1st Joint ESMAC-GCMAS Meeting - Análise de Marcha
1st Joint ESMAC-GCMAS Meeting - Análise de Marcha
1st Joint ESMAC-GCMAS Meeting - Análise de Marcha
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O-57<br />
DYNAMIC FUNCTION AFTER ANTERIOR CRUCIATE LIGAMENT<br />
RECONSTRUCTION IS RELATED TO GRAFT CHOICE<br />
Webster Kate Dr, Feller Julian Assoc. Prof., Joanne Wittwer Ms.<br />
Musculoskeletal Research Centre and Gait CCRE, La Trobe University, Melbourne Australia<br />
Summary/Conclusions<br />
In this study clear differences were observed in the knee kinematic and kinetic profiles between<br />
patients who had un<strong>de</strong>rgone hamstring or patellar tendon anterior cruciate ligament (ACL)<br />
reconstruction. Patients with patellar tendon grafts <strong>de</strong>monstrated reduced external knee flexion<br />
moments whereas patients with hamstring grafts <strong>de</strong>monstrated reduced external knee extension<br />
moments. These results suggest that there are graft-specific differences in knee biomechanics<br />
after ACL reconstruction that appear to relate to the donor site.<br />
Introduction<br />
ACL reconstruction is a common procedure. However, <strong>de</strong>bate continues as to whether the<br />
patellar tendon (PT) or the hamstring tendon (HS) graft is preferable. A number of studies have<br />
examined the effect of ACL reconstruction on joint kinematic and kinetic patterns during gait.<br />
These have shown that although there is a ten<strong>de</strong>ncy towards gait normalization after the<br />
reconstructive procedure, altered moments about the knee in the flexion-extension axis still<br />
persist [1-4]. It has been suggested that abnormal gait pattens might have implications for the<br />
long term <strong>de</strong>velopment of pathologic knee conditions [4, 5]. However, in the majority of these<br />
studies, only patients who had received a PT graft were examined. Therefore, the purpose of this<br />
study was to investigate biomechanical differences associated with the use of both HS and PT<br />
grafts during walking and also during higher impact activities that involved single limb landing.<br />
Statement of Clinical Significance<br />
As both hamstring and patellar tendon grafts are used for ACL reconstruction, it is clinically<br />
relevant to un<strong>de</strong>rstand the biomechanical differences in knee function associated with each graft.<br />
The reduced knee flexion angles and moments we observed in the patellar tendon patients may<br />
place this group at greater risk of <strong>de</strong>veloping <strong>de</strong>generative joint changes.<br />
Methods<br />
Two experiments were conducted. In experiment 1, the gait patterns of 17 PT patients, 17 HS<br />
patients and 17 controls matched for activity were compared. In experiment 2, single-limb<br />
landing patterns for vertical and horizontal hops were compared between 17 PT patients, 17 HS<br />
and 12 control subjects. ACL patients were tested 9 to 12 months following surgery. For both<br />
experiments a 3-dimensional motion analysis and force plate system was used to <strong>de</strong>termine<br />
sagittal plane kinematics and kinetics of the lower limb.<br />
Results<br />
In experiment 1 (walking) there were significant differences in the moments about the operated<br />
knee that related to graft type. The PT patients had a reduced external knee flexion moment at<br />
mid stance whilst the HS patients had a reduced external extension moment at terminal stance.<br />
Experiment 2 (landing) results for both the horizontal and vertical hops also showed a reduction<br />
in the external flexion moment about the operated knee for the PT group compared to the nonoperated<br />
si<strong>de</strong>, the control subjects and the operated si<strong>de</strong> of the HS patients, but no differences<br />
compared with the operated si<strong>de</strong> of the HS group. In the PT group the maximum knee flexion<br />
angle in the operated limb was also reduced compared to the non operated limb for both<br />
horizontal and vertical hops. During landing from a horizontal hop the external knee flexor<br />
moment was the predominant moment for the control group but not for patient groups. For the<br />
vertical hop the ankle dorsiflexion moment predominated in all subject groups. The patient<br />
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