Patient presents for follow-up evaluation status post total left knee arthroplasty (TKA).  The indication for the original procedure was primary osteoarthritis of the left knee with significant pain, functional limitation, and failure of conservative management including physical therapy, NSAIDs, and viscosupplementation injections.  The patient reports current left knee pain level as 2/10 at rest and 5/10 with ambulation.  Range of motion in the left knee is documented as 0 to 120 degrees of flexion.  There is no evidence of erythema, warmth, or effusion.  The surgical incision is well-healed.  Neurovascular examination of the left lower extremity is intact.  Radiographic imaging of the left knee demonstrates a well-positioned and stable prosthesis.  Assessment:  Status post left total knee replacement, improved range of motion and pain control. Plan:  Continue with home exercise program focusing on strengthening quadriceps and hamstrings.  Patient education provided regarding activity modification and pain management strategies.  Follow-up scheduled in 6 weeks to monitor progress and assess functional recovery.  ICD-10 code Z96.641 (Presence of left artificial knee joint) and CPT codes for evaluation and management services will be applied based on time and complexity of this encounter.  Differential diagnosis included post-operative stiffness, arthrofibrosis, and prosthetic loosening, which were ruled out based on clinical examination and radiographic findings. Keywords: total knee arthroplasty, TKA, knee replacement, osteoarthritis, post-operative care, rehabilitation, range of motion, pain management, ICD-10, CPT codes, medical billing, EHR documentation.