Introduction

Amongst various differential diagnoses, cystic lumps on the dorsum of the wrist are clinically quite suggestive of a ganglion. This is at times misleading and may camouflage the presence of an underlying loose body, which unless dealt with will not alleviate the symptoms in the patient. The case report helps illustrates this.

Case report

A 22 year old man, presented with a swelling on the dorsum of the wrist in his right dominant hand, for about a year. The swelling was intermittent in nature and being associated with intermittent pain, interfered with the patient's work.. There was no history of recent trauma nor any history suggestive of synovial or arthritic pathology. The patient had however sustained a fracture of the distal radius about ten years ago which was managed by immobilisation in a splint. The patient had been referred to us by his general practitioner with a working diagnosis of a ganglion.

Clinical examination revealed a well defined 10x10 mm subcutaneous lump over the dorsum of the wrist (figure 1), which was tender, firm in consistency, fluctuant and transilluminable. Full range of movements was present at the wrist joint, with some pain but no associated clicking or locking.

Figure 1

Figure 1: Tender, firm, immobile, transilluminable, 10x10 mm lump over the dorsum of the wrist.

Plain radiographs showed a loose body of about 3x9 mm in the radio-carpal joint (figure 2).

Figure 2

Figure 2: Plain radiographs showing a loose body of about 3x9 mm in the radio-carpal joint.

A miniarthrotomy was performed and the loose body removed from the joint. Post operative recovery was uneventful. The surgery helped relieve the patient's symptoms and the patient has remained pain free on follow up at two years.

Discussion

Dorsal wrist ganglions are quite common in our day to day practice. On the other hand, loose bodies in the wrist are quite rare. On account of this they are generally not suspected in a patient presenting with a swelling on the dorsum of the hand which clinically simulates a ganglion in appearance. Loose bodies tend to involve the piso-triquetral joint or radio-carpal joint. Loose bodies in the piso-triquetral joint can originate in the joint itself or can migrate from the radio-carpal joint.₁ They can be a result of trauma in the form of acute trauma₂ or chronic repetitive trauma.₁ Arthropathies such as pseudo gout, gout, osteoarthritis, chondrocalcinosis, apatite calcifications, rheumatoid arthritis₁,₃ can result in the formation of loose bodies. They can also form secondary to Synovial osteochondromatosis, Osteochondrirtis dissecans.₃

Patients usually present with wrist pain, locking, crepitus on motion. or a snapping sensation.₁,₄,₅,₆ Inspection does not show any signs of a loose body, however in our case there was a lump at the affected site which simulated a ganglion in appearance. It is important to be aware of loose bodies presenting as a lump as in the initial stages, plain radiographs are not diagnostic.₁,₅

Conservative management with analgesics, steroid injections have been shown to be of little use.₁ Surgical removal of loose bodies is effective and can be achieved either on arthroscopy or by arthrotomy.₁,₄Arthrotomy is advised in cases of chondrocalcinosis, where multiple loose bodies occur.₇

In conclusion, it is important to be aware of the fact that loose bodies in the wrist can present as a dorsal lump simulating the appearance of a ganglion and conservative management of these will not relieve the patient's symptoms These cases will need an operative intervention to remove the loose body.

Correspondence to

Mr A L Mahajan Department of Plastic and Reconstructive Surgery Derriford Hospital Plymouth PL 6 8DH UK Email: almahajan@yahoo.com Phone: +44 7725 355903