Patient presents with right knee pain, swelling, erythema, and warmth, consistent with suspected septic arthritis.  Onset of symptoms was reported as acute, beginning approximately three days prior to presentation.  Patient reports significant pain with any movement of the right knee and difficulty bearing weight.  Range of motion is severely limited due to pain and swelling.  Fever of 101.5 degrees Fahrenheit was documented.  Patient denies any recent trauma to the knee.  Medical history includes type 2 diabetes mellitus and hypertension.  Physical examination reveals marked tenderness to palpation of the right knee joint, with notable effusion.  Labs ordered include complete blood count with differential, erythrocyte sedimentation rate, C-reactive protein, and joint aspiration for synovial fluid analysis and culture.  Differential diagnosis includes gout, pseudogout, and reactive arthritis.  Given the clinical presentation and elevated inflammatory markers, septic arthritis of the right knee is the leading diagnosis.  Initial treatment includes intravenous antibiotics and pain management.  Orthopedic consultation is requested for possible joint drainage and further management.  Patient education provided regarding the importance of antibiotic adherence and follow-up care.  ICD-10 code M00.061 and CPT codes for joint aspiration and injection will be applied based on procedures performed.  Continued monitoring for response to treatment and potential complications is warranted.