The effect of therapeutic irradiation on LactoSorb absorbable copolymer.
Bioabsorbable implants continue to gain popularity in providing temporary internal fixation due to their many advantages over metallic internal fixation. Coincident with the presence of internal fixation devices, it may be necessary to use radiotherapy to treat tumors. While metal implants can alter the distribution of the radiotherapy beam, bioabsorbable polymer implants are, essentially, tissue equivalent. This ionizing irradiation, in sufficiently high dose, can affect polymers through chain scission and cross-linking and accelerate the hydrolysis of absorbable polymers. However, little is known about the effects of therapeutic doses on such materials. This study exposed LactoSorb (Biomet, Inc., Warsaw, IN) absorbable copolymer to doses of x-ray irradiation in a clinically relevant manner, in vitro, with individual doses of 2 Gy administered five days per week for up to eight weeks, yielding a total cumulative dose of up to 80 Gy. Specimens were tested both mechanically and for inherent viscosity. Overall, the LactoSorb specimens withstood exposure to the irradiation exceedingly well, providing empirical evidence of the suitability of this material for temporary internal fixation when subsequent radiotherapy in the region is probable.
Biomet, Inc., Warsaw, Indiana, USA.
William S
WS
Pietrzak
Maritza
M
Gamboa
Ketan
K
Patel
Dushyant
D
Sharma
Mukesh
M
Kumar
Barry L
BL
Eppley
D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry / Q000528:radiation effects*; D002725:Chloroform / Q000737:chemistry; D019583:Dose Fractionation, Radiation; D004548:Elasticity; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry / Q000528:radiation effects*; D009984:Orthopedic Fixation Devices; D018583:Pliability; D011100:Polyglycolic Acid / Q000737:chemistry / Q000528:radiation effects*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects*; D011878:Radiotherapy; D012997:Solvents / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D014783:Viscosity
D001672:Biocompatible Materials; D011108:Polymers; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D002725:Chloroform