Fresh Cadaver Wrists Research Articles

Histologic anatomy of the triangular fibrocartilage

The collagen arrangement of the triangular fibrocartilage complex was studied in 20 fresh cadaver wrists by means of standard and polarized light microscopy and scanning electron microscopy. The collagen fibres in the articular disk are arranged in undulating sheets oriented at oblique angles to each other. The fibers of the radioulnar ligaments are oriented longitudinally from the radial origin to the ulnar insertion. The origin of the articular disk from the radius is characterized by thick fibers 1 to 2 mm in length radiating from the radius into the articular disk. Five specimens were also injected with india ink. The radioulnar ligaments and the peripheral 15% to 20% of the articular disk are well vascularized, whereas the central 80% of the articular disk is avascular.

Intraarticular fractures of the distal radius: A cadaveric study to determine if ligamentotaxis restores radiopalmar tilt

Nineteen fresh cadaver wrists were divested of all dorsal and palmar tissues to the wrist capsule and extrinic and intrinsic ligaments. A Frykman VII type fracture was established across the radiocarpal and radioulnar joints. The dorsal and palmar wrist ligaments were left intact. The forearms were stabilized in an arm board and an external fixation device and traction applied through a Kirschner wire at the base of the third metacarpal. Three positions of wrist flexion; neutral, 15, and 30 degrees, with 10 and 20 pounds of traction were used to attempt to reestablish radiopalmar tilt. Only when the entire palmar ligamentous structures were transected at the radius was radiopalmar tilt reestablished. Ligamentotaxis alone is not a reliable method to reestablish radiopalmar tilt in intraarticular distal radius fractures.

Wrist kinematics after limited intercarpal arthrodesis

Two limited intercarpal fusions, scapho-trapezial-trapezoidal and scapho-capitate, were simulated in six fresh human cadaver wrists by means of two Herbert screws. By use of a biplanar radiographic measurement system, the relative kinematic behavior of selected carpal bones, before and after the simulated limited fusions could be analyzed. Both scapho-trapezial-trapezoidal and scapho-capitate fusions produced a similar reduction in global range of motion and comparable effects on the relative intracarpal motion. In both fusions, a significant reduction in relative motion at the lunocapitate joint was recorded. The scaphoid, being fused to the distal carpal row, was shown to lose its role in the adaptative mechanism that allows preservation of articular congruency to the always changing space between the distal carpal row and the radius. After both types of fusion, increased sliding motion of the lunate on the radius was found. These kinematic changes are likely to enhance shear stresses on the lunate and tension on the surrounding ligaments, potentially diminishing long-term functional results.

An anatomic guide for arthroscopic visualization of the wrist capsular ligaments

Wrist arthroscopy allows examination of the palmar capsular wrist ligaments without extensive exposure. Arthroscopic examination of the wrist requires an accurate knowledge of the ligamentous anatomy as seen from inside the joint. In this study 13 fresh cadaver wrists were examined from the inside out to provide a visual guide for ligament identification during arthroscopy. The major palmar capsular ligaments seen from the inside of the wrist at the radiocarpal joint include the radioscaphoid, radioscaphocapitate, radiolunate, radioscapholunate, ulnolunate, ulnotriquetral ligaments, and the ulnar capsule. At the midcarpal joint, the scaphocapitate, radioscaphocapitate, triquetrocapitate, and triquetrohamate ligaments are identified palmarly. Dorsally, constant capsular structures at the radiocarpal joint are the radiolunate and radioulnotriquetral ligaments along with a prominent synovial fold.

An in vitro analysis of wrist motion: The effect of limited intercarpal arthrodesis and the contributions of the radiocarpal and midcarpal joints

Radiocarpal and intercarpal arthrodeses were simulated in 12 fresh cadaver wrists by means of external fixation. Range-of-motion measurements were made before and after simulated arthrodesis and used to calculate the contribution of the midcarpal and radiocarpal joints to wrist motion, as well as the residual wrist motion after limited intercarpal arthrodeses. Relative contributions to wrist motion were as follows: wrist flexion: radiocarpal (RC) joint 63%, midcarpal (MC) joint 36%; wrist extension: RC joint 53%, MC joint 46%. The wrist motion remaining after simulated arthrodeses was as follows: capitate-hamate: flexion (Flx) 98%, extension (Ext) 92%, ulnar deviation (UD) 96%, radial deviation (RD) 90%; scaphoid-lunate: Flx 97%, Ext 91%, UD 90%, RD 91%; scaphoid-trapezium-trapezoid: Flx 86%, Ext 88%, UD 67%, RD 69%; scaphoid-lunate-triquetrum: Flx 91%, Ext 82%, UD 86%, RD 70%; capitate-lunate: Flx 70%, Ext 59%, UD 89%, RD 79%; capitate-hamate-triquetrum: Flx 88%, Ext 79%, UD 88%, RD 81%; hamate-triquetrum: Flx 90%, Ext 85%, UD 89%, RD 94%; scaphoid-trapezium-trapezoid-capitate: Flx 85%, Ext 77%, UD 64%, RD 57%.

Arthrotomography of the Wrist

Twenty-one fresh cadaver wrists were studied by arthrography and arthrotomography. Arthrography was unreliable in accurately delineating the palmar radiocarpal ligaments. However, lateral arthrotomograms predictively and precisely outlined the radiolucent radiocapitate and radiotriquetral ligaments. The radial and more distant radiolucent area was the radiocapitate ligament, and the ulnar and more proximal area was the radiotriquetral ligament. A constant radiopaque invagination between the outlines of contrast material demonstrated the sulcus anatomically separating these two ligaments. When the ligaments were transected contrast material entered the substance of the ligaments, rendering them radiopaque and, thus, visible on the radiographs. The authors believe that arthrotomography may be a useful clinical tool in the evaluation of post-traumatic injuries to the palmar radiocarpal ligaments of the wrist.

Arthrotomography of the Wrist

Eighteen fresh cadaver wrists were radiographically studied using both arthrography and arthrotomography, to evaluate the results of the two techniques. With arthrography, communications between the distal radioulnar and radiocarpal joints were discovered in eight of the 18 wrists (44%). Although defects in the triangular fibrocartilage complex (TFCC) could be inferred from the arthrograms, the locations and dimensions of the defects could not be assessed satisfactorily. Using arthrotomography, three distinct patterns of TFCC defects were observed radiographically, which correlated with subsequent anatomic dissections of the cadaver specimens. Type I defects, located near the radial margin of the TFCC, are long, narrow posteroanterior fissures with thick regular borders that readily appose. Type II defects, located more centrally in the TFCC, are wide defects with thin irregular margins. Type III defects represent a communication between the prestyloid recess and the distal radioulnar joint. Arthrotomography of the wrist accurately delineates TFCC defects in cadaveric specimens and may become a valuable clinical radiographic procedure.

Kinematics of the wrist. I. An experimental study of radial-ulnar deviation and flexion-extension.

The kinematics of the wrist during radial-ulnar deviation and flexion-extension were studied in several ways. In six fresh cadaver wrists, the forearm was fixed in full pronation, each motion was constrained to one plane, and two metal markers were placed in each of the finger metacarpals, as well as in the radius and all of the carpal bones except the pisiform and greater multangular. Radial ulnar and flexion-extension movements in these wrists were studied roentgenographically. In the wrists of six normal volunteers, a similar roentgenographic analysis was carried out and the trajectories of wrist motions also were studied using light-emitting diodes. Finally, roentgenographic measurements were made on 100 wrists of normal subjects. From these studies, it was concluded that: (1) during each of these motions, rotation occurs about a fixed axis located within the head of the capitate, and the location of each axis is not changed by the position of the hand in either plane; (2) the distance from the base of the third metacarpal to the distal articular surface of the radius (the carpal height), measured along the proximally projected axis of the third metacarpal on posteroanterior roentgenograms, is constant throughout radial-ulnar deviation of the normal wrist and can be used as a measure of carpal collapse; and (3) the perpendicular distance of the fixed axis of rotation for radial-ulnar deviation from the distally projected longitudinal axis of the ulna can be used as a quantitative measurement of the amount of translation of the carpus in pathological conditions.