Intramedullary nailing of diaphyseal fractures with self‐reinforced polylactide implants

Abstract

In fracture treatment, several adverse effects of metal, especially its excessive rigidity, often require the removal of the implants after a fracture has healed. Recent research with biodegradable polymers has contributed to the development of totally biodegradable polylactic acid implants with very high initial bending and shear strengths, but a modulus of elasticity comparable to that of bone. These implants were originally intended for use in fractures involving cancellous bone. Encouraging results from treating experimentally produced diaphyseal fractures led the authors to use these implants in a clinical trial on shaft fractures in dogs and cats. In this study, a total of 11 dogs and 14 cats had 28 diaphyseal fractures treated with one or several intramedullary pins of self‐reinforced left isomeric polylactic acid. Of the 25 treated cases, 23 healed. Four of these had an unsatisfactory end result attributed to the implants used and one developed an osteomyelitis. Thus, out of 25 fractures, 23 united (92 per cent] and 18 [72 per cent) had a good or excellent outcome.

Fabrication of a biodegradable calcium polyphosphate/polyvinyl‐urethane carbonate composite for high load bearing osteosynthesis applications

“…As an alternative to metallic devices, a fair body of research has been conducted on the use of biodegradable polymeric fixation devices. 2,[9][10][11][12][13][14][15][16][17][18][19][20] Such polymeric devices have elastic constants below that of cortical bone but unfortunately are also not stiff enough or strong enough 5,21 to be used in major load bearing applications. The availability of a high strength fully biodegradable fracture fixation device for use in major load bearing applications where metallic devices are currently used would offer the advantage of a single surgical procedure avoiding the need for a second surgery for device removal.…”

“…Attempts to form PFCs with higher vol % CPP proved difficult due to particle clustering and problems in achieving good particle distribution. 27 Although the FRC structures provided higher stiffness in one direction (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) GPa bending elastic constant for 50 vol % samples; higher volume fractions were difficult to produce while maintaining an even fiber distribution), the composite was highly anisotropic and displayed poor machining characteristics. 27 Although complex lamellar designs and fabrication processes could be potentially used to overcome this limitation, this was not pursued in view of the relatively straightforward procedures developed for forming IPC structures with E Bending $ 20-40 GPa.…”

“…As an alternative to metallic devices, a fair body of research has been conducted on the use of biodegradable polymeric fixation devices 2, 9–20. Such polymeric devices have elastic constants below that of cortical bone but unfortunately are also not stiff enough or strong enough5, 21 to be used in major load bearing applications.…”

Repair of Radial Fractures in Toy Breed Dogs with Self‐Reinforced Biodegradable Bone Plates, Metal Screws, and Light‐Weight External Coaptation

“…The self‐reinforced (SR) structure of biodegradable implants, where a matrix is reinforced by fibers of the same substance, has enabled production of devices that have initial strength values comparable with that of steel 5 . Intramedullary nails and pins made of self‐reinforced poly‐ l ‐lactide (SR‐PLLA) have been successfully used for repair of osteotomies of the femoral diaphysis in adult rabbits and sheep, and also clinically, in repair of cancellous and diaphyseal fractures in dogs and cats 6‐9 …”

Humeral fracture treatment in pigeons by bone pins made from ovine and canine bones

“…Flight is an important activity in birds, and any disruption or inability to fly endangers the bird's life. PLLA (Poly-L-Lactic acid) isomer has been used for thigh bone fracture repair in rabbits and in femoral fracture in cats and dogs [17]. The PLLA is hydrolyzed in the first four to five months and converted to lactic acid [14].…”