Clinical Outcome and Histological Findings After Induced Leakage of PMMA Loaded With Methotrexate and Cisplatin During Vertebroplasty: Experimental Model in Pigs.

STUDY DESIGN: Animal experimental model. OBJECTIVE: To study the clinical behavior and histological changes in the spinal cord, nerve roots and perivertebral muscles of the spine after induced leakage of polymethylmethacrylate (PMMA) loaded with antiblastic drugs during vertebroplasty in an animal model of pigs. METHODS: We performed vertebroplasty on 25 pigs. The animals were divided into 3 groups: vertebroplasty with PMMA alone (control group), vertebroplasty with PMMA loaded with methotrexate (MTX) and vertebroplasty with PMMA loaded with cisplatin (CYS). At 2 vertebral levels, epidural and prevertebral, massive cement leaks were induced. Animals were evaluated daily. Two weeks later, the pigs were sacrificed, and the tissues that came in contact with the cement were analyzed. RESULTS: The clinical results for each of the groups were reported. The control group had no clinical alterations. In the MTX group, 2 pigs died before 1 week due to pneumonitis. In the CYS group, 4 animals had motor impairment, and 3 of the 4 had paraplegia. The histological results were as follows: the control and MTX groups showed synovial metaplasia, inflammatory reaction, crystal deposits, and giant cell reaction in the dura mater and muscle and all the animals in the CYS group had spinal cord and muscular necrosis. CONCLUSIONS: Massive cement leak after vertebroplasty with PMMA loaded with cisplatin is extremely toxic to the spinal cord and muscles around the spine. Therefore, its use cannot be recommended for the treatment of vertebral metastases. Using PMMA loaded with methotrexate seems to be a safe procedure, but further research is needed.

Preoperative and Postoperative Sagittal Alignment and Compensatory Mechanisms in Patients With Posttraumatic Thoracolumbar Deformities Who Undergo Corrective Surgeries.

BACKGROUND: Secondary posttraumatic spinal kyphosis is a fixed deformity that has an asymptomatic presentation in most patients, but in some, persistent pain and disability can develop refractory to conservative treatment, which may result in the need for corrective surgery. Our aim was to analyze the modification of sagittal alignment and the variation in compensation mechanisms of spinal-pelvic segments before and after surgical correction in a group of patients with symptomatic posttraumatic kyphosis. METHODS: A retrospective cohort study of 16 consecutive patients from the beginning of 2007 until the beginning of 2017 who underwent surgery due to thoracolumbar sagittal deformities was performed. Regional kyphosis (RK), thoracic kyphosis (TK), lumbar lordosis (LL), lower lumbar lordosis (LLL), lumbar lordosis under the deformity (LLUD), pelvic incidence (PI), pelvic tilt (PT), sagittal vertical axis (SVA), and PI-LL were measured in preoperative and postoperative lateral full spine x rays. Statistical analysis was performed with the nonparametric Wilcoxon test to compare preoperative and postoperative radiologic variables. RESULTS: Sixteen patients were included with a median age of 47.5 years (32-62 years), the median time elapsed from the accident until corrective surgery was 7 months (2-33 months), the median follow-up time was 16.5 months (6-80 months), and the most used corrective strategy was pedicle subtraction osteotomy (11/16 patients). Statistically and radiologically significant improvements were observed in RK (33.5° versus 12°, P < .001) and LLUD (68.5° versus 61°, P = .017), with a noticeable decrease in PI-LL (15° versus 9.5°, P = .233). There were no statistically significant results regarding TK, LL, LLL, PI, PT, or SVA. CONCLUSIONS: Osteotomies are an effective tool to correct angular deformities at a local level after spine trauma. Posttraumatic kyphosis results in the compensation of sagittal imbalance through modification of segmental alignment of the mobile spine under the deformity. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: This work shows the compensation mechanisms after post-traumatic kyphosis in patients with previously healthy spines.

Twelve years of scientific production on Medline by Latin American spine surgeons.

BACKGROUND: Despite the small contribution of LA in the Science Citation Index (SCI), a growing contribution by LA research to international literature has been observed in recent years. STUDY DESIGN: Systematic review. PURPOSE: To evaluate the scientific contribution of Latin American (LA) Spine Surgeons in the last decade. METHODS: A literature search of publications by LA spinal surgeons on topics concerning the spine or spinal cord was performed using an online database; Pubmed.gov. The results were limited to articles published from January 2000 to December 2011. The quality of the publication was evaluated with the journal impact factor (IF), Oxford classification and number of citations. RESULTS: This study comprised 320 articles published in the Medline database by LA spine surgeons from 2000 to 2011. In recent years, there has been an increase in the number of publications by LA spine surgeons. It was observed that 38.4% of LA papers were published in LA journals. 46.6% of the articles were published in journals with an IF lower than 1, and there was no statistically significant difference in the number of articles published in journals with a higher IF during the period. Linear-by-linear association analysis demonstrated an improvement in the level of evidence provided by LA articles published in recent years. CONCLUSIONS: This study showed a growth in the number of publications in last 12 years by LA spinal surgeons. It is necessary to discuss a way to increase quantity and quality of scientific publications, mainly through a better education in research.