Fractured Neck of Femur

#NOF is a major cause of orthopaedic admission in the UK. The most important distinction is the relationship of the fracture line to the hip joint capsule. Intracapsular fractures (within the capsule) risk damaging the medial circumflex femoral artery, which provides the primary blood supply to the femoral head. If this supply is disrupted, avascular necrosis (AVN) occurs. Extracapsular fractures (trochanteric or subtrochanteric) have a better blood supply but require stable fixation. Clinical presentation is a shortened and externally rotated leg after a fall. NICE (NG124) guidelines mandate surgery within 36 hours of admission, early mobilization (day after surgery), and Co-managed orthogeriatric care. Pain management should include fascia iliaca compartment blocks to reduce reliance on systemic opioids.

The hip joint is a ball-and-socket joint. The femoral head's blood supply comes mainly from the medial circumflex femoral artery forming an extracapsular arterial ring, with retinacular vessels piercing the capsule to reach the head. In an intracapsular fracture, these retinacular vessels are often torn. The ligamentum teres provides only a negligible blood supply in adults. Without blood, the femoral head undergoes osteocyte death within hours. Extracapsular fractures occur distal to the capsule in the highly vascular cancellous bone of the trochanteric region, meaning AVN is rare, but the hip is subject to high mechanical stresses, requiring robust hardware for fixation.

Patients are typically elderly and female, presenting after a fall. They are unable to weight bear. On examination, the leg is shortened and externally rotated due to the pull of the iliopsoas and other rotators. In 'impacted' fractures, the patient might still be able to walk, but this is rare. High mortality (approx. 10% at 1 month, 30% at 1 year) is often due to complications of immobility: pneumonia, VTE, and pressure sores. Pre-operative assessment must include an AMTS (Abbreviated Mental Test Score) and screening for secondary causes of the fall (e.g., syncope, UTI).

- Bedside: ECG (pre-op and to check for cardiac causes of fall); Urine dip.
- Bloods: FBC, U&E, Coagulation screen, Group and Save (crossmatch 2 units), Bone profile.
- Imaging: AP and lateral X-rays of the affected hip/pelvis. 'Shenton's line' disruption suggests fracture. If X-rays are negative but clinical suspicion is high, MRI or CT Hip is gold standard within 24 hours.

Initial: Analgesia (Fascia Iliaca Block), IV fluids, VTE prophylaxis. Surgical: 1. Intracapsular Undisplaced (Garden I-II): Internal fixation (cannulated screws). 2. Intracapsular Displaced (Garden III-IV): Total Hip Replacement (if fit, previously mobile, and cognitively intact) or Hemiarthroplasty. 3. Extracapsular (Intertrochanteric): Dynamic Hip Screw (DHS). 4. Subtrochanteric: Intramedullary (IM) nail. Post-op: Full weight-bearing and mobilization within 24 hours. Start bone protection (Bisphosphonates/Vitamin D) the following month.