Abstract
Background
The symmetry and equality of the flexion and extension gap are essential for successful endoprosthetic knee arthroplasty. Cruciate ligament sparing endoprosthetic designs are implanted with a measured resection technique, so that the posterior bone resection corresponds to the posterior condyle thickness. However, this correlation only applies if the sagittal alignment is set at 0°. The aim of the present study was therefore to investigate the extent to which the flexion gap is influenced by a flexed implantation of the femoral component.
Methods
The implant geometry of all available sizes of the knee systems Columbus, e.motion (Aesculap), PFC Sigma (DePuy), Natural Knee II, Innex, Nexgen LPS Flex and Gender (Zimmer), and TC Plus (Smith & Nephew) was recorded. Based on this data, a virtual implantation of the femoral component with a sagittal alignment between 0° and 5° of flexion was simulated. The resulting flexion gaps were calculated depending on the component alignment. The relationships between component alignment (in degrees) and flexion gap (in mm) were documented for every implant.
Results
The narrowing of the flexion gap with increasing flexion was more or less linear in the range investigated and was dependent on the system used and the implant size. A narrowing of the flexion gap by 1 mm resulted from 2° (1.9°–2.3°) flexion in the e.motion prosthesis, 1.9° (1.6°–2.4°) in the Columbus, 1.6° (1.5°–1.8°) in the PFC Sigma, 2.0° (1.7°–2.4°) in the Nexgen LPS Flex and Gender, 1.7° (1.6°–1.8°) in the Innex, 2.2° (1.5°–2.6°) in the TC Plus and 2.0° (2.0°–2.1°) in the Natural Knee.
Conclusions
Even a small flexion of the femoral component leads to a reduction of the flexion gap and thus potentially to limited mobility in the measured resection technique. On the other hand, in navigation-assisted implantation, slight flexion of the component can possibly be used to adjust the flexion gap smoothly.
Level of evidence
II.
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References
Arima J, Whiteside LA, Martin JW, Miura H, White SE, McCarthy DS (1998) Effect of partial release of the posterior cruciate ligament in total knee arthroplasty. Clin Orthop Relat Res 353:194–202
Chung BJ, Kang YG, Chang CB, Kim SJ, Kim TK (2009) Differences between sagittal femoral mechanical and distal reference axes should be considered in navigated TKA. Clin Orthop Relat Res 467:2403–2413
Gejo R, Morita Y, Matsushita I, Sugimori K, Kimura T (2008) Joint gap changes with patellar tendon strain and patellar position during TKA. Clin Orthop Relat Res 466:946–951
Hamai S, Miura H, Higaki H, Shimoto T, Matsuda S, Iwamoto Y (2008) Evaluation of impingement of the anterior tibial post during gait in a posteriorly-stabilised total knee replacement. J Bone Joint Surg Br 90:1180–1185
Hanson GR, Suggs JF, Kwon YM, Freiberg AA, Li G (2007) In vivo anterior tibial post contact after posterior stabilizing total knee arthroplasty. J Orthop Res 25:1447–1453
Howell SM, Kuznik K, Hull ML, Siston RA (2008) Results of an initial experience with custom-fit positioning total knee arthroplasty in a series of 48 patients. Orthopedics 31:857–863
Long WJ, Scuderi GR (2008) High-flexion total knee arthroplasty. J Arthroplasty 23(7 Suppl):6–10
Longstaff LM, Sloan K, Stamp N, Scaddan M, Beaver R (2009) Good alignment after total knee arthroplasty leads to faster rehabilitation and better function. J Arthroplasty 24:570–578
Matsumoto T, Muratsu H, Kubo S, Mizuno K, Kinoshita K, Ishida K, Matsushita T, Sasaki K, Tei K, Takayama K, Sasaki H, Oka S, Kurosaka M, Kuroda R (2011) Soft tissue balance measurement in minimal incision surgery compared to conventional total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 19:880–886
Matziolis G, Krocker D, Weiss U, Tohtz S, Perka C (2007) A prospective, randomized study of computer-assisted and conventional total knee arthroplasty. Three-dimensional evaluation of implant alignment and rotation. J Bone Joint Surg Am 89:236–243
Merican AM, Ghosh KM, Iranpour F, Deehan DJ, Amis AA (2011) The effect of femoral component rotation on the kinematics of the tibiofemoral and patellofemoral joints after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 19:1479–1487
Minoda Y, Kobayashi A, Iwaki H, Ohashi H, Takaoka K (2009) TKA sagittal alignment with navigation systems and conventional techniques vary only a few degrees. Clin Orthop Relat Res 467:1000–1006
Ritter MA, Faris PM, Keating EM (1988) Posterior cruciate ligament balancing during total knee arthroplasty. J Arthroplasty 3:323–326
Spencer BA, Mont MA, McGrath MS, Boyd B, Mitrick MF (2009) Initial experience with custom-fit total knee replacement: intra-operative events and long-leg coronal alignment. Int Orthop 33:1571–1575
Swany MR, Scott RD (1993) Posterior polyethylene wear in posterior cruciate ligament-retaining total knee arthroplasty. A case study. J Arthroplasty 8:439–446
Yamakado K, Worland RL, Jessup DE, Diaz-Borjon E, Pinilla R (2003) Tight posterior cruciate ligament in posterior cruciate-retaining total knee arthroplasty: a cause of posteromedial subluxation of the femur. J Arthroplasty 18:570–574
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Matziolis, G., Hube, R., Perka, C. et al. Increased flexion position of the femoral component reduces the flexion gap in total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 20, 1092–1096 (2012). https://doi.org/10.1007/s00167-011-1704-9
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DOI: https://doi.org/10.1007/s00167-011-1704-9