Joint contracture is reduced by intra-articular implantation of rosiglitazone-loaded hydrogels in a rabbit model of arthrofibrosis

Trauma, surgery, and other inflammatory conditions can lead to debilitating joint contractures. Adjunct pharmacologic modalities may permit clinical prevention and treatment of recalcitrant joint contractures. We investigated the therapeutic potential of rosiglitazone by intra-articular delivery via oligo[poly(ethylene glycol)fumarate] (OPF) hydrogels in an established rabbit model of arthrofibrosis. OPF hydrogels loaded with rosiglitazone were characterized for drug elution properties upon soaking in minimum essential media (MEM) with 10% fetal bovine serum and measurements of drug concentrations via High Performance Liquid Chromatography (HPLC). Drug-loaded scaffolds were surgically implanted into 24 skeletally mature female New Zealand White rabbits that were divided into equal groups receiving OPF hydrogels loaded with rosiglitazone (1.67 mg), or vehicle control (10 µl DMSO). After 8 weeks of joint immobilization, rabbits were allowed unrestricted cage activity for 16 weeks. Contracture angles of rabbit limbs treated with rosiglitazone showed statistically significant improvements in flexion compared to control animals (mean angles, respectively, 64.4° vs. 53.3°, p < 0.03). At time of sacrifice (week 24), animals in the rosiglitazone group continued to exhibit less joint contracture than controls (119.0° vs. 99.5°, p = 0.014). The intra-articular delivery of rosiglitazone using implanted OPF hydrogels decreases flexion contractures in a rabbit model of arthrofibrosis without causing adverse effects (e.g., gross inflammation or arthritis). Statement of Clinical Significance: Post-traumatic joint contractures are common and debilitating, with limited available treatment options. Pharmacologic interventions can potentially prevent and treat such contractures. This study is translational in that a commercially approved medication has been repurposed through a novel delivery device.