Complicated Bosworth fracture-dislocation: A case report and review of the literature.

Bosworth fracture and dislocation is relatively rare, accounting for about 1% of ankle fractures. It is characterized by the proximal fibula fracture embedded in the posterolateral distal tibia. Due to an insufficient understanding of this fracture, it is easy to cause missed diagnosis and misdiagnosis in clinical practice. Due to the insertion of the fracture, it is challenging to perform closed reduction, and improper treatment is easy to cause complications. Surgical treatment is recommended for this type of fracture. In order to improve the understanding of orthopedic surgeons about Bosworth fracture and dislocation, this paper reports the diagnosis and treatment of 2 cases of Bosworth fracture and dislocation, and reviews the literature on Bosworth fracture's mechanism, diagnosis, classification, complications, and treatment options in recent years.

Function-preserving reduction and fixation of unstable Jefferson fractures using a C1 posterior limited construct.

STUDY DESIGN: This is a retrospective, clinical, and radiologic study of posterior reduction and fusion of the C1 arch in the treatment of unstable Jefferson fractures. OBJECTIVE: The aim of the study was to describe a new motion-preserving surgical technique in the treatment of unstable Jefferson fracture. SUMMARY OF BACKGROUND DATA: The management of unstable Jefferson fractures remains controversial. The majority of C1 fractures can be effectively treated nonoperatively with external immobilization unless there is an injury to the transverse atlantal ligament (TAL). Conservative treatment usually involves immobilization for a long time in Halo vest, whereas surgical intervention generally involves C1-C2 fusion, eliminating the range of motion of the upper cervical spine. We propose a novel method for the treatment of unstable Jefferson fractures without restricting the range of motion. METHODS: A retrospective review of 12 patients with unstable C1 fractures between April 2008 and October 2011 was performed. They were treated by inserting bilateral posterior C1 pedicle screws or lateral mass screws interconnected by a transversal rod to achieve internal fixation. There were 8 men and 4 women, with an average age of 35.6 years (range, 20-60 y). Presenting symptoms included neck pain, stiffness, and decreased range of motion but none had neurological injury. Seven patients had bilateral posterior arch fractures associated with unilateral anterior arch fractures (posterior 3/4 Jefferson fracture, Landells type II), and 5 had unilateral anterior and posterior arch fractures (half-ring Jefferson fracture, Landells type II). Seven patients had intact TAL, and 5 patients had fractures and avulsion of the attachment of TAL (Dickman type II). RESULTS: A total of 24 screws were inserted. Five cases had screws placed in the lateral mass: 3 because of posterior arch breakage, and 2 because the height of the posterior arch at the entry point was <4 mm. The remaining 7 cases had pedicle screw fixation. One patient had venous plexus injury during exposure of lower margin of the posterior arch; however, successful hemostasis was achieved with Gelfoam. Postoperative x-ray and computed tomography scan showed partial breach of the transverse foramen caused by a screw in 1 case, and breach of the inner cortex of the pedicle caused by screw displacement in 1 case; however, no spinal cord injury or vertebral artery injury was found. The remaining screws were in good position. Patients were followed up for 6-40 months (average, 22 mo). All cases had recovery of range of motion of the cervical spine to the preinjury level by 3-6 months after surgery, with resolution of pain. At 6 months follow-up, plain radiographs and computed tomography scans revealed satisfactory cervical alignment, no implant failure, and satisfactory bony fusion of the fractures; no C1-C2 instability was observed on the flexion-extension radiographs. CONCLUSIONS: C1 posterior limited construct is a valid technique and a feasible method for treating unstable Jefferson fractures, which allows preservation of the function of the craniocervical junction, without significant morbidity.

Modelling and assessing the effects of medical resources on transmission of novel coronavirus (COVID-19) in Wuhan, China.

The coronavirus disease 2019 (COVID-2019), a newly emerging disease in China, posed a public health emergency of China. Wuhan is the most serious affected city. Some measures have been taken to control the transmission of COVID-19. From Jan. 23rd, 2020, gradually increasing medical resources (such as health workforce, protective clothing, essential medicines) were sent to Wuhan from other provinces, and the government has established the hospitals to quarantine and treat infected individuals. Under the condition of sufficient medical resources in Wuhan, late-stage of epidemic showed a downward trend. Assessing the effectiveness of medical resources is of great significance for the future response to similar disease. Based on the transmission mechanisms of COVID-19 and epidemic characteristics of Wuhan, by using time-dependent rates for some parameters, we establish a dynamical model to reflect the changes of medical resources on transmission of COVID-19 in Wuhan. Our model is applied to simulate the reported data on cumulative and new confirmed cases in Wuhan from Jan. 23rd to Mar. 6th, 2020. We estimate the basic reproduction number R0 = 2.71, which determines whether the disease will eventually die out or not under the absence of effective control measures. Moreover, we calculate the effective daily reproduction ratio Re(t), which is used to measure the 'daily reproduction number'. We obtain that Re(t) drops less than 1 since Feb. 8th. Our results show that delayed opening the 'Fire God Hill' hospital will greatly increase the magnitude of the outbreak. This shows that the government's timely establishment of hospitals and effective quarantine via quick detection prevent a larger outbreak.

[Biomechanical application of finite element method in upper cervical spine].

Biomechanics plays an important role in the pathogenesis of upper cervical spine disease. Traditional biomechanical test, such as animal experiment, physical experiment and vitro experiment exists many problems. Finite element method, a new biomechanical method, can repeat in sustainability study, change quality and quantity, provide the manifestation of local and internal region and make up the deficiency of current methods. The paper summaries the biomechanical application of finite element method in upper cervical spine, including the finite element modeling, pathophysiological mechanism of upper cervical spine and biomechanical analysis of internal fixation devices.

[Clinical application of centerpiece titanium plate fixation in open door laminoplasty].

OBJECTIVE: To explore the clinical application of Centerpiece titanium plate fixation in open door laminoplasty. METHODS: From January 2009 to December 2010,25 patients with cervical spinal stenosis were treated by open door laminoplasty with Centerpiece titanium plate fixation. There were 16 males and 9 females,with a mean age of (57.2 +/- 6.7) years (ranged, 44 to75 years). There were multilevel cervical myelopathy in 8 cases, posterior longitudinal ligament ossification in 12 cases and congenital cervical spinal stenosis in 5 cases. According to Japanese Orthopedic Association (JOA) score to evaluate nerve function and calculate improvement rate. X-ray and CT were used to evaluate postoperative spinal canal enlargement and bone fusion at the hinge side. The sagittal diameter of C5 spinal canal on the lateral X-ray was measured before operation and 6 months after operation respectively, and the expansion rate of spinal canal was calculated [(postoperative sagittal diameter-preoperative sagittal diameter)/(preoperative sagittal diameter) x 100%]. RESULTS: The operative time and intraoperative blood loss were respectively (165.5 +/- 35.6) min and (325.0 +/- 75.1) ml. All patients were followed up from 6 to 18 months with an average of (7.3 +/- 3.8) months. The JOA score increased from 9.3 +/- 1.1 before operation to 14.7 +/- 2.1 at 6 months after operation (t = 4.12, P < 0.05), and the improvement rate was (64.5 +/- 10.2)%. Radiographic data showed spinal canal enlarged perfectly, bone fusion at hinge side and no cervical spinal stenosis was found. The sagittal diameter of C5 spinal canal improved from (9.0 +/- 1.5) mm before operation to (14.3 +/- 2.0) mm at 6 months after operation (t = 7.61, P < 0.05), and the expansion rate was (67.6 +/- 11.8)%. CONCLUSION: Clinical application of Centerpiece titanium plate fixation in open door laminoplasty is safe and effective. While vertebral plate is elevated to obtain instantly stability, at the same time, the integrity of spinal canal is also recovered.

[Study on the feasibility of posterior thoracic transarticular screw fixation].

OBJECTIVE: To study the feasibility and technical parameters of posterior transarticular screw fixation in the thoracic spine. METHODS: Since September 2009 to December 2009, 20 thoracic cadaveric spines (12 males and 8 females) were dissected. The lateral masses and pedicles were exposed carefully. After the entrance point of transarticular screws was determined, posterior transarticular screws implantation was performed under direct visualization into T(1,2), T(5,6) and T(9,10). Then CT scan was performed. On the CT scan,the angle and length of the transarticular screw trajectory were measured. RESULTS: The thoracic transarticular screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the coronal plane with successful placement. There was little differences between different segmental of thoracic vertebrae of the angle, but without significance (P > 0.5). The average angles of the screws were (52.6 +/- 5.9) degrees caudal tilting in the sagittal plane and (12.4 +/- 2.9)0 lateral tilting in the coronal plane. The average trajectory lengths were (22.5 +/- 1.9) mm. There was significant differences statistically among T(1,2), T(5,6) and T(9,10) (P < 0.01). CONCLUSION: Posterior transarticular screw fixation is feasible. Transarticular screw fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.