No abstract

In a cadaveric biostatic model the pressure distribution at the weightbearing ankle has been investigated under different joint positions and stages of artificial lateral ligament dissection mimicking a supination trauma. The location of the transduced contact area, the size of these areas and amount of pressure were evaluated after application of axial load. The results showed that the location, size of contact area and the maximum transduced pressure were depending on the joint position and stage of ligament dissection. Interestingly the peak pressure was located at the medial talar rim even without lateral ligament dissection. The transduced pressure areas were located at that locations were osteochondral lesions are mostly observed. In regard to these results the etiology and pathogenesis of osteochondritis dissecans tali is discussed. It is thought that supination traumas as well as other biomechanical factors such as overweight and lax ankle ligaments have an important influence on the development of osteochondritis dissecans at least at the medial rim of the talus.

Clinical results in two groups of patients treated for osteochondrosis dissecans tali were examined in a follow-up examination: adolescents up to age 16 years versus adults. Thirteen patients were reexamined in each group. Clinical comparison revealed distinct differences between the groups. In adolescents there were eight excellent and three good results, only one fair, and one poor result. In contrast, adults demonstrated excellent results in only two and good results in five patients; five patients showed fair results and one a poor outcome. No signs of osteoarthrosis were detected in adolescents whereas in four adult patients slight radiological signs of osteoarthritis were visible. In both groups clinical and radiological results were better when the cartilage layer at the talar dome was found to be intact at the time of surgical intervention. Detectable cartilage damage at the time of operation was accompanied by a worse result at the time of follow-up examination. In conclusion, adolescents without any signs of joint locking or loose body formation should first be treated conservatively. The older the patient the shorter the period of nonsurgical treatment should be. In cases of increasing stages, joint locking, or formation of loose bodies surgical intervention is recommended.

Long-term results after surgical treatment of osteochondritis dissecans of the talar dome and joint knee are dependent on the stage of cartilage damage, the age at operation and on the surgical technique. In cases of osteochondritis dissecans of the talar dome the only loosening of a refixed osteochondral fragment was seen after glueing with acrylate. Using the classification of Arcq in 59.6% an excellent and in 18.3% a good result was observed in cases of osteochondritis dissecans at the femoral condyles. In regard to the development of osteoarthritis in 56% no signs of osteoarthritis were visible. Worst results were obtained in knee joints in which acrylate glue was used for refixation of the osteochondral fragments. In conclusion we recommend the use of fibrin glue for refixation of osteochondral fragments in cases of osteochondritis dissecans even when early mobilisation follows the operation. Because of the long-lasting resorption and barrier effect to ingrowing tissue the use of cyanoacrylate should be avoided.

26 out of 38 patients with Osteochondrosis dissecans of the talus and treated surgically were examined in a follow-up. The mean time of this postoperative follow-up after surgery was nearly 56 months. Anamnestic answers show that sport activities besides a sprained ankle joint are two of the most common factors leading to this disease. All patients without sport activities had suffered from a sprained ankle with or without ligamentous ruptur. Most of the disciplines were activities with a strong load for the ankle joints. Besides this no other etiological reason could be found in such a frequency. After surgical treatment 14 of the 22 sportsmen regained their full sport abilities, 7 of them could perform only a limited activity in sports.