Normal ultrasound anatomy of the triangular fibrocartilage of the wrist: a study on cadavers and on healthy subjects.

PURPOSE To report the normal sonographic anatomy of the triangular fibrocartilage (TFC) of the wrist in cadavers and volunteers. METHOD Five hands from cadavers were examined sonographically before and after wrist dissection, during which the TFC was marked with surgical wires. Twenty volunteers without wrist limitation or pain, and without any history of wrist disease or inflammatory arthritis (mean age, 26 years (range,19-45 years) were also examined. RESULTS Sonograms showed that the meniscus and the TFC were clearly separated. The meniscus appeared as a triangular structure that was homogeneous and slightly hyperechoic. Compared with the meniscus, the TFC appeared hypoechoic. The same patterns were observed for cadavers and volunteers. In 3 volunteers (15%), the TFC was not visualized. CONCLUSIONS Using high-resolution ultrasound systems, the TFC can be separated from meniscus. However, visualization of the TFC remains limited due to its deep location and the presence of acoustic shadowing from bony structures.