Relationship Among Postoperative Arthritis, Ischemic Changes in Subchondral Bone on Postoperative MR Images, and Central Impaction Fragment on Preoperative Computed Tomography Scans in Patients With Intra-articular Distal Radius Fracture: A Preliminary Report.

Purpose: Ischemic change in the subchondral bone which is one of the causes of osteoarthritis (OA), have been observed on magnetic resonance imaging (MRI) of the knee and hip joints. The present study aimed to use MRI examine the intra-articular distal radius fractures (DRFs). Methods: Intra-articular DRFs were treated using a volar locking plate. Plain radiographs, computed tomography (CT) scans, and postoperative MRI of 35 patients were examined. The mean follow-up period was 2 years (1-3.5 years). OA was classified into four grades based on plain radiographs and CT scan. Coronal T1W MRI was used to measure the width of the low signal intensity area (LSIA) of the subchondral bone. T2W and short tau inversion recovery (STIR) MRI were also evaluated. Results: Ten patients had type C1, 5 had C2, and 20 had C3. Central impaction fragments were observed in 10 patients on preoperative CT scan. Homogeneous LSIA in the subchondral bone on coronal T1-weighted sequence MRI was observed in 17 patients. T2-weighted sequence MRI demonstrated a combination of regions with various forms and intensities. A strong correlation (r = 0.92, Conclusions: In intra-articular DRFs, the MRI results suggested that the size of the area showing ischemic changes in the subchondral bone affects postoperative OA and that the presence of a central impaction fragment may facilitate the exposure of the subchondral bone to ischemia. There was a strong relationship between the presence of a central impaction fragment and ischemic change in subchondral bone and postoperative osteoarthritis. Type of study/level of evidence: Prognostic IV.