Treatment of Stage II Posterior Tibial Tendon Dysfunction with Flexor Hallucis Longus Transfer and Medial Displacement Calcaneal Osteotomy

Nineteen consecutive patients underwent flexor hallucis longus (FHL) tendon transfer and medial displacement calcaneal osteotomy for the treatment of Stage 2 posterior tibial tendon dysfunction. The FHL tendon was utilized for transfer because it approximates the strength of the posterior tibialis muscle and is stronger than the peroneus brevis muscle. Seventeen patients returned for follow-up examination, follow-up time 18 months (ave.). The AOFAS hindfoot score improved from 62.4/100 to 83.6/100. The subjective portion of the AOFAS hindfoot score improved from 31.0/60.0 to 48.9/60. Weightbearing preoperative and postoperative radiographs revealed no statistically significant improvement for the medial longitudinal arch in measurements of lateral talo-first metatarsal angle, calcaneal pitch, vertical distance from the floor to the medial cuneiform, or talonavicular coverage angle. Three feet had a normal medial longitudinal arch and six feet had a longitudinal arch similar to the opposite side following the procedure. Patient satisfaction was high: 10 patients satisfied without reservations, 6 patients satisfied with minor reservations, and 1 dissatisfied. No patient complained of donor deficit from the harvested FHL tendon. Despite the inability of the procedure to improve the height of the medial longitudinal arch, FHL transfer combined with medial displacement calcaneal osteotomy yielded good to excellent clinical results and a high patient satisfaction rate.