Thanks for posting your query.
After reading your whole query, there may be possibilities of nervous system damage and impaired blood supply.
Has he undergone x ray
of the affected limb? What was its reports?
As your friend is not feeling sensation, there may be possibility of nervous system involvement.
Swelling with damaged skin layer indicates involvement of blood supply.
There may be possibility of simultaneous involvement of both system.
There may be following other possibilities: Cellulitis
in affected limb, underlying crush injury
You should consult with surgeon and orthopedic surgeon and go following investigations: complete blood count
, color doppler study of affected limb, nerve
conduction studies of affected limb.
Dr. Mayank Bhargava