Knee Experts in Bern: articon Specialist Practice for Hip and Knee Surgery

articon - Specialist Practice for Joint Surgery
Dr Bernhard Christen, M.H.A. | PD Dr Tilman Calliess
Specialist in Knee Surgery
Bern, Switzerland

articon - Specialist Practice for Joint Surgery - Logo

Treatment Focus

  • Osteoarthritis surgery
  • Knee prostheses (computer-assisted, robotic-arm-assisted)
  • Replacement of knee prostheses
  • Hip prostheses (computer-assisted, minimally invasive, robotic-arm-assisted)
  • Replacement of hip prostheses
  • "Optimal recovery programme" for the knee and hip

Medical Range

Range of Diagnostic Services (Salem-Hospital)

  • State of the art digital radiography with all special images
  • MRI
  • CT
  • Ultrasound
  • EOS for whole-leg or full-body images


Range of Therapeutic Services

Range of Treatments for the Knee

  • Prosthetics
  • Medial hemi-knee prosthesis (inside)
  • Lateral hemi-knee prosthesis (outside)
  • Femoropatellar articular surface replacement (replacement of the trochlear groove and the back surface of the kneecap)
  • Combinations of partial prostheses
  • Total knee prostheses
  • Revisions of knee prostheses, replacements of knee prostheses
  • Partial and total robotic-arm-assisted knee prostheses (MAKO technology)
  • Computer-assisted knee prostheses
  • "Optimal recovery programme" for the knee
  • Joint-preserving knee operations
  • Arthroscopic cartilage debridement
  • Arthroscopic meniscal suturing and meniscal partial resections
  • Cruciate ligament replacement
  • Axial corrections and re-alignment operations
  • Cartilage therapy, cartilage replacement for the knees and kneecap
  • Recentering operations for the kneecap in the case of dislocation/instability (trochleaplasty, soft tissue procedures, MPFL augmentation)

Range of Treatments for the Hip

  • Total hip prostheses
  • Revisions of hip prostheses, replacement of hip prostheses
  • Computer-assisted total hip prostheses
  • Robotic-arm-assisted total hip prostheses (MAKO technology)
  • Minimally invasive total hip prostheses
  • "Optimal recovery programme" for the hip


About About articon – Specialist Practice for Joint Surgery in Bern

The articon special practice for joint surgery in Bern specializes in the treatment of degenerative diseases (osteoarthritis) of knee and hip joints (field of specialisation: prosthetic joint replacement). The focus lies on the diagnosis and treatment of pain and loss of function in the knee or hip joints as a result of wear and tear, injuries or operations.

Core Competence in Arthrosis Surgery of Hip and Knee Joints

Osteoarthritis refers to the wear and tear of the joints and is caused by permanent misstraining or injury. The ultimate goal of osteoarthritis surgery, along with all therapeutic options, is to minimise pain and regain fullest function as possible of the operated joint. Thus in return, improved quality of life and preservation of self-reliance and independence is a result - in accordance with articon’s motto: "Mobility is our Recipe".

Treatment Spectrum of Dr Christen and Dr Calliess

The therapy spectrum of Dr Christen and Private Lecturer Dr Calliess ranges from minimally invasive surgical procedures of the knee, such as arthroscopy to joint-preserving corrective osteotomies. The scope continues with partial or complete prostheses as well as revision surgery following joint prostheses.

The treatment spectrum for the hip is limited to prosthetics and revision prosthetics.

Knee Joint Arthroscopy

In orthopaedics, arthroscopy is used to complete diagnostics and is - at the same time - a minimally invasive surgical method as well. Arthroscopy of the knee involves inserting a camera and surgical instruments into the joint via two small portals in order to perform the procedure. Arthroscopy has a wide field of applications. In orthopaedics, for example, arthroscopy is used in case of wear-induced cartilage damage involving mechanical blockades or exposed joint bone or cartilage pieces. Further applications include partial removal or suture of meniscal damage as well as treatment of cruciate ligament ruptures. 

Conversion Osteotomy – Surgical Correction of the Leg Axis

In case of leg malposition, parts of the knee joint become overloaded. This leads to an uneven wear of the cartilage tissue and a wearing away damage occurs as a result. In this situation, a so-called conversion osteotomy can be applied to repair the axis of the knee joint. Knee specialists recommend this type of intervention especially for malpositions such as bow legs or knock knees in younger, active patients with little cartilage damage. When fixing the leg axis, parts of the bone tissue is severed. The axial correction can then be performed, and the bone is fixed with a plate in the desired new position. This correction permanently relieves the affected joint segments, helping delay or even prevent osteoarthritis. In case of complex malpositions, the articon practice uses modern computer-assisted surgical procedures using three-dimensional planning. In addition, patient-specific cutting blocks for exact three-dimensional axial correction and plate placement are utilized. If signs of wear are too advanced, treatment with a joint prosthesis should be considered.

Prosthetics – Implantation of Artificial Joints

Since the main focus of the articon specialist practice for joint surgery is placed on treatment of degenerative diseases such as osteoarthritis, the experts in orthopaedics and traumatology in Bern are engaged in using joint prostheses every day, provided that no other alternative exists. They have extensive expertise in the field of orthopaedics and, due to their many years of experience with joint prostheses, are well recognised as specialists in prosthetics of hip or knee joints.

Dr Christen has been successfully performing prosthetic joint replacements for years. After many years of training at various clinics, he has continued to refine and perfect surgical techniques as well as preparation and follow-up treatments of incisions. He is always at the cutting edge of technology. For over 10 years, state-of-the-art surgical techniques and computer navigation have been standard procedures. Since mid-2018, robotic-arm-assisted prostheses have been used. As a national and international knee professional, Dr Christen possesses a wide network. He chairs the Swiss Knee Expert Group and is a founding member of the European Knee Society.

Private Lecturer Dr Calliess has furthermore specialised in prosthetics for many years, in particular the knee joint. As an orthopaedic expert, he has already performed over 1000 prosthetic surgeries. In 2013, he was certified as "main surgeon" for prosthetics, a seal of quality for prosthesis specialists in Germany. His special focus is the idea of an improved, individualized prosthesis fitting. As one of the first surgeons in Europe, Dr Calliess has been working with robotic assistance systems in knee prosthetics since 2016. These systems are particularly interesting when it comes to the customisation of prosthetics, as they provide the surgeon with a great deal of additional information. These structures also provide a high degree of precision during surgical procedures.

The primary goal of the knee specialists in Bern is always to help their patients regaining mobility – because the patient's quality of life depends on it to a large extent. In line with this maxim, they distinguish themselves through particular expertise in the field of partial prosthetics. In about 50% of cases, articon uses partial prostheses or combined partial prostheses. A total prosthesis is only selected for advanced arthrosis. Another focus is placed on revision surgery following knee prosthesis. This refers to follow-up operations becoming necessary in case of complications with the prosthesis such as pain, infection, loosening or abrasion.

Dr Christen and Dr Calliess also adjust hip joints. In this field, they offer total hip prostheses as well as revision procedures following a hip prosthesis implant. For many years, hip prostheses have been inserted by means of computer navigation via minimally invasive access points, and recently also by means of robotic arm assistance.

Implantation of Knee and Hip Prostheses Using Computer Navigation and Robotic Assistance Systems

Total knee prostheses and hip prostheses are implanted with the support of computer navigation, which improves the positioning of the prosthesis components. Axis deviations or leg length differences are just as rare as the dislocation of a hip prosthesis after an operation, for example.

Since 2018, articon, in collaboration with the Permanence Clinic, has been the first location in Switzerland to offer robot-arm assisted operations for partial and total prostheses of the knee joint at the Salem Hospital to further improve patient safety and minimize surgical complications. The use of a surgical robot makes it possible to adapt the procedure and the prosthesis position even better in each individual case. After over a year of positive experiences with the MAKO technology for knee prostheses, the articon team inserts hip replacements with robotic-arm assistance as of summer 2019. Read an interview with Dr Calliess on robot-assisted hip and knee surgery.

Process Optimisation

Treatments are optimised by coordinating the processes of care, physiotherapy and anaesthesia from the first patient contact on through follow-up care (optimal recovery). For example, medication minimises blood loss and post-operative pain. Moreover, drains are no longer placed, and, if possible, bandages are not changed until the sutures are removed.

The patient is usually permitted plus encouraged to freely move and fully stress his joints immediately after surgery according to symptoms and complaints. This shortens the healing process and enables rapid recovery including the ability to walk again. These measures are particularly advantageous for elderly people who do not have to use walking sticks for a long time frame considering poles are mainly used for safety but not for relief.

Latest Joint Prostheses and Surgical Techniques for Sound Durability

Flawless joint replacement is an essential factor for the long-term survival of artificial joints and patient satisfaction. This is why articon uses state-of-the-art plus well-proven prosthesis models. Dr Christen and Private Lecturer Dr Calliess are actively involved in the co-development (nationally and internationally) of prostheses and surgical techniques for knee prostheses. They both participate in national and international professional societies.

Revision Interventions for Joint Prostheses

In rare cases, a repeat operation is required after insertion of an artificial joint. Occasionally, the introduction of a prosthesis evokes pain, functional deficits appear, or the prosthesis loosens or causes inflammation. Or else, the joint prosthesis has been doing its job for many years and is showing signs of wear – in this cases, it is also necessary to replace the prosthesis. 

Due to their high degree of specialisation in joint prosthetics, Dr Christen and Dr Calliess have also acquired great expertise in replacement knee prosthetics over many years. Therefore, they serve as a reference centre for a large transregional, nationwide sphere of influence. The special competence lies in the detailed problem solving analysis of painful knee prostheses. This ability is topped by the availability of modern diagnostics at the Salem-Hospital site. It allows individual treatment concepts to be designed specifically to address and solvie the problem. articon offers all possible concepts and implants for revision prosthetics of the knee joint.

Advanced Training of Assistant and Senior Physicians

Dr Christen’s and Dr Callies' experience and knowledge also allows them to be qualified trainers for young assistant or senior physicians in the field of orthopaedics. At their practice, they try to convey not only their knowledge but also their passion for this area of medicine. Dr Christen has been cooperating with the University Orthopaedic Department at Bern Hospital since the mid-2013 and maintains a rotation position for junior doctors engaged in advanced training programs to become specialists in orthopaedics and traumatology of the musculoskeletal system. Private Lecturer Dr Callies is involved in training and teaching at the Hannover Medical School, where he holds a lectureship.

Articon’s Philosophy: a Trusting Doctor-Patient Relationship

Mutual trust between doctor and patient is a high priority for Dr Christen and Dr Calliess. As a patient, you should express your wishes, fears and questions regarding upcoming treatments. This is the only way for the joint specialists and their team to find the individually optimal therapy for your complaints and to suggest a therapy that satisfies you and has a maximum chance of success. For this purpose, the articon practice team applies its empathy, utmost care, medical knowledge and skills, supported by state-of-the-art medical technology.

The most important focus for the two physicians is a high level of professional competence through specialization. According to their opinion, this is the only way to keep pace with the developments in modern medicine, which is becoming more and more complex - at the highest international level - and to offer patients optimal medical care.

Through the alliance of two recognised experts in the field of knee and hip surgery, Dr Christen and Private Lecturer Dr Calliess always keep getting better. A close professional exchange of expertise and a permanent, self-critical evaluation of their therapies are of paramount importance to them. They always try to organise and continually optimise all building blocks of a treatment according to the latest scientific findings. In addition, the articon practice stands for a high degree of mechanisation of surgical procedures in order to guarantee highest quality in a comprehensible manner. For years, they have been among the top leading minds in computer-assisted orthopaedic surgery in Europe and are actively shaping the future in this area.

For Dr Christen and Dr Calliess, good preliminary work (diagnosis) is at least as important as the actual execution of the surgery. That's why the orthopaedists take a lot of time for a personal conversation at the beginning of the meeting with a patient. They inquire about her or his complaints, ideas and expectations, perform an examination and evaluate the imaging results (X-rays, MRI, CT, etc.). Based on the diagnosis, the two physicians inform each patient in detail about treatment options including benefits and risks of the various therapeutic options. Consequently, patients can decide on their personal best solution. The high quality standards for their work apply to the entire practice team.

 The articon team wants to convey mobility and remain mobile itself - as a credo of its work. For supporting information, you will find details about diagnosis and treatment alternatives on their homepage.

The articon specialist practice for joint surgery can be found inside the Salem Hospital in Bern (floor E3 in the Elim building). All operations are performed by Dr Christen and Private Lecturer Dr Calliess at the Salem Hospital in Bern. This is a modern-equipped clinic offering a high degree of comfort for its patients. For international patients, a dedicated guest care advisor is available to ensure that needs are met and that the stay is facilitated.

Since mid-2015, Dr B. Christen has also been active as a founding member and partner at the SportsClinic#1, which includes a second practice location at ‘Stade de Suisse’ in Wankdorf, Bern. At this institution, established specialists from private practices and the University Orthopaedic Department of Bern Hospital all work together.

Curriculum Vitae

Dr Bernhard Christen, MHA

1977-1982 Degree in medicine at the University of Bern
1983-1992 Assistant Physician, Internal Medicine, General Surgery, Orthopaedics at the Buergerspital, Solothurn and at the Inselspital Bern
1987 Dissertation
1992 Specialist examination in Orthopaedics and Traumatology
1992-1997 Consultant in Orthopaedics, Buergespital, Solothurn
1996 Fellowship in Shoulder Surgery, Balgrist University Hospital, Zurich
1997-2002 Head physician of Orthopaedics and Traumatology, Surgical Clinic, University Hospital Bern Ziegler with 5 years of additional training in the field of knee and hip prosthetics
2002 Master of Health Administration (MHA)
2012 Attending doctor with office at the Salemspital Bern
Since 2015 Foundation of Christenortho AG
Since 2015 Founding member and partner at the Sports Clinic#1, Bern
2018 Foundation of the articon specialist practice for joint surgery

PD Dr Tilman Calliess

1998–1999 Paramedic at the German Red Cross
1999 – 2006 Medical studies at Hannover Medical School
2005 Semester abroad in Perth/Brisbane, Australia
2006–2012 Assistant Physician for Orthopaedics and Traumatology at the Orthopaedic Clinic of Hannover Medical School in Annastift
2008 Dissertation
2011 Fellowship for tumour surgery, Medical University Hospital of Vienna
2012 Specialist in orthopaedics and traumatology
2012–2018 Senior Physician in Charge of a Unit at the Department of Endoprosthetics and Reconstructive Joint Surgery at the Orthopaedic Clinic of the Hannover Medical School in Annastift
2012–2018 Head of the Tumour Orthopaedics Unit at the Orthopaedic Clinic of the Hannover Medical School in Annastift
2013 Certified Main Surgeon for Endoprosthetics at the Endocert Endoprosthetics Centre of Maximum Care
2017 Additional training in special orthopaedic surgery and specialised skeletal X-ray diagnostics
2017–2018 Habilitation
Senior Physician/Team Leader for Knee Endoprosthetics at the Orthopaedic Clinic of Hannover Medical School in Annastift

Medical Team

  • Dr Bernhard Christen, M.H.A.
    Specialist Physician in orthopaedic surgery and traumatology of the locomotor system
  • PD Dr Tilman Calliess
    Specialist Physician in orthopaedic surgery and traumatology of the locomotor system, specialist in special orthopaedic surgery, Specialist Physician in skeletal X-ray diagnostics


  • Alpine panorama and view of the old town of Bern
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  • Hirslanden Privé for private patients: personal Guest Relations Advisor and attractive additional services, free overnight stay for relatives in the guest bed
  • Single and two-bed rooms with bath or shower cubicle
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  • 24-hr Emergency Centre


Bern central railway station 5 km
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Basel airport 106 km
Zurich airport 129 km
Geneva airport 152 km

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articon - Specialist Practice for Joint Surgery
Dr Bernhard Christen, M.H.A. | PD Dr Tilman Calliess

Schänzlistrasse 39, CH-3013 Bern

T: +41 31 511 83 18
F: +41 31 337 89 54


Tuesday and Thursday 8:00 a.m. - 6:00 p.m.

Sports Clinic#1AG
Papiermühlestrasse 73, CH-3014 Bern

T: +41 31 356 11 22
F: +41 31 356 11 23


Tuesday 9:00 a.m. - 5:00 p.m.

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