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.

Treatment of Chronic Plantar Heel Pain With Radiofrequency Neural Ablation of the First Branch of the Lateral Plantar Nerve and Medial Calcaneal Nerve Branches.

From March 2012 to February 2013, 37 patients experiencing plantar heel pain for ≥6 months despite treatment with physical therapy and other conservative treatment modalities were followed up. If neurogenic heel pain originating from the first branch of the lateral plantar nerve was present, with or without the medial calcaneal nerve, diagnostic nerve blocks to these nerves were performed for confirmation. If the pain was determined to be of neurogenic origin, radiofrequency neural ablation (RFNA) was applied to the corresponding sensory nerve endings. Pain was evaluated using the visual analog scale, and patients were followed for at least one year. A total of 41 feet from 37 patients (30 [81.1%] females, 7 [18.9%] males; mean age, 50.7 ± 1.6 years; mean body mass index, 30.6 ± 0.7 kg/m(2)) were included. The mean visual analog scale scores improved significantly from 1 to 6 to 12 months after the procedure relative to before the procedure, with 88% of all patients rating the treatment as either very successful or successful at 12 months postoperatively. RFNA applied to both the first branch of the lateral plantar nerve and the medial calcaneal nerve sensory branches (16 [39%] feet) and only the first branch of the lateral plantar nerve sensory branches (25 [61%] feet) showed similarly high levels of success. Of the 41 feet, 28 [68.3%] had received extracorporeal shockwave therapy, 35 [85.4%] had received steroid injections, and 22 [53.7%] had received both extracorporeal shockwave therapy and steroid injections before RFNA as an index procedure. All were unresponsive to these previous treatments. In contrast, almost all (88%) were treated successfully with RFNA. Despite a high incidence of neurologic variations, with a precise diagnosis and good application of the technique using the painful points, chronic plantar heel pain can be treated successfully with RFNA.

Selective estrogen receptor modulation prevents scoliotic curve progression: radiologic and histomorphometric study on a bipedal C57Bl6 mice model.

PURPOSE: Previous work has suggested that progression of experimental scoliotic curves in pinealectomized chicken and bipedal C57BL6 mice models may be prevented and reversed with Tamoxifen treatment. Raloxifene is another Selective Estrogen Receptor Modulator (SERM) with estrogen agonist effects on bone and increases bone density but with fewer side effects on humans. To investigate whether scoliosis progression in bipedal C57Bl6 mice model could be prevented with SERM treatment and the mechanisms associated with this effect. METHODS: Eighty C57BL6 mice were rendered bipedal and divided into Tamoxifen (TMX), Raloxifene (RLX) and control groups. TMX and RLX groups received orally administered TMX and RLX for 40 weeks. Anteroposterior X-ray imaging and histomorphometric analysis (at 20th and 40th weeks) were performed. RESULTS: At 20th week, TMX and RLX groups displayed higher rates (p = 0.033, p = 0.029) and larger curve magnitudes (p = 0.018). At 40th week, curve rates were similar between the groups but the curve magnitudes in TMX and RLX groups were smaller (p = 0.001). Histomorphometry revealed that treated animals had higher trabecular density (p = 0.04), lower total intervertebral disc (p = 0.038) and growth plate volumes (p = 0.005) and smaller vertebral bodies (p = 0.016). CONCLUSIONS: Treatment with TMX or RLX did not reduce the incidence of scoliosis but decreased the curve magnitudes at 40 weeks. The underlying mechanism associated with the decrease in curve magnitudes may be the early maturation of growth plates, thereby possible deceleration of the growth rate of the vertebral column and increase in bone density. RLX is as effective as TMX in preventing the progression of scoliotic curves in melatonin deficient bipedal mice.

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.

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.

Titanium cage reconstruction of acetabular defects in revision hip arthroplasty results in favourable outcomes: up to 17 years follow-up.

INTRODUCTION: Titanium cages are valuable implant solutions in management of severe acetabular defects during total hip revisions. We aimed to report clinical and radiological results of our cases in which we used titanium cages for reconstruction of acetabular defects. METHODS: Patients underwent titanium cage reconstruction and bone grafting for their acetabular defects with minimum 2 year-follow-up are included to the study. Analysis of patient records, modified Hospital for Special Surgery hip score and radiological examinations on plain X-rays were evaluated. Acetabular defects are classified according to Paprosky's classification.Kaplan Meier survival analysis is performed. RESULTS: Fifty-six hips of 54 patients (2 bilateral) aged between 29-79 (mean 57 years ) are followed up for 7.06 years ±3.72 (2-17 years).Five patients required revision surgeries at a mean of 2.6±2.2 years. Kaplan Meier's analysis revealed a survival rate of 91,5 % and mean revision free duration was 15,66±0,56 years.HSS scores of the patients before revision surgery yielded a mean score of 27,9 ± 4,9 (14-38). HSS scores at final follow up showed a significant improvement at a mean score of 45,9 ± 7 (28-56) differences were statistically significant, p<0,001). DISCUSSION: Titanium cages are successful for restoring bone stock in severe acetabular defects. It is critical to pay attention on meticulous bone grafting of the presented defects and obtain good hip mechanics during cage insertion. Mechanical reasons are the leading cause of failure in long term but restoration of the bone stock and improvement in defect severity were regularly observed even in failed cages.

Center-edge angle values in healthy children between 5 and 14 years old in Turkey.

OBJECTIVE: The aim of this study was to determine the center-edge angle (CEA) values according to age, gender and side in healthy children between 5 and 14 years old in Turkey and to find out the angular limit values for mild and severe dysplasia. METHODS: The data pool that was gathered to investigate the frequency of hip dislocation in children between 6 months and 14 years old in Turkey was used. The data pool consists of pelvis and lower abdomen radiographs obtained for reasons other than hip dysplasia. Lower abdomen/pelvis radiographies of children between 5 and 14 years old were extracted from the data pool and were evaluated. Distribution of CEA values according to age, gender and side was examined. Measurements were performed by a single investigator on computer by using a standard method. Reliability of the measurements was tested by three different investigators on randomly selected films by using the standard method. RESULTS: CEA values of 3192 hips of 1596 children, who had no hip pathology, were measured. Mean CEA value was found as 26.2°±5.5°. The mean CEA was 26.2°±5.3° in males (%54) and 26.2°±5.7° in females (%46) (p=0.224). Mean values for the right and left hips were 25.7°±5.4° and 26.6°±5.6°, respectively. CEA value of 449 (14%) hips of 333 (20.8%) children was at the limit of mild dysplasia and CEA value of 70 (2.2%) hips of 58 (3.6%) children was at the limit of severe dysplasia. CEA values had increased by age and mild and severe dysplasia limits were determined for every age group. CONCLUSION: The mild and severe dysplasia values that are defined according to ages in Turkish population will guide the investigators in the diagnosis, follow-up and treatment planning of developmental dysplasia. LEVEL OF EVIDENCE: Level IV, Diagnostic Study.

The effect of calmodulin antagonists on scoliosis: bipedal C57BL/6 mice model.

C57BL6 mice are melatonin deficient from birth and have been shown to develop scoliosis when rendered bipedal. Our previous work suggested that tamoxifen and trifluoperozine may change the natural course of scoliosis in a chicken model. The objective of this study was to analyze whether the incidence of scoliosis or the magnitude of curves may be decreased by the administration of pharmacological agents tamoxifen or trifluoperozine in a mice scoliosis model. Sixty female 3-week-old C57BL6 mice underwent amputations of forelimbs and tails. Available 57 mice were divided into three groups, Group-I received no medications whereas Groups II and III received 10 mg TMX and 10 mg TMX + 10 mg TFP per liter of daily water supply, respectively. PA scoliosis X-rays were obtained at 20th and 40th weeks. Deformities were compared for incidence and the severity of the curves as well as disease progression or regression. At 20th week, overall, upper thoracic (UT), lower thoracic (T), and lumbar (L) scoliosis rates were similar (P = 0.531; P = 0.209; P = 0.926; P = 0.215, respectively) but thoraco-lumbar (TL) scoliosis rate was higher inTMX group (P = 0.036). However, at 40th week, although TL and L rates were similar (P = 0.628, P = 0.080), overall rate as well as the rates of UT and T scoliosis of TMX group were significantly lower (P = 0.001, P = 0.011, P = 0.001, respectively). As for curve magnitudes, T mean Cobb angle at 20th week was significantly higher in the C group (14 +/- 2.55) compared to TMX + TFP group (9 +/- 2.708; P = 0.033); at 40th week, TL mean Cobb angle was lower in the TMX + TFP group (17.50 +/- 3.45) compared to C (29.40 +/- 5.98; P = 0.031); and TMX group had lower TL Cobb angles compared to C (8.67 +/- 11.72) although not significant (P = 0.109). Double curve incidence at 40th week was significantly lower in TMX group compared to other groups (P = 0.001), triple curve incidence was lower in TMX + TFP and TMX groups, albeit not significant (P = 0.167). Between the 20th and 40th weeks, overall, double curve, and UT scoliosis rates showed an increase in C and TMX + TFP groups whereas TMX group showed a decline (P = 0.01, P = 0.002, P = 0.007, respectively). When specific regions were compared a similar significant difference was observed (P = 0.012 for upper thoracic; P = 0.018 for thoracic; P = 0.047 for thoraco-lumbar). This study has demonstrated that TMX is effective in changing the natural history of scoliotic deformities in C57BL6 mice model favorably.

Evaluation of shoulder balance in the normal adolescent population and its correlation with radiological parameters.

A descriptive clinical study in healthy adolescents was done to evaluate the clinical shoulder balance and analyze the correlation between clinical and radiological parameters which are currently used to evaluate shoulder balance. In addition to trunk shift and rib hump, shoulder balance is one of the criteria that are used to evaluate the outcomes in spinal deformity surgery. Several methods have been proposed to evaluate the shoulder balance in scoliotic patients; however, there is no uniformity to these methods in the current literature. Patients who applied to pediatric clinic without musculoskeletal pathology formed the patient population. Volunteers were asked to fill out a questionnaire assessing shoulder balance perception and had their clinical photograph taken simultaneously with a P-A chest X-ray. The clinical shoulder balance was evaluated through analysis of the clinical photograph. The X-rays were used to evaluate the radiological shoulder balance. The evaluated parameters included coracoid height difference (CHD), clavicular angle (CA), the clavicle-rib cage intersection difference (CRID), clavicular tilt angle difference (CTAD), and T1-tilt. The study group was composed of 48 male and 43 female patients with an average age of 13.6 +/- 2.1 (10-18) years. In the questionnaire, all patients stated that their shoulders were level. The digital photographs revealed that only 17(18.7%) adolescents had absolutely level shoulders. The average height difference between shoulders was 7.5 +/- 5.8 mm. The average CHD was 6.9 +/- 5.8 mm, average CA was 2.2 +/- 1.7 degrees , average CRID was 4.8 +/- 3.6 mm, average CTAD was 4 +/- 3.2 degrees , and average T1-tilt was 1.3 +/- 1.4 degrees . CHD, CA, and CRID demonstrated high correlation with clinical pictures, whereas CTAD demonstrated moderate and T1-tilt demonstrated only mild correlation. The radiological parameters used to evaluate the shoulder balance correlate with the clinical appearance. Contrary to popular belief, shoulder balance in healthy adolescents often does not exist.

[Treatment of thoracolumbar burst fractures using combined pedicle screw-laminar hook fixation]. / Torakolomber patlama kiriklarinin pedikül vidasi ve laminar kanca kombine tespiti ile tedavisi.

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.

Acetabular index values in healthy Turkish children between 6 months and 8 years of age: a cross-sectional radiological study.

OBJECTIVE: The aim of this study was to determine the normal acetabular index values in children between 6 months and 8 years of age based on sex, age and side and to define the cutoff values for mild and severe acetabular dysplasia. METHODS: The records collected from the data pool that was gathered to define the prevalence of untreated congenital hip dislocation in Turkish children between 6 months and 14 years of age was used. The acetabular index was measured on pelvic and abdominal radiographs of children between 6 months and 8 years of age, taken in 19 different cities for non-dysplasia related causes. The distribution of the index values based on age, sex and side. RESULTS: Thirty-three hips of 21 children (0.75%) out of 2788 children were found to be subluxated or luxated. Acetabular index values of 5534 hips of 2767 children were measured. Acetabular index values of 723 (13%) hips of 493 children (17.8%) were found to be between 1 and 2 standard deviations. Acetabular index values of 147 hips (2.65%) of 118 children (4.3%) were calculated to be above 2 standard deviations. There was a negative correlation between the acetabular index and age. CONCLUSIONS: The study defines the normal acetabular index values in healthy Turkish children between 6 months and 8 years of age and the expected acetabular index values for mild and severe dysplasia.

Long-segment posterior instrumentation and fusion with freeze-dried allograft in congenital scoliosis.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of long-segment posterior instrumentation and allograft application in obtaining fusion in congenital scoliosis. METHODS: Twenty-one patients with congenital scoliosis who were treated with long-segment posterior instrumentation (>6 levels) and freeze-dried allograft and followed up for more than 24 months were reviewed. Six patients were excluded from the study due to anterior procedures. Fifteen patients with congenital scoliosis (13 females, 2 males; mean age: 12.2 ± 3 years, range: 7-17 years) were retrospectively reviewed. Mean follow-up time was 30.9 ± 9.4 (range: 24 to 48) months. Six patients had laminectomy either due to previous posterior surgeries or to address intraspinal pathologies during the posterior fusion procedure. Preoperative, postoperative and final follow-up anteroposterior and lateral spine X-rays were reviewed. Fusion was graded according to the classification reported by Bridwell et al. RESULTS: Two patients were graded as 'no fusion' (pseudarthrosis), four patients as 'probably fused', and nine patients as 'definitely fused'. The major curve was corrected from an average of 68 ± 18.6 to 39.3 ± 12.2 degrees (p<0.001). Mean correction lost in the major curve was an average of 4.5 ± 5.2 degrees in the latest follow-up. There was significant correction in the compensatory curve (preoperative 37.9 ± 13.2 degrees, postoperative 20.2 ± 6.6 degrees; p=0.001). Preoperative and postoperative global thoracic kyphosis were 39.5 ± 13.3 and 32.3 ± 7.9 degrees, respectively (p=0.018). Preoperative and postoperative global lumbar lordosis was 36.3 ± 7.4 and 36.1 ± 8.9 degrees, respectively (p=0.883). Successful fusion was detected in %86.7 of patients in the final follow-up. CONCLUSION: The usage of allograft alone to achieve fusion increases the rates of pseudarthrosis while additional anterior procedure decreases the pseudarthrosis rate in patients with congenital scoliosis that require long-segment posterior instrumentation. Further studies should be performed to assess the efficacy of the usage of polysegment pedicle screw instrumentation.

Lumbopelvic fusion with a new fixation technique in lumbosacral agenesis: three cases.

PURPOSE: Patients with lumbosacral agenesis characteristically sit on their iliac wings with their torsos bent forward, which yields an increase in intra-abdominal pressure and, subsequently, negative effects on their diaphragm. The sacrum is not available as an anchor point for instrumentation. Dunn-McCarthy rods or Galveston fixations cannot be performed due to these limited anatomic properties. On the other hand, the absence of necessary bone mass for fusion anteriorly limits the fusion interventions to the posterior. Therefore, a secure and rigid fixation is essential to preclude the need for an external support. There are limited publications discussing different techniques due to the relatively rare incidence of the disease. We report the clinical and radiological results of a new technique applied to three patients in which previously recommended methods are modified. METHODS: Two 6-year-old female patients and one 5-year-old male patient with lumbosacral agenesis underwent posterior lumbopelvic instrumentation and fusion. Together with standard pedicle screw spinal instrumentation, pelvic fixation is obtained with a combination of supero-inferior directed rod and/or screw to overcome deforming forces created at the flexion-extension pivot points of the lumbopelvic junction. Autogenic anterior tibial cortical structural graft is used for laminopelvic bridging, and demineralized bone matrix is used for the augmentation of osteoinduction. A single leg hip spica is applied for 4 months to protect the fixation. RESULTS: Total correction yielded an aligned spine with a posture that allows for sitting on the ischial spines for all three patients. Solid fusion was observed to maintain this correction at the final follow-up. CONCLUSION: The use of new-generation pediatric spinal instrumentation systems with a new technique without knee disarticulation provides a safe and effective fixation and fusion in lumbosacral agenesis.

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.

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

BACKGROUND: An 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. METHODS: Fifty 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. RESULTS: Bone 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). CONCLUSIONS: This 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.

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.

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.

The effect of calmodulin antagonists on experimental scoliosis: a pinealectomized chicken model.

STUDY DESIGN: Randomized controlled. OBJECTIVE: To evaluate the effects of Tamoxifen (TMX) and trifluoperozine (TFP) on pinealectomized chicken scoliosis. SUMMARY OF BACKGROUND DATA: Pinealectomized chicken develops scoliosis probably due to the lack of melatonin. In addition to other functions, melatonin also acts as a calmodulin antagonist. We postulate that loss of this antagonistic effect may be the cause of scoliosis in this model. TMX and TFP are known calmodulin antagonists, which may alter the incidence and severity of scoliosis. METHODS: Seventy-two newly hatched chicken that underwent surgical pinealectomy within 72 hours of hatching were divided into 3 groups of 24 animals in each as group I (control), group II (TMX), and group III (TFP). TMX and TFP were given to groups II and III, respectively, for 10 weeks with the dose of 0.1 mg/kg/d, whereas the control group received no medication. AP scoliosis radiographs were obtained at seventh and 10th week to evaluate coronal spinal alignment. RESULTS: Three chickens in group I, 2 chickens in group II, and 1 chicken in group III died in the first postoperative week. Scoliosis incidences and magnitudes were similar among groups at seventh and 10th week. TMX and TFP groups showed decreases of incidence of upper cervical, lower cervical, lower cervical-thoracic-lumbar curves at 10th week compared with seventh week. TMX group showed a decline in thoracic region mean Cobb angle, whereas control group showed an increase (P = 0.048). TMX group showed a more prominent decline in cervicothoracic region mean Cobb angle compared with control group (P = 0.009). CONCLUSION: The incidence and magnitude of scoliosis in pinealectomized chicken may be decreased by the administration of TMX, presumably because of this drugs' calmodulin antagonism. Further studies on higher animals and dosage and timing are required.