First Metatarsophalangeal Joint Space Area Decreases Within 1 Month After Implantation of a Polyvinyl Alcohol...

In 2016, the U.S. Food and Drug Administration approved the first and only polyvinyl alcohol hydrogel implant for the treatment of hallux rigidus. The implant functions as a bumper to maintain first metatarsophalangeal joint space to prevent contact of the phalangeal base with the first metatarsal head. Short-term and intermediate outcomes with this implant have reported positive outcomes with no radiographic outcomes of implant wear or subsidence. We performed a retrospective radiographic review of 27 consecutive patients who received the implant and measured preoperative and postoperative joint space area (JSA). We found a significant improvement in JSA (p < .001) between the preoperative JSA and JSA at the first postoperative visit at 1 to 2 weeks. We also found a significant decrease in JSA (p < .001) between the first postoperative visit and the second postoperative visit at 5 to 12 weeks. This information could have further implications for implant design as well as how we can better achieve functional improvements in the first metatarsophalangeal joint in patients with hallux rigidus.