Answer
Egil the Viking had Paget's disease which is a chronic condition of the bone characterized by disorder of the normal bone's remodeling process. Paget's disease results in irregular thickening of bone tissue and often affects the skull and spine, causing pain and deformity. Paget's disease affects older skeletal bones of adults.
Work Step by Step
This skull from a Pagent's disease patient just shows the thinking in the skull and the this also answers the extensive remodeling of the fingers and his spinal cord issues.