Joint Arthroplasty: Fixation

The JVL Research Center is recognized internationally for major contributions to the understanding of implant fixation. The researchers developed the first composite synthetic femur for biomechanical testing in the 1980’s, now widely available.

Current Research

Over the last few years, various aspects of implant design and fixation have been evaluated using custom load simulators. Some of the questions that have been addressed have been:

  • What is the relative influence of proximal stem geometry on initial fixation?
  • What is the influence of cement thickness on fixation?
  • How much proximal bone is required to achieve stable fixation?
  • What is the optimal surface finish for a cemented femoral stem?



  1. Ebramzadeh, E., Sangiorgio, S.N., Longjohn, D.B., Buhari, C.F., Dorr, L.D. “Initial stability of cemented femoral stems as a function of surface finish, collars, and stem size.” J Bone and Joint Surg, Am, 2004. Jan;86-A (1): 106-115.
  2. Sangiorgio, S.N., Ebramzadeh, E., Longjohn, D.B., Dorr, L.D. “Effects of Dorsal Flanges on Fixation of a Cemented Total Hip Replacement Femoral Stem.” J Bone Joint Surg Am. 2004 Apr; 86(4):813-820.\
  3. Sangiorgio, S.N., Longjohn, D.B., Lee, J.L., Alexander, J.D., Dorr, L.D., Ebramzadeh,E. “Simulation of extreme loads on the proximal femur for implant fixation assessment.” J Appl Biomat and Biomech, 2008; 6(2):72:80.
  4. Bengs, B. C., Sangiorgio, S.N., Ebramzadeh, E. “Less range of motion for resurfacing arthroplasty than with total hip arthroplasty: in vitro examination of 8 designs.” Acta Orthop. 2008; 79(6):755-62.
  5. Sangiorgio, S.N., Longjohn, D.B., Dorr, L.D. Ebramzadeh, E.: “The influence of proximal stem geometry and surface finish on the fixation of a double-tapered cemented femoral stem.” J Biomech 2011 Jan 4;44(1):22-7.
  6. Sangiorgio, S.N., Longjohn, D.B., Dorr, L.D. Ebramzadeh, E.: “Challenges in relating experimental hip implant fixation predictions to clinical observations.” J Biomech 2011; Jan 11;44(2):235-43.
  7. Sangiorgio, SN, Ebramzadeh, E, Knutsen, AR, Borkowski, SL, Kalma, JJ, Bengs, BC: “Fixation of Non-Cemented Total Hip Arthroplasty Femoral Components in a Simulated Proximal Bone Defect Model,” Journal of Arthroplasty, 2013 Oct; 28(9):1618-24.23.