[Functional ultrasound examination of the posterior cruciate ligament -- a new method of detecting ligament instability in the knee joint].
OBJECTIVE
Detection of injuries to the posterior cruciate ligament (PCL) is difficult and dismissed in many cases. Here we introduce dynamic ultrasound examination as a safe and reproducible method to detect a PCL-insufficiency with or without fixed posterior tibia position and combined injuries to the cruciate ligament complex.


METHODS
Dynamic ultrasound examination in a modified technique to Schwarz et al. was performed on 20 patients with a PCL-insufficiency (group 1) and 20 patients with an anterior cruciate ligament (ACL) insufficiency (group 2). Comparing both knee joints, we measured the resting value (RV), ventral translation value (VT) and dorsal translation value (DT). Mean value, standard deviation in mm and t-test for unpaired values were compared with each group and a healthy control population.


RESULTS
In group 1 we could distinguish patients with fixed posterior position (PCL (mfix)) who showed a pathological dorsal RV (2.96 mm) from patients without fixation (PCL (ofix),: RV = 0.7 mm). DT was significantly prolonged (PCL (mfix): 6.4 mm; PCL (ofix): 5.6 mm) compared to healthy individuals. Group 2 showed a pathological RV (2,38 mm) and a significant prolonged VT (4.19 mm). 10 patients in this group had a spontaneous ventral tibia translation (RV: 3.7 mm) and 10 patients with ACL insufficiency showed a normal resting value (RV: 0.88 mm).


CONCLUSIONS
Dynamic ultrasound examination allows us to distinguish between isolated ACL- or PCL-insufficiency and combined injuries of the cruciate ligament complex using a standardized flow sheet. PCL-insufficiency therefore can be separated into the entities of fixed posterior and partly reducible instability.
Bergenthal
G
G
Chirurgische Klinik, Bundeswehrkrankenhaus Ulm. Dr. Bergenthal@t-online.de
Schwarz
W
W
Gerngross
H
H
Friemert
B
B
D000328:Adult; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D016119:Posterior Cruciate Ligament / Q000000981:diagnostic imaging* / Q000293:injuries / Q000601:surgery; D019651:Plastic Surgery Procedures / Q000379:methods; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods