CAISS Extremity Injuries 3 — Questions and Answers
Question 1: A patient sustains a closed femoral neck fracture. What AIS severity score is typically assigned?
- AIS 2
- AIS 3 (Correct answer)
- AIS 4
- AIS 5
Correct answer: AIS 3
A closed femoral neck fracture is coded AIS 3 (serious) in the AIS dictionary.
Question 2: In AIS coding of extremity injuries, what does 'NFS' (Not Further Specified) indicate?
- The injury is minor
- Specific anatomic detail is unavailable for precise coding (Correct answer)
- The injury involves the nervous system
- The fracture is non-displaced
Correct answer: Specific anatomic detail is unavailable for precise coding
NFS codes are used when documentation lacks sufficient detail to assign a more specific AIS descriptor.
Question 3: Which of the following tibial injuries would be coded at the highest AIS severity?
- Closed tibial plateau fracture
- Open tibial shaft fracture with compartment syndrome (Correct answer)
- Isolated fibula fracture
- Tibial stress fracture
Correct answer: Open tibial shaft fracture with compartment syndrome
An open tibial shaft fracture with compartment syndrome is the most severe option, reflecting both soft-tissue and perfusion compromise.
Question 4: How are bilateral lower extremity fractures handled in AIS scoring?
- Only the more severe side is scored
- Each injury is coded independently contributing to ISS calculation (Correct answer)
- Both are averaged into a single score
- They are combined into one AIS 6
Correct answer: Each injury is coded independently contributing to ISS calculation
Each injury is coded and scored independently; bilateral injuries each contribute to the overall Injury Severity Score.
Question 5: A laceration of the femoral artery at the groin without associated fracture is classified under which AIS body region?
- Abdomen
- Lower extremity (Correct answer)
- External
- Thorax
Correct answer: Lower extremity
Femoral artery injuries are classified under the lower extremity region in the AIS coding system.
Question 6: An AIS severity of 2 for a lower extremity injury most accurately corresponds to which clinical scenario?
- Femoral shaft fracture
- Non-displaced radial head fracture
- Simple closed fibula fracture (Correct answer)
- Traumatic below-knee amputation
Correct answer: Simple closed fibula fracture
A simple closed fibula fracture with minimal displacement is a moderate (AIS 2) injury requiring treatment but with low morbidity.
Question 7: For AIS coding purposes, degloving injury of the thigh without fracture is primarily characterized by injury to which tissue type?
- Bone
- Nerve
- Skin and soft tissue (Correct answer)
- Vasculature
Correct answer: Skin and soft tissue
Degloving injuries are skin and soft-tissue injuries coded under the appropriate severity based on extent and depth of involvement.
CAISS Extremity Injuries 3
A patient sustains a closed femoral neck fracture.
What AIS severity score is typically assigned?