A 72-year-old woman with osteoporosis falls on her right hip while getting out of bed. She presents with severe groin pain and inability to bear weight. What is the most common type of neck of femur fracture in elderly patients?

Explanation

## Classification of Neck of Femur Fractures Neck of femur (NOF) fractures are classified anatomically based on their location relative to the femoral head and neck. ### Anatomical Classification | Fracture Type | Location | Frequency | Blood Supply Risk | Prognosis | |---|---|---|---|---| | Subcapital | Just below femoral head | **Most common (~50–60%)** | Highest (intracapsular) | Poorest | | Transcervical | Mid-cervical region | Less common | High (intracapsular) | Poor | | Basicervical | Base of femoral neck | Least common | Moderate (borderline) | Better | | Intertrochanteric | Between greater & lesser trochanters | Common (extracapsular) | Low | Best | **Key Point:** **Subcapital fractures** are the most common type of femoral neck fracture in elderly patients with osteoporosis, accounting for approximately **50–60% of all intracapsular femoral neck fractures**. This is consistently cited in standard orthopedic references including Bailey & Love's Short Practice of Surgery, Campbell's Operative Orthopaedics, and Rockwood & Green's Fractures in Adults. **High-Yield:** The subcapital fracture occurs at the junction of the femoral head and neck — the site most vulnerable to the bending and shear forces generated during a fall in an osteoporotic elderly patient. This location carries the highest risk of: - Avascular necrosis (AVN) — due to disruption of the retinacular vessels (branches of the medial femoral circumflex artery) - Non-union — especially in displaced (Garden III/IV) fractures - Femoral head collapse requiring hemiarthroplasty or total hip replacement **Clinical Pearl:** The Garden classification (I–IV) is specifically applied to **subcapital** fractures. Garden I & II (undisplaced) are managed with internal fixation (cannulated screws), while Garden III & IV (displaced) in elderly patients are managed with hemiarthroplasty (Austin Moore / Thompson prosthesis) or total hip replacement. **Why Subcapital is Most Common:** 1. The subcapital region is the narrowest and most mechanically stressed part of the femoral neck 2. Osteoporosis preferentially weakens the subcapital trabecular bone 3. Low-energy falls (ground-level) in elderly women generate forces concentrated at the subcapital region **Mnemonic:** **S**ubcapital = **S**uperior frequency + **S**everest AVN risk. [cite: Bailey & Love's Short Practice of Surgery, 27th Ed., Ch. 25; Campbell's Operative Orthopaedics, 13th Ed.; Rockwood & Green's Fractures in Adults, 8th Ed., Ch. 50]