Kinematics of the wrist

Abstract

We enrolled 34 normal volunteers to test the hypothesis that there were two types of movement of the wrist. On lateral radiographs two distinct patterns of movement emerged. Some volunteers showed extensive rotation of the lunate with a mean range of dorsiflexion of 65°, while others had a mean range of 50°. The extensive rotators were associated with a greater excursion of the centre of articulation of the wrist. It is suggested that dynamic external fixation of a fracture of the distal radius carries with it the risk of stretching the ligaments or causing volar displacement at the site of the fracture. Movement of the wrist during flexion and extension takes place at the radiolunate and lunate-capitate joints. Because of the complexity of its kinematics, many studies describe multiple readings on a few specimens or volunteers, 1,2 although a few have reported more extensive series of subjects. 3,4 There is debate as to whether the wrist functions as a row of carpal bones or as a column. Recently, Craigen and Stanley 3 suggested that there may be two types of wrist, one functioning as a row and one as a column. Their comparative study was based on measurements of lengthening and shortening of the scaphoid as seen on the posteroanterior view of the wrist. Our study is based on the senior author's (BDF) observation that, when the wrist is viewed from the lateral side during dorsal and palmar flexion, the lunate seems to rotate more in some wrists than others. If this observation is true there are implications for dynamic external fixation of the wrist. Our study was designed to investigate whether there are two types of wrist movement as seen on the lateral view, and to relate this observation to the study by Craigen and Stanley 3 of posteroanterior carpal kinematics. Subjects and MethodsRadiographs were taken of the non-dominant wrists of 34 subjects in five standard projections with the shoulder abducted to 90° and the elbow flexed to 90°. Two posteroanterior views were taken with the wrist in full active radial and ulnar deviation and three lateral views with the wrist in full active dorsiflexion, neutral and in full active palmar flexion.On the posteroanterior radiographs, measurement of the length of the scaphoid and the degree of scaphoid translation were made in both radial and ulnar deviation and the CR index and translation ratio calculated as described by Craigen and Stanley.3 The CR index is the length of the scaphoid in radial deviation divided by its length in ulnar deviation. We measured the scapholunate gap in ulnar deviation on the radiographs to exclude occult scapholunate instability and the angle of volar inclination of the articular surface of the distal radius on the lateral films. The angles of dorsal and palmar flexion of the lunate and capitate in relation to the radius were also determined. The range of flexion and extension of the capitate within the lunate fossa was calculated from these figures. The centre of the capitate was located and the distance which it moved during dorsal and pa...

Accessory Movement of the Lunate during Active Flexion and Extension Motion of the Wrist

“…Taking this result as a preliminary result, we would like to study many subjects, to investigate the reliability of the variance value and also its correlation with joint dysfunction. It is worth noting in this connection that Ferris et al 15) have shown that the center of the lunate moves slightly dorsally when the wrist is fully dorsiflexed. Their result differs from our result and also from that of Jackson et al 4) .…”

A principal component analysis-based framework for statistical modeling of bone displacement during wrist maneuvers

“…Considerable progress has been made in the acquisition of in vivo images during wrist motion. Published methods have used 2D static radiographs (Craigen & Stanley, 1995;Ferris et al, 2000), 3D static computed tomagraphy (CT) (Crisco et al, 1999;Halilaj et al, 2014;Wolfe et al, 2000), and 3D static MRI (Fischer et al, 2011;Goto et al, 2005;Pillai et al, 2007). However, more recently, 4D (3D + time) imaging has become available via dynamic CT (Foumani et al, 2009;Garcia-Elias et al, 2014;Jais & Tay, 2017) and dynamic MRI (Boutin et al, 2013;Shaw et al, 2017).…”

Performance evaluation of surgical techniques for treatment of scapholunate instability in a type II wrist

“…The categorisation is seldom mentioned in the literature, and only recently have some authors discussed the incidence, variation, associated pathologies, and the clinical importance of the extra facet, including some studies that relate lunate morphology to carpal mechanics. Statistically, there is no correlation between lunate type and gender, age, hand dominance, or occupation …”

“…In row theory, the carpal bones are divided into two rows of adjacent bones. The proximal row consists of the scaphoid, the lunate, the triquetrum, and the pisiform; the distal row composes of the hamate, capitate, trapezium, and trapezoid (see Figure A) . During clench fist ulnar deviation (volar view), the proximal row rotates and slides over the concave surface of the radius; meanwhile, the distal row rotates in the same direction sliding over the proximal row allowing the motion (Figure ).…”

“…In column theory, the carpal bones are distributed into three columns: The lateral column consists of the scaphoid; the central column consists of lunate, capitate, hamate, trapezium, and trapezoid; and the medial column consists of the triquetrum and pisiform (Figure C). Column theory suggests that during ulnar deviation (volar view), the central column rotates clockwise (in the ulnar direction); simultaneously, the medial column slides over the hamate to the dorsal side making space for the moving bones; meanwhile, the scaphoid tilts towards the vertical by the pulling of the ligament that joins it with trapezium and trapezoid (Figure D). To date, validation of these theories has only been performed using plane X‐ray and fluoroscopic studies …”