ObjectiveTo study the classification criteria of adult cuboid fracture and its guidance feasibility and effect of treatment. MethodsA retrospective analysis was made on the clinical data of 415 adult patients (416 feet) with cuboid fractures who had complete CT data treated between May 2009 and April 2014. There were 337 males and 78 females, aged 19 to 64 years (mean, 38.8 years). The left foot, right foot, and bilateral feet were involved in 220 cases, 194 cases, and 1 case respectively. The causes of injury were sprain in 106 cases, traffic accident in 65 cases, falling from height in 129 cases, and heavy crushing in 115 cases. The interval of injury and hospitalization was 2 hours to 3 days (mean, 8.5 hours). Based on CT findings, the classification criteria of cuboid fracture was proposed and methods of treatment was statistically analyzed. The external fixation surgery was performed in patients of type I (285 feet), type IIa (18 feet), and type III (5 feet); open reduction and internal fixation were performed in patients of type IIb (41 feet) and type III (67 feet), and bone grafting was used to repair defects in 58 feet (type III). ResultsAll patients were followed up 1 year to 5 years and 11 months (mean, 2 years and 3 months). Primary healing of incision was obtained. In patients with type I fracture, fracture healed in 165 feet at 4-6 weeks (mean, 5.5 weeks), fracture did not heal in the other 120 feet; the American Orthopaedic Foot and Ankle Society (AOFAS) score was 95-100(mean, 96.7) at last follow-up. In patients with type II fracture, fracture healed in all feet at 6-8 weeks (mean, 6.5 weeks); the AOFAS score was 92-100(mean, 95.5) at last follow-up. In patients with type III fracture, malunion was observed at 6-8 weeks in 5 feet undergoing external fixation, and in 9 feet undergoing open reduction and internal fixation with foot lateral column shortening, forefoot abduction deformity, osteoarthritis, lateral foot pain; fracture healed at 8-12 weeks in 58 feet undergoing open reduction and internal fixation, without osteoarthritis, cuboid bone shortening, and pain at cuboid bone; and AOFAS score was 75-97(mean,93.5) at last follow-up. ConclusionThe classification criteria of cuboid fracture proposed based on CT examination is feasible and has guiding significance to the choice of treatment method.
ObjectiveTo design a new type of transarticular cuboid bone plate by measuring and collecting the anatomic data of the articular surface around cuboid, and to carry out comparative biomechanical study. MethodsThe angle α (between the fifth metatarsocuboid joint and the fifth metatarsal bone) and the angle β (between the fifth metatarsocuboid joint and the calcaneocuboid joint) were measured in 100 adults on medial oblique X-ray film and 30 adult foot specimens. Based on literature data, the transarticular cuboid bone plate was designed with an angle α of 70° and an angle β of 30°. Six adult cadaver feet were chosen and were transected approximately 15 cm proximal to the ankle. Five strain gauges were placed at the calcaneus, cuboid, and the fourth and fifth metatarsal bones. The vertical pressure was loaded on the foot at 0-600 N, the strain value was measured. Then the cuboid fracture model was established and 600 N load was given on foot to measure the strain value and compare with the strain value before fracture. The specimens were randomly divided into groups A and B (n=3). Fracture was fixed with transarticular cuboid bone plate and 9 screws in group A and with double plate and 8 screws in group B, then the 600 N load was given to measure the strain value and vertical displacement of the fracture fragments. ResultsAfter loads of 0-600 N on the foot, the strain value of the 5 points showed an increased trend. No significant difference was found in the strain value between pre- and post-fracture at a, d, and e points P>0.05), but it was significantly larger at post-fracture than pre-fracture at b and c points (P<0.05). After fracture fixation, no significant difference was shown in the strain value at 5 points between groups A and B when loads of 0-600 N was given P>0.05). The experimental data showed that the strain value change mainly focused on the fracture site under the same load, so the strain value after fracture fixation was similar to that before fracture at b and c points P>0.05). The vertical displacement values of medial and lateral fracture fragments in group A[(0.804±0.011) mm and (0.672±0.036) mm] were significantly less than those in group B[(1.126±0.083) mm and (1.007±1.103) mm] (t=-6.711, P=0.003; t=-5.307, P=0.006). ConclusionThrough biomechanical study, a new type of transarticular cuboid bone plate has better fixation effect.