Assessment of the Osteoporotic Spine and Implications for Treatment

This section describes the various imaging modalities that exist today for evaluating bone density and thereby diagnosing osteopenia or osteoporosis. Osteoporosis is the most common metabolic abnormality of the bone, and fragility fractures due to osteoporosis have a tremendous impact in our aging society. Dual-energy X-ray absorptiometry scans, digital X-ray radiogrammetry, quantitative computed tomography, quantitative ultrasound, and magnetic resonance imaging are discussed in some detail. While the evaluation of bone density is important in any surgical treatment of the spine that involves decompression (which may remove some stabilizing tissues, imparting a greater load on remaining bony elements) or instrumentation (that depend on implant-bone fixation), the biggest clinical impact these imaging modalities have is in the diagnosis and subsequent management of osteoporotic vertebral compression fractures, which is the most common fracture of fragility that affects the elderly population.