Anabolic Agents for Osteoporosis Prior to Back Surgery
Teriparatide is the recommended anabolic agent for empiric preoperative therapy in patients with osteoporosis undergoing spinal instrumentation, with Grade B evidence demonstrating reduced screw loosening (7% vs 13% with bisphosphonates), earlier fusion (8 months vs 10 months), and higher fusion rates (82% vs 68%). 1, 2
Primary Recommendation: Teriparatide
The Congress of Neurological Surgeons (2021) provides the strongest guideline evidence supporting preoperative teriparatide specifically for spine surgery patients with osteoporosis 1. This represents a Grade B recommendation—the highest level of evidence available for this clinical scenario.
Key benefits of preoperative teriparatide include:
- Decreased postoperative adverse events, particularly screw loosening and instrumentation failure 1
- Earlier and more robust fusion compared to bisphosphonates or no treatment 1, 2
- Increased bone mineral density in the perioperative period 1, 2
- Reduced risk of proximal junctional failure in instrumented spine surgery 1
Alternative Anabolic Agents
While teriparatide has the strongest spine surgery-specific evidence, two other anabolic agents may be considered:
Abaloparatide:
- Appropriate alternative for patients at very high fracture risk 2
- Reduces vertebral fractures by 86% and nonvertebral fractures by 43% at 18 months 2
- Caveat: Lacks specific spine surgery outcome data, making it a second-choice option when teriparatide is unavailable or not tolerated 2, 3
Romosozumab:
- Should be used with caution and only when other agents are not tolerated 2
- Associated with cardiovascular concerns that limit its use 2
- Reduces vertebral fractures by 13 per 1000 patients 2
- Critical limitation: No published data on perioperative spine surgery outcomes 4
Patient Selection Criteria
Anabolic agents should be initiated preoperatively when patients meet the following criteria:
- Confirmed osteoporosis (DEXA T-score < -2.5) AND undergoing spinal instrumentation 1
- BMD T-score ≤ -3.5 (severe osteoporosis) 2
- Recent fracture within past 12 months 2
- FRAX 10-year risk: major osteoporotic fracture ≥30% OR hip fracture ≥4.5% 2
- Multiple prior osteoporotic fractures 2
- High-dose glucocorticoid use with osteoporosis 2, 5
Absolute Contraindications
Do not use any anabolic agent in patients with:
- Prior radiation therapy involving the skeleton 2
- Bone metastases or skeletal malignancies 2
- Paget's disease of bone 2
- Open epiphyses 2
- History of osteosarcoma or conditions predisposing to osteosarcoma 6
Critical Treatment Considerations
Preoperative assessment requirements:
- DEXA scan (T-score < -2.5 indicates osteoporosis) 1
- CT scan Hounsfield units < 97.9 predict increased postoperative complications 1
- Serum vitamin D3 level (< 20 ng/mL associated with poor outcomes) 1
Mandatory sequential therapy:
- Anabolic agents must be followed by antiresorptive therapy (bisphosphonates or denosumab) immediately after completion 2
- Discontinuing anabolic agents without follow-up antiresorptive therapy results in rapid bone loss and increased fracture risk within 12-18 months 2
Why Not Bisphosphonates Alone?
The Congress of Neurological Surgeons found insufficient evidence to support bisphosphonates alone for preoperative osteoporosis treatment in spine surgery patients 1. While bisphosphonates remain first-line therapy for general osteoporosis management 6, 7, the perioperative spine surgery context specifically favors anabolic agents due to their superior fusion outcomes and reduced hardware complications 1, 2, 4.
Timing and Duration
Teriparatide should be initiated preoperatively with treatment duration of 11-21 months demonstrating optimal efficacy 5. The anabolic effects on bone formation occur rapidly, making preoperative initiation valuable even with shorter lead times before surgery 8, 4.
Common pitfall: Surgeons often defer osteoporosis management to other specialists, but preoperative optimization is critical for surgical success in this population 1.