Knee

Through small incisions, usually half a centimeter to one centimeter long, we insert a camera and fine instruments into the knee. This lets us see cartilage, menisci and cruciate ligaments directly and treat them in the same procedure. The surrounding tissue is barely strained.

Typical reasons

• Meniscus tear: smoothing or suturing, so that the knee's shock absorber is preserved as far as possible
• Cartilage damage: smoothing, microfracture or cartilage cell transplantation, depending on the extent
• Cruciate ligament tear: replacement with one of your own tendons

Procedure

• Before: examination, X-ray and MRI, then we decide together
• Surgery: usually 30 to 90 minutes, under general or regional anesthesia, as a rule as an outpatient at the IsarAOP Zentrum
• Afterwards: cooling, elevating, early movement and physiotherapy according to plan

Arthroscopy makes sense when physiotherapy, injections or medication are not enough or when there is mechanical damage. It often helps preserve your own joint for longer.

The anterior cruciate ligament keeps the thigh and lower leg stable in relation to each other. If it tears, the knee often gives way, especially when stopping abruptly or walking downhill. People who do not play sports with quick changes of direction sometimes manage well with targeted muscle training. For athletes and in case of accompanying injuries, ACL reconstruction is usually the more sustainable solution.

Reconstruction makes sense if

• the knee repeatedly gives way
• you want to play sports with quick changes of direction
• the meniscus or cartilage is also injured
• you want to return to sports or work quickly

Three techniques, always with your own tendon

• Hamstring tendon from the back of the thigh: the proven standard
• Patellar tendon with small bone blocks (BTB): very stable, often used in competitive sports
• Quadriceps tendon: a proven alternative, for example when a previous graft has torn again

Timeline

Cycling is usually possible after six to eight weeks, light running after three to four months, competitive sports usually after six to nine months. Before you return to sports, we test strength and stability.

A joint replacement only becomes an option once joint-preserving approaches have been exhausted. A partial knee replacement replaces only the worn side of the joint. The cruciate ligaments and healthy cartilage are preserved, and the knee feels more natural. A total knee replacement replaces all joint surfaces and provides stability when osteoarthritis affects the entire knee.

A partial replacement is more likely if

• wear and pain are limited to the inner or outer side
• the ligaments, especially the anterior cruciate ligament, are stable
• the leg axis is largely straight
• the knee can still be moved well

A total replacement is more likely if

• several parts of the joint are affected
• the knee is unstable
• there are pronounced knock knees or bow legs
• the menisci are also severely damaged

The X-ray and the examination are decisive. Dr. Willers operates at Klinik Josephinum with an inpatient stay. Movement therapy starts on the first day after surgery, followed by rehabilitation over several weeks, either outpatient or inpatient.

Dr. Willers in an interview: When the knee gives out (Klinik Josephinum, July 18, 2026, PDF in German)

Dr. Willers in an interview on knee replacement (Klinik Josephinum, May 10, 2025, PDF in German)

Whether arthroscopy, ACL reconstruction or joint replacement: aftercare plays a key role in the result. You receive a clear plan and fixed follow-up appointments from us.

• The first two weeks: relieving pain and swelling, cooling, elevating, first exercises with physiotherapy
• After that: gradually building up strength, mobility and coordination, usually faster after arthroscopy and ACL reconstruction than after a joint replacement
• Finally: training for everyday life and sports, for athletes with tests before returning to play

With a joint replacement, we check the position and healing on an X-ray after a few months. What also helps: a balanced diet, enough sleep and a regular daily routine.

Every operation carries risks. We discuss them openly with you beforehand. Most complications can be treated well if they are detected early.

General

• Infection
• Thrombosis and embolism
• Bleeding and swelling
• Anesthesia risks, which you discuss with the anesthesiologist beforehand

Depending on the procedure

• Arthroscopy: joint effusion or temporarily restricted mobility
• ACL reconstruction: adhesions or decreasing tension of the new ligament
• Joint replacement: loosening or wear, usually only after many years

Please contact us immediately if you have

• increasing pain despite painkillers
• severe swelling, redness or warmth
• a fever or feel very unwell
• pain or swelling in the calf
• If you suddenly become short of breath, call 112 immediately