Orthobiologic therapies delay the need for hip arthroplasty in patients with avascular necrosis of the femoral head: A systematic review and survival analysis.

Purpose: The aim of this systematic review and survival analysis was to quantify the benefits of orthobiologic augmentation therapies for the treatment of avascular necrosis (AVN) of the femoral head and identify the most effective approach to delay the need for total hip arthroplasty (THA).

Methods: A systematic review of the literature was performed on PubMed, Scopus, and Cochrane on clinical studies on orthobiologic therapies used alone or as an augmentation to core decompression or other procedures to address hip AVN. A qualitative analysis of the different biological therapies applied was performed. Afterward, the results of these procedures were quantitatively analysed to document their survivorship from THA compared to treatment groups without orthobiologics. Kaplan-Meier analysis was performed for all studies and then by categorising orthobiologics into treatment subgroups.

Results: A total of 106 studies were included (4505 patients). Different orthobiologic approaches have been evaluated: cell-based therapies including bone marrow aspirate concentrate (BMAC) and bone marrow mesenchymal stromal cells (BM-MSCs), platelet-rich plasma (PRP), or other bioactive molecules applied in the osteonecrotic area or as intra-arterial injections. The survival analysis at 120 months documented a higher (p < 0.0005) cumulative survivorship with orthobiologics (69.4%) compared to controls (48.5%). The superiority was shown specifically for BMAC (p < 0.0005), BM-MSCs (p < 0.0005), intra-arterial (p < 0.0005) and PRP (p = 0.011) approaches, but the direct comparison of these approaches with their controls confirmed benefits only for BMAC (p < 0.0005).

Conclusion: This systematic review and survival analysis demonstrated that orthobiologics have the potential to improve survivorship in patients affected by hip AVN. In particular, the specific analysis of different orthobiologic products supported relevant benefits for BMAC augmentation in terms of survival from the need for THA, while no clear benefits were confirmed for other orthobiologics.

Level of evidence: Level III.