Optimal Entry Position On The Lateral Tibial Surface For Outside-in Drilling Technique To Restore The Anatomical Insertion Of PCL

Objective: we evaluated the relationship between the tangent of posterior tibial corteX and tibial plateau through the plane angle between the tangent and the posterior cruciate ligament tibial insertion made by keen X ray,and provide a feasible and safety angle range clinically for Transtibial technique.Methods:1 198 patients with X-ray of standard keen positive side were selected,including 91 males and 107 females with average age of 34.5±8.61 years old.2 using picture achieving and communication system(PACS)to confirm posterior cruciate ligament tibial insertion center,and made a double parallel linear model simulate of tibial tunnel,the distance between the lower tangent and posterior tibial edge was kept 2mm.The angle between lower tangent and tibial plateau was taken to be the maXimum safety angle of tunnel and tibial plateau.The upper tangent and tibial node was taken to be the position of the entrance of tibial tunnel,and the distance between bitial tubercles and this point was measured.3 Two attending doctors of orthopedics doctors measured each angle and distance respectively.The angle value and distance between tibial tunnel entrance edge and tibial plateau for man and woman were compared.Results:1 Male,female and total measurement values were consistent with normal distribution.2 The maXimum safety average angle was 64.2±5.3°.95% of male,female and total cases were located in 52°~75°,and there was no difference in gender.The total average between upper margin of the tunnel and tibial tubercles was 8.34±0.82,and there was statistical significance between the male and female.Overall 95% was in the range 6.90-9.67 cm,95% in 7.03-9.74 cm for man and 6.86-9.67 cm for woman.Men had 95% larger than 7.42 cm,women had 7.04 cm,total was 7.20 cm,there was statistically significant between men and women.Conclusion:1 The safe and feasible range for the angle between tibial tunnel and tibial plateau was 52°~75° calculated by keen X-ray lateral position.2 When the distance of upper edge of tunnel to tibial plateau picture was smaller than 7.42 cm for man and 7.04 cm for woman,it was considered to be safe.