The document discusses factors that influence range of motion (ROM) after total knee arthroplasty (TKA), including patient factors like obesity, surgical technique, and prosthetic design. It finds that posterior stabilized (PS) designs can provide higher ROM than posterior cruciate retaining designs, and that the LPS High Flex PS design further increases ROM, with reported passive flexion of 130-140 degrees in many cases. However, it also notes there may be increased risks of wear, synovitis, and anterior knee pain with such high flexion.

1. Design Factors Influencing Range of Motion in TKA James B. Stiehl, MD Medical College of Wisconsin Milwaukee, Wisconsin

9. LCSPS Design Flaws

11. LPS Design Considerations Longer Cam; Posterior Condyle 2mm > LPS High Flex LPS

12. Patellar Impingement Impingement LPS LPS High Flex

14. Literature Review: PS vs PS Flex <.05 135  120  50 Weeden, et.al. =0.41 138  135  50* Kim, et.al. <.05 138  126  50 Huang, et.al. <.05 129  124  180 Bin, et.al. SD PS High Flex PS N Author

17. LPS High Flex Mobile Results 150 ° Passive Flexion

18. LPS High Flexion Sitting 9 Inch Stool, >135 ° Flexion

19. LPS High Flex- Down Stairs

20. LCS Versus LPS High Flex in Passive Flexion Left- LPS High Flex- 115  Right- LCS - 105 

25. Detrimental Kinematics Of A Flat on Flat Condylar TKA Stiehl, CORR, 1999 Medial Condyle Lateral Condyle

26. LPS High Flex on Stairs

28. LPS High Flex Walking

29. LCS PS Mobile Bearing TKA