ORTHOPEDICSTREATMENT
■ Nondisplaced patella fractures require immobilization in full extension
and advanced weight bearing as tolerated, with orthopedic referral.
■ Patella fractures with >3 mm displacement or loss of extensor function
mandate orthopedic referral for surgical intervention.
PATELLADISLOCATION
The patella usually displaces laterally over the lateral femoral condyle, as a
result of twisting of the knee with the leg held in a fixed position. This is
common in adolescent females.
TREATMENT
ED reduction is accomplished by placing the knee in full extension, the
hip in some flexion, and pushing on the patella in a medial direction up
and over the lateral condyle. Procedural sedation aids reduction. Once
reduced, immobilize in full extension.
A 30-year-old female is complaining of knee pain after a motor vehicle
collision. Exam shows a grossly deformed knee with lateral and rotational
displacement. What else do you need to evaluate in this patient and how
will you do so?
The patient has a knee dislocation. It is important to check pulses, motor,
and sensation, especially investigating for injury to the popliteal artery
(7–42% dislocations) and peroneal nerve injury (25–35%). Perform arterio-
graphy or check ABI (ankle brachial index); <0.8 is an indication for arterio-
gram. For evaluation of the peroneal nerve, check sensation of the dorsum of
the foot, and strength of dorsiflexion.KNEEDISLOCATION
Five types of knee dislocations (anterior and posterior are most common):
■ Anterior dislocation
■ Posterior dislocation
■ Medial dislocation
■ Lateral dislocation
■ Rotational dislocation
TREATMENT
■ Immediatereduction
■ Evaluate for neurovascular injury: Check ABIs or obtain arteriogram; test
peroneal and tibial nerves.
■ Posterior splint with immobilization in 15° of flexion
■ Obtain orthopedics +/−vascular surgery consultation.
COMPLICATIONS
■ Peroneal nerve injury(foot drop)
■ Popliteal artery injury especially with anterior and posterior dislocations
■ Less commonly, tibial nerve injury, ligamentous and meniscal injury
Ottawa Knee Rules
Obtain radiographs if at least
one of the following is true:
■Age > 55
■Fibular head tenderness
■Isolated tenderness of
patella
■Inability to flex knee to 90°
■Inability to bear weight in
the ED for four steps after
injury