The evaluation of the distance between the popliteus tendon and the lateral collateral ligament footprint and the implant in Total Knee Arthroplasty using a 3-dimensional template.

Abstract

Background When surgeons perform TKA, popliteus tendon (PT) and lateral collateral ligament (LCL) iatrogenic injuries are a risk because the femoral attachments are relatively close to the bone resection area. The purpose of this study was to evaluate the distance between the PT or LCL footprint and the TKA implant using a 3D template system and to evaluate any significant differences according to the implant model. Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used. All the surrounding soft tissue except the PT, ligaments and meniscus were removed from the knee. Careful dissection of the PT and LCL was performed, and the femoral footprints were detected. Each footprint periphery was marked with a K-wire. CT scanning was then performed. The data was analyzed with a 3D template system. This simulation models for TKA were the Journey II BCS and the Persona PS. The area of each footprint, and the length between the most distal and posterior point of the lateral femoral condyle and the edge of each footprint were measured. Matching the implant model to the CT image, the shortest length between each footprint and the osteotomy area were calculated. Results The area of the PT and LCL footprints was 38.7±17.7mm 2 and 58.0±24.6mm 2 . The length between the most distal and posterior point of the lateral femoral condyle and the edge of the PT footprint was 10.3±2.4mm and 14.2±2.8mm. The length between these same points and the edge of the LCL footprint was 16.3±2.3mm and 15.5±3.3mm. Under TKA simulation, for the Journey II BCS and the Persona PS, the shortest length between the PT footprint and the osteotomy area was 4.3±2.5mm and 3.2±2.9mm, and the shortest length between the LCL footprint and the osteotomy area was 7.2±2.3mm and 5.6±2.1mm. The PT attachment was damaged by the bone resection of the Journey II BCS and the Persona PS TKA in 3 and 9 knee. Conclusion The PT and LCL femoral attachments existed close to the femoral bone resection area of the TKA. Careful attention is needed to avoid damage to the PT and LCL during surgical procedures.