RADIOGRAPHIC AND CLINICAL CLASSIFICATION OF ACQUIRED MIDTARSUS DEFORMITIES

To develop a classification of midtarsus deformities, clinical examina tion and weightbearing radiographs were used to evaluate 131 feet in 1 09 patients (average age, 59 +/- 11 years) with those deformities. Pat ients were classified into four types based on anatomic location of th e maximum deformity. Type I (N = 43) showed deformity at the metatarso cuneiform joints medially and the fourth and fifth metatarsocuboid joi nts laterally, with plantarmedial and/or medial prominence. Type II (N = 60) had deformity at the naviculocuneiform joint medially and the f ourth and fifth metatarsocuboid joints laterally; plantarlateral promi nence was characteristic, although one-third had isolated or additiona l medial prominences. Type ill (N = 17) had major deformity in the per inavicular region, with a prominence plantarcentrally or plantarlatera lly. Type IV (N = 11) had deformity at the transverse tarsal joints wi th variable prominences. Each type was further subdivided into stages A, B, and C based on the severity of the deformity. In stage B, the mi dtarsus was coplanar with the metatarsocalcaneal plane. In stage A, th e midtarsus was above this plane. In stage C, the midtarsus was below this plane. We concluded that midtarsus deformities can be classified as one of four types and one of three stages. Additional study is warr anted to correlate this system with prognosis and treatment for this p athologic process.