Abstract
Category:
Midfoot/Forefoot; Basic Sciences/Biologics
Introduction/Purpose:
A polyvinyl alcohol hydrogel implant (Cartiva Synthetic Cartilage Implant) has recently been developed, which has a water content comparable to healthy cartilage and a compressive modulus and tensile strength similar to human articular cartilage. These biomechanical features have been thought to be an ideal material for use in hemiarthroplasty of the first MTP joint. The purpose of this study is to evaluate the clinical, functional and radiological outcomes following a polyvinyl alcohol hydrogel implant for the treatment of hallux rigidus.
Methods:
A retrospective cohort study investigating patients treated with polyvinyl alcohol hydrogel implant for hallux rigidus was performed. Patients who had grade 2, 3 or 4 hallux rigidus based on Coughlin classification were indicated. Clinical outcomes were evaluated with the Foot and Ankle Outcomes Score (FAOS) and Visual Analog Score (VAS) preoperatively and at final follow-up. Plain radiographs were assessed postoperatively at 2, 4, 8 weeks and final follow-up.
Results:
Fifteen patients (15 feet) with mean follow-up of 19.0 months (12-26 months) were included. The mean age was 61.1 years. FAOS-reported symptoms, pain, daily activities, sports activities, and quality of life were 62.3, 69.8, 74.5, 49.7, and 36,3 post-operatively, respectively. Of 14 patients who had taken adequate postoperative plain radiographs, implant subsidence was observed in 9 patients (64%) at 4 weeks after surgery and 11 patients (79%) at final follow-up. . Eight patients (57%) showed radiologic lucency around the implant. Six patients (40%) had erosion of the proximal phalanx of great toe. Six patients(43%) reported no improvement following surgery at final follow up. Three patients required additional surgery, including debridement and fixation of implant using fibrin glue for loosening.
Conclusion:
Our current study revealed a high failure rate with the polyvinyl alcohol hydrogel implant in patients with Hallux Rigidus. Significant radiologic subsidence with lysis around the implant, erosion of the proximal phalynx countersurface as well as recorded implant wear are harbingers for concern in the long term.