Practice Easily Missed?

Perilunate dislocation

BMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e7026 (Published 06 November 2012) Cite this as: BMJ 2012;345:e7026
  1. Annakan V Navaratnam, foundation year 2 doctor,
  2. Simon Ball, hand surgery fellow,
  3. Claire Emerson, emergency medicine consultant,
  4. Rupert Eckersley, consultant hand surgeon
  1. 1Chelsea and Westminster Hospital, London SW10 9NH, UK
  1. Correspondence to: A V Navaratnam annakan.navaratnam04{at}imperial.ac.uk
  • Accepted 8 October 2012

A 30 year old, right hand dominant mechanic presented to the emergency department with a swollen, painful right wrist after he fell on to an outstretched right hand from a motorcycle travelling at high speed. Radiographs were interpreted as normal and the patient was discharged with a diagnosis of a wrist sprain. The next morning he presented again to the same emergency department with a new symptom: numbness of the right thumb and index, middle, and ring fingers. The radiographs were reviewed and a perilunate dislocation with median nerve compression was diagnosed. That afternoon the patient had median nerve decompression and open reduction and stabilisation of the perilunate dislocation with ligament repair.

What are perilunate and lunate dislocations?

Perilunate dislocations usually result from high energy hyperextension injuries to the wrist. In perilunate dislocations, the capitate and other carpal bones are displaced dorsal to the lunate, which remains located in the lunate fossa of the distal radius (fig 1). Lunate dislocation is the final stage in the continuum of perilunate dislocation and refers to the volar displacement of lunate from the lunate fossa of the distal radius.1

Fig 1 Left: Anteroposterior diagram of the right wrist and median nerve. Right: Cross section of the right wrist showing the relation of the carpal bones and median nerve. In the wrist the median nerve passes through the carpal tunnel along with nine flexor tendons. The carpal tunnel is situated volar to the lunate and scaphoid. Owing to its close proximity to the median nerve, displacement of the lunate in a perilunate dislocation can exert pressure on the median nerve that may result in nerve injury

How common is perilunate dislocation?

  • Perilunate dislocation is a rare presentation

  • Associated with scaphoid fractures in 61% of cases1

Why is perilunate dislocation missed?

A case series on the management of neglected perilunate dislocation described 10 cases managed in a single …

Sign in

Subscribe