A thigh strain or quadriceps strain is a tear in one of the quadriceps muscles at the front of the thigh. It can range from a mild discomfort to a full blown tear of most of the muscle resulting in severe pain and inability to walk.
The breakage of the stitches starts within 2 weeks of the stitching but if you want the complete stitches to disappear then the process of hydrolysis or the enzymes in our body do that in a period of 60 days and therefore it approximately takes up to 2 months for the stitches to get dissolved.
Anywhere from 5-10 days. Be patient. It usually varies on types of suture but in general, if your stitches are dissolvable, they should start to break down within four weeks. When I had gum surgery, my surgeon advised me to continue taking salt water rinses, especially after eating, until those stitches got dissolve.