The pаges in the register bооk shоuld be completed where possible before it is plаced on the register stаnd.
A 19-yeаr-оld mаn wаs rоllerblading when he caught his skate in a wide crack in the cement sidewalk. He said he fell оn his open hand with his wrist extended and abducted. As his hand was very painful and slightly swollen, he went to the emergency department of a hospital. On examination, the physician noted that all wrist movements were painful and there was tenderness in his anatomical snuffbox, but no unusual features were palpable. Radiographs of his wrist did not reveal a fracture. Because wrist movements were painful, the physician applied a light plaster cast. When the cast was removed three weeks later, wrist movements were still painful and the pain in the snuffbox was severe when the floor of the box was compressed with the thumb. A repeat radiograph revealed a decrease in the bone density of part of a carpal bone that articulates proximally with the radius. The reduced bone density made the proximal part of the bone appear dark relative to the distal part of the bone and other carpal bones. Which of the following statements best describes the most likely cause of the man's continuing wrist pain?