Bone Health Optimisation

A great deal of spinal surgery relies on the bone holding metalwork or fusing solidly. Screws gain their grip from the density and quality of the bone they sit in; a fusion depends on the bone knitting across a segment. When bone is weak — through osteoporosis or low bone density — that grip is poorer, the risk of screws loosening or pulling out is higher, fusions are more likely to be slow or incomplete, and specific problems such as the vertebra above a fusion collapsing or the construct failing become more common. This is why, before planning fusion surgery in particular, I pay close attention to bone health rather than treating it as an afterthought.

Assessing bone health before surgery uses several tools. A DEXA scan measures bone density directly; the CT scans I often already have can give a measure of bone quality (Hounsfield units) opportunistically; and risk-assessment tools help identify who is at risk of fragility fractures. Blood tests can check for treatable contributors such as vitamin D deficiency. Where this assessment shows osteoporosis or significantly low bone density, it changes the plan — both in how I approach the surgery technically and in whether treatment to strengthen the bone should come first. Identifying this is my responsibility; the detailed diagnosis and treatment of osteoporosis is led by bone-health specialists.

Where bone is weak, optimising it before surgery can genuinely improve the situation, and this is done with the metabolic bone team. Measures range from correcting vitamin D and calcium and general bone-healthy advice, through to specific osteoporosis medications. Importantly, some treatments — particularly the "anabolic" (bone-building) agents such as teriparatide — have been shown to improve fusion rates in spine surgery, which is why, for higher-risk patients, treating the bone before or around the time of surgery can be worthwhile. The choice and prescribing of these medicines belongs to the GP, endocrinologist or metabolic bone specialist; my role is to flag the need and coordinate the timing with surgery.

The evidence is clear that bone health matters in spine surgery. Reviews of bone health optimisation in spine surgery set out screen-and-treat pathways and recommend an anabolic-first approach for high-risk patients; cohort studies show that osteoporosis-related complications after lumbar fusion rise with worsening bone status, and that low CT bone density predicts problems such as proximal junctional failure. A network meta-analysis found that teriparatide significantly increased fusion rates, and quality-improvement studies show that a dedicated bone-health pathway markedly increases appropriate screening and treatment. This evidence base is why I treat bone health as an integral part of surgical planning.

Where bone health is a concern, I arrange assessment and, with the metabolic bone team, any treatment needed — sometimes before proceeding with surgery, sometimes alongside it, depending on the situation. This may add a period of preparation, but it improves the chances of a fusion holding and healing well. The bone-health treatment itself is guided by the relevant specialists over the longer term.

• —Anderson PA, et al. Bone health optimization in spine surgery. Spine 2023. (PMID 36917718)
• —Anderson PA, et al. Preoperative bone health assessment and optimization in spine surgery. Neurosurg Focus 2020. (PMID 32738805)
• —Efficacy and safety of anti-osteoporotic drugs for spinal fusion surgery: network meta-analysis. 2023. (PMID 37969460)
• —Effect of bone health optimization on osteoporosis screening and treatment before thoracolumbar fusion. 2022. (PMID 35290252)
• —Incidence of osteoporosis-related complications following posterior lumbar fusion. 2018. (PMID 30202709)
• —Lower Hounsfield units and severe multifidus sarcopenia as predictors of proximal junctional kyphosis and failure following thoracolumbar fusion. 2023. (PMID 36692154)