Self-Made Distal Femoral Extramedullary Positioning Osteotomy Template In Total Knee Arthroplasty

Abstract Introduction: The objective of this study was to assess the success of total knee arthroplasty with the use of extramedullary positioning osteotomy templates for limb alignment in contrast to traditional intramedullary positioning rods. Methods: Between September 2019 and February 2021, 70 participants underwent total knee arthroplasty with lower limb positioning using an extramedullary distal femur positioning template and intramedullary positioning rods. The participants were divided into two groups each to receive either of the two limb positioning techniques. The groups were divided randomly and were similar at the beginning of the study. Therefore, the participants were equally divided into 35 participants per group. Participants' indication for the procedure was severe osteomyelitis or rheumatoid arthritis, and they underwent distal femoral osteotomy. The force lines of the lower limb were identified by locating the center of the head of the femur. The patients were monitored for intraoperative bleeding, surgical trauma and surgical time. They were followed up during the first and second weeks post-operation to assess for knee joint movement graded using the HSS knee score and assessed for deviation. Participants were treated equally throughout the study and during the follow-up phase. Results: The participants did not have any statistically significant differences at the beginning of the study. The intramedullary group had a lesser average age but without any significant difference from the extramedullary group. In addition, their HSS knee scores, body mass index, knee joint range of motion, and the angle of deviation of the knee, hip, and ankle were of no statistical significance with a p-value of more than 0.05. The operation time for the extramedullary group was approximately 96.57 minutes with a margin of error of (+/-) 8.576 minutes. In contrast, the intramedullary group had an average time of 104.8 minutes and a margin of error of (+/-) 8.864. Intraoperative bleeding for the extramedullary group was less at approximately 89.97 ml, while it was 95.4ml in the intramedullary group. Postoperative drainage was also more in the intramedullary group as compared to the intramedullary group. The differences between both groups were statistically significant, with a p-value of less than 0.05. There was no significant difference in HKA angle deviation, coronal plane angle, and flexion angle of femoral prosthesis (P > 0.05). Conclusion: Extramedullary distal femoral osteotomy positioning templates proved superior to intramedullary positioning rods. The template demonstrated less surgical trauma hence the lower risk of deformity, less intraoperative bleeding, therefore, more safety and less risk for infection than the intramedullary positioning rods.