BIOMECHANICS OF ANKLE LIGAMENT RECONSTRUCTION - AN IN-VITRO COMPARISON OF THE BROSTROM-REPAIR, WATSON-JONES-RECONSTRUCTION, AND A NEW ANATOMIC RECONSTRUCTION TECHNIQUE

We wanted to use biomechanical testing in a cadaveric model to compare the Brostrom repair, the Watson-Jones reconstruction, and a new anato mic reconstruction method. Eight specimens were held in a specially de signed testing apparatus in which the ankle position (dorsiflexion-pla ntar flexion and supination-pronation) could be varied in a controlled manner. Testing was done with intact ligaments and was repeated after sectioning of the anterior talofibular ligament and the calcaneofibul ar ligament and after a Brostrom repair, a Watson-Jones reconstruction , and a new anatomic reconstruction were performed. An anterior drawer test was performed using an anterior translating force of 10 to 50 N, and a talar tilt test was performed using a supination torque of 1.1 to 3.4 N-m. The forces in the anterior talofibular ligament and calcan eofibular ligament were measured with buckle transducers, and tibiotal ar motion and total ankle joint motion were measured with an instrumen ted spatial linkage. The increase in ankle joint laxity observed after sectioning of both the anterior talofibular and calcaneofibular ligam ents was significantly reduced by the three reconstructive techniques, although not always to the level of the intact ankle. Joint motion wa s restricted after the Watson-Jones procedure compared with that in th e intact ankle. Unlike the Watson-Jones procedure, the ligament or gra ft force patterns observed during loading after the Brostrom repair an d the new anatomic technique resembled those observed in the intact an kle.