ACL Reconstruction with a New Generation of LARS Artificial Ligament

Patient will answer the questionnaire KOOS (Knee Injury and Osteoarthritis Outcome Score) pre-surgery, 90, 180 and 365 days post-surgery.

This is a knee-specific instrument, developed to assess the patients' opinion about their knee and associated problems both on short-term and long-term. The KOOS questionnaire includes five dimensions that are relevant to patients: pain, symptoms, daily activities, sports and recreation, and quality of life. Each of these dimensions is scored separately, using a Likert scale with five possible answers ranging from 0 (no problems) to 4 (extreme problems). The scores for each dimension are calculated by summing the answers to the relevant questions. The resulting scores are then transformed to a scale from 0 to 100, with 0 representing extreme knee problems and 100 representing no knee problems. Answers to the questionnaire pre-surgery will be compared to the answers collected at 90, 180 and 365 days post-surgery.

The Visual Analogue Scale (VAS) will be used to measure the intensity or frequency of various symptoms, most commonly pain. Patients will be asked to mark a point on the line that represents their perception of their current state pre-surgery, 90, 180 and 365 days post-surgery. Using a ruler, the score is determined by measuring the distance (mm) on the 10-cm line between the "no pain" anchor and the patient's mark, providing a range of scores from 0-100. A higher score indicates greater pain intensity. Scores obtained pre-surgery will be compared to the scores obtained at 90, 180 and 365 days post-surgery.

The IKDC Subjective Knee Evaluation Form is used to evaluate the knee. The questionnaire looks at 3 categories: symptoms, sports activity and knee function. The symptoms subscale helps to evaluate things such as pain, stiffness, swelling and giving-way of the knee. The sports activity subscale focuses on functions such as; going up and down the stairs, rising from a chair, squatting and jumping. The knee function subscale asks patients 1 simple question - how is their knee at present versus how was their knee prior to injury.

Scores are obtained by summing the individual items and then transforming the crude total to a scaled number that ranges from 0 to 100. Higher scores indicate higher levels of function and lower levels of symptoms. Patients will complete the IKDC form pre-surgery, 90, 180 and 365 days post-surgery. Scores obtained pre-surgery will be compared to the scores obtained at 90, 180 and 365 days post-surgery.

Posterior-anterior knee laxity is measured using a KT-1000 arthrometer. The subject lies in a supine position with the knee flexed about 20°, a support is placed below the knee proximal to the popliteal space. The subject is told to relax in this position. The arthrometer is then placed above the tibia and attached firmly by two bands. After adjusting the zero, the tibia is pulled anteriorly using the handle on the arthrometer. An audible indication will be noticed at 15, 20 and 30 pounds (approx. 6, 9 and 13kg) of force. Moreover, a manual maximum measure is performed pulling the tibia with a hand on the back of the shank, until the foot is raised. Displacement is measured in millimeters and compared with the healthy leg measurements. The difference between the legs should be 1mm - 15mm.

Knee laxity will be measured pre-surgery, 45, 90, 180 and 365 days post-surgery. Values at pre-surgery will be compared to the ones from post-surgery mesurements.

Knee flexors-extensors strength assessment will be measured using an Isokinetic machine and superficial EMG evaluation. The subject performs an isokinetic concentric evaluation with a fixed velocity of 90°/s with a range of motion of 0-90° of knee flexion. After warming-up, subject is asked to sit on the resting chair of the dynamometer, the subject is then secured with body straps. The starting position is 90° flexion for the knee and 90° for the hip joint. The subject is instructed to extend the knee till 0° flexion and then to flex the knee back at 90° with maximum exertion. The test is performed firstly on the healthy side and then on the injured side. Peak forces are compared between the legs.

Knee flexors-extensors strength will be measured pre-surgery, 90, 180 and 365 days post-surgery. Values at pre-surgery will be compared to the ones from post-surgery mesurements.

The subject is asked to stay still on a force platform for 10 seconds, firstly standing only on one leg with the arms folded across the chest. The test is then repeated on the other leg. The motion/change of the centre of pressure is used to quantify ellipse area to measure stability. Usually, ellipse area results for stabilometry test show differences between the healthy and the injured leg.

Stabilometry will be measured in both legs pre-surgery, 45, 90, 180 and 365 days post-surgery.