Define Intertrochanteric Fracture of the Femur. Describe its classification, investigations, management and complications.

Definition

An intertrochanteric (pertrochanteric) fracture is an extracapsular fracture of the proximal femur running between the greater and lesser trochanters. It is one of the commonest fractures in the elderly osteoporotic patient. Because the region is cancellous and richly vascular, union is the rule and avascular necrosis is rare — the problems here are blood loss, malunion (coxa vara) and implant failure, not non-union.

Mechanism & Clinical Features

Usually a fall on the greater trochanter in an elderly woman. The limb is markedly shortened and externally rotated (~90°) — more than in an intracapsular fracture because there is no intact capsule to restrain rotation. There is swelling, bruising and severe tenderness over the trochanter; the patient cannot bear weight. Significant blood loss into the thigh can cause hypovolaemia.

Classification

Boyd and Griffin and Evans classifications describe the pattern. The key clinical distinction is stable vs unstable. Stability depends on the integrity of the posteromedial cortex (calcar): comminution of the posteromedial fragment, a reverse oblique line, or subtrochanteric extension makes the fracture unstable and prone to collapse into varus.

Investigations

AP pelvis and lateral hip radiographs demonstrate the fracture and its comminution. Assess the posteromedial cortex and any reverse-oblique component for stability. Full pre-operative assessment and correction of anaemia/dehydration are important given the elderly population and blood loss.

Management

Treatment is almost always operative to allow early mobilisation and avoid the lethal complications of recumbency. Options: • Dynamic hip screw (DHS) — a lag screw in the head connected to a side-plate on the shaft. It allows controlled dynamic impaction at the fracture, ideal for stable patterns. • Cephalomedullary nail (PFN / PFNA / Gamma nail) — an intramedullary device with a cephalic screw/blade; the shorter lever arm and load-sharing make it the implant of choice for unstable, reverse-oblique and subtrochanteric patterns. • Arthroplasty is reserved for selected cases (e.g. Severe comminution with poor bone or pre-existing arthritis). Surgery should ideally occur within 48 hours, with DVT prophylaxis, early weight-bearing and osteoporosis management.

Subtrochanteric Extension

A fracture involving the region within 5 cm below the lesser trochanter is subtrochanteric. This is a high-stress area of predominantly cortical bone subjected to large compressive (medial) and tensile (lateral) forces, so it is prone to varus malunion and implant failure. A long cephalomedullary nail is the implant of choice. An ‘atypical’ subtrochanteric fracture (transverse, lateral cortical beaking) should raise suspicion of prolonged bisphosphonate use.

Peri-operative Care & Rehabilitation

Because these are frail, elderly patients, outcome depends as much on medical co-management as on the surgery: correction of anaemia and dehydration, analgesia, delirium prevention, pressure-area care, DVT prophylaxis and early nutritional support. Ortho-geriatric shared care and surgery within 48 hours reduce mortality. Post-operatively the aim is immediate weight-bearing as tolerated with physiotherapy, and secondary fracture prevention with calcium, vitamin D and bone-protection therapy.

Complications

General complications of immobility and high one-year mortality in the frail elderly. Mechanical: coxa vara / malunion from collapse of an unstable fracture, lag-screw cut-out, and implant breakage. Non-union and AVN are uncommon because of the good blood supply.

Extracapsular — avascular necrosis is rare, unlike neck fractures.

• Extracapsular → good blood supply → unites well; AVN & non-union rare.
• Limb shortened + externally rotated ~90° (more than intracapsular).
• Stability hinges on the posteromedial cortex (calcar).
• Stable → DHS; unstable / reverse-oblique / subtrochanteric → cephalomedullary nail.
• Avoid cut-out: good reduction + central deep screw + TAD < 25 mm.