DEXA sensitivity analysis in patients with adult spinal deformity

Area of Science:

• Orthopedics
• Radiology
• Endocrinology

Background:

• Adult spinal deformity (ASD) often coexists with osteoporosis, increasing surgical risks.
• Accurate detection of low bone mineral density (BMD) is vital for managing ASD patients.
• Standard hip and spine dual-energy x-ray absorptiometry (DEXA) scans can be inaccurate in ASD patients.

Purpose of the Study:

• To evaluate the utility of forearm DEXA scans in addition to hip scans for detecting low BMD in ASD patients with osteoporosis.
• To determine if forearm DEXA scans improve diagnostic accuracy compared to hip scans alone.

Main Methods:

• Retrospective study analyzing DEXA scan data from 286 adult spinal deformity patients (2016-2018).
• Compared T-scores from hip and forearm DEXA scans to identify low bone density (osteopenia/osteoporosis).
• Extrapolated the frequency of missed diagnoses when relying solely on hip or spine T-scores.

Main Results:

• Forearm DEXA scans were more sensitive in detecting osteopenia or osteoporosis in 41.2% of cases compared to hip scans.
• In over 17% of patients, forearm scans identified low BMD that would have been missed using only hip data.
• No statistically significant difference was found between hip and forearm T-scores, but forearm sensitivity was higher.

Conclusions:

• Forearm DEXA scans are valuable for accurately assessing BMD in ASD patients with osteoporosis.
• Clinicians should survey at least two locations (hip and forearm) for DEXA scans in ASD patients.
• Relying on single-site hip scans can lead to frequent and costly misdiagnoses in this population.