-osis. 1  1 suffix meaning a (specified) action, process, or result: homeosis, narcosis, zygosis. 2  2 suffix meaning increase in a pathological condition: calcicosis, psittacosis, varicosis. -osis. , pl. Combining form meaning a process, condition, or state, usually abnormal or diseased; production of an abnormal substance, increase of a normal substance, or parasitic infestation.
If non-surgical treatment fails to relieve the symptoms of accessory navicular syndrome, surgery may be appropriate. Surgery may involve removing the accessory bone, reshaping the area, and repairing the posterior tibial tendon to improve its function. This extra bone is not needed for normal foot function.
The most common surgery to treat Chiari malformation is posterior fossa decompression. It creates more space for the cerebellum and relieves pressure on the spinal cord. The surgery involves making an incision at the back of the head and removing a small portion of the bone at the bottom of the skull (craniectomy).