Memory of DL-polylactic acid biodegradable plates.
Biodegradable plates and screws have many advantages over metal plates and screws. Plates were injection-molded and made of DL-polylactic acid. Four-hole plates were bent with the use of a heated tip to angles of 30, 45, and 60 degrees. They were inserted in the subcutaneous space in the back of rabbits. After 2 weeks, the plates straightened, suggesting that the plates had a memory. The results were confirmed by similar in vitro investigations. The in vitro experiment was repeated with tempering of the plates. The plates were heated to a temperature of 200 degrees C for 45 seconds, cooled, and then again heated to 200 degrees C for 40 seconds. This process resulted in loss of memory of the plates. After 4 weeks, there was a change of the bending angle of less than 2.5 degrees.
Losken
H W
HW
Division of Plastic and Reconstructive Surgery, University of Pittsburgh, PA.
Tschakaloff
A
A
von Oepen
R
R
Mooney
M P
MP
Moritz
O
O
Michaeli
W
W
Lalikos
J
J
Losken
A
A
D000818:Animals; D001673:Biodegradation, Environmental; D001860:Bone Plates; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007773:Lactates; D019344:Lactic Acid; D008970:Molecular Weight; D011091:Polyesters; D011108:Polymers; D011817:Rabbits
D007773:Lactates; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)