Surgical Treatment Of Flatfoot Without Posterior Tibial Tendon Dysfunction

ObjectiveWe did this study to classify different degree of flatfoot deformity without posterior tibial tendon dysfunction.By using different methods to treat different type of flatfoot,we try to evaluate and analyze the outcomes of these methods.MethodsFrom January 2011 to December 2015,62 patients(78 feet)have been followed up.These patients were classified ito 3 groups.Group 1: subtalar arthroereisis group with hindfoot valgus angle smaller than 10° and talonavicular coverage angle smaller than 20°.Group 2: subtalar arthroereisis combined with single calcaneal osteotomy,hindfoot valgus angle larger than 10° with or without talonavicular larger than 20°.Group 3: double calcaneal osteotomy group with or without subtalar arthroereisis,hindfoot valgus angle larger than 15°,talonavicular coverage angle larger than 20° with or without talo-first metatarsal angle in lateral view larger than 20°.The American Orthopaedic Foot & Ankle Society-ankle and hindfoot(AOFAS)score was adopted to evaluate the function of foot.ResultsAll patients completed the follow-up.The number of patients in Group 1 was 27(38 feet).The mean follow-up time was 40.8 months(31-65 months).The mean preoperative and postoperative hindfoot valgus angle were(9.2°±4.7°)and(2.3°±3.7°).The talonavicular coverage angle improved from(18.9°±11.3°)to(8.9°±6.5°).The talo-first metatarsal angle improved from(-18.2°±7.3°)to(7.9°±3.1°).The talar pitch angle improved from(37.9°±4.5°)to(27.2°±5.1°).And the AOFAS score improved from(81.5±7.8)to(97.5±4.6).The number of patients in Group 2 was 20(24 feet).The mean follow-up was 33.9±6.9 months(28-48 months).The mean preoperative hindfoot valgus angle,talonavicular coverage angle,talo-first metatarsal angle,talar pitch angle and calcaneal pitch angle were(14.9°±4.2°),(30.5°±9.4°),(-22.1°±7.9°),(36.1°±4.4°),(36.1°±4.4°),respectively.The mean postoperative hindfoot valgus angle,talonavicular coverage angle,talo-first metatarsal angle,talar pitch angle and calcaneal pitch angle were(2.3°±1.7°),(2.3°±1.7°),(-6.2°±4.7°),(27.3°±4.9°),(19.0°±4.3°),respectively.The AOFAS score improved from(66.8±24.1)to(96.5±3.4).The number of patients in Group 3 was 15(16 feet).The mean follow-up was 32.5±15.7 months(19-58 months).The mean preoperative hindfoot valgus angle,talonavicular coverage angle,talo-first metatarsal angle and talar pitch angle were(16.5°±4.1°),(24.9°±8.5°),(-18.1°±5.5°),(36.4°±4.7°),respectively.The mean postoperative hindfoot valgus angle,talonavicular coverage angle,talo-first metatarsal angle and talar pitch angle were(2.9°±1.6°),(6.5°±3.6°),(-4.9°±4.4°),(24.0°±5.6°),respectively.The AOFAS score improved from(68.9±12.3)to(94.6±3.9).All the p values above were smaller than 0.05.ConclusionSubtalar arthroereisis is effective for flatfoot patients with hindfoot valgus angle smaller than 10° and talonavicular angle smaller than 20°.Subtalar arthroereisis combined with calcaneal osteotomy is effective for flatfoot patients with hindfoot valgus angle larger than 10° with or without talonavicular coverage angle larger than 20°.And double calcaneal osteotomy or double calcaneal combined with subtalar arthroereisis is effective for flatfoot patients with hindfoot valgus angle larger than 15°,talonavicular larger than 20° and with or without talo-first metatarsal angle in lateral view larger than 20°.So for different kinds of flatfoot without posterior tibial tendon dysfunction,adoption of different methods will achieve good results,relieve patients' symptom and restore foot alignment.