Differential Diagnosis for Fragility Fracture in an Older Adult Female
Single Most Likely Diagnosis
- Osteoporosis: Despite having a normal bone density measurement six months ago, osteoporosis is the most likely condition contributing to the fragility fracture. Osteoporosis can progress rapidly, and a single bone density measurement may not capture the dynamic nature of bone health. The fact that the fracture occurred after a low-impact fall (from a chair) suggests weakened bone structure, which is characteristic of osteoporosis.
Other Likely Diagnoses
- Osteomalacia: This condition, characterized by softening of the bones due to vitamin D deficiency or phosphate metabolism disorders, could contribute to fragility fractures. Although less common than osteoporosis, osteomalacia should be considered, especially if there are underlying conditions or nutritional deficiencies that could predispose to it.
Do Not Miss Diagnoses
- Bone Malignancy: Although less likely, bone malignancy (such as metastatic cancer or primary bone tumors) could weaken bones and lead to fractures. Given the potential severity and impact on prognosis, it's crucial not to miss this diagnosis. A thorough investigation, including imaging and possibly biopsy, might be necessary to rule out malignancy.
Rare Diagnoses
- Paget Disease: This chronic condition involves the breakdown and regrowth of bone tissue, resulting in deformity. While it can increase the risk of fractures, Paget disease is less common and typically presents with other symptoms such as bone pain, deformity, or elevated alkaline phosphatase levels. It would be an unusual cause of a fragility fracture without other suggestive findings.