How long does a tendon surgery take?

Sometimes weeks, sometimes never

Tendon damage does not heal as quickly or as thoroughly as muscle damage. And when or if it does heal will often include scar tissue that reduces its performance and or causes minor discomfort or pain

Consult a doctor before following any advice as there are a variety of treatments depending on the type, severity and location of the damage.

Typical treatments however usually include low impact stretching, heat therapy or compresses and deep tissue massage along with proper nutrition.

Basically in most cases you will want to keep it warm and flexible to encourage blood flow to the area but without adding weight or stress.

Also be extremely careful for the first few weeks after the pain has ceased (if it has ceased), because often even in cases where the tendon is healing, the knitted tissue is still softer than the surrounding tissue and prone to re tearing

If not properly cared for a tendon will develop knots and scar tissue and cause discomfort and pain for life even after it has healed to a usable form

You should pretty much treat it with care for as long as there is pain, and than for several weeks or months afterwards as well. It may be months or years or never to reach 100% recovery