Digital templating in total hip arthroplasty with the Mayo stem.
METHODS
In 40 patients undergoing total hip arthroplasty with the Mayo femoral stem we studied how preoperative digital templating corresponded to the actual intraoperative choice of implant size, position, offset and restoration of leg length.


RESULTS
The preoperatively planned sizes of the components showed a high rate of coincidence with the sizes used intraoperatively [Intraclass Correlation Coefficient (ICC) 0.661-0.810]. However, the agreements in offset and CCD correction were poor (ICC 0.476, 0.253). This could be statistically attributed to the change in the distance from the medial margin of the stem to the medial margin of the medial femoral cortex and the height of osteotomy. The agreement in leg length correction was moderate (ICC 0.583), which was attributed to the change in the hip rotation center and the height of osteotomy.


CONCLUSIONS
Careful preoperative planning was useful for accurate size choice of the Mayo prosthesis. Factors such as the height of osteotomy and the distance from the medial margin of the stem to the medial margin of the medial femoral cortex in relation to the position of the Mayo stem should be taken into account in order to restore ideal offset and leg length.
Wedemeyer
Christian
C
Department of Orthopaedics, University of Duisburg-Essen, Essen, Germany. christian.wedemeyer@uni-duisburg-essen.de
Quitmann
Henning
H
Xu
Jie
J
Heep
Hansjoerg
H
von Knoch
Marius
M
Saxler
Guido
G
D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005271:Femur Head Necrosis / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011300:Preoperative Care; D025321:Surgery, Computer-Assisted / Q000379:methods*