In Vivo Determination of Cam-Post Engagement in Fixed and Mobile-bearing TKA
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Kinematics vary, sometimes in important ways, among the different types of total knee arthroplasty (TKA) designs, yet differences between the in vivo mechanisms of cam-post engagement in rotating-platform posterior-stabilized (PS) TKA, bicruciate-stabilized TKA, and fixed-bearing PS TKA designs remain largely uncharacterized.
The objective of this study was to determine the cam-post mechanism interaction for subjects implanted with three different TKA designs.
In vivo, analysis was conducted for patients implanted with nine rotating-platform PS TKAs, five knees with a fixed-bearing PS TKA, and 10 knees with a bicruciate-stabilized TKA while performing a deep knee bend. Three-dimensional kinematics of the implant components were determined by analysis of fluoroscopic images during flexion. The distances between the interacting surfaces were measured throughout flexion and instances and locations of contact were identified.
Seven of the 10 bicruciate-stabilized knees analyzed had the femoral component engaged with the anterior aspect of the tibial post at full extension. Posterior cam-post engagement occurred at 34° for the bicruciate-stabilized (range, 17°–68°), 93° for the fixed-bearing PS (range, 88°–100°), and at 97° (range, 90°–104°) for rotating-platform PS TKA. In bicruciate-stabilized and fixed-bearing PS knees, the contact initially occurred on the medial aspect of the posterior surface of the tibial post and then moved centrally and superiorly with increasing flexion. For rotating-platform PS TKA, it was located centrally on the posterior surface of the post at all times.
This study suggests that mobility of the polyethylene might play an important role in ensuring central cam-post interaction in PS TKA. The polyethylene insert rotates axially in accordance with the rotating femur, maintaining central cam-post contact. This phenomenon was not observed in the fixed-bearing PS TKAs analyzed in this study.
We speculate that this centralized symmetrical contact between the cam and posterior surface of the post could be beneficial clinically in terms of reducing wear of the posterior surface and particularly at the medial extremes of it.
Level of Evidence
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
- Argenson JN, Scuderi GR, Komistek RD, Scott WN, Kelly MA, Aubaniac JM. In vivo kinematic evaluation and design considerations related to high flexion in total knee arthroplasty. J Biomech. 2005;38:277–284. CrossRef
- Banks SA, Markovich GD, Hodge WA. In vivo kinematics of cruciate-retaining and -substituting knee arthroplasties. J Arthroplasty. 1997;12:297–304. CrossRef
- Catani F, Innocenti B, Belvedere C, Labey L, Ensini A, Leardini A. Articular contact estimation in TKA using in vivo kinematics and finite element analysis. Clin Orthop Relat Res. 2010;468:19–28. CrossRef
- Cates HE, Komistek RD, Mahfouz MR, Schmidt MA, Anderle M. In vivo comparison of knee kinematics for subjects having either a posterior stabilized or cruciate retaining high-flexion total knee arthroplasty. J Arthroplasty. 2008;23:1057–1067. CrossRef
- Dennis DA, Komistek RD, Colwell CE Jr, Ranawat CS, Scott RD, Thornhill TS, Lapp MA. In vivo anteroposterior femorotibial translation: a multi-center analysis. Clin Orthop Relat Res. 1998;356:47–57. CrossRef
- Dennis DA, Komistek RD, Mahfouz MR, Haas BD, Stiehl JB. Multicenter determination of in vivo kinematics after total knee arthroplasty. Clin Orthop Relat Res. 2003;416:37–57. CrossRef
- Dennis DA, Komistek RD, Scuderi GR, Zingde S. Factors affecting flexion after total knee arthroplasty. Clin Orthop Relat Res. 2007;464:53–60.
- Dennis DA, Mahfouz MR, Komistek RD, Hoff W. In vivo determination of normal and anterior cruciate ligament-deficient knee kinematics. J Biomech. 2005;38:241–253. CrossRef
- Fisher J, McEwen H, Tipper J, Jennings L, Farrar R, Stone M, Ingham E. Wear-simulation analysis of rotating-platform mobile-bearing knees. Orthopedics. 2006;29:S36–41.
- Fisher J, McEwen HM, Tipper JL, Galvin AL, Ingram J, Kamali A, Stone MH, Ingham E. Wear, debris, and biologic activity of cross-linked polyethylene in the knee: benefits and potential concerns. Clin Orthop Relat Res. 2004;428:114–119. CrossRef
- Haas BD, Komistek RD, Stiehl JB, Anderson DT, Northcut EJ. Kinematic comparison of posterior cruciate sacrifice versus substitution in a mobile bearing total knee arthroplasty. J Arthroplasty. 2002;17:685–692. CrossRef
- Kanekasu K, Banks SA, Honjo S, Nakata O, Kato H. Fluoroscopic analysis of knee arthroplasty kinematics during deep flexion kneeling. J Arthroplasty. 2004;19:998–1003. CrossRef
- Kim YH, Yoon SH, Kim JS. The long-term results of simultaneous fixed-bearing and mobile-bearing total knee replacements performed in the same patient. J Bone Joint Surg Br. 2007;89:1317–1323. CrossRef
- Komistek RD, Mahfouz MR, Bertin KC, Rosenberg A, Kennedy W. In vivo determination of total knee arthroplasty kinematics: a multicenter analysis of an asymmetrical posterior cruciate retaining total knee arthroplasty. J Arthroplasty. 2008;23:41–50. CrossRef
- Leszko F, Hovinga KR, Lerner AL, Komistek RD, Mahfouz MR. In vivo normal knee kinematics: is ethnicity or gender an influencing factor? Clin Orthop Relat Res. 2011;469:95–106. CrossRef
- Mahfouz MR, Hoff W, Komistek RD, Dennis DA. A robust method for registration of three-dimensional knee implant models to two-dimensional fluoroscopy images. IEEE Trans Med Imaging. 2003;22:1561–1574. CrossRef
- Mueller J, Komistek RD, Dennis DA. Kinematics of the implanted and non-implanted knee. In: Scott WN, ed. Insall & Scott Surgery of the Knee. 5th ed. Philadelphia, PA, USA: Churchill Livingstone; 2012.
- Pagnano MW, Trousdale RT, Stuart MJ, Hanssen AD, Jacofsky DJ. Rotating platform knees did not improve patellar tracking: a prospective, randomized study of 240 primary total knee arthroplasties. Clin Orthop Relat Res. 2004;428:221–227. CrossRef
- Post ZD, Matar WY, van de Leur T, Grossman EL, Austin MS. Mobile-bearing total knee arthroplasty: better than a fixed-bearing? J Arthroplasty. 2010;25:998–1003. CrossRef
- Ranawat AS, Rossi R, Loreti I, Rasquinha VJ, Rodriguez JA, Ranawat CS. Comparison of the PFC Sigma fixed-bearing and rotating-platform total knee arthroplasty in the same patient: short-term results. J Arthroplasty. 2004;19:35–39. CrossRef
- Ranawat CS, Komistek RD, Rodriguez JA, Dennis DA, Anderle M. In vivo kinematics for fixed and mobile-bearing posterior stabilized knee prostheses. Clin Orthop Relat Res. 2004;418:184–190. CrossRef
- Schmidt R, Komistek RD, Blaha JD, Penenberg BL, Maloney WJ. Fluoroscopic analyses of cruciate-retaining and medial pivot knee implants. Clin Orthop Relat Res. 2003;410:139–147. CrossRef
- Stiehl JB, Komistek RD, Dennis DA, Paxson RD, Hoff WA. Fluoroscopic analysis of kinematic after posterior-cruciate-retaining knee arthroplasty. J Bone Joint Surg Br. 1995;77:884–889.
- Suggs JF, Hanson GR, Park SE, Moynihan AL, Li G. Patient function after a posterior stabilized total knee arthroplasty: cam-post engagement and knee kinematics. Knee Surg Sports Traumatol Arthrosc. 2008;16:290–296. CrossRef
- Tamaki M, Tomita T, Watanabe T, Yamazaki T, Yoshikawa H, Sugamoto K. In vivo kinematic analysis of a high-flexion, posterior-stabilized, mobile-bearing knee prosthesis in deep knee bending motion. J Arthroplasty. 2009;24:972–978. CrossRef
- Victor J, Mueller JK, Komistek RD, Sharma A, Nadaud MC, Bellemans J. In vivo kinematics after a cruciate-substituting TKA. Clin Orthop Relat Res. 2010;468:807–814. CrossRef
- Wasielewski RC, Komistek RD, Zingde SM, Sheridan KC, Mahfouz MR. Lack of axial rotation in mobile-bearing knee designs. Clin Orthop Relat Res. 2008;466:2662–2668. CrossRef
- In Vivo Determination of Cam-Post Engagement in Fixed and Mobile-bearing TKA
Clinical Orthopaedics and Related Research®
Volume 472, Issue 1 , pp 254-262
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- 1. Center for Musculoskeletal Research, University of Tennessee, 301 Perkins Hall, Knoxville, TN, 37996, USA
- 2. DePuy Orthopaedics, Inc, Warsaw, IN, USA
- 3. Colorado Joint Replacement, Denver, CO, USA
- 4. Department of Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
- 5. The University of Colorado Health Sciences Center, Denver, CO, USA
- 6. Rocky Mountain Musculoskeletal Research Laboratory, Denver, CO, USA