Outcomes of Polyvinyl Alcohol Hydrogel Implant of the Lesser Metatarsals.

Background: Lesser toe metatarsophalangeal (MTP) joint pathology presents a challenge for surgical treatment. At our institution, arthroplasty using a polyvinyl alcohol (PVA) hydrogel implant has been utilized in the second and third MTP joints for advanced arthritis, failed management of Freiberg's infraction, and osteochondral defects. We present a case series describing the clinical outcomes of 13 patients following PVA implantation of the second or third MTP.
Methods: We retrospectively identified 13 patients (14 joints) who underwent PVA hydrogel implantation of the second ( n = 12) or third ( n = 2) metatarsal between 2017 and 2019. The average age was 49 (range, 20-67) years, with 100% females. Patient-Reported Outcomes Measurement Information System (PROMIS) scores were collected preoperatively and at an average of 21.1 (range, 8.3-29.2) months postoperatively. Clinical outcomes were also evaluated. The average time to clinical follow-up was 24.7 (range, 7-35.8) months.
Results: On average, patients demonstrated pre- to postoperative improvement in all PROMIS domains, with significant improvements in Pain Intensity ( P = .01) and Pain Interference ( P = .01). Five postoperative complications were observed: 1 case of persistent avascular necrosis, 1 revision with implant removal and bone grafting, 1 periprosthetic fracture, and 2 recurrences of pain requiring ultrasound-guided injection.
Conclusion: This study represents the largest case series to date evaluating the use of PVA 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.
Level of Evidence: Level IV, case series.