A placebo-controlled study comparing the efficacy of intra-articular injections of hyaluronic acid and a novel hyaluronic acid-platelet-rich plasma conjugate in a canine model of osteoarthritis.

The purpose of this study was to assess the efficacy of intra-articular injection of hyaluronic acid (HA) and a novel, where the conjugate of HA with fibrinogen autologous be platelet rich plasma (HA-PRP) in a canine model of osteoarthritis (OA) METHOD: Twelve Donkey Serum beagle dogs underwent unilateral resection of the cranial cruciate ligament (CrCl) of the joint crippling. clinical signs and radiographic OA was confirmed in all dogs 8 weeks after CrCl resection and before treatment.

 The dogs were randomized into three groups: saline (n = 4), HA (n = 4), and HA-PRP (n = 4). Each dog receives intra-articular injections of each substance into the affected joint in a pre-determined point in time. The dogs were assessed for adverse events during 3 days after each injection and for lameness, pain, range of motion, kinetics, and radiographic OA severity before treatment and 3 months after injection. 

OA severity as determined by radiographic examination did not differ significantly between the groups at any time point. The dogs were then humanely euthanatized and stifle joints assessed by gross and histologic examinations.Dogs treated with four weekly injections of HA or two bi-weekly injections of HA-PRP was significantly (p <0.05) better than dogs treated with four injections weekly saline at 2-, 4- and 12-week time point based on a variety of comfortable motion (CROM) and clinical lameness scores.

 Gait analysis to measure the symmetry and weight distribution on the pressure sensor showed significantly (p <0.05) improved limb function for dogs treated with HA and HA-PRP as compared to dogs treated with salt, but with a better clinical outcome for the group HA -PRP-treated at 12 and 20 weeks of follow-up. Dirty and histological analysis of the synovium and articular cartilage showed significant improvement (p <0.05) by both treatment groups compared to controls.

 There is however a significant (p <0.05) less damage to cartilage in the PRP group compared with the HA-HA-treated group.These data showed that while Equine Serum injection of HA and HA-PRP may be sufficient for short-term improvement of symptoms associated with OA, treatment with HA-PRP conjugate may be superior, providing a significantly better long-term preservation of cartilage.