Thanks for your query I can understand your anxiety.Your husband definitely has developed cellulitis
an infection of soft tissue
.Pl get following blood test
1) Blood sugar-- fasting and post lunch to rule out diabetes
as cellulitis is very common in diabetic indisuals.2) Complete haemogram
3) Routine urine test
His wound needs to be cleaned and dressed properly everyday
Take some antibiotics and noninflammatory drugs and keep his leg elevated while sleeping.