Second-look arthroscopic and magnetic resonance analysis after internal fixation of osteochondral lesions of the talus

The purpose of this study was to evaluate cartilage quality after internal fixation of osteochondral lesion of the talus (OLT) using second-look arthroscopies and MRIs. Thirty-four patients underwent internal fixation of OLTs involving large bone fragments. Twenty-one of these patients underwent second-look arthroscopies and 23 patients underwent MRIs postoperatively. The arthroscopic findings were assessed using the International Cartilage Repair Society (ICRS) grading system, and the MRI findings were evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Five of the patients who underwent second-look arthroscopies showed normal cartilage, 12 showed nearly normal cartilage, 3 showed abnormal cartilage, and 1 showed severely abnormal cartilage, according to the overall ICRS repair grades. All the patients who achieved bone fragment union showed normal, or nearly normal cartilage upon second-look arthroscopy. The ICRS and MOCART scores were significantly higher for the patients with bone fragment union compared to those with nonunion (ICRS scores: 10.3 ± 1.5 vs. 6.0 ± 2.0, p < 0.001, MOCART score: 88.3 ± 10.0 vs. 39.0 ± 20.4, p < 0.001). Low signal intensities of the bone fragments on preoperative T1-weighted MRIs were not associated with nonunion (Fisher's exact test, p = 0.55), and the signal intensities increased postoperatively to levels similar to the underlying talus when bone union was achieved. Second-look arthroscopy and MRI showed normal, or nearly normal, cartilage after internal fixation of OLTs when bone union was achieved. The nonunion of bone fragments resulted in inferior cartilage quality.