Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 25, Issue 12, pp 3695–3703 | Cite as

Comparison of the efficiency of an extra-articular absorber system and high tibial osteotomy for unloading the medial knee compartment: an in vitro study

  • Gerrit BodeEmail author
  • Ferdinand Kloos
  • Matthias J. Feucht
  • Benjamin Fleischer
  • Norbert Südkamp
  • Philipp Niemeyer
  • Christoph Becher



The unloading effect of an extra-articular absorber system on the knee joint medial compartment was compared with high tibial osteotomy (HTO) under physiological conditions in vitro.


Seven fresh-frozen cadaveric knees were used to test isokinetic flexion–extension motions under physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment. Pressures were measured after KineSpring System implantation and HTO (5° and 10° correction angles) performed with an angular-stable internal fixator (Tomofix).


Implantation of the unloading device resulted in significantly decreased medial compartment area contact pressure (Δ0.02 ± 0.01 MPa, p = 0.001) and peak contact pressure (Δ0.3 ± 0.1 MPa, p = 0.001) compared with the first test cycle results in the untreated knee. HTO significantly decreased the pressure (p = 0.001). Compared with the first test cycle, HTO (5° correction angle) decreased the mean contact pressure by Δ0.03 ± 0.01 MPa and peak contact pressure by Δ0.3 ± 0.01 MPa. With a 10° correction angle, HTO decreased contact pressure by Δ0.04 ± 0.02 MPa and peak contact pressure by Δ0.4 ± 0.1 MPa compared with that at the 5° correction angle.


Implantation of an extra-capsular unloading device resulted in a significant unloading effect on the medial compartment comparable to that achieved with HTO at 5° and 10° correction angles. Thus, implantation of an extra-articular, extra-capsular absorber could become the method of choice when treating patients with unicompartmental osteoarthritis that cannot be adequately treated by HTO because of their straight-leg axis.


Unicompartmental osteoarthritis Unloading Osteotomy Medial compartment 



Funding was provided by Müller-Fahnenberg Stiftung.

Conflict of interest

None of the authors has any conflict of interest.


The study was funded by the Müller-Fahnenberg Study of Freiburg University.

Ethical approval

The ethics committee of Hannover University approved this study (ID 3083-2016).


  1. 1.
    Agneskirchner JD, Hurschler C, Stukenborg-Colsman C et al (2004) Effect of high tibial flexion osteotomy on cartilage pressure and joint kinematics: a biomechanical study in human cadaveric knees. Winner of the AGA-DonJoy Award 2004. Arch Orthop Trauma Surg 124(9):575–584CrossRefPubMedGoogle Scholar
  2. 2.
    Becher C, Heyse TJ, Kron N et al (2009) Posterior stabilized TKA reduce patellofemoral contact pressure compared with cruciate retaining TKA in vitro. Knee Surg Sports Traumatol Arthrosc 17(10):1159–1165CrossRefPubMedGoogle Scholar
  3. 3.
    Block JA, Shakoor N (2009) The biomechanics of osteoarthritis: implications for therapy. Curr Rheumatol Rep 11(1):15–22CrossRefPubMedGoogle Scholar
  4. 4.
    Bode G, Ogon P, Pestka J et al (2015) Clinical outcome and return to work following single-stage combined autologous chondrocyte implantation and high tibial osteotomy. Int Orthop 39(4):689–696CrossRefPubMedGoogle Scholar
  5. 5.
    Bode G, Schmal H, Pestka JM et al (2013) A non-randomized controlled clinical trial on autologous chondrocyte implantation (ACI) in cartilage defects of the medial femoral condyle with or without high tibial osteotomy in patients with varus deformity of less than 5 degrees. Arch Orthop Trauma Surg 133(1):43–49CrossRefPubMedGoogle Scholar
  6. 6.
    Bode G, von Heyden J, Pestka J et al (2015) Prospective 5-year survival rate data following open-wedge valgus high tibial osteotomy. Knee Surg Sports Traumatol Arthrosc 23(7):1949–1955CrossRefPubMedGoogle Scholar
  7. 7.
    Brandt KD, Dieppe P, Radin E (2009) Etiopathogenesis of osteoarthritis. Med Clin North Am 93(1):1–24, xvGoogle Scholar
  8. 8.
    Brandt KD, Dieppe P, Radin EL (2009) Commentary: is it useful to subset “primary” osteoarthritis? A critique based on evidence regarding the etiopathogenesis of osteoarthritis. Semin Arthritis Rheum 39(2):81–95CrossRefPubMedGoogle Scholar
  9. 9.
    Clifford A, O’Connell M, Gabriel S et al (2011) The KineSpring load absorber implant: rationale, design and biomechanical characterization. J Med Eng Technol 35(1):65–71CrossRefPubMedGoogle Scholar
  10. 10.
    Clifford AG, Gabriel SM, O’Connell M et al (2013) The KineSpring((R)) Knee Implant System: an implantable joint-unloading prosthesis for treatment of medial knee osteoarthritis. Med Devices 6:69–76Google Scholar
  11. 11.
    Floerkemeier S, Staubli AE, Schroeter S et al (2013) Outcome after high tibial open-wedge osteotomy: a retrospective evaluation of 533 patients. Knee Surg Sports Traumatol Arthrosc 21(1):170–180CrossRefPubMedGoogle Scholar
  12. 12.
    Intema F, Van Roermund PM, Marijnissen AC et al (2011) Tissue structure modification in knee osteoarthritis by use of joint distraction: an open 1-year pilot study. Ann Rheum Dis 70(8):1441–1446CrossRefPubMedPubMedCentralGoogle Scholar
  13. 13.
    Kajiwara R, Ishida O, Kawasaki K et al (2005) Effective repair of a fresh osteochondral defect in the rabbit knee joint by articulated joint distraction following subchondral drilling. J Orthop Res 23(4):909–915CrossRefPubMedGoogle Scholar
  14. 14.
    Lobenhoffer P, Agneskirchner J, Zoch W (2004) Open valgus alignment osteotomy of the proximal tibia with fixation by medial plate fixator. Orthopade 33(2):153–160CrossRefPubMedGoogle Scholar
  15. 15.
    Lobenhoffer P, Agneskirchner JD (2003) Improvements in surgical technique of valgus high tibial osteotomy. Knee Surg Sports Traumatol Arthrosc 11(3):132–138CrossRefPubMedGoogle Scholar
  16. 16.
    Lutzner J, Gross AF, Gunther KP et al (2010) Precision of navigated and conventional open-wedge high tibial osteotomy in a cadaver study. Eur J Med Res 15(3):117–120CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Messier SP, DeVita P, Cowan RE et al (2005) Do older adults with knee osteoarthritis place greater loads on the knee during gait? A preliminary study. Arch Phys Med Rehabil 86(4):703–709CrossRefPubMedGoogle Scholar
  18. 18.
    Messier SP, Gutekunst DJ, Davis C et al (2005) Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis. Arthritis Rheum 52(7):2026–2032CrossRefPubMedGoogle Scholar
  19. 19.
    Minzlaff P, Feucht MJ, Saier T et al (2016) Can young and active patients participate in sports after osteochondral autologous transfer combined with valgus high tibial osteotomy? Knee Surg Sports Traumatol Arthrosc 24(5):1594–1600CrossRefPubMedGoogle Scholar
  20. 20.
    Niemeyer P, Schmal H, Hauschild O et al (2010) Open-wedge osteotomy using an internal plate fixator in patients with medial-compartment gonarthritis and varus malalignment: 3-year results with regard to preoperative arthroscopic and radiographic findings. Arthroscopy 26(12):1607–1616CrossRefPubMedGoogle Scholar
  21. 21.
    Reising K, Strohm PC, Hauschild O et al (2013) Computer-assisted navigation for the intraoperative assessment of lower limb alignment in high tibial osteotomy can avoid outliers compared with the conventional technique. Knee Surg Sports Traumatol Arthrosc 21(1):181–188CrossRefPubMedGoogle Scholar
  22. 22.
    Staubli AE, De Simoni C, Babst R et al (2003) TomoFix: a new LCP-concept for open wedge osteotomy of the medial proximal tibia—early results in 92 cases. Injury 34(Suppl 2):B55–B62CrossRefPubMedGoogle Scholar
  23. 23.
    Stiebel M, Miller LE, Block JE (2014) Post-traumatic knee osteoarthritis in the young patient: therapeutic dilemmas and emerging technologies Open Access. J Sports Med 5:73–79Google Scholar
  24. 24.
    W-Dahl a, Robertsson O (2016) Similar outcome for total knee arthroplasty after previous high tibial osteotomy and for total knee arthroplasty as the first measure. Acta Orthop. doi: 10.1080/17453674.2016.1195663:1-6 PubMedPubMedCentralGoogle Scholar
  25. 25.
    W-Dahl a, Robertsson O, Lohmander LS (2012) High tibial osteotomy in Sweden, 1998–2007: a population-based study of the use and rate of revision to knee arthroplasty. Acta Orthop 83(3):244–248CrossRefPubMedPubMedCentralGoogle Scholar
  26. 26.
    Waller C, Hayes D, Block JE et al (2011) Unload it: the key to the treatment of knee osteoarthritis. Knee Surg Sports Traumatol Arthrosc 19(11):1823–1829CrossRefPubMedGoogle Scholar
  27. 27.
    Ziegler R, Goebel L, Seidel R et al (2015) Effect of open wedge high tibial osteotomy on the lateral tibiofemoral compartment in sheep. Part III: analysis of the microstructure of the subchondral bone and correlations with the articular cartilage and meniscus. Knee Surg Sports Traumatol Arthrosc 23(9):2704–2714CrossRefPubMedGoogle Scholar

Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2016

Authors and Affiliations

  1. 1.Department of Orthopedic Surgery and Traumatology, Clinic of Orthopedic Surgery and TraumatologyFreiburg University HospitalFreiburgGermany
  2. 2.Department of Orthopedic SurgeryHannover Medical SchoolHannoverGermany

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