One broken ankle isn’t going to raise rates.
The increase seems to be with chronic illness and repeated hospitalizations.
Medicare supplements rate increases apply equally to all insured members. This is regardless of their health conditions experienced in the last year. An insurance carrier cannot exempt you from rate increases because you are healthy. Likewise, they cannot single you out for an increase just because you are sick.
Premiums might be higher, though, for a person who does not enroll during the standard enrollment period and has to undergo underwriting.