Murat Bezer

The use of screw at the fracture level in the treatment of thoracolumbar burst fractures.

Study Design In this prospective randomized study, the results of treating unstable thoracolumbar burst fractures by pedicle instrumentation with and without fracture level screw combination were given. Objective Our aim was to evaluate the efficacy of fracture level screw combination in achieving and maintaining correction in the treatment of unstable thoracolumbar burst fractures. Summary of Background Data Most authors reported that intraoperative correction of sagittal deformity is important for the maintenance of fracture reduction and is one of the most consistent predictor of satisfactory functional outcome. Methods Seventy-two patients with unstable thoracolumbar burst fractures were randomized into 4 groups with equal number of patients. In group 1, patients were treated by segmental posterior instrumentation with 2 levels above and 2 levels below the fracture level fixation, in group 2 they were treated as in group 1 with fracture level screw incorporation. In group 3, patients were treated by short-segment posterior instrumentation with 1 level above and 1 level below, in group 4 they were treated by short-segment posterior instrumentation with fracture level screw incorporation. Clinical and radiologic parameters were evaluated before surgery, after surgery, and at follow-up. Results The average follow-up was 50 months. Fracture level screw combination provided better intraoperative correction and maintenance in the treatment of unstable thoracolumbar burst fractures, which was more prevalent in short-segment fixation group. Conclusions Reinforcement with fracture level screw combination can help to provide better kyphosis correction and offers immediate spinal stability in patients with thoracolumbar burst fracture.

Transpedicular decancellation osteotomy in the treatment of posttuberculous kyphosis.

Objective Although the transpedicular decancellation osteotomy is a salvage technique for reconstruction of complex spinal deformities, it is not a procedure used exclusively for patients with kyphosis occurring as a sequel of treated tuberculosis. In this study, 16 adult patients with kyphosis underwent transpedicular decancellation osteotomy between 1993 and 1999. Pain, kyphosis angle, sagittal balance, and functional and neurologic status were the main parameters used for the clinical and radiologic assessment. Methods Sixteen patients with angular kyphotic deformity underwent transpedicular decancellation osteotomy between 1993 and 1999 with at least 5 years of follow-up. There were 6 male and 10 female patients with a mean age of 51.0. The radiologic involvement included the angle of kyphosis and plumb line on the anteroposterior and lateral radiographs. The preoperative and postoperative clinical assessment was performed by the using Oswestry Disability Index. All patients were asked to rate their preoperative and postoperative pain measurement using a pain visual analog scale. Fusion was evaluated on flexion-extension lateral radiographs. Results There were significant corrections in the kyphosis angle and the sagittal balance whereas no radiologic correction loss was observed in any of the patients during follow-ups. When the preoperative and the last follow-up pain visual analog scale and Oswestry Disability Index scores were compared, decrease was documented in both of them. Bony fusion was achieved in all patients and no neurologic complications were detected. Conclusions The transpedicular decancellation osteotomy effectively corrected the sagittal balance and improved pain and functional status. It was a safe and reliable technique in the treatment of posttuberculosis kyphosis.

Tuberculous spondylitis of the lumbosacral region: long-term follow-up of patients treated by chemotherapy, transpedicular drainage, posterior instrumentation, and fusion.

Objective: Tuberculosis spondylitis of the lumbosacral region has rarely been documented in the literature. We present an 87-month follow-up study of 7 of 62 patients with tuberculous spondylitis of the lumbosacral region treated by chemotherapy, transpedicular drainage, posterior instrumentation, and fusion. The purpose was to prove the hypothesis that chemotherapy with transpedicular drainage and single-stage posterior instrumentation-fusion is enough for the prevention of lumbar kyphosis and sagittal offset in selected cases. Methods: There were four men and three women, with average age of 53 years. All patients underwent transpedicular debridement, posterior fusion, and instrumentation. We studied the following data for consideration in these patients: most involved vertebra, vertebral body loss, progress of kyphosis, and sagittal offset. Results: The fourth lumbar vertebra was the most commonly involved vertebral segment. The average preoperative kyphosis was 17.5° and decreased to 5.4° postoperatively. Mean preoperative and postoperative sagittal offset was 0.34 mm and −5 mm, respectively. The average postoperative sagittal offset was increased from −5 to −2 mm at the third month and henceforth remained unchanged. There was no recurrent infection. Conclusion: We consider that transpedicular drainage, posterior instrumentation, and fusion constitute a less demanding operative technique for lumbosacral tuberculous spondylitis for the prevention of lumbar kyphosis and sagittal offset in patients without neurologic deficit and major vertebral body loss. This is the only lumbosacral tuberculous spondylitis series in which the patients were operated on with single-stage posterior surgery and merits a brief report in the light of the larger series.

Lateral shifting of the first metatarsal head in hallux valgus surgery: effect on sesamoid reduction.

Thirty feet with hallux valgus (HV) having grade 2 and 3 sesamoid stations on AP radiographs were examined after Lindgren-Turan oblique distal metatarsal osteotomy with a minimum follow-up of 12 months. Adductor tendon release from the lateral sesamoid was not performed to determine the isolated effect of distal metatarsal osteotomy on metatarsosesamoidal reduction. Of the 30 feet, 20 (67%) had reduced and 10 (33%) unreduced sesamoids at the follow-up. Ultimately, distal metatarsal osteotomy (DMO) with lateral shifting of the first metatarsal head more than 7.2 mm was found to reduce the sesamoids in the great majority of the cases (95% CI 7.243–9.757). Sesamoid release is redundant for metatarsosesamoidal reduction if sufficient lateral shift of the first metatarsal head over the sesamoids is accomplished.

The effect of an intramedullary implant with a static magnetic field on the healing of the osteotomised rabbit femur.

Static magnetic fields are a type of electromagnetic fields used in clinical practice. To ascertain what effect a static magnetic intramedullary device implanted in the rabbit femur had on fracture healing, 20 male New Zealand white rabbits with magnetic/nonmagnetic intramedullary implants were examined histologically, radiologically and for bone mineral density. Three groups were constituted according to the poles of the magnets. During surgery the intramedullary device was driven into the medulla. A femoral osteotomy was created with a mini Gigli wire at the centre point of the rod. Radiographs were obtained at the second and fourth weeks. Histological examination and bone mineral density were evaluated at the fourth week. The results of this study verified that an intramedullary implant with a static magnetic field improves bone healing in the first two weeks radiologically and that the configuration difference in magnetic poles has an effect on bone quality. Static magnetic fields have minor effects on bone mineral density values.

The influence of vertebral instability on peridural circulation and concomitant peridural fibrosis formation

An animal model of vertebral instability was used to analyze the effect of chronic lumbar instability on the peridural vasculature and fibrosis formation. Fifty mature male domestic rabbits were divided into five equal groups. The vertebral instability was performed by excision of supra and interspinous ligaments between L2-L3 and L3-L4, excision of transverse and spinous processes and making bilateral laminectomies and facetectomies in groups I, II, III and IV. In group V only para vertebral muscle dissection was performed without vertebral instability. The simulation of the long term effects of overuse model on unstable spines (chronic instability) were performed with the use of Electrical Neuromuscular Stimulator to simulate cyclic flexion–extension movement in groups I, II. The rabbits in group I and III were sacrified for the histological evaluation at postoperative fifth day. The rabbits in groups I II, IV and V were sacrified at postoperative 21st day. There was no peridural venous endothelial injury or stasis but there was an increased amount of polymorph nuclear leukocytes in both group I (unstable-overuse) and group III (unstable-no overuse) after sacrification at postoperative fifth day. Peridural fibrosis and also vascular changes with different grades were seen in group II, VI and V after sacrification at postoperative 21th day. The grade of the venous changes and the mean amount of peridural scar formation were prominently higher in group II (unstable-overuse) than in group IV (unstable-no overuse) and V (control group). There was no difference between group IV and V for peridural scar formation and vascular changes. In conclusion, the instability of the lumbar spine with overuse could be a cause of peridural venous circulatory impairment, resulting in fibrosis formation.

Transpedicular decancellation osteotomy in the treatment of peridural fibrosis.

Abstract From 1992 to 1997 a series of 12 multiply operated (averaging 2.5 previous operations) patients with recurrent peridural fibrosis and postlaminectomy kyphosis underwent surgery at our clinic. The surgery was designed to restore the physiological lordosis and relax tethered cord and epidural veins by transpedicular decancellation osteotomy at a vertebra other than the vertebra with peridural fibrosis. This paper presents the long-term functional outcome of these 12 patients. Clinical assessments were conducted pre-operatively and at 3-month intervals postoperatively and included X-ray assessment and evaluation of the patients’ functional status by Oswestry Disability Index (ODI) and of pain by visual analogue scale (pain VAS). All symptoms and the pain due to peridural fibrosis disappeared in the early postoperative period. Patients had lower disability and pain scores at their early and long-term follow-ups (follow-up period 24–74 months, mean 36.3 months). For patients with failed medical therapy for peridural fibrosis accompanied by lumbar kyphosis or hypolordosis, transpedicular decancellation osteotomy should be the surgical treatment of choice.

Magnetic Controlled Growing Rods (MCGR) As a Treatment of Early Onset Scoliosis (EOS): Early Results With Two Patients Had been Fused.

Study Design. Prospective unicentral nonrandomized study. Objective. To evaluate the safety and effectivity profile of magnetic controlled growing rods (MCGR) in patients with early onset scoliosis (EOS). Summary of Background Data. Conventional growing rods are the most commonly used growth sparring devices in the treatment of EOS, as this technique requires repeated surgical operations for lengthening; it is associated with high rate of complications and increased costs. MCGR in treatment of EOS is effective in correcting deformity whereas allowing continuous spinal growth as reported by a few studies. Methods. A total of 18 patients with progressive EOS were treated by MCGR, two of them had undergone final fusion operation. Patients were followed-up for a minimium time of 9 months from the time of initial surgery. Radiological data were analyzed in terms of Cobb angle, kyphosis angle, T1-T12, and T1-S1 distances in preoperative, postoperative, and last follow up. Results. The mean preoperative Cobb and kyphosis angle were 68° (44–116°) and 43° (98–24°), it was corrected to 35° (67–12°) and 29° (47–21°) immediately after initial operation and maintained at 34.5° (52–10°) and 33° (52–20°) at last follow up, respectively. The mean preoperative T1-T12 and T1-S1 distance were 171 mm (202–130 mm) and 289 mm (229–370 mm), it was increased to 197 mm (158–245 mm) and 330 mm (258–406mm) immediately after initial operation and further increased to 215 mm (170–260 mm) and 357 mm (277–430 mm) at last follow up, respectively. Two patients had undergone final fusion, they had overall mean Cobb angle correction of 66° (62–70°), and kyphosis angle change of 53° (26–80°). Total height gain in T1-T12 and T1-S1 of 80.5 mm (67–94 mm) and 119 mm (105–133 ), respectively. Conclusion. MCGR is safe and effective technique in correction of EOS deformity and in maintaining the correction during nonsurgical distraction procedures. A further correction of the deformity and more spinal height gain can be achieved in the final fusion operation. Level of Evidence: 3

Comparison of straight median sternotomy and interlocking sternotomy with respect to biomechanical stability.

AIM To increase the stability of sternotomy and so decrease the complications because of instability. METHODS Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costal joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-steel wiring. Fatigue testing was performed in cranio-caudal, anterio-posterior (AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s (0.2 Hz). The amount of displacement in AP, lateral and cranio-caudal directions were measured and also the opposing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm² for median sternotomy and was 16.8 ± 0.78 cm² for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1. CONCLUSION Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.

Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model

Study Design Mechanical study. Purpose To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Overview of Literature Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone–screw interface. Methods Polyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve. Results The peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation. Conclusions Expandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.