Loss of radial height in extra-articular distal radial fracture following volar locking plate fixation.

BACKGROUND

Radial height is an important prognostic factor in treating distal radius fracture. However, does further collapse of radial height in distal radius fractures after with volar locking plate fixation have a great impact on the prognosis? The present study aimed to elucidate radial height loss and determine the associated risk factors after open reduction and internal fixation with volar locking plate in patients with extra-articular distal radius fractures.

HYPOTHESIS: Patients with radial height collapse after fracture reduction and internal fixation with a volar locking plate may have poor outcomes.

METHODS

Data of 87 patients (21 male) undergoing surgery for acute extra-articular distal radius fractures (AO: 23-A2 or 23-A3) between February 2014 and July 2016 were evaluated retrospectively. Patients were divided into two groups by radial height loss. Potential risk factors were tested by Pearson correlation coefficients. Stepwise multiple regression logistic analysis determined significant independent risk factors for extra-articular distal radius fractures. Clinical evaluation was performed by the same surgeon by determining wrist ROM. Grip strength was measured with a Jamar dynamometer and compared with non-affect wrist in percentage. In addition, all the patients were asked to grade modified Mayo wrist score and Visual Analogue Scale (VAS) score. These findings were recorded postoperative 1 year of follow-up.

RESULTS

Mean radial height loss was 1.3±0.9mm. Age (ß=0.002, p=0.003), postoperative ulnar-positive deformity (ß=0.107, p<0.001), DEXA (ß=-0.015, p=0.008), and shortest diameter of distal fracture fragment in AP and lateral views (ß=-0.050, p=0.037; ß=-0.080, p=0.043) were significantly associated with radial height loss. As for the outcome of clinical prognosis, though radial height collapse group had poorer wrist range of motion, there was no statistical difference. Besides, there were no significant differences in grips strength and VAS score between these two groups. However, in regards of modified Mayo wrist score, the percentage of patients with poor outcomes is significant higher in radial height collapse group (p=0.039). Moreover, all patients with poor outcomes in radial height collapse groups were older than 65-year-old.

DISCUSSION: Radial height loss is noted in patients undergoing open reduction and internal fixation with volar locking plate for extra-articular distal radius fractures. Risk factors for radial height collapse include advanced age, poor bone quality, shortest distance between fracture site and articular surface and postoperative ulnar-positive deformity.

LEVEL OF EVIDENCE: IV; non-comparative prospective study.