Efficacy of orthobiologic adjuvants to core decompression for hip preservation in avascular necrosis hip

Head preserving modalities in avascular necrosis (AVN) hip are variably effective in early stages, and further options that could prevent head distortion and osteoarthritis are needed. Core decompression (CD) is the most commonly used surgery in the early stages of osteonecrosis with variable rates of success. The present review aimed to determine the effectiveness of bone marrow aspirate concentrate (BMAC), platelet-rich plasma (PRP), bone morphogenetic proteins (BMP) or their combination with CD in early stages of AVN hip, prior to collapse of femoral head. Additionally, any newer unexplored modalities were also searched for and ascertained. PubMed and SCOPUS databases were searched for relevant articles in English language describing CD with aforementioned orthobiologics. We analysed a total of 20 studies published between 2011 and 2020. There were 6 retrospective and 14 prospective studies. PRP showed improved survival and functional outcomes; however, with only three studies, there is inconclusive evidence for its routine utilization. BMAC enhances the efficacy of CD which can further be increased by culture and expansion of cells or combining it with PRP to stimulate growth. In conclusion, CD with BMAC works more efficiently than CD alone prior to collapse of femoral head in AVN. However, PRP needs more evidence for extensive application. Addition of PRP to BMAC or culturing the latter could further enhance the potency of CD + BMAC combination. Very limited data is available for the efficacy of BMP-7 and the role of intraosseous bisphosphonates should be evaluated for a cheaper and potential alternative.