Prof. Dr Clément M.L. Werner is a highly respected specialist in spinal and pelvic surgery who practises at the etzelclinic – Center for Minimally Invasive Surgery in Pfäffikon, Switzerland. With an impressive international background and extensive experience, he has specialized in particular in the sacroiliac joint (SIJ), the spine and the pelvis.
Prof. Dr. med. Werner has earned a first-class reputation in research and teaching through numerous scientific publications. As a renowned orthopedic surgeon, Prof. Dr. med. Werner treats conditions and injuries of the SIJ, the spine and the pelvis, which often severely impair the quality of life of those affected. He specializes in the treatment of chronic pain, which often occurs without a clearly identifiable cause and dominates patients’ daily lives.
His expertise in this field is based on extensive national and international training, including three fellowships in the USA and senior positions at the Balgrist University Hospital in Zurich and the University Hospital of Zurich, where he most recently served as Deputy Clinical Director. In recognition of his numerous scientific publications and book contributions, he was appointed Titular Professor in 2012.
Prof. Dr. med. Werner is not only an experienced surgeon but also a dedicated researcher. He strives to develop and optimize innovative treatment methods and surgical techniques in order to achieve the best possible outcomes for his patients. He has a particular interest in the sacroiliac joint, for which he has developed his own fusion implant that is inserted using a minimally invasive technique and allows the joint to bear full weight immediately after surgery. Since 2005, he has successfully performed over 700 SIJ operations and is therefore a sought-after speaker at scientific conferences. In addition to treating the sacroiliac joint, Prof. Dr. med. Werner is also an expert in osteoporotic fractures of the vertebral bodies and the pelvis.
At the etzelclinic, which is regarded as a flagship institution for high-performance medicine, Prof. Dr. med. Werner offers his patients the very latest minimally invasive treatment methods. This includes endoscopic treatment of nerve fibers, which can often relieve back pain without the need for spinal fusion surgery or implants. This is a particularly important option for patients whose daily lives are affected by chronic back pain. Prof. Dr. med. Werner attaches great importance to passing on his extensive knowledge to the next generation of doctors and supporting young medical professionals. He aims to convey his enthusiasm for the treatment of the musculoskeletal system, as he is convinced that only those who are passionate about their discipline can achieve excellence. He regularly holds training courses on the sacroiliac joint, both in Switzerland and Germany as well as internationally, and his patients’ gratitude for a life that is as pain-free as possible speaks for itself.
The editorial team at Leading Medicine Guide took the opportunity to speak with Prof. Dr. med. minimal Werner and was thus able to learn more about the sacroiliac joint.
The sacroiliac joint (SIJ) is responsible for the transmission of forces between the spine and the lower limbs and plays an important role in the stability of the pelvis and spine. It connects the sacrum to the two iliac bones and enables movements such as bending, twisting and flexing the trunk, as well as walking, standing and sitting. The sacroiliac joint is a structurally strong yet minimally flexible joint that helps to absorb and distribute the pressure and stresses that occur during walking, running or lifting. It also plays an important role in the transmission of forces between the upper body and the lower limbs during various movements. Furthermore, the sacroiliac joint acts as a shock absorber, absorbing impacts and vibrations that can occur when walking or jumping, and helps to reduce the load on the neighboring joints and structures. It contributes significantly to the stability, mobility and function of the entire pelvis and spine, enabling the body to move efficiently and pain-free.
Pain patterns with typical radiation in SIJ problems
Damage to the sacroiliac joint (SIJ) can have various causes and manifests itself through a range of symptoms.
“The causes of SIJ damage are manifold. In women, for example, hypermobility and extreme flexibility can lead to damage, as can, of course, the birth of large babies or multiple births. In men, the predominant cause is an accident, sometimes ankylosing spondylitis or fractures in the posterior pelvic ring. Then there is the large group of patients who have undergone spinal surgery and have had their spine fused from the lumbar vertebrae to the sacrum. Most spinal surgeons are familiar with the problems that arise in the adjacent segments following fusion. This is because, after a rigid spondylodesis operation, mobility in the fused vertebral segments is significantly restricted. This can lead to the adjacent, non-operated segments of the spine becoming overloaded over the years due to the fusion of the affected segment, causing them to wear out more quickly. The major problem, however, is that the lower end of the spine is largely ignored. From a biomechanical perspective, this is entirely logical, as someone with a fused spine exerts a disproportionately greater leverage effect on the next joint than someone with a mobile spine. Unfortunately, during training to become a spinal surgeon, one learns almost nothing about the SI joint. Trauma surgeons are more knowledgeable in this area and are also familiar with the surgical approaches, but they, in turn, do not treat SIJ patients,” explains Prof. Dr Werner at the start of our conversation, before going on to discuss the symptoms:
“The symptoms of sacroiliac joint damage are varied. Those affected usually complain of pain in the lower back and buttocks, i.e. in the area of the posterior pelvic ring, which can sometimes spread to the hips, the sides of the thighs or the sides of the calves. Patients also frequently describe nocturnal calf cramps. Around 20–30% also experience pain in the groin region. Consequently, damage to the SIJ is often mistaken for a disc problem, a hip problem or a hernia. Sitting, particularly for prolonged periods, can be painful in the posterior pelvic region. Patients may also find it difficult to lie on the affected side, and standing up from a sitting or lying position is difficult. Symptoms can even occur when walking or standing, often accompanied by a ‘feeling of instability’ in the pelvic region and the legs.
“X-rays do not provide a clear diagnostic tool for iliosacral arthropathy, but can offer valuable clues. Conventional diagnostic tests are of limited value. Based on these existing approaches, we have developed the PSIS (posterior superior iliac spine) distraction test. This screening test is simple to perform yet provides a reliable clinical assessment. It involves asking patients, who are standing or lying on their stomachs, about specific localized, central or lateral pressures that may trigger or exacerbate pain. The test is considered positive if typical pain is reproduced as a result. Compared to traditional provocation tests, the PSIS distraction test demonstrates superior accuracy of 94 per cent,” explains Prof. Dr Werner.
Our test.
Sacroiliac joint (SIJ) surgery involving stabilization and endoscopic ablation of pain fibers is a surgical procedure that may be considered to treat chronic pain in the sacroiliac joint region, particularly when conservative therapies have not been sufficiently effective.
Prof. Dr Werner explains the steps that need to be taken: “Before surgical intervention can be considered, the patient first receives at least two injections at intervals, during which a mixture of anti-inflammatory and analgesic agents is injected into the ligamentous apparatus and also directly into the joint space. The patient should experience a significant improvement as a result, thereby confirming that the treatment is targeting the correct area, so to speak. Patients must keep a pain diary using a pain scale of 0–10, and the injection must have brought about at least a 75% improvement, even if this was only felt for a short time. We then explain to the patient that complete relief from pain cannot be expected following surgery. The pain can only be reduced to the extent that was possible with the injection. In this procedure, the joint is stabilized to reduce excessive mobility and alleviate pain. If an implant has been surgically inserted in a stable manner – a procedure we perform here around 100 times a year – a second operation is carried out to perform endoscopic ablation of the pain fibers, in order to interrupt the pain signals and provide long-term relief. This is a further development of radiofrequency ablation (which is usually performed by the pain specialist or anesthesiologist using small needles to generate an electric current in the ligamentous apparatus, with the heat produced providing some relief to the pain fibers). “Using a camera (endoscopic method), we have a much more efficient and sustainable way of precisely vaporizing the fibers,” he adds,
Location of the pain fibers in the ligamentous apparatus outside the joint.
X-ray image showing the MUST SI implant.
“There are various approaches for implant placement. The type of implant is determined by the approach chosen. The posterior approach is used less frequently due to a higher complication rate. We usually opt for the lateral approach, as the risk of infection is lower here and the implants integrate stably. This approach also allows for the insertion of three implants, rather than just two, when the oblique posterior approach is chosen. Only a 2 cm incision (minimally invasive) is required. On the one hand, we use IFUSE implants, for which there are also Level 1 studies. These look like mini Toblerone bars, have a relatively large surface area and are also suitable for patients with osteoporosis. However, the triangular shape requires a triangular rasp to prepare the bone, which can occasionally lead to more severe bleeding. And as the implants are simply pushed through, patients have to walk with crutches for a few weeks after the procedure, which is sometimes difficult for older patients. On the other hand, there are implants that I helped to develop (MUST SI), which look like screws and allow compression of the joint. In this case, walking sticks are not needed for long afterward, and the patient can usually get up and walk straight after the procedure. These implants do not have a large surface area. We have therefore developed an additional coating, similar to that used for dental implants. They have the advantage of causing much less bleeding during insertion, as we only need to access the bone with a 4mm drill. Ultimately, however, both methods are very effective. The procedure itself—that is, the time taken for the incision and suturing—takes around 20 minutes. However, we spend just as much time ensuring the patient is positioned correctly. The patient can get up again the day after the operation.
Patient undergoing wound check-up 2 weeks after surgery with a lateral access scar from SI joint fusion
Intraoperative image during endoscopic denervation.
Following sacroiliac joint (SIJ) surgery involving stabilization and endoscopic denervation of the pain fibers, patients may have varying expectations regarding pain relief and the restoration of pain-free joint stability.
The primary expectation is that the surgery will help to relieve the pain caused by the sacroiliac joint. Many patients experience a significant improvement in their pain symptoms immediately after the procedure. As the joint heals and stabilizes, pain relief may improve further. Some patients are concerned that stabilization (fusion) of the SIJ will reduce mobility. It is important to understand that this is not the case with this procedure. In a normally functioning SIJ, stability is achieved through slight movement and tension in the ligamentous apparatus as soon as one stands or sits. The loss of mobility is therefore only theoretically present in situations where stability is not required. Patients report after stabilization that they can move more effortlessly due to the regained stability and pain relief. One can therefore expect overall mobility to improve. This functional improvement often contributes to an enhanced quality of life. “It is very important to explain things clearly to patients and make it clear that the pain will not disappear 100 per cent. Most patients are already happy after the first procedure. They can sit comfortably again, drive a car and sleep well. And that is a massive improvement in quality of life,” emphasises Prof. Dr Werner.
Following sacroiliac joint (SIJ) surgery, comprehensive rehabilitation and post-operative care are crucial to achieving optimal recovery and long-term results.
In an initial phase of 6 weeks following stabilization, early mobilization without overexertion is recommended. This is important to ensure that the implants heal smoothly without, for example, risking thrombosis or the formation of scar tissue. This can begin with assisted walking and gradually progress to more demanding activities. Physiotherapy plays a central role only in a second phase, to strengthen the muscles, improve mobility, promote coordination and restore balance. The management of post-operative pain is also of great importance in enabling successful rehabilitation. This may include the use of painkillers, anti-inflammatory medication or other techniques such as cold or heat therapy. A gradual resumption of activities is important to support recovery. It is crucial to ease back into normal activities of daily living, work or sport step by step.
“If a triangular implant is inserted, the patient should avoid excessive exercise for approximately eight weeks after the operation. Normal walking and strolling are fine, but physiotherapy should be avoided initially. After these eight weeks (Phase 2), most patients then benefit from building up strength in the gluteal muscles. Those who receive a screw implant are allowed to be more active. They can, for example, cycle or go for a light jog – but playing tennis, for instance, is not yet recommended. “We slow people down a bit here to ensure the implant heals securely,” says Prof. Dr Werner, describing the post-operative period, and adds: “It is very rare for an implant to break loose. This can only happen in the event of a serious fall or a fracture. It doesn’t just happen on its own.”
We have a shortcoming in our training regarding the SI joint.
“It’s a shame that the diagnosis and treatment of the SIJ isn’t part of our medical training. There are so many tricky aspects to this joint, such as clinical examination, the assessment of radiological features, the technique of infiltration, and even the surgical methods. In the USA, the problem has been increasingly recognized over the last ten years, particularly among spinal surgeons. In Europe, it will take a little longer and will probably require another generation,” states Prof. Dr. med. Werner, thus bringing our conversation to a close.
Thank you very much, Professor Clément M. L. Werner, for the insight into the sacroiliac joint, which is unknown to many!
Book recommendation:
Prof. Dr Werner – The Painful Sacroiliac Joint
ISBN 979-8375520353
80 pages
€29.95
Published on 4 February 2023.
Also available as an e-book on Amazon.
Book on the ISG.All photos ©Prof. Dr Clément Werner
