DAMAGE CONTROL ORTHOPAEDICS
Polytrauma | Temporary Stabilization | Second Hit Prevention
PATIENT CATEGORIES
Critical Must-Knows
- DCO = temporary external fixation, delay definitive surgery until physiology normalizes
- Second hit phenomenon - surgery adds insult to already inflamed patient
- Borderline patients benefit most from DCO approach
- Start definitive surgery day 5-10 when inflammation subsides
- Lactate, pH, base deficit are key monitoring parameters
Examiner's Pearls
- "DCO prevents the 'second hit' of major surgery to inflammatory system
- "External fixation of femur reduces pulmonary complications in polytrauma
- "ISS greater than 20 + chest/head injury = consider DCO
- "Only borderline patients need decision-making - stable gets ETC, unstable gets DCO
Critical DCO Exam Points
DCO Indications
Polytrauma patients with physiological derangement from multiple injuries. Key is recognizing the borderline patient who may decompensate with definitive surgery. ISS greater than 20, bilateral femur fractures, or chest/head injury are triggers.
Second Hit Phenomenon
Major surgery is an inflammatory insult. In polytrauma, the patient is already in systemic inflammatory response. Adding surgery creates a second hit that can precipitate ARDS, MOF, and death. DCO delays this until inflammation subsides.
Physiological Parameters
Monitor lactate, pH, base deficit to assess resuscitation status. Do NOT proceed to definitive surgery until: pH greater than 7.25, lactate less than 4, base deficit less than 6, temperature greater than 35C, platelets greater than 50.
Timing of Definitive Surgery
Day 1-4: Window of opportunity (if patient very stable) or Day 5-10: Safe window after inflammatory response subsides. Avoid days 2-4 in borderline patients (peak inflammation).
Quick Decision Guide
| Patient Status | Physiology | Fracture Management | Key Pearl |
|---|---|---|---|
| Stable | Normal lactate, pH, hemodynamics | Early Total Care (ETC) - definitive fixation | This is the majority of trauma patients |
| Borderline | Moderate derangement, responding to resuscitation | DCO - external fixation, reassess daily | This group benefits most from DCO |
| Unstable | Ongoing hemorrhage, acidosis despite resuscitation | DCO mandatory - minimal intervention | Definitive surgery would be fatal |
| In Extremis | Moribund, cardiac arrest, perimortem | Hemorrhage control only, no fracture fixation | Focus on survival, not fractures |
DAMAGEDamage Control Orthopaedics Indications
Memory Hook:If DAMAGE is present, do DCO to prevent the second hit!
SAFEPhysiological Thresholds for Surgery
Memory Hook:Is the patient SAFE for definitive surgery? Check these parameters!
STOPSecond Hit Prevention
Memory Hook:STOP the second hit - stabilize temporarily and optimize before definitive surgery!
Overview and Epidemiology
Definition
Damage Control Orthopaedics (DCO) is a staged approach to managing fractures in polytrauma patients. The concept involves temporary stabilization (usually external fixation) followed by delayed definitive surgery once the patient's physiology has normalized.
Historical Context
Evolution from ETC to DCO:
- 1980s-1990s: Early Total Care (ETC) paradigm - early definitive fixation of all fractures
- Femoral nailing within 24 hours became standard
- Recognition that some patients deteriorated after early surgery
- Second hit phenomenon described - surgery adds inflammatory insult
- DCO concept developed for high-risk polytrauma patients
Rationale
The Second Hit Phenomenon:
- Major trauma causes systemic inflammatory response (SIRS)
- Additional surgical insult amplifies the inflammatory cascade
- Can precipitate ARDS, MOF, and death
- DCO minimizes surgical trauma until inflammation subsides
Not All Patients Need DCO
DCO is only for unstable or borderline patients. The majority of trauma patients (stable physiology) should receive Early Total Care (ETC) with definitive fixation. DCO in stable patients delays mobilization and increases infection risk.
Australian Context
Major trauma occurs throughout Australia with variable access to definitive care. DCO allows rural hospitals to stabilize fractures for safe transfer to tertiary trauma centers. External fixation is a core skill for all orthopaedic surgeons.
Pathophysiology
The Inflammatory Response to Trauma
First Hit - The Injury:
- Tissue damage releases damage-associated molecular patterns (DAMPs)
- Activation of innate immune system
- Cytokine release: IL-1, IL-6, TNF-alpha
- Systemic inflammatory response syndrome (SIRS)
- Compensatory anti-inflammatory response (CARS)
Second Hit - Surgical Insult:
- Additional tissue damage from surgery
- Further cytokine release
- Tips the balance toward hyperinflammation
- End-organ damage: lungs (ARDS), kidneys, liver
- Multi-organ failure (MOF)
Patient Classification
Polytrauma Patient Categories
| Category | Definition | Physiology | Management |
|---|---|---|---|
| Stable | Isolated injuries, responding to resuscitation | Normal lactate, pH, hemodynamics | ETC - definitive surgery |
| Borderline | Multiple injuries, moderate derangement | Lactate 2-4, mild acidosis, soft tissue injury | DCO vs ETC - individualized decision |
| Unstable | Ongoing hemorrhage, not responding | Lactate greater than 4, pH less than 7.25, coagulopathy | DCO mandatory |
| In Extremis | Moribund, cardiac arrest, perimortem | Unresponsive to resuscitation | Hemorrhage control only |
Borderline Patients are Key
Stable patients get ETC. Unstable patients get DCO. The decision-making challenge is the BORDERLINE patient. Use physiological parameters, injury pattern (ISS, chest injury), and clinical trajectory to decide. When in doubt, choose DCO.
Classification
Parameters to Guide Decision-Making
Pro-DCO Indicators (favor temporary fixation):
| Parameter | Threshold | Reasoning |
|---|---|---|
| pH | Less than 7.25 | Significant acidosis indicates poor perfusion |
| Lactate | Greater than 4 mmol/L | Marker of tissue hypoxia |
| Base deficit | Greater than 6 | Reflects degree of metabolic derangement |
| Temperature | Less than 35°C | Hypothermia impairs coagulation |
| Platelets | Less than 50 | Coagulopathy, ongoing hemorrhage |
| Transfusion | Greater than 10 units in 24h | Massive transfusion = unstable |
| INR | Greater than 1.5 | Coagulopathy |
Note: These are guidelines, not absolute cutoffs. Clinical judgment remains essential.
Clinical Assessment
Primary Survey
- ATLS principles first and foremost
- Control hemorrhage - pelvic binder, tourniquet
- Resuscitation with blood products
- Identify all injuries - tertiary survey essential
- Classify patient - stable, borderline, unstable, in extremis
Ongoing Assessment
- Trend physiological parameters - improving or deteriorating?
- Response to resuscitation - key decision point
- Serial lactate - most useful single parameter
- Reassess regularly - status can change rapidly
- Team communication - trauma team, anesthesia, ICU
Key Clinical Findings
Signs of Inadequate Resuscitation:
- Persistent tachycardia despite fluid
- Ongoing blood product requirements
- Rising or static lactate
- Worsening acidosis
- Cold peripheries, delayed capillary refill
Signs of Adequate Resuscitation:
- Normalizing heart rate
- Decreasing blood product requirement
- Falling lactate
- Improving acidosis
- Warm peripheries, urine output greater than 0.5ml/kg/hr
Do NOT Trust Blood Pressure Alone
Young patients compensate well. Blood pressure may be normal despite significant blood loss. Use lactate, base deficit, and clinical signs to assess perfusion. Hypotension is a LATE sign of decompensation.
Investigations
Laboratory Monitoring
| Parameter | Pro-ETC | Borderline | Pro-DCO |
|---|---|---|---|
| pH | Greater than 7.35 | 7.25-7.35 | Less than 7.25 |
| Lactate | Less than 2 | 2-4 | Greater than 4 |
| Base deficit | Less than 4 | 4-6 | Greater than 6 |
| Temperature | Greater than 36°C | 35-36°C | Less than 35°C |
| Platelets | Greater than 100 | 50-100 | Less than 50 |
Lactate is King
Serial lactate is the single most useful parameter. A falling lactate indicates adequate resuscitation. A rising lactate despite resuscitation indicates ongoing hemorrhage or inadequate perfusion - this patient needs DCO, not definitive surgery.
Management
Damage Control Orthopaedics Strategy
Goals of DCO:
- Temporary fracture stabilization
- Minimize surgical insult ("second hit")
- Control hemorrhage from fractures
- Allow patient resuscitation and optimization
- Enable safe transfer to ICU
Temporizing Measures:
- External fixation - pelvis, femur, tibia, humerus
- Splinting - forearm, ankle, foot
- Spanning plates - alternative for some sites
- Wound VAC - open fractures
What NOT to Do in DCO: Definitive ORIF, intramedullary nailing with extensive reaming, prolonged surgical time, or non-essential procedures.
Surgical Technique
Anterior Pelvic External Fixation
Indications:
- Unstable pelvic ring injury
- Ongoing hemorrhage
- Temporary stabilization
Technique: Position supine. Identify ASIS and iliac crest. Make 2cm incision over iliac crest, 3cm posterior to ASIS. Insert 5mm Schanz pins under image guidance, aiming toward AIIS. Two pins per side. Apply connecting bar across anterior pelvis. Tighten frame to reduce and stabilize.
Alternative: Pelvic C-clamp for posterior injuries (higher risk, requires experience).
Complications
Complications of DCO vs ETC
| Complication | DCO Risk | ETC Risk |
|---|---|---|
| ARDS | Lower in unstable patients | Higher if done in unstable patient |
| Pin site infection | 5-10% | N/A |
| Delayed union | Possible if prolonged external fixation | Lower |
| Multi-organ failure | Reduced by avoiding second hit | Higher in unstable patient |
| VTE | Similar | Similar |
Complications of External Fixation:
- Pin site infection (5-10%)
- Pin loosening
- Malunion if pins placed incorrectly
- Nerve injury from pin placement
- Conversion complexity if pins in nail path
Pin Site Infection and Conversion
Pin site infection increases risk of deep infection after conversion to internal fixation. If significant pin site infection develops, consider a staged approach: remove external fixator, treat infection, then definitive fixation after pin sites healed.
Postoperative Care
After DCO Stabilization
Daily Reassessment
Review physiological parameters daily. The goal is to convert to definitive fixation as soon as safely possible. Prolonged external fixation increases infection risk and complicates conversion surgery.
Outcomes and Prognosis
Evidence for DCO
Key Outcomes:
- Reduced ARDS in patients with femur + chest injury
- Lower mortality in borderline/unstable patients
- Comparable long-term outcomes when DCO used appropriately
Appropriate Patient Selection:
- DCO in stable patients = worse outcomes (delayed care)
- DCO in unstable patients = improved survival
- Key is identifying the borderline patient
Selection Bias
DCO vs ETC studies suffer from selection bias. Sicker patients get DCO, so direct comparisons are challenging. The principle of minimizing surgical insult in the already-stressed patient remains sound.
Evidence Base and Key Trials
Bone LB - DCO Original Concept
- First description of damage control orthopaedics concept
- Observations of deterioration after early femoral nailing in polytrauma
- Proposed staged management for high-risk patients
- Foundational paper for DCO philosophy
Pape HC - Timing of Femoral Nailing
- Retrospective analysis of timing of femoral nailing in polytrauma
- Early nailing (less than 24h) safe in stable patients
- Early nailing with chest injury increases ARDS risk (21% vs 4%)
- Borderline patients benefit from delayed fixation
Tuttle MS - Safe Definitive Surgery Timing
- Analysis of timing for conversion from external fixation to definitive fixation
- Day 5-10 is the safe window after initial inflammatory response subsides
- Earlier conversion (day 2-4) associated with higher complication rates
- Physiological parameters should guide timing decisions
Vallier HA - DCO vs ETC Outcomes
- Prospective comparison of DCO vs ETC in polytrauma
- No difference in outcomes when patients appropriately selected
- Key is correct patient categorization, not blanket approach
- Physiological parameters predict need for DCO
Roberts CS - Borderline Patient Criteria
- Proposed criteria for identifying borderline patients
- ISS greater than 20 = major polytrauma
- Bilateral femur fractures = high risk
- Femur + chest injury or head injury = DCO indicated
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
"A 28-year-old male is brought to ED following a high-speed motor vehicle accident. He has bilateral femoral shaft fractures and a pulmonary contusion. His lactate is 4.5, pH 7.28, and he has required 6 units of blood in the ED. How would you manage his femoral fractures?"
"Explain the concept of damage control orthopaedics and when you would apply it."
"A polytrauma patient had a femoral external fixator applied 3 days ago for DCO. Today their lactate is 1.5, pH 7.38, and they are hemodynamically stable off vasopressors. When would you convert to definitive fixation?"
MCQ Practice Points
Second Hit Phenomenon Question
Q: What is the 'second hit' phenomenon in polytrauma management? A: Major surgery causes an additional inflammatory insult to an already compromised patient. This can precipitate ARDS and multi-organ failure. DCO minimizes this by delaying definitive surgery until the initial inflammatory response subsides.
DCO Indications Question
Q: What are the physiological thresholds that indicate a patient needs DCO rather than ETC? A: pH less than 7.25, lactate greater than 4 mmol/L, base deficit greater than 6, temperature less than 35°C, platelets less than 50,000. Also consider DCO for ISS greater than 20, bilateral femur fractures, or femur + chest/head injury.
Timing of Conversion Question
Q: When is the optimal time to convert external fixation to definitive fixation in DCO patients? A: Day 5-10 after injury. This is the immunological window after the initial inflammatory peak (days 2-4) has subsided. Convert when physiological parameters normalize (lactate less than 2, pH greater than 7.35).
Patient Categories Question
Q: What are the four patient categories in DCO decision-making? A: Stable (ETC appropriate), Borderline (individualized decision based on parameters), Unstable (DCO mandatory), In Extremis (hemorrhage control only, no fracture fixation).
Femur-Chest Combination Question
Q: Why is femoral fracture + chest injury a classic DCO indication? A: Early femoral nailing increases pulmonary complications in patients with chest injury (21% ARDS vs 4% with DCO). External fixation allows fracture stabilization without the second hit of intramedullary reaming.
Lactate Monitoring Question
Q: What is the single most useful parameter for monitoring resuscitation adequacy in polytrauma? A: Serial lactate. Falling lactate indicates adequate tissue perfusion. Rising or static lactate despite resuscitation suggests ongoing hemorrhage or inadequate perfusion - this patient needs DCO approach.
Australian Context
Trauma System
- Major trauma centers in capital cities
- Rural/remote patients transferred after stabilization
- DCO allows safe inter-hospital transfer
- Retrieval services coordinate complex transfers
Training Requirements
- External fixation is SET competency requirement
- All orthopaedic trainees should be proficient
- Pelvic external fixation for hemorrhage control
- EMST course teaches DCO principles
Rural and Remote Considerations
DCO is particularly relevant for rural Australia. Patients may require stabilization at a regional hospital before transfer. External fixation allows fracture control for safe transport over long distances.
DAMAGE CONTROL ORTHOPAEDICS
High-Yield Exam Summary
Patient Categories
- •Stable: ETC - definitive fixation
- •Borderline: Decision point - use parameters
- •Unstable: DCO mandatory
- •In Extremis: Hemorrhage control only
DCO Indications
- •pH less than 7.25
- •Lactate greater than 4
- •ISS greater than 20
- •Bilateral femur or femur + chest injury
- •Ongoing hemorrhage despite resuscitation
Second Hit Phenomenon
- •Surgery is inflammatory insult
- •Can precipitate ARDS, MOF
- •DCO minimizes surgical trauma
- •Allow inflammation to subside
Timing
- •Day 0-1: Window of opportunity if stable
- •Day 2-4: Avoid surgery (peak inflammation)
- •Day 5-10: Safe window for conversion
- •Monitor lactate, pH, base deficit