en Orthopedy Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> <span lang="EN">Treatments for osteoarthritis, including steroids and nonsteroidal anti-inflammatory drugs, are not very satisfactory. Therefore, we decided to compare the therapeutic results of intra-articular injection of hyaluronic acid and methylprednisolone.</span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> <span lang="EN">In this single-blind clinical trial, 132 patients with osteoarthritis of the knee were randomly assigned to two treatment groups; hyaluronic acid and methylprednisolone. Treatment results were measured based on the standard McMaster Universities Arthritis Index (WOMAC) questionnaire.</span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b><span lang="EN"> Although the desired level of satisfaction was higher in the short-term in the methylprednisolone group and in the long-term in the hyaluronic acid group, however, these differences were not significant.</span><span style="font-size:10.0pt"></span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> The recovery of patients is better with methylprednisolone injection in the short term and hyaluronic acid in the long term. However, since methylprednisolone has complications, it is recommended to consider hyaluronic acid as a suitable drug in the treatment process.</span></span></span><br> &nbsp; ‌ Knee Osteoarthritis, Intra-Articular Injection, Hyaluronic Acid, Methylprednisolone 437 443 http://caspjim.com/browse.php?a_code=A-10-3357-1&slc_lang=en&sid=1 Seyyed Reza Aghapour dr.rezaaghapour@gmail.com 100319475328460053267 100319475328460053267 No Clinical Research Development Center, Shahid Beheshti Hospital, Babol University of Medical Sciences, Babol, Iran. Hamid Mohammadi hamidmohammadi600@yahoo.com 100319475328460053268 100319475328460053268 No Mazandaran University of Medical Sciences, Mazandaran, Iran. Seyyed Poyan Aghapour dr.aghapour@gmail.com 100319475328460053269 100319475328460053269 Yes Sari Branch, Islamic Azad University, sari, Iran Khashayar Farnoud farnood.kh@iums.ac.ir 100319475328460053270 100319475328460053270 No Medical student, Iran University of Medical Sciences, Tehran, Iran Yasin Sharifzadeh dryasinsharifzadeh@gmail.com 100319475328460053271 100319475328460053271 No Clinical Research Development Center, Shahid Beheshti Hospital, Babol University of Medical Sciences, Babol, Iran.