The Influence of Schmorl Nodes in Spinal Sagittal Balance in Young Adults.

Objectives The present study aims to characterize the spinal balance (SB) in young adults with Schmorl nodes (SN). Methods A cross-sectional study was conducted on a sample of 47 young adults. Lumbar magnetic resonance imaging (MRI) was used to divide the patients into an SN group and a control group. Standing full spine radiographs were used to compare the spinopelvic SB parameters between groups: sagittal vertical axis, thoracic kyphosis, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Results The LL and SS values were significantly lower in patients with SN when compared with the control group (54.5° versus 64.3°; 36.2° versus 41.4°, respectively). No significant differences were observed for the other parameters. Significant correlations were found in both groups between LL and SS; PI and PT; and PI and SS. Conclusions Young adults with SN have associated SB modifications, particularly lower LL and SS values, when compared with a control group. This flatter profile resembles that observed in patients with lower back pain and early disc pathology. We believe that SNs are relevant clinical findings that should prompt the study of the SB of a patient, as it may uncover variations associated with early disc degeneration. Level of Evidence III.

The Influence of Schmorl Nodes in Spinal Sagittal Balance in Young Adults / A Influência dos nódulos de Schmorl no equilíbrio sagital de adultos jovens

Abstract Objectives The present study aims to characterize the spinal balance (SB) in young adults with Schmorl nodes (SN). Methods A cross-sectional study was conducted on a sample of 47 young adults. Lumbar magnetic resonance imaging (MRI) was used to divide the patients into an SN group and a control group. Standing full spine radiographs were used to compare the spinopelvic SB parameters between groups: sagittal vertical axis, thoracic kyphosis, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Results The LL and SS values were significantly lower in patients with SN when compared with the control group (54.5° versus 64.3°; 36.2° versus 41.4°, respectively). No significant differences were observed for the other parameters. Significant correlations were found in both groups between LL and SS; PI and PT; and PI and SS. Conclusions Young adults with SN have associated SB modifications, particularly lower LL and SS values, when compared with a control group. This flatter profile resembles that observed in patients with lower back pain and early disc pathology. We believe that SNs are relevant clinical findings that should prompt the study of the SB of a patient, as it may uncover variations associated with early disc degeneration. Level of Evidence III

Resumo Objetivos O presente estudo tem como objetivo caracterizar o equilíbrio sagital (SB, na sigla em inglês) espinhal em adultos jovens com nódulos de Schmorl (NS). Métodos Este é um estudo transversal de uma amostra composta por 47 adultos jovens. Ressonância magnética (RM) lombar foi usada para separar os pacientes em um grupo com NS e um grupo controle. Radiografias da coluna vertebral em pé foram usadas para comparar os parâmetros espinopélvicos do SB entre os grupos: eixo vertical sagital, cifose torácica, lordose lombar (LL), incidência pélvica (PI, na sigla em inglês), inclinação pélvica (PT, na sigla em inglês) e inclinação sacral (SS, na sigla em inglês). Resultados Os valores de LL e SS foram significativamente menores nos pacientes com NS em comparação com o grupo controle (54,5° versus 64,3°; 36,2° versus 41,4°, respectivamente). Não foram observadas diferenças significativas nos demais parâmetros. Os dois grupos apresentaram correlações significativas entre LL e SS, PI e PT e PI e SS. Conclusões Adultos jovens com NS apresentam modificações associadas ao SB, principalmente valores menores de LL e SS, em comparação com o grupo controle. Este perfil mais plano assemelha-se ao observado em pacientes com lombalgia e patologia discal em estágio inicial. Acreditamos que o NS seja um achado clínico relevante que deve levar ao estudo do SB de um paciente por poder revelar variações associadas aos primeiros estágios de degeneração discal. Nível de Evidência III

Advancing spinal fusion: Interbody stabilization by in situ foaming of a chemically modified polycaprolactone.

Spinal fusion (SF) surgery relies on medical hardware such as screws, cages and rods, complemented by bone graft or substitute, to stabilize the interventioned spine and achieve adequate bone ingrowth. SF is technically demanding, lengthy and expensive. Advances in material science and processing technologies, proposed herein, allowed the development of an adhesive polymeric foam with the potential to dismiss the need for invasive hardware in SF. Herein, 3D foams of polycaprolactone doped with polydopamine and polymethacrylic acid (PCL pDA pMAA) were created. For immediate bone stabilization, in situ hardening of the foam is required; therefore, a portable high-pressure device was developed to allow CO2 foaming within bone defects. Foams were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Adhesive properties of PCL pDA pMAA outperformed PCL when tested using glass surfaces (p < 0.001) or spinal plugs (p < 0.05). No cytotoxicity was observed, and bioactivity was confirmed by the CaP layer formed upon 7 days immersion in simulated body fluid. As proof of concept, PCL pDA pMAA was extruded in-between ex vivo porcine vertebrae, and micro-computed tomography revealed similar properties to those of trabecular bone. This novel system presents great promise for instrumentation-free interbody fusion.

Biomaterials and Bioactive Agents in Spinal Fusion.

Management of degenerative spine pathologies frequently leads to the need for spinal fusion (SF), where bone growth is induced toward stabilization of the interventioned spine. Autologous bone graft (ABG) remains the gold-standard inducer, whereas new bone graft substitutes attempt to achieve effective de novo bone formation and solid fusion. Limited fusion outcomes have driven motivation for more sophisticated and multidisciplinary solutions, involving new biomaterials and/or biologics, through innovative delivery platforms. The present review will analyze the most recent body of literature that is focused on new approaches for consistent bone fusion of spinal vertebrae, including the development of new biomaterials that pursue physical and chemical aptitudes; the delivery of growth factors (GF) to accelerate new bone formation; and the use of cells to improve functional bone development. Bone graft substitutes currently in clinical practice, such as demineralized bone matrix and ceramics, are still used as a starting point for the study of new bioactive agents. Polyesters such as polycaprolactone and polylactic acid arise as platforms for the development of composites, where a mineral element and cell/GF constitute the delivery system. Exciting fusion outcomes were obtained in several small and large animal models with these. On what regards bioactive agents, mesenchymal stem cells, preferentially derived from the bone marrow or adipose tissue, were studied in this context. Autologous and allogeneic approaches, as well as osteogenically differentiated cells, have been tested. These cell sources have further been genetically engineered for specific GF expression. Nevertheless, results on fusion efficacy with cells have been inconsistent. On the other hand, the delivery of GF (most commonly bone morphogenetic protein-2 [BMP-2]) has provided favorable outcomes. Complications related to burst release and dosing are still the target of research through the development of controlled release systems or alternative GF such as Nel-like molecule-1 (NELL-1), Oxysterols, or COMP-Ang1. Promising solutions with new biomaterial and GF compositions are becoming closer to the human patient, as these evidence high-fusion performance, while offering cost and safety advantages. The use of cells has not yet proved solid benefits, whereas a further understanding of cell behavior remains a challenge.

Long-term Follow-up of Dorsal Wedge Osteotomy for Pediatric Freiberg Disease.

BACKGROUND: Treatment for Freiberg disease has been largely conservative despite availability of various operative options for severe or refractory cases. The aim of this study was to evaluate the long-term results of pediatric patients with symptomatic Freiberg disease treated with intra-articular dorsal wedge osteotomy. METHODS: Pediatric patients treated for Freiberg disease with surgery between January 1982 and 1999 were identified and selected for long-term clinical evaluation. Patients were evaluated regarding operative satisfaction and clinical outcome, performed according to the American Orthopaedic Foot & Ankle Society (AOFAS) lesser toe metatarsophalangeal-interphalangeal scale and range of motion (ROM) of metatarsophalangeal (MTP) joint. Patients had radiographic assessment of degenerative joint status with anteroposterior and oblique foot x-ray. Twenty patients (18 female, 2 male; mean age 15.2 years; range 12-17 years) were identified. The mean follow-up period was 23.4 (range 15-32) years. RESULTS: The clinical outcomes of our patients were classified as excellent in 16 (80%) and good in 4 (20%). The AOFAS mean score was 96.8 (range 91-100) points at the last clinical appointment. A negative correlation between AOFAS score and time of follow-up (r's = -0.61, P < .001) was found. Also, a strong negative correlation was found between Smillie classification and AOFAS final score (r's = -0.88, P < .001). CONCLUSION: The patients were very satisfied with pain and quality of life at a mean follow-up time of 23.4 years. To our knowledge, this is the first long-term follow-up report supporting the procedure described by Gauthier and Elbaz as a good option for operative treatment of Freiberg disease. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Benefits of radial distortion correction in arthroscopic surgery: a first experimental study on a knee model.

BACKGROUND: Lens probes used in arthroscopy typically have a small diameter and wide field-of-view. This introduces strong radial distortion (RD) into the image, ultimately affecting the surgeon's hand-eye coordination. This study evaluates potential benefits of using distortion-free images in arthroscopic surgery. METHODS: Distortion-free images were obtained using RDFixer™ software (Perceive3D, SA) to remove RD in the input video stream. Twelve orthopedic residents performed an arthroscopic task (loose body removal) in a dry-knee model using video with and without distortion. Residents were questioned about image quality, and surgical performance was rated using an adapted Global Rating Scale. RESULTS: A statistically significant improvement of all parameters was observed with distortion-free images. Residents perceived distortion-free images as providing a wider field-of-view and a better notion of relative depth and distance. CONCLUSION: RD correction improved the surgical performance of residents, potentially decreasing their learning curve. Future work will study whether the benefits are observable in experienced surgeons. Copyright © 2014 John Wiley & Sons, Ltd.

Continuous zoom calibration by tracking salient points in endoscopic video.

Many image-based systems for aiding the surgeon during minimally invasive surgery require the endoscopic camera to be calibrated at all times. This article proposes a method for accomplishing this goal whenever the camera has optical zoom and the focal length changes during the procedure. Our solution for online calibration builds on recent developments in tracking salient points using differential image alignment, is well suited for continuous operation, and makes no assumptions about the camera motion or scene rigidity. Experimental validation using both a phantom model and in vivo data shows that the method enables accurate estimation of focal length when the zoom varies, avoiding the need to explicitly recalibrate during surgery. To the best of our knowledge this the first work proposing a practical solution for online zoom calibration in the operation room.

Spinal infection: state of the art and management algorithm.

INTRODUCTION: Spinal infection is a rare pathology although a concerning rising incidence has been observed in recent years. This increase might reflect a progressively more susceptible population but also the availability of increased diagnostic accuracy. Yet, even with improved diagnosis tools and procedures, the delay in diagnosis remains an important issue. This review aims to highlight the importance of a methodological attitude towards accurate and prompt diagnosis using an algorithm to aid on spinal infection management. METHODS: Appropriate literature on spinal infection was selected using databases from the US National Library of Medicine and the National Institutes of Health. RESULTS: Literature reveals that histopathological analysis of infected tissues is a paramount for diagnosis and must be performed routinely. Antibiotic therapy is transversal to both conservative and surgical approaches and must be initiated after etiological diagnosis. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and upon failure of conservative treatment. CONCLUSIONS: A methodological assessment could lead to diagnosis effectiveness of spinal infection. Towards this, we present a management algorithm based on literature findings.