22 Mar Interview with Dr. Christian Wedemeyer
Return of cementless knee arthroplasty?
Cemented anchoring of knee endoprostheses is currently considered the standard. For some time now, cementless fitting has been getting a new boost, among other things due to state-of-the-art knee systems such as the 4-motion® knee system, which is committed to anatomical reconstruction. Prof. Dr. Christian Wedemeyer, head physician for orthopaedics and trauma surgery at the St. Barbara Hospital in Gladbeck, has been consistently implanting cement-free implants with his team for years and reports on his experiences in this interview.
ARTIQO: What speaks in favour of cementless anchoring of knee endoprostheses?
Wedemeyer: On the one hand, it is the very good experience we have had with it in Gladbeck for about 25 years. My predecessor and former boss already implanted cementless implants. I have been doing this since 2007 and have also been able to prove scientifically that cementless implant variants work well and offer a stable fixation in the bone.[1] On the other hand, the operating time is reduced because we do not cement and we see very good osteointegration. There is no extra layer of cement that can age and break down. Once the implant is fixed, it stays fixed. Even with acrylic wear, we don’t see implant loosening. And finally, we appreciate that a cementless restoration can be revised more easily, for whatever reason. This is especially relevant for younger patients.
ARTIQO: How do you select patients for cementless knee arthroplasty?
Wedemeyer: Very old people with pronounced osteoporosis should be treated with a cemented implant, otherwise there is a risk of the implant sintering in. As a rule, we get a picture of the bone quality intraoperatively and change over in case of doubt. This requires systems such as the EFK or the 4-motion® knee system, which offer both a cementless and a cemented implant option.
ARTIQO: In the professional discussion, an increasing interest in cementless anchorage in knee endoprosthetics is noticeable. How do you explain this trend?
Wedemeyer: In my opinion, this has to do with the expansion of indications in knee arthroplasty, as we are seeing more and more younger patients who are highly mobile and active and want to remain so. This is made possible by the medical-technological advancement of knee arthroplasty: the anatomical and kinematic alignment is an important keyword in this context, but also the state-of-the-art surface coatings that are available to us today.
ARTIQO: What indications do the registry data provide for cementless knee arthroplasty?
Wedemeyer: The EPRD Annual Report 2021 shows that cementless knee arthroplasty currently accounts for only a very small percentage in Germany. Only very few cementless knee systems are even listed in the German register. I see a similar process as we have witnessed in hip arthroplasty over the last 30 years: The change in clinical application takes time.
ARTIQO: What recent literature do you see as exemplary for a newly awakened interest in cementless knee arthroplasty?
Wedemeyer: There are justified reasons for an international trend towards cementless knee arthroplasty. Rodriguez published an article in 2021 entitled “The future is cementless knee arthroplasty”[2]. He presented excellent mid-term results in 802 patients. Chen showed last year in the Journal of Orthopaedic Surgery Research comparable long-term results of cemented and uncemented fixation in terms of service life, clinical scores and mobility.[3] Even in the elderly patient over 75 years of age, cementless knee arthroplasty has its justified place. For example, Goh published in the Journal of Arthroplasty a comparable outcome and service life of cementless knee arthroplasty in this age group compared to the cemented technique.[4] The general concerns about the risk of cementless fixation in these patients could not be substantiated. In another study by Goh in the Journal of Arthroplasty, no differences were shown regarding both fixation techniques even in obese patients with a BMI above 35.[5] In a recent review article by Uivaraseanu, biological integration in particular was mentioned as a potential advantage.[6]
ARTIQO: What is your practical experience with the 4-motion® knee system?
Wedemeyer: Our experience is very good. For me, the 4-motion® knee system is a further development of the EFK knee system, with which we have a lot of experience. Preoperative planning is essential for anatomical reconstruction. With a cementless restoration, I also have to resect very precisely because I cannot compensate with cement. The individually planned cutting blocks fit very well, are a precise guide for the saw, so that exact saw cuts are possible. If you compare the phantoms we receive from the ARTIQO company with the resected parts after the operation, you can see how precise the planning is. The knee joints that we have been fitting with the system since the beginning of the year all have a good range of motion without flexion and extension deficits. We are participating in the multicentre post-market clinical follow-up of the 4-motion® knee system and are looking forward to the results of the cementless version.
ARTIQO: Professor Wedemeyer, thank you very much for the interesting interview and your detailed comments.
[1] Wedemeyer C et al. Arch Orthop Trauma Surg. 2012 Dec;132(12):1759-64. DOI: 10.1007/s00402-012-1608-2. Epub 2012 Aug 30.
[2] Rodriguez, S., Ranawat, A.S. JOIO 55, 1096–1100 (2021). https://doi.org/10.1007/s43465-021-00508-0
[3] Chen, C., Shi, Y., Wu, Z. et al. J Orthop Surg Res 16, 590 (2021). https://doi.org/10.1186/s13018-021-02762-2
[4] Goh GS et al. J Arthroplasty, 2022 Mar;37(3):476-481.e1. Doi: 10.1016/j.arth.2021.11.031. Epub 2021 Nov 26.
[5] Goh GS et al. J Arthroplasty, 2022 Apr;37(4):688-693.e1. DOI: 10.1016/j.arth.2021.12.038. Epub 2022 Jan 3.
[6] Uivaraseanu, B et al. Exp Ther Med. 2022 Jan;23(1):58. DOI: 10.3892/etm.2021.10980. Epub 2021 Nov 18.