Posterior dislocation of tibia on femur

A posterior dislocation of the tibia on the femur is a serious injury that involves the displacement of the tibia (shinbone) posteriorly (backward) in relation to the femur (thighbone) at the knee joint. This type of dislocation is often associated with high-energy trauma, such as motor vehicle accidents or severe sports injuries. Posterior knee dislocations are relatively uncommon but can result in significant damage to the surrounding structures.

Here are some key points about posterior dislocation of the tibia on the femur:

  1. Mechanism of Injury:
  • High-impact forces, such as those encountered in car accidents or certain sports injuries, are typically responsible for posterior knee dislocations.
  • The posterior displacement occurs when a force is applied to the front of the knee while the foot is fixed, causing the tibia to move backward in relation to the femur.
  1. Injury Patterns:
  • Posterior knee dislocations are often associated with injuries to ligaments, blood vessels, nerves, and other soft tissues around the knee.
  • Commonly affected structures include the posterior cruciate ligament (PCL), anterior cruciate ligament (ACL), medial collateral ligament (MCL), and the popliteal artery and nerves.
  1. Clinical Presentation:
  • Patients with a posterior knee dislocation may experience severe pain, swelling, and deformity of the knee.
  • There may be associated neurovascular deficits due to potential injury to blood vessels and nerves in the popliteal region.
  1. Complications:
  • Vascular injury: Posterior knee dislocations can lead to damage to the popliteal artery, which may compromise blood supply to the lower leg. This is a medical emergency.
  • Nerve injury: Injury to the nerves in the popliteal fossa can result in sensory or motor deficits.
  • Ligamentous injuries: The PCL is commonly injured in posterior knee dislocations, and other ligaments may be affected as well.
  1. Treatment:
  • Immediate reduction (repositioning) of the dislocated joint is crucial. This is often performed in a hospital setting by healthcare professionals.
  • Surgical intervention may be required to address associated injuries, including ligament reconstruction and repair of damaged blood vessels and nerves.
  • Rehabilitation and physical therapy are important components of the recovery process.

Posterior knee dislocations are considered medical emergencies due to the potential for vascular compromise, and prompt evaluation and treatment are essential to minimize complications and improve outcomes. Management typically involves a multidisciplinary approach with orthopedic surgeons, vascular surgeons, and other specialists as needed.