ZERO1 Provides Post-Surgery Update On Yoshikazu Yokoyama, Reveals He Was Diagnosed With Cervical Ossification

Details of the diagnosis.

The last time that 15-year veteran Yoshikazu Yokoyama wrestled was on August 31st, 2025. He was in action for the Pro Wrestling ZERO1 promotion.

ZERO1 pushed out an update on Yokoyama and noted that he underwent a successful surgery. They had kept his personal matters private, but after his successful surgery and his recovery seeming favorable, they shared that he was diagnosed with ossification of the posterior longitudinal ligament.

Yokoyama is rehabbing and is aiming for a return to in-ring action.

【ご報告】
休業中の横山佳和選手につきまして、現在の状況をご報告いたします。

これまでは治療に専念するため公表を控えておりましたが、医師による検査の結果、「頸椎後縦靭帯骨化症（指定難病）」との診断を受けました。… pic.twitter.com/BFvmcI2Fn0

— プロレスリングZERO1（ゼロワン） (@ZERO1_Wrestling) December 2, 2025

Columbia University’s neurosurgery department has the following on its site about ossification of the posterior longitudinal ligament:

Ossification: process of changing into a bone or bone-like substance
Posterior: anatomical term meaning “further back in position”
Longitudinal: anatomical term that means “traveling long-ways”
Ligament: soft tissue that connects and supports the bones of joints

Ossification of the posterior longitudinal ligament (OPLL) is a condition in which a flexible structure known as the posterior longitudinal ligament becomes thicker and less flexible.

The posterior longitudinal ligament connects and stabilizes the bones of the spinal column. It runs almost the entire length of the spine, from the 2nd vertebra in the cervical spine (neck) all the way down to the sacrum (end of the spine). The ligament is adjacent to the spinal cord.

OPLL most often occurs at the cervical spine (spine in the neck).

Yokoyama has been wrestling for Pro Wrestling ZERO1 since 2010. He’s held one title in the promotion, and that was in 2015 when he won the now-inactive United National Heavyweight Championship.