Fehlings, Michael G.

Study Design: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. Objective: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. Methods: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. Results: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. Conclusions: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation.

Introduction Vertebral artery injury is a rare but serious complication of cervical spine surgery with an overall incidence rate of 1.4% (Rampersaud, 2006). Iatrogenic injury of the vertebral artery can lead to serious complications including lateral medullary (Wallenberg) syndrome, quadriparesis, and mortality. The high rate of vertebral artery anomalies in the general population mandates assessment via advanced imaging modalities in the preoperative period (Schroeder, 2013). The rarity of this complication makes it difficult to set expectations after an injury is encountered. This study utilized a multi-center database to compile outcomes data after vertebral artery injury during a cervical spine procedure. Materials and Methods A multi-center retrospective case series was compiled involving 23 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005–2011 and who sustained a vertebral artery injury. IRBs were obtained from all institutions and data was sent to a private research organization that collected and collated all of the data. Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). Results Vertebral artery injuries were identified in a total of 14 of 16,582 total patients screened (8.4 per 10,000). The mean age of patients with vertebral artery injury was 59 years (+/− 10) with a female predominance (78.6%). Diagnoses of affected patients included 7 with myelopathy, 3 with radiculopathy, 1 with cervical instability, and 2 with metastatic disease. The mean duration of operative time for cases was 4.7 hours (+/− 1.8). Vertebral artery injury was also associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior only approach, 3 cases with posterior only approach, and 4 during circumferential approach. Average length of hospital stay for these patients was 10 days (+/− 8). Notably, 13 of the 14 (92.86%) cases reportedly resolved without residual deficits. Compared with preoperative baseline NDI, Nurick, and SF-36 physical and mental component scores for these patients, there were no observed changes after surgery ( p = 0.20 Ð 0.94). Conclusion Vertebral artery injuries are potentially catastrophic complications that can be sustained from either anterior or posterior cervical spine approaches. This adverse event is associated with an increase in hospital stay and functional disability measured on NDI score. However, the data from this study suggests that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits (13 out of 14). Preoperative imaging studies may provide insight into VA anomalies and anatomic variations and are vital to the preoperative assessment. Furthermore, although surgeons should expect increased blood loss once a vertebral artery injury is encountered, patients do not often require a blood transfusion.

Introduction Symptomatic Metastatic Epidural Spinal Cord Compression (MESCC) afflicts up to 10% of all cancer patients and is associated with shortened survival and worsened quality of life. This study aims to identify the key survival prognostic factors in MESCC patients who were surgically treated for a single symptomatic lesion. Material and Methods 142 MESCC patients were enrolled in a prospective North American multi-center study and followed postoperatively for 12 months. Using univariate analyses, Kaplan-Meier methods, and log-rank tests the prognostic value of various clinical predictors were assessed. Non-collinear predictors with p < 0.05 in univariate analyses were included in the final Cox proportional hazards model. Results The overall median survival was 7.7 months (range: 3 days – 35.6 months); breast cancer had the longest median survival (12.1 months). Ten patients (7%), whose primary cancer were lung (3), kidney (3), sarcoma (2), prostate (1), and breast (1), died within 30-days postoperatively and 88 had died at 12 months (62%). Univariate analyses yielded eight significant predictors for survival: the growth of primary tumor (Tomita Grade 1 vs Grade 2 and 3), BMI, gender, preoperative SF-36 physical component, EQ-5D, and ODI scores as well as the presence of either visceral or extraspinal bony metastasis. The multiple regression analysis revealed that the Tomita grade (Grade 1 vs Grade 2 and 3; HR: 2.81, p = 0.007), the absence of visceral metastasis (HR: 2.01; p = 0.0044), and higher score on SF-36 physical component (HR: 0.95, p < 0.0001) were independent predictors for longer survival regardless of the selection method used (backward, forward, or stepwise). Conclusion Slow growing tumor (Tomita Grade 1), absence of visceral metastasis, and lower degree of preoperative physical disability, as reflected by a higher score on the SF-36 physical component questionnaire, are good prognostic factors for survival in selected patients who underwent surgical treatment for a focal symptomatic MESCC lesion.

Introduction Although surgery is being increasingly used in patients with Metastatic Epidural Spinal Cord Compression (MESCC) as a complementary strategy to radiation and chemotherapy, the impact of surgery on quality of life (QoL) is not well established. This study aimed to prospectively evaluate survival, neurological, functional, and QoL outcomes in MESCC patients undergoing operative management. Material and Methods A total of 142 surgically treated patients with a single symptomatic MESCC lesion enrolled in a prospective North American multi-center study were followed for 12 months. Clinical data, such as Brief Pain Inventory (BPI), ASIA, SF-36, Oswestry Disability Index (ODI), and EQ-5D scores, were obtained both pre- and post-operatively. Results The median survival was 7.7 months. The 30-day and 12-month mortality rates were 9% and 62%, respectively. Six weeks post-operatively, ambulatory status ( p = 0.02) and bladder control ( p = 0.03) were significantly improved. Overall, 67.5% of ASIA B, C, or D patients gained at least 1 grade after surgery, 25% remained stable, and 7.5% deteriorated. ODI, EQ-5D, BPI scores were significantly improved at each follow-up (p ≤ 0.01). SF-36 scores were generally higher after surgery for mental and physical components, and for all domains except energy/fatigue. The incidence of wound complications was 10% and 2 patients required a second surgery (screw malposition and epidural hematoma). Conclusion Surgical intervention, as a complementary adjunct to radiation and chemotherapy, provides immediate and sustained improvement in pain, neurological, functional, and QoL outcomes with acceptable risks in patients with a focal symptomatic MESCC lesion.

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.

OBJECT A chordoma is an indolent primary spinal tumor that has devastating effects on the patient's life. These lesions are chemoresistant, resistant to conventional radiotherapy, and moderately sensitive to proton therapy; however, en bloc resection remains the preferred treatment for optimizing patient outcomes. While multiple small and largely retrospective studies have investigated the outcomes following en bloc resection of chordomas in the sacrum, there have been few large-scale studies on patients with chordomas of the mobile spine. The goal of this study was to review the outcomes of surgically treated patients with mobile spine chordomas at multiple international centers with respect to local recurrence and survival. This multiinstitutional retrospective study collected data between 1988 and 2012 about prognosis-predicting factors, including various clinical characteristics and surgical techniques for mobile spine chordoma. Tumors were classified according to the Enneking principles and analyzed in 2 treatment cohorts: Enneking-appropriate (EA) and Enneking-inappropriate (EI) cohorts. Patients were categorized as EA when the final pathological assessment of the margin matched the Enneking recommendation; otherwise, they were categorized as EI. METHODS Descriptive statistics were used to summarize the data (Student t-test, chi-square, and Fisher exact tests). Recurrence and survival data were analyzed using Kaplan-Meier survival curves, log-rank tests, and multivariate Cox proportional hazard modeling. RESULTS A total of 166 patients (55 female and 111 male patients) with mobile spine chordoma were included. The median patient follow-up was 2.6 years (range 1 day to 22.5 years). Fifty-eight (41%) patients were EA and 84 (59%) patients were EI. The type of biopsy (p < 0.001), spinal location (p = 0.018), and if the patient received adjuvant therapy (p < 0.001) were significantly different between the 2 cohorts. Overall, 58 (35%) patients developed local recurrence and 57 (34%) patients died. Median survival was 7.0 years postoperative: 8.4 years postoperative for EA patients and 6.4 years postoperative for EI patients (p = 0.023). The multivariate analysis showed that the EI cohort was significantly associated with an increased risk of local recurrence in comparison with the EA cohort (HR 7.02; 95% CI 2.96–16.6; p < 0.001), although no significant difference in survival was observed. CONCLUSIONS EA resection plays a major role in decreasing the risk for local recurrence in patients with chordoma of the mobile spine.

OBJECT In this clinically based systematic review of cervical facet fractures, the authors’ aim was to determine the optimal clinical care for patients with isolated fractures of the cervical facets through a systematic review. METHODS A systematic review of nonoperative and operative treatment methods of cervical facet fractures was performed. Reduction and stabilization treatments were compared, and analysis of postoperative outcomes was performed. MEDLINE and Scopus databases were used. This work was supported through support received from the Association for Collaborative Spine Research and AOSpine North America. RESULTS Eleven studies with 368 patients met the inclusion criteria. Forty-six patients had bilateral isolated cervical facet fractures and 322 had unilateral isolated cervical facet fractures. Closed reduction was successful in 56.4% (39 patients) and 63.8% (94 patients) of patients using a halo vest and Gardner-Wells tongs, respectively. Comparatively, open reduction was successful in 94.9% of patients (successful reduction of open to closed reduction OR 12.8 [95% CI 6.1–26.9], p < 0.0001); 183 patients underwent internal fixation, with an 87.2% success rate in maintaining anatomical alignment. When comparing the success of patients who underwent anterior versus posterior procedures, anterior approaches showed a 90.5% rate of maintenance of reduction, compared with a 75.6% rate for the posterior approach (anterior vs posterior OR 3.1 [95% CI 1.0–9.4], p = 0.05). CONCLUSIONS In comparison with nonoperative treatments, operative treatments provided a more successful outcome in terms of failure of treatment to maintain reduction for patients with cervical facet fractures. Operative treatment appears to provide superior results to the nonoperative treatments assessed.

Study Design Review of the literature. Objective Surgery and cement augmentation procedures are effective palliative treatment of symptomatic spinal metastases. Our objective is to systematically review the literature to describe the survival, prognostic factors, and clinical outcomes of surgery and cement augmentation procedures for breast cancer metastases to the spine. Methods We performed a literature review using PubMed to identify articles that reported outcomes and/or prognostic factors of the breast cancer patient population with spinal metastases treated with any surgical technique since 1990. Results The median postoperative survival for metastatic breast cancer was 21.7 months (8.2 to 36 months), the mean rate of any pain improvement was 92.9% (76 to 100%), the mean rate of neurologic improvement was 63.8% (53 to 100%), the mean rate of neurologic decline was 4.1% (0 to 8%), and the local tumor control rate was 92.6% (89 to 100%). Kyphoplasty studies reported a high rate of pain control in selected patients. Negative prognostic variables included hormonal (estrogen and progesterone) and human epidermal growth factor receptor 2 (HER2) receptor refractory tumor status, high degree of axillary lymph node involvement, and short disease-free interval (DFI). All other clinical or prognostic parameters were of low or insufficient strength. Conclusion With respect to clinical outcomes, surgery consistently yielded neurologic improvements in patients presenting with a deficit with a minimal risk of worsening; however, negative prognostic factors associated with shorter survival following surgery include estrogen receptor/progesterone receptor negativity, HER2 negativity, and a short DFI.

Study Design: Evidence-based systematic review. Objectives: To define the optimal treatment of fractures involving the C2 body, including those with concomitant injuries, based upon a systematic review of the literature. Summary of Background Data: Axis body fractures have customarily been treated nonoperatively, but there are some injuries that may require operative intervention. High-quality literature is sparse and there are few class I or class II studies to guide treatment decisions. Materials and Methods: A literature search was conducted using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials, and Scopus (EMBASE, MEDLINE, COMPENDEX). The quality of literature was rated according to a grading tool developed by the Center for Evidence-based Medicine. Operative and nonoperative treatment of axis body fractures were compared using fracture bony union as the primary outcome measure. As risk factors for nonunion were not consistently reported, cases were analyzed individually. Results: The literature search identified 62 studies, of which 10 were case reports which were excluded from the analysis. A total of 920 patients from 52 studies were included. The overall bony union rate for all axis body fractures was 91%. Although the majority of fractures were treated nonoperatively, there has been an increasing trend toward operative intervention for Benzel type III (transverse) axis body fractures. Nearly 76% of axis body fractures were classified as type III fractures, of which 88% united successfully. Nearly all Benzel type I and type II axis body fractures were successfully treated nonoperatively. The risk factors for nonunion included: a higher degree of subluxation, fracture displacement, comminution, concurrent injuries, delay in treatment, and older age. Conclusions: High rates for fracture union are reported in the literature for axis body fractures with nonoperative treatment. High-quality prospective studies are required to develop consensus as to which C2 body fractures require operative fixation.

Introduction Treatment of symptomatic spinal metastases through surgical decompression and reconstruction is known to improve quality of life in patients with cancer. However, most studies have been performed on patients with mixed tumor histopathology. We systematically review the literature for prognostic factors specific to the surgical treatment of prostate metastases to the spine to determine the indications and outcomes of the surgical treatment. Material and Methods A systemic review of the literature was conducted to answer the following questions: Q1. Describe the survival and functional outcomes of surgery or vertebral augmentation for prostate metastases to the spine; Q2. Determine whether overall tumor burden, Gleason score, preoperative functional markers, and favorable hormonal naivety for operative intervention; Q3. Establish whether clinical outcomes vary with the evolution of operative techniques. Expert consensus was obtained using a modified Delphi process. Results A total of 16 studies met the preset inclusion criteria. These studies were all retrospective series with a level of evidence of IV. Included studies consistently showed a large effect of hormone naivety on overall survival. In addition, studies consistently demonstrated an improvement in motor function and the ability to maintain/regain ambulation following surgery resulting in moderate strength of recommendation. All other parameters were of insufficient or low strength. Conclusion There is scant literature on the surgical treatment of prostate metastases to the spine, which represents an opportunity for future research. On the basis of the existing evidence, it appears that the surgical treatment of prostate metastases to the spine has consistently favorable results. While no consistent preoperative indicators favor nonoperative treatment, hormone naivety and high Karnofsky Performance Scores have positive effects on survival and clinical outcomes.