CASE REPORT

Dislocation of the carpal scaphoid: A case report

Jayant Arora a,*, Anand Pillai b

Injury Extra (2006) 37, 184—186

www.elsevier.com/locate/inext

aNorth Tyne-Side General Hospital, North Shields, UKbWestern Infirmary, Glasgow, UK

Accepted 2 November 2005

Case report

A 32-year-old motorcyclist presented to the emer-gency department after sustaining an injury to hisright dominant wrist in a road traffic accident on thesame day. He complained of pain, swelling anddeformity of the right wrist. Examination of theright wrist revealed swelling, tenderness, ulnardeviation deformity and a palpable prominence overthe radial aspect of the wrist without any neuro-vascular deficit. Radiographs (Figs. 1 and 2)revealed a radiopalmar dislocation of the scaphoid,avulsion fractures of the radial and ulnar styloidprocesses and a small chip fracture from the trique-trum. Diastasis between the capitate/hamate andmiddle/ring metacarpals was also evident, suggest-ing a disruption of the distal carpal row. A minimallydisplaced intra-articular fracture of the distal radiuswas also seen.

Under a general anaesthetic, the dislocation wasreduced by longitudinal traction, ulnar deviationand direct pressure on the bony prominence asthe wrist was brought into neutral position. Anato-mical reduction was confirmed under fluoroscopicexamination. Two smooth K-wires were drilled tohold the reduction, one between scaphoid andlunate and one to hold the intra-articular fracturefragments of the distal radius (Fig. 3). A below-

Figure 1 Pre-operative X-rays showing posterior—ante-rior (PA) view of the wrist.

* Corresponding author at: 225 Addycombe Terrace, Heaton,Newcastle upon Tyne NE6 5TY, UK. Tel.: +44 7984 828 645.

E-mail address: arorajayant@yahoo.com (J. Arora).

1572-3461/$ — see front matter. Crown Copyright # 2005 Published by Elsevier Ltd. All rights reserved.doi:10.1016/j.injury.2005.11.002

Dislocation of the carpal scaphoid: A case report 185

Figure 2 Pre-operative X-rays showing lateral view ofthe wrist.

Figure 3 Post-operative X-rays showing PA and lateralviews.

Figure 4 X-rays at 16 months follow up.

elbow thumb spica cast was applied postoperatively.Pins were removed after 6 weeks and immobilisationwas discontinued at 8 weeks. Physiotherapy wasinitiated to regain the strength and range of move-ments of the wrist. At 16 months follow-up (Fig. 4)there was no clinical or radiographic evidence ofcarpal instability, avascular necrosis or arthritis.There was 1208 of flexion/extension and 1408 ofpronation/supination at the wrist and he hadresumed his job as a delivery assistant in a store.

Discussion

Dislocation of the scaphoid is rare and very fewcase reports have been published.1—3 In 50% of thereported cases, the diagnosis was missed initially.2

A characteristic radiographic feature of scaphioddislocation is the palmar and radial displacementof the proximal pole of sacphoid out of the sca-phiod fossa of the radius.3 Good functional results

have been uniformly reported after both surgicaland non surgical management, provided that thecondition is recognised and treated early.2

Delayed diagnosis not only increases the likelihoodof open reduction for the dislocation but alsoaffects the final outcome because of stiffness ofthe wrist and fingers and arthritis of intercarpaland radiocarpal joints.4 Simple radiographs areusually sufficient to make a diagnosis, and delay

186 J. Arora, A. Pillai

in recognition is mainly due to lack of awareness ofthis rare injury.

The exact mechanism of scaphoid dislocation isnot known but it is generally believed that dorsi-flexion, ulnar deviation with or without rotationalforces are involved.2,3 It represents a spectrum ofinjuries with varying extent of ligamentousdamage.2,3 Radiographs can provide some indicationof the severity but wrist arthroscopy allows a moreaccurate assessment of individual ligaments and is auseful adjuvant modality in the management.3 Pre-operative AP view Xrays of the wrist (Fig. 1) shows‘Cortical ring sign’ indicating rotation of the sca-phoid bone and suggesting injury to the interosseousscapholunate ligament. The avulsed radial styloidfragment is still attached to the scaphoid and isequivalent to an injury to the radioscaphocapitateligament (which is always injured in scaphoid dis-locations). The scaphoid fossa (on the diststal radialarticular surface) is empty and the proximal pole ofscaphoid is displaced out, whereas lunate bone ispresent in its anatomical position in the lunate fossa.This case could be classified as complex dislocationaccording to the classification of Leung et al.2

because of the disruption of distal carpal row and adiastasis between capitate/hamate and middle/ringmetacarpals. We did not observe any radiological

changes suggestive of avascular necrosis of the sca-phoid. In fact only one case of established avascularnecrosis of the scaphoid has been reported in theliterature following this injury,3 in spite of total lossof blood supply expectedwith complete disruption ofall ligamentous attachments. It is proposed thatthere are intact intraosseous channels inside theintact scaphoid bone that allow rapid revasculariza-tion from surrounding soft tissues.2

Because scaphoid dislocation is missed fre-quently, we aim to increase the awareness of thisrare injury and emphasise that early diagnosis andtreatment contributes significantly to good prog-nosis.

References

1. Antuna SA, Antuna-Zapico JM. Open dislocation of carpalscaphoid: a case report. J Hand Surg 1997;22-A:86—8.

2. Leung YF, Wai YL, Kam WL, Ip PS. Solitary dislocation of thescaphoid-from case report to literature review. J Hand Surg1998;23-B:88—92.

3. Szabo RM, Newland CC, Johnson PG, et al. Spectrum of injuryand treatment options for isolated dislocation of the scaphoid.A report of three cases. J Bone Joint Surg 1995;77-A:608—15.

4. Takami H, Takahashi S, Ando M. Dislocation of carpal scaphoidassociated with median nerve compression. J Trauma 1992;33:921—4.