Dai L, Zhang X, Mei Y, et al. - This study was intended to distinguish the clinical features of intra-articular osteoid osteoma (OO) of the hip, to assess the clinical effect of arthroscopic excision for intra-articular OO to conclude the characteristics of revision cases of hip OO and the revision surgery under arthroscopy on these cases. The data of 25 patients who had undergone arthroscopic excision of hip OO were retrospectively examined. Ten individuals who had undergone revision surgery were enrolled in this case series. Researchers examined lesion location, presenting symptoms, and symptom duration; postoperative improvement was evaluated using the modified Harris Hip Score and international Hip Outcomes Tool (iHot-12) scores. They analyzed the reasons for the need for revision surgery and the characteristics of OO progression after the first surgery. As per the findings, OO of the hip joint typically presents with pain and limited joint activity. This study’s findings demonstrate that misdiagnosis as FAI or synovitis is common and so that patient who has limit ROM, night pain and can be relieved by NASIDs should be suspected OO, and more advanced radiological evaluation, such as CT scan, should be performed. For the treatment of OO of the hip joint, arthroscopic excision seems to be an effective method.