Background: The association between ankle fractures in elderly patients and low bone mineral density (BMD) has recently been recognized, but the effect of BMD on the postoperative outcome of these fractures is unknown. The aim of this study was to investigate the effect of BMD on the postoperative outcome of ankle fractures in elderly patients to evaluate the need for BMD screening.
Methods: We retrospectively reviewed 48 patients aged 65 years or older who had ankle fractures and underwent dual-energy x-ray absorptiometry to assess BMD after surgical treatment of the fracture. Postoperative outcomes were assessed using the Olerud-Molander Ankle Score (OMAS), visual analog scale (VAS) score for pain, Kellgren and Lawrence (K&L) grading scale score, and quality of fracture reduction. The correlation between the BMD and the outcome measures at 12 months after surgery was analyzed using the Pearson correlation coefficient.
Results: The mean absolute value of BMD was 0.6 ± 0.1 g/cm2 (T-score, -1.5 ± 1.2) at the femoral neck and 0.8 ± 0.2 g/cm2 (T-score, -1.2 ± 1.5) at the lumbar spine. Osteoporosis was present in 33% of female patients and in 11% of male patients. At 12 months after surgery, the OMAS was 70 ± 17 and the VAS score for pain was 18 ± 17. Of the patients, 20, 21, 5, 1, and 1 had K&L grades of 0, 1, 2, 3, and 4, respectively. None of the clinical and radiographic outcome measures were correlated with the BMD values of the patients.
Conclusion: The postoperative outcome of the ankle fractures in elderly patients at 12 months after surgery showed no correlation with femoral neck or lumbar spine BMD at the time of fracture.
Level of evidence: Level III, retrospective comparative study.
Keywords: absorptiometry; aged; bone density; treatment outcome.