Have any questions?
+44 1234 567 890
Anterior cruciate ligament surgery with a minimally invasive technique (arthroscopic)
The typical injury mechanism is excessive load on the knee joint in flexion or external rotation, and genu varum. In this case, rotational forces acting on the knee injure the medial collateral ligament, and sometimes also the inner or outer meniscus. This results in over-stretching or tearing of the anterior cruciate ligament.
The anterior cruciate ligament is an essential stabilizer. If the cruciate ligament is torn, the patient complains about a feeling of instability and about the knee joint "giving up", especially when exercising. Even very well trained muscles can only partially compensate for the instability. It is usually no longer possible to practise sports such as football, handball, tennis, basketball, or alpine skiing (= rotational sports). In the long run, instability and the associated disorder of the joint mechanics (increased friction, changed pivot point, changed pressure distribution) cause further damage to the inner or outer meniscus and the cartilage. This is how osteoarthritis begins. Therefore, unstable knee joints should be treated surgically early on, especially in athletic patients. The primary goal of the surgery is to make the joint "stable" in order to avoid consequential damage to the meniscus and articular cartilage. Since sole suture repair does not provide stability for biological reasons, reinforcement or replacement with the body's own tendon material is necessary.
Our knee surgery specialists in Freiburg use the semitendinosus tendon for cruciate ligament replacement, or alternatively the patellar or quadriceps tendon. These replacement tendons have proved their worth in cruciate ligament surgery over many years. Once inserted, the tensile strength and elasticity of these tendons is similar to that of the natural cruciate ligament. A large number of studies confirm the excellent results. The semitendinosus tendon is one of several flexor tendons of the knee. Removal of this tendon does not cause loss of strength or flexibility. Removing the tendon through a small skin incision on the inside of the knee leaves a barely visible scar. Compared to open procedures, fully arthroscopic ACL replacement surgery is much less tasking for the knee joint. There is significantly less knee pain after a cruciate ligament surgery, and rehabilitation can be started very early on. For a successful knee surgery, it is essential to precisely position bone canals in the tendon insertion sites of the original cruciate ligament. These boreholes can be made with precision under arthroscopic control with the help of precise aimers. The tendon is folded three or four times to make sure that it has sufficient tensile strength. First, the replacement tendon is inserted into the knee joint through the drill tunnel in the tibial plafond. It is then anchored in the bone canal of the femur using two absorbable pins (cross-pin anchoring). Alternative fixation using a small titanium plate according to the toggle bolt principle is another proven method. We use a small titanium knob to attach the tendon to the tibial plafond. This innovative fastening principle allows for very stable anchoring, and guarantees uneventful healing of the tendon. It is usually not necessary to remove the metal later on. Concomitant damage to the meniscus or the cartilage can be treated at the same time. In favourable cases, the meniscus can be sutured in order to preserve it. Cruciate ligament surgeries are performed on an outpatient basis, or during a short hospital stay.
Rehabilitation after cruciate ligament surgery essentially consists of movement exercises, an intensive muscle strengthening program, and coordination training, which start early on. Continuous motion with the help of a splint, and controlled exertion, have a very beneficial effect on nutrition of cartilage and graft healing. Muscle stimulation devices (TENS) can help reduce muscle atrophy in the thigh. A removable and adjustable splint (orthosis) should be worn for a few weeks to protect the graft.
A good working relationship between the patient, the physiotherapist, and the experienced surgeon is necessary to ensure good surgical results. Most patients will have their full weight bearing capacity restored in 3-5 weeks. Advanced outpatient rehabilitation begins from the 3rd week. Bicycle ergometers have proven to be of great value as training devices. After approx. 6-8 months, if the patient has trained his or her thigh muscles and regained their stability, they can start practising rotational sports, such as football, handball, basketball, and alpine skiing.
Cruciate ligament reconstructions usually have very good surgical outcomes. Most patients will be able to continue practising their sport at a high level.
Meniscus surgery using minimally invasive technique (arthroscopy)
During an arthroscopic meniscus surgery, the optical system and an examining hook are inserted into the knee joint via two tiny skin incisions. First, the entire joint is examined.
Meniscus surgery aims at preserving the intact meniscus tissue. In some cases (especially in young patients after accidents), it is possible to suture the tear and reattach the meniscus (by suturing or reattaching with special anchors, similar to staplers). In many cases, however, torn meniscus tissue is damaged too much and cannot be preserved. The damaged part of the meniscus is then carefully removed using micro-punches. It is crucial to preserve the healthy portion of the injured meniscus.
Rehabilitation / follow-up treatment / sports
Functional therapy starts soon after a meniscus surgery. Canes permit immediate partial weight bearing. To prevent blood clots (thromboses), so-called heparin injections should be administered once a day for approx. 7-10 days. Most patients achieve full weight bearing after just a few days, and are able to take up gentle sport activities after 2 weeks. Meniscus sutures require a significantly longer follow-up treatment. In these cases, the joint may bear only partial weight for the first few weeks. Mobility is initially restricted. It is then gradually increased allowing the meniscus that has been reattached or sutured to heal.
The prognosis after a meniscus surgery is very good. Most patients can continue practising their sports without any issues. In case of larger meniscus tears, special inserts or changes to shoe soles may provide compensation later on. If patients experience any problems after the surgery, we ask them to come back to our hospital. This will allow us to ensure optimal healing, and quickly address any complications.
Knee cartilage repair using minimally invasive technique (arthroscopy)
During an arthroscopic cartilage surgery, the optical system and an examining hook are inserted into the knee joint via two tiny skin incisions. The entire joint is examined first with the aim of preserving the healthy structure and repairing the damaged tissue.
If cartilage damage already extends to the bone, an attempt is made to stimulate the formation of resilient replacement cartilage. Small holes are drilled in the defect zones using a special instrument. This procedure releases the so-called stem cells, which go on to develop replacement cartilage. This technique can be used to treat even relatively large areas of damaged cartilage. (Microfracture technique)
In another technique, several round cartilage-bone cylinders are retrieved from areas of the joint that are less affected. They are then inserted into the defect zone in the cartilage. It is the body's own material, which has a very good healing potential. This technique is only suitable for some cartilage defects in younger patients. (Cartilage-bone graft)
The original cartilage lining cannot be restored completely. Good results can only be achieved if joint instabilities that cause cartilage damage are treated surgically at the same time. This also applies to existing axis misalignments (e.g. bow legs / valgus malalignment). These cases require an additional axis correction.
Following a cartilage surgery, walking aids must be used for 4-12 weeks. This prolonged strain relief is necessary to allow the replacement cartilage to form. Follow-up physiotherapy is required for a period of 3 months. The patient starts using the CPM splint to perform passive movements immediately after the knee joint surgery. Muscle strengthening training starts early on with the help of the stationary bike and water gymnastics.
Patella stabilization after an accident
If the kneecap is severely torn and unstable, a surgery is necessary to reconstruct the ligaments. This can be done through open suture of the joint capsule. In most cases, however, the torn joint capsule can be reattached to the kneecap using the minimally invasive keyhole technique (arthroscopy) and minimal incisions. Again, the prognosis is favourable.
Patella stabilization in spontaneous multiple dislocations (habitual luxation)
In this case, various unfavourable factors are corrected. A high-riding patella is corrected by moving its tendon base downwards to the normal position. The moved tendon base is securely attached with screws, which makes physiotherapy and partial weight bearing possible. Furthermore, the inner anterior thigh muscle (vastus medialis) is also moved downwards so that its direction of pull acts more on the inside of the knee. If the femoropatellar groove is heavily flattened and elongated pointing upwards, it is surgically cut to its approximate anatomical shape. In cases of severe instability, significant axis deviations, and rotational errors, it may be necessary to correct the axis (conversion osteotomies and rotation osteotomies). However, this is extremely rare.
The prognosis is favourable for most surgeries. The relapse rate is low. Surgical therapy requires a short inpatient stay of a few days. The surgery is followed by functional treatment with partial weight bearing for approx. four weeks. The physiotherapy takes approximately 3 - 4 months on the whole.
Axis correction (conversion osteotomy)
Surgical straightening of the leg axis is a joint-preserving intervention that reduces the load on the damaged joint, thereby preventing or at least slowing down the progression of osteoarthritis. The surgeon can see the extent of the knee joint malalignment on X-rays, and can thus calculate the required correction angle. Correct leg axis can be restored by removing a bone wedge from the outer tibial plafond. In the much rarer X-leg misalignments, the femur is corrected. Leg stability is preserved, since our surgical technique does not require severing the bone completely. This is why partial weight bearing with half the body weight is possible immediately thereafter. To keep the correction angle, the bones are stabilized using a metal plate. Additional minimally invasive knee joint surgery (arthroscopy) is required in order to carry out interventions on the cartilage or meniscus (e.g. meniscus smoothing). If joint instability is present (cruciate ligament damage), it can be treated alongside axis correction. This surgical method ensures good results. It requires a (short) inpatient stay of 1-3 days.
Rehabilitation starts on the first day following the surgery. The knee is also passively mobilised using a CPM splint. Partial weight bearing is possible immediately. A period of 3-4 months should be considered for the rehabilitation.
Knee joint replacement / artificial knee joint (prosthesis, total knee replacement)
Our specialist for knee replacement is Dr. Ralph Mayer. Dr. Mayer has a long-standing experience in the field of prosthetics.
Damaged joint surfaces are replaced with surface replacement prostheses, in the form of partial prostheses (unicondylar knee replacements) or total knee prostheses. These modern types of prostheses require removing only the diseased tissue and very little bone. Patient's own ligament structures (collateral and cruciate ligaments) remain intact. All types of prostheses consist of a component for the upper leg and the lower leg. The results have been significantly improved in recent years thanks to the development of prostheses that closely imitate natural movements of the normal knee joint (roll-slide movement). The size of the knee prosthesis is adjusted to each individual patient using a digital design sketch. It is implanted either without cement (press-fit technique), as a hybrid total endoprosthesis (the thigh section is cementless and the lower leg is cemented), or both components are implanted using bone cement. The gliding surfaces for the thigh section are made of titanium or chromium-cobalt alloys. The gliding section on the lower leg consists of polyethylene inserts, which allow a largely natural rolling and sliding and significantly reduce wear. On average, the durability of the new knee joint is 10-15 years.
The knee implants we use (LCS, DePuy Synthes and Oxford, Zimmer Biomet) have been on the market for decades and have been approved by the strict US Health Authority FDA. The same applies to our shoulder prostheses (Arthrex Univers), as well as the shoulder and knee implants from Arthrex based in Naples/Florida US which we use in endoscopy. Moreover, our prosthesis implants show excellent long-term results according to the Scandinavian and Australian registers databases.
Joint replacement surgeries must be performed in a hospital (inpatient stay of approx. 10-14 days). Rehabilitation starts immediately after the surgery. Patients are treated daily using physiotherapy and lymphatic drainage. CPM splints are available for passive motion exercises. After their stay in the acute care hospital, most patients are transferred to a rehabilitation hospital for another 3-4 weeks. The entire treatment will take 3-4 months. If the surgery goes well and the rehabilitation is successful, sports such as cycling, swimming, and playing golf can be practised again.
Unicondylar prosthesis (partial prosthesis, medial implant) - the "half" artificial knee joint
There are many ways of surgically treating isolated signs of wear from the inside of the knee. On the one hand, there is the possibility of relieving the strain on knee joint by straightening the leg. However, if the leg is not bowed, is bowed only slightly, or the wear / osteoarthritis of the inside has already progressed too far, it is possible to replace only the surface of the affected area. Implantation of such an unicondylar prosthesis is minimally invasive. Nowadays, a medial endoprosthesis that is inserted correctly works for 15-20 years without any problems. The prerequisites are: advanced osteoarthritis of the inside; X-shaped legs or bow legs that are not too pronounced; stable ligaments; extension reduced up to 10°; age from approx. 60 years. Osteoarthritis behind the kneecap is not an exclusion criterion.
The surgery may be performed under general anaesthesia or "spinal anaesthesia". It takes usually between 40 and 70 minutes. The access is provided along the inside of the patellar tendon. The cut is approx. 6-8 cm long. The defective articular surfaces on the tibia and femur are removed along with a little bone. The final prosthesis is cemented. This is followed by wound closure and drainage to avoid haematomas. The entire surgery is performed using a tourniquet (pressure cuff), which reduces blood loss.
You will be mobilized already on the first day after the surgery. From the first day onwards, you will be allowed to apply full weight to your leg using walking sticks. You will be able to stop using walking sticks after 3-4 weeks. You will be discharged between the 5th and 8th day following the surgery. The range of motion will be increased to over 120° in the first six weeks with the help of physiotherapy. Full extension is usually achieved with a slight delay.