No Need to Hold Fosamax Before Knee Surgery
Patients do not need to discontinue alendronate (Fosamax) before knee surgery. The available evidence addresses perioperative management of antirheumatic medications and anticoagulants, but bisphosphonates like alendronate are not included in any perioperative withholding recommendations.
Why Fosamax Does Not Require Perioperative Discontinuation
Not Addressed in Surgical Guidelines
The 2022 ACR/AAHKS perioperative management guidelines specifically address DMARDs, biologics, JAK inhibitors, and immunosuppressive agents for patients with rheumatic diseases undergoing total hip or knee arthroplasty, but bisphosphonates are notably absent from these recommendations 1, 2, 1.
These guidelines focus on medications that affect infection risk through immunosuppression, which is not a mechanism of action for bisphosphonates 1.
Mechanism Does Not Warrant Holding
Alendronate works by inhibiting osteoclast-mediated bone resorption and does not cause immunosuppression, impair wound healing, or increase surgical bleeding risk 3.
The FDA labeling for Fosamax contains extensive warnings about gastrointestinal adverse reactions, hypocalcemia, osteonecrosis of the jaw, and atypical femoral fractures, but includes no warnings or precautions regarding perioperative use or surgical procedures 3.
Evidence Supports Continuation
Research demonstrates that alendronate may actually reduce periprosthetic bone loss after total knee arthroplasty, with patients maintaining distal femoral BMD values close to baseline when treated with 10 mg alendronate daily 4.
While one study showed no benefit of once-weekly alendronate on implant migration with uncemented fixation 5, this does not suggest harm or a need for discontinuation.
Special Considerations
Long-term Users
For patients who have been on alendronate for many years (>5 years), the FLEX trial data suggest that discontinuation may be considered based on fracture risk stratification, but this is a long-term treatment duration decision, not a perioperative consideration 6.
The decision to continue or stop alendronate after 5+ years should be based on ongoing fracture risk assessment (BMD, prior fractures, FRAX scores), not on upcoming surgery 7, 8, 9.
Atypical Femoral Fracture Concerns
If a patient has sustained an atypical femoral fracture while on long-term alendronate therapy and requires surgical nailing, discontinuation of alendronate and administration of bone-forming agents after surgery may promote fracture union 10.
This specific scenario (mean union time of 4.5 months with discontinuation versus 23.5 months with continuation) represents a unique clinical situation distinct from routine knee surgery 10.
Osteonecrosis of the Jaw Risk
The FDA label identifies invasive dental procedures as a known risk factor for osteonecrosis of the jaw in bisphosphonate users 3.
However, knee surgery is not an invasive dental procedure and does not carry this specific risk, so this warning does not apply to orthopedic surgery.
Practical Management
Continue Current Regimen
Patients should continue their usual weekly alendronate dosing schedule (70 mg once weekly) through the perioperative period 3.
Ensure patients maintain adequate calcium and vitamin D supplementation perioperatively 3.
Postoperative Considerations
Resume normal oral intake and upright positioning as soon as medically appropriate after surgery to allow proper alendronate administration (must be taken with 6-8 ounces of water, at least 30 minutes before first food/drink, with patient remaining upright for at least 30 minutes) 3.
If a patient cannot comply with proper dosing instructions due to postoperative limitations (inability to sit upright for 30 minutes, NPO status), temporarily hold the dose until they can safely take it per labeled instructions 3.
Common Pitfalls to Avoid
Do not confuse bisphosphonates with immunosuppressive antirheumatic medications that do require perioperative withholding 1, 2, 1.
Do not extrapolate anticoagulation management principles to bisphosphonates—these are entirely different drug classes with different perioperative considerations 11.
Do not discontinue alendronate based on theoretical concerns about bone healing or surgical outcomes when no evidence supports this practice 4, 5, 12.