Radial-ulnar Deviation Motion Research Articles

The effect of coordinate system selection on wrist kinematics

Three-dimensional motion analysis of the hand and wrist is common in in-vitro and in-vivo biomechanical research. However, all studies rely on post testing analysis, where anatomical joint coordinate systems (JCS) are created to generate clinically relevant data to describe wrist motion. The purpose of this study was to present a comparison of four JCS that have been previously described in literature. Five cadaveric upper limbs were passively cycled through a flexion–extension and radial-ulnar deviation motion pathways using a wrist motion simulator. During testing, clinical wrist angle was measured using a goniometer. Following testing, wrist angle was calculated using four previously described methods of generating wrist coordinate systems, to facilitate their comparison. For flexion–extension wrist motion, only subtle difference between JCSs were detected. When comparing the performance of each JCS to the measured wrist angle during flexion–extension wrist motion, the RMSE for all three analyzed axes were all within 6.6°. For radial-ulnar deviation wrist motion, again only subtle difference between JCSs were detected. When comparing the performance of each JCS to the measured wrist angle during radial-ulnar deviation wrist motion, the RMSE for all three analyzed axes were all within 7.1°. The results of this coordinate system comparison do not favor one JCS generation method over another, as all were found to be similar and the small differences that were found are likely not clinically significant. We support using any of the analyzed coordinate system generation methods; however, a practical advantage of using certain methods is that the required digitized points to form the coordinate systems are palpable on the skin’s surface.

Differences in the Rotation Axes of the Scapholunate Joint During Flexion-Extension and Radial-Ulnar Deviation Motions

To determine the location of the rotation axis between the scaphoid and the lunate (SL-axis) during wrist flexion-extension (FE) and radial-ulnar deviation (RUD). An established and publicly available digital database of wrist bone anatomy and carpal kinematics of 30 healthy volunteers (15 males and 15 females) in up to 8 different positions was used to study the SL-axis. Using the combinations of positions from wrist FE and RUD, the helical axis of motion of the scaphoid relative to the lunate was calculated for each trial in an anatomical coordinate system embedded in the lunate. The differences in location and orientation between each individual axis and the average axis were used to quantify variation in axis orientation. Variation in the axis location was computed as the distance from the closest point on the rotation axis to the centroid of the lunate. The variation in axis orientation of the rotation axis for wrist FE and RUD were 84.3° and 83.5°, respectively. The mean distances of each rotation axis from the centroid of the lunate for FE and RUD were 5.7 ± 3.2 mm, and 5.0 ± 3.6 mm, respectively. Based on the evaluation of this dataset, we demonstrated that the rotation axis of the scaphoid relative to the lunate is highly variable across subjects and positions during both FE and RUD motions. The range of locations and variation in axis orientations in this data set of 30 wrists shows that there is very likely no single location for the SL-axis. Scapholunate interosseous ligament reconstruction methods focused on re-creating a standard SL-axis may not restore what is more likely to be a variable anatomical axis and normal kinematics of the scaphoid and lunate.

Cine MRI of the Triangular Fibrocartilage Complex during Radial-Ulnar Deviation.

Purpose Changes in the shape of the triangular fibrocartilage complex (TFCC) during radial-ulnar deviation were studied using "cine-mode" magnetic resonance imaging (MRI) in 10 right wrists of healthy volunteers, 5 wrists of TFCC tear, and 5 wrists of ulnar styloid nonunion. Subjects and Methods The wrist was fixed in a custom acrylic device, which only allows radial and ulnar deviation. Coronal MR images of nine radial-ulnar deviated positions (every 5 degree from 15 degrees radial deviation to 25 degrees ulnar deviation) were obtained in volunteers and patients. Cine-mode MRI was assembled and was output to MPEG video to observe. Results Cine MRI demonstrated the ulnar side of the TFCC was elongated by average 15 mm in 15 degrees of radial deviation and shortened by average 8 mm in 25 degrees of ulnar deviation in all normal TFCC subjects. Distal portion of the triangular fibrocartilage (TFC) was compressed during radial-ulnar deviation in 10 healthy volunteers and in 3 patients, but proximal portion of the TFC was stable throughout the motion. In contrast, the wavy deformities on the disc in ulnar deviation were observed in three patients with horizontal tear inside the TFCC. In nonunion of the ulnar styloid process, the fragment was snapped in maximum ulnar deviated position or elongation of the space between the styloid fragment and ulna was seen. Conclusion This study indicated normal and abnormal changes in the shape of the TFCC during radial-ulnar deviation motion on cine MRI. The abnormal dynamic changes of the TFCC may be seen in ulnar deviated position in patients, which are related to positive ulnocarpal stress test with the wrist forced ulnar deviated.

Principal components of wrist circumduction from electromagnetic surgical tracking.

An electromagnetic (EM) surgical tracking system was used for a functionally calibrated kinematic analysis of wrist motion. Circumduction motions were tested for differences in subject gender and for differences in the sense of the circumduction as clockwise or counter-clockwise motion. Twenty subjects were instrumented for EM tracking. Flexion-extension motion was used to identify the functional axis. Subjects performed unconstrained wrist circumduction in a clockwise and counter-clockwise sense. Data were decomposed into orthogonal flexion-extension motions and radial-ulnar deviation motions. PCA was used to concisely represent motions. Nonparametric Wilcoxon tests were used to distinguish the groups. Flexion-extension motions were projected onto a direction axis with a root-mean-square error of [Formula: see text]. Using the first three principal components, there was no statistically significant difference in gender (all [Formula: see text]). For motion sense, radial-ulnar deviation distinguished the sense of circumduction in the first principal component ([Formula: see text]) and in the third principal component ([Formula: see text]); flexion-extension distinguished the sense in the second principal component ([Formula: see text]). The clockwise sense of circumduction could be distinguished by a multifactorial combination of components; there were no gender differences in this small population. These data constitute a baseline for normal wrist circumduction. The multifactorial PCA findings suggest that a higher-dimensional method, such as manifold analysis, may be a more concise way of representing circumduction in human joints.

The effect of lunate position on range of motion after a four-corner arthrodesis: A biomechanical simulation study

A four-corner arthrodesis of the wrist is a salvage procedure for the treatment of specific wrist disorders, to achieve a movable, stable and pain free joint. However, a partial arthrodesis limits the postoperative range of motion (ROM). The goal of this study is to understand the mechanism of the reduction of the ROM and to evaluate the effect of the orientation of the lunate in the four-corner arthrodesis on the range of motion by using a biomechanical model, containing articular contacts and ligaments. Multi-body models of a normal wrist and a four-corner arthrodesis wrist with different orientation of the lunate were used for simulations of flexion–extension motion (FEM) and radial–ulnar deviation motion (RUD). The ROM of the postoperative wrist was reduced from 145° to 82° of the total arc of FEM and from 73° to 41.5° of the total arc of RUD. The model simulations show that the range of motion reduction is caused by overtension of the extrinsic wrist ligaments. Different positioning of the lunate changes the balance between the contact forces and ligament forces in the wrist. This explains the effect on the postoperative range of motion. The 20° flexed lunate did not give any gain in the extension motion of the wrist, caused joint luxation in flexion and limitation in RUD. The 30° extended lunate caused overtension of the extrinsic ligaments attached to the lunate. The ROM in this case is dramatically reduced. The model simulations suggest that the neutral position of the lunate seems to be most favorable for mobility of the wrist after a four-corner arthrodesis procedure.

Wrist joint motion simulator

A computer controlled wrist joint motion simulator has been developed that actively moves forearms from cadavers through cyclic planar flexion-extension motions, planar radial-ulnar deviation motions, and combined motions such as circumduction. Hybrid position-force feedback control algorithms are used to determine the wrist flexor and extensor tendon forces necessary to achieve the desired motions. The simulator was used in a series of 12 fresh cadaver forearms to produce both flexion-extension and radial-ulnar deviation motions and was found to cause repeatable, physiological movements. In these experiments, the extensor tendon forces were greater than those of the flexors, typically by a factor of two.

The SLAC wrist: Scapholunate advanced collapse pattern of degenerative arthritis

Four thousand wrist x-ray films were reviewed to establish the pattern of sequential changes in degenerative arthritis of the wrist. After eliminating all other arthritides, we studied 210 cases of degenerative arthritis. The most common pattern (57%) was arthritis between the scaphoid, lunate, and radius; 27% of cases occurred between the scaphoid, trapezium, and trapezoid; a combination of these two patterns occurred in 15%. Twenty operations were performed on 19 patients with the scapholunate advanced collapse pattern. Eighteen of 19 patients had less pain postoperatively and none required pain medication. Flexion-extension and radial-ulnar deviation motions showed considerable improvement after the operation.