THE VALUE OF ADDITIONAL CARPAL BOX RADIOGRAPHS IN SUSPECTED SCAPHOID FRACTURE

RATIONALE AND OBJECTIVES. Carpal Box (CB) radiographs, transverse and longitudinal, produce elongated and magnified views of the carpus, The se radiographs can be used after carpal injury, in addition to convent ional scaphoid x-rays, In this study, the use of CB radiographs was ev aluated in patients with possible scaphoid fracture, METHODS. Seventy- one consecutive patients who presented at the First Aid department fro m May 1994 to May 1995 were included, All patients were examined for s caphoid fracture after a fall on the out-stretched hand, If a scaphoid fracture was seen on the scaphoid x-rays, patients were immobilized, If the x-rays remained negative or dubious for fracture, additional tr ansverse and longitudinal CB radiographs were obtained, If CB radiogra phs remained negative or inconclusive, patients were referred for thre e-phase bone scintigraphy, The results of independent and masked judgm ent by three different observers were used for an inter- and intraobse rver analysis, RESULTS. Twenty of 71 patients initially showed a scaph oid fracture on the conventional scaphoid x-rays, 41 were negative, an d 10 inconclusive. All 41 negative patients remained negative on CB ra diograph; however, the bone scintigraphy was positive for scaphoid fra cture in 11 patients and in 9 patients a hot spot elsewhere in the car pus was found, Of the 10 patients with inconclusive x-rays, 2 showed a clear fracture of the scaphoid on CB radiograph, 5 were negative, and 3 remained inconclusive, The agreement between observers, calculated in kappa values, was highest in CB radiographs, CONCLUSIONS. In the di agnosis of scaphoid fracture, Carpal Box radiography is of limited val ue in patients with clinically suspected scaphoid fracture, In two of 10 patients with initial dubious scaphoid x-ray, bone scintigraphy can be avoided, Furthermore, the reliability of the interpretation of the radiographs is increased by additional Carpal Box radiography.