A hip dislocation occurs when the ball-shaped head of the femur is forced out of the cup-shaped socket in the pelvis, known as the acetabulum. This severe orthopedic injury causes intense pain and immediately disables the leg. It requires a significant, high-impact force to displace the joint, which is typically stable due to its bony structure and strong ligaments. Common causes include motor vehicle collisions, falls from a height, or severe sports injuries. A dislocated hip is a medical emergency because delayed treatment can compromise the blood supply to the femoral head, leading to bone death, or avascular necrosis, and permanent damage to surrounding nerves and blood vessels.
Recognizing the Injury and Initial Stabilization
A hip dislocation presents with severe pain and the inability to move the affected leg. The injured leg often appears visibly shortened and is held in an unnatural, fixed position. In approximately 90% of cases, the dislocation is posterior, meaning the leg will be rotated inward and bent toward the center of the body.
Initial medical management focuses on stabilizing the patient before reduction. Medical professionals administer pain medication to manage the excruciating pain. A full neurovascular examination is performed immediately to check for nerve damage, particularly to the sciatic nerve, and to confirm adequate blood flow to the foot.
Plain X-rays of the hip and pelvis are obtained to confirm the dislocation and identify any associated fractures. If a fracture is present, the complexity of the injury increases and may change the reduction approach. Non-professionals should never attempt to move the injured person, as this could worsen the injury or cause further damage.
Methods for Joint Reduction
The primary goal of treatment is to return the femoral head to the acetabulum as quickly as possible, ideally within six hours of the injury to minimize avascular necrosis risk. The initial and preferred method for a simple dislocation (one without associated fractures) is Closed Reduction. This non-surgical procedure involves manually manipulating the leg to guide the femoral head back into the socket.
Closed reduction is performed under procedural sedation and anesthesia to relax the powerful hip muscles and provide pain relief. Multiple techniques exist, relying on the principles of traction and gentle rotation to disengage the femoral head and guide it into place. For the common posterior dislocation, the limb is typically flexed at the hip and knee, and a strong, sustained upward pull (traction) is applied.
Specific maneuvers, such as the Allis or Stimson techniques, use the patient’s body weight or the operator’s leverage to apply the necessary force. The process requires one or more assistants to maintain counter-traction on the pelvis while the primary operator performs the manipulation. A successful reduction is often accompanied by a distinct, audible or palpable “clunk” as the joint relocates.
If closed reduction fails or if imaging reveals significant associated fractures or soft tissue damage, Open Reduction becomes necessary. This surgical procedure is performed under general anesthesia. It allows the surgeon to directly visualize the joint, remove any bone fragments or soft tissue blocking the socket, and physically place the femoral head back into the acetabulum. Open reduction is often followed by internal fixation to stabilize associated fractures.
Immediate Monitoring and Acute Follow-up
Once the hip is reduced, the immediate follow-up phase begins. An immediate post-reduction X-ray is mandatory to confirm the position of the femoral head within the socket. A computed tomography (CT) scan is often obtained next to provide a more detailed look at the bony structures.
The CT scan helps identify small bone fragments that may have chipped off the femoral head or acetabulum, or fragments trapped inside the joint space. A repeat neurovascular examination is performed to check for any new or worsening nerve or blood vessel compromise resulting from the manipulation. Close monitoring of the limb’s sensation, motor function, and pulses is maintained for at least the first 24 hours.
Patients are generally admitted to the hospital following reduction, as the risk of the hip redislocating is highest in the first 24 to 48 hours. During this acute period, the hip is often immobilized in a position of slight abduction, sometimes with a pad placed between the legs to prevent adduction. This protective positioning prevents strain on the healing joint capsule and surrounding soft tissues.
Rehabilitation and Avoiding Recurrence
The long-term recovery process focuses on restoring function and preventing recurrence. The initial period following reduction typically involves restricted weight-bearing, often using crutches for several weeks, to allow soft tissues to heal. Physical therapy is essential for rehabilitation, designed to rebuild the muscular support around the hip joint.
Therapy starts with gentle range-of-motion exercises and progresses to isometric and strengthening activities for the hip flexors, extensors, and abductors. Strengthening the hip abductor muscles is important and correlated with a better functional outcome. Full recovery, allowing a return to high-level activities, can take three to four months, depending on the severity of the initial injury and associated soft tissue damage.
To avoid recurrence, patients must follow specific hip precautions for an extended period, limiting movements that strain the joint. For a posterior dislocation, this means strictly avoiding excessive hip flexion, internal rotation, and adduction across the midline. Precautions include avoiding bending the hip past 90 degrees, using a raised toilet seat, and not crossing the legs to protect the healing joint capsule.