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.
ObjectiveTo observe the effectiveness of 360° internal fixation by anteromedial and posterior-lateral approaches for high-energy closed Pilon fractures. MethodsBetween February 2013 and February 2015, 18 cases of high-energy closed Pilon fractures were treated. There were 11 males and 7 females with an average age of 40.5 years (range, 20-65 years). The causes were falling injury in 10 cases and traffic accident injury in 8 cases. All fractures were RüediAllgower type Ⅲ Pilon fracture combined with ipsilateral fibula fracture. The average interval from injury to operation was 8 days (range, 5-13 days). Reduction of fracture was performed by anteromedial and posterior-lateral approaches and the fracture fragments were fixed by 360° internal fixation. The effectiveness was assessed by ankle X-ray film and Mazur score at last follow-up. ResultsTwo cases had skin necrosis and received flap surgery, the other cases obtained primary healing of incision. All the cases were followed up 11.2 months on average (range, 3-27 months). X-ray film showed that all fractures healed at 3-4 months after operation (mean, 3.6 months). No deep infection or plate exposure occurred. According to Mazur score, the results were excellent in 8 cases, good in 7 cases, fair in 2 cases, and poor in 1 case, and the excellent and good rate was 83.3%. ConclusionThe effectiveness of the 360° internal fixation for treatment of high-energy closed Pilon fractures has the advantages of reliable fixation, early functional exercise, and good functional recovery of the ankle joint.
ObjectiveTo observe the characteristics of acetabular labrum injury in Pipkin fractures and the effectiveness of repairing the labrum with suture anchor. MethodsBetween July 2010 and July 2013, 10 cases of Pipkin fractures accompanied by acetabular labrum injury were treated. There were 7 males and 3 females with an average age of 32.5 years (range, 24-56 years). The causes of injury included traffic accident in 8 cases and falling from height in 2 cases. According to the Pipkin classification criteria, there were 6 cases of type Ⅱ, 2 cases of type Ⅲ, and 2 cases of type Ⅳ. The average interval from injury to operation was 8 days (range, 6-14 days). All the patients underwent open reduction and internal fixation through transtrochanteric approach with trochanteric osteotomy, and repair the labrum with suture anchor. The effectiveness was evaluated according to the Thompson & Epstein scoring scales after operation. ResultsAll incisions healed primarily without early complication of deep infection or deep vein thrombosis of lower limb. All the cases were followed up 22 months on average (range, 12-48 months). X-ray films showed that all osteotomies and acetabular fractures healed within 3-4 months, femoral head and femoral neck fracture healed within 6-11 months. MRI examinations showed that all repaired acetabular labrums well healed. One case had necrosis of the femoral head at 12 months after operation, and was treated by total hip arthroplasty. According to the Thompson & Epstein scoring scales at last follow-up, the results were excellent in 5 cases, good in 3 cases, fair in 1 case and poor in 1 case, with an excellent and good rate of 80%. ConclusionThe diagnosis of acetabular labrum injury can be easily missed during Pipkin fracture, preoperative diagnosis should be combined with hip MRI. Trochanteric osteotomy through transtrochanteric approach, and repairing the labrum with suture anchor can restore the hip function effectively.