An indisputable legend in the world of tennis, Rafael Nadal nevertheless suffers from a rare pathology affecting a bone in the foot, which can cause chronic pain. This disease, Müller-Weiss syndrome, increasingly handicaps the Spanish champion. Also called osteonecrosis of the navicular bone or tarsal scaphoid, this condition is “chronic and incurable”, he said in early May. The tennis player has suffered from it since he was 18 years old.

This syndrome affects the navicular bone, located on the back of the foot, between the talus and the cuneiform bones. “This bone is subject to significant stress and, for reasons that we do not know, loses its vascularization and necroses”, explains to Agence France-Presse Denis Mainard, president of the French Association of foot surgery and chief from the orthopedic surgery department of the Nancy hospital. In the most serious cases and “in subjects who put a lot of strain on their feet, the bone will disintegrate, flatten, it can fragment and, in the end, this can evolve into osteoarthritis with a shortening of the plantar arch. “, he specifies.

Müller-Weiss syndrome can affect only one foot, but more often both. Rafael Nadal suffers from only one foot, the left. This pathology more often affects women, and people between 40 and 60 years old. Professor Mainard does not know the file of the Spanish player. But he raises the “intellectual hypothesis” that he could have been affected, as a child, by Köhler-Mouchet disease, a rare pathology of growth of the navicular bone affecting children under 10, especially athletic boys, and which can leave scars.

Müller-Weiss syndrome has five stages: the first is without symptoms, the last is osteoarthritis. The causes of this disease remain unknown. “In the two authors who initially described it, Müller thought it rather of traumatic origin, Weiss rather vascular. For the moment, we consider that the origin is rather vascular”, notes Prof. Mainard.

Certain factors can increase its risk of appearance such as being overweight, flat feet, a stress fracture… This disease is often difficult to diagnose initially, because it develops silently in the early stages. The pain usually appears later. In addition to rest, orthopedic insoles can reduce mechanical stress. Faced with pain, anti-inflammatory treatments and infiltrations complete the therapeutic panoply.

“I live with a ton of anti-inflammatories on a daily basis to give me a chance to train. […] If I don’t take it, I limp,” says Rafael Nadal. And “my problem for quite some time now is that there are a lot of days where I live with too much pain”.

For patients whose pain is no longer relieved and who can no longer walk, surgery may be prescribed. It blocks both joints involving the navicular bone. “In cases where the navicular bone has broken down, a bone graft is also needed to restore the length of the internal arch of the foot,” says Prof. Mainard. “Practicing sport at a high level after such an operation seems difficult,” he judges.