Percutaneous, PMMA-augmented, pedicle screw instrumentation of thoracolumbar ankylotic spine fractures.

INTRODUCTION: Fractures in the ankylotic spine may have an insidious presentation but are prone to displace with devastating consequences. The long lever arm of ankylosed spine fragments may lead to pulmonary and great vessel injury and is difficult to adequately immobilize. Conservative treatment will produce in many cases poor outcomes with high morbidity and mortality. Open surgical treatment is also fraught with technical difficulties and can lead to major blood loss and prolonged operative times. In recent years, percutaneous instrumentation of non-ankylotic spine fractures has gained popularity, producing similar outcomes to open surgery with shorter operative times and reduced blood loss and hospital length of stay. We describe our experience implementing these techniques in ankylotic spine patients. METHODS: We retrospectively retrieved from our hospital's electronic health records all patients treated for thoracolumbar spine fractures between 2008 and 2015 with a diagnosis of ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH). Operative and postoperative data, results, and complications were tabulated, and radiographic parameters were evaluated. RESULTS: Twenty-four patients with ankylotic spine disease underwent percutaneous augmented instrumentation between 2008 and 2015. The mean age was 76. All patients had at least one comorbidity. The mean number of ankylosed levels was 14. Mean operative time was 131 min. The average postoperative hemoglobin decrease was 1.21 gr/%, with only 4 patients requiring blood transfusion. 45.8% of the patients had postoperative medical complications. One patient (4.2%) had a superficial postoperative infection, and one patient died in hospital. The average hospital length of stay was 14.55 days. All patients retained their preoperative ASIA grades, and 3 improved one grade. All patients united their fractures without losing reduction. CONCLUSIONS: PMMA-augmented percutaneous instrumentation is an attractive surgical option for this difficult patient subset, especially when compared to other available current alternatives.

Nylon Skin Sutures Carry a Lower Risk of Post-Operative Infection than Metal Staples in Open Posterior Spine Surgery: A Retrospective Case-Control Study of 270 Patients.

Background: Controversy still exists regarding the optimal method for post-operative skin closure in orthopedic surgery. In total knee replacement, closure with metal staples is faster but carries a higher surgical site infection (SSI) risk. Other studies have found differing results in foot and ankle and hip surgery. Very little evidence exists on this subject after spine surgery. The aim of this study was to determine whether closure of the skin incision in open posterior spine surgery carries a different rate of post-operative SSI when using nylon sutures compared with metal staples. Methods: Up to 2006, virtually all skin incisions at our spine surgery unit were closed with metal staples and from 2006 onward with nylon sutures. This was a retrospective historical control study comparing the incidence of SSIs in patients operated on before (n = 127; staples) and after (n = 143; sutures) the transition date. Results: The staples group had an overall 11.8% combined deep and superficial infection rate whereas the nylon suture group had a 4.2% rate (p = 0.017). The two groups also differed in the type of antibiotic prophylaxis used, likelihood of incisional discharge, and the number of days the vacuum drains remained. Conclusions: In our departmental setting, closure of the skin incision with nylon sutures after open posterior spine surgery carried a significantly lower risk of post-operative SSI compared with metal staples. The generalizability of our findings is unclear, but they warrant further investigation.

Percutaneous augmented instrumentation of unstable thoracolumbar burst fractures.

BACKGROUND: Internal fixation of unstable thoracolumbar spine fractures requires correction of the lacking anterior column support. This usually entails insertion of a vertebral body replacement strut through an anterior approach, or a long posterior construct spanning at least two vertebrae above and two vertebrae below the fracture. Posterior short-segment pedicle instrumentation (SSPI)--one vertebra above and below--is suitable for approximately 40% of fractures, but not for all. METHODS: A total of 52 patients with unstable thoracolumbar burst fractures meeting our inclusion criteria were instrumented using a novel approach, combining percutaneous SSPI, pedicle screw augmentation with polymethyl methacrylate (PMMA) and fractured vertebra kyphoplasty. We retrospectively reviewed patient and fracture data, operative results and 1 year radiographic follow-up postoperatively in 40 of the patients. We reviewed operative complications of all 52 patients. RESULTS: Most fractures were AO/Magerl type A3.1, A3.2 and A3.3. They were instrumented within 72 h and ambulated without additional external bracing. Operative time averaged 2 h and blood loss was less than 50 cc in most cases. Complications were mostly related to PMMA leakage. On average, 3.3° (0-13) of correction was lost after 3 months, but remained constant afterward. CONCLUSIONS: Percutaneous augmented short-segment pedicle instrumentation of unstable thoracolumbar fractures can be done with short operative times, minimal blood loss and a low complication rate. The radiographical results at 1 year are equal to anterior stabilization and are better than other posterior-only techniques.

Cerebrospinal fluid leakage and pneumocephalus secondary to spine stab wounds.

Cerebro-spinal fluid leakage from a spinal stab wound is rare, and usually not a life-threatening injury. Pneumocephalus, a possible rare complication of traumatic cerebro-spinal fluid leakage, can potentially lead to intracranial hemorrhage and death. We describe two cases of spinal stab wounds complicated by cerebro-spinal fluid leakage, one of them developing into severe pneumocephalus. Both patients recovered completely with the following treatment protocol: (a) trendelenburg positioning of the patient, (b) insertion of a continuous-drainage cerebro-spinal fluid catheter into the lumbar thecal sac, (c) primary suture of the leaking skin wound, (d) IV antibiotic therapy.

Hyperbaric oxygen therapy for reduction of secondary brain damage in head injury: an animal model of brain contusion.

Cerebral contusions are one the most frequent traumatic lesions and the most common indication for secondary surgical decompression. The purpose of this study was to investigate the physiology of perilesional secondary brain damage and evaluate the value of hyperbaric oxygen therapy (HBOT) in the treatment of these lesions. Five groups of five Sprague-Dawley rats each were submitted to dynamic cortical deformation (DCD) induced by negative pressure applied to the cortex. Cerebral lesions produced by DCD at the vacuum site proved to be reproducible. The study protocol entailed the following: (1) DCD alone, (2) DCD and HBOT, (3) DCD and post-operative hypoxia and HBOT, (4) DCD, post-operative hypoxia and HBOT, and (5) DCD and normobaric hyperoxia. Animals were sacrificed after 4 days. Histological sections showed localized gross tissue loss in the cortex at injury site, along with hemorrhage. In all cases, the severity of secondary brain damage was assessed by counting the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and caspase 3-positive cells in successive perilesional layers, each 0.5 mm thick. Perilesional TUNEL positive cells suggested the involvement of apoptosis in group 1 (12.24% of positive cells in layer 1). These findings were significantly enhanced by post-operative hypoxia (31.75%, p < 0.001). HBOT significantly reduced the severity and extent of secondary brain damage expressed by the number of TUNEL positive cells in each layer and the volume of the lesion (4.7% and 9% of TUNEL positive cells in layer 1 in groups 2 and 4 respectively, p < 0.0001 and p < 0.003). Normobaric hyperoxia also proved to be beneficial although in a lesser extent. This study demonstrates that the vacuum model of brain injury is a reproducible model of cerebral contusion. The current findings also suggest that HBOT may limit the growth of cerebral contusions and justify further experimental studies.