First and second year — the floor first, then every step
Name the site — intracapsular (femoral neck) or extracapsular (intertrochanteric, subtrochanteric) — and whether a neck fracture is displaced: that single distinction decides fixation versus replacement. When the radiograph is normal and the patient cannot bear weight, MRI.
Orient first
The femoral head's blood supply runs up the neck in the retinacular vessels; a DISPLACED intracapsular fracture disrupts it (avascular necrosis and non-union risk), which is why displaced neck fractures in older patients are usually replaced rather than fixed.
Extracapsular fractures bleed more but heal; the question for them is stability (the lesser trochanter and the lateral wall).
Occult fractures are common in osteoporotic bone. A normal radiograph with inability to bear weight is not a negative study.
Acquire the study
AP pelvis and a lateral (cross-table) view of the affected hip.
The manoeuvre
Trace the cortex of the neck on AP and lateral: a step in the superior or inferior cortex, a band of sclerosis (impaction) across the neck, or angulation of the trabecular lines.
Shenton's line and the neck–shaft angle compared with the other side.
Trochanteric region: lesser trochanter fragment, lateral wall, and extension below the lesser trochanter (subtrochanteric).
Lateral subtrochanteric cortex: focal thickening or "beaking" — the atypical femoral fracture of long-term bisphosphonate use.
Pubic rami and the acetabulum — the commonest alternative fractures when the hip is normal.
What confirms it
A cortical break, a trabecular impaction line or a T1 low-signal fracture line — not marrow oedema alone.
What licenses you to exclude it
A normal radiograph does not exclude a hip fracture when the patient cannot bear weight; say MRI is required.
The classic misread
Missing an impacted valgus neck fracture that looks almost normal on AP — check the lateral and the trabecular angle.
Stopping at a normal hip and missing a pubic ramus fracture.
Reporting the injury
Classification to use
Intracapsular (femoral neck): Garden I–IV — reported in practice as UNDISPLACED (I–II) or DISPLACED (III–IV); Pauwels angle for young patients. Extracapsular: intertrochanteric (AO/OTA 31A1–A3, stable versus unstable) and subtrochanteric.
Measurements — and how to take them
Neck–shaft angle compared with the other side (degrees); displacement in mm.
Pauwels angle in young patients: the angle of the fracture line to the horizontal on the AP view.
What to report
Site, displaced versus undisplaced, comminution of the posterior neck, lesser trochanter and lateral wall involvement, subtrochanteric extension.
Pathological (underlying lesion) or atypical features; pre-existing arthroplasty or fixation.
How to report it
X-ray: "Displaced subcapital fracture of the left femoral neck (Garden IV) with superior migration of the shaft."
MRI: "Linear low T1 signal traversing the full width of the right femoral neck from the superior to the inferior cortex with surrounding marrow oedema — undisplaced femoral neck fracture."
What not to report
Do not quote a Garden grade without also stating displaced / undisplaced — the binary is what the surgeon uses.
Do not report "no fracture" on radiographs in a patient who cannot bear weight without advising MRI.
Associated injuries to look for
Pubic rami and acetabular fractures, head injury from the fall, and in the young high-energy patient an ipsilateral femoral shaft fracture.
What changes management
Displaced intracapsular — arthroplasty in older patients; undisplaced — fixation.
Atypical or pathological fracture — a different implant and further work-up.
Reference values
Each value carries the caveat that keeps it from being misused. Normal limits and diagnostic criteria are kept apart on purpose: a disease cut-off read as a normal range is the more dangerous mistake.
Diagnostic criteria
Femoral neck (Garden) · Garden I–IV (undisplaced versus displaced bin)
I = incomplete / valgus-impacted. II = complete, undisplaced. III = complete, partially displaced. IV = complete, fully displaced. Modern practice often bins I–II (undisplaced) versus III–IV (displaced) because I versus II agreement is poor
Inter-observer agreement on I versus II is poor — that is why the displaced / undisplaced bin exists. State displacement and whether the calcar is shattered.
X-ray
See it on real cases
Direct links to Radiopaedia — the reference article and worked cases with their images. Each opens on Radiopaedia.