The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine . 
There are two crescent-shaped menisci in each knee that act as shock absorbers between the tibia (shinbone) and femur (thighbone). For those born with discoid meniscus, one of the menisci in their knee is thicker than normal and may be shaped more like an oval. Those with this congenital defect are more prone to injury and may not know about it until they get hurt. The most common symptoms of discoid meniscus or a torn discoid meniscus include pain, stiffness, swelling, catching/popping/locking of the knee, inability to fully straighten the knee or feeling like the knee is giving way. If the discoid meniscus isn’t causing any problems, your orthopedic surgeon may not prescribe any treatment, but surgery is necessary to relieve pain or repair tears.