[Medial displacement calcaneal osteotomy with mini-incision for the treatment of acquired flexible flatfoot caused by posterior tibial tendon dysfunction].

OBJECTIVE: To investigate the clinical outcomes of medial displacement calcaneal osteotomy with mini-incision for the treatment of acquired flexible flatfoot caused by posterior tibial tendon dysfunction.

METHODS: From 2005 to 2009, 10 patients (13 feet) of acquired flexible flatfoot with obvious heel valgus underwent medial displacement calcaneal osteotomy with mini-incision. The lateral skin incision of 3.0 - 4.5cm was made to explore the lateral calcaneal wall. Calcaneal osteotomy was performed from inferior and lateral to superior and medial, perpendicular to the longitudinal axis of calcaneal body. The distal segment was displaced medially for 1/3-1/2 width of calcaneal body and fixed by two parallel cannulated screws. All patients were evaluated at 6 weeks, 3 months, 6 months, 12 months and every 6 months pre- and post-operatively by clinical examinations and radiological studies. All patients were physically examined with an extended protocol of questionnaires and the AOFAS Ankle & Hindfoot Scales. The lateral view of full foot allowed an assessment of bone healing, calcaneus inclination angle (CI), talocalcaneal angle (TC) and talar first metatarsal angle (TMT). The AP view of full foot allows assessment of TC and TMT. The heel varus/valgus alignment could be evaluated on the axial radiographs of hindfoot.

RESULTS: With a mean postoperative follow-up period of 20.3 months (range 7 - 55 Ms), all patients had bone union as confirmed by clinical examination and radiology. The AOFAS rating scale improved from a pre-operative mean of 50.3 to a mean of 80.2 at 6 months and a mean of 84.2 at last follow-up, without any complication of infection, nerve injure and so on. All radiographic parameters were statistically significant (P < 0.001), including CI, TC and TMT on the lateral view and TC and TMT on the AP view. The heel varus/valgus was corrected on the axial view.

CONCLUSION: The medial displacement calcaneal osteotomy with mini-incision is a recommended procedure for the treatment of acquired flexible flatfoot with excellent clinical outcomes, correction of deformity and fewer complications.