8.1 Proximal Femur & Hip Fractures: Femoral Neck, Intertrochanteric & Subtrochanteric Fixation

Proximal Femur & Hip Fractures: Femoral Neck, Intertrochanteric & Subtrochanteric Fixation

Clinical Core Competency: Proximal femur (hip) fractures represent one of the most critical fragility and high-energy orthopaedic challenges in modern nursing practice. Distinguishing between intracapsular and extracapsular fracture patterns is paramount because their differing microvascular anatomy dictates surgical decision-making, mechanical failure modes, complication surveillance, and rehabilitation trajectories.

Hip fractures are a leading cause of morbidity, functional decline, and mortality in older adults. Over 95% of these fractures result from low-energy standing-height falls in individuals with underlying osteopenia or osteoporosis. Effective orthopaedic nursing requires rapid clinical identification, hemodynamic stabilization, structured geriatric risk stratification, multimodal opioid-sparing analgesia, and aggressive surveillance for perioperative complications.

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1. Classic Clinical Presentation & Physical Examination

When evaluating a patient with a suspected proximal femur fracture, the physical examination reveals characteristic postural and biomechanical abnormalities:

• Postural Deformity: The injured lower extremity typically rests in a shortened and externally rotated position. This classic presentation is driven by the unopposed contractual pull of the iliopsoas, gluteus maximus, and external rotators spanning across the fractured osseous envelope.
• Pain Localization & Movement: Severe groin, hip, or referred anteromedial knee pain (via the obturator and femoral nerves) is exacerbated by any gentle axial loading, active leg elevation, or passive internal/external rotation ("log-roll" test).
• Occult / Impacted Presentations (Garden I / II): Patients with nondisplaced, impacted femoral neck fractures may present with subtle groin or thigh discomfort, minimal deformity, and the preserved ability to bear partial weight. A high index of clinical suspicion is essential; plain radiographs showing subtle trabecular disruption must be confirmed with Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) to prevent catastrophic secondary displacement.

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2. Anatomical Classification: Intracapsular vs. Extracapsular

The fibrous hip joint capsule attaches anteriorly along the intertrochanteric line and posteriorly approximately 1 cm proximal to the intertrochanteric crest. This demarcation establishes two clinically distinct injury zones:

                    PROXIMAL FEMUR ANATOMIC CLASSIFICATIONS
  ┌──────────────────────────────────────────┬──────────────────────────────────────────┐
  │ INTRACAPSULAR FRACTURES                  │ EXTRACAPSULAR FRACTURES                  │
  ├──────────────────────────────────────────┼──────────────────────────────────────────┤
  │ • Subcapital, Transcervical, Basicervical│ • Intertrochanteric & Subtrochanteric    │
  │ • Bathed in synovial fluid               │ • Rich extracapsular blood supply        │
  │ • No periosteal callus (endosteal only)  │ • Abundant cancellous callus formation   │
  │ • High risk of vascular disruption (MFCA)│ • Rare AVN; high union rates (~98%)      │
  │ • High risk: AVN (20-40%) & Nonunion     │ • High blood loss & mechanical collapse  │
  └──────────────────────────────────────────┴──────────────────────────────────────────┘

Microvascular Vulnerability of the Femoral Head

The principal vascular supply to the femoral head arises from the deep branch of the Medial Femoral Circumflex Artery (MFCA), which forms an extracapsular arterial ring at the base of the neck. From this ring, ascending lateral retinacular arteries pierce the capsule and course subperiosteally along the femoral neck to supply the head. In geriatric patients, the artery of the ligamentum teres (foveal artery) is largely obliterated or supplies less than 10% of the capital femoral epiphysis. Consequently, displaced femoral neck fractures shear these delicate retinacular vessels, creating acute femoral head ischemia.

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3. Femoral Neck Fractures & Garden Staging

Femoral neck fractures are subclassified by the Garden Classification System, which evaluates the alignment of compressive trabecular bone on standard AP pelvic radiographs:

Surgical Fixation Decision-Making Matrix

1. Young, Physiologically Active Patients (< 60–65 years): Every effort is made to preserve the native femoral head. Even in displaced Garden III/IV fractures, emergency anatomical closed or open reduction and internal fixation (ORIF) with three parallel cannulated lag screws or a sliding hip screw is performed within 6–12 hours to decompress capsular tamponade and restore perfusion.
2. Geriatric Patients with Nondisplaced Fractures (Garden I & II): Treated with percutaneous in situ fixation using three parallel, cannulated screws in an inverted triangle configuration. This provides stable rotational and angular control while permitting immediate weight-bearing.
3. Geriatric Patients with Displaced Fractures (Garden III & IV): Primary joint replacement is the gold standard because internal fixation carries a 20–40% osteonecrosis rate and a 15–30% nonunion/hardware cutout rate:
   • Unipolar / Bipolar Hemiarthroplasty: Indicated for frail, lower-demand elderly patients, patients with baseline cognitive impairment, or those requiring shorter operative duration.
   • Total Hip Arthroplasty (THA): Indicated for active, cognitively intact older adults, independent community ambulators, or those with pre-existing symptomatic hip osteoarthritis, offering superior long-term functional scores and reduced reoperation rates.

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4. Extracapsular Fractures: Intertrochanteric & Subtrochanteric Fixation

Intertrochanteric Fractures

Intertrochanteric fractures occur in the broad zone between the greater and lesser trochanters. Because this region consists of dense, vascularized cancellous bone, nonunion and osteonecrosis are rare (<2%). However, these fractures are subject to massive bending moments and shear stresses.

• Stability Determinants: Fractures are classified as stable (intact posteromedial cortical buttress / lesser trochanter) or unstable (comminution of the posteromedial cortex, reverse obliquity fracture lines, subtrochanteric extension, or lateral wall blowout).
• Implant Mechanics:
  • Cephalomedullary Nail (CMN / Intramedullary Hip Nail): The implant of choice for all unstable, reverse obliquity, and subtrochanteric extension patterns. The intramedullary position provides a shorter lever arm and superior biomechanical load sharing, resisting medial collapse and varus deformities.
  • Dynamic Hip Screw (DHS / Sliding Hip Screw): An extramedullary side-plate and large lag screw that allows controlled sliding and dynamic impaction along the femoral neck axis. Highly effective for stable 2-part fractures, but prone to catastrophic cutout and medialization if utilized in unstable or reverse obliquity patterns.
  • Tip-Apex Distance (TAD): The sum of the distances from the screw tip to the femoral head apex on AP and lateral radiographs. A TAD < 25 mm is mandatory to prevent superior screw cutout through the femoral head.

Subtrochanteric Fractures

Subtrochanteric fractures occur within 5 cm distal to the lesser trochanter. This region consists of dense cortical bone with a relatively limited blood supply and is subjected to the highest compressive and tensile stresses in the human skeleton. Characteristic muscle forces cause extreme multi-planar deformity:

• Proximal Fragment Deformity: Flexed by the iliopsoas, abducted by the gluteus medius and minimus, and externally rotated by the short external rotators.
• Distal Fragment Deformity: Adducted and proximally shortened by the powerful pull of the adductor magnus, adductor longus, and hamstring muscle groups.
• Fixation: Requires a long, reamed, locked cephalomedullary intramedullary nail spanning the entire length of the femoral diaphysis to prevent stress risers at the distal tip.

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5. Orthogeriatric Co-Management & Perioperative Nursing Care

Modern evidence-based hip fracture care is anchored by collaborative orthogeriatric co-management models that streamline perioperative pathways.

                  ORTHOGERIATRIC HIP FRACTURE TIMELINE & GOALS
  ┌───────────────────────┬───────────────────────┬────────────────────────┐
  │ Emergency & Pre-Op    │ Surgical Window       │ Postoperative Recovery │
  │ (< 24 Hours)          │ (24 – 48 Hours)       │ (POD 1 – Day 35)       │
  ├───────────────────────┼───────────────────────┼────────────────────────┤
  │ • Hemodynamic Resusc. │ • Target OR: < 24-48h │ • WBAT Mobilization    │
  │ • FICB / PENG Block   │ • Minimize Delirium   │ • CAM Delirium Screen  │
  │ • Skin Traction/Bucks │ • Reversible Coagul.  │ • Extended VTE (35d)   │
  │ • Avoid Over-Sedation │   Reversal (DOAC/Warf)│ • Bowel / Skin Care    │
  └───────────────────────┴───────────────────────┴────────────────────────┘

Surgical Timing Benchmarks

Extensive clinical trials demonstrate that surgical fixation within 24 to 48 hours of admission significantly decreases 30-day and 1-year mortality, reduces surgical site infections, lowers delirium incidence, and shortens hospital length of stay. Delays beyond 48 hours are acceptable only for the correction of major, active, reversible clinical instability (e.g., severe electrolyte derangements, acute decompensated heart failure, or active bleeding requiring anticoagulant reversal).

Multimodal Analgesia & Regional Nerve Blocks

Systemic high-dose opioids in elderly trauma patients trigger delirium, respiratory depression, constipation, and hypotension. Orthopaedic nurses advocate for regional ultrasound-guided peripheral nerve blocks:

• Fascia Iliaca Compartment Block (FICB): Local anesthetic injected beneath the fascia iliaca blocks the femoral and lateral femoral cutaneous nerves (and occasionally the obturator nerve), providing profound anterior thigh and hip analgesia.
• Pericapsular Nerve Group (PENG) Block: Targets the articular sensory branches of the femoral, obturator, and accessory obturator nerves along the anterior hip capsule while sparing motor fibers to the quadriceps, preserving early postoperative motor strength.

Delirium Screening & Prevention

Delirium affects up to 50% of hospitalized hip fracture patients. Orthopaedic nurses perform serial screenings using the Confusion Assessment Method (CAM) or 4AT. Preventative nursing interventions include:

• Maintaining normal circadian sleep-wake cycles and minimizing nocturnal vital sign interruptions
• Ensuring sensory aids (hearing aids, eyeglasses) are applied immediately
• Avoiding high-risk medications on the Beers Criteria (e.g., diphenhydramine, benzodiazepines, meperidine)
• Early removal of indwelling urinary catheters within 24 hours postoperatively to reduce catheter-associated urinary tract infections (CAUTI) and agitation

Extended VTE Prophylaxis

Major orthopaedic trauma generates extreme venous stasis and endothelial injury. Current clinical guidelines (ACCP / AAOS) mandate extended venous thromboembolism (VTE) chemoprophylaxis (e.g., low-molecular-weight heparin [LMWH], direct oral anticoagulants [DOACs], or low-dose aspirin in low-risk patients) combined with mechanical sequential compression devices (SCDs) for 28 to 35 days post-injury.

Early Mobilization & Weight-Bearing Status

Unless explicitly restricted by the surgeon due to massive acetabular reconstruction, modern internal fixation (CMN) and arthroplasty protocols allow Weight-Bearing as Tolerated (WBAT). Physical therapy should initiate out-of-bed mobilization and progressive ambulation on Postoperative Day 1 (POD 1) to prevent atelectasis, sarcopenia, and thromboembolism.