Hunchback” carpus is defined by a hard swelling at the base of the 2nd and 3rd metacarpals. This swelling may be acquired, more common in women than men, on the dominant side and occurring around the age of forty, an arthritic degeneration whose “parrot’s beak” is palpable under the skin. Certain exposed professions or sports (boxing, etc.) can lead to this pathology earlier in life.
This lesion can sometimes be congenital, due to ossification of a local accessory nucleus, which becomes painful -for unknown reasons-.
CLINICAL SIGNS:
The reason for consultation is either “aesthetic”; it’s the appearance of the lump that bothers the patient. This swelling may also be painful due to the mechanical conflict it causes with the neighbouring extensors. An arthro-synovial cyst may also be associated.
FURTHER INVESTIGATIONS
A standard X-ray of the face and, above all, of the strict profile – or comparative X-ray – makes the diagnosis.
MRI may be useful in cases of associated extensor tenosynovitis, or in cases of doubt as to the differential diagnosis with dorsal wrist arthrosynovial cyst.
Traitement:
Treatment depends on the severity of the disorder and, in particular, on the pain symptomatology:
- recent and not very painful forms, whose discomfort is essentially aesthetic, are treated by wearing a splint for 3 weeks, combined with corticosteroid infiltration.
- In cases of intense and/or persistent pain, treatment is surgical. The incision is horizontal, and consists in subperiosteal resection of the hump by means of a wedge-shaped osteotomy, until healthy carpo-metacarpal articular cartilage is restored. The arthro-synovial cyst is removed at the same time; extensor synovectomy may be necessary. The wrist is then immobilized for 15 days.
