Patella infra and fat-pad hypertrophy after total knee arthroplasty

Tethering of the patellar tendon with a resultant patella baja and hypertrophy of the infrapatellar fatty tissue are two rare causes of anterior knee pain after total knee arthroplasty. Symptoms are varied, with limitation of flexion due to anterior pain or pain during extension being the most common. Examination is not very helpful, except for the patella, which may have a rubbery feeling on transverse motion. Relief of discomfort by injecting a local anesthetic within the joint warrants an arthrotomy if conservative measures have failed to relieve symptoms. Surgical excision of the hypertrophied adipose and fibrous tissue and freeing of the quadriceps—patella—patellar tendon has been very effective in relieving pain and increasing motion.