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OR2.10-13 | Lower Limb Fractures — PBL Case

CLINICAL SETTING

Rajesh, a 28-year-old software engineer and amateur footballer, is brought to the emergency department at 11 PM following a high-speed road traffic accident. His motorcycle collided with a truck at an intersection. On arrival, paramedics report that he was conscious at the scene but has become increasingly agitated. He is on a backboard with a cervical collar. His right thigh is massively swollen and shortened, with obvious deformity. He is also complaining of pain in his right lower leg and right ankle. Initial observations: GCS 13/15, BP 94/68 mmHg, HR 124/min, SpO2 96% on 10 L O2 via non-rebreather mask, RR 22/min. No obvious chest or abdominal injury on rapid survey. His right leg is splinted. There is a 4 cm laceration over the medial aspect of the right ankle with exposed bone visible.

Trigger 1: Primary Survey and Haemorrhage Control

The trauma team activates. Primary survey: airway patent, bilateral breath sounds equal, abdomen soft. FAST scan: negative. Two large-bore IV lines placed. Pelvis stable. The right thigh fracture is identified as the likely source of haemorrhage. Pelvic binder is applied (negative exam, removed). 1 litre of Hartmann's solution is running. Initial blood work: Hb 9.2 g/dL, lactate 5.1 mmol/L, pH 7.28, base deficit −9. The right ankle wound shows bone protruding — a tibiotalar dislocation-fracture is suspected. Orthopaedics is called.

DISCUSSION POINTS

Using ATLS principles, classify this patient's haemorrhagic shock. What blood products and fluids would you administer and in what ratio?
The right thigh fracture is closed and displacing. How much blood can be lost into the thigh from a femoral shaft fracture, and how does this contribute to haemodynamic instability?
Should this patient undergo emergency operative fixation of the femoral shaft fracture tonight? Discuss the concept of damage control orthopaedics (DCO) versus early total care (ETC), using the patient's physiological parameters (lactate 5.1, pH 7.28, base deficit −9) to justify your decision.
The right ankle wound exposes bone. Apply the Gustilo-Anderson classification. What antibiotic(s) should be given, and within what time window?

Click to reveal Trigger 2: Day 2 Post-Stabilisation: Right Calf and the Ankle (discuss previous trigger first!)

Trigger 2: Day 2 Post-Stabilisation: Right Calf and the Ankle

Rajesh undergoes emergency temporary external fixation of the right femur (DCO) and wound debridement of the right ankle compound fracture. He is transfused 2 units pRBC and transferred to the ICU overnight. By the morning of Day 2, his lactate is 1.4, BP 118/76, HR 88. He is extubated. However, the bedside nurse flags that his right leg is now extremely tight and painful. The anterior compartment of the right leg is visibly tense. He shouts when the nurse passively dorsiflexes his right foot. Pulses: dorsalis pedis 1+, posterior tibial 1+. Sensation in the first web space is reduced. Compartment pressure is measured: anterior compartment 54 mmHg, BP 118/76 mmHg (diastolic 76 mmHg). Separately, his right ankle plain film shows a bimalleolar fracture with 4 mm lateral talar shift. CT ankle confirms a trimalleolar fracture with a posterior malleolar fragment involving 30% of the articular surface.

DISCUSSION POINTS

Calculate the delta pressure for this patient's anterior compartment. What does this value mean clinically, and what is the threshold for intervention? Explain why a palpable pulse does NOT exclude compartment syndrome.
Describe the four compartments of the lower leg and the nerve/vessel at risk in each. Which compartments must be released in a leg fasciotomy?
For the trimalleolar ankle fracture: using the Danis-Weber classification, classify the fibular fracture. Does the posterior malleolar fragment size (30% of articular surface) influence surgical decision-making? Justify the treatment plan.
The compound ankle wound has been debrided. When should definitive fixation of the ankle be performed, and what are the conditions that must be met before proceeding to ORIF?

Click to reveal Trigger 3: Day 3: Confusion, Petechiae, and the Path to Recovery (discuss previous trigger first!)

Trigger 3: Day 3: Confusion, Petechiae, and the Path to Recovery

Four-compartment leg fasciotomy was performed on Day 2. On Day 3, the nursing staff calls the orthopaedic registrar because Rajesh appears confused and is unable to state the date or year correctly. His SpO2 has dropped to 89% on room air. On examination: scattered petechiae are noted over his chest, axillae, and conjunctivae. Temperature 37.8°C. His chest X-ray shows bilateral diffuse opacities. ABG: PaO2 58 mmHg on 4 L O2 via nasal prongs. He is afebrile — no signs of surgical wound infection. His femoral fracture is still in the temporary external fixator.

DISCUSSION POINTS

What is the most likely diagnosis? Apply Gurd's diagnostic criteria to this patient's findings. Discuss the mechanical and biochemical theories of pathogenesis.
How does early operative stabilisation of the femoral shaft fracture (IMN) reduce the risk of this complication? Should the definitive femoral nailing now be delayed or expedited given this complication?
Outline the supportive management of this complication including respiratory support, monitoring parameters, and prognostic indicators.
Considering Rajesh's complete lower limb injury burden (femoral shaft + compartment syndrome + trimalleolar ankle fracture + open ankle injury), design a staged rehabilitation plan from ICU to discharge to outpatient follow-up, identifying the sequence of definitive procedures and early physiotherapy goals.

Learning Issues

Research these questions and bring your findings to the discussion.

[OR2.11] What are the aetiopathogenesis, clinical features, and diagnostic criteria of fat embolism syndrome following femoral shaft fractures? How does early intramedullary nailing reduce its incidence?
[OR2.10] What is the pathophysiology, clinical diagnosis, and emergency management of acute compartment syndrome following proximal tibial and distal femur fractures? What is the delta pressure threshold for fasciotomy?
[OR2.13] What is the Danis-Weber classification of ankle fractures? When is ORIF indicated, and what is the threshold for fixing the posterior malleolus?
[OR2.11] What are the principles of damage control orthopaedics (DCO) versus early total care (ETC) in multiply-injured patients with femoral shaft fractures? What physiological parameters guide this decision?
[OR2.12] How is the Gustilo-Anderson classification applied to open fractures? What are the antibiotic regimens for each grade, and why is the 1-hour antibiotic window critical?