Medical doctors rely on evidence from scientific studies to help guide their treatment decisions. Without evidence, they fall back on consensus-based best practice. That means they do what they have seen works well and what others have reported based on surveys and questionnaires. Sometimes there’s a gap between what the evidence shows and what the current practice is. As this study shows, that’s what may be happening for patients undergoing spinal surgery who have osteoporosis.
Osteoporosis means the bones are less dense than normal. They have less bone mass than they should. That makes them fragile and can put them at risk for fragility fractures. A fragility fracture means the bone breaks without a traumatic event or unexpected force. Just the stress of movement and everyday activities causes the bone to break.
For the surgeon who is performing spinal fusion or fracture care for someone with metabolic bone disorders like osteoporosis, osteoporosis can lead to failure of the procedure. It would be a good idea to find out before performing spinal surgery if a patient is osteoporotic or has osteomalacia. Osteomalacia refers to a softening of the bones from a mineral deficiency (often a lack of Vitamin D).
Pre-operative osteoporosis screening can be done by ordering several tests. One is the dual-energy X-ray absorptiometry (DEXA or DXA scan). This test is a reliable way to gauge bone density by scanning the bone and determining mineral content. Measurements can be taken from the wrist or heel with a portable scanning device. For a more complete and accurate bone assessment, a scan of the hip and spine can be done. Those two areas tend to lose bone mass more rapidly than the peripheral areas of wrist or heel. Blood can also be drawn and tested for vitamin D levels, parathyroid hormone, and calcium (all important ingredients for strong bones).
To document spine surgeons’ practices in this area, a survey was conducted of spine surgeons attending a special spinal disorders conference in Canada. Surgeons completed a 10-question survey asking about their treatment practices when it comes to treating patients with fragility fractures of the spine. The survey was designed to find out how often and when surgeons perform routine osteoporosis/osteomalacia screening assessments of these patients.
They were asked if they routinely order a DEXA scan before doing a spinal fusion on someone who might have osteoporosis. They were asked if they routinely order blood work to check vitamin D, parathyroid hormone, and calcium levels on anyone at risk for osteoporosis. They were also asked if they refer patients to other specialists for an osteoporosis workup. Participating surgeons were asked to explain their policies and/or give reasons why they did not incorporate these screening tools in their routine practice.
About 30 per cent of the surgeons were neurosurgeons with advanced training. The remaining 70 per cent were orthopedic surgeons who had completed a spine fellowship. Everyone worked in a private practice or academic setting with the majority (68%) in private practice. The level of experience varied from less than five years in practice (about one-third of the group) to more than 15 years of experience (one-third of the group). The remaining surgeons had between five and 15 years of experience.
An analysis of the data collected showed that DEXA scans were ordered most often for patients with vertebral compression fractures or for odontoid fractures. The odontoid is a pillar of bone that’s part of the second cervical vertebrae. The odontoid fits up inside the first cervical vertebra from below. The first cervical vertebra is a circular ring of bone that fits over the odontoid like a collar. Surgeons were much less likely to order any blood work for these patients. Level of expertise and training didn’t seem to dictate who ordered DEXA scans.
Similar results were reported for surgeons treating patients with spinal fusion. DEXA scans were more likely to be ordered when the surgeon was planning to use metal plates, screws, rods, or other hardware to hold the spine together. But again, the use of metabolic bone markers such as vitamin D, parathyroid hormone, or calcium was not relied upon. It didn’t matter if it was a neurosurgeon, orthopedic surgeon, someone in private practice, or in an academic program — those lab values were not routinely ordered. The reasons for this varied from unfamiliarity with what the test results mean to the belief that there wouldn’t be any change in treatment, so there’s no need to order extra tests.
For patients with pseudoarthrosis after spinal fusion, the use of DEXA scans and lab values for metabolic bone markers was slightly more. Pseudoarthrosis refers to patients who still have some movement at the fusion site after healing is complete. Neurosurgeons and all surgeons with more experience were more likely to rely on bone laboratory tests for this patient population group. The surgeons completing the survey said they would refer patients with osteoporosis for specialty care before surgery when instrumentation was going to be used.
The results of this study confirm that osteoporosis is an undertreated condition in many older adults who have already had at least one orthopedic episode involving the spine. Not ordering blood tests to evaluate blood levels of metabolic lab markers is not in keeping with current evidence that says bone strength is directly linked to vitamin D levels. Fractures are more likely to occur in people with low vitamin D. Supplementation can improve bone density especially during fracture healing when new bone must be put down to heal the old.
The information in this study should be viewed in light of the fact that other studies also show that when tested, more and more younger adults (50 to 70 years old) are also osteoporotic heading into spinal surgery. Since bone quality is an important factor in healing after spinal fusion, pre-operative testing for osteoporosis is advised for anyone at risk for this disease.
Treatment for osteoporosis may not change the immediate problem of a fragility fracture but it can benefit future health concerns. Surgeons may change the type and location of instrumentation used when screws or other hardware are needed. This change in surgical technique could help prevent loosening, nonunion of the fracture, and loss of deformity correction.
The authors conclude that there is a need for better education of surgeons regarding osteoporosis screening when treating elderly patients who need care for spinal fractures or who are undergoing spinal fusion for some other reason. Routine screening is advised when there has been a fragility fracture and when patients are at risk for osteoporosis. There is already some movement toward government regulation by the Center for Medicare and Medicaid Services to set quality standards for the preoperative screening, assessment, and treatment of osteoporosis in patients undergoing spinal fusion and who have pseudoarthrosis or fragility fractures.