HyProCure for Flatfoot Deformity: A Clinical Characteristics Analysis in China.

Background: Flatfoot is a common foot disorder involving progressive foot deformity of the three-dimensional structures of the forefoot, midfoot, and hindfoot. Currently, Chinese surgeons and patients favor subtalar arthroereisis (SA) due to its minimally invasive and low-damage characteristics. HyProCure device is widely used. However, there is limited analysis of large sample sizes. This study utilized statistical evaluation with a large sample size to analyze clinical characteristics trends of SA for flatfoot, including baseline indicators, selection of HyProCure size and surgical strategy, complications, and implant removal. This study will enhance the understanding of SA in China.

Methods: A retrospective analysis of 732 patients (1008 ft) who underwent SA from June 2015 to June 2023, with 509 pediatric and adolescent patients (772 ft) and 223 adult patients (236 ft). Based on the patient's age, patients aged ≤ 18 were included in the children and adolescent group, while adult acquired flatfoot deformity (AAFD) patients aged > 18 were included in the adult group. General data was collected, including patient sex, age, side, body mass index (BMI), surgery date, HyproCure size, and surgical data, and trends were analyzed. Postoperative complications and HyProCure removal were collected as outcome measures during follow-up.

Results: The age of patients treated with SA was gradually getting younger, with male patients predominating, mainly concentrated in the 11-14 age group. HyProCure 7 has the highest usage rate. In the children and adolescent group, 288 ft (37.31%) only underwent SA. In the adult group, 18 ft (7.63%) only underwent SA. Complications include sinus tarsi pain, peroneal spasms, achilles tendon tension, and muscle strength decline. The complication rate in the children and adolescent group was 5.05%, while in the adult group it was 28.81%. Overall, it was 10.62%. The removal rate of HyProCure in the children and adolescent group is 1.04%, in the adult group is 15.25%, and overall is 4.37%.

Conclusions: The trend in flatfoot treated with SA was towards children and adolescent male patients, and sinus tarsi pain was the most common complication after SA. The complication rate and removal rate in the children and adolescent group were lower than those in the adult group. HyProCure can be removed without additional adverse effects.