Which Bone is Most Affected by Osteoporosis
The vertebral spine is the most commonly affected site in osteoporosis, representing the earliest and most frequent location for osteoporotic fractures, particularly in postmenopausal women and older adults. 1, 2
Epidemiology and Clinical Significance
Vertebral fractures are the earliest and most common osteoporotic fractures, with prevalence increasing steadily from 20% in 50-year-old postmenopausal women to 64.5% in older women. 1
The spine becomes affected first because trabecular bone (which predominates in vertebrae) has higher metabolic activity and remodels more rapidly than cortical bone, making it more susceptible to the accelerated bone resorption that characterizes osteoporosis. 2
Only one in three vertebral fractures is diagnosed clinically, as many occur without severe trauma and remain asymptomatic or present with subtle symptoms like back pain, height loss, or posture changes. 1
Major Osteoporotic Fracture Sites
While the spine is most commonly affected, osteoporosis impacts multiple skeletal sites with varying clinical significance:
Major osteoporotic fracture (MOF) sites include the hip, spine, wrist (forearm), and shoulder (humerus), as defined by current screening and treatment guidelines. 3, 4
The European Medicines Agency has expanded the definition to include the distal femur, proximal tibia, pelvis, and multiple ribs as major osteoporotic fracture sites. 4
Hip fractures carry the highest morbidity and mortality risk despite being less common than vertebral fractures, with hip fractures significantly affecting quality of life and survival. 5, 6
Fracture Risk Cascade
Women with vertebral fractures face dramatically elevated risk of subsequent fractures: 3.4 times higher risk for hip fracture and 12.6 times higher risk for new vertebral fractures. 1
Nearly 20% of women experience another fracture within 1 year after an initial vertebral fracture, with the highest imminent fracture risk occurring in the 1-2 years following any major osteoporotic fracture. 1, 4
The relative risk of death following vertebral fracture is almost 9 times higher, underscoring the serious clinical consequences even though these fractures are often clinically silent. 1
Screening and Diagnostic Implications
Bone mineral density screening via DEXA should measure the femoral neck, total hip, and lumbar spine, as these are the primary sites for diagnosis and fracture risk assessment. 7, 8
The femoral neck serves as the reference site for epidemiological studies, though fracture risk at a specific site is best predicted when bone density is measured at that site. 8, 3
If degenerative changes affect the spine (which can falsely elevate BMD values), the hip becomes the primary diagnostic site. 8
Common Clinical Pitfalls
Do not dismiss back pain or height loss in at-risk patients—these may represent undiagnosed vertebral compression fractures that warrant immediate evaluation and treatment. 1, 2
Remember that 60% of osteoporotic fractures occur in patients with T-scores higher than -2.5, so any fragility fracture confirms skeletal fragility regardless of BMD measurement. 4
Any fragility fracture in an older adult warrants full osteoporosis evaluation and treatment, not just fractures at "traditional" sites. 4