The effect of local bone mineral density on the rate of mechanical failure after surgical treatment of distal radius fractures: a prospective multicentre cohort study including 249 patients

Introduction: The aim of this prospective, multicentre study was to evaluate the influence of local bone mineral density (BMD) on the rate of mechanical failure after locking plate fixation of closed distal radius fractures. Materials and methods: Between June 2007 and April 2010, 230 women and 19 men with a mean age of 67years were enrolled. Dual energy X-ray absorptiometry measurements for BMD of the contralateral distal radius were made at 6weeks post-surgery. Follow-up evaluations at 6weeks, 3months and 1year included wrist mobility and strength as well as standard radiographs. Any local bone/fracture or implant/surgery-related complications were documented. The Disability of the Arm, Shoulder, and Hand (DASH), Patient Rated Wrist Evaluation (PRWE), and EuroQol-5D scores were also recorded at the nominated time points. Results: Nine patients were reported with mechanical failure at an estimated risk of 3.6%. The BMD measurements were generally low for the study population with no difference between patients with (0.561g/cm2) and without (0.626g/cm2) mechanical failure (p=0.148). None of the patients achieved their pre-injury functional level and quality of life status after 1year. 1-year DASH and PRWE scores as well as the difference in maximum grip strength of the affected wrist relative to the contralateral side were significantly higher for patients with mechanical failure (p≤0.036). Conclusions: Our study could not identify a clear association between bone mineral density status and the risk of mechanical failure. Although the risk for mechanical failure after treatment of distal radius fractures with palmar locking plates is low, these complications must be avoided to prevent negative impact on long-term patient functional and quality of life outcome