Stabilization of proximal interphalangeal joint in lesser toe deformities with an angulated intramedullary implant

Hammertoe and claw toe are among the most common foot deformities. Proximal interphalangeal (PIP) joint realignment can be performed using specifically designed intramedullary implants. The aim of this study was to assess the clinical outcome of patients with lesser toes deformities undergoing PIP joint realignment using an intramedullary implant.

Patients requiring PIP joint realignment were included in this prospective multicenter observational study and followed for 12 months. A total of 156 toes, in 117 patients were implanted with the implants. Complications and radiological and functional outcome were assessed.

The proportion of joints fused on X-rays was 83.8% (95% CI: 77.8, 89.7) after 1 year. American Orthopaedic Foot and Ankle Society lesser metatarsophalangeal-interphalangeal scale (AOFAS-LMIS) improved from 40.4 (SD = 18.3) preoperatively to 85.5 (SD = 9.2) after 1 year. The proportion of patients with pain was 15.5% after 6 weeks and decreased to 4.7% after 1 year. Of the patients, 98% were satisfied about the operation. In patients with incomplete fusion of the PIP joint after 1 year, AOFAS-LMIS improved from 36.7 (SD = 18.9) preoperatively to 84.2 (SD = 10.1) 1 year postoperatively, while pain was reported by 2 patients (8.3%) after 1 year. Toe malalignment and lack of toe pulp-contact were reported slightly more frequently than for the whole group of patients, but not for the majority of the cases. Overall, complications were reported intraoperatively in 1.3% of the patients (2 cases) and postoperatively in 3.2% (5 cases). Revision was required in 1 case. Mallet toe deformity was found in 2.0% of the patients after 1 year.

This study showed that the use of an intramedullary implant for PIP realignment led to a high rate of fusion and a good outcome. No need of reoperation was reported for patients with incomplete joint fusion who had a stable joint with no pain.

Level IV, prospective case series.