In addition to evidence-based medicine at the current state of research, the patient is our focus. Our research specializes in the collection and evaluation of patient data after surgery. The patient’s perspective plays a central role in this. Certain information can only be provided by the patient and is important to us in verifying the quality of the treatment.
Our research projects are carried out in accordance with international guidelines and Swiss legislation and are partly carried out in cooperation with other clinics. You can find a selection of our current research projects here.

How are our Patients after a Knee Replacement?

Since 2016 the knee team of the LEONARDO practice has been conducting a survey at several stages with all patients who have received a knee joint prosthesis. The results are impressive: One year after the surgery, 91% of the patients questioned were “very satisfied” or “satisfied” with their knee joint prosthesis. Two years after the surgery, 88% of the patients are “very satisfied” or “satisfied”. Almost all patients (96%) would have the surgery performed again under the same circumstances. In addition, 88% of patients after one year and 89% after two years state that the condition of their knee joint is “very much better” or “significantly better” than before the operation.

Our patients’ functional ability also improved significantly in the first two years with the “new” knee joint. The following diagram provides an overview:

The scale is from 0 to 100 points with higher values indicating better function.

The figure tells you, that knee function measured in different subscales clearly improved four months after the surgery and still increases over the next months. Likewise, the overall health state that not only refers to the knee could be improved. The term “forgotten knee joint” means, that you are not aware of your artificial knee joint in everyday life. It indicates how normal your knee joint feels.

To collect so called „patient-reported outcome measures“ (PROMs) means some extra effort for us, especially as we are interested in long term results. This project is all the more important because it reflects the patient’s perspective and gives us valuable information about the success of therapy. The participation is of course voluntary. Approximately 80% of our patients agreed to complete six questionnaires in five years. The high number of participating patients gives even more importance to our very good results.

SKOOP Stable Knee withOut OPeration

A torn anterior cruciate ligament (ACL) can heal stably without surgery under certain circumstances. In this project, we are investigating the effectiveness of our treatment concept “SKOOP”. Treatment consists of conservative splint therapy and physiotherapy instead of surgery. Participating patients receive questionnaires at regular intervals by email and come for an MRI examination after 12 months. This is how we control the stable healing of the ACL. If it becomes apparent, during the course of treatment, that the ACL has not healed stably and that there is insufficient stability, surgical reconstruction of the ACL may be necessary.
We ask all appropriately qualifying patients in our practice, if they would like to participate in this project. Participation is of course voluntary. More information can be found here in the Participant information sheet (only German version available).

German Cartilage Registry

The Cartilage Register of the German Society for Orthopedics and Trauma Surgery is a web-based database which, using questionnaires, records data of patients (from Switzerland, Austria and Germany) with any cartilage damage.
Since 2013, anonymous data on cartilage surgery has been stored here and evaluated later. The goal is a scientific evaluation of the effectiveness and safety of such interventions. We have been certified as a recruitment center for the German Cartilage Registry since 2016 and ask all patients who we will treat, because of cartilage damage to the knee or ankle, if they want to participate in the registry. Participation is of course voluntary and does not affect the therapy. After you have given your consent, you will receive the questionnaires by email at regular intervals.
Further information: Link to Flyer and Homepage

Poster Presentations

1 – «Clinical and Patient Reported Outcomes after Customized Individually Made Total Knee Arthroplasty» Annual Congress Swissorthopaedics, June 2021

2 – «Clinical and Patient-Reported Short-Term Results after Customized Individually Made Total Knee Arthroplasty» Annual Congress Swissorthopaedics, September 2019

3 – «Aseptic tibial loosening in cemented primary total knee replacement with tibial tubercle osteotomy – is it due to the screw?» 7. Annual Congress of the German Knee Society, November 2018

4 – «Persistent medial joint pain after high tibial osteotomy – did you sufficiently release the medial collateral ligament?» 35. AGA Congress, September 2018



Vogel N, Kaelin R, Rychen T, Wendelspiess S, Müller-Gerbl M, Arnold MP. High Expectations Among Patients Who Have Undergone TKA Do Not Correlate With Satisfaction. Clin Orthop Relat Res. 2024 Feb 28. doi: 10.1097/CORR.0000000000003010. Epub ahead of print. PMID: 38416118. Link

Vogel N, Kaelin R, Rychen T, Wendelspiess S, Müller-Gerbl M, Arnold MP. Comparison of Responsiveness of Patient-Reported Outcome Measures After Total Knee Arthroplasty. J Arthroplasty. 2023 Dec 1:S0883-5403(23)01172-5. doi: 10.1016/j.arth.2023.11.029. Epub ahead of print. PMID: 38043745. Link

Vogel N, Kaelin R, Rychen T, Wendelspiess S, Müller-Gerbl M, Arnold MP. Satisfaction after total knee arthroplasty: a prospective matched-pair analysis of patients with customised individually made and off-the-shelf implants. Knee Surg Sports Traumatol Arthrosc. 2023 Dec;31(12):5873-5884. doi: 10.1007/s00167-023-07643-1. Epub 2023 Nov 20. PMID: 37982843; PMCID: PMC10719143. Pdf


Wendelspiess S, Kaelin R, Vogel N, Rychen T, Arnold MP. No difference in patient-reported satisfaction after 12 months between customised individually made and off-the-shelf total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2022 Feb 12. doi: 10.1007/s00167-022-06900-z. Epub ahead of print. PMID: 35149877. Pdf


Vogel N, Kaelin R, Rychen T, Arnold MP. The German version of the High-Activity Arthroplasty Score is valid and reliable for patients after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2021 Mar 26. doi: 10.1007/s00167-021-06531-w. Epub ahead of print. PMID: 33770220. Link

Kaelin R, Rychen T, Vogel N, Mathis D, Arnold MP (2021) Restschmerz nach medial öffnender Tibiakopfosteotomie. Arthroskopie.

Arnold MP, Calcei JG, Vogel N, Magnussen RA, Clatworthy M, Spalding T, Campbell JD, Bergfeld JA, Sherman SL; ACL Study Group. ACL Study Group survey reveals the evolution of anterior cruciate ligament reconstruction graft choice over the past three decades. Knee Surg Sports Traumatol Arthrosc. 2021 Jan 24. doi: 10.1007/s00167-021-06443-9. Epub ahead of print. PMID: 33486558. Link

Forster-Horváth C, Unterreithmeier U, Fries S, Ganal S, Gütler J, Vogel N, Herzog RF. Midterm Follow-Up and Assessment of Cartilage Thickness by Arthro-Magnetic Resonance Imaging After Arthroscopic Cam Resection, Labral Repair, and Rim Trimming Without Labral Detachment. Arthroscopy. 2021 Feb;37(2):541-551. doi: 10.1016/j.arthro.2020.10.012. Epub 2021 Jan 2. PMID: 33359757. Link


Vogel N, Rychen T, Kaelin R, Arnold MP (2020) Patient-reported outcome measures (PROMs) following knee arthroplasty: a prospective cohort study protocol. BMJ Open 10:e040811 Pdf

Acevedo L, Iselin L, Berkelaar MHM, Salzmann GM, Wolf F, Feliciano S, Vogel N, Pagenstert G, Martin I, Pelttari K, Barbero A, Arnold MP. Comparison of Human Articular Cartilage Tissue and Chondrocytes Isolated from Peripheral versus Central Regions of Traumatic Lesions. Cartilage. 2020 Sep 22:1947603520958154. Link

Shamdasani S, Vogel N, Kaelin R, Kaim A, Arnold MP. Relevant changes of leg alignment after customised individually made bicompartmental knee arthroplasty due to overstuffing. Knee Surg Sports Traumatol Arthrosc. 2020 Sep 11. doi: 10.1007/s00167-020-06271-3. Epub ahead of print. Link


Haeni DL, Vogel N, Tamborrini G (2019) Ultraschalldiagnostik und Chirurgie der distalen Bizepssehne. Rheuma Schweiz


Niemeyer P, Becher C, Brucker PU, Buhs M, Fickert S, Gelse K, Günther D, Kaelin R, Kreuz P, Lützner J, Nehrer S, Madry H, Marlovits S, Mehl J, Ott H, Pietschmann M, Spahn G, Tischer T, Volz M, Walther M, Welsch G, Zellner J, Zinser W, Angele P (2018) [Significance of Matrix-augmented Bone Marrow Stimulation for Treatment of Cartilage Defects of the Knee: A Consensus Statement of the DGOU Working Group on Tissue Regeneration]. Z Orthopadie Unfallchirurgie 156:513–532 Link

Kaelin R, Christen B, Eggli S, Miozzari H, Arnold MP (2018) Behandlung degenerativer Meniskusläsionen. Swiss Med Forum EMH Media 18:147–153 Link

Mathis DT, Kaelin R, Rasch H, Arnold MP, Hirschmann MT (2018) Good clinical results but moderate osseointegration and defect filling of a cell-free multi-layered nano-composite scaffold for treatment of osteochondral lesions of the knee. Knee Surg Sports Traumatol Arthrosc 26:1273–1280 Link


Forster-Horvath C, Domb BG, Ashberg L, Herzog RF (2017) A Method for Capsular Management and Avoidance of Iatrogenic Instability: Minimally Invasive Capsulotomy in Hip Arthroscopy. Arthrosc Tech 6:e397–e400 Link


Arnold MP, Rychen T (2016) Knieprothetik nach Mass aus dem 3D-Drucker. Swiss Med Forum 16:702–6 Link

Forster-Horváth C, Artz N, Hassaballa MA, Robinson JR, Porteous AJ, Murray JR, Newman JH (2016) Survivorship and clinical outcome of the minimally invasive Uniglide medial fixed bearing, all-polyethylene tibia, unicompartmental knee arthroplasty at a mean follow-up of 7.3years. The Knee 23:981–986 Link

Forster-Horvath C, von Rotz N, Giordano BD, Domb BG (2016) Acetabular Labral Debridement/Segmental Resection Versus Reconstruction in the Comprehensive Treatment of Symptomatic Femoroacetabular Impingement: A Systematic Review. Arthrosc J Arthrosc Relat Surg 32:2401–2415 Link