Every severe sprain or injury in the region of the carpal navicular should be considered a fracture until proved otherwise.
The results in these cases substantiate good orthopaedic teaching that, if a fracture of the carpal navicular is accurately reduced and adequately immobilized for a sufficient time, solid bony union may be expected.
Failure to diagnose, to reduce, and to immobilize these fractures properly is directly responsible for delayed union or non-union.
In delayed treatment, the presence of vacuolation or cystic change is not considered discouraging. When the fracture has been properly immobilized, the healing which takes place in the cystic area will include the fracture line.
If the proximal fragment is viable, sclerosis at the site of fracture is no contra-indication to prolonged immobilization. As a rule, after two or three months of uninterrupted immobilizations, decalcification of the sclerosis will be observed, signs of union will follow, and ultimately solid bony union will take place.
In adequately immobilized fresh fractures, the development of avascular sclerosis in the proximal fragment is no contra-indication to continued non-operative treatment. In the majority of cases, the fracture will unite and the proximal fragment will be revascularized. The wrist must be protected until revascularization is complete.
Rarely will normal function of the wrist be obtained following excision. Bone-grafting or drilling will not, except in an occasional case, offer any better prospect of union, nor will they, as a rule, reduce the average period of disability.
In the occasional fracture with excessive displacement of the proximal third, early excision of the proximal fragment is recommended, unless accurate reduction can be obtained by manipulation.
The type of plaster cast described ensures adequate immobilization of the navicular and allows the patient excellent use of the hand.
Immobilization may be prolonged for a year or more if daily exercise and activity of the fingers are systematically practised.