Primarius a. D. Dr. med. Wolfgang Zinser is an internationally recognized specialist in orthopedics and traumatology with particular expertise in joint-preserving hip surgery. As a certified cartilage specialist and recognized AGA expert for hips, knees and ankles, he has dedicated himself to the treatment and regeneration of damaged joints for over two decades. His focus is on hip arthroscopy, cartilage and labrum reconstruction as well as innovative procedures such as minimally invasive periacetabular osteotomy (PAO) for the correction of hip dysplasia. With more than 2000 cartilage cell transplants performed, Dr. Zinser is one of the world's leading experts in this field.
In his state-of-the-art OrthoExpert practice, he offers diagnostics and treatment at the highest scientific level and performs operations at the well-equipped Privatklinik Graz Ragnitz and EMCO Privatklinik Bad Dürrnberg/Salzburg. His primary goal is to provide his patients with individual, holistic and sustainable treatment - with a focus on long-term joint preservation and a quick return to an active life. As President of the Society for Cartilage Regeneration and Joint Preservation (QKG), Dr. Zinser is not only committed to the further development of innovative treatment methods, but is also active as a trainer, speaker and scientific author. His background in sports medicine as a former national track and field athlete in the triple jump gives him a deep understanding of the specific needs of athletes. In addition to surgical procedures, he offers a variety of modern conservative therapies, including PRP injections, hyaluronic acid therapies and cartilage-protective measures. His philosophy is based on precision, expertise and a personalized treatment approach.
By working closely with physiotherapists, sports associations and colleagues, he ensures that every patient receives the best possible care. Thanks to his status as an elective doctor, he can take enough time for each patient to develop a customized therapy. If you are looking for an experienced specialist for hip, knee and joint disorders, you are in the best hands with Dr. Wolfgang Zinser.
The editorial team of the Leading Medicine Guide spoke to Dr. Zinser about modern hip arthroscopy.
In recent years, hip arthroscopy has established itself as a minimally invasive technique for the diagnosis and treatment of various hip joint disorders. It is mainly used in younger and athletically active patients who suffer from pain or restricted movement. Typical indications are femoroacetabular impingement (FAI), cartilage damage or labral tears. Early screening and targeted prophylaxis can often prevent hip problems and joint wear and tear or slow down their progression.
When determining the indication for hip arthroscopy, in particular for femoroacetabular impingement (FAI) (hip impingement) and labral lesions (damage to the hip joint labrum), both clinical and imaging criteria must be carefully considered.
“For joint-preserving therapies, there are standardized recommendations for imaging, whereby several x-rays are always taken to calculate all angular dimensions. A central component of hip diagnostics is the standardized pelvic overview image WITHOUT gonadal protection and axial imaging, e.g. the Lauenstein image, which provides detailed information about the hip joint structures and helps to identify pathological changes such as osteoarthritis, dysplasia or impingement. Other important imaging techniques in axial imaging are the Ripstein and FAUX profile image (lateral standing image), which each show specific aspects of the hip joint and enable precise assessment of various hip diseases. The X-ray is the basis for the assessment of hip joint structures, particularly in the diagnosis of dysplasia and femoroacetabular impingement (FAI). In order to differentiate between these two conditions, the angular measurements, which can only be precisely calculated using X-rays, are essential. Therefore, an X-ray is the first necessary examination before the MRI is used,” explains Dr. Zinser and continues:
“The MRI follows clearly defined guidelines set out in the European guideline recommendations. First, an overview image is taken, followed by specific sequences, e.g. the hip joint sagittal and coronal sections as well as radial sequences around the femoral neck axis. This radial technique, in which a virtual axis is drawn through the femoral neck and rotated 360 degrees around the femoral head, makes it possible to detect irregularities such as a cam deformity. The exact location of this cam deformity can only be precisely visualized using MRI. In young patients suspected of having an incorrect femoral neck rotation (torsion), it is also recommended to calculate the antetorsion angle of the femoral neck in the MRI (angle between the femoral neck axis and the axis of the posterior knee baseline). It is important that all these standard examinations are carried out, as an incomplete diagnostic picture can lead to misdiagnosis. For example, if only the MRI is used, dysplasia could be missed, which in the worst case could lead to less than optimal or even incorrect treatment. A common example is when patients come in with a diagnosis of a labral lesion and believe that the labrum simply needs to be sutured. It is important to explain that a labral lesion in the hip does not simply occur in isolation, but always has an underlying cause. This can be femoroacetabular impingement (FAI), hip dysplasia or a combination of both. If only the labrum is refixed without treating the underlying cause, for example during a hip arthroscopy, the problem will not be solved in the long term and the patient will continue to have complaints."
Dr. Zinser has been passionately committed to joint and cartilage regeneration for over twenty years, both nationally and internationally. With his extensive knowledge and expertise, he supports the further development of this specialist field and is actively involved in numerous medical societies to promote the latest findings and innovative treatment methods.
“As a trainer, it is important to me to pass on my knowledge to young doctors and to accompany them on their way. The close exchange with colleagues from different fields helps to develop new approaches. A central concern of my involvement in specialist societies is education: joint-preserving hip therapies belong in the hands of specialists. Unfortunately, many patients only receive the correct diagnosis at a late stage - for example in the case of hip dysplasia, where years often pass and several orthopedic specialists are consulted before the causes are identified. The necessary measurements are often not taken at an early stage, which delays the diagnosis. In the case of FAI, referral to specialists is usually somewhat quicker, but here too, education remains essential,” explains Dr. Zinser and adds:
“In Germany, there is currently an increased focus on the centralization of clinics, which means that specialized centers are bundled together to ensure more comprehensive care. Even if patients may have to accept longer travel times, this is a sensible step, as all relevant specialties can work together in large clinics, which optimizes treatment. The size of the center plays less of a role, especially when it comes to procedures such as hip arthroscopy, some of which are even performed on an outpatient basis in Germany. No intensive care units are required for this procedure, just the necessary specialist knowledge, surgical skills and a competent radiologist on site."
Femoroacetabular impingement (FAI) is a common, pre-arthritic hip deformity in children and adolescents who are active in sports. It is usually caused by overloading during the growth phase, particularly in sports with high hip loads such as soccer, ice hockey or basketball. If left untreated, a cam-FAI significantly increases the risk of premature coxarthrosis. Timely diagnosis and treatment - such as hip arthroscopy - can significantly improve the prognosis and prevent osteoarthritis. Intensive training phases between the ages of 12 and 13 are particularly risky. Studies show that frequent strain, epiphyseal injuries or pre-existing conditions such as Perthes' disease can contribute to the development. While symptomatic cases should be operated on early, monitoring of asymptomatic deformities is also important to avoid late complications. In the DACH region, there is an underuse of FAI diagnostics and treatment compared to the USA. Greater education, better reimbursement for joint-preserving procedures and targeted prevention programs are needed to reduce long-term damage and the number of joint replacement operations.
The functional and long-term results of hip arthroscopy vary considerably depending on the age of the patient, with younger and older patient groups in particular showing different postoperative courses and prognoses.
Younger patients, especially those under the age of 40, generally benefit the most from hip arthroscopy, especially if they have femoroacetabular impingement (FAI) or labral lesions but do not yet have significant degenerative changes in the joint.
“Statistically, all studies show that the younger the patient, the better the prognosis. This is because femoroacetabular impingement (FAI) develops during puberty and progresses since then. Depending on how active the patient is, the situation can develop differently. If someone does little sport or hardly moves at all, so that the typical movements in which the bone bumps against the joint structures or becomes trapped do not occur, they can often live with FAI for a long time without major symptoms. More active patients, on the other hand, experience increased symptoms with increasing stress on the hip because the deformity increasingly damages the joint structures. The longer someone lives with this damaging deformity, the greater the damage that can be detected in the joint. It is best if the FAI is corrected at a stage when there is little or no damage to the joint structures. There is good scientific evidence that early treatment of patients significantly improves their chances of having a healthy hip joint in later life and prevents age-related wear and tear,” says Dr. Zinser. The main aim of treatment is therefore prevention. Young, athletically active people who struggle with non-specific complaints in the groin area are often particularly affected. These patients often think that they simply have a groin strain or sore muscles. In reality, it is usually the hip that is causing problems.
“Many patients report protracted complaints that they initially dismiss as overuse. However, closer investigation often reveals earlier symptoms such as adductor pain after sport, which could have been recognized as the first warning signs. Increasing hip stiffness and limited mobility are also frequently reported - complaints that are wrongly explained as muscle shortening. However, the cause of FAI actually lies in the bony structure: “When stretching, the bony tuberosity pushes against the joint, which can cause further damage and worsen the symptoms,” explains Dr. Zinser.
Preventive measures and conservative treatment options play a decisive role in slowing down the progression of degenerative hip diseases and delaying surgery as far as possible.
If a patient has a symptomatic FAI, i.e. experiences symptoms over a longer period of time, and these do not improve despite at least three months of conservative treatment, then, according to current knowledge, surgery should be considered. Especially if certain angles of the hip joint are pronounced. “A study shows that the risk of developing radiographic osteoarthritis within the next 13 years increases by 5% with each additional degree for an alpha angle above 65 degrees, which is typical for CAM-FAI. At an angle of 66 degrees, the risk would already be 5% higher, at 67 degrees 10% higher and so on. Over the course of a lifetime, the risk of needing an artificial hip joint increases by 4% with each additional degree of the alpha angle. This means that early treatment can reduce the risk of deterioration and therefore also the risk of needing a hip prosthesis later on.Symptomatic patients, especially younger ones, should therefore be operated on today if conservative therapy is unsuccessful. In cases with less pronounced FAI, where the symptoms are mild and conservative therapy, for example physiotherapy, leads to freedom from symptoms, it is possible to wait and see. If patients do not engage in intensive sporting activities and their symptoms disappear with physiotherapy, surgery is not immediately necessary. However, as soon as symptoms reappear, treatment should be initiated. If conservative treatment over a period of three months does not bring any improvement, a more detailed examination should be carried out to observe the progression,” Dr. Zinser clarifies and comments on the physiotherapy options:
“Physiotherapy usually recommends a special program that is carried out twice a week. The aim is to reduce the bumping between the femoral neck and the socket - among other things by straightening the pelvis to avoid a hollow back and by stretching the often shortened hip flexor. These measures can often provide relief or even eliminate symptoms in mild cases. Exact figures on the success of conservative therapies are not available. If the pain persists despite therapy and the pain continues to occur in everyday life or during sport, surgery should be considered in order to avoid consequential damage."
Hip arthroscopy, joint-preserving osteotomic procedures (correcting the bony disorder) and conservative therapies offer different benefits and each have their own strengths in terms of pain relief and functional improvement, depending on the severity of the condition and the specific needs of the patient.
Hip arthroscopy is a minimally invasive procedure in which small incisions are made to inspect the joint and remove any damaged cartilage areas or free joint bodies. In cases of early to moderate hip osteoarthritis, where there is only limited damage to the cartilage or other tissues, hip arthroscopy can be a good option. “When treating FAI (femoroacetabular impingement), it is crucial to resolve the impingement and the associated discomfort. Generally, hip surgery involves corrections to the rounded femoral head (cam deformity) or/and the acetabulum to resolve the conflict. There are different techniques, but basically a small number of incisions are used to reach the joint. The exact number of incisions can vary depending on the complexity of the surgery - while some surgeons only need two incisions, my standard method involves three, and if additional cartilage needs to be processed, a fourth incision is made. The planning of the incision is precise to ensure that the procedure is performed optimally. Before the actual operation, the important landmarks of the hip joint are carefully marked. These include the anterior superior iliac spine and the midline of the knee joint. These landmarks help to precisely determine the direction of the incision so that the surgeon can ideally reach the joint. Even after performing over 2,000 hip arthroscopies, I continue to mark all the relevant points to ensure orientation during the operation, which I have become accustomed to as standard,” explains Dr. Zinser and then goes on to discuss the actual surgical incisions:
“The operation is performed in two phases. First, the patient is placed in a special position so that the leg is in a flexed position. This ensures that the anterior joint capsule is relaxed, allowing better access to the hip joint. In this first phase, the bumping of the joint is treated and the bony deformities are corrected by adjusting the area between the femoral neck and the acetabulum so that the previous pinching no longer occurs. During this phase, the joint is gently moved and positioned in various flexion positions until the problem is resolved. The second phase follows as soon as the impingement has been corrected. The aim of this phase is to move into the central hip joint. To do this, the extended leg is pulled further into a certain position to create a joint gap. The arthroscope can be inserted through this gap to inspect the joint, examine the cartilage of the femoral head and the acetabulum and detect any damage. If there are cracks in the cartilage, these are either repaired or smaller defects are removed. In the case of more severe cartilage damage, regenerative therapy can be used, in which, for example, a membrane is used to regenerate the cartilage."
In Germany, there are differences between inpatient and outpatient procedures, whereby the billing systems are still insufficiently adapted. There are no suitable billing codes for certain cartilage treatments such as matrix-induced bone marrow stimulation or outpatient cartilage cell transplantation, which leads to problems. The specialist society is currently working on solutions to improve the framework conditions.
Early detection and prevention of femoroacetabular impingement (FAI) is particularly important in sports such as soccer, ice hockey and martial arts, where the condition is common.
“It is important to me that FAI is systematically screened in the sports in which it frequently occurs. We are currently working with the coaches of Sturm Graz, the Bundesliga club nearby, to establish a prevention program. We know that almost 70% of footballers develop FAI over the course of their career - mainly due to intensive training during puberty. Footballers, ice hockey players and martial artists are particularly affected and have been frequently diagnosed with this problem. The first soccer club to implement a prevention program was FC Barcelona. The aim is to use screening methods to identify affected athletes at an early stage. For young players who have a rotation deficit, a targeted reduction in training or time off can help to reduce the frequency of FAI. The aim is to identify young athletes in at-risk sports in particular at an early stage in order to provide them with targeted help during the development of this problem. If symptoms continue to occur, we can treat them at an early stage. This is an essential part of our strategy. Screening, early detection and close monitoring of athletes are crucial, and we have already put these measures on the agenda in the committees,” explains Dr. Zinser.
After a hip arthroscopy, biomechanical and post-operative rehabilitation measures are crucial for optimal recovery and minimizing complications.
“In many cases, patients can go home on the day of the operation if home care is guaranteed. However, I recommend that patients stay in hospital for one night. They often have physiotherapy the next day and can then go home the day after that. This is the standard for me: surgery day, then physiotherapy the next day and home the day after that. Even if the operations are minor, they often take longer. A hip arthroscopy, for example, takes 1.5 to 2 hours on average - that's almost twice as long as inserting a hip joint. This is because hip arthroscopy is a much more complex procedure. In the past, this was done with open, large incisions in which the hip was dislocated and the joint structure was made directly visible. The arthroscopic procedure is much more difficult and requires a higher level of skill from the surgeon. There are studies that have examined the learning curves for such procedures, and it is recommended that at least 100-150 hip arthroscopies be performed under the guidance of an experienced surgeon in order to be able to master this technique safely,” states Dr. Zinser and adds the rules of conduct after the operation:
“Patients use walking sticks during the healing phase as a safety measure to avoid complications such as stress fractures of the femoral neck, which are rare but possible if patients put too much weight on the joint too early. In most cases, partial weight-bearing is maintained for around two to three weeks. When the walking sticks are no longer necessary, a more intensive rehabilitation phase follows. Our follow-up treatment is well documented and has already been published. The rehabilitation process comprises various phases. Initially, the main focus is on reducing swelling, joint mobilization, traction exercises and tension exercises. After the supports are removed, gait training, gait training and later strength training follow. A professional footballer who receives optimal therapy is fit again after around six months and can return to the game." We end our conversation with this positive outlook.
Thank you very much, Dr. Zinser, for the good clarification!
