Reconstruction of the pediatric flexible planovalgus foot by using an Evans calcaneal osteotomy and augmentative medial split tibialis anterior tendon transfer.

Seventeen consecutive pediatric patients (34 feet) underwent reconstruction of flexible pes planovalgus deformity between 1994 and 1999. The average follow-up was 24.9 months (range, 8 to 48 months). All patients underwent a medial split tibialis anterior tendon transfer/tenodesis in combination with an Evans calcaneal-lengthening osteotomy, Kidner or modified Kidner procedure, and tendo-Achilles lengthening. Various angular parameters were measured both preoperatively and postoperatively, and improvement in each was noted. The calcaneal pitch improved by an average of 26 degrees (85.88%), the lateral talometatarsal angle improved by an average of 26.4 degrees (96.15%), the lateral talocalcaneal angle improved by an average of 14.8 degrees (34.26%), the anteroposterior talometatarsal angle improved by an average of 21.9 degrees (81.92%), the anteroposterior talocalcaneal angle improved by an average of 15.9 degrees (37.95%), the cuboid abduction angle improved by an average of 13.8 degrees (87.34%), and the talonavicular coverage angle improved by an average of 26.7 degrees (94.68%). Postoperative improvement of all angular measurements was statistically significant at the 95% confidence level (P =.05). In addition, American Orthopedic Foot and Ankle Society hindfoot/ankle scoring was performed preoperatively, 3 months after the second foot surgery, and at the time of maximal follow-up. A preoperative average score of 68.59 improved to 85.76 at 3 months after the second foot surgery, and improved to 96.55 at the time of the last follow-up. All 17 patients were satisfied with their surgical result because all returned for correction of the contralateral foot. All patients indicated a uniform willingness to have these procedures performed again.