It seems there were X-Rays taken according to an article dated August 9, 1957:
<snip>
Roberts decided to have the body X-rayed, to determine if there was an old fracture of the left arm, like the Damman boy. Footprints also were taken for comparison.
Spelman, meanwhile, came up with a more detailed report on the body. "The cool weather makes it difficult to tell how long the boy was dead," he said, "but it was at least two or three days, and possibly as long as two or three weeks. I don't think the body was in the field that long, though."
According to laboratory tests the boy had not been sexually assaulted.
"As closely as we can tell, he is four to five years old, 40 1/2 inches tall, weighing 30 pounds. He has a full set of baby teeth, still has his tonsils, and has no deformities. No past bone breaks, and no vaccination scar. It would seem he was well cared for, because his fingernails and toenails are carefully clipped."
"His haircut seems crude," Spelman continued. "Trimmed high around the sides. Could have been given at home by an inexpert barber, or perhaps in an institution."
By then, the failure of parents or acquaintances to claim the body, after pictures and descriptions had appeared in the press, led police to believe the boy had either lived in an institution or been brought from some distance.
City Welfare Commissioner Randolph E. Wise offered to check on the whereabouts of all children in foster homes under his jurisdiction, while police canvassed orphanages and children's homes. A thorough check was made of all missing persons reports. But within several days all these efforts proved fruitless.
Police department technicians reported the blanket wrapping the boy was of cheap cotton flannel, patterned in a sort of "Indian print" of green, rust and white blocks, with faded colors. It apparently had been recently washed, then mended with poor-grade cotton thread on a sewing machine.
The blanket had been torn into halves. Its overall size would have been 64 by 76 inches. However, a section 31 by 26 inches had been torn from one half, leading police to think it might have borne some identifying mark.
Although the blanket was untraceable, investigators had better luck with the box. Marked "Furniture", it carried no firm name, but through serial numbers detectives learned the carton had once contained a baby's bassinet, shipped to a West Philadelphia department store in November, 1956.
The store reported the bassinet had probably been sold between December 3, 1956, and February 16, 1957. Roberts issued a public plea for the purchasers of all such bassinets during that period - there were believed to be about a dozen - to come forward and tell where they disposed of the cartons.
There were several other clues.
One was a blue corduroy "Ivy League" cap, size 7 1/8, found 30 feet from the body. The wearer had stuffed tissue paper in the sweatband. It had been manufactured in Philadelphia, but the trail ended there.
Two hundred feet from the body, along Verree Road, police searchers found a cache of clothing for a woman and child - but the smaller clothing was not the dead boy's size.
A story told by an informant who later contacted police seemed to cast some light on this clothing, but created a new mystery.
Two days before the body was found, said the man to Lieutenant William Lovejoy of the northeast detective division, he had been driving along Verree Road when he saw a middle-aged woman and a boy, 12 to 14, unloading something from the trunk of a car.
"I thought the car might have a flat tire, so I stopped and asked if I could help. They didn't say a word, and seemed to be standing so as to block my view of the license plate."
The scene which he described was almost exactly where the clothing had been found. The informant described the car and the woman and boy, but they were never found.
Meanwhile, the possibility that the dead boy was Steven Damman had been eliminated. Two Nassau County detectives came to Philadelphia to view the body and confer with local investigators. Footprints failed to compare; the body showed no left arm fracture. The visitors left convinced it was not Steven's.
</snip>
Complete article:
http://americasunknownchild.net/FrontPage.htm
So mito/DNA is now available and at some point he had a chest tube and a catheter (perhaps) as well as IV fluid or a transfusion through his legs because he was either too dehydrated to present with a good vein or he was damaged like in an accident. Were there ever XRAYS done to see if he had broken bones? Arms and hands spring to mind...