Computer-aided modification of Reverdin osteotomy template for hallux valgus / 中华创伤骨科杂志

ABSTRACT

Objective To provide a method to modify accurately the Reverdin osteotomy template for hallux valgus using 3D reconstruction and printing.Methods From June 2015 to June 2016,11 patients (16 feet) with hallux valgus at our departments underwent weight-bearing X-ray examination and continuous spiral CT scanning of the feet.The outer turning angle of hallux averaged 33.50° ± 6.80°,the first intermetatarsal angle 12.20°± 2.90° and the distal metatarsal articular angle 15.20°± 2.60°.Their imaging Dicom data were imported into Materialise Mimics Innovation Suite v16.0 software for generation of 3D models of the pelvis which were then stored in stereolithography format and imported into Imageware 12 software.After optimal templates were reversely rebuilt to have the best angles and range for Reverdin osteotomy in the 3D models,they were manufactured by a rapid prototyping machine.The osteotomy templates were used in surgery to guide the osteotomy of hallux valgus.Correction of hallux valgus,bone union at the osteotomy sites and weight-bearing walk were observed postoperatively.Results Accurate angles of osteotomy were confirmed by postoperative radiography in all the 16 feet.Follow-ups for 6 to 12 months showed in the 16 feet a mean outer turning angle of hallux of 7.31 °±0.33° (from 5° to 11 °) and a mean correction of 21.92°± 4.8° (from 13° to 24°).Bone union was fine at the osteotomy sites and no pain was reported during weight-bearing walk.Conclusion 3D reconstruction and printing can produce a patient-specific template for accurate Reverdin osteotomy for hallux valgus,leading to increased contact area and fine union of the osteotomy ends.