Evaluation of the effect of transphyseal bioabsorbable screws on growth of rabbit femur

A self-reinforced bioabsorbable poly-L-lactide/polyglycolide (SR-PLGA) 80/20 screw 2.0 mm in diameter was implanted in a transphyseal location across the distal growth plate of the right femur in 24 immature rabbits. Radiological evaluation revealed a mean shortening of 3.1 mm at 3 weeks (p=0.050), 11.1 mm at 6 weeks (p=0.001), 9.3 mm at 24 weeks (p=0.011), 9.0 mm at 48 weeks (p=0.009) and 12.6 mm at 72 weeks (p=0.002) compared with the intact contralateral femur. Growth retardation continued for 6 weeks postoperatively (3 versus 6 weeks, p=0.003), after which the bones grew normally up to 72 weeks (p=0.6). The duration of temporary growth retardation correlated with that of strength retention of the SR-PLGA 80/20 copolymer. These findings suggest that SR-PLGA 80/20 screws can be applied in transphyseal bone fixation. The use of bioabsorbable screws for temporary epiphyseodesis seems attractive but requires further study.