Joe was 10 at the time.
This is the side of the leg that wasn't hit. The big scar at the bottom is where his leg bent so much before snapping, that the skin at this point stretched to the point where it split open. This was the gaping great hole in Joe's leg you'll see in the post above. The 2nd scar mid way up his lower leg is where the bone once it had snapped came through his skin was scraped along the road. The two small scars up near his knee are where the metal pins where put in and removed. The bulge on his shin may be due to the additional calcium growing where the bone grew back.
Remarkably this is the impact side, the scar is barley visible in this light, but it's there at the base of his calf muscle. Again the small scar at the top is where the pins came in and were taken out.