Ibrahim Akel

Comparison of the melatonin and calmodulin in paravertebral muscle and platelets of patients with or without adolescent idiopathic scoliosis.

Study Design. Controlled clinical study. Objective. To compare muscle and platelet calmodulin and melatonin concentrations of scoliotic and nonscoliotic populations. Summary of Background Data. Melatonin and calmodulin are potential key molecules in scoliosis etiology. Calmodulin is not only a second messenger of melatonin but also has been shown to have effects on muscle contractility. There is a possibility that it may be of importance in the regulation of spinal alignment. Platelets have been defined as mini muscles calmodulin and melatonin levels of which may be the projections of muscle values. Methods. Twenty patients undergoing posterior surgery for adolescent idiopathic scoliosis (AIS) and 9 thoracic-lumbar trauma patients undergoing posterior surgery constituted the population. Autologous bloods were collected and processed to obtain platelets. Paravertebral muscle tissue samples from both sides were obtained at T12–L1 level intraoperatively. Muscle and platelet samples were analyzed for the levels of melatonin by radio immuno assay and for calmodulin by enzyme-linked immunosorbent analysis. Groups, concave (left side for the control group) and convex side (right side for the control group), muscles and platelet median protein concentrations, and optic densitometry (OD) ratio values were compared. Results. AIS group consisted of 2 male and 18 female patients. Mean age was 16.1 ± 3.78 (11–29). Control group consisted of 5 male and 4 female patients. Mean age was 35 ± 13.47 (16–55). Platelet Calmodulin OD/Supernatant’s OD ratios and both convex and concave sides’ muscle Calmodulin OD/Supernatants’ OD ratios were not different between groups. On the other hand, convex side muscle calmodulin to total muscle calmodulin ratios were higher in AIS group compared with concave (P = 0.048); likewise, concave side calmodulin to total calmodulin ratios were lower in AIS group compared with control (P = 0.035). Convex side calmodulin to concave side calmodulin ratios were significantly different among groups (P = 0.048). Neither platelet melatonin to total protein ratios, nor convex or concave side muscle melatonin to total protein ratios, nor convex to concave side melatonin ratios were significantly different between groups. Convex or concave side calmodulin or melatonin values were not correlated with platelet values. Conclusion. AIS group had an asymmetric distribution of calmodulin in paraspinal muscle, higher at the convex side and lower at the concave. Neither platelet melatonin nor platelet calmodulin was found to be representative of the muscle protein values.

Is decreased bone mineral density associated with development of scoliosis?A bipedal osteopenic rat model

BackgroundAn association between adolescent idiopathic scoliosis and osteopenia has been proposed to exist. It is still not clear whether there is such an association and if so, whether osteopenia is a causative factor or a consequence. Our previous pilot studies have suggested the presence of osteopenia in scoliotic animals. The aim of this study was to investigate the development of scoliosis in an unpinealectomized bipedal osteopenic rat model, implementing osteoporosis as a causative factor.MethodsFifty Sprague-Dawley rats were rendered bipedal at the 3rd postnatal week and separated into control (25 rats) and heparin (25 rats receiving 1 IU/gr body weight/day) groups. DEXA scans after 4 weeks of heparin administration showed low bone mass in the heparin group. Anteroposterior and lateral x-rays of the surviving 42 animals (19 in heparin and 23 in control groups) were taken under anesthesia at the 40th week to evaluate for spinal deformity. Additional histomorphometric analysis was done on spine specimens to confirm the low bone mass in heparin receiving animals. Results of the DEXA scans, histomorphometric analysis and radiological data were compared between the groups.ResultsBone mineral densities of rats in the heparin group were significantly lower than the control group as evidenced by both the DEXA scans and histomorphometric analyses. However, the incidence of scoliosis (82% in heparin and 65% in control; p > 0.05) as well as the curve magnitudes (12.1 ± 3.8 in heparin versus 10.1 ± 4.3 degrees in control; p > 0.05) were not significantly different. Osteopenic rats were significantly less kyphotic compared to control specimens (p = 0.001).ConclusionsThis study has revealed two important findings. One is that bipedality (in the absence of pinealectomy) by itself may be a cause of scoliosis in this animal model. Further studies on animal models need to consider bipedality as an independent factor. Secondly, relative hypokyphosis in osteopenic animals may have important implications. The absence of sagittal plane analyses in previous studies makes comparison impossible, but nonetheless these findings suggest that osteopenia may be important in the development of 3D deformity in adolescent idiopathic scoliosis.

Safety and efficacy of instrumented convex growth arrest in treatment of congenital scoliosis.

Background: Anterior and posterior convex hemiepiphysiodesis is a widely used surgical alternative in the treatment of congenital scoliosis. This procedure has the disadvantage of the need for both anterior and posterior approaches. Furthermore, outcomes may be unpredictable. Posterior convex growth arrest (CGA) with pedicle screws at each segment on the convex side may obviate the need for anterior surgery and provides more predictable outcomes. This study retrospectively evaluates the safety and efficacy of instrumented posterior CGA in congenital scoliosis. Methods: Patients who had posterior CGA with convex pedicle screw instrumentation for congenital scoliosis were evaluated retrospectively. Thirteen patients (6 male, 7 female) were included in the study. Preoperative, early postoperative, and last follow-up standing posteroanterior and lateral x-rays were evaluated. Cobb angles were recorded for the instrumented segment (main curve). Global thoracic kyphosis was measured between T2 and T12 on sagittal plane. These values were compared preoperatively, postoperatively, and at last follow-up. The T1-S1 vertical height and the height between the concave side pedicles of the upper and lower end vertebra of the main curve was also determined and recorded as the concave height. Results: The average follow-up was 56.1±10 months (range, 36 to 74 mo) and the average age of the patients at the time of operation was 64.5±30.1 months (range, 15 to 108 mo). All patients were Risser zero at the time of surgery. The average curve magnitude was 49±10.9 degrees (range, 34 to 68 degrees) preoperatively, 38.3±9.7 degrees (range, 28 to 58 degrees) early postoperatively, and 33.5±12.4 degrees (16 to 52 degrees) at last follow-up. There was a significant difference between the preoperative and early postoperative main curve Cobb angle measurements (P=0.001). The average concave height was 94.2±20.2 mm in the early postoperative period and 104.7±21.7 mm at last follow-up (P=0.003). The average T1-S1 height was 292.1±67.1 mm in the early postoperative period and 363.9±94.5 mm at last follow-up (P=0.005). There was at least ≥5 degrees improvement in 9 of the 12 patients in the follow-up period after the index procedure. In 3 patients, the curve did not change and the correction was maintained. Curve progression was observed in 1 patient due to a technical error. There were no wound infections or instrumentation failures during follow-up. Conclusions: Instrumented CGA can safely be used in long sweeping curves of immature spines. Using this technique; thoracotomy, anterior procedure, and 2-stage surgery can be avoided. Moreover, it guarantees some degree of correction in all patients because of the instrumentation effect, eliminating the unpredictable nature of classic CGA. Level of Evidence: Therapeutic level IV study.

Growth modulation in the management of growing spine deformities

The Hueter–Volkmann law explains the physiological response of the growth plate under mechanical loading. This law mainly explains the pathological mechanism for growing long-bone deformities. Vertebral endplates also show a similar response under mechanical loading. Experimental studies have provided information about spinal growth modulation and, now, it is possible to explain the mechanism of the curvature progression. Convex growth arrest is shown to successfully treat deformities of the growing spine and unnecessary growth arrest of the whole spine is prevented. Both anterior and posterior parts of the convexity should be addressed to achieve a satisfactory improvement in the deformity, albeit epiphysiodesis effect cannot be stipulated at all times. Anterior vertebral body stapling without fusion yielded better results with new shape memory alloys and techniques. This method can be used with minimally invasive techniques and has the potential advantage of producing reversible physeal arrest. Instrumented posterior hemiepiphysiodesis seems to be as effective as classical combined anterior and posterior arthrodesis, where it is less invasive and morbid. Convex hemiepiphysiodesis with concave-side distraction through growing rod techniques provide a better control of the curve immediately after surgery. This method has the advantages of posterior instrumented hemiepiphysiodesis, but necessitates additional surgeries. Concave-side rib shortening and/or convex-side lengthening is an experimental method with an indirect effect on spinal growth. To conclude, whatever the cause of the spinal deformity, growth modulation can be used to manage the growing spine deformities with no or shorter segment fusions.

Prevalence of untreated hip dislocation in Turkish children aged 6 months to 14 years

OBJECTIVE In this study, our aim was to determine the prevalence of untreated hip dislocation and subluxation in Turkey. METHODS Pelvic radiographs of 4,947 children, aged between 6 months and 14 years, taken for non-orthopedic purposes were requested from 23 provinces around the country. 3,723 radiographs met the study criteria and were evaluated. Dislocated and subluxated hips were identified according to the relationship of femoral head using Perkins line and quadrants. RESULTS Thirty-five hips in 22 children were found to be dislocated or subluxated. The prevalence rate was calculated as 5.9% CONCLUSION Despite appearing to have decreased when compared to limited regional prevalence studies, hip dislocation and subluxation prevalence is still unacceptably high. More extensile work should be done to avoid external factors in the etiology of developmental dysplasia of the hip and to organize screening programs in newborns.

Treatment of thoracolumbar burst fractures using combined pedicle screw-laminar hook fixation

OBJECTIVE The aim of this study was to evaluate the mid-term outcome of pedicle screw-laminar hook (PS-LH) fixation in the surgical treatment of thoracolumbar burst fractures. METHODS Nineteen patients (12 male, 7 female; mean age: 34.4 years, range: 19 to 57 years) with thoracolumbar burst fractures treated using PS-LH between 1996 and 2006 were evaluated. The 17 patients (11 male, 6 female) who had a minimum of 2 years follow-up were included in the study. Radiographic outcome was evaluated by measuring the local kyphosis angle (LKA) and anterior vertebral height (AVH). Mean follow-up was 81 (range: 38 to 122) months and 15 patients completed more than 5 years of follow-up. RESULTS Preoperative vertebral height loss and LKA of 41.2% (range: 29% to 64%) and 16.8° (range: 5° to 36°), respectively, were corrected to 16.3% (range: 0% to 44%) and -1.2° (range: -17° to 10°), respectively, after the operation. Mean losses of correction for vertebral height and local kyphosis were 1.8 ± 7.9% and 4.3 ± 7.1 degrees, respectively, at the 2-year follow-up and -1.8 ± 4.5% and 0.5 ± 1.5 degrees, respectively, between 2 years and 5 years. Loss of correction was significant for the LKA (p=0.023) but not for vertebral height (p=0.360). Five patients had losses of correction of more than 5 degrees. Changes between 2 and 5 years were not significant for vertebral height loss and local kyphosis (p=0.147 and p=0.205, respectively) and remained improved when compared with the preoperative values (p<0.001). Average SF-36 scores of the 15 patients evaluated at the final follow-up were comparable with the general Turkish population. CONCLUSION The PS-LH construct provided a significant correction of the local kyphotic deformity. Augmentation of the upper and lower pedicle screw by the sublaminar hook did not completely prevent correction loss but was found to stabilize at the 5th year of follow-up without any clinical problems.

Convex Hemiepiphysiodesis: Posterior/anterior in-situ Versus Posterior-only With Pedicle Screw Instrumentation: An Experimental Simulation in Immature Pigs.

Study Design: Experimental study. Background: Convex growth arrest (CGA) has been commonly used in the treatment of long-sweeping congenital deformities of the immature spine. As there are major drawbacks about the anterior procedure in the conventional CGA method, a new modification has been documented that using only posterior spinal approach with pedicle screw instrumentation. The aim of the study was to compare posterior-only CGA using pedicle screws with combined anterior/posterior in-situ CGA for the findings in histologic, radiologic, and manual palpation examinations in an immature pig model. Methods: Twelve 10-weeks old pigs were grouped into 2. In group 1, posterior-only, pedicle screw instrumented CGA was performed on the left side of L1-L4 vertebrae. In group 2, conventional combined posterior and anterior CGA was performed to the left side of L1-L4 vertebrae without instrumentation. All animals were killed twelve weeks after surgery. T11-L5 segments were en-bloc resected and radiologic, histologic, and manual palpation examinations were done. Results: Marked scoliotic (12.2±2.5 and 9.2±1.3 in group 1 and 2, respectively) and kyphotic (11.2±1.0 degrees for the group 1 and 12±5.2 degrees for the group 2, respectively) deformities were noted in both groups, which were caused by hemiepiphysiodesis effect. Anterior and posterior parts of group 2 and posterior part of group 1 demonstrated fusion in histologic and radiologic analyzes. In anterior part of the group 1, marked narrowing on the disk spaces and thinning of growth plates were noted in radiologicg examination, chondrocyte degeneration, and newly-formed bone trabeculae in disk-space were noted in histological examination. In manual palpation, no motion was detected in group 1 and motion was detected in only one segment of one animal in group 2. Conclusions: Anterior growth of the vertebrae can be controlled by application of posterior transpedicular screws and rod. Such an effect can eliminate the need for anterior surgical intervention in convex hemiepiphysiodesis procedures. Clinical Relevance: The instrumented CGA technique provides a satisfactory epiphysiodesis effect both anteriorly and posteriorly, as previously demonstrated by clinical studies.

Transverse sacral fractures and concomitant late-diagnosed cauda equina syndrome.

Transverse sacral fractures in young patients occur with high-energy mechanisms. Because of the drawbacks in radiographic and neurologic evaluations of the sacral area in polytrauma patients, misdiagnosis is quite common. In this study, we aimed to report our clinical results in three patients with displaced transverse sacral fractures compromising the sacral canal and concomitant late-diagnosed (at least 48 hours) cauda equina syndrome. Bilateral lumbopelvic fixation, followed by sacral laminectomy and decompression, was performed in all patients. Despite the late- diagnosed cauda equina syndrome, we observed that surgical decompression and lumbopelvic fixation had positive effects on neurologic recovery, pain relief and early unsupported mobilization.

Lumbar Injuries in Pediatric Athletes

Sports injuries of pediatric athletes increase in number, as sports activities are becoming more popular among children. Lumbar injuries are thought to be around 10% of all sports-activity-related injuries in pediatric athletes. Overuse injuries, pars problems, spondylolysis, spondylolisthesis, intervertebral disk herniations, and sacroiliac joint problems are the most common problems in pediatric athletes. Activity level, types of forces created during the activity, anthropometric parameters of the athlete, and growth plate endurance are important factors in the understanding of the injury mechanisms.