Fracture

• Overview:

  • The femoral neck is the weakest part of the femur
  • Neck of femur (NOF) fractures typically occur in the elderly - most commonly in women
  • Can occur in young patients as a result of high energy trauma
  • NOF fracture carries significant mortality with 1/10 patient dying in the first month, and 1/3 within the first year
• The hip joint is stabilised by a capsule, which is formed of three ligaments: the iliofemoral, ischiofemoral and pubofemoral ligaments.

  The femoral head receives blood supply from three arterial sources:

  • Nutrient arteries inside the bone
  • Ligamentum teres
  • The femoral circumflex arteries: encircle the femoral neck on top of the capsule
• Causes:

  • Majority of NOF fractures in older patients because of low-energy trauma e.g. fall from standing height
  • High energy trauma
  • Pathological fracture e.g. tumour or infection
  • Reduced bone mineral density - osteopenia and osteoporosis - long term steroid use, alcohol or malnutrition
  • Stress fracture - rare
• Fractures can be classified by anatomical location:

  • Intracapsular - proximal to intertrochanteric line
  • Extracapsular - below the intertrochanteric line
• Intracapsular:

  • Proximal to intertrochanteric line
  • Involves damage to the joint capsule - blood supply from the femoral circumflex arteries and nutrient arteries inside the bone are disrupted
  • Only intact artery supplying the femoral head is the artery within the ligamentum teres which is not enough to keep the femoral head viable
  • Intracapsular fractures have a high risk of avascular necrosis of the femoral head and non-union of the fracture
• Extracapsular fractures:

  • Below the intertrochanteric line
  • Inter-tronchanteric = between the greater and less trochanters
  • Sub-tronchanteric = below the lesser trochanter (within 5cm)
  • Joint capsule is not damaged and blood supply to the fracture is sufficient
  • Better fracture healing and improved prognosis
• Risk factors:

  • Age (≥65 years in women and ≥75 years in men)
  • History and risk factors of osteoporosis including menopause, amenorrhoea, smoking, excessive alcohol, corticosteroid use
  • Previous fragility fracture
  • History of falls
  • Poor nutrition
  • Low BMI
  • Dementia
  • Visual impairment: which increases the risk of falls and subsequently fractures
  • History of tumours
• Typical symptoms:

  • Pain - hip, groin or knee
  • Unable to weight bear
  • Decreased or painful mobility of the affected hip
• Areas to cover in history:

  • PMH - cancer, bone tumours, fragility fractures, cognitive impairment
  • Drug history - medications that may cause osteoporosis or have contributed to the fall e.g. sedatives
  • Social history - home situation
  • Frailty score
• Clinical exam:

  • Avoid excessive movement of the hip
  • Full neurovascular examination of the limb to identify any neurological injury
  • Affected leg - shorted, externally rotated and abducted
  • Palpation of hip is painful
  • Unable to perform straight leg raise
  • Log roll test - pain on gentle internal and external rotation
  • Bruising and swelling in and around hip
• Bedside investigations:

  • ECG - look for any arrhythmias or cardiac event that may have precipitated a fall
• Lab investigations:

  • Baseline - FBC, U&Es, coagulation screen
  • Creatinine kinase if fall long lie
  • Urinalysis - UTIs or hypoglycaemia
  • Group and save
• Imaging:

  • X-rays first line: AP and lateral views of the affected hip and AP pelvis
  • Full length femoral x-ray if pathological fracture suspected
  • MRI is gold standard
  • CT can be done if high clinical suspicion and x-rays are normal
• Initial management:

  • A to E approach
  • Analgesia - paracetamol, opioids and iliofascial/femoral nerve block NSAIDS should be avoided
  • IV access for fluid resuscitation, blood transfusion and medications
• Principles of surgical management:

  • Urgent reduction and internal fixation followed by early mobilisation
  • Should undergo surgery within 36 hours of admission
  • Early mobilisation to prevent VTE, pressure ulcers and bronchopneumonia
• Intracapsular fracture management:

  • Young (<65) or physiologically fit patients = femoral head rescued with cannulated screws or dynamic hip screw
  • Dynamic hip screw permits organised collapse of the fracture when the patient weight bears - improves fracture healing and union
  • Older patients = total or hemi hip arthroplasty - removal of the femoral head and insertion of a prosthetic replacement
• Cannulated screws involve a set of screws being driven into the femoral head across the fracture which stabilises the fracture. 
• A dynamic hip screw is a dynamic plate screwed across the fracture line into the femoral head.
• Extracapsular fracture management:

  • Internal fixation with dynamic hip screw or trochanteric femoral intramedullary nailing with screws entering the femoral head
• Indications for non-operative management include:

  • Patients that are too unwell to undergo surgery
  • Short life expectancy
  • Delayed presentation or diagnosis of fracture with signs of healing
  • Immobile patients
  • Patients who decline surgery
  • Can be managed with casts, splits and traction. Periodic X-rays needed.
• Post-operative management:

  • Analgesia
  • Rehabilitation with early mobilisation
  • Falls risk assessment
  • Axial bone densitometry - assess for osteoporosis
  • Antibiotic prophylaxis
  • VTE prophylaxis - mechanical VTE prophylaxis with intermittent pneumatic compression on admission. Consider pharmacological VTE prophylaxis when the risk of VTE outweighs risk of bleeding
• Complications of non-operative conservative management include:

  • Fracture displacement
  • Non-union or mal union
  • Avascular necrosis of femoral head
  • Venous thromboembolism
  • Pressure sores
  • Infection: pneumonia and urinary tract infections
  • Death
• Medical complications of surgical management include:

  • Surgical site infection
  • Protein-caloric malnutrition
  • Anaemia
  • Venous thromboembolism
  • Post-operative delirium
  • Bleeding
  • Fat embolism
• Complications related to dynamic hip screws and cannulated screws include:

  • Non-union and femoral head avascular necrosis
  • Soft tissue irritation caused by a lag screw pressing into soft tissue
  • Screw cut out (due to the brittleness of osteoporotic bone)
• Complications related to total/hemiarthroplasty include:

  • Peri-prosthetic fracture, prosthetic loosening or dislocation of the prosthesis
  • Acetabular wear
  • Bone cement implantation syndrome
  • Femoral shaft fracture
• XR interpretation:

  • Shenton's line should be a continuous line from the superior pubic ramus down to the lesser trochanter
  • Loss of Shenton's line suggests a NOF fracture