Orthobiologic injections for hip osteoarthritis: A systematic review of clinical outcomes

The incidence of hip osteoarthritis (OA) is increasing with the aging population, leading to interest in intra-articular orthobiologic injections to alleviate symptoms and potentially slow disease progression. This systematic review aims to evaluate the clinical outcomes associated with six orthobiologic therapies for hip OA: hyaluronic acid (HA), platelet-rich plasma (PRP), autologous cells therapy (ACT), microfragmented adipose tissue (MFAT), and bone marrow aspirate (BMA) and its concentration (BMAC).

We conducted a literature search according to the PRISMA guidelines. Studies were included in our review if they used at least one of the four orthobiologic therapies and reported on the clinical outcome using patient reported outcome measures (PROMs). Since there is a large variability among clinical outcomes, we focused on the three most utilized PROMs (VAS, WOMAC, and HHS) and the latest follow-up time point.

Of the 716 studies reviewed, thirty-six studies (n=36) fit inclusion criteria. There were 21 studies examining HA, 11 on PRP, 3 for MFAT, 2 for ACT, and 3 on BMA/BMAC. Eight studies were randomized controlled trials and 28 were cohort studies. The mean age of the patient population ranged from 45 ± 17.0 to 74 ± 8.0. The baseline grade of osteoarthritis ranged from 1-4 but was most reported as moderate (2-3). Overall, there was an improvement in PROMs at the latest follow-up after receiving orthobiologic interventions.

Orthobiologic injections have shown promise for improving PROMs in patients with hip OA. Future studies should evaluate long-term efficacy and include randomized trials to establish efficacy.