Background:Although it has been established that adolescent idiopathic cervical kyphosis (AICK) has no known cause, there are associated risk factors. However, the underlying causes remain puzzling. This case report presents severe AICK linked to chronic neck flexion postural habit, treated with combined anterior and posterior correction surgery and review of the literature.Case presentation: A 16-year-old male with no history of trauma, surgery, or family history of spinal deformity complained of intolerable neck pain and rigidity. He developed an incessant reading of comic books at a very young age, and he preferred placing the book on the floor with his head flexed between his thighs. Acupuncture and massage therapy failed to relief symptoms. He had no neurological symptoms on examination and X-ray showed Cobb angle of 70.5 . MRI and CT scans showed no spinal cord compression or osteophyte formation. A combined anterior and posterior correction surgery was performed after a week of skull traction. The deformity was corrected, neck pain disappeared, and neck rotatory function maintained after posterior implant removal. The maximum follow-up was 10 years. Conclusions:The potential underlying risk factor observed in this case is unusual. Chronic neck flexion postural habit is a potential risk factor of severe AICK in some individuals.

No abstract

Objective. A magnetic resonance neurography (MRN) study was conducted to assess the neurological safety of endoscopic transforaminal lumbar intervertebral fusion (endo-TLIF). Materials and Methods. A total of 56 healthy volunteers (29 men, 27 women; average age, 44 yr; age range, 21-60 yr) were included in the study. Coronal MRN images were collected from L2/L3 to L5/S1. The working triangle, modified working zone, and safest working zone areas, as well as the vertical and horizontal safe operation diameters, were measured. Linear regression analyses were conducted to explore the correlations between general characteristics (sex, age, height, body mass index) and the measured radiographic indicators. Results. MRN can effectively evaluate the operation zone of endo-TLIF. The safest working zone, modified working zone, and working triangle areas were largest at L4/L5 (92.4 ± 23.4, 136 ± 35.6, and 197 ± 41.7 mm 2 , respectively) and smallest at L2/L3 (45.5 ± 12.9, 68.1 ± 19.5, and 92.6 ± 24.4 mm 2 , respectively). The vertical safe operation diameter was large at L4/L5 and L2/L3 (5.34 ± 0.8 and 5.42 ± 0.9 mm, respectively) and smallest at L5/S1 (2.94 ± 0.9 mm). The horizontal safe operation diameter was large at L4/L5 (7.28 ± 1.2 mm) and smaller at L5/S1 and L2/L3 (4.28 ± 1.0 and 4.77 ± 0.8 mm, respectively). Conclusions. L4/L5 has the lowest risk of nerve injury, and may be the safest level for beginners initiating endo-TLIF in their practice. We recommend that coronal MRN is routinely performed before endo-TLIF to minimize the risk of neurological injury.

Background: Percutaneous vertebroplasty is the most common treatment for osteoporotic vertebral compression fracture. However, the morbidity of vertebroplasty-related complications, such as cement leakage, remains high. We tested a new technique of unilateral pulsed jet lavage and investigated its effect on the intravertebral pressure and bone cement distribution.Methods: Thirty lumbar vertebrae (L1-L5) from six cadaver spines were randomly allocated into two groups (with and without irrigation). Prior to vertebroplasty, pulsed jet lavage was performed through one side of the pedicle by using a novel cannula with two concentric conduits to remove the fat and bone marrow of the vertebral bodies in the group with irrigation. The control group was not irrigated. Then, standardized vertebroplasty was performed in the vertebral bodies in both groups. Changes in the intravertebral pressure during injection were recorded. Computed tomography (CT) was performed to observe the cement distribution and extravasations, and the cement mass volume (CMV) was calculated. Results: During cement injection, the average maximum intravertebral pressure of the unirrigated group was higher than that of the irrigated group (4.92kPa versus 2.22kPa, P<0.05). CT scans showed a more homogeneous cement distribution with less CMV (3832 mm3 vs. 4344 mm3, P<0.05) and less leakage rate (6.7% vs. 46.7%, P<0.05) in the irrigated group than in the control group. Conclusions: Unilateral pulsed jet lavage can reduce intravertebral pressure and lower the incidence of cement leakage during vertebroplasty. An enhanced bone cement distribution can also be achieved through this lavage system.

Background: Percutaneous vertebroplasty is the most common treatment for osteoporotic vertebral compression fracture. However, the morbidity of vertebroplasty-related complications, such as cement leakage, remains high. We tested a new technique of unilateral pulsed jet lavage and investigated its effect on the intravertebral pressure and bone cement distribution.Methods: Thirty lumbar vertebrae (L1-L5) from six cadaver spines were randomly allocated into two groups (with and without irrigation). Prior to vertebroplasty, pulsed jet lavage was performed through one side of the pedicle by using a novel cannula with two concentric conduits to remove the fat and bone marrow of the vertebral bodies in the group with irrigation. The control group was not irrigated.Then, standardized vertebroplasty was performed in the vertebral bodies in both groups. Changes in the intravertebral pressure during injection were recorded. Computed tomography (CT) was performed to observe the cement distribution and extravasations, and the cement mass volume (CMV) was calculated.Results: During cement injection, the average maximum intravertebral pressure of the unirrigated group was higher than that of the irrigated group (4.92kPa versus 2.22kPa, P<0.05). CT scans showed a more homogeneous cement distribution with less CMV (3832 mm 3 vs. 4344 mm 3 , P<0.05) and less leakage rate (6.7% vs. 46.7%, P<0.05) in the irrigated group than in the control group.Conclusions: Unilateral pulsed jet lavage can reduce intravertebral pressure and lower the incidence of cement leakage during vertebroplasty. An enhanced bone cement distribution can also be achieved through this lavage system. BackgroundPercutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) is effective in the treatment of osteoporotic vertebral compression fractures. These techniques can provide instant pain relief [1][2][3] and stabilize vertebral fracture [3][4][5] . However, leakage during PVP or PKP remains a concern among surgeons. Some studies have shown that intravertebral lavage prior to cement injection can effectively remove vertebral fat and bone marrow and reduce the morbidity of extravasation [6,7] .Previously reported lavage methods involved bilateral operation [8,9,10] , but unilateral pulsed jet *Significant difference Leakage rateCement leakage was evaluated on the basis of the CT images. Cement leakage occurred in one (6.7%) of the irrigated specimens and in seven (46.7%) of the unirrigated ones (Table 1). Cement distributionCT images showed the distinct distributions of cement in the two groups. The bone cement mass was homogeneous and had more uniform density in the irrigated group than in the unirrigated group. The cement distribution of the unirrigated vertebrae was more irregular than that of the irrigated group (Fig.2). CMVThe Mann-Whitney U test results revealed smaller CMV in the irrigated group than in the unirrigated JY performed the experiments and participated in the design of the study. QL performed the experiments and wrote the manuscript. ZL, ...