Dr. Masuda was interviewed on November 18, 2021. He is affiliated with UCSD as a Professor of Orthopedic Surgery. Dr. Masuda’s work has given him experience working with ACL skeletal research in the rabbit model.

Some of the general guidance he provided us was to use specific key terms, including “repair”, when conducting literature searches to find relevant information. He also stressed how working in a rabbit model requires a focus on anatomy since rabbit knees do not experience full extension like humans. When asked about the type of graft, Dr. Masuda advised using a semitendinosus autograft graft since it is the easiest to work with.

Prior to creating questions for the interview, the team reviewed the interviews conducted last year. One suggestion Dr. Masuda made for the previous interview was to perform the knee anterior drawer test at 20 degrees. When asked about the rationale behind this, he explained that human drawer tests are typically performed at this flexion angle. Using a degree closer to 90 degrees has a capsule, holding the knee in tension during the test. It was also recommended to fix both sides of the knee when testing while allowing free movement in the 6 degrees of freedom.

Imaging using microCT is an integral part of evaluating the success of the ACL reconstruction. It is also used in our method to determine the placement of bone tunnels. When asked about targeting bone drilling positions using imaging, Dr. Masuda suggested we place a marker in 4 distinct locations. The tibia should be pulled taut with a screw to produce a better quality image. Once the image is produced, the distance between the anterior and posterior ends of the tibia should be measured. From there, the point should be identified using the metal screw. Dr. Masuda also let us know that he is able to supply us with some rabbit knees in December.

Alborz was interviewed on October 25, 2021. He is a PhD candidate in the Cartilage Tissue Engineering lab. Alborz has worked with rabbit models and the surgical procedures that are required for our project oftenly with his research.

When asked whether we should use an autograft or allograft for the reconstruction, Alborz advised there is some literature evidence supporting both types. He also mentioned that we look into hamstring or patellar tendon patellar bone grafts. For biomechanical tests, he recommended to emphasize knee laxity testing. Knee laxity tests provide answers on how well anterior shift is being restored, but they do not comment on the quality or tensile strength of the graft. The graft strength can be tested by pulling the graft under tension until failure. Stiffness testing requires tensile testing of the ligament, which can occur in the form of load or displacement control. Displacement control is when the ligaments from both sides are held and stretched up to 5mm before measuring the force build-up. Load control is when load, in the form of 25N, is placed on the ligament and identifying how much displacement occurs. Of these tests, knee laxity testing and anterior shift is the most crucial because it has a large signal relative to the tibia and femur.

The imaging performed should identify the knee anatomy with contrast, including the ACL structure. From this image, the orientation of the ACL can be determined along with the 3D view of the tibial and femoral insertion points. For general advice, he suggested having well-defined aims to guide the project and to complete goals in parallel by delegating tasks.