Computed Tomography Imaging of BioComposite Interference Screw After ACL Reconstruction With Bone-Patellar...

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Regenerative Medicine

Background:

• Bioabsorbable interference screws for anterior cruciate ligament (ACL) reconstruction often resorb quickly.
• No prior studies evaluated the resorption and bone replacement of 30% biphasic calcium phosphate and 70% poly-d-lactide (30% BCP/70% PLDLA) screws.

Purpose of the Study:

• To assess femoral and tibial tunnel widening and screw resorption of 30% BCP/70% PLDLA interference screws.
• To evaluate bone replacement of these screws 2-5 years post-ACL reconstruction using bone-patellar tendon-bone (BTB) autograft.

Main Methods:

• A case series of 20 patients undergoing ACL reconstruction with BTB autograft.
• Computed tomography (CT) scans were used to measure tunnel dimensions and assess screw resorption and bone formation at 2-5 years post-surgery.
• Paired t-tests compared initial and final tunnel measurements.

Main Results:

• Femoral and tibial tunnel cross-sectional areas decreased significantly post-operatively.
• Complete screw resorption was observed in the femur (100%) and tibia (94.7%).
• Bone formation occurred in 100% of femoral and 94.7% of tibial tunnels, with minimal cyst formation (5.1% in femur).

Conclusions:

• 30% BCP/70% PLDLA interference screws demonstrate high resorption and bone replacement after ACL reconstruction.
• No adverse increase in tunnel size was observed at 2-5 years post-surgery.
• This screw type is a safe and effective option for graft fixation in ACL reconstruction.