PLDLA/BCP BioComPoSite. inteRfeRenCe SCRewS. +. BioDegRADABLe PLLA. inteRfeRenCe SCRewS in Anterior Cruciate Ligament Reconstruction Surgery ...
Prospective, Randomized Study comparing
Biodegradable PLLA Interference Screws
+
PLDLA/BCP BioComposite Interference Screws
in Anterior Cruciate Ligament Reconstruction Surgery: Magnetic Resonance Imaging, Computer Tomography Preliminary Results and Clinical Outcome C. Koidl, R. El-Attal, V. Smekal, G. Degenhart, C. Kranewitter – Innsbruck Medical University, Austria
Background Ligament graft fixation with bioabsorbable interference screws in cruciate ligament replacement has increased in the last decade. The rate of resorption and osteoconductive properties has been the focus of numerous studies. The modified composition of the BioComposite interference screw * should lead to a higher rate of resorption and osteoconductivity.
Hypothesis Poly-L-lactide acid (PLLA) interference screws would show the same clinical results but a significantly lower rate of resorption and osteoconductivity leading to more tunnel widening than BioComposite (biphasic calcium phosphate (BCP) / poly (L-lactide-co-D, L-lactide) (PLDLA) interference screws 2 years after anterior cruciate ligament reconstruction using hamstring tendon (semitendinosus / gracilis) autografts.
STUDY DESIGN Randomized controlled trial; Level of evidence, 1
The two interference screws used in this study: The BioComposite interference screw* (30 % biphasic calcium phosphate (hydroxyapatite and ß-tricalcium phosphate in a 60:40 ratio) and 70 % Poly (L-lactide-co-D-lactide) (PLDLA)
The PLLA (Poly L-Lactide Acid) interference screw*
METHODS A randomized series of 15 patients, all with a unilateral anterior cruciate ligament rupture, were divided into 2 groups (PLLA and BioComposite*) In both groups, hamstring tendon autografts were used with interference screw fixation at both ends and it was a 2-year follow-up with magnetic resonance imaging (at 1 week, 3, 6 12 and 24 months), computer tomography (at 1 week and 24 months), Tegner activity level, Lysholm knee score, Marshall score and IKDC.
RESULTS We evaluated 11 male and 4 female patients at a mean of 24 months after surgery (range, 24 to 26 months). Eight of those patients were randomized to the BioComposite group and 7 patients to the PLLA group. The CT scans show a bone tunnel enlargement of 5.8 ± 10.84 % in the tibia and 36.1 ± 53.5 % in the femur (P = 0.04) for the BioComposite group and 16.3 ± 19.6 % in the tibia and 19.05 ± 37.6 % in the femur for the PLLA group. The MRI scans show a screw volume loss of 467.6 to 278.4 mm³ in the femur (P
