[SHORT-TERM EFFECTIVENESS OF Hyprocure SUBTALAR STABILIZATION IN TREATMENT OF ADOLESCENT FLEXIBLE FLATFOOT]

To evaluate the short-term effectiveness of Hyprocure subtalar stabilization for adolescent flexible flatfoot.

Between December 2013 and September 2015, 14 cases (26 feet) of adolescent flexible flatfoot were treated with Hyprocure subtalar stabilization. There were 10 males (18 feet) and 4 females (8 feet) with the average age of 14.5 years (range, 12-18 years). There were 12 cases (24 feet) of congenital flatfoot and 2 cases (2 feet) of flatfoot caused by neurological diseases. The preoperative pain visual analogue scale (VAS) was 4.2±0.4; the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and foot function score was 72.2±12.3. Simple Hyprocure subtalar stabilization was used in 8 feet, and a combination of minimally invasive percutaneous Achilles tendon lengthening or gastrocnemius lysis, preposing of posterior tibial tendon and spring ligament tightening surgery, or open dorsal medial cuneiform osteotomy and bone graft in 18 feet. The VAS score and AOFAS ankle and foot function score were used to evaluate the effectiveness. The talus-the first metatarsal angle (T1MT), the talus-the second metatarsal angle (T2MT), and talonavicular coverage angle (TCA) were measured on the anteroposterior X-ray film; the Meary's angle, calcaneal inclination angle (CI), and the talar declination (TD) were measured on the lateral X-ray film.

All incisions healed well. Two cases (2 feet) had tarsal sinus pain, which was cured after symptomatic treatment. All patients were followed up 5-24 months (mean, 14.5 months). Pain was obviously relieved. At last follow-up, VAS score was significantly decreased to 1.4±0.3 (t=27.676, P=0.000). AOFAS ankle and foot function score was significantly increased to 94.5±10.8 (t=7.765, P=0.000). The postoperative X-ray film showed that medial arch was elevated after the Hyprocure subtalar stabilization was placed in tarsal sinus. At last follow-up, the T1MT, T2MT, TCA, Meary's angle, and TD were significantly improved when compared with preoperative ones (P<0.05); CI has no significant improvement (t=0.109, P=0.598).

Hyprocure subtalar stabilization is simple, effective for adolescent flexible flatfoot, the short-term effectiveness is good. But the indications should be strictly controlled, treatment should be individualized, corresponding auxiliary soft tissue and bone surgery is needed. The long-term effectiveness needs further follow-up.