Ilizarov apparatus
Encyclopedia
The Ilizarov apparatus is named after the orthopedic surgeon Gavriil Abramovich Ilizarov from the Soviet Union, who pioneered the technique. It is used in surgical
procedures to lengthen or reshape limb bones; to treat complex and/or open bone fracture
s; and in cases of infected non-unions of bones that are not amenable with other techniques.
, then in the Soviet Union
. The procedure, and the first apparatus he designed for it, was inspired by a shaft bow
harness on a horse carriage (see photo to the right). Originally bicycle parts were used for the frame.
This novel technique was introduced to the West in the 1980s, predominantly via Italian surgeons. It gained popularity in the 1990s, and has been used successfully by many surgeons throughout the world. In most developing countries it is a highly specialised technique used mainly for deformity correction by experienced surgeons due to its complexity. Further development of the ring construct led to the Taylor Spatial Frame
which is more versatile and far easier to use, but very costly. Though nowadays intramedullary limb lengthening devices are also available, they are not suitable for deformity correction of bones.
(or titanium
) rings are fixed to the bone via stainless heavy-gauge wire (called "pins" or Kirschner wire
s). The rings are connected to each other with threaded rods attached through adjustable nuts. The circular construction and tensioned wires of the Ilizarov apparatus provide far more structural support than the traditional monolateral fixator system. This allows early weightbearing.
The top rings of the Ilizarov (fixed to the healthy bone by the tensioned wire) allow force to be transferred through the external frame (the vertical metal rods), bypassing the fracture site. Force is then transferred back to the healthy bone through the bottom ring and the tensioned wires. This allows the Ilizarov apparatus to act as a sort of bridge, both immobilizing the fracture site and relieving it of stress, while allowing for the movement of the entire limb and partial weight-bearing. Middle rings (and tensioned wires) act to hold the bone fragments in place and to give greater structural support to the apparatus and limb. However, the critical load bearing rings are the top and bottom rings which transfer the force from the healthy bone down to the healthy bone, bypassing the fracture site.
.
The procedure consists of an initial surgery, during which the bone is surgically fractured and the ring apparatus is attached. As the patient recovers, the fractured bone begins to grow together. While the bone is growing, the frame is adjusted by means of turning the nuts, thus increasing the space between two rings. As the rings are connected to opposite sides of the fracture, this adjustment, done four times a day, moves the now-healing fracture apart by approximately one millimeter per day. The incremental daily increases result in a considerable lengthening of the limb over time. Once the lengthening phase is complete, the apparatus stays on the limb for a consolidation period. The patient is able to fully weight bear on the Ilizarov frame, using crutches initially and pain is lessened. Once healing is complete, a second surgery is necessary to remove the ring apparatus. The result is a limb that is significantly longer. Additional surgery may be necessary, in the case of leg lengthening, to lengthen the Achilles tendon
to accommodate the longer bone length. The major advantage of this procedure is that because the apparatus provides complete support while the bone is recovering the patient can remain active aiding recovery.
A further use is of bone transport, whereby a defect in a long bone can be treated by transporting a segment of bone, whilst simultaneously lengthening regenerate to reduce the defect and finally dock with the other segment, producing a single bony unit.
While the Ilizarov apparatus is minimally invasive (no large incisions are made,) it is not free of complications. Pain is common and can be severe, but is treatable with analgesics. Careful attention to cleaning and hygiene is necessary to prevent pin site infection. Other complications include swelling, muscle transfixion, and joint contracture
s. Physical therapy is often indicated.
or cast) where there is a high risk of infection or the fracture is of such severity that internal fixators are unworkable.
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
procedures to lengthen or reshape limb bones; to treat complex and/or open bone fracture
Bone fracture
A bone fracture is a medical condition in which there is a break in the continuity of the bone...
s; and in cases of infected non-unions of bones that are not amenable with other techniques.
History
Professor Gavriil Abramovich Ilizarov invented this procedure in the 1950s after having to treat orthopedic conditions in the Kurgan region of SiberiaSiberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
, then in the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
. The procedure, and the first apparatus he designed for it, was inspired by a shaft bow
Shaft bow
A shaft bow is an element of horse harness that is attached to the front of the shafts of a horse-drawn vehicle and joins them by arching high above the neck of the horse. Use of the shaft bow is widespread in the area east of the Baltic Sea . A shaft bow is also used in traditional harness in...
harness on a horse carriage (see photo to the right). Originally bicycle parts were used for the frame.
This novel technique was introduced to the West in the 1980s, predominantly via Italian surgeons. It gained popularity in the 1990s, and has been used successfully by many surgeons throughout the world. In most developing countries it is a highly specialised technique used mainly for deformity correction by experienced surgeons due to its complexity. Further development of the ring construct led to the Taylor Spatial Frame
Taylor Spatial Frame
The Taylor Spatial Frame is an external fixator used by podiatric and orthopaedic surgeons to treat complex fractures and bone deformities. The medical device shares a number of components and features of the Ilizarov apparatus. The Taylor Spatial Frame is a hexapod device based on a Stewart...
which is more versatile and far easier to use, but very costly. Though nowadays intramedullary limb lengthening devices are also available, they are not suitable for deformity correction of bones.
Mechanics and physics
The device is a specialized form of external fixator, a circular fixator, modular in construction. Stainless steelStainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
(or titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
) rings are fixed to the bone via stainless heavy-gauge wire (called "pins" or Kirschner wire
Kirschner wire
Kirschner wires or K-wires or pins are sterilized, sharpened, smooth stainless steel pins. Introduced in 1909 by Martin Kirschner, the wires are now widely used in orthopaedics and other types of medical and veterinary surgery. They come in different sizes and are used to hold bone fragments...
s). The rings are connected to each other with threaded rods attached through adjustable nuts. The circular construction and tensioned wires of the Ilizarov apparatus provide far more structural support than the traditional monolateral fixator system. This allows early weightbearing.
The top rings of the Ilizarov (fixed to the healthy bone by the tensioned wire) allow force to be transferred through the external frame (the vertical metal rods), bypassing the fracture site. Force is then transferred back to the healthy bone through the bottom ring and the tensioned wires. This allows the Ilizarov apparatus to act as a sort of bridge, both immobilizing the fracture site and relieving it of stress, while allowing for the movement of the entire limb and partial weight-bearing. Middle rings (and tensioned wires) act to hold the bone fragments in place and to give greater structural support to the apparatus and limb. However, the critical load bearing rings are the top and bottom rings which transfer the force from the healthy bone down to the healthy bone, bypassing the fracture site.
Bone lengthening/reshaping
In addition to being used to support a fractured limb, the Ilizarov frame is also commonly used to correct deformity through distraction osteogenesisDistraction osteogenesis
Distraction osteogenesis, also called callus distraction, callotasis and osteodistraction is a surgical process used to reconstruct skeletal deformities and lengthen the long bones of the body...
.
The procedure consists of an initial surgery, during which the bone is surgically fractured and the ring apparatus is attached. As the patient recovers, the fractured bone begins to grow together. While the bone is growing, the frame is adjusted by means of turning the nuts, thus increasing the space between two rings. As the rings are connected to opposite sides of the fracture, this adjustment, done four times a day, moves the now-healing fracture apart by approximately one millimeter per day. The incremental daily increases result in a considerable lengthening of the limb over time. Once the lengthening phase is complete, the apparatus stays on the limb for a consolidation period. The patient is able to fully weight bear on the Ilizarov frame, using crutches initially and pain is lessened. Once healing is complete, a second surgery is necessary to remove the ring apparatus. The result is a limb that is significantly longer. Additional surgery may be necessary, in the case of leg lengthening, to lengthen the Achilles tendon
Achilles tendon
The Achilles tendon , also known as the calcaneal tendon or the tendo calcaneus, is a tendon of the posterior leg. It serves to attach the plantaris, gastrocnemius and soleus muscles to the calcaneus bone.- Anatomy :The Achilles is the tendonous extension of 3 muscles in the lower leg:...
to accommodate the longer bone length. The major advantage of this procedure is that because the apparatus provides complete support while the bone is recovering the patient can remain active aiding recovery.
A further use is of bone transport, whereby a defect in a long bone can be treated by transporting a segment of bone, whilst simultaneously lengthening regenerate to reduce the defect and finally dock with the other segment, producing a single bony unit.
While the Ilizarov apparatus is minimally invasive (no large incisions are made,) it is not free of complications. Pain is common and can be severe, but is treatable with analgesics. Careful attention to cleaning and hygiene is necessary to prevent pin site infection. Other complications include swelling, muscle transfixion, and joint contracture
Contracture
A muscle contracture is a permanent shortening of a muscle or joint.. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy....
s. Physical therapy is often indicated.
Bone fracture treatment
The Ilizarov method is widely used to treat complex and/or open bone fractures. This method is preferred over conventional treatment options (such as internal fixatorInternal fixator
Internal fixation is an operation in orthopedics that involves the surgical implementation of implants for the purpose of repairing a bone, a concept that dates to the mid-19th century...
or cast) where there is a high risk of infection or the fracture is of such severity that internal fixators are unworkable.
Images
The following case study illustrates the Ilizarov apparatus treatment procedure for a fractured limb. The photographs are of the same patient during the course of treatment.See also
- Bone healingBone healingBone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture....
- Fibrocartilage callusFibrocartilage callusA fibrocartilage callus is a temporary formation of fibroblasts and chondroblasts which forms at the area of a bone fracture as the bone attempts to heal itself...
- OsteoporosisOsteoporosisOsteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
- Stress fractureStress fractureA stress fracture is one type of incomplete fracture in bones. It is caused by "unusual or repeated stress" and also heavy continuous weight on the ankle or leg...
- Blowout fractureBlowout fractureA blowout fracture is a fracture of the walls or floor of the orbit. Intraorbital material may be pushed out into one of the paranasal sinuses. This is most commonly caused by blunt trauma of the head, generally personal altercations...
- Distraction osteogenesisDistraction osteogenesisDistraction osteogenesis, also called callus distraction, callotasis and osteodistraction is a surgical process used to reconstruct skeletal deformities and lengthen the long bones of the body...
- Osteogenesis ImperfectaOsteogenesis imperfectaOsteogenesis imperfecta is a genetic bone disorder. People with OI are born with defective connective tissue, or without the ability to make it, usually because of a deficiency of Type-I collagen...
- PseudarthrosisPseudarthrosisPseudarthrosis is the movement of a bone at the location of a fracture resulting from inadequate healing of the fracture.Pseudarthrosis can also result from a developmental failure.-Etymology:...
External links
- Dr. Dror Paley Informational site (Ortho conditions section includes video of Ilizarov methods) .
- Living with an Ilizarov/Taylor Spatial Frame UK newspaper article
- ilizarov.com (English)
- The ILIZAROV frame wearer's support group
- More information and pictures about the Ilizarov surgical technique
- Institute for Limb Lengthening and Reconstruction
- Taylor Spatial Frame
- Legs lengthening and correction with Ilizarov frame
- Providing excellent case summaries for Ilizarov treatment of complex fractures, including X-rays