Patient Outcomes Following Polyvinyl Alcohol Hydrogel Implant of the Lesser Metatarsals

CATEGORY: Lesser Toes; Other INTRODUCTION/PURPOSE: Lesser toe metatarsal phalangeal (MTP) joint pathology presents a challenge for surgical treatment. Recently, synthetic cartilage implants have been shown to be safe and efficacious in treating hallux ridigus, offering pain relief while preserving motion at the MTP joint. At our institution, metatarsophalangeal joint arthroplasty using a polyvinyl alcohol (PVA) hydrogel implant has been utilized in the 2nd and 3rd MTP joints for advanced arthritis, failed management of Freiberg’s infraction, and osteochondral defects. We present a case series describing the clinical outcomes of 12 patients following PVA implantation of the 2nd or 3rd MTP. METHODS: We retrospectively identified 12 consecutive patients (13 joints) who underwent PVA hydrogel implantation of the 2nd (n=12) or 3rd (n=1) metatarsal head between 2017 and 2019. PVA implant was indicated for advanced arthritis in 6 patients (7 joints), Freiberg’s infraction in 4 patients, and osteochondral defect in 2 patients. Average age was 51 years (range, 20-67), with 100% females. Patient-reported outcomes measurement information system (PROMIS) scores were collected preoperatively and at latest follow-up, with an average follow-up of 20.4 months (range, 8.3 to 29.2). Retrospective chart review was performed to evaluate postoperative complications, including need for revision, implant removal, and persistent pain. RESULTS: Overall, patients demonstrated mean improvement in all PROMIS domains, with a significant improvement in Pain Intensity of 11.9 points (p=0.03) postoperatively. A total of 4 postoperative complications occurred in the 12 patients: one case of AVN at 2 years postoperatively, one revision with removal of the implant and bone grafting of the second metatarsal head at 1 year postoperatively, one periprosthetic fracture at 9 months postoperatively, and one recurrence of pain requiring ultrasound- guided injection at 7 months postoperatively. Three additional patients reported persistent pain postoperatively. CONCLUSION: This study represents the largest case series to date evaluating the use of PVA hydrogel implant in the surgical correction of lesser toe MTP joint pathology. While the PVA implant presents a viable option in the setting of advanced arthritis, Freiberg’s infraction, and certain osteochondral defects, it is not without complications. The specific indications for use of the PVA implant should be carefully considered before implantation.