Serial Magnetic Resonance Imaging Evaluation of Bioabsorbable Interference Screws in Anterior Cruciate Ligament Reconstruction

Lee, Kwang Won; Ahn, Tae Gyoo; Han, Tae Il; Choy, Won Sik

Abstract

PURPOSE: To evaluate the changes at the postoperative site of anterior cruciate ligament (ACL) reconstruction, in which bioabsorbable screws were used for fixation, by magnetic resonance imaging (MRI) and to evaluate the efficacy and safety of Bioscrews(R) (Linvatec, Largo, FL).
MATERIALS AND METHODS
This prospective study was initiated in May 1997 upon 38 patients receiving Bioscrews(R). All patients with arthroscopically assisted primary reconstruction of ACL involving fixation with Bioscrews were examined 3, 6, 12 and 24 months after operation by Lysholm score, KT-2000 arthrometer and MRI. MR Images were interpreted by musculoskeletal radiologists.
RESULTS
There were no complications related to loss of fixation. The Lysholm scores and the KT- 2000 arthrometer measurement at final follow-up were 95.6 and 1.8 mm respectively. Even after two years there was evidence of screw material in all cases. MRIs taken at 3 months showed fluid collections inside the tibial tunnel (n=3) and the anterior aspect of the tibial tunnel (n=1), Though these fluid collections disappeared gradually. Varying amounts of edma were observed around the tunnels. We divided the bone edema into the ring (n=5) and diffuse types (n=16), which disappeared gradually.
CONCLUSION
The Bioscrews(R) was found to be a safe and effective alternative for fixation in ACL reconstruction, but requires the long term follow-up to confirm its safety.