Navigation in Multiligament Knee Reconstruction: A Proof-of-Concept Study on a Femoral Sawbones Model

Multiligament knee reconstruction surgery is technically challenging, requiring careful planning and execution. Accurate placement of bone tunnels is important for graft function and there is an inherent risk of tunnel collision, which can compromise graft integrity. In this proof-of-concept study, we present a technique using computer navigation to help optimize tunnel placement and to avoid collision during multiligament knee reconstruction. A computed tomography (CT)-based navigation system was used to plan and execute femoral tunnel placement on a Sawbones model, for a Schenck KD-IV multiligament knee reconstruction. After CT scanning of the Sawbones model, commercially available software was used to plan tunnel trajectories for reconstruction of the posterolateral corner, medial ligament complex, and both cruciate ligaments. Tunnel entry points and trajectories were based on bony landmarks as identified on CT. The model was successfully registered with an accuracy of <0.5 mm. Execution of tunnel drilling was carried out for 7 femoral tunnels, guided by computer navigation. A postprocedure CT scan was then performed and superimposed over the preoperative planning scan. This demonstrated excellent correlation between planned and executed tunnels with no evidence of tunnel collision. This study supports the idea of using computer navigation to plan and execute tunnels in multiligament knee reconstruction.