Reverse oblique (intertrochanteric) fracture

AO/OTA 31A3

Unstable · nail, not DHS

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The fracture line runs from distal-lateral to proximal-medial, the opposite of a standard pertrochanteric fracture. Sliding along a hip screw would push the shaft medially, so a sliding hip screw fails.

Mechanism

Falls in the elderly; also as a subtrochanteric extension of higher-energy injuries.

Clinical findings

As for other hip fractures: short, externally rotated leg, unable to bear weight.

Imaging

AP pelvis and AP of the hip.
Axial view (cross-table lateral).
Full-length femur: the fracture runs down into the subtrochanteric region.

Look at the direction of the main fracture line on the AP view and at extension into the subtrochanteric region.

Classification

31A3.1: Simple oblique (reverse oblique).
31A3.2: Simple transverse.
31A3.3: Wedge or multifragmentary.

Types shown in 3D

31A3.1: Simple reverse oblique: from distal-lateral to proximal-medial.
31A3.2: Simple transverse across the trochanteric region.
31A3.3: Wedge or multifragmentary (here with a lesser trochanter fragment).

Treatment

Treatment of choice: Long or short cephalomedullary nail after accurate closed (or minimally open) reduction. Correct varus and the medial displacement of the shaft before reaming.
Avoid: A sliding hip screw alone: the shaft medialises and the fixation fails.

Aftercare

Weight bearing as tolerated after a well-reduced nail. Watch for delayed union in the subtrochanteric extension.

Complications

Malreduction in varus
Non-union
Implant failure