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STUDY DESIGN: A randomized, controlled follow-up study to review patients with acute thoracolumbar burst fractures treated by anterior instrumentation and reconstruction. OBJECTIVE: The objective of this study was to evaluate the results of anterior instrumentation in the treatment of thoracolumbar burst fractures and to determine whether anterior-only approach would be sufficient for highly unstable burst fractures. In this prospective follow-up study, we also compared the results of anterior reconstruction with structural grafting and with titanium mesh cage in a randomized fashion. SUMMARY OF BACKGROUND DATA: Anterior decompression and reconstruction supplemented with instrumentation is generally believed to be superior to fixation with posterior pedicle screw instrumentation for a highly unstable burst fracture, but the indications and methods for anterior approach has not been fully documented. METHODS: A total of 65 patients undergoing anterior plating for a thoracolumbar burst fracture with a load-sharing score of 7 or more between 2000 and 2003 were included this study. They were randomized to receive iliac crest autograft (group A, n = 32) or titanium mesh cages (group B, n = 33). The patients were similar in the distribution of 3-column injuries (n = 8 in group A vs. n = 9 in group B). During the minimum 4-year (range, 4-7 years) follow-up period, all patients were prospectively evaluated for clinical and radiologic outcomes. The Frankel scale, the ASIA motor score, and the Short Form 36 were used for clinical evaluation, whereas the fusion status and the loss of kyphosis correction for the local kyphosis angle were examined for radiologic outcome. RESULTS: All patients in this study achieved solid fusion, with significant neurologic improvement and no significant correction loss as defined by loss of kyphosis correction. The clinical and radiologic results were not significantly different (P > 0.05) at all time points between the 2 groups A and B. Twenty-six of 32 patients in group A still complained of donor site pain to some degree at the final follow-up. No significant impact of 3-column injuries (P > 0.05) were identified on the results for all comparisons. CONCLUSION: Anterior-only instrumentation and reconstruction with structural autograft or titanium mesh cages is sufficient for surgical treatment of thoracolumbar burst fractures with a load-sharing score of > or = 7 and even with 3-column injuries. [ABSTRACT FROM AUTHOR]

Study Design: A prospective, randomized clinical study comparing beta-tricalcium phosphate (beta-TCP) with autograft bone graft with follow-up of 3 years. Objective: To determine the efficacy of beta-TCP as a bone graft substitute combined with local autograft obtained from decompression compared with the use of autologous iliac crest bone graft in single-level instrumented posterolateral lumbar fusion. Summary Of Background Data: A variety of bone graft substitutes have been used in posterolateral lumbar fusion with different efficacy reported, but no controlled study was conducted on the clinical performance of beta-TCP in instrumented posterolateral lumbar fusion. Methods: Sixty-two patients with symptomatic degenerative lumbar spinal stenosis were treated with single-level instrumented posterolateral lumbar fusion. They were randomly assigned to fusion with beta-TCP combined with local bone obtained from the decompression (group A, n = 32) or autogenous iliac crest bone graft plus decompression bone (group B, n = 30). The patients were observed up for 3 years after surgery. The results were assessed clinically and radiographically. Results: There were no significant differences in recovery rate of Japanese Orthopedic Association score and SF-36 score at all time intervals. Successful radiographic fusion was documented in all patients in both treatment groups. All patients in group B, however, complained bone graft donor site pain although significant improvement of pain was observed during the follow-up. Conclusion: Instrumented posterolateral fusion with beta-TCP combined with local autograft results in the same radiographic fusion rates and similar improvement of clinical outcomes and life quality compared with autograft alone. The authors therefore recommend the use of beta-TCP as bone graft substitute for instrumented posterolateral fusion of lumbar spine to eliminate the need of bone grafting harvesting from the ilium. [ABSTRACT FROM AUTHOR]

Study Design: An in vitro biomechanical investigation. Objectives: The purpose of this study was to investigate the association between various load-sharing score and the acute flexibility of thoracolumbar fractures by measuring the 3-dimensional flexibility data. Summary Of Background Data: The load-sharing classification is a way to describe the injury severity of a spinal fracture and can be very useful in determining successful candidates for the choice of operative approaches. However, this classification needs to be validated by biomechanical and more clinical studies before its widespread use. To date, no biomechanical study was available. Methods: Eighteen fresh bovine T12-L3 specimens were harvested and divided into 3 groups, and subjected to axial compressive impact with 63.8, 107.8, and 137.2 J energy, respectively. Radiograph films and computed tomography scans of the experimental spine were taken in neutral posture after trauma. Multidirectional flexibility of each specimen was measured under flexion-extension, right/left lateral bending, and right/left axial rotation before and after trauma. The association between the multidirectional instabilities and the vertebral injuries to each of load-sharing point score was analyzed. Results: The load-sharing score of a fracture increased with the level of impact energy. Significant positive correlations were found between the load-sharing score and the motion parameters (average R = 0.434, average P = 0.004). Fractures with mild comminution (< or =6 points) showed more stability as compared to those with more comminution (> or =7 points) (P < or = 0.016). Conclusion: This study confirms that assessing the load-sharing score should be helpful in evaluating the acute instability of thoracolumbar fractures, and justifies the use of load-sharing classification in the thoracolumbar fractures. [ABSTRACT FROM AUTHOR]