Treatment of brachymetatarsia by distraction osteogenesis.

Metatarsal lengthening by distraction osteogenesis was performed on 17 brachymetatarsia patients with 39 metatarsal bones. To lengthen the first metatarsal in an attempt to prevent development of varus deformity of the hindfoot after lengthening, horizontal lengthening in the anterior direction was performed rather than lengthening through the anatomical axis. In addition, care was taken to ensure that the fourth metatarsal bone screw did not interpose with the fifth extensor tendon during the fourth metatarsal lengthening. Lengthening was successful except in 1 case with mean lengthening of 19.5 mm (48.8%) for the first metatarsal and 17.1 mm (36.2%) for the fourth metatarsal. Because of joint stiffness, plantar capsulotomy was performed on 7 cases, 6 of which had been previously operated on bilaterally. Varus deformity of the hindfoot after the first metatarsal lengthening and entrapment of the fifth extensor tendon after the fourth metatarsal lengthening was not detected in any case.