L17 - Lower limb trauma Flashcards
What could be the possible anatomical consequences of an injury?
- Fracture
- Dislocation
- Soft tissue injury
What could be the possible physiological consequences of an injury?
- Bleeding and shock
- Coagulopathy; coagulation change as clotting factors used up
- Multiple organ failure depending on reaction to injury (how fast or slow)
Describe the anatomy and energy of pelvic fractures?
Energy + anatomy = injury
Energy - often high (e.g. going at v fast speed into stationary object)
Anatomy - often strong bone and ligaments
What are the two main ligaments of the pelvis?
- Sacrospinous ligament
- Sacrotuberous ligament
- Also iliolumbar ligament
What is the main function of ligaments within the pelvis?
Control of sagittal tilt of spine
- Mechanical stabilisers of the pelvic girdle, primarily against rotational forces in the sagittal and horizontal planes
What are the ligaments of the sacroiliac joint?
- Anterior sacroiliac ligament
- Interosseous sacroiliac ligament
- Posterior sacroiliac ligament
- Transfers weight and forces between your upper body and legs
What are the ligaments of the pubic symphysis?
- Superior pubic ligament
2. Arcuate ligament
Describe the APC mechanism of injury
Antero-posterior compression
- anterior or posterior forces applied to the anterior or posterior superior iliac spine areas
- Pelvic fractures (espec APC) are notorious for mortality owing to bleeding
- Pelvic floor may be torn by injury
What is a dynamic hip screw?
- Sliding screw fixation
- Allows controlled dynamic sliding of the femoral head component along the construct
- Used for internal fixation of fractures of the femoral neck and intertrochanteric region
What are the different classifications of an APC injury?
- APC-I
- APC-II
- APC-III
What are the features of an APC-I injury?
- Slight widening of pubic symphysis and/or anterior SI joint
- Stretched BUT INTACT anterior SI, sacrotuberous and sacrospinous ligaments
- Intact posterior SI ligaments
What are the features of an APC-II injury?
- Widened anterior SI joint, disrupted anterior SI, sacrotuberous, sacrospinous ligaments
- Intact SI ligaments
- Splaying of anterior pelvis with external rotation of iliac wings swinging open at posterior aspect of SI joints
What are the features of an APC-III injury?
- Complete SI joint disruption with lateral displacement
- Disrupted anterior SI, sacrotuberous, sacrospnous ligamentsand disrupted posterior SI ligaments
What volume of blood leaking per min is lethal within 2 hours?
20mlmin^(-1) of bleeding for 2 hours would be lethal
How could you treat the bleed?
Using an angiogram, use an embolisation coil to stop the bleeding
Describe the energy and anatomy of hip fractures
Fractured neck of femur
Energy - usually low (e.g. fall<2m)
Anatomy - usually weak bone (may be from osteoporosis)
- Common in elderly where they are frail
What are the 3 types of hip fractures?
- Intracapsular
- Trochanteric
- Subtrochanteric
ARE NOT:
- Acetabular fractures
- Femoral head fractures
What is an intracapsular hip fracture?
- Makes up 58% of hip fractures
- Occurs at the level of the neck and the head of the femur
- Generally within the capsule
What is a trochanteric fracture?
- Makes up 34% of hip fractures
- Occurs between the greater trochanter, (where the gluteus medius and the gluteus minimus attach) and the lesser trochanter (where the iliopsoas attaches)
What is a subtrochanteric fracture?
- Makes up 5% of hip fractures
- Occurs between lesser trochanter and 5cm below lesser trochanter
Describe the deformity seen in hip fractures
- Can be observed from end of bed
- Lower limb is shortened and externally rotated
- Heel height of damaged limb is higher than the other limb
- Internal rotation can be easily lost
- Lesser trochanter appears more prominent in external rotation
Why can the lower limb be shortened in a hip fracture?
- Shortening by pull of muscles crossing hip
- Muscles may spasm due to the fracture therefore leading to the shortening
Which artery could be injured in an intracapsular hip fracture?
- Lateral femoral circumflex artery
- Retinacular arteries
- Medial femoral circumflex artery
(- Profunda femoris artery)
What does bone healing depend on?
- Stability
- Blood supply
What are the main complications following fractures of the femoral neck>
- Nonunion (lacking adequate stability of blood flow)
- Avascular necrosis of the femoral head
