[Correlation between computed tomography and isokinesis in patients with reconstructive surgery of anterior cruciate ligament of the knee].
OBJECTIVE
The aim of this study was to correlate the length (measured by computed tomography) of the anterior cruciate neoligament following knee surgery with the time required by the flexors-extensors of the knee to reach isokinesis (measured using an isokinetic method).


METHODS
Twenty-five patients (all males, median age 25.4 years), who had undergone surgical repair of the anterior cruciate ligament (ACL), were assessed by computed axial tomography (CT) and isokinetic tests a mean of 6.3 months after their operation. The following isokinetic parameters were calculated: time to reach isokinesis in flexion, time to reach isokinesis in extension, flexion strength, and extension strength. Mean values were calculated from all the values recorded during the test cycles performed. The CT examinations, after lateral scanograms, were carried out with 1 mm contiguous axial scans parallel to the tibial plate. It was possible to assess the integrity of the neoligament which was measured from a section of the tibial plate above the tibial cartilage to its insertion in the intercondylar furrow.


RESULTS
As expected, all the values recorded from the healthy knee were significantly different from those recorded on the operated side. As far as concerns analysis of any correlations, there were good correlations between the time to reach isokinesis in extension and the length of the ACL both on the operated side (r=.62) and the healthy side (r=.69), whereas the correlations between the length of the ACL and all other measurements were moderate or very weak (from 0.44 to 0.03).


CONCLUSIONS
That the isokinetic measurements show an increased time for the extensor muscles of the operated knee to reach isokinesis is related to altered biomechanics of the passage of the tibia from a posterior translaction position to one of an anterior translaction that is, to anterior displacement of the tibia during extension of the knee, which leads to the prolonged time. The correlation between this time and the length of the ACL, as measured by CT, offers the possibility of being able to monitor the outcome of cruciate ligament repair periodically during various phases of rehabilitation treatment and of only using control CT examinations if there are any complications and/or problems.
Felicetti
G
G
Divisione RRF I, Fondazione Salvatore Maugeri, IRCCS, Clinica del Lavoro e della Riabilitazione, Istituto Scientifico di Montescano, Italy. gfelicetti@fsm.it
Abelli
F
F
Zambianchi
M
M
Maini
M
M
Maestri
R
R
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging* / Q000502:physiology / Q000601:surgery*; D001696:Biomechanical Phenomena; D003627:Data Interpretation, Statistical; D015444:Exercise; D005080:Exercise Test; D005500:Follow-Up Studies; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging* / Q000502:physiology*; D008297:Male; D011859:Radiography; D013997:Time Factors
Correlazione fra tomografia computerizzata e isocinesi in pazienti operati diricostruzione di ricostruzione di legamento crociato anteriore di ginocchio.