Herbert screw fixation and reverse guided drillings, for treatment of types III and IV osteochondritis dissecans

We evaluated the outcome in 10 young patients, ages ranging from 15 to 26, with types III and IV osteochondritis dissecans of the knee, treated with Herbert screws fixation and reverse guided drillings. The disease involved the medial femoral condyle in eight patients and the lateral in two. Diagnosis and preoperative planning based on plain radiographs (AP, lateral and tunnel view) and MRI (in seven patients). Fixation of the fragment with Herbert screws using a mini-arthrotomy technique and additional reverse drillings behind the crater of the lesion using the ACL aiming devise were performed in all patients. Post-operatively, no weight bearing was recommended for at least three months. The follow-up ranged from 15 months to 38 months (mean 27 months). According to the subjective questionnaire of the International Cartilage Repair Society (ICRS) scale, seven patients had normal knees, two had nearly normal knees and one abnormal. The Lysholm Knee score ranged 65-96 points (mean 88 points). All patients except one returned to their previous activities and they were satisfied with the result. Radiological union of the fragment was found in 9/10 patients (six grade III, three grade IV). Progressive flattening of the injured femoral condyle was noticed in two patients (grade III). Securing the lesion using Herbert screws in combination with reverse guided drillings seems to be an effective treatment choice for detached or displaced osteochondral fragments.