When should bisphosphonates (bone resorption inhibitors) be discontinued prior to hip replacement surgery?

Bisphosphonate Management Prior to Hip Replacement Surgery

Bisphosphonates should be discontinued at least 2 months prior to hip replacement surgery to reduce the risk of osteonecrosis of the jaw (ONJ) and potential complications during the perioperative period. 1

Risk Assessment and Rationale

Bisphosphonates accumulate in bone tissue and can interfere with bone remodeling processes, which is particularly important during surgical recovery. The management of bisphosphonates before hip replacement requires careful consideration of several factors:

Osteonecrosis of the Jaw Risk

• Bisphosphonates have been associated with ONJ, with risk increasing with:
  • Longer duration of therapy 1
  • IV formulations (higher risk than oral) 1
  • Concurrent use of chemotherapy or corticosteroids 1

Fracture Risk Considerations

• Discontinuing bisphosphonates after 2+ years of compliant use may increase hip fracture risk 2
• However, patients with higher compliance (≥80%) or longer duration (≥3 years) of therapy show less increased risk upon discontinuation 2
• Bisphosphonates create a reservoir in bone that continues to provide some residual anti-fracture effect for 1-2 years after discontinuation 3

Surgical Outcomes

• Recent evidence (2023) suggests that preoperative bisphosphonate use is associated with higher rates of:
  • Intraoperative and postoperative periprosthetic fractures (OR: 1.39)
  • Revisions within one year (OR: 1.14) 4

Recommended Protocol

Timing of Discontinuation

1. Standard recommendation: Discontinue bisphosphonates 2 months prior to hip replacement surgery 1
2. Duration considerations:
   • For patients on bisphosphonates <3 years: Higher priority to discontinue
   • For patients on bisphosphonates >5 years: Critical to discontinue due to increased long-term risk of atypical fractures 5

Preoperative Assessment

1. Comprehensive dental examination before surgery to identify and address any dental issues 1
2. Measure serum calcium, vitamin D, and renal function 5, 1
3. Assess bone mineral density to establish baseline 1

Perioperative Management

1. Ensure adequate calcium and vitamin D supplementation during the perioperative period 5
2. Consider antibiotic prophylaxis for the surgical procedure to minimize infection risk 1
3. Use minimally invasive surgical techniques when possible 1

Postoperative Considerations

1. Monitor for signs of ONJ: pain, swelling, or exposed bone in the jaw 1
2. For patients at high risk of osteoporotic fractures, consider restarting bisphosphonate therapy 3-6 months after successful surgery and healing 6
3. Bisphosphonate therapy post-THA may decrease periprosthetic bone loss and increase implant longevity 4

Special Considerations

High Fracture Risk Patients

For patients at very high risk of fracture (T-score ≤-3.5, history of fracture while on treatment, or high-dose glucocorticoid use):

• Consider shorter discontinuation period (4-6 weeks)
• Discuss with both orthopedic surgeon and prescribing physician to balance risks 1

Long-Term Bisphosphonate Users

For patients who have been on bisphosphonates for >5 years:

• The American College of Physicians recommends considering stopping bisphosphonate treatment after 5 years due to increased risk of long-term harms 5, 1
• These patients may benefit from a drug holiday regardless of planned surgery 3

Resuming Therapy

After successful hip replacement and healing:

• Reassess fracture risk
• Consider that bisphosphonate use post-THA may be beneficial for implant longevity 6, 4
• For patients who had been on therapy >5 years before surgery, consider alternative osteoporosis treatments 5

By following this protocol, clinicians can minimize the risks associated with bisphosphonate therapy while optimizing outcomes for patients undergoing hip replacement surgery.