Carl Nunziato MD1, Geert A. Buijze MD PhD2, and David Ring MD PhD3 1Dell Seton Medical Center at the University of Texas at Austin, Austin, TX, USA 2Département de chirugie orthopédique et traumatologie, Montpellier, France 3Department of Surgery and Perioperative Care, Dell Medical School – The University of Texas at Austin, Austin, TX, USA Perilunate dislocations are usually treated with open reduction and it is not clear that computed tomography (CT) scanning or magnetic resonance imaging (MRI) helps with preparation or understanding of the injury beyond that gained with open visualization of the injury. Lateral and posteroanterior radiographs suggest a lesser arc perilunate injury without major fracture, but the anatomy is distorted and there are some bone fragments of unclear source. Despite the fact that posteroanterior and lateral radiographs are almost always sufficient to diagnose carpal dislocations, up to 25% of these injuries are missed at presentation, as shown by Herzberg et al. (level IV).1 One case report describes a delayed diagnosis of perilunate dislocation via ultrasonographic workup of median neuropathy (level V).3 Advanced imaging is not routine, but according to Kaewlai et al. (level V) CT with multiplanar and volumetric reformation can be a useful technique to demonstrate the complexity and extent of fractures and dislocations.2 There are no methodological studies comparing plain radiographs to ultrasound (US), CT imaging, MRI, or diagnostic arthroscopy for carpal dislocations.
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Carpal Dislocations
Clinical scenario
Top three questions
Question 1: In patients with perilunate dislocations, does advanced imaging (such as CT scan, US, MRI, or arthroscopy) lead to changes in diagnosis or operative planning compared to radiographs alone?
Rationale
Clinical comment
Available literature and quality of the evidence
Findings
Resolution of clinical scenario
Question 2: In patients with reducible perilunate dislocations, does delay in operative fixation lead to worse functional outcomes compared with early fixation?
Rationale