Flexible flatfoot is characterized by normal, non-weight bearing, medial longitudinal arch and loss of the medial arch of the foot while it contacts the ground with the heel valgus. Flexible flatfoot can occasionally be painful, after long periods of standing, walking, or intense exercises. Recent studies expressed subtalar arthoereisis is effective and safe (procedure of placing a motion blocking implant so that restrict subtalar joint pronation and make the weight-bearing posture of the foot better). It is considered a safer minimally invasive technique than other soft tissue procedures and bony procedures (osteotomies and arthrodeses). The study aimed to compare and evaluate the clinical and radiological results as well as complication rates of the two most used techniques of subtalar arthroereisis; self-locking and impact-locking devices in the treatment of flexible flatfoot. Patients and Methods: A prospective randomized study on thirty patients (44 feet) between four to Twenty years with symptomatic flexible flatfoot compared two methods of arthroereisis; the first method was Self-locking implants while the second method was Impact- blocking devices. Clinical and radiological evaluation pre and postoperatively done and patients follow up every 3 months for possible complications. The mean follow-up period was 10 months (range of 7-12 months). Results: All clinical and radiological parameters were improved for the 2 implant groups with no differences statistically between both techniques. There were 8 complications in our study. The self-locking implants had 3 complications; 1 patient had inflammation around sinus tarsi and 2 (8.7%) patients had intolerance of the screw and pain three months after surgery. The impact-blocking devices had 5 complications; 1 (4.8%) patient had a residual deformity and 1 (4.8%) other had to remove the screw at 12 months because of its displacement and 3 (19%) patients had pain and intolerance of the screw at three months after surgery. Conclusions: According to the present study, both surgical techniques showed satisfactory and constant clinical and radiographic correction of the deformity in short-term follow-up, with no statistical differences of significance regarding radiographic and clinical variables.

Flatfoot; subtalar arthroereisis; pes-planus