Helton Luiz Aparecido Defino

A global perspective on the outcomes of surgical decompression in patients with cervical spondylotic myelopathy: results from the prospective multicenter AOSpine international study on 479 patients.

Study Design. Prospective, multicenter international cohort. Objective. To evaluate outcomes of surgical decompression for cervical spondylotic myelopathy (CSM) at a global level. Summary of Background Data. CSM is a degenerative spine disease and the most common cause of spinal cord dysfunction worldwide. Surgery is increasingly recommended as the preferred treatment strategy for CSM to improve neurological and functional status and quality of life. The outcomes of surgical intervention for CSM have never been evaluated at an international level. Methods. Between October 2007 and January 2011, 479 symptomatic patients with image evidence of CSM were enrolled in the prospective, multicenter AOSpine CSM-International study from 16 global sites. Preoperative and postoperative clinical status, functional impairment, and quality of life were evaluated using the modified Japanese Orthopaedic Assessment Scale, Nurick Scale, Neck Disability Index, and Short-Form-36v2. Preoperative and 12- and 24-month postoperative outcomes were compared using mixed-model analysis of covariance for repeated measurements. Results. The study cohort consisted of 310 males and 169 females, with a mean age of 56.37 ± 11.91 years. There were significant differences in age, etiology, and surgical approaches between the regions. At 24 months postoperatively, the mean modified Japanese Orthopaedic Assessment Scale score improved from 12.50 (95% confidence interval [CI], 12.24–12.76) to 14.90 (95% CI, 14.64–15.16); the Neck Disability Index improved from 36.38 (95% CI, 34.33–38.43) to 23.20 (95% CI, 21.24–25.15); and the SF36v2 Physical Component Score and Mental Composite Score improved from 34.28 (95% CI, 33.46–35.10) to 40.76 (95% CI, 39.71–41.81) and 39.45 (95% CI, 38.25–40.64) to 46.24 (95% CI, 44.94–47.55), respectively. The rate of neurological complications was 3.13%. Conclusion. Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and sociocultural determinants of health. Level of Evidence: 3

Treatment of fractures of the thoracolumbar spine by combined anteroposterior fixation using the Harms method

Abstract Forty-three patients with fractures of the thoracolumbar spine submitted to surgical treatment using the Harms method (dorsoventral operations) were studied prospectively with a follow-up of at least 12 months and evaluated on the basis of clinical and radiologic parameters and in relation to their professional activities. Thirty-five patients (81.3%) were males and eight (18.7%) females, ranging in age from 17 to 67 years (mean 34.08 ± 11.51 years). Seven patients (16.2%) presented fractures of more than one vertebra, and associated lesions were present in 15 patients (34.8%). Monosegmental fixation was performed in 7 patients (16.3%), bisegmental fixation in 29 (67.4%), and trisegmental fixation in 7 (16.3%). No patient was submitted to any type of external immobilization during the postoperative period and all patients were allowed to sit up in bed and to walk as soon as their clinical conditions permitted. Thirty-nine patients were followed up for a period ranging from 12 to 36 months (mean 16.58 ± 6.83 months). Four patients died during the postoperative period (three of pulmonary embolism and one of septicemia). Forty-two patients sat up in bed between the 2nd and 6th postoperative day, and those who did not present a disabling lesion (Frankel D or E) or other associated lesions walked between the 4th and 10th postoperative day (mean 6.14 ± 6.06 days). The neurological signs and symptoms improved in 16 patients (37.3%), were unchanged in 26 (60.4%), and worsened in 1 (2.3%). Twenty-three patients (87.5%) who had no neurological damage (Frankel E) returned to their professional activities after respective periods of disability of 1 month (three patients), 2 months (four patients), 3 months (one patient), 4 months (seven patients), 5–7 months (five patients), 8–12 months (one patient), and more than 12 months (three patients). The ability to work of the 24 patients without neurological damage was 100% in 21, 50% in 2, and zero in 1. The ability to walk of this group of patients was 1–5 km for 4 and more than 5 km for the remaining 20 patients. The complications observed were death (four patients; three cases of pulmonary embolism and one case of septicemia), infection (two patients), Stevens-Johnson syndrome (one patient), and meningitis (one patient). The mean kyphosis of the fractured segment was 22.17°± 10.97° preoperatively, 8.55°± 6.9° postoperatively, and 10.30°± 8.84° on the occasion of late evaluation. No loss of correction occurred in 28 patients (71.8%), a 5° loss was observed in 3 patients (7.6%), a 6° loss in 3 (7.6%), a 7° loss in 3 (7.6%), and a loss of more than 10° in 2 (5.2%).

Evaluation of rhBMP-2 and Natural Latex as Potential Osteogenic Proteins in Critical Size Defects by Histomorphometric Methods

This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein‐2 (rhBMP‐2) and a protein extracted from natural latex (Hevea brasiliensis, P‐1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty‐four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 μg of pure rhBMP‐2; (2) 5 μg of rhBMP‐2/monoolein gel; (3) pure monoolein gel; (4) 5 μg of pure P‐1; (5) 5 μg of P‐1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP‐2 allowed greater new bone formation than P‐1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 2010.

The effect of repetitive pilot-hole use on the insertion torque and pullout strength of vertebral system screws.

Study Design. In vitro biomechanical investigation of the screw-holding capacity. Objective. To evaluate the effect of repetitive screw-hole use on the insertional torque and retentive strength of vertebral system screws. Summary and Background Data. Placement and removal of vertebral system screws is sometimes necessary during the surgical procedures in order to assess the walls of the pilot hole. This procedure may compromise the holding capacity of the implant. Methods. Screws with outer diameter measuring 5, 6, and 7 mm were inserted into wood, polyurethane, polyethylene, and cancellous bone cylindrical blocks. The pilot holes were made with drills of a smaller, equal, or wider diameter than the inner screw diameter. Three experimental groups were established based on the number of insertions and reinsertions of the screws and subgroups were created according to the outer diameter of the screw and the diameter of the pilot hole used. Results. A reduction of screw-holding capacity was observed between the first and the following insertions regardless the anchorage material. The pattern of reduction of retentive strength was not similar to the pattern of torque reduction. The pullout strength was more pronounced between the first and the last insertions, while the torque decreased more proportionally from the first to the last insertions. Conclusion. Insertion and reinsertion of the screws of the vertebral fixation system used in the present study reduced the insertion torque and screw purchase.

Reconstruction of anterior iliac crest bone graft donor sites: presentation of a surgical technique

Abstract This study is a prospective evaluation of the reconstruction of anterior iliac crest bone graft donor sites using a technique developed by the authors. We present the technique and the initial results obtained with its use in 15 patients followed up for a period ranging from 6 to 16 months. Reconstruction of the iliac crest is performed using a rib, which is removed by an anterior approach to the spine. The rib is divided into two segments, which are fitted into the defect created in the iliac crest after removal of the bone graft. Clinical evaluation of the patients found a good cosmetic appearance of the reconstruction site, and the rib segments used showed good radiologic integration. Partial resorption of the segments was observed in two patients, with no effects on the cosmetic result.

Does age affect surgical outcomes in patients with degenerative cervical myelopathy? Results from the prospective multicenter AOSpine International study on 479 patients

Background In general, older patients with degenerative cervical myelopathy (DCM) are felt to have lower recovery potential following surgery due to increased degenerative pathology, comorbidities, reduced physiological reserves and age-related changes to the spinal cord. This study aims to determine whether age truly is an independent predictor of surgical outcome and to provide evidence to guide practice and decision-making. Methods A total of 479 patients with DCM were prospectively enrolled in the CSM-International study at 16 centres. Our sample was divided into a younger group (<65 years) and an elderly (≥65 years) group. A mixed model analytic approach was used to evaluate differences in the modified Japanese Orthopaedic Association (mJOA), Nurick, Short Form-36 (SF-36) and Neck Disability Index (NDI) scores between groups. We first created an unadjusted model between age and surgical outcome and then developed two adjusted models that accounted for variations in (1) baseline characteristics and (2) both baseline and surgical factors. Results Of the 479 patients, 360 (75.16%) were <65 years and 119 (24.84%) were ≥65 years. Elderly patients had a worse preoperative health status (p<0.0001) and were functionally more severe (p<0.0001). The majority of younger patients (64.96%) underwent anterior surgery, whereas the preferred approach in the elderly group was posterior (58.62%, p<0.0001). Elderly patients had a greater number of decompressed levels than younger patients (p<0.0001). At 24 months after surgery, younger patients achieved a higher postoperative mJOA (p<0.0001) and a lower Nurick score (p<0.0001) than elderly patients. After adjustments for patient and surgical characteristics, these differences in postoperative outcome scores decreased but remained significant. Conclusions Older age is an independent predictor of functional status in patients with DCM. However, patients over 65 with DCM still achieve functionally significant improvement after surgical decompression.

Behavioral and physiological methods for early quantitative assessment of spinal cord injury and prognosis in rats

Methods for reliable evaluation of spinal cord (SC) injury in rats at short periods (2 and 24 h) after lesion were tested to characterize the mechanisms implicated in primary SC damage. We measured the physiological changes occurring after several procedures for producing SC injury, with particular emphasis on sensorimotor functions. Segmental and suprasegmental reflexes were tested in 39 male Wistar rats weighing 250-300 g divided into three control groups that were subjected to a) anesthesia, b) dissection of soft prevertebral tissue, and c) laminectomy of the vertebral segments between T10 and L1. In the lesion group the SC was completely transected, hemisected or subjected to vertebral compression. All animals were evaluated 2 and 24 h after the experimental procedure by the hind limb motility index, Bohlman motor score, open-field, hot-plate, tail flick, and paw compression tests. The locomotion scale proved to be less sensitive than the sensorimotor tests. A reduction in exploratory movements was detected in the animals 24 h after the procedures. The hot-plate was the most sensitive test for detecting sensorimotor deficiencies following light, moderate or severe SC injury. The most sensitive and simplest test of reflex function was the hot-plate. The hemisection model promoted reproducible moderate SC injury which allowed us to quantify the resulting behavior and analyze the evolution of the lesion and its consequences during the first 24 h after injury. We conclude that hemisection permitted the quantitation of behavioral responses for evaluation of the development of deficits after lesions. Hind limb evaluation scores and spontaneous exploration events provided a sensitive index of immediate injury effects after SC lesion at 2 and 24 h. Taken together, locomotion scales, open-field, and hot-plate tests represent reproducible, quantitatively sensitive methods for detecting functional deficiencies within short periods of time, indicating their potential for the study of cellular mechanisms of primary injury and repair after traumatic SC injury.

Influência do diâmetro do orifício piloto na resistência ao arrancamento dos parafusos do corpo vertebral

SUMMARY Mechanical assays were performed in order to assess the influence of pilot hole diameter versus screw’s inner diameter on screw pullout resistance in the vertebral fixation systems applied to the vertebral body. The study was conducted in two stages. In the first, polyurethane test bodies were used for placing 5 and 6 mm screws, and, in the second stage, the screws were inserted into the lateral surface of the lumbar vertebral bodies of pigs. The pilot hole was built with drills with smaller, similar or larger diameter than screws’ inner diameter. Mechanical pullout assays were performed using a universal test machine for the assessment of maximum pullout screw resistance. The diameter of the pilot hole versus screw’s inner diameter was shown to influence screw pullout resistance.

Protective effects of cannabidiol on lesion-induced intervertebral disc degeneration.

Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content. Cannabidiol is the main non-psychotropic component of the Cannabis sativa with protective and anti-inflammatory properties. However, possible therapeutic effects of cannabidiol on intervertebral disc degeneration have not been investigated yet. The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI) and histological analyses. Disc injury was induced in the tail of male Wistar rats via a single needle puncture. The discs selected for injury were punctured percutaneously using a 21-gauge needle. MRI and histological evaluation were employed to assess the results. The effects of intradiscal injection of cannabidiol (30, 60 or 120 nmol) injected immediately after lesion were analyzed acutely (2 days) by MRI. The experimental group that received cannabidiol 120 nmol was resubmitted to MRI examination and then to histological analyses 15 days after lesion/cannabidiol injection. The needle puncture produced a significant disc injury detected both by MRI and histological analyses. Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.

Estudo comparativo da medida da rotação vertebral pelos métodos de Nash & Moe e método de Raimondi

Neste estudo foram avaliados a sensibilidade e precisao dos metodos de Nash e Moe e de Raimondi para a medida da rotacao da vertebra toracica e lombar.Tres cirurgioes de coluna avaliaram, independentemente, as radiografias de uma vertebra toracica (T9) e de uma vertebra lombar (L2) com graus de rotacao que variaram de 0o a 60o e estabeleceram valores de acordo com o metodo de Nash e Moe e o metodo de Raimondi.Foram estudadas a concordância entre os examinadores para um determinado metodo, a variacao das medidas obtidas na vertebra toracica e lombar a partir de uma mesma rotacao real conhecida e a correlacao entre um valor real conhecido de rotacao vertebral e a sua estimativa pelos metodos utilizados no estudo . Os resultados mostraram boa concordância entre os examinadores para o metodo de Nash e Moe, tanto para a vertebra toracica (k medio = 0,66), quanto para a lombar (k medio = 0,80). Pelo metodo de Raimondi nao houve diferenca significativa entre os examinadores para a vertebra toracica, no entanto, para a vertebra lombar houve baixa reprodutibilidade do metodo.Para uma mesma rotacao na vertebra toracica e lombar os resultados foram nao concordantes pelo metodo de Nash e Moe, e pelo metodo de Raimondi os valores observados para a vertebra toracica foram significativamente maiores que os da vertebra lombar. A correlacao entre os valores reais e as estimados pelo metodo de Raimondi para a vertebra toracica mostrou que houve diferenca significativa produzida em funcao da rotacao ate 20o graus, ja para a vertebra lombar, os valores obtidos foram muito proximos do real.