Body Weight Effects on Extra-Osseous Subtalar Arthroereisis

Area of Science:

• Orthopedic Surgery
• Pediatric Orthopedics
• Biomechanical Engineering

Background:

• Implant extrusion is a frequent complication of subtalar arthroereisis for pediatric flexible flatfoot.
• Limited research exists on the impact of body weight on implant extrusion post-subtalar arthroereisis.

Purpose of the Study:

• To investigate the relationship between body mass index (BMI) and implant extrusion after subtalar arthroereisis.
• To evaluate the effect of BMI on postoperative outcomes in pediatric patients undergoing this procedure.

Main Methods:

• Retrospective analysis of 102 pediatric patients (102 feet) undergoing the Vulpius procedure for subtalar arthroereisis.
• Data collected over a 24-month follow-up period, comparing patients with implants in situ versus those with implant extrusion.
• Analysis of demographic data, BMI, and radiographic measurements (Meary's angle, talonavicular angle, talar inclination angle).

Main Results:

• The implant extrusion group had a significantly higher mean BMI (21.2) compared to the implant in situ group (19.5).
• Overweight patients (BMI ≥ 24) showed a higher incidence of bilateral extrusion (39.3%) compared to the low body weight group (BMI ≤ 18.5) (23.2%).
• While both groups showed radiographic correction, the implant in situ group had superior postoperative Meary's, talonavicular, and talar inclination angles.

Conclusions:

• Elevated BMI is associated with an increased risk of implant extrusion and less favorable surgical outcomes after subtalar arthroereisis.
• Further prospective studies are needed to determine if preoperative weight loss can enhance surgical results in this patient population.