Clinical study of a new design multifunction dynamic external fixator system for bone reconstructions.

Background: Fractures with related problems including intercalary bone defect, shortening, and malunion are still major problems in orthopedic practice. The Ilizalov's circular external fixator device has several advantages for bone reconstruction but also has certain drawbacks such as its bulkiness and complicated mounting. To maintain the advantages of Ilizalov's original concept and combine with the simplicity of monolateral frame, a new design multifunction dynamic external fixator system was developed to overcome the drawbacks.

Objective: To evaluate the clinical results and complications of a new design multifunction dynamic external fixator system for bone reconstructions.

Methods: Twenty patients requiring reconstructions between 2006 and 2009 participated in this study. The new design multifunction dynamic external fixators were used in 11 tibial and two femoral intercalary defects for bone transportation, three tibial and one femoral lengthening, and three tibial malunion correction (45, 60 and 75 degrees).

Results: In bone transportation, new bone formation and union at the docking site were achieved in all patients. The mean new bone formation was 5.8 cm (range 3.5-14) in tibia and 4.3 cm (range 3.5-5) in femur. The mean healing index was 46.3 days/cm (range 42-60) in tibia and 93.9 days/cm (range 85.7-102) in femur. In bone lengthening, new bone formation and union were achieved in all patients. The mean amount of elongation was 3.5 cm (range 3-4) in tibia and 5 cm in femur. The mean healing index was 71.1 days/cm (range 68.6-76) in tibia and 73 days/cm in femur. In malunion correction, the mean correction time was 65 days (range 35-84) and the mean healing time was 187.3 days (range 154-212).

Conclusions: The new design multifunction dynamic external fixator system was successfully used for bone transportation, bone lengthening, and malunion correction with good results and low complications. It is simple, safe, and easy to use.