The restoration of the joint line is important for a good functional outcome after a Total Knee Arthroplasty(TKA). Knee joint biomechanics need to be restored as near normal as possible. Joint line elevation leads to anterior knee pain, decrease in range of motion, patella baja ,mid-flexion instability and impingement of patellar tendon. Joint line depression on the other hand leads to patella alta, risk of patellar subluxation and mid-flexion instability of the knee. Various studies have demonstrated various range of acceptable joint line variation but there is no clear acceptable range of joint line variation. More studies are required for establishing the acceptable range of joint line variation and standard practices should be established for arthroplasty surgeons for preventing variation of joint line.