pisiformtriquetral

Pisiform-triquetral refers to the anatomical relationship between the pisiform and triquetral bones of the wrist, particularly the pisiform-triquetral joint. The pisiform is a small sesamoid bone embedded in the tendon of the flexor carpi ulnaris, positioned on the palmar surface of the triquetrum, one of the proximal carpal bones. The joint between these two elements is a minor, planar articulation that allows limited gliding as the wrist moves.

Anatomy and function: The pisiform-triquetral joint is supported by ligaments that stabilize the palmar and dorsal aspects of the wrist, including associations with the surrounding radiocarpal ligaments and a pisiform-triquetral ligament complex. The pisiform itself functions as a pulley for the flexor carpi ulnaris tendon, increasing the tendon’s leverage and contributing to wrist flexion strength, while the pisiform-triquetral articulation adds slight mobility within the proximal carpal row.

Development and variation: In most individuals, the pisiform and triquetrum are separate bones. A rare anatomical variant is a pisiform-triquetral coalition, where a bony, cartilaginous, or fibrous connection fuses the two elements. Such coalitions are uncommon compared with other carpal coalitions and are often incidental findings on imaging; they may be asymptomatic or associated with medial-wrist pain in some cases.

Clinical significance and imaging: When symptomatic, evaluation involves plain radiographs and may include CT or MRI to characterize the coalition and exclude other pathology. Treatment is usually conservative, focusing on pain management and wrist function, unless coalition-related symptoms persist or limit activity.