396 THE JOURNAL OF BONE AND JOINT SURGERY THE MILLER PROCEDURE FOR MOBILE FLAT FEET

We studied the long-term results of the Miller operation at a mean age of 13 years in 22 patients (38 feet) with persistently symptomatic mobile flat feet associated with an isolated naviculocuneiform break. At a mean of 12 years (3 to 27) after surgery, 84 % of the feet had a satisfactory clinical result. We conclude that the Miller operation is a useful procedure for adolescent patients with persistently symptomatic flat feet with an isolated break at the naviculocuneiform joint. J Bone Joint Surg [Br] 1995:77-B:396-9. In adolescent patients, mobile flat feet are usually asympto-matic; minor complaints of foot strain and excessive shoe wear can be relieved by the use of orthoses (Coleman 1983). A few patients, however, may have severe persisting symptoms. The medial longitudinal arch of mobile flat feet with a break at the naviculocuneiform joint can be restored by full dorsiflexion of the great toe as can feet with a mild break at the tabonavicularjoint (Jack 1953). Standing lateral radiographs can be used to classify the deformity into one of three anatomical types (Jack 1953). The first is asso-ciated with an isolated tabonavicular break, and the talus is more vertical than normal because of severe laxity of the ligamentous and tendinous supports of the subtalar and tabonavicular joints. The second type has an isolated nay-iculocuneiform break and the third has a combined brea