ePlasty: Vol. 16
Lunate Dislocation and Basic Wrist Kinematics
Maxwell Wingelaar, BS,a Patrick Newbury, BS,a Nicholas S. Adams, MDa,b and Andrew J. Livingston, MDa,b,c

aMichigan State University College of Human Medicine, Grand Rapids, Mich; bGrand Rapids Medical Education Partners Plastic and Reconstructive Surgery Residency, Grand Rapids, Mich; and cPlastic Surgery Specialists, Grand Rapids, Mich


Correspondence: nickadams18@gmail.com
Keywords: lunate dislocation, wrist kinematics, Mayfield classifications, carpal instability, progressive perilunate instability

DESCRIPTION

A 57-year old man presented to the emergency department for right wrist pain following a motorcycle crash. Physical examination revealed right wrist edema, pain with passive and active range of motion, and tenderness to palpation over the dorsal and volar wrist. Sensation was mildly diminished in the right thumb and the index and long fingers. X-rays of the right wrist were done (Figs 1a and 1b).

Figure 1. (a) Anteroposterior view of the right wrist demonstrating transradial styloid lunate dislocation. The lunate is seen overlapping the capitate, creating the classic “piece-of-pie” sign (white arrow). (b) Lateral view of the right wrist de .......