A method of internal fracture fixation using rod‐shaped biodegradable implants made of self‐reinforced polyglycolic acid (PGA) is described. These biodegradable implants were employed in the fixation of fractures in a metaphysis and diaphysis. The fractures healed clinically and radiolo‐gically in six weeks without complicatons. The patients started to use the operated limbs during the first postoperative week and lameness disappeared within six weeks. Biodegradable fixation devices will be a useful tool in the treatment of fractures in veterinary surgery.

The Finnish group led by Rokkanen and Tormala has developed a biodegradable implant for fracture fixation. Results from experimental and clinical studies of polyglycolic acid (PGA) are encouraging, and further studies are being made in the use the biorod, which has been used successfully to treat an avulsed calcaneal fracture in a puppy. Other biodegradable substances are being investigated to improve biodegradable fracture fixation devices.

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.

The frequent need for removal of metallic implants after fracture healing, has stimulated research into biodegradable osteosynthesis materials. The ideal biodegradable implant should support the fracture during healing and would slowly lose strength as the bone became able to resist the distracting forces. Decades of research into biodegradable materials has given much information on biocompatibility, degradation rates and processability of resorbable polyglycolides and polylactides. This has aided the development of an ultra high strength self‐reinforcing composite construction allowing the manufacture of implants for several purposes. This study tested the use of self‐reinforced poly‐1‐lactic acid rods for the fixation of cancellous fractures and osteotomies in 20 fixations in dogs and cats. The operating technique, callus formation, healing pattern, and functional and radiological end result, were evaluated. Two fixations failed but the functional end result was judged to be excellent in all but one of the healed cases. There was no need for surgery to remove the implants.

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