To report on a new operative technique of distraction osteogenesis and it's results in brachymetatarsia.

17 patients (39 metatarsal bones) formed the basis of this study (male: female-2: 15). To prevent varus deformity of the hindfoot after lengthening, all screws were inserted at the same level from the medial aspect of the first metatarsal bone for horizontal distraction in the anterior direction, rather than distraction in the direction of the anatomical axis. Also, care was taken to ensure that the screw for the fourth metatarsal bone did not interpose with the fifth extensor tendon.

All cases achieved satisfactory lengthening and bony union, except 1 case. The healing index increased with patient's age. Plantar capsular release was performed in seven cases, six of which had been previously operated on bilaterally. There was no hindfoot varus deformity or entrapment of the fifth extensor tendon on final follow up.

Varus deformity of the hindfoot can be prevented by horizontal distraction of the first metatarsal bone. Also, entrapment of the fifth extensor tendon can be prevented by careful handling of the fifth extensor tendon during operation on the 4th metatarsal bone. Complications of stiffness or of an increase in treatment period were mainly found in bilaterally operated or relatively old (over 20 year-old) patients.