BACKGROUND CONTEXT-Most previous studies have investigated ligaments mechanical properties at slow elongation rates of less than 25 mm/s.

Background-Previous clinical studies have identified the cervical facet joint, including the capsular ligaments, as sources of pain in whiplash patients. The goal of this study was to determine whether whiplash caused increased capsular ligament laxity by applying quasi-static loading to whiplash-exposed and control capsular ligaments.Methods-A total of 66 capsular ligament specimens (C2/3 to C7/T1) were prepared from 12 cervical spines (6 whiplash-exposed and 6 control). The whiplash-exposed spines had been previously rear impacted at a maximum peak T1 horizontal acceleration of 8 g. Capsular ligaments were elongated at 1 mm/s in increments of 0.05 mm until a tensile force of 5 N was achieved and subsequently returned to neutral position. Four pre-conditioning cycles were performed and data from the load phase of the fifth cycle were used for subsequent analyses. Ligament elongation was computed at tensile forces of 0, 0.25, 0.5, 0.75, 1.0, 2.5, and 5.0 N. Two factor, non-repeated measures ANOVA (P<0.05) was performed to determine significant differences in the average ligament elongation at tensile forces of 0 and 5 N between the whiplash-exposed and control groups and between spinal levels.Findings-Average elongation of the whiplash-exposed capsular ligaments was significantly greater than that of the control ligaments at tensile forces of 0 and 5 N. No significant differences between spinal levels were observed.Interpretation-Capsular ligament injuries, in the form of increased laxity, may be one component perpetuating chronic pain and clinical instability in whiplash patients.

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This study demonstrates that PACU images are inferior to intraoperative images and offer little or no incremental clinical utility for detecting issues with surgical construct placement after ACDF procedures. PACU imaging after ACDF procedures might be discontinued to realize savings in time, cost, and radiation exposure.

Spontaneous nerve torsion is a rare cause of nerve palsy. We describe a case of nerve torsion affecting the radial nerve in order to inform radiologists of the existence of this condition and subtle features on cross-sectional imaging that can suggest the diagnosis preoperatively.

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Abstract. We present a method for modeling tissue retraction during image-guided neurosurgery. A poroelastic brain model is driven by the stereoscopically-measured motion of a retractor to produce a full volume displacement field, which is used to update the preoperative MR images. Using the cortical surface surrounding the retractor as an independent evaluative landmark, we show that our approach is capable of capturing approximately 75% of the cortical deformation during tissue retraction.

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