3.

Study Design Retrospective analysis of 169 adult patients operated for a conventional spinal schwannoma from the AOSpine Multicenter Primary Spinal Tumors Database. Objective 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 post-operatively. Univariate analyses revealed that recurrence tended to occur more often in younger patients (39.33 ± 14.58 years versus 47.01 ± 15.29 years) and in the lumbar segment (55.56%), although this did not reach significance (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 ± 4.66 cm versus 3.81 ± 3.34 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 four 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). Conclusions The pre-operative size of the conventional spinal schwannoma and intralesional resection are the main risk factors for local post-operative recurrence.

MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC, MCC and SCR. The Lhermitte phenomenon presented more commonly in patients with a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.

Study Design Prospective study. Objective To evaluate the prevalence of Klippel-Feil syndrome (KFS) in a prospective data set of patients undergoing surgical treatment for cervical spondylotic myelopathy (CSM) and to evaluate if magnetic resonance imaging (MRI) features in patients with KFS are more pronounced than those of non-KFS patients with CSM. Methods A retrospective analysis of baseline MRI data from the AOSpine prospective and multicenter CSM-North American study was conducted. All the patients presented with at least one clinical sign of myelopathy and underwent decompression surgery. The MRIs and radiographs were reviewed by three investigators. The clinical and imaging findings were compared with patients without KFS but with CSM. Results Imaging analysis discovered 5 of 131 patients with CSM (∼3.82%) had single-level congenital fusion of the cervical spine. The site of fusion differed for all the patients. One patient underwent posterior surgery and four patients received anterior surgery. Postoperative follow-up was available for four of the five patients with KFS and indicated stable or improved functional status. All five patients demonstrated pathologic changes of adjacent segments and hyperintensity signal changes in the spinal cord on T2-weighted MRI. Multiple MRI features, most notably maximum canal compromise (p = 0.05) and T2 signal hyperintensity area (p = 0.05), were worse in patients with CSM and KFS. Conclusions The high prevalence of KFS in our surgical series of patients with CSM may serve as an indication that these patients are prone to increased biomechanical use of segments adjacent to fused vertebra. This supposition is supported by a tendency of patients with KFS to present with more extensive MRI evidence of degeneration than non-KFS patients with CSM.

No abstract

3.

A subligamentous disc herniation and patient's age inferior to 35 years at the time of the first surgery are risk factors for requiring surgical treatment of a first RLDH among workers' compensation patients.

Study Design: Diagnostic study, level of evidence III. Objective: Pyogenic spondylodiscitis can cause deformity, neurological compromise, disability, and death. Recently, a new classification of spondylodiscitis based on magnetic resonance imaging was published. The objective of this study is to perform an independent reliability analysis of this new classification. Methods: We selected 35 cases from our database of different spine centers in Latin America and from the literature; 8 observers evaluated the classification and graded the scenarios according to the methodological grading of the classification developed by Pola et al. Cases were sent to the observers in a random sequence after 3 weeks to assess intraobserver reliability. The interobserver and intraobserver reliabilities were performed with Fleiss and Cohen statistics, respectively. Results: The overall Fleiss κ value for interobserver agreement was substantial, with 0.67 (95% CI = 0.43-0.91) in the first reading and 0.67 (95% CI = 0.45-0.89) in second reading for the main types of classification. The Cohen κ value for intraobserver agreement was also substantial, with 0.68 (95% CI = 0.45-0.92). The interobserver agreement analysis for the subtypes of this classification was overall substantial, with 0.60 (95% CI = 0.37-0.83) in the first reading and 0.61 (95% CI = 0.41-0.81) in the second reading. The overall intraobserver agreement for subtypes of the classification was also substantial, with 0.63 (95% CI = 0.34-0.93). Conclusion: The new classification developed by Pola et al showed substantial interobserver and intraobserver agreements. More studies are required to validate the usefulness of this classification especially in clinical practice.