Hip And Femur Injuries Flashcards
What type of prosthetic hip dislocation is most common?
Most are performed through the posterior approach so posterior dislocations are by far the most common
How do prosthetic POSTERIOR hip dislocations happen? (MOI)
Occur from flexion, adduction, and internal rotation
- going from a low-seated position to a standing position
- getting out of a booth, bending over to clip toenails, and standing up from the toilet are common mechanisms
How do prosthetic ANTERIOR hip dislocations happen? (MOI)
Hyperextension of the hip
- more awkward and less common in ADLs
How are prosthetic hip dislocations managed?
Posterior: Reduced using procedural sedation in the ED with normal reduction techniques
Anterior: simple gradual longitudinal traction on the dislocated leg while assistant stabilizes the pelvis (Allis leg extension method)
Before reducing a prosthetic hip dislocation?
BC of the variability of implants and approaches, attempt to contact the surgeon who performed the arthroplasty prior to reduction attempts.
Which type of hip dislocations is most common?
Posterior - due to anterior-posterior MOI and weaker posterior joint capsule
Posterior is 90% of native hip dislocations
Anterior and anterior-inferior account for the remaining 10%
Prevalence of prosthetic hip dislocations?
10% of prosthetic hips will dislocate
- most in the first few months after surgery
What types of injury/patient should make you concerned for hip fx or dislocation?
Elderly falls
Altered found down
High energy MVC
CKD patients
Prolonged steroid use
Malignancy
What type of force causes a posterior hip dislocation?
Force applied to a flexed knee, MC dashboard injury
- often associated with acetabular, femoral neck, and femoral shaft fractures
- knee ligamentous injuries are also common
What type of injury leads to anterior hip dislocations?
** rare**
Forced abduction that causes the femoral head to be levered out through an anterior capsular tear.
Types of anterior hip dislocations
Superior (Pelvic) or inferior (obturator) depending on degree of hip flexion at time of injury
What population has most hip and femur fx?
- what do you need to consider with this population and these injuries?
Maj occur in elderly.
Consider elder abuse or self-neglect in patients with suspicious injuries
What causes AVN in hip dislocations?
o Dislocations always rupture the teres ligament and the foveal artery
o Always result in AVN if no alternate blood supply
o AVN occurs in 15-35% of hip fracture when capsular vessels are disrupted
What type of fracture rarely causes AVN?
Intertrochanteric fractures
What nerve complication occurs in approx 10% of posterior dislocation patients?
Sciatic nerve injury
