Hip fractures: Garden, the blood supply of the femoral head and treatment under NICE CG124

The anatomy that decides treatment

The hip capsule attaches to the intertrochanteric line in front but only halfway along the neck behind. Fractures inside it (subcapital and transcervical) behave very differently from those outside it (basicervical, trochanteric and subtrochanteric), because of the blood supply to the head.

• Medial femoral circumflex artery. Its deep branch runs behind the neck and gives the posterosuperior retinacular (lateral epiphyseal) arteries, which climb beneath the synovium along the neck to supply most of the weight-bearing head. A displaced intracapsular fracture tears them.
• Lateral femoral circumflex artery. Supplies the front of the neck and contributes little to the head in adults.
• Artery of the ligamentum teres. A branch of the obturator artery; small and variable in adults, and not enough to keep the head alive.
• Intraosseous supply. Metaphyseal vessels crossing from the neck, divided by any intracapsular fracture.

Classification

Pauwels classified intracapsular fractures by the angle of the fracture line to the horizontal: under 30° (type I), 30–50° (type II) and over 50° (type III). The more vertical the line, the more shear and the higher the risk of non-union, which matters most in young patients after high-energy injury.

Extracapsular fractures are trochanteric or subtrochanteric. The AO/OTA system divides trochanteric fractures into simple pertrochanteric (A1), multifragmentary pertrochanteric with an incompetent lateral wall (A2) and intertrochanteric, including reverse oblique, fractures (A3). Subtrochanteric fractures lie within about 5 cm below the lesser trochanter. A basicervical fracture is extracapsular in behaviour and is treated like a trochanteric fracture.

Before theatre

• A Hip Fracture Programme from admission. NICE asks for orthogeriatric, ward-based care that includes rapid optimisation for surgery, early identification of rehabilitation goals and continued orthogeriatric and multidisciplinary review.
• Analgesia. Paracetamol and opioids, with a nerve block (such as a fascia iliaca block) if they are not enough. NICE is explicit that nerve blocks are not a substitute for early surgery.
• Timing. Surgery on the day of, or the day after, admission. Delay is justified only by a correctable problem, such as uncorrected anaemia, fluid or electrolyte disturbance, anticoagulation, or an arrhythmia or heart failure that can be treated quickly.
• Anaesthesia. Spinal or general. In REGAIN (Neuman, NEJM 2021) spinal anaesthesia did not improve survival or recovery of walking at 60 days compared with general anaesthesia.

Intracapsular fractures

NICE CG124 offers replacement arthroplasty, either total hip replacement or hemiarthroplasty, for displaced intracapsular fractures. The 2023 update suggests considering total hip replacement rather than hemiarthroplasty for people who were able to walk independently out of doors with no more than the use of a stick, who have no condition or comorbidity that makes the procedure unsuitable, and who are expected to carry out activities of daily living independently beyond two years. The older wording about cognitive impairment was replaced by this emphasis on function.

• HEALTH (Bhandari, NEJM 2019): total hip arthroplasty did not reduce secondary procedures at 24 months compared with hemiarthroplasty. Function and quality of life were slightly better with total hip arthroplasty, and dislocation was commoner.
• Cement. NICE asks for cemented implants. In WHiTE 5 (Fernandez, NEJM 2022) cemented hemiarthroplasty gave better quality of life at four months than a modern uncemented design, with similar mortality and fewer periprosthetic fractures.
• Stem design. The 2023 update asks hospitals to use a single type of cemented femoral component for hemiarthroplasty, choosing between equivalent designs on cost, training and team familiarity.
• Approach. NICE suggests considering an anterolateral rather than a posterior approach for hemiarthroplasty.
• Bone cement implantation syndrome. Hypoxia, hypotension or cardiac arrest at cementation. The 2015 AAGBI/BOA/BGS safety guideline covers identifying high-risk patients, team briefing, careful cementing technique and close monitoring.

Extracapsular fractures

• Trochanteric fractures. NICE asks for extramedullary implants such as a sliding hip screw in preference to an intramedullary nail. The exception is the reverse oblique fracture involving the lesser trochanter, in which the screw would slide along the fracture line; it is nailed. An incompetent lateral wall also favours a nail, to prevent excessive collapse.
• Subtrochanteric fractures. NICE asks for an intramedullary nail. The proximal fragment is flexed by iliopsoas, abducted by the gluteal muscles and externally rotated, while the adductors pull the shaft medially; a load-sharing nail with a short lever arm resists these forces better than a plate.
• Tip–apex distance. The sum of the distances from the tip of the lag screw to the apex of the femoral head on the AP and lateral views, corrected for magnification. Baumgaertner (JBJS Am 1995) found that cut-out rose steeply above 25 mm.
• Atypical femoral fractures. A transverse, non-comminuted subtrochanteric or shaft fracture with lateral cortical thickening (beaking), linked to long-term bisphosphonate use. Image the other femur, nail the fracture and stop the bisphosphonate.
• Pathological fractures. Image the whole femur, biopsy if there is no known primary, and use a long nail or a long-stemmed arthroplasty to protect the bone.

After surgery

• Weight bearing. NICE asks surgeons to operate so that patients can bear full weight, without restriction, immediately after surgery.
• Mobilisation. A physiotherapy assessment and, unless medically or surgically contraindicated, mobilisation on the day after surgery; then mobilisation at least once a day with regular physiotherapy review.
• Bone health and falls. Assess bone health and falls risk before discharge, and start secondary fracture prevention.
• Audit. In England, Wales and Northern Ireland every hip fracture is recorded in the National Hip Fracture Database, which publishes each hospital’s performance against key indicators such as prompt surgery and orthogeriatric review.