Endo Paget Bisphosphonate Pre Osteotomy Bowing

---
name: endo-paget-bisphosphonate-pre-osteotomy-bowing
description: Recommends administering a potent bisphosphonate prior to elective osteotomy for severe lower‑extremity bowing in Paget’s disease that causes impaired ambulation or severe joint pain. Triggered when planning surgical correction of a lower‑extremity deformity in a patient diagnosed with Paget’s disease.
---

# Give bisphosphonate before osteotomy for severe bowing

## STEP 1 — Gather Information
Confirm Paget’s disease diagnosis (radiographs ± bone scan), assess severity of lower‑extremity bowing, ambulation status, joint pain, and planned elective osteotomy; check serum creatinine/eGFR, vitamin D level, and calcium to rule out contraindications.

## STEP 2 — Rule In / Rule Out
If the patient has severe bowing requiring osteotomy **and** reports impaired ambulation or severe joint pain, proceed; otherwise, consider non‑surgical management or delay intervention.

## STEP 3 — Classify or Stratify
Stratify by renal function: eGFR ≥35 mL/min permits standard IV zoledronate; eGFR <35 mL/min requires dose adjustment or oral bisphosphonate; also assess vitamin D deficiency and correct before therapy.

## STEP 4 — Decide
Administer a single 5‑mg IV zoledronate (or equivalent potent bisphosphonate) 1–2 months before osteotomy; if IV contraindicated, give oral alendronate 40 mg daily for 6 months completing prior to surgery, with calcium and vitamin D supplementation.

## Clinical Guardrails / Mimics / Pitfalls
Do not give zoledronate if eGFR <35 mL/min without adjustment; avoid in untreated vitamin D deficiency; monitor for acute phase reaction (fever, myalgia); do not delay surgery beyond the optimal window after bisphosphonate; ensure adequate calcium/vitamin D; not indicated for asymptomatic mild bowing.

## Concrete Clinical Example
A 62‑year‑old man with tibial Paget’s disease presents with 15° varus bowing, walking pain, and limited ambulation; planned tibial osteotomy. eGFR 55 mL/min, vitamin D sufficient. He receives zoledronate 5 mg IV two weeks pre‑op; postoperative alignment improved and pain decreased.

**Source:** Paget’s Disease of Bone: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2014, doi:10.1210/jc.2014-2910