ObjectThe use of pedicle screws (PSs) for stabilization of unstable thoracolumbar fractures has become the standard of care, but PS efficacy has not been reported in the upper thoracic spine. The primary outcome of this study was to determine the efficacy of PS fixation to achieve and maintain reduction of unstable upper thoracic spine fractures (T1–5). Secondary outcomes included scores on a 1-year postoperative generic health-related quality of life (QOL) questionnaire and postoperative complications.MethodsThis study was a retrospective analysis and cross-sectional outcome assessment of cases prospectively entered into a spine database from 1997 to 2004. All patients with a traumatic, unstable upper thoracic spine (T1–5) fracture who underwent PS fixation were included. Preoperative CT scans with sagittal plane reformatted images were used to determine kyphotic deformity and compared with immediate postoperative and latest follow-up radiographs or CT scans. Patient charts, operative notes, and the results of postoperative follow-up examinations were reviewed. Patients were mailed the Short Form-36v2 (SF-36 version 2) by an independent study coordinator.ResultsCases involving 27 patients (23 male, 4 female) were evaluated. The patients' mean age was 39.9 years (range 16–73 years). In all, 251 PSs were passed between T-1 and T-8. The mean true kyphotic deformity was 18.2° preoperatively, 8.7° (p < 0.0005) initially postoperatively, and 10.1° at final follow-up (mean 2.3 years postoperatively). The mean SF-36 physical component summary score was 35.89 while the mental component summary score was 56.43 at a minimum of 1-year postoperatively (mean 3.2 years). There were no intraoperative vascular or neural complications.ConclusionsIn the hands of fellowship-trained spinal surgeons, PS fixation for reduction and stabilization of upper thoracic spine fractures is a safe and efficacious technique. Health-related QOL outcome data are deficient for spine trauma patients and should be an essential component of quantifying treatment outcomes.
Background/Objectives: Unilateral and bilateral cervical facet subluxations, dislocations, and/or fractures may be managed with anterior, posterior, or combined surgical approaches. The primary objective of this study was to identify radiographic features that predispose to poor radiographic outcomes (kyphosis) when these injuries are treated with single segment posterior cervical instrumentation and fusion. Method: A retrospective radiographic review was performed on 65 patients whose unilateral or bilateral facet subluxation/dislocations or fracture dislocation was managed with single segment posterior cervical instrumentation and fusion. The pre-and postoperative plain radiographs, CT, and MRI were assessed to identify the fracture type, degree of kyphosis, translation, and radiographic failure. Results: 2 patients (3.5%) demonstrated gross radiographic failure of the posterior instrumentation. Both had bilateral facet subluxation without fracture and ultimately required anterior revision. Kyphosis at follow-up was significantly correlated with kyphosis on the initial injury films (p = .007) and bilateral facet subluxation (p = .005). There was no correlation between follow-up kyphosis and the degree of preoperative translation, injury level, facet or endplate fracture, age, gender, or surgeon. There was no difference between the use of lateral mass plates or interspinous wires. Conclusion: This study confirmed a high union rate (96.5%) and satisfactory overall alignment with single segment posterior cervical instrumentation and fusion in these injuries. There is a high risk of poor postoperative sagittal alignment in patients with bilateral facet subluxation without fracture and in those with significant preoperative kyphosis. In patients with these high risk factors, a better radiographic result may be obtained with combined anterior and posterior surgery rather than with posterior fixation alone.
This paper investigated solid freeform fabrication(SFF) and microwave sintering processes of high strength HA porous scaffold. A newly developed SFF method called motor assisted micro-syringe freeform fabrication system was introduced to construct HA scaffolds. Sintering conditions that influenced the phases, microstructure and mechanical strength of scaffolds were discussed. Study of microstructure images and strength test results showed that densification and grain size were found to play an important role in determining the mechanical properties of sintered porous scaffolds, and microwave sintering process could get a sintered scaffold with small grain size and uniform structure more rapidly at lower sintering temperature than that of the conventional sintering. The fabricated HA scaffolds with controlled architecture (interconnected macro pore of 200-400μm, micro pore of 1-10μm within the rods) and improved mechanical properties (45.2MPa, 56.2% porosity ) may find potential applications in bone tissue engineering.
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