Subtrochanteric

Subtrochanteric refers to the region of the femur located just below the lesser trochanter, extending into the proximal shaft. The exact boundaries vary among sources, but the region is defined as the segment beneath the trochanteric area and above the proximal shaft, typically within a few centimeters of the lesser trochanter.

The subtrochanteric region has distinctive biomechanics. It experiences high bending and torsional stresses due to the pull of surrounding muscles, including the gluteal group and hip adductors. The bone is thick-walled cortex in this area, yet fractures here can be technically challenging because of the forces acting on the proximal femur and the tendency for short, comminuted fragments.

Fractures of the subtrochanteric region account for a minority of proximal femur fractures, but they are clinically important. They can result from high-energy trauma in younger patients or from osteoporosis and metastatic disease in older adults. Fracture patterns are often transverse or short oblique and may be unstable, with a risk of malalignment or nonunion if not adequately stabilized.

Diagnosis relies on radiographic imaging. Plain X-rays in anteroposterior and lateral projections are standard; computed tomography or magnetic resonance imaging may be used to evaluate occult fractures, fracture extensions, or associated injuries.

Management is usually surgical. Preferred strategies include intramedullary or cephalomedullary nailing to achieve stable fixation and early mobilization; alternative fixation with locking plates is used in select cases. Nonoperative treatment is rarely appropriate for most subtrochanteric fractures due to instability.

Prognosis depends on fracture pattern, bone quality, and fixation quality. With appropriate fixation, healing can be achieved, but care is required to prevent complications such as malalignment, implant failure, and nonunion.