The shoulder blade (scapula) is rarely broken (broken bones are also called fractures). Shoulder blades breaks comprise less than 1% of all fractures.
Scapular fractures occur more often in young men aged 25-45 years because of the activities and trauma they encounter. These occur with athletic activities, motor vehicle accidents, and other forms of blunt trauma.
http://www.emedicinehealth.com/broken_shoulder_blade/article_em.htm
One of the posters on TMZ said that it won’t heal. Don’t know anything about that.
Essentially, the broken scapula shows he was curled up on the ground protecting his head while the beat his scapula with their nightsticks.... Or something like that.