8.2 Diaphyseal & Articular Fractures of the Lower Extremity (Femur, Tibia, Ankle & Foot)

Diaphyseal & Articular Fractures of the Lower Extremity (Femur, Tibia, Ankle & Foot)

Trauma Nursing Perspective: Lower extremity fractures encompass a wide spectrum of kinetic energy transfer, from high-velocity motor vehicle collisions causing massive closed soft-tissue degloving and shock to axial compression injuries flattening articular surfaces. The orthopaedic nurse plays a crucial role in hemodynamic resuscitation, compartment pressure surveillance, neurovascular preservation, and maintaining strict post-reduction immobilization.

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1. Femoral Shaft Fractures: Hemorrhage, Traction & Intramedullary Nailing

The femoral diaphysis is enveloped by the body's largest muscle masses. Fractures of the femoral shaft (AO/OTA Type 32) typically result from high-velocity kinetic impact (motor vehicle collisions, falls from significant heights, or gunshot wounds).

                     FEMORAL SHAFT TRAUMA CASCADE
  ┌─────────────────────┐     ┌─────────────────────┐     ┌─────────────────────┐
  │ HIGH-ENERGY IMPACT  │ ──> │ INTERNAL HEMORRHAGE │ ──> │ RESUSCITATION &     │
  │ Diaphyseal cortical │     │ 1,000 – 1,500 mL    │     │ TRACTION SPLINTING  │
  │ disruption (Type 32)│     │ Thigh sequestration │     │ Hare / Sager / Skel.│
  └─────────────────────┘     └─────────────────────┘     └─────────────────────┘
                                         │
                                         ▼
                              ┌─────────────────────┐
                              │ DEFINITIVE SURGERY  │
                              │ Reamed IM Nailing   │
                              │ or Damage Control   │
                              └─────────────────────┘

Hemodynamic Impact & Blood Loss

Closed femoral shaft fractures routinely sequester 1,000 to 1,500 mL of blood within the tight fascial compartments of the thigh. In bilateral femoral fractures, blood loss frequently exceeds 2,500 to 3,000 mL, inducing severe class II or class III hypovolemic hemorrhagic shock. Orthopaedic nurses must initiate rapid large-bore IV access (two 16-gauge or 14-gauge peripheral lines), administer balanced crystalloids/blood products, monitor serial hemoglobin/hematocrit and lactate levels, and track thigh circumference.

Emergency Traction Splinting

In the prehospital and emergency department setting, immediate application of a traction splint (e.g., Hare, Sager, or Thomas splint) is standard of care for isolated closed mid-shaft femur fractures:

• Therapeutic Goals: Realigns the bone fragments, restores resting anatomic length, dramatically decreases muscle spasm and pain, and tamponades bleeding within the thigh musculature.
• Contraindications: Suspected pelvic ring fracture, ipsilateral hip/femoral neck fracture, severe knee ligamentous disruption, or ipsilateral ankle/foot open injury.

Definitive Fixation & Damage Control Orthopaedics (DCO)

• Reamed Locked Intramedullary (IM) Nailing: The gold standard definitive treatment, providing biological, load-sharing internal fixation that permits early progressive ambulation.
• Damage Control Orthopaedics (DCO): In polytrauma patients presenting in physiological distress (the "lethal triad" of hypothermia, acidosis, and coagulopathy, or severe concomitant thoracic trauma with ARDS), prolonged reamed IM nailing is contraindicated due to the risk of a secondary inflammatory "second hit." Patients receive rapid temporary stabilization with a spanning external fixator (<30 minutes), followed by ICU resuscitation and delayed conversion to definitive IM nailing between days 5 and 10.
• Fat Embolism Syndrome (FES) Surveillance: High risk in unreduced femoral shaft fractures. Nurses monitor for Gurd's classic triad: hypoxemia (PaO2 < 60 mmHg), neurological confusion/agitation, and a petechial rash across the axillae, neck, and subconjunctiva appearing 24 to 72 hours post-injury.

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2. Tibial Shaft Fractures & Acute Compartment Syndrome

The tibial diaphysis is the most commonly fractured long bone in the human body. Because its anteromedial border lies directly subcutaneous with zero muscular coverage, tibial shaft fractures (AO/OTA Type 42) carry the highest rate of open fracture conversion (up to 25%) and the highest incidence of Acute Compartment Syndrome (ACS, ~10%) of any skeletal injury.

                   TIBIAL COMPARTMENTS & NEUROVASCULAR STRUCTURES
  ┌──────────────────────┬─────────────────────────────┬──────────────────────────────┐
  │ Compartment          │ Muscular Contents           │ Neurovascular Bundle         │
  ├──────────────────────┼─────────────────────────────┼──────────────────────────────┤
  │ 1. Anterior          │ Tibialis ant., EHL, EDL     │ Deep Peroneal Nerve, ATA     │
  │ 2. Lateral           │ Peroneus longus and brevis  │ Superficial Peroneal Nerve   │
  │ 3. Superficial Post. │ Gastrocnemius, Soleus       │ Sural Nerve                  │
  │ 4. Deep Posterior    │ Tibialis post., FHL, FDL    │ Tibial Nerve, PTA, Peroneal A│
  └──────────────────────┴─────────────────────────────┴──────────────────────────────┘

Pathophysiology & Nursing Surveillance for ACS

Fracture hematoma and post-traumatic tissue edema elevate interstitial fluid pressure within the non-compliant fascial envelopes of the lower leg. When tissue pressure approaches within 30 mmHg of the patient's diastolic blood pressure (ΔP = Diastolic BP - Intracompartmental Pressure ≤ 30 mmHg), capillary perfusion ceases, causing irreversible ischemic neuromuscular necrosis within 6 to 8 hours.

• Early Hallmarks: Severe, unremitting, burning pain disproportionate to the apparent injury that is refractory to escalating intravenous opioids, and exquisite pain elicited upon passive stretching of the muscles residing in the involved compartment (e.g., passive great toe plantarflexion stretching the ischemic anterior compartment).
• Late / Irreversible Signs: Paresthesia in the first web space, followed by motor paralysis (foot drop) and pulselessness. Pulselessness indicates established tissue death and is NOT required for diagnosis.
• Nursing Actions: Immediately place the extremity at heart level (NEVER elevate above heart level, as this reduces arterial perfusion pressure, and NEVER place in dependency), completely split/bivalve all circumferential plaster casts or tight dressings down to bare skin, discontinue any regional anesthetic infusions that mask pain, and alert the orthopaedic trauma surgeon for emergent four-compartment double-incision fasciotomy.

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3. Tibial Plateau Fractures: The Schatzker Classification

Tibial plateau fractures involve the proximal articular surface of the tibia and result from axial compressive loads combined with varus or valgus bending forces (e.g., car bumper striking a pedestrian's lateral knee, skiing falls, or falls from heights).

Clinical Management & Rehabilitation

• Type IV Warning: The medial plateau is significantly stronger than the lateral plateau; a fracture here implies high kinetic energy. Nurses must perform hourly bilateral dorsalis pedis and posterior tibial pulse checks, obtain Ankle-Brachial Indices (ABI, normal > 0.9), and assess common peroneal nerve sensation (first dorsal web space) and motor function (ankle/great toe dorsiflexion).
• Rehabilitation: Operative stabilization involves open reduction and internal fixation (ORIF) with subchondral rafting screws and buttress plating. Patients are maintained on strict Non-Weight-Bearing (NWB) for 6 to 12 weeks to allow cancellous bone consolidation and prevent articular step-off collapse. Early passive range of motion is initiated once soft-tissue swelling subsides.

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4. Ankle Fractures: Danis-Weber Staging & The Maisonneuve Fracture

The ankle joint is a highly congruent ring structure comprising the distal tibia (plafond and medial/posterior malleoli), distal fibula (lateral malleolus), talus, and the distal tibiofibular syndesmosis (anterior-inferior tibiofibular ligament [AITFL], posterior-inferior tibiofibular ligament [PITFL], and interosseous ligament/membrane).

                  DANIS-WEBER ANKLE FRACTURE CLASSIFICATION

     Weber A (Infrasyndesmotic)     Weber B (Transsyndesmotic)     Weber C (Suprasyndesmotic)
   ┌───────────────────────────┐  ┌───────────────────────────┐  ┌───────────────────────────┐
   │      Tibia     Fibula     │  │      Tibia     Fibula     │  │      Tibia     Fibula     │
   │        │         │        │  │        │         │        │  │        │       ==*== (Fx) │
   │        │         │        │  │        │       ==*== (Fx) │  │        │         │        │
   │      Syndesmosis (Intact) │  │      Syndesmosis (Partial)│  │      Syndesmosis (Torn)   │
   │        │       ==*== (Fx) │  │        │         │        │  │        │         │        │
   │     [Talar Mortise]       │  │     [Talar Mortise]       │  │     [Widened Mortise]     │
   │  Stable; Non-op Cast/Boot │  │  Variable Mortise Stability│  │  Unstable; ORIF + Screw  │
   └───────────────────────────┘  └───────────────────────────┘  └───────────────────────────┘

Danis-Weber Classification Hierarchy

1. Weber A (Infrasyndesmotic): Fibular fracture occurs distal to the level of the tibial plafond/syndesmosis. The syndesmosis and medial structures remain completely intact. The ankle mortise is stable. Treatment is conservative with a weight-bearing walking boot or short-leg cast.
2. Weber B (Transsyndesmotic): Oblique or spiral fibular fracture occurs at the exact level of the syndesmosis. The syndesmosis may be partially torn. Stability depends on the medial side: if the medial malleolus is fractured or the deltoid ligament is torn (evidenced by medial clear space widening > 4 mm on stress radiography), the ankle is unstable and requires ORIF.
3. Weber C (Suprasyndesmotic): Fibular fracture occurs proximal to the syndesmosis anywhere along the fibular shaft. The syndesmotic ligaments and interosseous membrane are completely torn, resulting in gross ankle mortise widening and talar tilt. Weber C injuries are inherently unstable and mandate anatomic ORIF of the fibula combined with syndesmotic screw or suture-button (TightRope) fixation.

The Maisonneuve Fracture: A Critical Nursing Trap

A Maisonneuve fracture is a specific high-energy pronation-external rotation injury characterized by:

• Rupture of the medial deltoid ligament or avulsion of the medial malleolus
• Complete longitudinal tearing of the interosseous membrane and syndesmosis
• A spiral fracture of the proximal third / neck of the fibula

Mandatory Clinical Rule: In any patient presenting with acute ankle trauma, medial swelling, or medial clear space widening on X-rays without an apparent distal fibular fracture, the nurse and examiner MUST palpate the entire length of the fibula up to the proximal fibular head. Failing to palpate the proximal fibula leads to missed Maisonneuve fractures, persistent joint instability, and rapid post-traumatic osteoarthritis.

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5. Foot Trauma: Calcaneal Fractures & Lisfranc Midfoot Complex

Calcaneal Fractures & The Böhler Angle

Calcaneal fractures represent the most frequent tarsal injury, caused by high-energy axial loading (e.g., falling from a ladder or jumping from a roof, landing directly on the heels). Over 75% are intra-articular, involving the subtalar joint.

• Böhler Angle: Measured on a lateral foot radiograph between lines drawn from the highest points of the posterior tuberosity, subtalar articular facet, and anterior process. Normal is 20° to 40°. Axial impaction collapses the posterior facet, flattening the angle to < 20°.
• Associated Spinal Trauma: Due to the axial transmission of kinetic energy, approximately 10% of calcaneal fracture patients have a concomitant lumbar spine compression fracture (L1–L3). Complete spinal palpation and log-roll precautions are mandatory.
• Soft-Tissue Envelope Care: Calcaneal trauma causes massive heel edema and fracture blister formation. Surgery is strictly delayed for 10 to 14 days until the "wrinkle sign" (skin puckering upon gentle ankle dorsiflexion/eversion) returns, signaling resolution of interstitial edema.

Lisfranc Injury (Tarsometatarsal Joint Complex)

The Lisfranc joint forms the transverse arch of the midfoot, where the metatarsal bases articulate with the three cuneiforms and cuboid. The critical Lisfranc ligament anchors the medial cuneiform to the base of the 2nd metatarsal.

• Clinical Presentation: Pain localized to the midfoot, inability to bear weight on the forefoot, and a pathognomonic plantar ecchymosis sign (bruising on the sole/plantar surface of the midfoot).
• Diagnostic Evaluation: Non-weight-bearing plain films often appear deceptively normal. Bilateral standing weight-bearing radiographs (AP, lateral, and 30° oblique) are mandatory to unmask diastasis (> 2 mm widening between the 1st and 2nd metatarsal bases) or loss of the longitudinal arch.
• Treatment: Nondisplaced ligamentous sprains require 6 weeks of strict non-weight-bearing casting. Any displacement > 2 mm mandates anatomic ORIF with trans-articular screws or primary midfoot arthrodesis.