[Significance of sagittal stability in knee prosthesis implantation--an analysis of 76 cases with unconstrained joint surface replacement].
OBJECTIVE
How does the sagittal stability influence the outcome in unconstrained knee arthroplasty?


METHODS
In order to clarify this aspect, 76 arthroplasties (10 male, 66 female, 39x gonarthrosis, 37x rheumatoid arthritis) in 61 patients with unconstrained primary knee arthroplasty were examined with a mean follow-up of 4 years. The determined values were the HSS-Score, the Knee-Society-Score, the range of motion, the flexion contracture as well as the posterior and anterior drawer with the KT 1000. The laxity was defined as the sum of the anterior and posterior drawer.


RESULTS
The mean values measured were 2.9 mm for the anterior drawer, 1.9 mm for the posterior drawer and 4.8 mm for the laxity. The total patient population reached 81.3 points in the Knee Score, 70.9 points in the Function-Score and 80.7 points in the HSS-Score. The medium range of motion was determined as 103.5 degrees, the medium flexion contracture as 3.5 degrees. For an anterior drawer of > 6 mm and a posterior drawer of < 1 mm the results deteriorated significantly. A laxity of 8-11 mm gave the best score results.


CONCLUSIONS
An anterior drawer of < 6 mm, a posterior drawer of 2-5 mm and a laxity of 8-11 mm seem to be recommendable for unconstrained knee arthroplasty.
Pellengahr
C
C
Orthopädische Klinik und Poliklinik, Ludwig-Maximilians-Universität München.
Jansson
V
V
Dürr
H R
HR
Refior
H J
HJ
D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis*; D011474:Prosthesis Design; D011475:Prosthesis Failure