Contemporary less invasive spinal instrumentation for AO C-type posterior pelvic ring injuries.

OBJECTIVE: This study evaluates efficacy and safety of contemporary spinal instrumentation for AO/type C posterior pelvic ring (PPR) injuries. METHODS: Twenty-two consecutive patients, aged 36 ± 17 years, were managed with spinal instrumentation with spinopelvic fixation (SPF) or non-spinopelvic fixation (NSPF) and less invasive surgery. There were 16 vertically unstable sacral fractures and six iliosacral dislocations. Matta score was used for fragment diastasis and Majeed's score for functional outcome evaluation. RESULTS: All patients were followed for 61 ± 8 months postoperatively. The operative time was less in NSPF (P < 0.001). SPF was applied in six cases and NSPF in 16 cases. Postoperatively, fragment diastasis was reduced from 16 ± 13 to 2.6 ± 3.8 mm (P < 0.000). There was no statistically significant difference in fracture reduction between SPF and NSPF (P = 0.16). Majeed score was 83 ± 16 postoperatively. There was a significant correlation between Matta score and Majeed score (P = 0.013). There were two cases with spinal instrumentation failure. Low-grade infection occurred in one patient, without hardware failure, that was eradicated after hardware removal. From ten patients with incomplete neurologic impairment on admission, eight showed postoperatively full and two partial recovery without direct sacral decompression. Patients with preoperative neurologic impairment showed lower postoperative Majeed score than those without neurologic impairment (P = 0.027). There was no correlation between neurologic impairment and recovery and type of PPR injury. CONCLUSIONS: SPF and NSPF with contemporary spinal instrumentation for C AO-type PPR injury with less invasive methods are safe and effective techniques that reduce and maintain PPR disruption allowing early mobilization, neurologic recovery and improved Majeed score. These slides can be retrieved under electronic supplementary material.

Optimization of a parallel permutation testing function for the SPRINT R package.

The statistical language R and its Bioconductor package are favoured by many biostatisticians for processing microarray data. The amount of data produced by some analyses has reached the limits of many common bioinformatics computing infrastructures. High Performance Computing systems offer a solution to this issue. The Simple Parallel R Interface (SPRINT) is a package that provides biostatisticians with easy access to High Performance Computing systems and allows the addition of parallelized functions to R. Previous work has established that the SPRINT implementation of an R permutation testing function has close to optimal scaling on up to 512 processors on a supercomputer. Access to supercomputers, however, is not always possible, and so the work presented here compares the performance of the SPRINT implementation on a supercomputer with benchmarks on a range of platforms including cloud resources and a common desktop machine with multiprocessing capabilities. Copyright © 2011 John Wiley & Sons, Ltd.