The study is an interventional, randomized, open-label (non-blinded), placebo-controlled trial. Preoperatively, patients scheduled for primary total hip arthroplasty (THA) will undergo a clinical examination in the Orthopaedic Department. Clinical tests will be performed to confirm sacroiliac joint (SIJ) dysfunction on the operated side. In addition, low-dose computed tomography (CT) will be used to assess structural changes in the SIJ.
All patients will complete patient-reported outcome measures related to the hip joint, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS), as well as SIJ-related assessments, including the Oswestry Disability Index (ODI). Pain intensity will be assessed using the Visual Analogue Scale (VAS).
Following THA, patients will be randomly allocated into two groups during their hospital stay. In the intervention group, platelet-rich plasma (PRP) will be injected into the sacroiliac joint, whereas the control group will receive an injection of normal saline. All injections will be performed in the operating theatre.
At discharge, patients will be scheduled for follow-up visits at 2, 6, and 12 weeks postoperatively. At each follow-up, patient-reported outcomes will be collected, including WOMAC and HHS for hip function, ODI for SIJ-related disability, and VAS for pain assessment of both the hip and sacroiliac joint.
primary osteoarthritis of the hip;
qualification for elective total hip arthroplasty (THA);
age ≥45 years;
written informed consent;
prior surgical treatment of the hip or sacroiliac joint;
malignancy;
developmental dysplasia of the hip;
rheumatologic diseases (rheumatoid arthritis, ankylosing spondylitis, juvenile idiopathic arthritis);