Patient presents with complaints of left knee pain, instability, and swelling following a non-contact twisting injury during a basketball game.  Onset of symptoms was acute, occurring approximately one week ago.  Patient reports a "popping" sensation at the time of injury followed by immediate pain and difficulty weight-bearing.  Physical examination reveals tenderness along the joint line, positive Lachman test, positive anterior drawer test, and mild effusion.  McMurray's test was negative, suggesting no meniscus involvement.  Range of motion is limited due to pain and swelling.  Differential diagnosis includes anterior cruciate ligament (ACL) tear, medial collateral ligament (MCL) sprain, and patellar tendonitis.  Pre-injury activity level was high, participating in competitive sports.  Current activity level is significantly limited due to pain and instability.  Assessment: Left knee ACL tear.  Plan: MRI of left knee is ordered to confirm the diagnosis and evaluate for any associated injuries.  Conservative treatment options including bracing, physical therapy, and activity modification will be discussed.  Surgical reconstruction of the ACL will be considered based on MRI findings, patient's activity level, and functional goals.  Patient education provided regarding ACL injury, treatment options, and expected recovery.  Follow-up appointment scheduled in one week to review MRI results and discuss treatment plan.  ICD-10 code: S83.511A  (Sprain of anterior cruciate ligament of left knee, initial encounter).