ANATOMIC STUDY OF THE PISOTRIQUETRAL JOINT - LIGAMENT ANATOMY AND CARTILAGENOUS CHANGE

Eighty embalmed cadaver wrists (40 right and 40 left, 55 male and 25 f emale, aged 36 to 93 years [average age, 72.5 years]) were dissected t o assess the anatomy of the pisotriquetral joint and the location of d egenerative changes. The patterns of degenerative changes were classif ied into five types: type 1, central (8.8%); type 2, peripheral (38.8% ); type 3, fan-shaped (13.8%); type 4, mixed (combination of greater t han or equal to 1 of types 1, 2, and/or 3; 10.0%); and type 5, total ( 12.5%). There was no cartilagenous change in 16.2% of the pisoform and 13.7% of the triquetrum. Degenerative changes (exposed subchondral bo ne and chondromalacia) on the articular surface of the pisiform were p resent in 83.3% of the wrists and on the triquetrum in 86.3% of the wr ists. Degenerative changes were most commonly of the type 2 pattern (p eripheral), with change located most commonly in the distal, distal-ra dial, and radial aspects of the pisiform and triquetrum. The ligamento us anatomy was categorized into 3 different types: type A, pisohamate and pisometacarpal ligaments inserted on the palmar distal aspect of t he pisiform (52.5%); type B, pisohamate ligament inserted on the radia l side of the pisiform and pisometacarpal ligament inserted on the pal mar side of the pisiform (41.3%); and type C, type B anatomy with an a dditional ligamentous slip between the pisometacarpal ligament and the distal aspect of the hook of the hamate (6.2%). (J Hand Surg 1998;23A :600-606, Copyright (C) 1998 by the American Society for Surgery of th e Hand.)