The unknown injury to Ben's arm in the last episode of Lost led me down this path. I believe that his wound relates to time travel, and that side characters like Dr. Marvin Candle have lost limbs and various body parts attempting to do the same thing over the years...either leaving the island or attempting to get there.
Whether or not any or all of these characters were injured during 'the incident' or the violent journey of time travel (or are connected to Ben, Widmore or Dharma) remains to be seen...
We never met him, but Locke referred to double amputee Croucher as an example of someone with disabilities who conquered a physical challenge (he climbed Everest; Locke wanted to go on the Australian walkabout even though he was in a wheelchair).
Sawyer's former con partner was missing the top part of a finger on his left hand.
Another character that we never met. Danielle Rousseau briefly mentioned that he lost his arm in the dark territory near the Black Rock ship.
Ray called the Marshall on Kate (for the reward money) shortly after she showed up at his farm. She crashed his truck to avoid the Marshall, and discovered that he had one prosthetic arm when she pulled him out of the wreckage.
Martha's deceased husband Sam was in the military with Leonard Simms, the man who mumbled "the numbers" at Hurley's mental institution. Leonard told Hurley that he first heard about those cursed numbers from Sam, so Hurley went to Australia to find Sam Toomey (and then left on Flight 815). While there, Hurley learned that Sam had passed away, and saw that Martha had one prosthetic leg; she told him that she lost it in a car accident.
The infamous statue of an amputated leg with four toes was spotted by Sayid, Jin and Sun on the sailboat as they were awaiting a signal from Jack, Kate and Sawyer. Yeah, that never happened.
Candle appeared with a prosthetic arm in the first Dharma Orientation film, in the original Swan hatch. The same actor has since appeared in other Orientation films using different names (Dr. Mark Wickmund, Dr. Edgar Halliwax) and with the use of both arms at times. Sidenote: all of his pseudonyms share a common theme (candle, wick, wax).
Eko found a glass eye placed inside a bible, in the Arrow station where the Tail Section folks hung out for a while. Perhaps it belonged to Mikhail...
Dead or not, Mikhail sports an eye patch.
..am I missing anything?