Are Radiographic Characteristics Associated With Outcome in Surgically Treated Distal Radius Fractures?

PURPOSE: Evidence to date shows that distal radius fracture displacement measured on radiographs does not correlate with patient-reported outcomes. Quantitative 3-dimensional computed tomography (CT) (Q3DCT) potentially captures fracture displacement more accurately. We aimed to assess the independent association between radiographic, CT, and Q3DCT measures of residual displacement and change in disability, quality of life, range of motion (ROM), and grip strength 12 weeks and 1 year after volar plating of intra-articular distal radius fractures. METHODS: We performed a secondary analysis of data from a prospective multicenter trial. Seventy-one patients underwent volar plating of their AO Foundation/Orthopaedic Trauma Association type B or C distal radius fracture and were available at 12 weeks; 67 (94%) were available at 1 year. We recorded demographics, postoperative periapical radiographs (radial height, ulnarward inclination, ulnar variance, gap, and step off), lateral radiographs (palmar tilt, scapholunate angle, teardrop angle, and anteroposterior distance), postoperative CT scans (gap [coronal, sagittal and axial]) and step off [sagittal and coronal]), and in 3-dimensional models (number of articular fragments, mean fragment articular surface area, 3-dimensional fragment displacement, and gap surface area). Radiographs and CT scans were obtained within 10 working days after fracture fixation. Outcome measures were change in Patient-Rated Wrist Evaluation (PRWE) scores, EuroQol Group 5-Dimension questionnaire (EQ5D) results, grip strength, and composite wrist ROM at 12 weeks and 1 year compared to preinjury level. RESULTS: At 1 year, greater recovery in PRWE scores was independently associated with older age. Greater recovery in composite ROM at 1 year was associated with injury to the dominant side and less step-off on posteroanterior radiographs. CONCLUSIONS: Less posteroanterior step-off was associated with a small improvement in composite wrist ROM at 1 year. This should be considered when counseling patients on the risks and benefits of surgical treatment when radiographic and CT measures of displacement fall within the range found in this study, and in older, low-demand patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.