A 28-year-old woman with a history of type 2 diabetes mellitus presents 10 weeks after a simple fracture of the distal radius (Colles' fracture) treated with closed reduction and plaster immobilization. X-rays show minimal callus formation and no bridging callus is visible. The patient reports persistent pain and swelling at the fracture site. What is the most appropriate next step in management?

Explanation

## Clinical Context The patient is at 10 weeks post-fracture with **delayed callus formation and absence of bridging callus**, which is abnormal. In a typical Colles' fracture, bridging callus should be visible by 6–8 weeks. The presence of diabetes mellitus is a significant risk factor for impaired fracture healing due to: - Impaired angiogenesis and neovascularization - Reduced growth factor signaling (TGF-β, VEGF) - Altered collagen synthesis and mineralization - Increased infection risk ## Key Point: **This fracture shows evidence of delayed union.** The next step is NOT to continue passive immobilization or remove the cast prematurely, but to **investigate the cause and consider biological augmentation** (bone morphogenetic proteins, platelet-rich plasma, or bone grafting) to stimulate healing. ## Delayed Union vs. Non-Union | Feature | Delayed Union | Non-Union | |---------|---------------|----------| | **Timeline** | Healing progresses but slower than expected (>8–12 weeks) | No healing progression after 6+ months | | **Callus** | Minimal or absent callus | Absent or sclerotic callus; pseudarthrosis | | **X-ray** | No bridging callus at expected time | No bridging; gap may widen | | **Management** | Biological augmentation, optimize factors | ORIF, bone graft, biological agents | | **Prognosis** | Good with intervention | Requires surgical intervention | ## High-Yield: **Risk factors for delayed union in fractures:** - **Metabolic:** Diabetes, malnutrition, vitamin D deficiency, osteoporosis - **Local:** Infection, soft tissue injury, poor blood supply, comminution - **Systemic:** Smoking, chronic kidney disease, immunosuppression - **Iatrogenic:** Excessive immobilization, infection, poor reduction ## Clinical Pearl: In a diabetic patient with delayed callus formation at 10 weeks, the fracture biology is compromised. Simply removing the cast risks loss of reduction and displacement. ORIF without addressing the underlying biological deficit may also fail. **Biological augmentation with growth factors or bone graft is the evidence-based next step** to enhance healing before considering surgical fixation. ## Mnemonic: **DELAY** — Diabetes Enhances LAck of callus; Yield to biology-first approach (growth factors, bone graft, optimize nutrition, glucose control).