If a bone is broken as a result of trauma or is cut during surgery for deformity correction or lengthening, it needs to be stabilized to allow it to become strong again. Internal devices such as plates, screws, and nails or external devices such as simple or complex frames can be used to control and fix bone segments.
Although fractures and simple single-plane deformities are often fixed with plates and screws, bone lengthening is achieved with internal lengthening nails or external fixators. Pseudarthrosis (non-united bones) resulting from poor bone quality or poor blood supply and/or in the presence of infection can be well managed with external frames, even after multiple previous surgical attempts at healing.
Complex deformities of the long bones and the foot (e.g., severe recurrent clubfoot) can gently and gradually be corrected using software-guided six-axis external frames.
Unilateral Rail External Fixation
Unilateral frames are attached to the side of the bone and are mostly used for simple deformities and/or bone lengthening. They have limited capacity and capability compared with six-axis ring fixators, but they are smaller and more comfortable and render physical therapy easier.
Six-Axis External Ring Fixation
For correction of multiplanar deformities (deformity correction in more than one plane), six-axis external ring fixators can be used. They allow gradual correction in all planes of space and simultaneous bone lengthening. Complex software is used to calculate the settings of the rods and to create a prescription for daily adjustment of the frame. This process, combined with software-supported preoperative deformity planning and simulation, allows for precise deformity correction and exact anatomic results.
Guided Growth in Children
Genu varum (bowlegs) and genu valgum (knock-knees) can be easily corrected in the growing child, eliminating the need for more extensive surgery in adulthood. A small plate in a figure eight shape and two small screws, one above and one below the growth plate, are placed. The growth is thereby influenced in such a way that the deformity corrects itself over time.