Patient presents with complaints of chronic left hip pain, stiffness, and limited range of motion consistent with osteoarthritis.  Symptoms include difficulty walking, impaired mobility, and pain exacerbated by weight-bearing activities.  On physical examination, decreased left hip flexion, internal rotation, and abduction were noted, along with crepitus on movement.  Radiographic imaging of the left hip revealed joint space narrowing, osteophyte formation, and subchondral sclerosis, confirming the diagnosis of osteoarthritis.  Conservative management including physical therapy, NSAIDs, and activity modification has provided insufficient relief.  The patient is scheduled for a total left hip arthroplasty (THA), also known as left hip replacement surgery, to alleviate pain, improve function, and restore mobility.  Risks and benefits of the procedure, including potential complications such as infection, dislocation, and deep vein thrombosis, were discussed with the patient, and informed consent was obtained.  Preoperative clearance and optimization of medical comorbidities are underway.  Postoperative care will include pain management, physical therapy, and anticoagulation therapy as indicated.  ICD-10 code M16.11 (Primary osteoarthritis, left hip) and CPT code 27130 (Total hip arthroplasty) are relevant for this case.  Keywords: Left hip pain, hip osteoarthritis, total hip arthroplasty, THA, hip replacement surgery, joint pain, limited mobility, hip replacement recovery, postoperative care, ICD-10 M16.11, CPT 27130, physical therapy, osteoarthritis treatment, hip surgery.