Minimally invasive injectable lumbar interbody fusion with mineralized collagen-modified PMMA bone cement: A new animal model.

This study was to develop a feasible and safe animal model for minimally invasive injectable lumbar interbody fusion using a novel biomaterial, mineralized collagen-polymethylmethacrylate bone cement (MC-PMMA), with unilateral pedicle screw fixation in an in vivo goat model. Eight goats (Capra aegagrus hircus) were divided into three groups: MC-PMMA, unmodified commercial-polymethylmethacrylate bone cement (UC-PMMA), and a control group (titanium cage filled with autogenous bone, TC-AB). Each group of goats was treated with minimally invasive lumbar interbody fusion at the L3/L4 and L5/L6 disc spaces (injected for MC-PMMA and UC-PMMA, implanted for TC-AB). The pedicle screws were inserted at the L3, L4, L5, and L6 vertebrae, respectively, and fixed on the left side. The characteristics of osteogenesis and bone growth were assessed at the third and the sixth month, respectively. The methods of evaluation included the survival of each animal, X-ray imaging, and 256-layer spiral computed tomography (256-CT) scanning, imaged with three-dimensional microfocus computed tomography (micro-CT), and histological analysis. The results showed that PMMA bone cement can be extruded smoothly after doping MC, the MC-PMMA integrates better with bone than the UC-PMMA, and all goats recovered after surgery without nerve damage. After 3 and 6 months, the implants were stable. New trabecular bone was observed in the TC-AB group. In the UC-PMMA group a thick fibrous capsule had formed around the implants. The MC-PMMA was observed to have perfect osteogenesis and bone ingrowth to adjacent bone surface. Minimally invasive injectable lumbar interbody fusion using MC-PMMA bone cement was shown to have profound clinical value, and the MC-PMMA showed potential application prospects.

Temporal small arterial inflammation is common in patients with giant cell arteritis.

Giant cell arteritis (GCA) primarily involves medium-to-large arteries. Small-vessel inflammation is a recognized phenomenon occurring in association with GCA. However, its significance is poorly elucidated. Histologic sections and medical records of105 temporal artery specimens were retrospectively reviewed between 2008 and 2017 to examine associated clinical manifestations and laboratory data including antinuclear antibody and p-antineutrophilic cytoplasmic antibody titers. Immunohistochemical staining for CD4 and CD8 was performed in select cases to assess the nature of the inflammatory response. Seventy-eight patients meeting the diagnostic criteria of temporal arteritis were included in the analysis. Twenty-eight specimens demonstrated temporal arteritis with small arterial inflammation (SAI), and 50 specimens showed temporal arteritis without SAI. Eight (28.6%) of 28 patients with SAI presented with jaw claudication, whereas 5 (17.9%) were febrile at presentation. In contrast, in 50 patients without SAI, jaw claudication and fever were seen in 11 and 2 cases, respectively (P = .01 and P = .0047, respectively). No statistically significant difference was noted between other symptoms and laboratory indices between the 2 groups. Elevated p-antineutrophilic cytoplasmic antibody titers in GCA may be associated with concomitant polymyalgia rheumatica or treatment-resistant disease. We also identified a higher count of CD4 and CD8 T cells in SAI cases, although the ratio of CD4/CD8 T lymphocytes was within normal limits. In conclusion, simultaneous involvement of arterioles and medium- to large-sized arteries is common in GCA and may be associated with treatment-refractory disease. Documentation of small arterial involvement in GCA will help the clinicians to manage the disease more effectively.