An Occupational Therapist Explains Mechanism, Rehab of Victor Caratini’s Hamate Fracture

Victor Caratini broke his left hamate bone Thursday night on the first swing of an at-bat in which he ended up doubling to the gap. He said afterwards that he felt something crack on the swing, so the Cubs removed him from the game and he’ll have surgery Monday to correct the issue.

Hamate fractures are among the least common fractures in everyday life but tend to happen to baseball players with regularity. In my practice as an occupational therapist, I often see carpal fractures as a result of “FOOSH” (falling onto an outstretched hand) injuries. So while a hamate hook fracture like Caratini’s is a bit out of my everyday experience, I hope I can help simplify some of the mechanisms associated with his injury and what his rehabilitation might look like.

Mechanism

Unlike other carpal fractures, hamate fractures almost always occur at the “hook” of the bone as opposed to the “body.” You can see that hook in the images above, it’s the protrusion that doesn’t exist in the neighboring carpal bones. Just looking at the images gives a pretty good clue as to how a fracture like Caratini’s occurred. Swinging the bat or making contact with the ball can put a lot of pressure on that hook and, unfortunately for Caratini, that pressure exceeded the bone’s durability on Thursday night.

Caratini’s wrist has likely been immobilized by a custom made splint since Friday. The splint is designed to prevent him from causing further damage to the bone, aggravating the precariously close ulnar nerve, or increasing pain prior to surgery.

It’s worth noting that the way this injury is dealt with in athletes is different than how a surgeon might approach an everyday patient. Were I to fracture my hamate, the surgeon would be more likely to use screws and nails to fixate the hamate hook back to the body of the bone or even to skip surgery entirely and just immobilize the joint to provide time for healing. This results in a longer recovery but keeps the original structure of the bone intact.

Athletes are a different story. Because there’s motivation both to get back quickly and to reduce the possibility of instability associated with fixations using screws and nails, surgeons most often simply remove the hook of the hamate since it’s not inherently functional. Caratini’s left hamate will likely end up as a hookless carpal bone like all of the other carpal bones. This will remove any stability issues associated with attempting to fixate the hook back to the body and eliminate the possibility of re-fracturing the hook.

Recovery and rehabilitation

Assuming Caratini does simply have the hook of his hamate removed instead of a fixation, his post-operative rehabilitation should be pretty straightforward. The general progression for any orthopedic surgery rehabilitation is generally going to be as follows: 1) active range of motion (movement by the patient); 2) passive range of motion (manipulation by the therapist); and 3) strengthening. Assuming the procedure goes off without a hitch, Caratini will likely jump to strengthening within his first session or two of rehabilitation.

In this case, that means will mean working on grip strength. A weakened grip is one of the biggest potential perils associated with any carpal injury. The reason for Giancarlo Stanton’s long absence from a similar hamate injury in 2015 was an inability to get that strength back to baseline. Stanton’s experience is way out of the norm, but someone has to live at the extreme end of the bell curve.

Caratini’s work with the Cubs trainers will undoubtedly consist of swinging the bat early on to try to get used to it again, but his hand therapy at the surgeon’s office will be hyper focused on developing his grip strength and won’t bear any resemblance to baseball activities. Think more along the lines of squeezing balls or using a highly resistive gripper to manipulate pegs on a board rather than any skills associated with his job.

Caratini will be able to work with some fancier tools at the surgeon’s office, but there are only so many ways you can work on grip strength. At home, he’ll be assigned an exercise program that will consist of squeezing resistive therapy putty, balls, or similar objects to continue improving his strength. Caratini won’t differ from other patients in that his willingness to adhere to his home exercise program will have at least as big an impact on his recovery as how hard he works in the presence of his therapist.

His grip strength will be measured at the beginning and end of each session to assess progress. As a rule of thumb, Caratini will be ready to go when his left hand’s grip strength is at about 90% of his dominant right hand.

Game impact

There is a general consensus that players return to baseline performance at the plate following hamate hook removal. Weakened grip strength would have a significant impact on a hitter’s ability to drive the ball, but Caratini shouldn’t be cleared to play until his grip strength is within the normal limits described above. So it’s a safe bet that by the time he returns he’ll be at his baseline.

Defense, and defense at catcher in particular, is a different story and was my initial reason for wanting to explore this a bit further.

When I first learned of Caratini’s injury, my initial concern was that his recovery might be lengthened by his responsibilities as a catcher. That surgical site is inherently delicate and my fear was that catching 90+ mph pitches for nine innings would be the kind of repetitive trauma that might make a surgeon shy away from the timetable we’ve seen with other players.

However, my fears appear to be largely unfounded based on the past history of catchers having undergone hamate fixations on their catching hand. Austin Hedges and Max Stassi are recent examples who returned on schedule from hamate fractures, and studies validating the effectiveness of hamate repairs have included catchers without additional qualification.

Putting it all together

There’s a lot to be encouraged about here. I began this piece as kind of a test case into my personal hypothesis that catchers might be more significantly impacted by hamate fractures and postoperative complications than other players and I’m happy to report that that hypothesis doesn’t have much weight behind it. The average recovery time is 4-6 weeks and while there will always be outliers, there is no reason to think that it’s an unrealistic timeline for Caratini.

If you want to live a day in the life of Caratini over the next few weeks, just grab a ball and start squeezing.

Images generated using 3D4Medical’s Essential Anatomy 5.