International Orthopaedics

, Volume 36, Issue 11, pp 2395–2395 | Cite as

Can we always trust in the computer? Adequate tibial alignment and flexion-gap balancing using personalised knee arthroplasty cutting blocks

  • Norbert Kastner
  • Gerald Gruber
  • Patrick SadoghiEmail author
Letter to the Editor


Total Knee Arthroplasty Cutting Block Knee Surgeon Tibial Alignment Individualise Cutting 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

To the Editor,

Patient-individualised cutting blocks have drowned the market of total knee arthroplasty (TKA), promising not only faster but even easier surgical success after adequate planning [1, 2, 3, 4]. The authors want to discuss how to adequately achieve and improve tibial alignment and flexion gap balancing using the patient individualised TruMatch total knee arthroplasty system (Johnson & Johnson, New Brunswick, NJ, USA). In case of straightforward surgery according to the TruMatch cutting blocks, the authors achieved excellent radiological and anatomical intraoperative results but faced significant flexion gap instability. Therefore, before performing the tibial cut using the TruMatch system the authors recommend double-checking the axis with the conventional alignment tower. In addition, the authors apply the femoral TruMatch cutting block and test its position with respect to adequate flexion gap balance and rotation using the Ranawat block [5]. After adjustment with the tibial alignment tower and the Ranawat block, not only appropriate cutting to the anterior femoral cortex, as measured using the TruMatch system, but also a well-balanced flexion gap can be achieved. We believe that surgeons should always double check patient-individualised cutting blocks using their conventional guides and hope that this letter will assist other knee surgeons in doing so. When using patient individualised cutting blocks, surgeons should avoid a straightforward application of these tools without critical verification, which might on the other hand counter the claimed time reduction.


  1. 1.
    Nunley RM, Ellison BS, Ruh EL, Williams BM, Foreman K, Ford AD, Barrack RL (2012) Are patient-specific cutting blocks cost-effective for total knee arthroplasty? Clin Orthop Relat Res 470(3):889–894PubMedCrossRefGoogle Scholar
  2. 2.
    Nunley RM, Ellison BS, Zhu J, Ruh EL, Howell SM, Barrack RL (2012) Do patient-specific guides improve coronal alignment in total knee arthroplasty? Clin Orthop Relat Res 470(3):895–902PubMedCrossRefGoogle Scholar
  3. 3.
    Schnurr C, Eysel P, König DP (2011) Displays mounted on cutting blocks reduce the learning curve in navigated total knee arthroplasty. Comput Aided Surg 16(5):249–256. doi: 10.3109/10929088.2011.603750 PubMedCrossRefGoogle Scholar
  4. 4.
    Matziolis G, Matziolis D, Perka C (2012) Pre-operative frontal plane malalignment predicts the extension gap asymmetry in knee osteoarthritis. Int Orthop 36(1):79–82PubMedCrossRefGoogle Scholar
  5. 5.
    DePuy International Ltd (2007) Surgical technique. Accessed 15 July 2012

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Norbert Kastner
    • 1
  • Gerald Gruber
    • 1
  • Patrick Sadoghi
    • 1
    Email author
  1. 1.Department of Orthopaedic SurgeryMedical University of GrazGrazAustria

Personalised recommendations