This article is part of our Injury Analysis series.
The Colts running back will miss time after suffering a broken hand in the team's win over the Jaguars. The injury required surgery and Mack has already been ruled out for Week 12.
The wrist and the hand are made up of numerous bones of varying sizes and shapes. At the end of the forearm sit the eight carpal bones of the wrist. These tiny bones form the true wrist as well as the carpal tunnel and are fortified by an extensive network of ligaments. If an injury occurs here it is classified as a wrist or hand sprain.
After the carpals, sit the metacarpals of the hand. The five metacarpals bridge the area between the phalanges (fingers) and the wrist, and serve as an anchor site for muscle attachment. The distal ends of the metacarpals form the knuckles of the hand. The second and third metacarpals are anchored to the carpal bones, making them generally immobile. Conversely, the fourth and fifth metacarpals are mobile to allow for a higher degree of motion at the wrist and pinkie.
Specifics are limited on the exact bone involved, but Mack's injury has been reported as a metacarpal fracture. Given that surgery was necessary, it is likely the bone broken became displaced or misaligned. Surgery will involve the placement of surgical hardware, potentially a plate or screws, to stabilize the fragmented pieces and assist in healing.
Metacarpal fractures aren't uncommon in the NFL, especially for running backs. Fortunately, the success rate