Radial styloidectomy: a biomechanical study on stability of the wrist joint.
We investigated the influence of radial styloidectomy on carpal alignment and examined translation of the wrist after sequentially increased styloidectomy of 8 cadaver wrists. The radial aspect of the scaphoid fossa of the distal radius was cut obliquely at 3, 6, and 10 mm from the radial styloid guided by real-time fluoroscopy. Radiographic analysis of the changes of carpal alignment was performed with the wrist in neutral position. Force-displacement curves from the neutral to the radioulnar and palmar-dorsal directions were obtained using a multi-axis testing machine. Results demonstrated no significant malalignment of the carpal bones after radial styloidectomy. Significantly increased radial translation (>40% reduction in stiffness), however, was observed due to the loss of radial articular contact after 6- and 10-mm radial styloidectomies. Significant ulnar and palmar carpal displacement also was noted after 6- and 10-mm radial styloidectomies, with 6 specimens demonstrating moderate ulnar and palmar translation and 2 demonstrating notable increased palmar and ulnar translations. We conclude that there is a definite risk of increased carpal instability with radial styloidectomy procedures. A styloidectomy of no more than 3 to 4 mm is recommended.
Nakamura
T
T
Orthopedic Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic/Mayo Foundation, 200 First St. SW, Rochester, MN 55905, USA..
Cooney
W P
WP
Lui
W H
WH
Haugstvedt
J R
JR
Zhao
K D
KD
Berglund
L
L
An
K N
KN
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002348:Carpal Bones / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology; D014955:Wrist Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*