Kilian Jornet Is Missing UTMB for Surgery on the Knee He First Broke in 2006

Kilian Jornet said Thursday that he will have surgery on his knee and will not run UTMB, the 174-kilometer (108-mile) race around Mont Blanc that starts in Chamonix, in the French Alps, on Aug. 28. He has won it four times. He named no procedure, no date and no timeline.

The Spaniard had been managing the knee without an operation, well enough to keep training. He announced the change on Instagram, in a post L’Équipe carried on Thursday afternoon. “After several months dealing with a knee injury, we have decided, together with my medical team, that surgery is the best next step,” he wrote. “However, after a long effort a few days ago, I realised that the issue was still there, which means we need to find a more permanent solution.”

His own account has been public since June 2, when he published his MRI report on his Substack: “Horizontal rupture in the anterior horn of the lateral meniscus … Cartilage damage centrally on the patella with adjacent bone marrow edema.” The patella is the kneecap, the meniscus is the cartilage that cushions the joint, and bone marrow edema is fluid inside the bone beside the damage. He named the knee himself in that post, writing that he went into Western States “managing pain in my left knee, doing physiotherapy at home.” The pain had been with him for about three years, he wrote, probably beginning with a first meniscus tear, and it sharpens on fast, flat running and eases when his training turns uphill. iRunFar reported in its Aug. 17 preview that after Zegama-Aizkorri in May he had acknowledged an injury bad enough that going down stairs hurt.

The kneecap broke in 2006, when he was still at school, carrying an armload of books home, and jumped from one street down to the next onto cobbles. Surgeons used a cerclage, a wire loop that holds a broken bone together while it knits, and by his account the doctor doubted he would return to top-level competition. He wrote in June that “every kilometer my knee allows me to run hard is a gift.”

The same post carries his explanation for why the breakdowns keep coming. He wrote that “the system where I notice the biggest decline with age is the neuromuscular system,” and that “because of that, mechanical injuries and muscular problems have become more frequent.”

He set out three races for the season in February: Western States on June 27, Sierre-Zinal, a 31-kilometer mountain race in Switzerland, on Aug. 8, and UTMB. He picked them, he said in comments carried by RUN247, because “what excites me isn’t discovery or exploration … It’s the competition.” He started two races this year and finished one. At Western States he fell back from about mile 25 and stopped at Dusty Corners, mile 38 (about 61 kilometers). The other start was Zegama-Aizkorri on May 17, a mountain marathon in Spain’s Basque Country and not one of the three, where he finished 43rd in a race he has won 11 times. He skipped Sierre-Zinal to protect the UTMB build.

His UTMB Index rating of 948 was second only to Jim Walmsley’s 967 in a men’s field the organizer called one of the strongest in its history. The Index is the organizer’s own rating, built from a runner’s best scores over 36 months. He is the third confirmed absence from that field, after Katie Schide and the defending champion, Tom Evans. iRunFar’s preview named Ben Dhiman the favorite and listed Walmsley and Jonathan Albon as injury doubts.

UTMB will now go a fourth consecutive edition without him. Bone edema in his right hip cost him 2023, and he did not race it in 2024 or 2025. The last time he started, in 2022, he won in 19:49:30, the first finish under 20 hours in the race’s history. “There are still many unknowns about the next steps,” he wrote, “but I will share more when I know more.”