Randomized, double-blind, controlled trial, phase III, to evaluate the use of platelet-rich plasma versus hyaluronic acid in hip coxarthrosis.

AIMS OF THE STUDY

To compare efficacy and safety of a home-made platelet-rich plasma (PRP) solution versus hyaluronic acid in patients with hip osteoarthritis not responding to conservative treatment and to correlate cellular composition of PRP to clinical outcomes.

MATERIAL AND METHODS

This is a phase III clinical trial, double-blinded, controlled and randomised into two treatment groups (PRP and hyaluronic acid). Patients received one hip ultrasound-guided injection. Follow up was 12 months. Pain was assessed using VAS score, HHS and WOMAC were used as functional scores, analgesia, adverse events, cellular components (PRP group) in peripheral blood and in PRP were recorded. Clinical response was assessed using OARSI criteria.

RESULTS

Seventy-four patients were included. Both groups improved in VAS, WOMAC and HHS score and reduced the amount of analgesia (p<.05). Significant differences were seen at 1 year post-treatment in HHS score (PRP 70.9 [3.7-58], hyaluronic acid 60.2[43-74.2] p<.05). No adverse events were observed in none of the groups. Platelet concentration was different between responders and non-responders (at 1 month, non-responders 449[438-578] x103 platelets/μl versus responders 565 [481-666] x103 platelets/μl, p<.044). There was a correlation between leukocytes concentration and clinical scores (VAS at six months, r=0.748, p<.013, WOMAC at 6 months r=0.748, p <.013). Patients with early stage hip OA showed higher response rate to PRP compared with late stage (11.51 OR, 95%CI 2.34-50.65, p<.03).

CONCLUSIONS

Platelet-rich plasma injection improved hip function, reduced pain and the use of analgesia. It is important to bear in mind the cellular composition in order to achieve a better clinical response.