriptive statistics and univariate regression analyses were performed. RESULTS: Nine (5.32%) out the 169 patients in this study experienced local recurrence approximately 1.7 years postoperatively. Univariate analyses revealed that recurrence tended to occur more often in younger patients (39.33 ±â€Š14.58 versus 47.01 ±â€Š15.29 years) and in the lumbar segment (55.56%), although this did not reach significance [hazard ratio (HR) 0.96, P = 0.127; and P = 0.195, respectively]. Recurrence also arose in the cervical and sacral spine (22.22%, respectively) but not in the thoracic area. Tumors were significantly larger in patients with recurrence (6.97 ±â€Š4.66  cm versus 3.81 ±â€Š3.34  cm), with extent in the cranial caudal direction posing the greatest hazard (HR = 1.321, P = 0.002). The location of the tumor, whether epidural, intradural, or both (P = 0.246), was not significantly related to recurrence. Regarding surgical technique, over 4 times as many patients who underwent intralesional resection experienced a recurrence proportionally to patients who underwent en bloc resection (HR = 4.178, P = 0.033). CONCLUSION: The pre-operative size of the conventional spinal schwannoma and intralesional resection are the main risk factors for local postoperative recurrence. LEVEL OF EVIDENCE: 3.

Systematic Review of En Bloc Resection in the Management of Ewing's Sarcoma of the Mobile Spine with Respect to Local Control and Disease-Free Survival.

There is no consensus on the optimal method of local control in Ewing's sarcoma (ES) of the mobile spine. Recent reports have suggested that en bloc resection may improve local control and survival. The authors therefore performed a systematic review to answer the following questions: (1) What is the outcome of en bloc resection for ES of the mobile spine with respect to local control and disease-free survival (DFS)? (2) How should residual ES of the mobile spine be treated?Inclusion criteria were articles published between the years 1960 and 2014 in English that contained more than five patients. This yielded 204 articles, from which 4 were selected for detailed analysis. The literature was graded for quality, summarized, and presented to a group of spinal oncology experts with consensus recommendations made.All 4 studies were retrospective case series graded as very low quality evidence. Local control strategies included radiotherapy (RT) alone, surgery and RT, or surgery alone. There was no standardized outcome reported across studies with respect to the type of surgical procedure, margins, and outcomes of interest such as local recurrence (LR) and DFS. When the en bloc procedures were pooled together, 2 of the 21 patients with available LR data developed LR (9.5%), and 5 of the 7 patients with available DFS data were disease free at a mean of 76 months. The remaining 2 died at 10 and 29 months, respectively. No studies were identified detailing the treatment of residual ES of the mobile spine.There is no consensus on the optimal method of local control for spinal ES or the treatment of residual disease. A weak recommendation supports that when the en bloc resection is technically possible, in combination with RT, this appears to provide superior local control than RT alone, or incomplete excision and RT. The effect on survival is indeterminate.

Reliability of the spinal instability neoplastic scale among radiologists: an assessment of instability secondary to spinal metastases.

OBJECTIVE: The spinal instability neoplastic scale (SINS) is a new classification system for tumor-related spinal instability. The SINS may prove to be a valuable tool for radiologists to communicate with oncologists and surgeons in a standardized evidence-based manner. The objective of this study was to determine the inter- and intraobserver reliability and validity of the SINS among radiologists. MATERIALS AND METHODS: Thirty-seven radiologists from 10 international sites used the SINS to categorize the degree of spinal instability in 30 patients with spinal tumors. To assess validity, we compared the SINS scores assigned by the radiologists with the SINS scores of 11 spine oncology surgeons (reference standard). Each total SINS score (range, 0-18 points) was converted into one of the following three clinical categories: 0-6 points, stable; 7-12 points, potentially unstable; and 13-18 points, unstable. In addition, each total SINS score was converted into a binary scale: 0-6 points was defined as stable, and 7-18 points was considered a current or possible instability for which surgical consultation is recommended. RESULTS: Radiologists using the SINS binary scale showed excellent (κ = 0.88) validity, substantial (κ = 0.76) interobserver agreement, and excellent (κ = 0.82) intraobserver reproducibility. Radiologists rated all unstable cases and 621 of 629 (98.7%) potentially unstable cases with a SINS score of 7 or more points, thus appropriately initiating a referral for surgical assessment. CONCLUSION: SINS is a reliable tool for radiologists rating tumor-related spinal instability. It accurately discriminates between stable and potentially unstable or unstable lesions and, therefore, can guide the need for surgical consultation.

Aneurysmal bone cysts of the spine: treatment options and considerations.

Aneurysmal bone cysts (ABCs) are benign bone lesions with annual incidences ranging from 1.4 to 3.2 cases per million people. Approximately, 10-30% of ABCs are found in the spine. Such lesions are traditionally treated with curettage or other intralesional techniques. Because ABCs can be locally aggressive, intralesional resection can be incomplete and result in recurrence. This has led to increased use of novel techniques, including selective arterial embolization (SAE). This study aims to: (1) compare outcomes based on extent of surgical resection, and (2) compare the efficacy of SAE versus surgical resection. Clinical data pertaining to 71 cases of spinal ABCs were ambispectively collected from nine institutions in Europe, North America, and Australia. Twenty-two spinal ABCs were treated with surgery, 32 received preoperative embolization and surgery, and 17 were treated with SAE. Most tumors were classified as Enneking stage 2 (n = 29, 41%) and stage 3 (n = 29, 41%). Local recurrence and survival were investigated and a significant difference was not observed between treatment groups. However, all three local recurrences occurred following surgical resection. Surgical resection was further categorized based on Enneking appropriateness. Recurrences only occurred following intralesional Enneking inappropriate (EI) resections (P = 0.10), a classification that characterized 47% of all surgical resections. Furthermore, 56% of intralesional resections were EI, compared to only 10% of en bloc resections (P = 0.01). Although SAE treatment did not result in any local recurrences, 35% involved more than five embolization procedures. Spinal ABCs can be effectively treated with intralesional resection, en bloc resection, or SAE. Preoperative embolization should be considered before intralesional resection to limit intraoperative bleeding. Treatment plans must be guided by lesion characteristics and clinical presentation.

Timing of stereotactic radiosurgery and surgery and wound healing in patients with spinal tumors: a systematic review and expert opinions.

BACKGROUND AND PURPOSE: Stereotactic radiosurgery (SRS) and surgery may be used in combination to manage cord compression due to spinal tumors. Procedure sequence and interval affect wound healing. We aimed to review the evidence on effects of timing and sequence of surgery and SRS on wound healing and bone fusion in patients with spine tumors. MATERIALS AND METHODS: We performed a comprehensive literature search (Medline, Embase, Google Scholar, Cochrane Database of Systematic Reviews) to identify relevant studies published in 2000-2011. Additional reports were identified in reference lists from relevant papers. Case reports and series discussing patients aged ≧18 with primary or metastatic tumors to the spine who underwent surgical excision with/without instrumentation and SRS before or after surgery were included. The apparent relationship of procedure sequence and interval on wound healing and bone fusion was assessed. RESULTS: Evidence on outcomes following treatment with SRS and surgery was provided in 31 studies; neither wound healing nor bone fusion were endpoints in any study. Wound healing complications were discussed in six studies (20%) including 88 patients treated with both modalities. Animal studies and limited evidence in humans suggest that at least 1 week is indicated between SRS and surgery or surgery and SRS. CONCLUSIONS: Evidence to guide decisions regarding the sequence and timing of surgery and SRS with respect to wound healing is limited. Consistent reporting of wound healing complications will improve ability to develop guidelines for optimal treatment of spinal tumors.

Does insulin-like growth factor 1 receptor (IGF-1R) targeting provide new treatment options for chordomas? A retrospective clinical and immunohistochemical study.

AIMS: The overall prognosis of chordoma is poor, and current treatment options are limited. The insulin-like growth factor 1 receptor (IGF-1R) pathway is important for cell signalling, and attractive for selective inhibition. We investigated the expression of IGF-1R and its ligands, IGF-1 and IGF-2, in a series of 50 chordomas, in order to assess whether IGF-1R-signalling could be a potential target for specific inhibition in chordomas. METHODS AND RESULTS: Fifty chordomas (34 primary tumours, 16 recurrences) from 44 patients were evaluated immunohistochemically for the expression of IGF-1R, IGF-1 and IGF-2. Thirty-eight chordomas (76%) expressed IGF-1R, 46 (92%) expressed IGF-1 and 25 (50%) expressed IGF-2. Semi-quantitative analyses revealed a moderate to strong staining intensity in ≥ 50% of tumour cells for IGF-1R, IGF-1 and IGF-2 in 18 (36%), 32 (64%) and eight (16%) chordomas, respectively. Tumour volume correlated significantly with IGF-1R-staining intensity in primary chordomas (P = 0.042). CONCLUSIONS: IGF-1R and IGF-1 are expressed in the majority of chordomas. IGF-1 expression is much stronger than IGF-2 expression. Patients whose chordomas show a moderate to strong staining intensity in ≥ 50% of tumour cells for IGF-1R (36%) might benefit most from IGF-1R targeting, particularly if they suffer from large and surgically non-resectable chordomas.

Spinal instability neoplastic score: an analysis of reliability and validity from the spine oncology study group.

PURPOSE: Standardized indications for treatment of tumor-related spinal instability are hampered by the lack of a valid and reliable classification system. The objective of this study was to determine the interobserver reliability, intraobserver reliability, and predictive validity of the Spinal Instability Neoplastic Score (SINS). METHODS: Clinical and radiographic data from 30 patients with spinal tumors were classified as stable, potentially unstable, and unstable by members of the Spine Oncology Study Group. The median category for each patient case (consensus opinion) was used as the gold standard for predictive validity testing. On two occasions at least 6 weeks apart, each rater also scored each patient using SINS. Each total score was converted into a three-category data field, with 0 to 6 as stable, 7 to 12 as potentially unstable, and 13 to 18 as unstable. RESULTS: The κ statistics for interobserver reliability were 0.790, 0.841, 0.244, 0.456, 0.462, and 0.492 for the fields of location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement, respectively. The κ statistics for intraobserver reliability were 0.806, 0.859, 0.528, 0.614, 0.590, and 0.662 for the same respective fields. Intraclass correlation coefficients for inter- and intraobserver reliability of total SINS score were 0.846 (95% CI, 0.773 to 0.911) and 0.886 (95% CI, 0.868 to 0.902), respectively. The κ statistic for predictive validity was 0.712 (95% CI, 0.676 to 0.766). CONCLUSION: SINS demonstrated near-perfect inter- and intraobserver reliability in determining three clinically relevant categories of stability. The sensitivity and specificity of SINS for potentially unstable or unstable lesions were 95.7% and 79.5%, respectively.

A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group.

STUDY DESIGN: Systematic review and modified Delphi technique. OBJECTIVE: To use an evidence-based medicine process using the best available literature and expert opinion consensus to develop a comprehensive classification system to diagnose neoplastic spinal instability. SUMMARY OF BACKGROUND DATA: Spinal instability is poorly defined in the literature and presently there is a lack of guidelines available to aid in defining the degree of spinal instability in the setting of neoplastic spinal disease. The concept of spinal instability remains important in the clinical decision-making process for patients with spine tumors. METHODS: We have integrated the evidence provided by systematic reviews through a modified Delphi technique to generate a consensus of best evidence and expert opinion to develop a classification system to define neoplastic spinal instability. RESULTS: A comprehensive classification system based on patient symptoms and radiographic criteria of the spine was developed to aid in predicting spine stability of neoplastic lesions. The classification system includes global spinal location of the tumor, type and presence of pain, bone lesion quality, spinal alignment, extent of vertebral body collapse, and posterolateral spinal element involvement. Qualitative scores were assigned based on relative importance of particular factors gleaned from the literature and refined by expert consensus. CONCLUSION: The Spine Instability Neoplastic Score is a comprehensive classification system with content validity that can guide clinicians in identifying when patients with neoplastic disease of the spine may benefit from surgical consultation. It can also aid surgeons in assessing the key components of spinal instability due to neoplasia and may become a prognostic tool for surgical decision-making when put in context with other key elements such as neurologic symptoms, extent of disease, prognosis, patient health factors, oncologic subtype, and radiosensitivity of the tumor.