Question: A patient has been diagnosed with rectus femoris tendinitis. What would be the best CPT® code for an injection to treat the problem? Kansas Subscriber Answer: You actually have three options, as listed below. If your provider administered an injection in the tendon sheath, submit code 20550 (Injection[s]; single tendon sheath, or ligament, aponeurosis [e.g., plantar “fascia”]). If she injected the tendon origin or insertion, report 20551 (Injection[s]; single tendon origin/insertion). Finally, if your provider performed a nerve block injection was performed, file with either 64447 (Injection, anesthetic agent; femoral nerve, single) or 64450 (Injection, anesthetic agent; other peripheral nerve or branch). This tactic to treat the tendinitis is rather rare. Anatomy refresher: The rectus femoris muscle is one of the four muscles that make up the quadriceps muscles that run down the front of the thigh. The rectus femoris tendon can become inflamed at the upper part near the origin at the hip. The main cause is overuse through kicking or explosive movements as in sprint starts