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CC BY-NC-ND 4.0 · Z Orthop Unfall 2022; 160(02): 149-159
DOI: 10.1055/a-1304-3854
Review

Arthroplasty of the Knee: Current Techniques for Implant Alignment

Article in several languages: English | deutsch
Patrick Weber 
1   ECOM Group practice for orthopedic surgery, sports medicine and traumatology, Munich, Germany
2   ATOS Clinic, Munich, Germany
3   Dep. of Orthopedic Surgery, Physical Medicine and Rehabiliation, University Hospital (LMU), Munich, Germany
,
Hans Gollwitzer
1   ECOM Group practice for orthopedic surgery, sports medicine and traumatology, Munich, Germany
2   ATOS Clinic, Munich, Germany
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Abstract

When a total knee arthroplasty (TKA) is implanted using the traditional mechanical alignment technique, this typically results in a straight leg, independently of pre-operative or even pre-arthrotic varus or valgus alignment. With mechanical alignment, we distinguish between 2 different alignment techniques: ligament balancing and bony referencing according to bony skeletal landmarks. In ligament balanced technique beside the straight mechanical axis, the prosthesis is implanted at 90° to the latter. The rotational alignment of the femur is set according to the ligament tension. In the skeletal referenced technique, the rotation of the femur is also set according to bony skeletal landmarks. As a variation of this technique, the prosthesis can be implanted with anatomical alignment. In this technique, the medial slope of the joint line of 3° in the frontal plane is respected during the implantation of TKA. Both techniques result in comparable long-term results with survival rates of almost 80% after 25 years. On the other hand, 15 – 20% of TKA patients report dissatisfaction with their clinical result. For more than 10 years now, the kinematic TKA alignment concept has been developed with the goal to achieve implantation that is adapted to the individual anatomy of the patient. The advocates of this technique expect better function of TKA. This strategy aims to reconstruct the pre-arthrotic anatomy of a given patient while preserving the existing joint line and the mechanical axis without performing ligamentary release. Studies have shown that the function of the prothesis is at least that good as in the conventional techniques. Long-term results are still sparse, but initial studies show that TKA implanted using the kinematic alignment technique exhibit comparable 10-year-survival rates to those implanted using the traditional mechanical alignment technique. Future studies need to show the limitations of this new technique and to identify patients who will or will not significantly benefit from this technique.

Key words

knee arthroplasty - mechanical alignment - gap balancing - measured resection - kinematic alignment


Publication History

Article published online:
01 March 2021

© 2022. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).

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