I'm a huge San Francisco Giants fan so when our best hitter landed on the DL with a fracture in his left hand, at first all I could think about was our 2012 prospects. After my personal pity party, I then got concerned for the Panda's hand. Yeesh. Fractured hamate. That's not good, but we have some evidence that he will recover his bat because he did the same darn thing last year with his right hand. At least he's got experience. Now the press reported that surgeons "removed the fractured hamate bone" and he's on the road to recovery and we hope to have him back in a few weeks. But wait a minute. Remove the hamate? What?! When we evolve a bone in our hand, we need it for something!
The hamate is in the middle of the hand and is shaped a bit like a comma, with a tail or a hook.
If you put your right hand up in the air in front of you, palm down and fingers pointing away, you are replicating this picture. Visualize removing the row of bones that are closest to your wrist (scaphoid, lunate, triquetrum) and looking head-on at the second row of bones (trapezium, trapezoid, capitate and hamate).
The hamate has a little "hook" on it that projects into the palm of the hand. If you're holding a bat and hitting the ball as hard as the Panda, that hook is going to absorb a lot of the energy from striking the ball. It's not surprising that a big hitter like Panda could break that little teeny hook right off.
When they say surgeons "removed" Panda's hamate they likely mean that they removed only the hook portion of the hamate. Thank God for that. But still, the body only evolves bony projections like that hook for a good reason. So what is going to be affected by removal of the hamate hook?
The hook shape acts as a guide, to keep the tendons and muscles corraled between it and the trapezium in the area known as the carpal tunnel. These bony walls are backed-up by a strip of fascia kind of like a support crew (known as the flexor retinaculum or the transverse carpal ligament) and is shown as the gray "ceiling" of the carpal tunnel in the above picture. This strip of fascia is going to have to go it alone on the pinky side of Panda's hand. Luckily this strip is also anchored by the pisiform.
The hamate hook is also the attachment point for the flexor carpi ulnaris, which is a muscle that helps flex the wrist and tilt the hand relative to the wrist. In other words, it helps your hand and wrist move or be stable against resistance. Surgeons probably relocated this muscle's tendon so it can still participate.
Guha and Marynissen write,
"Fractures diagnosed within three months can be treated conservatively with immobilisation involving the fourth and fifth fingers. Late or recurrent cases are probably better treated with excision of the hook of the hamate to avoid possible complications such as rupture of the flexor tendons."
So although Panda was evaluated the day after his injury, I imagine they decided to remove the hook surgically because that would allow the fastest recovery and avert a possible catastrophe of rupture of flexor tendons. Those are the tendons that allow him to grasp a bat. Rupturing them would be a total catastrophe.
Considering his was the hottest bat until Melky Cabrera came along, I'm looking forward to the Panda's flexor tendons going up against the Milkman's flexor tendons. Play ball!
