Ultra-high-strength absorbable self-reinforced polyglycolide (SR-PGA) composite rods for internal fixation of bone fractures: in vitro and in vivo study.

The ultra-high-strength, self-reinforced (SR) absorbable polymeric composites, consisting of reinforcement elements, like fibers, and of matrix polymer which have the same chemical element composition as reinforcement, were defined. A method to manufacture self-reinforced, absorbable polyglycolide (SR-PGA) rods of polyglycolide sutures (Dexon) by sintering them partially together at elevated temperature and pressure was presented. The rods with nominal diameters of 1.5 mm, 2.0 mm, 3.2 mm, and 4.5 mm showed initial bending modulus and strength values of 8-15 GPa and 220-405 MPa, respectively. Their initial shear strengths were 165-255 MPa. The smallest rods (diam. 1.5 mm) lost their mechanical strength after implantation in the subcutis of rabbits in 4-5 weeks while the thickest rods retained their strength over 8 weeks. The ultra-high-strength SR-PGA rods were concluded to be suitable for fixation of cancellous bone fractures, osteotomies, and epiphyseal plate fractures where the fixation is not exposed to excessive mechanical stresses and where the loads are predominantly of a shear nature.

[1]  B. Gay,et al.  [Animal experiment studies on the use of absorbable polydioxanone (PDS) screws in osteosynthesis]. , 1985, Der Unfallchirurg.

[2]  L. Claes,et al.  [Resorbable implants for refixation of osteochondral fragments in joint surfaces]. , 1986, Aktuelle Traumatologie.

[3]  J. Merendino,et al.  Use of Biocompatible Orthopaedic Polymer for Fracture Treatment and Reconstructive Orthopaedic Procedures , 1984, The Journal of international medical research.

[4]  P. Törmälä,et al.  The effects of fibre reinforcement and gold plating on the flexural and tensile strength of PGA/PLA copolymer materials in vitro. , 1987, Biomaterials.

[5]  P. Paavolainen,et al.  Structural changes in intact tubular bone after application of rigid plates with and without compression. , 1978, The Journal of bone and joint surgery. American volume.

[6]  H. Alexander,et al.  DEVELOPMENT OF A VARIABLE STIFFNESS, ABSORBABLE BONE PLATE , 1979 .

[7]  P. Knauß,et al.  Materialkennwerte und Festigkeitsverhalten des spongiösen Knochengewebes am coxalen Human-Femur - Material Properties and Strength Behaviour of Spongy Bone Tissue at the Coxal Human Femur , 1981 .

[8]  Fred Leonard,et al.  Polylactic Acid for Surgical Implants , 1966 .

[9]  D E Cutright,et al.  The repair of fractures of the orbital floor using biodegradable polylactic acid. , 1972, Oral surgery, oral medicine, and oral pathology.

[10]  Donnie F. Williams.  Enzymic Hydrolysis of Polylactic Acid , 1981 .

[11]  P. Törmälä,et al.  Surgical applications of biodegradable polymers in human tissues , 1989 .

[12]  M. Mayor,et al.  The biocompatibility of materials for internal fixation of fractures. , 1978, Journal of biomedical materials research.

[13]  C. W. Dunn.  A favour or favourite , 1984 .

[14]  H. Uhthoff,et al.  Influence of stable fixation on trabecular bone healing: A morphologic assessment in dogs , 1987, Journal of Orthopaedic Research.

[15]  N. Langrana,et al.  Development of new methods for phalangeal fracture fixation. , 1981, Journal of biomechanics.

[16]  O. Böstman,et al.  Transphyseal fracture fixation using biodegradable pins. , 1989, The Journal of bone and joint surgery. British volume.

[17]  F Leonard,et al.  Biodegradable poly(lactic acid) polymers. , 1971, Journal of biomedical materials research.

[18]  S. Swanson.  Biomechanical Characteristics of Bone , 1971 .

[19]  N R Gjerdet,et al.  Effect of instability of experimental fracture healing. , 1982, Acta orthopaedica Scandinavica.

[20]  H. Kawahara,et al.  Single crystal alumina for dental implants and bone screws. , 1980, Journal of biomedical materials research.

[21]  P. Törmälä,et al.  Absorption, biocompatibility, and fixation properties of polylactic acid in bone tissue: an experimental study in rats. , 1991, Clinical orthopaedics and related research.

[22]  C L Davidson,et al.  Protection from stress in bone and its effects. Experiments with stainless steel and plastic plates in dogs. , 1976, The Journal of bone and joint surgery. British volume.

[23]  H. Uhthoff,et al.  Bone structure changes in the dog under rigid internal fixation. , 1971, Clinical orthopaedics and related research.

[24]  O. Böstman,et al.  Ankle fractures treated using biodegradable internal fixation. , 1989, Clinical orthopaedics and related research.