Examining Bryce Harper's injury, recovery

Blame it on the headfirst slide, again.

The latest victim from just such an encounter with the bag this season is Bryce Harper, or, rather, Harper’s thumb. He is expected to undergo surgery Tuesday to repair the ulnar collateral ligament in his left thumb and could be sidelined until July, according to ESPN Insider Keith Law.

Harper made a dive toward third base Friday night to beat the throw on a triple, jamming his thumb into the bag in the process. Despite initial X-rays being reported as negative, the injury was not without serious consequences. The news is not a great surprise, as an X-ray would reveal injury only to the bone structure. While some thumb UCL injuries can result in damage to the bone near the ligament’s attachment, it is not the case universally (or, for various reasons, the damage may not be visible on initial films). Complete evaluation of these injuries typically requires additional imaging, such as MRI or CT scan, along with consultation with a hand specialist. Harper consulted with noted hand specialist Dr. Thomas Graham in Cleveland on Monday, after which the news of his impending surgery emerged.

The estimated timeline for Harper’s return falls within what can reasonably be expected following injuries such as this, depending on the degree of damage and the extent of the repair. When Los Angeles Angels outfielder Josh Hamilton tore his UCL earlier this month, also on a headfirst slide, I noted that two to three months is often the standard time frame issued when an athlete undergoes UCL surgery, with fluctuations dependent on the severity of injury and the specifics of the surgery. (Here are more details on the nature of a UCL injury and a hand surgeon’s perspective on recovery.)

With several key players sidelined already this season by thumb injuries resulting from headfirst slides -- the aforementioned Hamilton, who is not expected back for another month, Harper’s teammate Ryan Zimmerman, who suffered a fractured thumb diving toward the base on a pickoff play and is likely out until late May, and Los Angeles Dodgers outfielder Yasiel Puig, who missed only a few days earlier this month with a less severe injury -- the debate about the value of the headfirst slide rages onward.

There has been much discussion about whether there is any speed advantage for a headfirst slide, and the general consensus (based on studies comparing times for each) is that there is no significant difference between the two. But what about the injuries? Is the headfirst slide substantially more costly when it comes to severity of injury and days missed than an injury resulting from a feet-first slide?

To date, there has been no published study addressing these specific questions in Major League Baseball. There was a study published in the American Journal of Sports Medicine in 2000 that compared incidence and technique (head- versus feet-first) in sliding injuries among collegiate baseball and softball players. In this study, the injury rate in baseball players was higher for feet-first slides (7.31 per 1000 slides) than for headfirst slides (3.53 per 1000 slides). Additionally, the amount of participation time lost as a result of sliding injury was greater for feet-first slides than for headfirst slides, although only four injuries (between baseball and softball players combined) resulted in more than seven days of lost time. Of note, however, is the fact that headfirst slides were more likely to result in injuries to the head and upper extremities. It’s not surprising given the expected contact of the player’s hand with the bag (or even another player), but it supports the increased likelihood of thumb, hand and arm injuries when a player is injured during a headfirst slide.

It’s difficult to meaningfully extrapolate the information to the major league level. It does suggest that further examination of this topic among professional baseball players would be worthwhile, to establish whether the perception that the headfirst slide is inherently more dangerous is, indeed, anything more than a perception.