The Taylor Spatial Frame (TSF) is an

external fixator External fixation is a surgical treatment wherein rods are screwed into bone and exit the body to be attached to a stabilizing structure on the outside of the body. It is an alternative to internal fixation, where the components used to provide st ...

used by

paediatric Pediatrics ( also spelled ''paediatrics'' or ''pædiatrics'') is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, paediatrics covers many of their youth until the ...

and

orthopaedic surgeon Orthopedic surgery or orthopedics ( alternatively spelt orthopaedics), is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal ...

s to treat complex fractures and bone deformities. The medical device shares a number of components and features of the

Ilizarov apparatus In medicine, the Ilizarov apparatus is a type of external fixation apparatus used in orthopedic surgery to lengthen or to reshape the damaged bones of an arm or a leg; used as a limb-sparing technique for treating complex fractures and open bone ...

. The Taylor Spatial Frame is a hexapod device based on a

Stewart platform A Stewart platform is a type of parallel manipulator that has six prismatic actuators, commonly hydraulic jacks or electric linear actuators, attached in pairs to three positions on the platform's baseplate, crossing over to three mounting po ...

, and was invented by orthopaedic surgeon Charles Taylor. The device consists of two or more

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

carbon fibre Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

rings connected by six

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. Human anatomy Part of the functionality o ...

s. Each strut can be independently lengthened or shortened to achieve the desired result, e.g. compression at the fracture site, lengthening, etc. Connected to a bone by tensioned wires or half pins, the attached bone can be manipulated in three dimensions and 9 degrees of freedom. Angular, translational, rotational, and length deformities can all be corrected simultaneously with the TSF. The TSF is used in both adults and children. It is used for the treatment of acute

fracture Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

s, mal-unions, non-unions and

congenital A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

deformities. It can be used on both the upper and lower limbs. Specialised foot rings (which are not seen in the picture) are also available for the treatment of complex foot deformities.

Post Operative procedure

Correcting deformities

Once the fixator is attached to the bone, the deformity is characterised by studying the postoperative

x-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s, or CT scans. The angular, translational,

rotational Rotation, or spin, is the circular movement of an object around a '' central axis''. A two-dimensional rotating object has only one possible central axis and can rotate in either a clockwise or counterclockwise direction. A three-dimensional ...

, and length deformity values are then entered into specialised software, along with mounting parameters and hardware parameters such as the ring size and initial strut lengths. The software then produces a "prescription" of strut changes that the patient follows. The struts are adjusted daily by the patient until the correct alignment is achieved. Correction of the bone deformity can typically take 3–4 weeks. For simpler fractures where no deformity is present the struts may still be adjusted post-surgery to achieve better bone alignment, but the correction takes less time. For individuals performing strut adjustment. a hand mirror may be useful to aid in reading the strut settings. Once the deformity has been corrected, the frame is then left on the limb until the bone fully heals. This often takes 3–6 months, depending on the nature and degree of deformity.

Dynamisation

When the bone has sufficiently healed, the frame can be dynamised. This is a process of gradually reducing the supportive role of the frame by reducing the length stability. This causes force that was previously transmitted around the fracture site and through the struts to be transmitted through the bone.

Removal of frame

After a period of dynamisation, the frame can be removed. This is a relatively simple procedure often performed under gas and air analgesic. The rings are removed by cutting the olive wires using wire cutters. The wires are then removed by first sterilising them and then pulling them through the leg using pliers. The threaded half pins are simply unscrewed.

Use for fractures

External fixation via TSFs tends to be less invasive than

internal fixation 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-nineteenth century and was made applicable for routine treatment in the m ...

and therefore has lower risks of infection associated with it. This is particularly relevant for open fractures. For open comminuted fractures of the

tibial plateau Tibial may refer to: * Tibia bone * Tibial nerve * Anterior tibial artery * Posterior tibial artery * Anterior tibial vein * Posterior tibial vein The posterior tibial veins are veins of the leg in humans. They drain the posterior compartment o ...

the use of circular frames (like TSF) has markedly reduced infection rates. The time taken for bones to heal (time to union) varies depending on a number of factors. Open fractures take longer to heal, and infection will delay union. For tibial fractures union is generally achieved after between 3 and 6 months, though time to union can be rather subjective, and the dynamistion process combined with irregular appointments may interfere with these measures.

Infection

Infection of the pin sites (points where wires enter the skin) of the TSF is a common complication (estimates are that it affects 20% percent of patients). In extreme cases this can result in

osteomylitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

which is difficult to treat. However, pin site infections are normally successfully treated with a combination of oral antibiotics,

intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

antibiotics, or removal of the affected pin. Pin sites are classified as

percutaneous {{More citations needed, date=January 2021 In surgery, a percutaneous procedurei.e. Granger et al., 2012 is any medical procedure or method where access to inner organs or other tissue is done via needle-puncture of the skin, rather than by using ...

wounds Best practice for maintenance of pin sites is unclear and requires more study. Common practice involves the regular cleaning of the pin sites with

chlorhexidine gluconate Chlorhexidine (CHX) (commonly known by the salt forms chlorhexidine gluconate and chlorhexidine digluconate (CHG) or chlorhexidine acetate) is a disinfectant and antiseptic that is used for skin disinfection before surgery and to sterilize surgi ...

solution (advice varies from every day to every week), regular showering, and dressing of sites that exude liquid with non-woven gauze soaked in chlorhexidine gluconate. This dressing can be held in place with bungs or makeshift clips or by twisting around the wire. Advice varies as to whether scab tissue or any "crust" surrounding a pin site should be maintained. With some literature arguing that this acts as a barrier to entry, while other literature argues this may increase the risk of infection.

Cost of treatment

The taylor spatial frame is a general tool for fixating and moving bone fragments in a gradual way. This means that costs can vary dramatically. The cost of a frame itself was around 2,500 pounds sterling in 2006 though this cost will vary depending on the number of components in the frame. Cases involving treatment of nonunion of fracture are complicated and time-consuming with costs of around 30,000 pounds sterling in 2006 and treatment can take between 1 and 2 years. Of these costs about 23,000 pound sterling reflect follow-up outpatient treatment and cost for hospital stays, which can vary dramatically between patients.

References

External links

Information on Taylor Spatial Frame (TSF), design, geometry, advantages and limitations
{{Webarchive, url=https://web.archive.org/web/20160406055332/http://www.bonefixator.com/fracture_fixation/taylor_spatial_frame_1.html , date=2016-04-06
Smart Correction Application for Hexapod Fixator with Radiographic Navigation Software
Orthopedic surgical procedures Orthopaedic instruments