Reddening/swelling
The described signs of wear and tear and the subsequent inflammation in the joint lead to a painful restriction of movement in the metatarsophalangeal joint of the big toe. In the metatarsophalangeal joint of the big toe, in addition to minimal abduction, stretching (dorsal extension) and flexion (plantar flexion) are possible. In hallux rigidus, the dorsal extension in particular is significantly limited.
The degree to which the movement of the affected joint is restricted compared to the opposite side also determines important stages of hallux rigidus. As a result of the painfulness, movements in the affected joint are consequently avoided. In addition, the ossification narrows the joint space so that the joint becomes increasingly stiff.
Classification
In hallux rigidus, as in all types of arthritis, 4 different stages can be distinguished. A grade 1 arthrosis is considered to be present when the movement restriction of the affected joint is at most 50% compared to the other foot and the pain is not constant and only present in relation to the load. Osteoarthritis grade 2 is characterized by a movement restriction of 50 to 75%, the pain is more pronounced, and in some cases there is already a feeling of stiffness in the joint.
Osteoarthritis grade 3 describes a movement restriction of 75 to 100%. Especially the upward movement of the joint can usually no longer be performed. Pain here is permanent and may worsen under stress.
Arthrosis grade 4 can only be distinguished from grade 3 by the fact that no joint space can be found in the X-ray image, whereas it is only severely narrowed in grade 3. Hallux rigidus must not be confused with hallux valgus, which also causes pain in the metatarsophalangeal joint of the big toe, but has other causes.