Healing of physeal fracture after fixation with biodegradable self-reinforced polyglycolic acid pins.  An experimental study on growing rabbits.
Physeal fractures occur at a frequency of 15% of all long bone fractures in children.  Undisturbed continued bone growth is the main goal of the treatment of these fractures.  After the operative reduction and fixation, whenever needed, a second operation for the removal of the pins is inevitable.  The purpose of this study was to develop a biodegradable fixation device for transphyseal fracture fixation, abolishing the need of removal operation. Epiphyseal separation of the distal femoral physis was made on the right side in 18 five-week-old rabbits.  The fixation of the physeal fracture was made with two self-reinforced polyglycolic acid (SR-PGA) pins 1mm in nominal diameter and 25mm in length. The follow-up times were 3, 6, 12, 24, and 28 weeks.  The distal femoral growth-plate of both femurs was analyzed by radiographic, microradiographic, oxytetracycline-fluorescence, histological and histomorphometric studies. Histomorphometric studies showed normal features of growth.  Two growth-plate-penetrating transcondylar SR-PGA implants, of 1mm in diameter, provided sufficient stability for the fixation of a distal femoral physeal fracture in a growing rabbit, and did not cause any growth disturbance.
Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Finland.
E A
EA
Mäkelä
S
S
Vainionpää
K
K
Vihtonen
M
M
Mero
J
J
Laiho
P
P
Törmälä
P
P
Rokkanen
D000818:Animals; D001673:Biodegradation, Environmental; D001858:Bone Nails; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005264:Femoral Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006132:Growth Plate / Q000033:anatomy & histology; D011100:Polyglycolic Acid; D011817:Rabbits