Computational simulation study on ilio-sacral screw fixations for pelvic ring injuries and implications in Asian sacrum.

OBJECTIVES: Despite a high possibility of technique-related complications, ilio-sacral (IS) screw fixation is the mainstay of operative management in posterior pelvic ring injuries. We aimed to make IS screw trajectory with fully intraosseous path that was optimal and consistent, and confirm the possibility of transiliac-transsacral (TITS) screw fixation in Asian sacrum. METHODS: Eighty-two cadaveric sacra (42 males and 40 females) were enrolled and underwent continuous 1.0-mm slice computed tomography (CT) scans. CT images were imported into Mimics® software to reconstruct three-dimensional model of the pelvis. To simulate IS screws, we inserted 7.0-mm-sized TITS cylinder for first (S1) and second (S2) sacral segment and 7.0-mm oblique cylinder for S1. TITS cylinder could not be inserted into S1 of 14 models (sacral variation models) but could be inserted into the S2 of all models. The actual length of virtual IS screws was measured, and anatomic features of safe zone (SZS2) including the area, horizontal distance (HDS2), and vertical distance (VDS2) were evaluated by the possibility of TITS screw fixation in the S1. RESULTS: When the oblique cylinder was directed toward the opposite upper corner of S1 at the level of the first foramen, there was no cortical violation regardless of sacral variation. The average length of TITS cylinder was 152.3 mm (range 127.9-178.2 mm) in S1 and 136.0 mm (range 97.8-164.1 mm) in S2, and for oblique cylinder it was 99.2 mm (range 82.4-132.2 mm). The average VDS2, HDS2, and the area of SZS2 were 15.5 mm (range 8.7-24.4 mm), 18.3 mm (range 12.7-26.6 mm), and 221.1 mm2 (range 91.1-386.7 mm2), respectively. The VDS2 and SZS2 of sacral variation were significantly higher than those of normal (both p = 0.001). CONCLUSIONS: Considering the high variability of the S1, it is better to direct the IS screw trajectory toward the opposite upper corner of the S1 at the level of first sacral foramen. If a TITS screw is needed, the transverse fixation for the S2 could be performed alternatively due to its sufficient osseous site even in Asian sacrum.

Can the possibility of transverse iliosacral screw fixation for first sacral segment be predicted preoperatively? Results of a computational cadaveric study.

OBJECTIVES: The purpose of this study was to predict the possibility of transverse iliosacral (TIS) screw fixation into the first sacral segment (S1) and introduce practical anatomical variables using conventional computed tomography (CT) scans. MATERIALS AND METHODS: A total of 82 cadaveric sacra (42 males and 40 females) were used for continuous 1.0-mm slice CT scans, which were imported into Mimics® software to produce a three-dimensional pelvis model. The anterior height (BH) and superior width (BW) of the elevated sacral segment was measured, followed by verification of the safe zone (SZS1 and SZS2) in a true lateral view. Their vertical (VDS1 and VDS2) and horizontal (HDS1 and HDS2) distances were measured. VDS1 less than 7mm was classified as impossible sacrum, since the transverse fixation of 7.0 mm-sized IS screw could not be done safely. RESULTS: Fourteen models (16.7%; six females, eight males) were assigned as the impossible sacrum. There was no statistical significance regarding gender (p=0.626) and height (p=0.419). The average values were as follows: BW, 31.4mm (SD 2.9); BH, 16.7mm (SD 6.8); VDS1, 13.4mm (SD 6.1); HDS1, 22.5mm (SD 4.5); SZS1, 239.5mm2 (SD 137.1); VDS2, 15.5mm (SD 3.0); HDS2, 18.3mm (SD 2.9); and SZS2, 221.1mm2 (SD 68.5). Logistic regression analysis identified BH (p=0.001) and HDS1 (p=0.02) as the only statistically significant variables to predict the possibility. Receiver operating characteristic curve analysis established a cut-off value for BH and HDS1 of impossible sacrum of 20.6mm and 18.6mm, respectively. CONCLUSION: BH and HDS1 could be used to predict the possibility of TIS screw fixation. If the BH exceeds 20.6mm or HDS1 is less than 18.6mm, TIS screw fixation for S1 should not be undertaken because of narrowed SZ.

Biocementation of Concrete Pavements Using Microbially Induced Calcite Precipitation.

In this study, the feasibility of introducing calcite-forming bacteria into concrete pavements to improve their mechanical performance was investigated. Lysinibacillus sphaericus WJ-8, which was isolated in a previous study and is capable of exhibiting high urease activity and calcite production, was used. When analyzed via scanning electron microscopy (SEM) and X-ray diffraction, WJ-8 showed a significant amount of calcite precipitation. The compressive strength of cement mortar mixed with WJ-8 cells and nutrient medium (urea with calcium lactate) increased by 10% compared with that of the controls. Energy dispersive x-ray spectroscopy analyses confirmed that the increase in strength was due to the calcite formed by the WJ-8 cells.

Apigenin Regulates Interleukin-1ß-Induced Production of Matrix Metalloproteinase Both in the Knee Joint of Rat and in Primary Cultured Articular Chondrocytes.

We examined whether apigenin affects the gene expression, secretion and activity of matrix metalloproteinase-3 (MMP-3) in primary cultured rabbit articular chondrocytes, as well as in vivo production of MMP-3 in the knee joint of rat to evaluate the potential chondroprotective effects of apigenin. Rabbit articular chondrocytes were cultured in a monolayer, and reverse transcription - polymerase chain reaction (RT-PCR) was used to measure interleukin-1ß (IL-1ß)-induced expression of MMP-3, MMP-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), and ADAMTS-5. In rabbit articular chondrocytes, the effects of apigenin on IL-1ß-induced secretion and proteolytic activity of MMP-3 were investigated using western blot analysis and casein zymography, respectively. The effect of apigenin on MMP-3 protein production was also examined in vivo. In rabbit articular chondrocytes, apigenin inhibited the gene expression of MMP-3, MMP-1, MMP-13, ADAMTS-4, and ADAMTS-5. Furthermore, apigenin inhibited the secretion and proteolytic activity of MMP-3 in vitro, and inhibited production of MMP-3 protein in vivo. These results suggest that apigenin can regulate the gene expression, secretion, and activity of MMP-3, by directly acting on articular chondrocytes.

Chondroprotective Effects of Wogonin in Experimental Models of Osteoarthritis in vitro and in vivo.

We evaluated the chondroprotective effects of wogonin by investigating its effects on the gene expression and production of matrix metalloproteinase-3 (MMP-3) in primary cultured rabbit articular chondrocytes, as well as on production of MMP-3 in the rat knee. Rabbit articular chondrocytes were cultured in a monolayer, and RT-PCR was used to measure interleukin-1ß (IL-1ß)-induced expression of MMP-3, MMP-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), and type II collagen. In rabbit articular chondrocytes, the effects of wogonin on IL-1ß-induced production and proteolytic activity of MMP-3 were investigated using western blot analysis and casein zymography, respectively. The effect of wogonin on MMP-3 protein production was also examined in vivo. In rabbit articular chondrocytes, wogonin inhibited the expression of MMP-3, MMP-1, MMP-13, and ADAMTS-4, but increased expression of type II collagen. Furthermore, wogonin inhibited the production and proteolytic activity of MMP-3 in vitro, and inhibited production of MMP-3 protein in vivo. These results suggest that wogonin can regulate the gene expression and production of MMP-3, by directly acting on articular chondrocytes.

Systematic review of cadaveric studies on anatomic posterior cruciate ligament reconstruction: the landmarks in anatomic posterior cruciate ligament reconstruction.

Recently, several new techniques for anatomic posterior cruciate ligament reconstruction (PCLR) have emerged and are believed to restore the normal anatomy of the posterior cruciate ligament more accurately. Despite the latest trend, the optimal methods for anatomic PCLR remain controversial. The purpose of this research is to review surgical techniques for PCLR in cadaver studies and suggest consistent and reproducible technical criteria. For the review of the literature, MEDLINE and EMBASE were screened for articles on anatomic PCLR. Only basic science studies on PCLR performed on human cadavers and written in English were included. Seventeen studies were included in this systematic review. Only the tunnel positions, graft types, and surgical techniques were reported in the majority of the studies. There were many variations of the reported tunnel positions, graft types, and surgical techniques among the studies. In most studies, surgical techniques for consistent and reproducible anatomic PCLR were not explained clearly. Therefore, high level medical research should be encouraged in order to establish standard surgical techniques for anatomic PCLR.

Monostotic fibrous dysplasia in the proximal tibial epiphysis: a case report.

INTRODUCTION: Fibrous dysplasia is one of many well-known disorders in which there is a defect in the remodeling process of immature bone to mature into lamellar bone, and it often exists in metaphyseal and diaphyseal parts of the long bone. In this report, we describe a rare case where fibrous dysplasia was found only in the proximal part of the epiphysis of the tibia without other bony lesions. CASE PRESENTATION: A 14-year-old Asian girl was referred to our hospital after slipping down with pain on the left knee. A radiograph showed an abnormal finding of a central radiolucent lesion with a marginal sclerotic border near the proximal tibial spine. A magnetic resonance image showed the lesion at low signal intensity on a T1-weighted image and at high signal intensity on a T2-weighted image. The biopsy results led us to conclude that the lesion was a fibrous dysplasia. CONCLUSION: If an abnormal lesion on the epiphysis, especially in long bones, is detected on a radiograph, several differential diagnoses can be made. Although fibrous dysplasia is usually not encountered as an epiphyseal lesion, it is important to incorporate all the clinical, radiographic and pathologic features to diagnose monostotic fibrous dysplasia when the lesion is located at the epiphyseal location.