Radiographic analysis of proximal interphalangeal joint arthrodesis with an intramedullary fusion device for lesser toe deformities.

Background: Lesser toe deformities are frequent and bothersome conditions. Many options exist for the treatment of hammertoes and clawtoes. The purpose of this study was to review our experience with the use of an intramedullary fusion device.
Materials and Methods: An IRB approved retrospective review was performed to identify 38 toes in 27 patients treated with the StayFuse (Nexa Orthopaedics) device with a mean followup of 31 months. The indications for surgery were primary deformity in 12 toes and recurrent deformities in 26 toes.
Results: Union occurred in 23 of 38 (60.5%). The union rate was nine of 12 for primary procedures and 53.8% (14/26) for revisions. Coronal PIP alignment demonstrated no change in 33 of 38 cases (86.8%) and changed in five of 38 (13.2%). Sagittal PIP alignment demonstrated no change in 36 of 38 cases (94.7%), and changed in 2/38 (5.3%). Including nonunion, the overall complication rate was 55.3% (21/38) (15 nonunions; three hardware failures (two (bent) not requiring intervention and one (broke) leading to a rotational deformity requiring revision), one intraoperative fracture (without sequelae), one requiring MP surgery, and one requiring a larger implant. The index surgery for all three of the patients that required a second surgery was for a recurrent deformity. All three patients requiring a second surgery occurred in the nonunion group.
Conclusion: The StayFuse intramedullary fusion device was efficacious in maintaining PIP alignment in the treatment of lesser toe deformities with a relatively low reoperation rate at mid-term followup.