I've been struggling with this for 15 years. Outward rotation of my right foot causes the most pain, however it is now pretty constant, even while I sleep. Physical therapy and anti-inflammatories have not helped. I had to quit my job until I can find relief. Both physicians are on the faculty of the University of Missouri-Columbia School of Medicine.
Avulsion means a tearing away or separation.
This means that the bone is not only cracked or broken, but has also separated. The recovery period depends on the severity of the fracture, the patient's general health, and whether he or she receives proper care during the healing process. Recovery times for anything of this nature are individual. Your son's doctor could probably give you an estimate if an X-ray shows good alignment of the bone fragments and progressive healing is demonstrated during the first few weeks. We might guess six to 10 weeks.