Anatomical Tibial Tunnel Vector in Pull-Out Repair for a Medial Meniscal Posterior Root Tear (MMPRT) and Its Clinical Potential

Introduction This study focuses on the tibial tunnel in the pull-out repair of medial meniscus posterior root tears (MMPRTs), with attention to the distal hole as the anatomical vector. Little research has explored this aspect, as previous studies have mainly emphasized the proximal hole as the attachment point. Methods The anatomical vector was identified by analyzing magnetic resonance images of 84 healthy knees. Clinical nine cases that underwent pull-out repair using the anatomical tibial tunnel (AT) with open wedge high tibial osteotomy (OWHTO) were evaluated to investigate the interference between plate screws and AT, and longitudinal changes in tibial tunnel diameter. Results Almost all distal holes of the tibial tunnels were plotted on the anterolateral surface of the tibia. The distal hole of the anatomical vector was more lateral in the 'body mass index of more than 22 kg/m2' and 'currently with sports' groups. In only one clinical case, the AT interfered with the proximal anterior screw. The tibial tunnel diameter was significantly reduced in the AT group compared with the medial tibial tunnel (MT). Conclusions The anatomical vector pointed to the anterolateral surface of the tibia and tended to point outward due to potential overload. Compared with the MT, the AT is expected to reduce the killer turn of the posterior root, promoting early tibial tunnel filling, and improving interference issues with screws in OWHTO. The AT can be an option for pull-out repair of MMPRTs.