Evidence level of the placement of screws outside pedicle in thoracic and lumbar spine / Nível de evidência sobre a colocação de parafusos fora do pedículo na coluna torácica e lombar / Nivel de evidencia de la colocación de tornillos fuera del pedículo en columna torácica y lumbar

ABSTRACT International recommendations in spine surgery require reproducible, safe and effective procedures. The placement of pedicle screws is technically demanding and relies on different methods of support, which result a high rate of complications related to suboptimal screw placement, with reports ranging from 15.7% to 40% according to Hansen-Algenstaedt N and Koktekir E in separate studies. This study carried out a systematic review of existing literature to identify the level of evidence of the placement of pedicle screws outside the pedicle in thoracic and lumbar spine. For the systematic review, a search of the existing literature, based on the use of MeSH terms in PubMed-Medline, Ovid, The Cochrane Library, MedicLatina, Elsevier, and EBSCO databases. According to the literature found, most authors agree that the placement of screws outside the pedicle itself does not represent a serious complication or that requires repositioning in a second surgery even when they are found to have a violation up to 50% of the medial wall of the pedicle. However, they agree that repositioning should be immediate if it is shown with imaging studies such as MRI and CT that endangers vascular and/or neurological structures, or are associated with biomechanical alterations of the spine. Level of Evidence II; Systematic Review of studies level II.

RESUMO As recomendações internacionais em cirurgia da coluna vertebral, forçam a execução de procedimentos reprodutíveis, seguros e eficazes. A colocação de Parafusos transpediculares é tecnicamente exigente e se baseia em métodos diferentes de apoio, dando como resultado uma alta taxa de complicações relacionadas com a colocação sub-optima de parafusos, apresentando relatórios variando de 15,7% para 40%, de acordo com Hansen-Algenstaedt N e Koktekir E em estudos independentes. Este estudo é uma revisão sistemática da literatura existente, identificando o nível de evidência sobre a colocação de parafusos transpediculares fora do pedículo em coluna torácica e lombar. Para a revisão sistemática, foi conduzida uma pesquisa da literatura, baseada no uso de termos MeSH, nos bancos de dados: PubMed-Medline, Ovid, The Cochrane Library, MedicLatina, Elsevier e EBSCO. De acordo com o encontrado, a maioria dos autores concordam que a colocação dos parafusos fora pedículo em si não representem uma complicação grave e não obriga a realocação deles em um segundo tempo cirúrgico, mesmo que eles apresentam uma violação de até 50% da parede medial do pedículo. No entanto, concordam que o posicionamento deve ser imediato se pôr em perigo as estruturas vasculares ou neurológicas ou estarem associados a alterações na biomecânica vertebral. Nível de Evidência II; Revisão Sistemática do nível de estudos II

RESUMEN Las recomendaciones internacionales en cirugía de columna obligan a realizar procedimientos reproducibles, seguros y eficaces. La colocación de tornillos trans-pediculares es demandante técnicamente y se apoya en diversos métodos de asistencia, que dan como resultado un alto índice de complicaciones relacionadas con la colocación subóptima de los tornillos, con reportes que van desde el 15,7% al 40% según Hansen-Algenstaedt N y Koktekir E en estudios independientes. Este estudio realiza una revisión sistemática de la literatura existente, donde se identifica el nivel de evidencia de la colocación de tornillos transpediculares fuera del pedículo en la columna torácica y lumbar. Para la revisión sistemática se realizó una búsqueda de la bibliografía existente, basada en la utilización de términos MeSH, en la base de datos: PubMed-Medline, Ovid, The Cochrane Library, MedicLatina, Elsevier y EBSCO. De acuerdo con la literatura encontrada, la mayoría de los autores concuerdan en que la colocación de tornillos fuera de pedículo en sí misma no representa una complicación grave o que requiera recolocación en un segundo tiempo quirúrgico, aun cuando se encuentren con una violación de hasta el 50% de la pared medial del pedículo; sin embargo concuerdan en que la recolocación debe ser inmediata si se demuestra con estudios de imagen como IRM y TAC que pone en riesgo estructuras vasculares y/o neurológicas, o se asocian a alteraciones biomecánicas de la columna vertebral.Nivel de Evidencia II; Revisión sistemática de Estudios de Nivel II.

Multiple thoracolumbar partial lateral corpectomies in 17 dogs. / Multiple thorakolumbale partielle laterale Korpektomien bei 17 Hunden.

OBJECTIVE: To report feasibility and outcome of multiple thoracolumbar partial lateral corpectomies (TLPLCs) in dogs with predominantly ventral spinal cord compression caused by intervertebral disc disease (IVDD) in the light of reported decreased spinal stability following single TLPLC. Material und methods: In a retrospective study the records of dogs treated by multiple TLPLCs for ventral spinal cord compression caused by Hansen type I or type II IVDD were reviewed. Presurgical spinal cord compression and postsurgical decompression, as well as slot dimensions were determined based on computed tomography (CT)-myelography images. Neurological outcome was assessed based on repetitive examinations applying a modified Frankel Score as well as on an owner questionnaire. RESULTS: Seventeen dogs with a mean body weight of 20.3 kg (range 4.0-49.0 kg) were included. Fourteen dogs had two TLPLCs, two dogs had three TLPLCs and one dog had four TLPLCs performed. The mean slot depth was 63% of entire vertebral body width, the mean slot height was 29% of the entire vertebral body height, the mean slot length was 25% of the entire vertebral body length and the mean residual vertebral interslot length between two adjacent TLPLCs was 55% of the vertebral body length. At reevaluation 4 weeks after surgery, 6/17 dogs (35.3%) had the same modified Frankel Score as before surgery, whereas 11/17 dogs (64.7%) showed a neurological improvement. According to the owners 78.5% of dogs were walking normally within 6 months after surgery. The mean survival time of 16 dogs, where follow-up was available, was 951 days. CONCLUSION AND CLINICAL RELEVANCE: Multiple spinal cord compressions caused by IVDD can be eliminated by multiple, even consecutive, TLPLCs without the risk of a clinically significant risk of spinal instability.