The late consequences of scaphoid fractures.

Fractures which unite Nearly 90% of scaphoid fractures unite with conservative treatment2,3 and the overall clinical impression is that patients continue to progress well and remain free of symptoms. However, they are rarely followed up after the fracture has united. Dias, Brenkel and Finlay4 followed up patients for between 1.7 and 2.6 years and found that 20% had some pain and 19% tenderness, but grip strength and wrist movement were nearly normal. They suggested that the persistent symptoms could reflect damage to the articular cartilage at the time of the injury. Secondary osteoarthritis may develop after the fracture has united. Lindström and Nyström5 showed in 1990 that after seven years or more osteoarthritis occurred in 5% of wrists in which a fracture of the scaphoid had healed normally and suggested that it would probably progress. In 2001 Saéden et al6 described a study of acute fractures, some treated in a cast and some by a Herbert screw. The patients were reviewed after 10 to 12 years, when CT scans and plain radiographs were carried out on both wrists. Of the 16 patients treated conservatively, seven had osteoarthritis in the radiocarpal joint and seven in the scaphotrapezial joint. The higher incidence of osteoarthritis reported in this series was probably because it was revealed by the CT scans. Why should osteoarthritis develop after a fracture has united? It may be because of damage to the articular cartilage sustained at the time of the fracture or, as Lindström and Nyström5 suggest, to some degree of malunion. It would be likely to occur if the fracture had healed with a step in the articular surface. Such displacement is seldom seen on ordinary scaphoid radiographs. It cannot be detected reliably on such films and may only be demonstrable by MRI or CT scans.7