Distal femoral osteotomy: is internal fixation better than external?

Distal femoral osteotomies (DFO) can be used to correct deformities around the knee. Although osteotomies can be fixed with either internal or external fixation techniques, the advantages of one over the other are unclear.

We asked whether (1) for both techniques, we could accurately correct the deformities based on our preoperative goals for mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA), and (2) intraoperative times, (3) preoperative and postoperative knee ROM, and (4) complications differed.

We identified 26 patients (34 limbs) who underwent femoral osteotomies. We compared accuracy of correction (based on correction of the MAD and the LDFA), duration of surgery, preoperative and postoperative knee ROM, and complications. The minimum followup was 20 months (mean, 29 months; range, 20-40 months).

We achieved the desired MAD within 10 mm of the goal in 18 of 21 limbs with the unilateral frame and in 12 of 13 limbs using fixator-assisted plating. Operative time for fixator-assisted plating was longer (122 ± 34 minutes) than when using a unilateral frame (94 ± 65 minutes). Preoperative and postoperative knee ROMs were similar for both techniques and there were no major complications.

We obtained accurate correction of deformities with both fixation techniques. Our experience suggests the method to be used should be left to the discretion of the surgeon and the needs and wishes of the patient after adequate explanation of the advantages and disadvantages.

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.