Biodegradable semirigid plate and miniscrew fixation compared with rigid titanium fixation in experimental calvarial osteotomy

Abstract

No dislocation, instability, clinical foreign body reactions, infections, or loss of fixation were observed. Bone consolidation of the 2.35-mm-wide craniotomy lines was incomplete; connective tissue-filled defects through the bone were observed in 13 of 28 lines at 26 to 52 weeks. Statistical analyses based on histomorphometric studies showed no difference in consolidation with SR-PLLA miniscrew and titanium plate/screw fixation or between the two resorbable fixation methods. Fixation with rapidly degradable SR-PGA miniscrews resulted in less effective consolidation than on the contralateral titanium-treated side (p<0.05), but the bone segment was thicker (p<0.005). The SR-PGA miniscrews had disappeared by 6 weeks, the polyactide plate by 104 weeks, and the SR-PLLA miniscrews had been mostly resorbed at 104 weeks. Passive translocation of the titanium plates and screws into the bone tissue was seen at 52 and 104 weeks. In rapidly growing lamb frontal bone, comparable consolidation results, without complications, can be achieved with semi-rigid resorbable fixation compared with rigid metallic fixation.