A 62-year-old man with a history of chronic corticosteroid use for polymyalgia rheumatica sustains a Garden grade II intracapsular fracture of the femoral neck following a fall from standing height. He is medically optimized and fit for surgery. Which of the following factors is MOST likely to influence the choice between internal fixation and arthroplasty in this patient?

Explanation

## Pathophysiology of Femoral Neck Fracture Healing ### Vascular Anatomy and Fracture Displacement **Key Point:** The medial femoral circumflex artery (MFCA) is the primary blood supply to the femoral head. In intracapsular fractures, especially displaced ones, this artery is at high risk of disruption, leading to avascular necrosis (AVN). The critical decision point between internal fixation and arthroplasty hinges on: 1. **Degree of displacement** (Garden classification) 2. **Vascularity of the femoral head fragment** 3. **Patient age and functional demands** **High-Yield:** Garden grade I–II (undisplaced/minimally displaced) fractures have better blood supply preservation and higher union rates with internal fixation. Garden grade III–IV (displaced) fractures have disrupted blood supply and higher AVN risk, making arthroplasty preferable in elderly patients. ### Management Algorithm ```mermaid flowchart TD A[Intracapsular femoral neck fracture]:::outcome --> B{Garden grade & displacement?}:::decision B -->|Grade I-II: Undisplaced| C{Patient age?}:::decision B -->|Grade III-IV: Displaced| D{Patient age?}:::decision C -->|<65 years| E[Internal fixation with cannulated screws]:::action C -->|>65 years| F[Consider internal fixation if good vascularity]:::action D -->|<65 years| G[Internal fixation + close AVN monitoring]:::action D -->|>65 years| H[Arthroplasty: hemiarthroplasty or THA]:::action E --> I[Union expected, low AVN risk]:::outcome H --> J[Immediate mobilization, lower non-union risk]:::outcome ``` ### Why This Patient Requires Careful Assessment Although this patient is 62 years old (borderline), the **Garden grade II classification** is the decisive factor: - Grade II = minimally displaced, **better blood supply preservation** - MFCA disruption is less likely - Internal fixation with cannulated screws is appropriate if imaging confirms minimal displacement - Corticosteroid use increases osteoporosis risk but does NOT absolutely contraindicate fixation **Clinical Pearl:** The "Garden grade" is the single most important imaging variable. A Garden II fracture in a 62-year-old with good bone quality (despite steroids) is a candidate for internal fixation, whereas a Garden III–IV in the same patient would favor arthroplasty. ### Why Corticosteroid Use Does Not Determine the Choice While chronic corticosteroids impair fracture healing and increase osteoporosis: - They do NOT directly disrupt femoral head blood supply - The vascular anatomy (MFCA status) remains the primary determinant - Healing may be slower, but with appropriate fixation and protected weight-bearing, union is achievable **Warning:** Do not confuse "impaired healing" with "contraindication to fixation." Steroids increase healing time but do not eliminate the option of internal fixation in undisplaced fractures.