Unstable U-shaped sacral fractures and vertical shear Tile C pelvic ring disruptions are characterized by rare lesions occurring in patients with severe trauma. Because the initial damage-control resuscitation primarily aims to stop life-threatening bleeding, emergency treatment often includes an anterior external pelvic fixator. Delayed surgery is mandatory to allow early mobilization, reduce mortality, and improve functional outcomes. Regarding U-shaped sacral fractures, although Roy-Camille type 1 U-shaped sacral fractures can be treated with iliosacral screws, types 2 (posteriorly displaced, equivalent to AO Spine C3) and 3 (anteriorly displaced, equivalent to AO Spine C3) fractures require spinopelvic triangular fixation. Besides, proper reduction of type 2 and some type 3 sacral fractures is mandatory to prevent wound complications. In patients with neurological deficits, the need for sacral laminectomy is left at the discretion of the surgeon, given the indirect decompression already obtained with fracture reduction. Tile C pelvic disruptions with posterior ring injury located lateral to the sacral foramen can be treated with either iliosacral screws or triangular spinopelvic fixation, combined with anterior pelvic fixation. Conversely, Tile C pelvic disruptions with posterior ring injury located at, or medial, to the sacral foramen (Denis zone II or III) induce vertical lumbosacral instability and thus require spinopelvic triangular fixation with anterior pelvic osteosynthesis. Although minimally invasive techniques have been developed, open surgeries are still required for inexperienced operators and in case of major displacement. The complication rate reaches approximately 33.33% of the cases, and complications include hardware malposition, wound infection or dehiscence, hardware prominence, and sometimes hardware failure.

The Kernohan-Woltman notch phenomenon (KWNP) refers to an intracranial lesion causing massive side-to-side mass effect which leads to compression of the contralateral cerebral peduncle against the free edge of the cerebellar tentorium. Diagnosis is based on “paradoxical” motor deficit ipsilateral to the lesion associated with radiologic evidence of damage to the contralateral cerebral peduncle. To date, there is scarce evidence regarding KWNP associated neuroimaging patterns and motor function prognostic factors. A systematic review was conducted on Medline database from inception to July 2021 looking for English-language articles concerning KWNP, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The research yielded 45 articles for a total of 51 patients. The mean age was 40.7 years-old and the male/female sex ratio was 2/1. 63% of the patients (32/51) suffered from head trauma with a majority of acute subdural hematomas (57%, 29/51). 57% (29/51) of the patients were in the coma upon admission and 47% (24/51) presented pupil anomalies. KWNP presented the neuroimaging features of compression ischemic stroke located in the contralateral cerebral peduncle, with edema in the surrounding structures and sometimes compression stroke of the cerebral arteries passing nearby. 45% of the patients (23/51) presented a good motor functional outcome; nevertheless, no predisposing factor was identified. A Glasgow coma scale (GCS) of more than 3 showed a trend (p=0.1065) toward a better motor functional outcome. The KWNP is a regional compression syndrome oftentimes caused by sudden and massive uncal herniation and leading to contralateral cerebral peduncle ischemia. Even though patients suffering from KWNP usually present a good overall recovery, patients with a GCS of 3 may present a worse motor functional outcome. In order to better understand this syndrome, future studies will have to focus on more personalized criteria such as individual variation of tentorial notch width.