Monthly Archives: July 2016

Limits on Innings

To prevent serious arm injuries, young baseball pitchers should pitch no more than 100 innings a year, researchers said.

In a 10-year prospective study, boys who pitched more than 100 innings were almost four times more likely to undergo elbow or shoulder surgery or to retire because of injury, according to Dr. Glenn Fleisig, of the American Sports Medicine Institute in Birmingham, Ala., and colleagues.

The cumulative rate of serious injury was 14 percent in those who exceeded that number and 4 percent in those who did not, the researchers reported in the February issue of the American Journal of Sports Medicine.

“On the basis of these findings and review of the literature, we recommend that pitchers in high school and younger pitch no more than 100 innings in competition in any calendar year,” Fleisig and his colleagues wrote.

“Young pitchers who have not developed should be limited to even less, and no pitcher should continue to pitch when fatigued.”

In recent years, researchers have detected an increase in the numbers of younger pitchers who require shoulder and elbow surgery, including ulnar collateral ligament reconstruction, or Tommy John surgery.

Many doctors believe that the trend is related to the growth of year-round baseball leagues and showcases for professional scouts, which reduces the amount of downtime pitchers would normally have in the off-season.

A 1999 study linked the number of pitches thrown to elbow and shoulder pain — assumed to be a predictor of future injury. That and similar studies led youth baseball organizations, including Little League Baseball, to replace innings limits with pitch counts.

But no studies had established a relationship between throwing volume and injury risk.

To explore the risk factors for serious arm injuries — those requiring surgery or those resulting in retirement — Fleisig and his colleagues followed 481 male pitchers ages 9 to 14 for 10 years using annual telephone interviews; about two were still pitching in the final year of the study.

The researchers focused on total innings pitched in the previous year rather than pitch counts because most youth players and their families do not keep track of the numbers of balls thrown.

During the study, three of the boys had elbow surgery, seven had shoulder surgery, and 14 retired because of a throwing injury, resulting in a 10-year rate of serious injury of 5 percent.

The average age at the time of surgery was 17, and two boys underwent surgery before they turned 13.

The only significant risk factor for serious injury was pitching more than 100 innings in a calendar year.

There was a trend toward a greater likelihood of serious injury in boys who played both pitcher and catcher during the study period (11 percent versus 4 percent), but it fell short of statistical significance because of the small sample size, according to Fleisig and his colleagues.

“A baseball player may play multiple positions, but we discourage an individual from playing both pitcher and catcher,” they wrote.

Although it has long been believed that starting to throw curve balls at a young age can cause harm, there was no significant difference in the rate of serious injury between those who threw the pitch before they turned 13 and those who started throwing it later (7 percent versus 4 percent).

Long Term Death Risk

The risk of death after head injury remained significantly increased for as long as 13 years, irrespective of the severity of the injury, results of a case-control study showed.

Overall, patients with a history of head injury had more than a twofold greater risk of death than did two control groups of individuals without head injury.

Among young adults, the risk disparity ballooned to more than a fivefold difference, Scottish investigators reported online in the Journal of Neurology, Neurosurgery and Psychiatry.

“More than 40% of young people and adults admitted to hospital in Glasgow after a head injury were dead 13 years later,” Dr. Thomas M. McMillan, of the University of Glasgow, and coauthors wrote in the discussion of their findings. “This stark finding is not explained by age, gender, or deprivation characteristics.”

“As might be expected following an injury, the highest rate of death occurred in the first year after head injury,” they continued. “However, risk of death remained high for at least a further 12 years when, for example, death was 2.8 times more likely after head injury than for community controls.”

Previous studies of mortality after head injury have focused primarily on early death, either during hospitalization or in the first year after the injury. Whether the excess mortality risk persists over time has remained unclear, the authors noted.

Few studies have compared mortality after head injury with expected mortality in the community. To provide that missing context, McMillan and coauthors conducted a case-control study involving 757 patients who incurred head injuries of varying severity from February 1995 to February 1996 and were admitted to a Glasgow-area hospital.

For comparison, the investigators assembled two control groups, both matched with the cases for age, sex, and socioeconomic status and one matched for duration of hospitalization after injury not involving the head.

One control group was comprised of persons hospitalized for other injured and other comparison group included healthy non-hospitalized adults.

The cases comprised 602 men and 155 women who had a mean age of 43, and almost 70 percent were in the lowest socioeconomic quintile.

At the end of follow-up, 305 of the head-injured patients had died, compared with 215 of the hospitalized control group, and 135 of healthy, non-hospitalized adults.

Mortality after one year remained significantly higher in the head-injury group—34 percent versus 24 percent among the hospitalized comparison group and 16 percent for the healthy non-hospitalized adults.

Overall, the head-injury group had a death rate of 30.99/1,000/ year versus 13.72/1,000/year in the community controls and 21.85/1,000/year in the hospitalized-other injury control group.