Multi-dimentional Correction of the Scarf Osteotomy for the Treatment of Hallux Valgus

무지 외반증에 시행한 Scarf 절골술의 3차원적 변형 교정력에 관한 연구

Purpose: Scarf osteotomy can provide the simultaneous correction of the hallux valgus angle (HVA), 1-2 intermetatarsal angle ($IMA_{1-2}$), DMAA and the plantar displacement of the fragment. The study was conducted to understand the multi-dimensional correction of the hallux valgus. Materials and Methods: Fourty eight patients who had undergone Scarf osteotomy with hallux valgus at more than $30^{\circ}$ of HVA and more than $15^{\circ}$ of $IMA_{1-2}$ were studied. Before an osteotomy, a reference K-wire was inserted to the 1st metatarsal head. After the osteotomy, the plantar fragment was moved laterally and the proximal end of the fragment was forced beyond the distal end which resulted in an internal rotation of the head fragment to correct the DMAA. Results: The HVA improved an average of $33.3^{\circ}$ to $7.7^{\circ}$ with the IMA1-2 respectively from $15.4^{\circ}$ to $6.5^{\circ}$. The DMAA improved an average of $19.5^{\circ}$ ($5.2-30.9^{\circ}$) to $4.5^{\circ}$ ($0.4-13.8^{\circ}$). By checking the angle, which was at an average of $25^{\circ}$ between the plantar surface of the foot and the osteotomy plane, the average distance of 1.9 mm (1.18-3.1 mm) of plantar displacement was measured using the value of sine (sin 25 = 0.422). Conclusions: It is possible to correct the HVA, IMA1-2 and DMAA simultaneously with one osteotomy making the lateral shift, the internal rotation and the plantar displacement of the plantar head fragment as desired. Despite the technicality and difficulty of the Scarf osteotomy, once familiarized through myriad procedures, all disadvantages are outweighed by the success and satisfaction of both patient and surgeon.