Degenerative Spine, a Hip Replacement, and a Height Loss
A 79-year-old woman is referred for DXA after a low-trauma wrist fracture. She is 157 cm tall and reports she was 162 cm at age 50. On the printout, L1-L4 averages a T-score of -2.7, but L2 and L3 show dense sclerotic endplates and bridging osteophytes; L1 and L4 look clean with T-scores of -1.6 and -1.5. The instant vertebral assessment image shows wedge deformity at T8 and a biconcave T11. Total hip T-score is -1.8 and femoral neck -2.0 on the right; the left hip was replaced 6 years ago. Her 33% radius T-score is -2.9. She asks whether she has osteoporosis and whether she needs 'the bone shot' her neighbor receives.
1. Which T-score or T-scores would you use to make the diagnosis in this patient, and how do you handle the spine?
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Diagnosis is made from the lowest valid T-score among the lumbar spine (valid vertebrae only), total hip, and femoral neck. Radius is not used for diagnosis when a valid hip is available.
- L2 and L3 must be excluded. Sclerotic endplates and bridging osteophytes falsely raise measured BMD. Including them inflates the average and hides disease.
- Do not diagnose from a single vertebra. With L2 and L3 gone, the remaining L1 and L4 average (-1.6/-1.5 here) may be reported, but it must be labeled with the actual levels analyzed, e.g., 'L1-L4 (L2, L3 excluded)' - not passed off as a standard L1-L4 region.
- Left hip is invalid because of the arthroplasty; hardware in the region of interest invalidates BMD.
- Valid sites: femoral neck -2.0, total hip -1.8, spine (L1, L4) about -1.6. The lowest valid value is the femoral neck at -2.0, which is in the low-bone-mass range by T-score alone.
- The 33% radius at -2.9 should not be used to reclassify her when a valid hip exists; note it, but do not let it drive the diagnosis.
Document every exclusion and the reason on the report.
2. How do you interpret the height loss and the vertebral findings, and what action follows?
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Treat these as findings that change the patient's risk category, not as incidental text on a printout.
- Height loss of 5 cm exceeds the 4 cm threshold that should trigger suspicion of vertebral fracture; combined with the wedge at T8 and biconcave T11 on VFA, this is presumptive vertebral fracturing until proven otherwise.
- VFA is a screening tool, not a diagnostic radiograph. Recommend dedicated lateral spine imaging (radiograph or, where available, a definitive VFA read by a qualified interpreter) to confirm and characterize the deformities.
- Degenerative change does not protect her. Osteophytes inflate the DXA number, so her true spinal BMD is likely lower than measured - the artifact works against her, not for her.
- Escalate: communicate the height loss, the VFA findings, and the wrist fracture to the referring clinician the same day; these are fragility fractures and belong in the fracture-risk discussion.
3. How do you answer her two questions: do I have osteoporosis, and do I need the bone shot?
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Answer at the level of risk, not just the letter grade.
- By T-score alone her lowest valid value (femoral neck -2.0) reads as low bone mass, not osteoporosis. Say that plainly so she is not confused by the spine number on the printout.
- Clinically, however, a low-trauma wrist fracture plus probable vertebral fractures means she has osteoporosis in the sense that matters - she has already had fragility fractures. A T-score is a snapshot of density, not a complete measure of risk.
- Treatment is a physician decision based on fracture risk (prior fractures, age, FRAX-type inputs), not on a single number. Do not promise or veto a specific drug.
- Practical handoff: give her the report with the excluded levels explained in plain language, encourage her to ask her clinician about fracture-risk assessment, calcium and vitamin D intake, fall prevention, and what the 'bone shot' actually is. Avoid framing the scan as 'your bones are fine' or 'you definitely need an injection' - neither is yours to say.