Incidence and predictors of dorsal comminution in older adults with low-energy distal radius fracture.

PURPOSE

To identify the incidence of dorsal comminution using computed tomography (CT) images and identify predictors of this phenomenon in older adults with low-energy distal radius fractures (DRFs).

METHODS

A total of 150 patients aged > 50 years with fall-induced dorsally angulated DRFs were enrolled in this study. Patients were divided into two groups based on the presence of dorsal comminution, defined as a metaphyseal void of greater than one-third of the maximum posterior to anterior depth of the bone on at least three cuts in the sagittal plane on post-reduction CT images. Data on participants' basic demographics, including age, sex, body mass index (BMI), and AO classification of DRFs, were collected. Bone mineral density (BMD) was assessed using T-scores of the femoral neck, and cortical thickness of the distal radius was determined from plain post-reduction radiographs. Radiological parameters and combined ulnar fractures were measured on plain pre-reduction radiographs.

RESULTS

Among study participants, 91 (61%) had dorsal comminution, whereas 59 (39%) had no dorsal comminution on CT images. Both patient groups were compared based on presence of dorsal comminution, and showed no significant differences in age, sex, BMI, BMD, or cortical thickness on radiographs. However, all radiological parameters were better in the no dorsal comminution group than in the dorsal comminution group, and the proportion of patients with combined ulnar fractures was higher in the dorsal comminution group. In the multivariate analysis, the presence of combined ulnar fractures was the only significant predictor of dorsal comminution (p = 0.029, odds ratio = 2.267, 95% confidence interval: 1.085-4.736).

CONCLUSION

The incidence of dorsal comminution is relatively high in patients with low-energy DRFs aged > 50 years. In particular, the presence of combined ulnar fractures is closely associated with dorsal comminution of DRFs. Thus, surgeons should exercise caution when evaluating this phenomenon.