“The valgus force relieves the medial compartment”

Prof. Olivier Barbier’s approach is characterized by biomechanical and interdisciplinary considerations. In this interview, the orthopedic surgeon from Toulon explains how the challenge of osteoarthritis of the knee is tackled in France.

life: What are the major pain triggers in cases of osteoarthritis of the knee?

Prof. Barbier: One of the decisive factors is an excessive strain exerted on the knee joint based on axial misalignment of the lower extremity. The medial knee compartment is particularly susceptible and it is affected in 90 percent of all cases. Varus knee malalignment contributes to increased texternal knee adduction moment and thus results in increased medial compartment loading. In fact, in varus knees the mechanical axis runs medially to the center of the knee joint. This causes the transition of the majority of the load onto the medial compartment already during standing. In ten percent of patients the lateral compartment is affected. The anatomy, kinematics and loading during movement differ considerably between medial and lateral compartments of the knee. This explains mainly the relative protection of the lateral compartment compared with the medial compartment in the development of osteoarthritis.

What is your treatment approach?

Prof. Barbier: I use surgical as well as non-surgical methods. Conservative methods have priority and are always indicated in first intention. They also include pharmacological treatment, such as the use of paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), or intra-articular injections to reduce pain. Oral NSAIDs, such as ibuprofen, can be used to alleviate pain but only intermittently for a short duration and in conjunction with proton pump inhibitors. They pose a real risk of adverse gastrointestinal, cardiovascular and renal reactions. Furthermore, the long-term use of analgesics can be counterproductive. Pain is a crucial indicator of injury. Analgesics hide the pain without treating the underlying condition. Intra-articular injections of corticosteroids is effective in the short term in case of the presence of effusion and intra-articular hyaluronic acid (IAHA) is still recommended. Intra-articular platelet-rich plasma (PRP) injections are often recommended in France and seem promising. However, there is quite a lot of heterogeneity and a lack of standardization for the available products. Surgical procedures are a last resort for end-stage knee osteoarthritis.

How can supports and braces help during conservative treatment?

Prof. Barbier: Supports and braces provide the joint with general protection, reduce swelling and alleviate pain. Especially braces that influence biomechanics are an important primary non-surgical option. The GenuTrain OA, for example, is a valgus brace that provides medial relief and offers an option for treating pain in the medial compartment due to osteoarthritis in case of a Genu varum. The brace’s mode of action aims to reduce the external knee adduction moment. It exerts external valgus force on the knee, causing the load on the medial compartment to reduce.¹

Are there other indications for the GenuTrain OA?

Prof. Barbier: The effect of valgus braces when alleviating pain in the medial compartment is comparable to a high tibial osteotomy. I therefore also use the GenuTrain OA in pre-operative care before performing an osteotomy or a unicompartmental knee replacement as a diagnostic test. If the test is positive, it’s a promising criterion for the effectiveness of these procedures. I also use the GenuTrain OA after meniscus surgery to protect the suture during the first month.

In your opinion, what are the advantages of the GenuTrain OA when treating osteoarthritis of the knee?

Prof. Barbier: All features must serve one purpose: compliance. Patients must want to wear their brace. Osteoarthritis of the knee is based on a complex pathological condition. To do it justice, we have to think in a multi-modal way. This includes different disciplines to inform patient education. Lifestyle, diet and body weight are important factors each patient can influence. If the patient notices that a brace is helping, this will fulfill a basic prerequisite that is needed for a high level of compliance. The GenuTrain OA is characterized by flexibility, thanks to the elastic knitted fabric, and reduced pressure at the back of the knee. The brace has a low profile and neither obstructs during walking nor collides with the contralateral knee.

Which arguments do you use to convince patients during your consultation?

Prof. Barbier: It’s the relieving force vector, of course, that is the pivotal characteristic of the GenuTrain OA. The tension created by the relief and stabilization system around the knee can be individually adjusted using a dial, allowing the patient to match the relieving force to their requirements. The low weight and secure positioning on the knee make sporting activities easier again. Once this initial step has been made, nothing will stand in the way of a great quality of life. GenuTrain OA is easy to use, easy to install and easy to wear.

1 See, for example, the study conducted by Kutzner, I., et al. about pressure relief braces. The effect of valgus braces on medial compartment load of the knee joint – in vivo load measurements in three subjects. Journal of Biomechanics 44 (2011): 1354–1360.

Images: Barbier, Udo Schönewald, shutterstock.com/wk1003mike/Jarva Jar/decade3d – anatomy online