Postoperative accuracy analysis of three-dimensional corrective osteotomy for cubitus varus deformity with a custom-made surgical guide based on computer simulation.

BACKGROUND

For correction of cubitus varus deformity resulting from supracondylar fracture of the humerus, we developed an operative method with use of a custom-made surgical guide, designed on the basis of 3-dimensional (3D) computer simulation with computed tomography data. The purpose of this study was to investigate the postoperative accuracy of this system in clinical cases.

METHODS

Subjects included 17 consecutive patients (13 males and 4 females) with cubitus varus deformity after supracondylar fracture. Patients underwent 3D corrective osteotomy with use of a custom-made surgical guide. Postoperative computed tomography scan was performed after bone union diagnosis on plain radiographs, and postoperative 3D bone models were compared with preoperative simulation by surface registration technique. In addition, we evaluated radiographic parameters (humerus-elbow-wrist angle and tilting angle) and range of elbow motion at the most recent follow-up.

RESULTS

Mean errors in 3D corrective osteotomy were 0.6° ± 0.7° in varus-valgus rotation, 0.8° ± 1.3° in flexion-extension rotation, 2.9° ± 2.8° in internal-external rotation, 1.7 ± 1.8 mm in anterior-posterior translation, 1.3 ± 1.8 mm in lateral-medial translation, and 7.1 ± 6.3 mm in proximal-distal translation. The mean humerus-elbow-wrist angle on plain radiographs of the affected side was 15° in varus before surgery and improved to 6° in valgus after surgery. The mean tilting angle of the affected side was 31° before surgery and improved to 40° after surgery.

CONCLUSION

The 3D correction of cubitus varus deformity was performed accurately within the allowable error limits.