HSS Journal

, Volume 6, Issue 2, pp 134–137 | Cite as

Failure of the Patellar Tendon with the Patella Everted versus Noneverted in a Matched-Pair Cadaver Model

  • James A. Ryan
  • Kathleen N. Meyers
  • Paolo DiBenedetto
  • Timothy M. Wright
  • Steven B. Haas
Original Article


Avoidance of patellar eversion during total knee arthroplasty may help to prevent injury to the patellar tendon. The purpose of this study was to compare the load-to-failure of the everted versus the noneverted patella in a cadaveric model. Fourteen cadaver knees (seven pairs) were loaded to failure with the patella everted in one knee and not everted in the other. Mean load-at-ultimate failure in the patella-everted group was 1,111 ± 572 N, and in the patella-noneverted group was 1,621 ± 683 N (p = 0.01). Additionally, loads-at-initial-partial failure were lower (p = 0.04) in the patella-everted compared to the patella-noneverted group, 573 ± 302 N versus 1,115 ± 358 N, respectively. A partial failure of the patellar tendon occurred in 100% of the everted specimens, whereas only 57% of the noneverted specimens had partial failure. These findings suggest patella eversion may lead to failure of the patellar insertion at lower loads than when the patella is not everted.


patellar eversion knee arthroplasty patellar tendon failure 


  1. 1.
    Insall J, A midline approach to the knee. J. Bone Jt. Surg. Am. 1971; 53: 1584–1586Google Scholar
  2. 2.
    Murray DG, Total knee arthroplasty. Clin. Orthop. Relat. Res. 1985; 192: 59–68PubMedGoogle Scholar
  3. 3.
    Lynch AF, Rorabeck CH, Bourne RB, Extensor mechanism complications following total knee arthroplasty. J. Arthroplast. 1987; 2(2): 135–140CrossRefGoogle Scholar
  4. 4.
    Bonutti PM, Mont MA, McMahon M, Minimally invasive total knee arthroplasty. J. Bone Jt. Surg. Am. 2004; 86: 26–32Google Scholar
  5. 5.
    Tria AJ, Coon TM, Minimal incision total knee arthroplasty: early experience. Clin. Orthop. Relat. Res. 2003; 416: 185–190CrossRefPubMedGoogle Scholar
  6. 6.
    Floren M, Davis J, Peterson MG, Laskin RS, A mini-midvastus capsular approach with patellar displacement decreases the prevalence of patella baja. J. Arthroplast. 2007; 22(6 Supple 2): 51–57CrossRefGoogle Scholar
  7. 7.
    Weale AE, Murray DW, Baines J, et al, Radiological changes five years after unicompartmental knee replacement. J. Bone Jt. Surg. Br. 2000; 82(7): 996–1000CrossRefGoogle Scholar
  8. 8.
    Weale AE, Murray DW, Newman JH, et al, The length of the patellar tendon after unicompartmental and total knee replacement. J. Bone Jt. Surg. Br. 1999; 81(5): 790–795CrossRefGoogle Scholar
  9. 9.
    Patel J, Reis MD, Bozic KJ, Extensor mechanism complications after total knee arthroplasty. Instr. Course Lect. 2008; 57: 283–294PubMedGoogle Scholar
  10. 10.
    Haas SB, Manitta MA, Burdick P, Minimally invasive total knee arthroplasty: the mini midvastus approach. Clin. Orthop. Relat. Res. 2006; 452: 112–116CrossRefPubMedGoogle Scholar
  11. 11.
    Haas SB, Cook S, Beksac B, Minimally invasive total knee replacement through a mini midvastus approach: a comparative study. Clin. Orthop. Relat. Res. 2004; (428): 68–73Google Scholar
  12. 12.
    Laskin RS, Beksac B, Phongjunakorn A, et al, Clin. Orthop. Relat. Res. 2004; (428): 74–81Google Scholar
  13. 13.
    Laskin RS, Minimally invasive total knee replacement using a mini-mid vastus incision technique and results. Surg. Technol. Int. 2004; 13: 231–238PubMedGoogle Scholar
  14. 14.
    Crossett LS, Sinha RK, Sechriest VF, et al, Reconstruction of a ruptured patellar tendon with Achilles tendon allograft following total knee arthroplasty. J. Bone Jt. Surg. Am. 2002; 84-A(8): 1354–1361Google Scholar
  15. 15.
    Park SS, Kubiak EN, Wasserman B, et al, Management of extensor mechanism disruptions occurring after total knee arthroplasty. Am. J. Orthop. 2005; 34(8): 365–372PubMedGoogle Scholar
  16. 16.
    Burnette RS, Berger RA, Della Valle CJ, et al, Extensor mechanism allograft reconstruction after total knee arthroplasty. J. Bone Jt. Surg. Am. 2005; 87 Suppl 1(Pt 2): 175–194Google Scholar

Copyright information

© Hospital for Special Surgery 2010

Authors and Affiliations

  • James A. Ryan
    • 1
  • Kathleen N. Meyers
    • 2
  • Paolo DiBenedetto
    • 3
  • Timothy M. Wright
    • 2
  • Steven B. Haas
    • 1
  1. 1.Department of Orthopaedic SurgeryHospital for Special SurgeryNew YorkUSA
  2. 2.Department of BiomechanicsHospital for Special SurgeryNew YorkUSA
  3. 3.Clinic of Orthopaedics and TraumatologyUniversity of Udine, AOU of UdineUdineItaly

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