Kinematics and laxity of the Souter-Strathclyde total elbow prosthesis.
The motion pattern and laxity of 8 cadaveric elbows were recorded with a 3-dimensional electromagnetic tracking device before and after the Souter-Strathclyde total elbow prosthesis was implanted. The Souter-Strathclyde prosthesis replicates the valgus-varus motion pattern of the intact elbow but causes a significant internal rotation of the ulnar shaft of 8.9 degrees +/- 4.1 degrees (P < .0005) at 110 degrees of elbow flexion. One of the reasons for this unphysiological motion pattern is positioning of the humeral component in a mean of 5.4 degrees +/- 6.4 degrees of external rotation compared with the intact elbow (P = .05). This positioning is related to the design of this device. The Souter-Strathclyde elbow prosthesis has a mean maximum valgus-varus laxity of 6.5 degrees +/- 1.5 degrees compared with 4.3 degrees +/- 2.3 degrees for the intact elbow (P = .004). This implant is more constrained than previously tested devices, which may explain its relatively higher loosening rate.
Schneeberger
A G
AG
Orthopedic Biomechanics Laboratory, Mayo Clinic and Foundation, Rochester, Minn. 55905, USA.
King
G J
GJ
Song
S W
SW
O'Driscoll
S W
SW
Morrey
B F
BF
An
K N
KN
D000328:Adult; D001696:Biomechanical Phenomena; D002102:Cadaver; D004551:Elbow Joint / Q000601:surgery*; D006801:Humans; D007595:Joint Prosthesis; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity