Retrograde Drilling for Osteochondral Lesion of the Talar Dome in Juvenile Patients

Abstract

Category: Ankle, Arthroscopy Introduction/Purpose: Osteochondral lesion of the talar dome (OLT) is common condition that causes pain of ankle joint in juvenile patients. Several surgical options have been available such as excision of detached cartilage fragment, microfracture, autologous cancellous bone graft and osteochondral autografting depending on the status of OLT. Arthroscopic drilling including transmalleolar or retrograde technique could be a good option for OLT patients with stable osteochondral fragment with normal articular surface. Retrograde drilling has an advantage in preventing the iatrogenic articular cartilage injury. This study aimed to clarify the clinical outcome of the retrograde drilling for OLT in juvenile patients. Methods: Our retrospective analysis included 8 patients who underwent retrograde drilling for OLT, in 5 boys and 3 girls, with a mean age of 14.9 years (range, 11-19). Range of motion (ROM) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle- hindfoot score were evaluated as the clinical outcomes. OLTs were classified into 4 grades according to arthroscopic findings by international cartilage research society (ICRS) classification. Radiographic analysis was performed using preoperative and postoperative images. Growth plate was evaluated on plane radiographs, and the location and size of OLT were assessed on computed tomography. The high intensity area of the talus was also measured on T2 fat suppression images. Results: All 8 patients were followed with a mean follow-up period of 2 years, and they had no complication or revision surgery. The mean total ROM were 65.6° preoperatively and 67.1° postoperatively. AOFAS scale improved from 69.3 to 96.7 (p = 0.012). The ICRS 1 and 2 OLT lesions were identified arthroscopically in 5 and 3 patients, respectively. Growth plate remained open in 4 patients, and OLTs were located on the posteromedial in 7 patients, center in 1 patient. The mean size of OLT fragment was 9.8 mm, 6.8 mm and 3.5 mm in length, width and height. Coronal and sagittal T2 fat suppression images demonstrated that the high intensity area of 241.3 mm2, 554.5 mm2 at preoperative status and 190.9 mm2, 302.6 mm2 at final follow-up status. Conclusion: These findings revealed that the retrograde drilling remarkably improved clinical status in juvenile OLT patients. The high intensity area at the talus remained postoperatively, however, that did not affect clinical results. Retrograde drilling procedure should be considered for treating juvenile patients in the early period after detection of the OLT.