Background: The use of an arthroereisis implant for the treatment of adolescent flatfoot deformity has been described. However, data that address the outcomes of patients treated with an arthroereisis implant in adults are limited. The purpose of this study was to investigate the radiographic and clinical outcomes and complications following the use of a subtalar arthroereisis implant as an adjunct for correction acquired flatfoot deformity secondary to posterior tibial tendon dysfunction.
Methods: A retrospective case-control study was performed querying all patients undergoing surgical flatfoot correction between January 1, 2010 and January 1, 2015. The experimental group included patients undergoing arthroereisis augmentation at the time of flatfoot correction. Patients undergoing the same flatfoot correction without the use of an arthroereisis implant were used as controls. Radiographic measurements were evaluated preoperatively and at final radiographic follow-up and included talonavicular (TN) coverage angle, and lateral talar-first metatarsal angle (T1MA). Patient-reported outcomes were assessed using preoperative visual analog scale (VAS) pain scores and postoperative Short Form-36, VAS, and satisfaction at final orthopedic follow-up.
Results: A total of 15 patients underwent flatfoot correction and were augmented with an arthroereisis implant and were matched with 30 controls. Postoperative, mid-term T1MA and regional analysis was found to be improved in the experimental group versus control. Patients undergoing adjunct subtalar arthroereisis demonstrated an increased likelihood of achieving radiographically normal talonavicular coverage <7° compared with our control group at follow-up.
Conclusions: The adjunct use of an arthroereisis implant resulted in improved and maintained radiographic and clinical measurements in patients undergoing stage II flatfoot.
Clinical significance: These results suggest utility of a subtalar arthroereisis implant as an adjunct to flatfoot correction with little additional risk of harm to the patient.
Levels of evidence: Level III: Case-control study.
Keywords: adult-acquired flatfoot deformity (AAFD); arthrodesis; calcaneo-valgus deformity; flatfoot; pes planus; posterior tibial tendon dysfunction (PTTD).