Tri-Medics, based in Foxboro, MA, specified Radel polyphenylsulfone (PPSU) from plastics supplier Solvay Advanced Polymers LLC (Atlanta, GA) for the device. According to Tri-Medics this is the first time plastic has been used for a fully adjustable positioning support for orthopedic trauma surgery. The 30-cm (12-in) long sides of the triangle are injection molded by General Pattern (Blaine, MN).
The Bender triangle can be adjusted to fit the patient helping to simplify surgery and decrease operating room time, according to Bradley Bender, Tri-Medics president and inventor of the patented device. It is an effective alternative to more costly and complicated fixed positioning supports made of foam rubber and metal. "This one-of-kind device gives surgeons a broader view as well as greater control and precision," said Bender.
Radel PPSU offers the high strength required during intramedullary (IM) nailing of the femur and tibia and other manipulative actions. The device is used for universal positioning for IM nailing, plating, and external fixation applications. The Bender consists of three injection molded adjustable sides that form a triangular structure, or as a single unit for a starting point during IM nailing of the tibia. The triangle can be configured to any angle or height as a unit or segmented for hyper-flexion and optimal exposure, giving a surgeon an unlimited range of adjustments for positioning the patient's extremities.
Radel PPSU also offers chemical resistance and withstands repeated autoclaving - up to 1000 cycles - while maintaining its toughness and impact resistance. The material is a transparent thermoplastic with a heat distortion temperature (HDT) of 207°C (405°F).
The Bender triangle - which consists of three sides and three pivot corners - is made entirely of Radel PPSU, except for six stainless steel nuts, according to designer Jeffrey Kapec, co-principal and executive vice president of Tanaka Kapec Design Group (Norwalk, CT), an industrial design and product development firm. The four-pound device slides together and is assembled with pins made of Radel PPSU.
Other thermoplastics considered for the triangle were polyetherimide (PEI), polyetheretherketone (PEEK), and polycarbonate (PC), but PPSU offered the best combination of attributes for this device. Tri-Medics sells the Bender adjustable positioning triangle nationally to surgeons and hospitals.