State of art in intra-articular hip injections of different medications for osteoarthritis: a systematic review

Background: Intra-articular hip injections for osteoarthritis represent a useful instrument to reduce pain and disability in the common clinical practice. Several medications can be injected locally with different level of evidence-based efficacy. Objective: The objective of this systematic review is to investigate the effectiveness of intra-articular injections of different medications or substances for the pain treatment and the management of disability in subjects affected by hip osteoarthritis. Methods: Two reviewers selected independently randomised controlled trials published in the last 10 years, using PubMed and Scopus databases. The risk of bias was evaluated with Cochrane library assessment tool. Results: 12 randomised controlled trials have been selected. We found 8 papers comparing hyaluronic acid with platelet rich plasma, with corticosteroids and with saline solution; 1 paper compares two types of hyaluronic acid with different molecular weights; 3 papers study the effects of corticosteroids alone or compared to ketorolac or saline solution. Conclusions: The studies reviewed were heterogeneous regarding sample size, level of osteoarthritis, evaluated with Kellegren-Lawrence score, medications used and follow up timings. However, we have observed that intra-articular injections of platelet-rich plasma seem to decrease pain at short term and disability at long term, in patients affected by hip osteoarthritis better than hyaluronic acid. The association of hyaluronic acid and corticosteroids could give better results compared to hyaluronic acid alone, while the use of intra-articular ketorolac and saline solution requires more studies.