[Determination of the axis after totalendoprosthesis of the knee: functional X-ray photography as golden standard].
OBJECTIVE
To examine the question of which X-ray photography technique should be given preference after implantation of total endoprosthesis of the knee.


METHODS
20 patients (age 74.1; 12 men, 8 women) with total endoprosthesis of the knee (Type Sigma, PFC, Johnson and Johnson) because of primary athrosis. Postoperatively X-ray photographs of the whole leg in standing and 40 x 20 a. p. in a flat position were taken. The angles of the axis were determined and the information analysed.


RESULTS
By means of X-ray photography of the whole leg we obtained the following angles: caput-collum-diaphyse 125 +/- 4.3 degrees, femur/basis of the knee 83.2 +/- 2.6 degrees, mechanical femur axis/basis of the knee 89.3 +/- 1.8 degrees, tibia/basis of the talus 89.2 +/- 2.2 degrees. With the 40 x 20 a. p. X-ray photographs we determined the following angles: femur/basis of the knee 82.3 +/- 3.1 degrees, basis of knee/tibia 92.2 +/- 3,6 degrees. Correlating the angles of femur/basis of the knee and basis of the knee/tibia were relations of 0.42 (p < 0.05) and 0.27 (p < 0.05).


CONCLUSIONS
For gaining information about the axis of the leg under functional conditions, one should give preference to X-ray photography of the whole leg.
Langenbach
M R
MR
Abteilung für Viszeral- und Allgemeinchirurgie der Universität Witten-Herdecke, Klinikum Barmen, Germany. MRLangenbach@aol.com
Dohle
J
J
Zirngibl
H
H
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D019985:Benchmarking; D017760:Bone Malalignment / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007866:Leg / Q000000981:diagnostic imaging*; D008297:Male; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011474:Prosthesis Design; D011859:Radiography