The Miami Marlins have to be disappointed with their season, and part of that disappointment has to involve Giancarlo Stanton and his extended recovery from a hamate bone fracture suffered in late June. The initial word on Stanton's injury is that the hamate bone fracture could take six to eight weeks for recovery given that the planned intervention was surgical excision of the hamate bone. This is now standard of care in patients with this type of injury, especially in patients who are athletes. This sort of injury is common in gripping bat-like objects like in golf or baseball.
Stanton had the bone excised on June 28 in a surgery that went smoothly with no complications. However, his recovery has taken longer than expected, and he may not return in the 2015 season.
There is no strong particular indication as to what the problem is with Stanton. He did not go through his live game rehab process because the hand "wasn't feeling right," which could mean a variety of problems. The biggest concern is the healing process with regards to the injury is surrounding tissue damage due to the fracture. Tendon or sheath injury to the surrounding connections can cause problems in recovery. That surrounding damage can caused extended periods of pain and sensitivity in that area, which could be the cause for the delay in Stanton's recovery and his continued symptoms.
The more concerning problem is if his grip is not "feeling right" because of weakness rather than pain. Pain will require medication and perhaps a slower approach, but weakness in the finger without necessarily having pain may be more indicative of an ulnar nerve injury. The ulnar nerve that supplies strength and sensation to parts of the ring and pinky finger runs through the ulnar canal, and the hamate bone has several attachments in and around those nerves. Surgical removal of the bone has the theoretical risk of damaging the ulnar nerve, which makes gripping with the pinky finger much more difficult. A weakened grip can cause some serious issues for a player who makes his name on power.
The good news is that the precedent for such an injury is not large. Several retrospective chart reviews have been done on surgical removal of the hamate and subsequent recovery (see results here and here), and most of them mention positive outcomes within three months of surgery. Stanton had immediate recognition of injury and prompt intervention, so it is likely he will recover just fine. Furthermore, in a limited study of recent players who have suffered this injury, Beyond the Box Score's Stuart Wallace found that players recover their power well after the injury.
Overall, it appears that with time, player's [sic] who succumb to a hamate injury will find themselves back to previous power numbers upon their return to play, though it will probably take roughly a full season of at bats to do so. Of course a number of other factors could predispose a player to not bounce back quite as quickly or as robustly—age of injury, previous injury history, and even the time it took for correct diagnosis and treatment approach all play potential roles—but compared to other upper extremity injuries, the outlook for a full return to health and hitting power with the hamate fracture is generally promising.
The most likely result is that Stanton will recover well from the injury, even if it requires that he stay out for the rest of the season to build up strength. The issue of finding reps to practice, especially in game-style situations with more realistic pitching, will continue to be difficult. Minor league levels are done with their seasons at this time, and Stanton will not be able to play on those rosters to get the practice in. But at this time, he may not even be ready to face 90 mph fastballs and take honest hacks at them anyway.
However, while we continue to see these reports, we do have to at least remain cautious about his situation. Stanton needs to continue to build up strength in that hand, as that strength is critical for the Marlins. The likelihood of long term consequences is low, but it is a specter while Stanton continues to rehab his longest-lasting injury yet.