1. Definition and Anatomy

• Greater trochanter - attachment of the gluteus medius and minimus (hip abductors)
• Lesser trochanter - attachment of the iliopsoas (hip flexor)
• The region between them is heavily trabecular and metabolically active bone

2. Etiology

Primary Risk Factors

Risk Factor Profile (from Rockwood & Green's, 10th ed.)

• Previous hip fracture (second fracture in up to 1 in 3 patients, average within 1.5 years)
• Impaired balance and gait (Parkinson's disease, stroke, neuropathy)
• Vision impairment
• Cognitive impairment and dementia
• Malnutrition
• Low BMI
• Multiple medications (e.g., sedatives, anticoagulants)
• Cardiovascular disease

High-Energy Mechanisms (Younger Patients)

• Motor vehicle accidents
• Falls from height
• Sports injuries

Epidemiology

• ~1.3 million trochanteric fractures worldwide annually (1990); projected to rise to 4.5 million/year by 2050
• A 12% increase in the US expected between 2010-2030
• Mortality rate: 20-25% at 1 year
• Functional independence loss: 30-50% of patients

3. Mechanism of Injury

Low-Energy (Elderly):

Deforming muscle forces after fracture:

• Proximal fragment (femoral head + neck + greater trochanter) - pulled into abduction and external rotation by short external rotators and gluteals
• Distal fragment (femoral shaft) - pulled upward and into varus by adductors and quadriceps; internally rotated relative to the head
• Net result: the limb appears shortened and externally rotated

4. Classification

OTA/AO Classification (Most Widely Used - Incorporated in National Hip Fracture Guidelines)

• Single fracture line running through the trochanters (intertrochanteric)
• Lateral wall intact
• Only two fragments; medial cortex interrupted in one place
• May be displaced or undisplaced
• Relatively stable - simpler to treat

• Main fracture line through trochanters
• Lateral wall essentially intact but coronal fragments at greater trochanter level (posterior and/or anterior)
• Lesser trochanter is detached from the shaft and femoral head fragment
• Minimum 3-4 main parts
• Termed "unstable trochanteric fracture"

• Fracture line runs from lesser trochanter to the lateral cortex (reverse oblique) OR transverse
• Lateral wall is unstable
• May extend into the subtrochanteric region
• Most challenging to treat; highest failure rates with extramedullary implants

Boyd and Griffin Classification (Historical, still referenced)

Concept of Lateral Wall Integrity

• An intact lateral wall (A1, A2) allows use of a sliding hip screw
• A compromised lateral wall (A3, some A2) mandates a cephalomedullary nail

5. Associated Injuries

Note: Head trauma must be actively excluded in all hip fracture patients. CT of the head is warranted in 21% of low-energy fracture patients.

6. Signs and Symptoms

Symptoms:

• Acute pain around the hip and thigh
• Inability to stand or walk (inability to bear weight)
• Pain may radiate to the ipsilateral knee
• History of a fall (usually from standing height in the elderly)

Clinical Signs on Examination:

Key point: In a non-displaced fracture, the classic shortening and external rotation may be absent. Axial compression pain along the limb axis is then the key diagnostic clue.

7. Investigations and Evaluation

Step 1 - Plain Radiographs (First-Line)

MRI showing an incomplete trochanteric fracture (arrow) - not visible on plain X-ray. This is treated conservatively.

• AP pelvis (must include both hips): confirms diagnosis; the non-injured hip helps plan reduction, assess varus and leg length
• Lateral hip X-ray: reveals excessive displacement, angulation, and coronal fracture lines - critical for operative planning
• 10-degree internal rotation AP: can unmask subtle fractures not seen on routine AP

• Traction view: evaluates pathologic lesion, lateral wall status, and fracture comminution

Step 2 - Advanced Imaging (If Diagnosis Uncertain)

Occult fractures: If plain X-rays are non-diagnostic but clinical suspicion remains, MRI is the investigation of choice. If MRI is unavailable, CT without contrast is the practical alternative.

Step 3 - Laboratory Investigations

• FBC (hemoglobin baseline, pre-operative)
• U&E, creatinine (renal function, fluid status)
• Clotting screen (anticoagulant medications)
• Bone profile (calcium, phosphate, ALP - screen for metabolic bone disease)
• Vitamin D and PTH levels
• Group and save / crossmatch
• ECG and Chest X-ray (pre-operative assessment)
• DEXA scan (post-fracture osteoporosis workup)

Step 4 - Medical History Priorities

• Pre-injury walking status and use of walking aids
• Living situation (independent vs. assisted living)
• Nutritional status
• Cognitive function
• History of prior fractures or hip surgery
• Presence of malignancy (isolated lesser trochanter fracture in a younger patient is a red flag for metastatic disease)

8. Treatment

A. Nonoperative Treatment (Rare Indications)

1. Undisplaced or incomplete fissure/crack fractures (detected on CT or MRI) in physically active persons
2. Non-ambulatory patients where adequate pain control can be achieved without surgery
3. Isolated, non-displaced greater trochanter fractures (displaced >1 cm may need tension band wiring)
4. Isolated lesser trochanter fractures without tumor (if pathologic - urgent operative fixation with IM nail)
5. Patient refusal or inability to tolerate surgery

• Skin traction (tapes to the affected leg)
• Skeletal traction (pin through proximal tibia or distal femur) - maintained for 4-8 weeks
• Analgesia

• Varus or valgus malunion
• Limb shortening
• Loss of muscle mass
• Prolonged hospital stay
• Thrombosis, pneumonia, pressure sores
• Nonunion

B. Operative Treatment (Standard of Care for A1, A2, A3)

• Analgesia (acetaminophen, opioids as needed; nerve blocks e.g., fascia iliaca block)
• Anesthesia and geriatric/medical consultation
• Thrombosis prophylaxis (LMWH or alternatives)
• Assessment of nutritional status, cognitive function, pre-injury mobility

Implant Selection Based on Fracture Type

1. Sliding Hip Screw (SHS) / Dynamic Hip Screw (DHS)

• Lateral approach to the femur
• Guidewire placed into femoral head in central-low position on AP, central on lateral
• Reaming of the femoral neck and head
• Insertion of the lag screw with barrel over it
• Side plate fixed to the femoral shaft (2, 4, or more holes)

2. Cephalomedullary Nail (CMN) / Intramedullary Nail

AP and lateral X-rays showing cephalomedullary nail fixation of a trochanteric hip fracture.

• Unstable fractures A2 and A3 (modern implant of choice)
• A3 reverse oblique/transverse fractures
• Any fracture with lateral wall compromise
• Subtrochanteric extension

• Reduced fracture collapse and shaft medialization
• Lower reoperation rates in A2 and A3 fractures
• Slightly lower mortality in some registry studies
• Better mobility outcomes with minimally invasive designs

• Short nail (~200 mm): adequate for fractures with extension no further than 3 cm below the trochanteric region
• Long nail: required if fracture extends below the lesser trochanter

• Static distal locking: provides length-stable rigid construct
• Dynamic distal locking: allows longitudinal compression; preferred for transverse fractures
• All short nails must be locked distally

X-ray demonstrating cephalomedullary nail with lag screw positioned in femoral head.

3. Proximal Femoral Locking Plate

• Rarely indicated for primary trochanteric fractures
• Static fixation - no opportunity for collapse
• High failure rates reported
• Possible role in periprosthetic fractures or young patients with complex fractures and good bone stock

4. Hemiarthroplasty / Total Hip Arthroplasty

• Uncommon for primary trochanteric fractures
• May be considered in failed internal fixation or pathologic fractures through the trochanteric region
• More commonly used for femoral neck (intracapsular) fractures

Surgical Decision Algorithm

Trochanteric Fracture Confirmed
         |
    ┌────┴────┐
Displaced?   Non-displaced
    |              |
  Stable?      Conservative
   (A1)         (watch)
    |
 Lateral wall
  intact?
    |         |
   YES        NO
    |          |
   SHS/DHS   CMN
    |
  A2 fracture?
    |
 Lateral wall
  still intact?
    |         |
  SHS OK    CMN preferred
    |
  A3 fracture?
    ↓
  ALWAYS CMN

Postoperative Management

• Immediate full weight-bearing as tolerated (goal in all patients)
• Physiotherapy and early mobilization from day 1 post-op
• Thromboprophylaxis (LMWH) for minimum 4 weeks
• Pressure area care, nutrition support, delirium prevention
• Osteoporosis treatment - bisphosphonates, denosumab, or teriparatide initiated at discharge
• Vitamin D and calcium supplementation
• Falls prevention assessment and intervention
• DEXA scan within 3 months

9. Complications

Intraoperative / Early:

• Excessive blood loss
• Iatrogenic fracture (nail insertion)

Late / Implant-Related:

10. Summary

1. Etiology - Primarily osteoporosis + fall from standing height in elderly women (mean age ~80); high-energy mechanisms in young patients
2. Mechanism - Direct impact to the greater trochanter causes the fracture; deforming muscle forces (gluteals + iliopsoas) produce the classic shortened, externally rotated limb
3. Classification (AO/OTA):
   • 31.A1 - Simple 2-part, stable, intact lateral wall
   • 31.A2 - Comminuted, unstable, detached lesser trochanter
   • 31.A3 - Reverse oblique/transverse, highly unstable, lateral wall disrupted
4. Associated injuries - ~4% have another fracture (wrist 2%, humerus 1%); always screen for head trauma (21% warrant CT head)
5. Signs - Hip pain + inability to weight bear; shortened, externally rotated limb (absent in non-displaced fractures - look for axial compression pain)
6. Investigations - AP pelvis + lateral hip X-ray; MRI for occult fractures; CT as alternative; full pre-op labs
7. Treatment:
   • A1: Sliding Hip Screw (DHS)
   • A2/A3: Cephalomedullary nail (modern standard)
   • Goal is same-day or next-day surgery with immediate post-op weight-bearing