Anteromedial Tibial Tunnel Research Articles

Tibial Cyst and Intra-Articular Granuloma Formation After Anterior Cruciate Ligament Reconstruction Using Polylactide Carbonate Osteoconductive Interference Screws

We report a case of sterile tibial cyst and intra-articular granuloma formation of the knee 6 months after a double-bundle anterior cruciate ligament reconstruction with bioabsorbable polylactide carbonate osteoconductive interference screws. The patient presented with increasing pain and swelling of the knee. Surgical exploration was performed, and 2 pretibial cavities were encountered, filled with remnants of the biodegradable screws and fibrinous material. Both sites underwent curettage, and the cavities were filled with allogeneic bone grafts. Arthroscopic evaluation of the knee showed an intact anterior cruciate ligament and a large granuloma formation anterior to the intercondylar notch in conjunction with the anteromedial tibial tunnel. Arthroscopic resection of the granuloma together with synovectomy was performed. To our knowledge, this is the first case report of this complication with polylactide carbonate screws.

Double-Bundle “Anatomic” Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Tunnel Positioning With a Transtibial Technique

The aim of this study was to examine whether a double-bundle anterior cruciate ligament (ACL) reconstruction with a transtibial approach could position the tibial and femoral tunnels accurately in the native bundle attachments. In 21 fresh-frozen knees the tibial and femoral attachments of the anteromedial (AM) and posterolateral (PL) bundles were outlined. The AM tibial tunnel guidewire was drilled with the 65 degree Howell tibial guide (Arthrotek, Warsaw, IN) located against the femur in the extended knee. The PL tibial wire was drilled through a prototype attachment to the Howell guide. Of the knees, 14 were available for the femoral part of the study. The AM femoral guidewire used an aimer offset 3 mm from the over-the-top position. The PL wire was drilled transtibially at 70 degrees of flexion, with external rotation and posterior drawer loads being applied. The plateaus and condyles were photographed and the wire positions measured. With regard to the tibia, 17 of 21 AM wires were in the AM bundle attachment (at 61% and 36% of the natural ACL posteroanterior and mediolateral length, respectively) and 19 of 21 PL wires were in the PL bundle attachment (at 28% and 36% of the posteroanterior and mediolateral length, respectively). With regard to the femur, 12 of 14 AM wires and 9 of 14 PL wires were in the correct native bundle attachment. The AM wire was 3% more shallow than the center of the AM attachment (P = .03) and 6% more superior (P < .001), where 100% was the diameter of the posterior lateral condyle. The PL wire was 4% more shallow than the center of the PL attachment (P = .026) and 6% more superior (P < .001). Anatomic and reproducible tibial guidewire positioning was achieved. Femoral wires were reproducibly positioned, but both were superior to and more shallow than the natural ACL bundle attachments, so further development or a different approach is appropriate. The double-bundle reconstruction aims to restore anterior drawer and rotational stability. This technique ensures anatomic tibial positioning. Further improvements are needed with regard to the femur.