Abstract
Purpose
Flat feet are an important cause of foot problems in children. The flexible flat foot is the most common form and is normally physiological and asymptomatic. Further assessment is necessary when a symptomatic flat foot persists. Surgical interventions are indicated when conservative therapies have failed. The Kalix arthroereisis is a surgical option and is placed in the subtalar joint of the foot, thereby preventing hyperpronation, and stabilizes the foot against excessive movements. The purpose of this study was to evaluate the functional and radiological outcomes of pediatric patients who had undergone a Kalix implantation for the treatment of a symptomatic flexible flat foot.
Methods
Patient files of our institution were searched for patients who underwent a Kalix implantation between 2009 and 2014. Sixteen patients (26 feet) with symptomatic flexible flat feet were clinically and radiographically evaluated in this retrospective study. The calcaneal pitch and Meary”s angle were measured on the pre-, and postoperative follow-up radiographs and patient satisfaction survey was performed at follow-up to gain insight into functional outcome and satisfaction after the intervention.
Results
Surgery was performed on an average age at 12.5 (range:10–15) years with a mean time from surgery to follow-up of 45.1±3.16 (range:18–78) months. There was a statistically significant increase in calcaneal pitch of 2.9° (11.7°to14.6°) and decrease in Meary”s angle of 15.8° (23.2° to7.85°) after surgery. The postoperative angles were maintained during follow-up, for both the calcaneal pitch (13.89°) and Meary”s angle (8.67°) in patients with the Kalix in situ (n=9/26) and in patients with the Kalix removed (15.4° and 7.8° respectively, n=17/26). The patient satisfaction survey shows that the majority of patients were satisfied regarding the state (81%) and appearance (75%) of their feet at follow-up. The majority never complained about their feet (81%) and heavy exercise was the major cause of complaints (23%). Limitations during walking were usually not the case (81%), though some patient experienced limitations during running (57%). Most reported preoperative complaints were pain, walking problems or a combination of both. The majority of these are relieved after surgery and patients were still asymptomatic at follow up.
Conclusion
Kalix implantation improves the calcaneal pitch and Meary”s angle, thereby restoring foot anatomy towards a normal anatomy. These improvements were observed directly postoperatively and remained at follow-up. In addition, relieve of symptoms was observed postoperatively and the majority of patients were even satisfied at follow-up. We therefore suggest that Kalix arthroereisis is an appropriate treatment option for pediatric patients with symptomatic flexible flat feet.
Significance
This was the first study evaluating functional and radiological outcomes of the Kalix arthroereisis in patients with symptomatic flexible flat feet.
