Yahya Deniz, Ece Davutluoglu, Mete Özer, Christopher W DiGiovanni, Soheil Ashkani-Esfahani, Bedri Karaismailoglu
In patient-specific computational models of rigid pes cavus reconstructed from weight-bearing CT images, first metatarsal dorsiflexion osteotomy was associated with predictable and quantifiable structural realignment. The relationship between wedge size and simulated angular correction was quantified using regression equations, which may provide a basis for individualized preoperative planning. However, the clinical applicability of this approach requires prospective validation.
OBJECTIVE: This study aimed to quantify structural alignment changes produced by virtual first metatarsal dorsiflexion osteotomy in patient-specific three-dimensional models reconstructed from weight-bearing CT images of rigid pes cavus and to establish regression models for preoperative planning.
METHODS: Three-dimensional models were generated from weight-bearing CT scans of ten patients with rigid pes cavus. Virtual first metatarsal dorsiflexion osteotomies were performed at 1 cm and 2 cm distal to the first tarsometatarsal joint using dorsal closing wedges of 3 mm, 5 mm, and 7 mm. Meary's angle (MA), calcaneal pitch angle (CPA), and Ground-Referenced Hindfoot Alignment Angle (GRHAA) were measured before and after each simulated osteotomy. Clinical validation was performed in five surgical cases by determining the required osteotomy wedge size using the regression equation for MA correction. Postoperative MA was evaluated relative to the targeted neutral alignment, and actual postoperative CPA was compared with the value predicted from the regression model.
RESULTS: At the 1 cm level, MA decreased by 6.6°, 10.9°, and 15.1°; CPA by 2.1°, 3.6°, and 4.9°; and GRHAA by 4.9°, 8.3°, and 11.6° for 3-, 5-, and 7 mm wedges, respectively. Corresponding decreases at the 2 cm level were 6.6°, 10.6°, and 14.3° for MA; 2.1°, 3.3°, and 4.5° for CPA; and 4.8°, 7.8°, and 10.7° for GRHAA. In the clinical validation cohort, the mean postoperative deviation from the targeted neutral MA was 1.4°, while the mean deviation between predicted and actual postoperative CPA was 1.8°.
CONCLUSION: In patient-specific computational models of rigid pes cavus reconstructed from weight-bearing CT images, first metatarsal dorsiflexion osteotomy was associated with predictable and quantifiable structural realignment. The relationship between wedge size and simulated angular correction was quantified using regression equations, which may provide a basis for individualized preoperative planning. However, the clinical applicability of this approach requires prospective validation.