Fixators

Fixators are devices used in musculoskeletal medicine to immobilize, align, or lengthen bones and surrounding tissues during healing. The term covers both external devices attached outside the body and internal devices implanted inside the body that mechanically stabilize the fractures.

External fixators are frames outside the body connected to bone via pins or wires that traverse skin and bone. They stabilize fractures, allow treatment of severe open injuries, manage soft-tissue damage, and correct deformities or limb-length differences. Ring fixators (Ilizarov-type) and unilateral frames are common; many systems are adjustable and can be computer-assisted.

Internal fixators include plates and screws and intramedullary nails that stabilize from inside the bone. They provide rigid fixation, enable early motion, but require surgery to place and remove and can limit soft-tissue access in some injuries.

Hybrid fixators combine external and internal elements to tailor treatment to the fracture pattern and soft-tissue condition.

Indications: open or comminuted fractures, unstable intra-articular injuries, limb-length discrepancy, nonunions, malunions, and deformities. Principles: achieve stable alignment while preserving blood supply, allow controlled motion, and, with external frames, perform gradual distraction or compression as healing progresses.

Complications: pin tract infection, loosening, neurovascular injury, refracture after removal, stiffness, and malalignment. Care includes pin-site hygiene, regular X-rays, and patient education; removal follows radiographic healing.

History: The Ilizarov ring fixator popularized external limb reconstruction in the mid-20th century. Since then, external and internal fixators have evolved, including modular and computer-assisted hexapod systems.