Lateral and anterior instability in acute ankle distortion. A radiologic investigation

Arthroscopic monopolar radiofrequency thermal stabilization for chronic lateral ankle instability: a preliminary report on 10 cases

This study represents a preliminary review of 10 patients having undergone arthroscopic monopolar thermal stabilization for ankle instability from October 1996 to June 1998. All patients in this study expressed mild to moderate chronic ankle instability complaints and were dissatisfied with their attempts at conservative care. Subjective clinical results were evaluated in all patients having undergone this procedure utilizing a modified version of the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale. In addition, eight of these patients underwent pre- and postoperative stress radiographs. The average age of the patient population in this study was 34.5 +/- 9.26 years. The preoperative AOFAS scores averaged 58.3 +/- 8.96 and the postoperative were 88.1 +/- 11.09 points. Patients returned to full activities on the average of 3 months. Postoperative ankle varus stress test reduced on the average of 2.8 degrees +/- 2.77 degrees, while the anterior drawer measurements reduced 4.8 +/- 1.83 mm. The reduction in anterior drawer test amounted to an approximate 60% decrease in talar excursion postoperatively. All patients who underwent this procedure achieved ankle stability and commented that they would undergo the procedure again.

Mechanics of the anterior drawer and talar tilt tests. A cadaveric study of lateral ligament injuries of the ankle

We analyzed the changes in lateral ligament forces during anterior drawer and talar tilt testing and examined ankle joint motion during testing, following an isolated lesion of the anterior talofibular ligament (ATFL) or a combined lesion of the ATFL and calcaneofibular ligament (CFL). 8 cadaver specimens were held in a specially designed testing apparatus in which the ankle position (dorsiflexion-plantarflexion and supination-pronation) could be varied in a controlled manner. Ligament forces were measured with buckle transducers, and joint motion was measured with an instrumented spatial linkage. An anterior drawer test was performed using an 80 N anterior translating force, and a talar tilt test was performed using a 5.7 Nm supination torque with intact ligaments, after sectioning of the ATFL, and again after sectioning of the CFL. The tests were repeated at 10 degrees dorsiflexion, neutral, and 10 degrees and 20 degrees plantarflexion. In the intact ankle, the largest increases in ATFL force were observed during testing in plantarflexion, whereas the largest increases in CFL force were observed in dorsiflexion. Isolated ATFL injury caused only small laxity changes, but a pronounced increase in laxity was observed after a combined CFL and ATFL injury.