What is gonarthrosis?

In knee joints, a severe abrasion of the cartilage to the bone is called gonarthrosis. It is now the most common disease of the knee joint.

Increased body weight might play a role in the formation of arthrosis. But also congenital or acquired malpositions of the legs, as well as instabilities or injuries lead to wear and tear of the cartilage. Meniscus damage, torn ligaments, unilateral loads and other factors increase the risk of developing gonarthrosis.

How to notice osteoarthritis of the knee? What are the typical symptoms?

With gonarthrosis there are various complaints: slightly noticeable pain in the knee during movement and sometimes when resting. The mobility of the knee is significantly limited. Swelling, muscle tension or even audible joint grinding occur. In all cases, an experienced physician should be consulted.

How can gonarthrosis be diagnosed?

Clinical examination and state-of-the-art imaging such as ultrasound, X-ray, DVT, CT and MRI reveal information about the extent of cartilage damage and the severity of arthrosis.

Can arthrosis of the knee be treated without surgery? 

Conservative therapy involves physiotherapeutic measures and the use of medication. Injections or autologous blood (ACP) therapies reduce pain in the knee, but cannot significantly stop the progression of the disease. The most effective conservative measures are weight reduction and sports. High-impact sports, such as soccer and squash, should be avoided; in their place, it is better to practice low-impact sports, such as cycling, rowing, swimming, walking, cross-training, and stepping. It is important to exercise in the low level of pain.

Which therapy methods are recommended?

Because gonarthrosis is a wear and tear of the joint that has often left visible damage, it may be recommended to clean out the knee joint using knee arthroscopy – especially if mechanical blockages (e.g., free joint bodies, interfering bone edges, pinching meniscus or cartilage) are found. If the gonarthrosis is already severely advanced, this method will not be very helpful. In that case, the worn joint surface can be partially (sled prosthesis) or completely (total knee arthroplasty) crowned. Depending on the severity of the gonarthrosis, the experienced specialist must determine which therapy is optimal. In both cases, the patient can recover quite quickly and return to active daily life.

Why it is important to do muscle training after the surgery?

Mobilization is started directly after the operation. During rehabilitation, the patient executes a special program focused on the new joint.The surrounding musculature is strengthened to avoid malpositions.

Do you have any further questions?

Would you like to learn more or are you directly affected? Then feel free to contact our experts. They will be glad to help you.

Why is cartilage damage to be taken seriously?

Untreated joint cartilage defects are problematic because the regeneration of a cartilage proves to be difficult. Today, it is known that injured or destroyed cartilage does not regenerate or grow back to its original shape. Instead, it results in poor quality scar tissue if the cartilage is not treated. Since fibrocartilage is very soft, it tends to wear out rapidly and this can cause arthrosis.

How do you notice cartilage damage in everyday life?

Typical symptoms of cartilage damage in the knee include pain and limited mobility. Depending on the degree of the defect, swelling of the knee may also occur or it may hurt at rest. Crunching and cracking sounds can be heard from time to time. The knee can also lock completely and should then be examined by a specialist at the latest.

What causes cartilage damage?

Causes of traumatic cartilage damage are injuries or accidents, e.g. during physical sports (soccer, handball or ice hockey), but also leisure sports (skiing and snowboarding). Enormous forces are often exerted on the joint, which can lead to cartilage injuries. Severe traumatic cartilage damage occurs frequently, even in the case of fresh anterior cruciate ligament rupture or patellar dislocation. In this case, a piece of healthy cartilage (possibly with bone) can break out of the joint surface, which is known as a chondral or osteochondral flake. Degenerative cartilage damage, on the other hand, can occur as a result of natural wear and tear (genetic influence, stress over decades), with more extensive abrasion of the cartilage covering.

During the clinical examination, how do you recognize a cartilage defect?

With the help of imaging techniques (MRI), cartilage damage can be diagnosed and the appropriate therapy found.

Is it necessary to operate at this point?

No, cartilage damage can often be treated conservatively for years. Therapeutic treatment includes, for example, targeted physiotherapy, cartilage preparations (hyaluronic acid), the body’s own repair enzymes (ACP), medication with an anti-inflammatory effect, and lifestyle adjustments (sports activities, weight).

But when is surgery indicated?

If deep, so-called „cartilage holes “ are present in young patients, surgical treatment is recommended, to prevent a rapid progression to the final stage of arthrosis.

So what to do with freshly sheared cartilage-bone fragments?

After severe knee injuries, a fragment of bone and cartilage may be torn off from the joint surface. X-rays, DVT, CT and MRI can detect this in most cases. With timely surgery, avulsed bone-cartilage fragments can be replaced and fixed in place. Successful restoration of the joint surface is the optimal therapy.

What´s about arthroscopic cartilage cell implantation (ACI)?

Annually, we have more than one hundred minimally invasive cartilage cell transplantations on the knee, making us one of the most experienced cartilage specialists in the world. As early as 2006, we were one of the first centers in Germany to adopt a new approach to autologous cartilage cell transplantation. The procedure, developed by the company co.don® AG (Berlin), makes it possible to implant the cartilage cells in a minimally invasive manner, i.e. arthroscopically. For this purpose, a piece of cartilage only a few millimeters in size is first removed from an area of the knee joint that is subject to little stress in order to cultivate the cells.

How exactly does it works?

In the laboratory, the cartilage cells are combined into three-dimensional spheres (spheroids), with each individual spheroid containing about 200,000 cartilage cells and having a size of only 0.5-0.7 mm in diameter, depending on the degree of maturity. The 3D spheroids are produced exclusively with the patient’s own blood, thus avoiding foreign proteins and side effects.

As soon as the spheroids are in contact with the prepared cartilage defect site during implantation, they are able to stick to the subchondral bone in a mechanically stable manner due to adhesive proteins. In many cases, we treat several defects at the same time by means of cartilage cell transplantation.

How is the cell inserted?

Surgical techniques have now been improved so that the operation can be performed with minimally invasive techniques. The cells are transplanted into all areas of the knee joint, e.g. the femoral condyle, the tibial plateau and also the area of the kneecap.

Scientific research: what does it say? What results can be recorded?

Over the past decades, more than 800 patients with spheroids have been successfully treated with arthroscopic surgery. All patients are followed up after surgery – the clinical results are very satisfying in most cases. In several patients we were able to perform arthroscopic follow-up examinations of the transplanted cartilage after six weeks, four months, nine and 18 months.

Complete defect coverage by the cartilage graft was found in 91% (see published studies). MRI images underline the good clinical results.

What is microfracture and what are its benefits?

During arthroscopy, small holes are drilled into the bone in the area of the cartilage defect using a pointed awl. So stem cells are released from the bone marrow (spongiosa) behind. There is hemorrhage from the bone into the defect area. The blood stem cells stick to the site of microfracture. With relief of the knee joint, these stem cells develop into fibrocartilage after a few months and fill the circumscribed cartilage defect. In many cases, the patient is largely free of pain and able to bear weight for some time.

An advantage of the procedure is that it can be used immediately during arthroscopy. The disadvantage is that only fibrocartilage of poor quality is obtained.

And what is the alternative to microfracturing? 

In this procedure, the exposed bone is refreshed with a milling cutter (arthroscopy). This results in the flushing out of stem cells into the defect area and a regenerate of fibrocartilage can develop.

What is the AMIC procedure?

The AMIC procedure is a further development of microfracturing. What exactly is meant by it and what advantages it has for the patient are explained in this section.

What is mosaicplasty?

In mosaicplasty, the cartilage defect together with an underlying cylinder is punched out in a round shape and replaced by a second autologous round cylinder with an intact cartilage surface. The procedure is demanding and very sensitive and requires precise surgery with exact reconstruction of the joint cartilage level.

Do you have any further questions?

Would you like to learn more or are you directly affected? Then contact Prof. Siebold and Prof. Becher directly. They will be glad to help you.

Where exactly is the meniscus located and what is its function?

The meniscus tissue is elastic and lies like a disc between the femoral condyle and the tibial plateau. There is an inner and outer meniscus. The cartilaginous meniscus tissue is the most important buffer during impact loads on the knee.

The meniscus has many functions. By increasing the surface area, the total load is divided on the knee joint. It is responsible for the arsorbtion, for the synovial fluid and stability of the knee joint. This makes the menisci in the knee joint the most important protection for the articular cartilage.

Whats the material specificity of the meniscus?

The meniscus has a dense fibrous tissue that is supplied with blood only at the edge to the joint capsule. This zone is called the red-red zone. There are no nerve fibers and therefore no pain is initially felt with degeneration or injury. However, a degenerative or acute rupture of the meniscus causes displacement and entrapment of meniscal tissue. Weight bearing changes and irritation of the synovial membrane occurs.

Why does a meniscus tear and can it heal again?

Fresh meniscal tears in young patients usually have a good chance of healing. Of course, healing depends on the shape of the tear. Every tissue is subject to natural aging, including the meniscus tissue. Genetic factors play an important role here. The natural aging process is obviously affected by the degree of stress in everyday life.

What are the differences?

Generally poor blood supply to the meniscus means that only healthy meniscal tissue has a sufficient chance of healing in young patients. Tears close to the capsule as well as a meniscus tear in combination with an ACL injury have particularly good healing prospects. In the case of degenerative changes, however, it becomes difficult because there is no healing and thus no reduction in pain.

Which are the consequences of a meniscus tear for the knee joint?

An acute or degenerative meniscus injury should in any case be clarified by a knee specialist in order to initiate an early individual therapy.

Ruptured meniscus leads to a disturbed sliding surface between the upper and lower leg. It can also entrap loosened parts of the meniscus, causing high stresses between the cartilage of the upper and lower leg and destroying the sensitive cartilage surface.

What happens to the cartilage surface if a ruptured meniscus is not repaired?

The once very smooth surface of the cartilage becomes dull and softened. That‘ s the starting point for a gradual defibration and abrasion of the cartilage. We speak of arthrosis when the cartilage has worn down to the surface of the bone. The wear and tear can go unnoticed for a long time until it finally triggers pain.

Why do especially athletes have problems with the meniscus? In what way does a tear occur? 

Sportsmen and women often suffer an acute meniscus tear as a result of excessive stress on the meniscus. Patients usually describe a stabbing pain in the knee. Fresh injuries often lead to an acute functional limitation in sports or to a permanent inability. Due to the complaints, the diagnosis of the meniscus lesion is made at an early stage and surgical therapy is initiated immediately. If the fresh meniscus injury is not treated, mechanical irritation and pinching of the meniscus can cause damage, as well as damage to the articular cartilage with early arthrosis.

What are the symptoms of a meniscus tear?

With degenerative tears of the meniscus, the process develops gradually, so that disorders are only noticed after a while. An accident does not always have to be the cause.Everyday stress, e.g. getting out of the car or going into a deep squat, is enough to suddenly trigger pain from the already degenerative meniscus.

On what do you have to pay attention?

If a flap tear or a basket handle tear occurs, acute painful locking of the knee joint with restriction of the range of motion may occur. In most cases, there is a painful inhibition of extension, which can be temporarily relieved by certain rotational movements with reduction of the meniscus. A snapping of the meniscal flap is also described by the patient. Everyday loads can be performed on meniscal tears, but patients in jobs where they have to stand a lot complain of pain in the area of the inner or outer joint space. Heavier loads result in more pain with irritation and effusion in the knee joint. There is also often local overheating of the knee joint.

What exactly does the orthopedist examine?

The diagnosis can be made by a specific clinical examination in the area of the inner and outer meniscus. In addition, standardized X-ray images taken while the patient is standing. Also the exclude bony causes of the complaints and to determine the degree of arthrosis. Magnetic resonance imaging (MRI) is certainly the most reliable method to visualize a meniscus tear. From our point of view, an exact diagnosis of the meniscus injury is necessary to initiate the appropriate individual therapy.

Is it possible to avoid surgery?

If the patient is free of symptoms, a conservative (non-surgical) therapy can be attempted with physiotherapy and appropriate medication. Especially in older or less active patients, surgery can often be avoided.

When is an endoscopy (arthroscopy) necessary?

In most cases, however, there are persistent complaints in everyday life, which limit the quality of life significantly. It is then recommended to perform a knee arthroscopy. This allows excellent visualization and examination of the articular cartilage and menisci while treating the damage. Basically, it is important to preserve as much functional meniscal tissue as possible in order to reduce the long-term consequences of meniscal surgery. For this reason, preserving the meniscal tissue as much as possible by suturing it is absolutely necessary.

Tear in the meniscus – how to repair it?

We have a variety of different suture techniques and are very familiar with meniscus suturing. Only this allows for optimal fixation of the torn meniscus and creates optimal healing conditions.

Especially in the case of a basket handle tear, preservation of the meniscus is reasonable, since removal of the large basket handle flap would otherwise be equivalent to extensive meniscus removal.

What if the meniscus has to be (completely) removed?

Patients who lose their meniscus in an accident at a young age may develop early arthrosis in the medium term. This is often combined with the early onset of painful cartilage damage of the femoral condyle and the tibial plateau. Pain and bruising in the knee joint are the first signs of the development of arthrosis and an important indication of early overloading of the joint section.

What exactly is a meniscus transplant?

An important surgical procedure in this situation is the transplantation of a donor meniscus. Both the inner and outer meniscus can be replaced. The donor meniscus is ordered from internationally accredited tissue banks. It comes from deceased accident victims who had agreed to the removal. A rejection reaction is unusual.

The donor meniscus is removed under sterile surgical conditions and then tested under internationally accepted criteria for pathogens. The risk of transmission of an infectious disease is extremely low, but cannot be excluded. After appropriate storage and complex transport, the meniscus transplantation is performed minimally invasively during a joint endoscopy. The operation is complex and takes about 2 hours. We are very familiar with the technique of meniscus transplantation since more than 10 years and perform about 15-20 meniscus transplantations per year for private and health insurance patients. All meniscus transplantations are performed by Prof. Siebold.

What is the scientific status and what are the success rates?

Clinical studies show a significant reduction in pain and very good healing of the donor menisci, and most patients do very well with the donor meniscus. Long-term studies also show that the clinical success rate with good cartilage conditions is about 80%. Under certain conditions, additional operations for leg axis correction may be necessary in order to achieve optimal relief of the damaged joint section and the donor meniscus.

Does it always have to be a donor meniscus? What about synthetic variants?

Because it is often very difficult to obtain a donor meniscus, intensive scientific work focuses on producing a synthetic implant to replace damaged meniscus tissue. The aim is to reduce pain and stimulate tissue growth in a damaged meniscus. The replacement tissue is sutured into the defect area of the inner or outer meniscus so that new, meniscus-like tissue forms and grows in. The implantation is minimally invasive, as a part of a knee joint endoscopy (arthroscopy). Currently, meniscus replacement implants are only suitable for a partial replacement of the meniscus and are not recommended for complete meniscus loss. Two different implants are available on the European market at the moment: „Actifit“ and „Menaflex“ (formerly: CMI – Collagen Meniscus Implant).

What happens after the surgery, how long does mobilization last?

After partial removal of the meniscus, full weight-bearing can already be performed on the day of surgery, with appropriate joke-oriented transition. One can use forearm walking sticks. Physiotherapy is recommended in the first weeks after the surgery. Office activities can be resumed after about 1 to 2 weeks. In the case of physical activity, it takes a few more weeks before the patient can return to active daily life.

And after the transplant/ graft?

After meniscus transplantation, the partial loading phase is extended to 5 to 6 weeks, otherwise there are no significant differences compared to meniscus suturing. After implantation of meniscus replacement tissue (e.g. ACTIfit), approx. 6 weeks of partial loading are necessary.

Which sports are possible?

After a partial meniscus removal, the knee can be carefully loaded without crutches already on the day of the operation. Cycling is possible after a few days if healing proceeds normally. Swimming follows about 3 weeks postoperatively after wound healing is complete. Jogging and stop-and-go sports (e.g. soccer) are not recommended until three to four weeks after surgery.

What about sports activity after a meniscus suture?

After meniscus suturing, sports rehabilitation can be delayed by several weeks. Here we recommend sports after 4-6 weeks at the earliest. Cycling and swimming are recommended. Movements like squatting should be avoided for at least 3 months to prevent bruising of the meniscal suture. Intensive sports should not be practiced in the 5-6 months after surgery.

And what about sports after a meniscus transplant?

After transplantation of a donor meniscus as well as implantation of meniscus replacement tissue, a return to light sports is possible after 5-6 months. Initially, we recommend cycling and swimming. The return to intensive sports must be carefully considered and is possible after 10-12 months at the earliest.

Through regular clinical checks and a slow build-up of the physical strain, a return to sports is possible in most cases. However, after meniscus transplantation ot the implantation of meniscus replacement tissue, competitive sports are only possible in exceptional cases.

Do you have any further questions?

Would you like to learn more or are you personally affected? Then contact Prof. Dr. Siebold directly. He will be glad to help you.

What is the anterior cruciate ligament? And how does it get injured?

The knee joint is stabilized by the anterior and posterior cruciate ligaments. Especially sports accidents such as soccer or skiing, but also other twisting and falling injuries can result in a cruciate ligament rupture. It can lead to instability in the knee joint with unsteadiness („giving way“), pain and swelling. An untreated cruciate ligament tear often means the end of sports. Further damage to the meniscus and cartilage leads to painful swelling, to an irritable knee and finally to arthrosis. That is why „cruciate ligament replacement“ = „cruciate ligament plastic surgery“ is now standard in the treatment of cruciate ligament tears to restore knee function and protect the meniscus and cartilage.

Which treatment is most useful for ligament rupture?

A suitable cruciate ligament replacement is crucial. Everyone from sports professionals to hobby athletes are treated with the individual surgical technique. The surgery preserves as much original cruciate ligament tissue as possible to improve proprioception and rapid healing. A partial tear of the anterior cruciate ligament is followed by a partial replacement of the anterior cruciate ligament (also called augmentation). Depending on the patient and sport, the semitendinosus tendon, patellar tendon or quadriceps tendon are used as grafts. A knee joint endoscopy requires only a few small incisions and is thus one of the gentlest procedures.

What is special about double bundle reconstruction and flat cruciate ligament reconstruction?

Only since a few years it is known that the anterior cruciate ligament is flat instead of round. It ultimately looks like a wristband and is about twelve to 15 millimeters wide with a thickness of only three to four millimeters. Own anatomical studies could prove this. For this reason, a flat reconstruction of the cruciate ligament with the semitendinosus tendon (knee flexor tendon) using the double-bundle technique is an ideal option. A wide but flat reconstruction is created that closely resembles the anatomical shape of the cruciate ligament. This technique also has biomechanical advantages compared to the usual single-bundle technique. Therefore, we successfully use the double-bundle reconstruction of the ACL. Clinical follow-up examinations of patients show excellent knee stability with very high patient satisfaction.

Why choose the semitendinosus tendon as a replacement?

In 2018, we introduced a new surgical technique in which the semitendonous tendon is used as a flat cruciate ligament replacement. The new surgical method is innovative and very close to the natural cruciate ligament anatomy. It is the answer to the flat cruciate ligament anatomy and is a good alternative to the double bundle technique.

What is meant by a partial tear or partial rupture of the anterior cruciate ligament?

In the case of a partial tear of the anterior cruciate ligament, there is still rest stability in the knee joint. But sports that put a lot of pressure on the knee, such as soccer, handball, etc., with a lot of twisting and stop-and-go movements, can no longer be practiced. This is why partial reconstruction of the anterior cruciate ligament by surgery is useful in cases of instability, to strengthen the cruciate ligament. We use the double-bundle technique, keeping most of the cruciate ligament fibers that are still intact. The procedure is known as augmentation, and we are one of the few centers in the world that have used this technique for years. This provides the proprioception, the rest stability and the vascular supply of the original cruciate ligament and helps to achieve a rapid recovery.

When is the right time for surgery?

The right time is different for each patient. It depends on various factors. Ideally, there should be a good range of motion and low pain before surgery, because then the patient can rehabilitate quickly after the operation. The most feared complication after surgery of the anterior cruciate ligament is the postoperative reduction in flexion and extension (arthrofibrosis), which extends the rehabilitation period and often requires anesthesia mobilization or even further arthroscopic surgery. Considering the above criteria, the risk of arthrofibrosis is low.

Which graft is the right choice and what about returning to sports?

For young soccer players, professional soccer players and competitive athletes, we use the patellar tendon as a replacement. The patellar tendon graft grows in with its 2 bone blocks within 8 weeks and allows a early return to play after about 6-8 months possible. However, this is only possible with optimal daily rehabilitation of several hours(!) and professional athletes. The use of a patellar tendon can cause pain and numbness in the treated area below the kneecap. This is why tendon removal is not suitable in knee-active professions, such as tilers or kindergarten teachers.

A very good alternative to the patellar tendon is a knee flexor tendon = semitendinosus tendon. Today, we usually only remove the stronger semitendinosus tendon and spare the gracilis tendon. The removal of the knee flexor tendon usually does not cause any problems at the removal site and is very well tolerated. Also, the tendons can grow back within a year to a certain extent. With the semitendinosus tendon, we reconstruct the two parts of the anterior cruciate ligament using the so-called double bundle technique and can also perform a partial reconstruction (augmentation). This surgical technique is also ideal for competitive and ambitious athletes, because it restores the biomechanics very well and the durability is very good.

Depending on the sport and the patient, we also like to use the middle third of the quadriceps tendon. It is also an excellent graft but requires another skin incision above the patella. It is especially useful for patients who kneel a lot, whether at work or in sports.

Finally, we offer the possibility of using a donor tendon (allograft) for cruciate ligament replacement. This must be ordered from a tissue bank. Donor tendons are used especially in complicated revision surgeries and multiple ligament injuries.

And what to expect after the surgery?

We recommend an approx. 2-day stationary stay with medical supervision by our medical team for cruciate ligament replacement. Our experienced physiotherapists start rehabilitation already on the ward. Individual physiotherapy takes place twice a day and involves mobilization with walking exercises. Lymphatic drainage reduces soft tissue swelling. The offer of physiotherapy on Saturdays and Sundays is probably unique.

Do you have any other questions?n?

Would you like to learn more or are you personally affected? Then contact Prof. Dr. Siebold directly. He will be glad to help you.

A large number of knee joint diseases affect the joint between the kneecap (patella) and the femoral condyle (femur), the so-called „patellofemoral joint“.

What are the reasons for pain in the kneecap?

Patellar complaints are often triggered by a bony congenital deformity of the patella or the sliding bearing. As a result of the deformity, a „misalignment“ of the patella develops with overpressure of the cartilage, pain, swelling and increasing cartilage damage. The patella can also slip out of the bony sliding bearing, which is called patellar dislocation or luxation. A (sports) accident can also lead to patellar luxation.

What is cartilage damage of the patella? 

Malalignment of the kneecap or instability can cause pressure on the cartilage. Over time, this can result in cartilage damage developing behind the kneecap and in the femoral condyle, which can eventually lead to arthrosis. X-ray and magnetic resonance imaging precisely identify the cause. Furthermore, the severity of cartilage damage can be easily determined.

Does cartilage damage to the patella require surgery?

Not necessarily. Often, physiotherapeutic treatment can improve the symptoms and even eliminate the pain. Sports that reduce the strain on the kneecaps are cycling with a high frequency and less resistance (so-called spinning), crawl swimming, aqua jogging, paddling, Nordic walking etc.

The injection of hyaluronic acid preparations, which have a kind of lubricating effect, has proven more and more successful. It is also possible to inject „repair enzymes“ (ACP), which have a positive effect on cortex stabilization. Taking food supplements like glucosamine and chondroitin sulfate also has an effect.

And what is the surgical method for cartilage damage to the patella?

Arthroscopic cartilage cell transplantation is performed to repair deep cartilage holes. A detailed description of the different surgical cartilage therapy procedures can be found under the heading cartilage damage.

Regarding the instability of the patella – how can it be treated conservatively?

When the patella is first dislocated, a ligament can tear (= medial patellofemoral ligament or abbreviated MPFL), which is crucial for the stable guidance of the patella. Conservative therapy without surgery involves strengthening the thigh muscle (M. quadrizeps) as well as coordination training by means of physiotherapy.

How to treat it surgically?

Indications for surgical intervention for patellar instability include: bony deformities of the patella or gliding bearing (also called dysplasia), recurrent instability, young active patients, cartilage damage, or torn free joint tissue.

When is a so-called MPFL used?

The medial patellofemoral ligament – or simply called MPFL – is a strong internal capsular reinforcement that runs from the edge of the patella to the femoral condyle. It stops the patella from popping outward from its sliding bearing during knee extension. Anatomical and biomechanical studies show the outstanding importance of the method as the most important stabilizer for the patella. The MPFL reconstruction has therefore proved to be very successful. The aim of MPFL reconstruction is to fix the patella back in the joint, repair any cartilage damage that has occurred in the process and limit further damage.

What is a MPFL surgical technique?

MPFL replacement has become the most modern and successful surgical procedure in recent years. In this procedure, the medial patellofemoral ligament (MPFL) is replaced by an autologous knee flexor tendon, the gracilis tendon. The tendon is inserted as a graft at the site of the torn MPFL and is secured by absorbable implants. The operation is a minimally invasive surgical technique.

What is special about arthroscopic MPFL replacement?

Compared to the open technique, we perform MPFL replacement arthroscopically. We have developed our own surgical procedure for this. First, the MPFL is arthroscopically visualized on the patella and thigh. An exact understanding of the anatomical course of the MPFL is a necessary for this. With acute but also with recurrent patellar dislocation, the remains of the MPFL can be seen clearly as a broad but thin ligament. An arthroscopic replacement gracilis tendon is then pulled in and attached to the patella without implants and to the thigh with a bioscrew.

What are the main benefits?

Advantages of the arthroscopic approach are less trauma compared to the open approach, an individual anatomical reconstruction by exact arthroscopic visualization of the MPFL at the patella and femur, and a better aesthetic result due to smaller incisions at the patella. Recovery is easier due to less wound pain.

What rehabilitation measures does the patient face?

After surgery, pain-oriented range of motion can be increased to achieve free flexion after approximately 3-4 weeks. A motorized splint helps to speed up the rehabilitation process. In our opinion, partial weight-bearing is useful for about 2-3 weeks.

What are the scientific results on MPFL reconstruction?

Current studies on MPFL reconstruction show good to very good clinical results. The re-luxation rate is less than 4% (Christiansen et al 2008, Watanebe et al 2008, Mikashima et al 2006, Steiner et al 2006). This makes the surgical procedure very successful compared to other stabilizing procedures on the patella with reluxation rates of 10% -35% (Davis and Fithian 2002). The clinical and functional outcome, as measured by the Kujala score, is also convincing.

Do you have any further questions?

Would you like to learn more or are you directly affected? Then contact Prof. Siebold and Prof. Becher directly. They will be glad to help you.

Can children and adolescents have an ACL injury?

Injuries to the anterior cruciate ligament are also common in children and adolescents, particularly as a result of sports.

There are two main types of cruciate ligament injuries in children: On the one hand, there may be a direct tear of the cruciate ligament fibers in the joint and on the other hand – and this is typical for children – there may be a rupture of the anterior cruciate ligament on the tibia. In both cases, the knee joint is unstable. Through a precise clinical examination compared to the healthy side and according to x-rays and magnetic resonance images, the expert physician can make a definite diagnosis.

What is the cruciate ligament replacement and how can it be treated?

Based on clinical experience, early recovery of stability is necessary to avoid damage to the cartilage and menisci at an early stage. Unfortunately, stabilization by muscle training alone is usually not sufficient. Only ACL surgery can restore the functionality of the knee joint and protect the knee joint from early wear and tear and arthrosis. Therefore, a pediatric cruciate ligament injury in children and adolescents should be treated surgically in case of instability of the knee joint.

What is so special about childhood and adolescence?

The specific things in children and adolescents are the open growth plates. If there is a bony avulsion of the anterior cruciate ligament on the tibia, the avulsed bone fragment should be reattached in an arthroscopic minimally invasive operation. This can be achieved very well without implants by using sutures. If the cruciate ligament is ruptured in the joint, a cruciate ligament replacement is recommended. For this purpose, we use the semitendinosus and gracilis tendon, which is pulled into the joint along the course of the original cruciate ligament tendons. Since the surgical technique requires the creation of drill channels on the tibial plateau and femur, it is important to treat the growth plates carefully. As long as important surgical rules are followed, no growth disturbance is expected. A novel surgical technique developed by Prof. Siebold for children and adolescents has significantly improved the durability of cruciate ligament reconstruction.

Do you have any further questions?

Would you like to learn more or are you personally affected? Then contact Prof. Dr. Siebold directly. He will be glad to help you.

What happens if the patella slides out of the plain bearing?