Section Spotlight
Osteoporosis and Spinal Deformity
Anson G. Bautista, MD
Dwight D. Eisenhower Army Medical Center Fort Eisenhower, GA
Justin L. Reyes, MS
Columbia University Medical Center NewYork-Presbyterian Och Spine Hospital New York, NY
Joseph M. Lombardi, MD
Columbia University Medical Center NewYork-Presbyterian Och Spine Hospital New York, NY
Tony Tannoury, MD
Boston Medical Center Boston, MA
Lawrence G. Lenke, MD
Columbia University Medical Center NewYork-Presbyterian Och Spine Hospital New York, NY
Zeeshan M. Sardar, MD
Columbia University Medical Center NewYork-Presbyterian Och Spine Hospital New York, NY
Introduction
Osteoporosis and spinal deformities pose a unique challenge for spine surgeons, necessitating a nuanced understanding of the complex interplay between bone health, deformity progression, and surgical intervention. A significant number of patients over the age of 50 undergoing spine surgery have abnormal bone mineral density.1,2,3 Patients with poor bone health are at an increased risk of surgical complications including instrumentation failure, vertebral compression fractures, sacral fractures, and proximal junctional kyphosis (PJK).2,4,5,6,7 Many of these patients are being under-treated or not treated. Moreover, many of these patients are not being screened prior to elective spine surgery; this missed opportunity is a chance to reevaluate how these patients are managed.3,8
Screening for Osteoporosis and Assessment of Bone Health
In a recent study, the recommendations of a multidisciplinary expert panel, created to establish best practice guidelines for patients with osteoporosis undergoing spinal reconstruction were reported. The consensus was that all patients over 65, independent of risk factors, should have a formal bone mineral density (BMD) evaluation. For patients between the ages of 50 and 64, BMD testing should be performed if any of the following risk factors are present: chronic glucocorticoid use, previous low-energy fracture of the hip or spine, metabolic bone disease, chronic kidney disease more than or equal to stage 3, high fracture risk as calculated by fracture risk assessment tool (FRAX), prior failed spine surgery, alcohol use of three or more drinks per day, Vitamin D deficiency, current smoking, being wheelchair-bound, current cancer treatment, and diabetes mellitus. For patients under the age of 50, BMD testing should be performed if the following risk factors are present: chronic glucocorticoid use, prior low-energy fracture, metabolic bone disease, current cancer treatment, or chronic kidney disease.9
The gold standard for evaluating bone health has been a dual-energy X-ray absorptiometry (DEXA) scan of both the lumbar spine and hip. DEXA is the preferred bone health evaluation due to its wide availability and familiarity to endocrinologists, rheumatologists, and primary care physicians. However, DEXA is inaccurate with scoliosis curves of >15 degrees, osteophytosis of the spine, or spinal instrumentation.10,11 In these cases, DEXA of the hip is recommended, though the presence of hip arthroplasty components can interfere with study accuracy. Opportunistic assessment by CT-based Hounsfield units (CTHU) is a useful alternative to DEXA, though CTHU should not replace DEXA in patients who are not technically precluded.9