Percutaneous interbody osteosynthesis in the treatment of thoracolumbar traumatic or tumoural lesions. A review of 51 cases

Extrusion of Biocompatible Osteoconductive Polymer (BOP) Causing Cervical Myelopathy

BACKGROUND

As the prevalence of spinal fusion surgery has increased, reliable and safe bone graft substitutes have been developed in response. Biocompatible osteoconductive polymer (BOP) has been used as a bone graft alternative for spine surgery. We present a case of cervical myelopathy due to extrusion of BOP 23 years after surgery and discuss the pathophysiology in terms of spinal fusion.

CASE DESCRIPTION

A 65-year-old man presented with a 3-month history of cervical myelopathic symptoms. Twenty-three years earlier, the patient had undergone cervical surgery for a C6-7 herniated disc with the use of BOP. Imaging studies of the cervical spine showed cord compression due to extruded BOP at C6-7. He underwent corpectomy of the C7 vertebral body and removal of the BOP for the neural decompression, combined with interbody fusion by use of an iliac bone graft and plate fixation. During the operation, crumbly fibers of the BOP were easily removed. His myelopathic symptoms improved immediately after surgery. Postoperative magnetic resonance imaging also showed successful decompression of the spinal cord. Histologically, a foreign body reaction and bony degeneration were found around the synthetic fibers of the BOP.

CONCLUSIONS

Spine surgeons should recognize the pathophysiology of the BOP used for spine fusion surgery. Although BOP is not currently used for spinal surgery, patients undergoing previous surgery with the BOP can present with related complications. Revision surgery is recommended to remove the unincorporated BOP and achieve solid spine fusion.

Non-operative vs. percutaneous stabilization in Magerl's A1 or A2 thoracolumbar spine fracture in adults: is it really advantageous for a good alignment of the spine? Preliminary data from a prospective study

PURPOSE

Percutaneous and non-operative stabilization are very controversial choices in the management of Magerl's A1 or A2 thoracolumbar spine fractures in adults. Our purpose is to figure out which of the two treatments is more suitable for the management and outcomes of these injuries.

METHODS

From 12/01/2011 to 06/30/2014 at the AO Orthopedics and Traumatology, Gaetano Rummo in Benevento, Italy, we treated 39 adult patients with thoracolumbar spinal fractures according to Magerl's A1 and A2. Twenty-four patients were treated with a 3-point orthopedic corset, and 15 patients were treated with percutaneous posterior stabilization without augmentation. The patients decided on treatment after extensive explanation of the pros and cons of the two treatments. The endpoint evaluation was set at the 6-month follow-up through the evaluation of the Visual Analogue Scale, Angle's Regional Kyphosis, Oswestry Low Back Pain Disability Questionnaire, and Denis work scale.

RESULTS

The preliminary results of this prospective study show that there is a considerable advantage in functionality and pain in treating adults suffering from thoracolumbar fractures with Percutaneous technique at the expense of the bust with three points.

CONCLUSIONS

Although the data are preliminary and based on data available in the literature, we can say that the Percutaneous posterior stabilization of thoracolumbar fractures in Magerl's A1 and A2 in adults is the ideal method for a good and functional alignment of the spine.

Early surgery for thoracolumbar spinal cord injury: initial experience from a developing spinal cord injury centre in India

The spinal cord injury centre of Nizam's Institute of Medical Sciences, Andhra Pradesh, India has been functioning now for 8 months and offers its services to the population of 80 million in the state. To date, 92 patients with a spinal cord injury have been treated; 51 had a thoracolumbar spinal injury. This report presents the results of the management of these 51 patients. Preoperatively both CT and MRI were performed and the radiological findings were correlated with outcome. Twenty five had a thoracic and 26 a lumber location. Twenty nine patients underwent surgical treatment (15 thoracic and 14 lumbar) and the others were treated conservatively (10 thoracic and 12 lumbar). All these operations were carried out within 2 weeks following trauma, and methylprednisolone therapy was instituted in those who reached the hospital early. Contraindications for surgery included a delay in admission of more than 3 weeks following trauma, a focus of sepsis, bedsores, a generalised bone disorder such as osteopenia, and medical illnesses. Transpedicular screw-plate fixation was performed in 27 patients, and two patients underwent decompressive laminectomy and interlaminar bone and wire fixation. Delayed spinal decompression was offered to one patient to relieve radiculopathy. Fracture-dislocation spinal injury and those with transection of the spinal cord had the worst outcome, whilst patients with a wedge compression fracture and cord oedema fared better. Operated cases had a shorter hospital stay, and complications of immobilisation were limited. Positive psychological influence of mobilisation and early acclimatisation to the altered style of living with their disability were the most significant outcomes following surgery.

BOP: biocompatible osteoconductive polymer: an experimental approach

BOP (biocompatible osteoconductive polymer) is a material proposed for osteosyntheses and for filling of bone defects in orthopaedics, neurosurgery and stomatology. It is a composite made of a copolymer of N-vinylpyrrolidone and methylmethacrylate, of polyamide-6 fibers and of calcium gluconate. The histological investigation includes the study of 30 intact rabbit femurs instrumented with a BOP rod, as well as the study of organs of the reticuloendothelial system. The currently available results show the absence of toxicity on hematopoietic tissue. Zones of osteoblastic activity surround the rods, coupled with an osteoclastic reaction which may result in the partial fragmentation of the polyamide fibers and its incorporation in the newly formed bone. We also observed the encapsulation of the material. The biomechanical approach investigated the mechanical properties of the material in bending and in shear. The radiological aspects of the investigation consisted of computerized axial tomography of the implanted femurs to measure density at the bone-implant interface.