Patient presents with complaints of left knee pain, stiffness, and reduced range of motion, consistent with primary osteoarthritis.  Symptoms include intermittent aching, creaking sensation, and morning stiffness lasting less than 30 minutes.  Onset of symptoms was gradual over the past year, exacerbated by weight-bearing activities and prolonged standing.  Patient denies any history of trauma, injury, or infection to the left knee.  Physical examination reveals palpable crepitus, mild joint effusion, and tenderness along the medial joint line.  Range of motion is limited in flexion and extension.  McMurray's test is negative.  Radiographic imaging of the left knee demonstrates joint space narrowing, osteophyte formation, and subchondral sclerosis, confirming the diagnosis of primary osteoarthritis.  Diagnosis codes include M17.11 (primary osteoarthritis left knee).  Treatment plan includes conservative management with NSAIDs for pain relief, physical therapy to improve range of motion and strengthen supporting musculature, and weight management counseling.  Patient education provided on joint protection strategies, assistive devices, and the importance of regular exercise.  Follow-up scheduled in four weeks to assess response to treatment and discuss further management options, including viscosupplementation or corticosteroid injections if symptoms persist.  Patient advised to return sooner if symptoms worsen or new symptoms develop.