Minimally invasive treatment of calcaneal fractures via the sinus tarsi approach based on a 3D printing technique.

The sinus tarsi approach can be used for a limited exposure of the calcaneal fracture site. The reduction of the posterior articular surface, the shape of the calcaneus, the precise placement of the sustentacular screw (SS), the posterior articular surface screw of the calcaneal (PASS), and the long axis screw of the calcaneal (LAS) are still challenging. To that end, we proposed a minimally invasive technique for the treatment of calcaneal fractures via the sinus tarsi approach in combination with a three-dimensional (3D) printing technique. First, a 3D reconstructed model of the bilateral calcanei was obtained according to the computed tomography (CT) scan data and was used to simulate the placement of screws and acquire the screw trajectory parameters. Next, using 3D printing, a model of the calcaneus was printed, and the minimally invasive steel plate was pre-shaped to fit the lateral wall of the model. Finally, a total of 25 patients underwent this procedure. The results showed significant accuracy improvement in terms of the SS, PASS and LAS placement and in terms of the parameters including Bohler's angle, Gissane's angle, and the calcaneal width. In this work, the technique of the personalized minimally invasive treatment of calcaneal fractures improved the accuracy of screw placement (SP) and the reduction rate of posterior articular surface, improved the shape of the calcaneus, and increased the precision of the minimally invasive treatment of calcaneal fractures via the sinus tarsi approach.

[Experimental study on internal fixation with screws through femoral epiphyseal plate].

OBJECTIVE: To explore the effect of internal fixation with screw through femoral epiphyseal plate on growth in- hibition via an experimental study. METHODS: Forty New Zealand rabbits were randomly divided into 4 groups and 10 rabbits in each group. Epiphyseal plate was injured by penetrating of screws, and the size of damage area was controlled by changing the number of threads. Group A: blank group; group B: injury area accounted for 4% of the epiphyseal plate; group C: injury area accounted for 6%; group D: injury area accounted for 8%. The internal fixation was removed after 2 weeks, and the results were observed with X-ray film for 4 groups to judge the complications such as early closure of epiphyseal. RESULTS: In each group, there were no statistical differences in the length of the femoral neck, the diameter of femoral neck, the diameter of the femoral head, and the epiphyseal plate closure time. The growth speed of the length and diameter of the femoral neck, as well as the diameter of femoral head, were quicker on the early phase, and the speed was slowest when the epiphyseal plate was being closed. CONCLUSION: The injury area of epiphyseal plate under 8% is safe for its growth. Because no evidences demonstrate the growth inhibition of epiphyseal plate, the screws can be used for rabbit epiphyseal plates.

[Treatment of radial neck fracture in children with elastic stable intramedullary nails].

OBJECTIVE: To investigate effects of elastic stable intramedullary nails for the treatment of radial neck fracture in children. METHODS: From July 2006 to December 2011, 25 children with radical neck fractures, which included 16 males and 9 females aged from 7 to 15 years old (means 10.7), were treated with elastic stable intramedullary nails. According to Judet classification, 6 cases were type II, 17 cases were type III and 2 cases were type IV (including 1 case with type IVa and 1 case with type IVb). The fracture healing, pain, deformity and range of motion of elbow were recorded. RESULTS: All patients were followed up for 6 to 24 months with an average of 14 months. Twenty-five patients were obtained bone healing. According to Tibone and Stoltz evaluation standard, 18 cases got excellet results, 4 cases in good and 3 cases in moderate. CONCLUSION: Elastic stable intramedullary nails for the treatment of radial neck fracture in children has advantages of simple operation,less trauma and good results.

[Analysis on complications of elastic nail treating children's long bone fractures].

OBJECTIVE: To analyze the reasons on complications of treatment with elastic nail in children's long bone fracture. METHODS: Sixty-six cases (75 parts of long bone fratures) were treated by elastic nail including 49 male and 17 female. The age ranged from 3 to 17 years, mean 7.8 years. There were 35 femur fractures (2 cases were hibateral), 20 tibia and fibula fractures (12 cases were tibia fractures), 8 radial fractures (1 case was ulna fracture) and 3 humerus fractures. The cases included 4 open fractures and 62 closed fractures. All cases were fresh fractures, no multi-segmental fractures. Three cases associated with brain and chest injuries. These cases were treated by open or closed reduction and internal fixaion with elastic nail. A cast or brace had been used after operation for a month. Following-up included the function of the joint,the bottom of the nail and the callus. Complications were timely recorded. RESULTS: All the patients were followed-up for 12 to 29 months, averaged 17 months. The cases occurrenced compilications including 2 cases of nonunion, 2 of new fracture, 1 of displacment, 4 of joint dysfunction, 3 of irritation of the bottom of the nail and 1 malunion. CONCLUSION: Strict indication, well design,canonical operation is a good way to avoid compliacations. At the same time,early treatment can reduce the sequela.

[Distribution of hepatitis B virus genotype in 5 cities of Fujian province and the clinical implications of HBV genotype].

OBJECTIVE: To study the prevalence of hepatitis B virus (HBV) genotype in 5 cities of Fujian province and the clinical implications of distinct genotypes in HBV-related liver diseases. METHODS: HBV genotype was determined by the restriction fragment length polymorphism analysis in patients with chronic HBV infection in 5 cities of Fujian province. The relationship between HBV genotype and its clinical implications was studied by multinomal logistic regression and correspondence analysis. RESULTS: Of the 431 HBV DNA positive patients detected by PCR, 275 (63.8%) belonged to HBV genotype B, 100 (23.2%) to genotype C, 51 (11.8%) to genotype D and D-mixed genotype. Genotype A, E and F were not found. Multinomal logistic regression showed that genotype B was more prevalent in Quanzhou and Sanming cities than in Fuzhou (P = 0.002, P = 0.006), and genotype B appeared significantly more common in asymptomatic carriers (ASC), chronic hepatitis B (CHB) and severe hepatitis (SH). Genotype C was most prevalent in patients with liver cirrhosis (LC) (47.0%) than in those with ASC (14.5%) and SH (14.7%) (P = 0.009, P < 0.001). The positive rate of hepatitis B e antigen was higher in patients with genotype C than in those with genotype B and genotype D (56.0% vs. 52.4%, P = 0.008, and 56.0% vs. 30.8%, P = 0.051, respectively). By correspondence analysis, genotype D and D-mixed genotype seemed to be correlated with hepatocellular carcinoma (HCC). CONCLUSIONS: (1) The major popular genotypes of HBV were B, C and D in Fujian. (2) Data of our study suggested that the geographic distribution of genotype B and C might be different in some cities of Fujian. (3) Genotype B might have a tendency to lead to SH in younger patients with chronic hepatitis B and the development of LC might be associated with genotype C among the elder patients. (4) Genotype D appeared to associate with development of HCC, which called for further study to confirm.