Scotland ST1 Orthopaedic National Selection Preparation

Overview

Neck of Femur #'s will be one of the commonest presentations on an on call. Every unit has there own approach and some even have a set proforma. For the interview it would be beneficial to understand how to assess, initiate management and then how to work these patients up for theatre. Knowing the different surgical options for different patients/fractures is also important. 

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Classification

• Intracapsular: fracture line proximal to the capsule attachment.

  • High risk of disrupting the femoral head’s retrograde blood supply (via the medial femoral circumflex artery) → risk of avascular necrosis (AVN) and non-union.

  • Classified by Garden (I–IV, depending on displacement).

• Extracapsular: fracture line outside the capsule.

  • Lower risk of AVN as the blood supply is preserved.

  • Subdivided into intertrochanteric and subtrochanteric.

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TIP: In the IV, the main thing you need to identify on the imaging is if it's displaced/undisplaced or intracapsular vs extracapsular. In the absolute worst case scenario, if you can't see the fracture (which is probably unlikely), you can try and save yourself and ask for a CT scan. Asking for a CT when we aren't 100% sure if there is a fracture is common in the trauma meetings, but for the purpose of the IV it's likely to be obvious. 

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Clinical Features

• Elderly patient, usually post fall.

• Pain in the hip/groin and inability to weight bear.

• Leg is typically shortened, externally rotated, and abducted.

• Must assess for concurrent injuries, especially head trauma in falls.

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Investigations

• X-rays: AP pelvis and lateral hip.

• CT or MRI if X-ray is inconclusive.

• Routine bloods, group and save, ECG, and pre-operative workup.

• Always assess neurovascular status of the limb.

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Management

Initial (ATLS principles + optimisation)

• Analgesia (including femoral nerve block if available).

• IV fluids, oxygen, monitoring.

• Pressure area care, DVT prophylaxis.

• Fascia Iliaca Compartment Block --> You should know what nerves this is targeting. 

Surgical

• Intracapsular undisplaced (Garden I–II):

  • Internal fixation (multiple cannulated screws or dynamic hip screw).

• Intracapsular displaced (Garden III–IV):

  • Arthroplasty preferred in elderly:

    • Hemiarthroplasty – if reduced mobility or significant comorbidities.

    • Total hip replacement – if independent walker, cognitively intact, minimal comorbidities.

• Extracapsular intertrochanteric:

  • Dynamic hip screw.

• Extracapsular subtrochanteric or unstable:

  • Intramedullary nail.

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NICE Guidance

• Timing: Perform surgery on the day of, or the day after admission (ideally within 36 hours), unless the patient is medically unfit.

• Note: The reason the NICE guideline of aim to operate within 36hours is important is because it's highly likely that in your prioritisation station there will be a NOF. If the NOF has been waiting for 6 hours versus 36hours then it does influence decision making (or at least if you mention it it shows that you are aware.)

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​​​Anatomy​

Blood Supply to the Femoral Neck 

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This is a common interview question and generally most candidates know the answer. However, there are some salient points that are missed and for an entry level question, being slick is important. 

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The vascular supply to the femoral head and neck is mainly from the medial femoral circumflex artery (MFCA), a branch of the profunda femoris. Its posterior retinacular vessels run within the synovial folds along the femoral neck and provide the dominant retrograde supply to the femoral head (flowing from the base of the neck towards the epiphysis). The lateral femoral circumflex artery (LFCA) contributes anterior retinacular vessels, but these are less significant. In children, the artery of the ligamentum teres (from the obturator) provides an additional supply, which diminishes with age but can persist variably into adulthood. A minor contribution may also come from the inferior gluteal artery. Because this retrograde blood flow is end-arterial and intracapsular, it is highly vulnerable to disruption by displaced intracapsular neck of femur fractures, leading to an increased risk of avascular necrosis (AVN) and non-union.

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Some Possible Questions to Consider:

• Blood supply to femoral neck 

• which operation to choose based upon Xray

• Approach to the hip joints (covered in surgical approaches section)

• Post-operative considerations?

• Role of Fascia Ilia block and relevant anatomy.

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All Questions and more are discussed in the Question Bank section of the website.