Integration of statistical shape modeling and alternating interpolation-based model tracking technique for measuring knee kinematics in vivo using clinical interleaved bi-plane fluoroscopy.

Background: A 2D fluoroscopy/3D model-based registration with statistical shape modeling (SSM)-reconstructed subject-specific bone models will help reduce radiation exposure for 3D kinematic measurements of the knee using clinical alternating bi-plane fluoroscopy systems. The current study aimed to develop such an approach and evaluate in vivo its accuracy and identify the effects of the accuracy of SSM models on the kinematic measurements. Methods: An alternating interpolation-based model tracking (AIMT) approach with SSM-reconstructed subject-specific bone models was used for measuring 3D knee kinematics from dynamic alternating bi-plane fluoroscopy images. A two-phase optimization scheme was used to reconstruct subject-specific knee models from a CT-based SSM database of 60 knees using one, two, or three pairs of fluoroscopy images. Using the CT-reconstructed model as a benchmark, the performance of the AIMT with SSM-reconstructed models in measuring bone and joint kinematics during dynamic activity was evaluated in terms of mean target registration errors (mmTRE) for registered bone poses and the mean absolute differences (MAD) for each motion component of the joint poses. Results: The mmTRE of the femur and tibia for one image pair were significantly greater than those for two and three image pairs without significant differences between two and three image pairs. The MAD was 1.16 to 1.22° for rotations and 1.18 to 1.22 mm for translations using one image pair. The corresponding values for two and three image pairs were 0.75 to 0.89° and 0.75 to 0.79 mm; and 0.57 to 0.79° and 0.6 to 0.69 mm, respectively. The MAD values for one image pair were significantly greater than those for two and three image pairs without significant differences between two and three image pairs. Conclusions: An AIMT approach with SSM-reconstructed models was developed, enabling the registration of interleaved fluoroscopy images and SSM-reconstructed models from more than one asynchronous fluoroscopy image pair. This new approach had sub-millimeter and sub-degree measurement accuracy when using more than one image pair, comparable to the accuracy of CT-based methods. This approach will be helpful for future kinematic measurements of the knee with reduced radiation exposure using 3D fluoroscopy with clinically alternating bi-plane fluoroscopy systems.

Three-Dimensional Subject-Specific Knee Shape Reconstruction with Asynchronous Fluoroscopy Images Using Statistical Shape Modeling.

Background and objectives: Statistical shape modeling (SSM) based on computerized tomography (CT) datasets has enabled reasonably accurate reconstructions of subject-specific 3D bone morphology from one or two synchronous radiographs for clinical applications. Increasing the number of radiographic images may increase the reconstruction accuracy, but errors related to the temporal and spatial asynchronization of clinical alternating bi-plane fluoroscopy may also increase. The current study aimed to develop a new approach for subject-specific 3D knee shape reconstruction from multiple asynchronous fluoroscopy images from 2, 4, and 6 X-ray detector views using a CT-based SSM model; and to determine the optimum number of planar images for best accuracy via computer simulations and in vivo experiments. Methods: A CT-based SSM model of the knee was established from 60 training models in a healthy young Chinese male population. A new two-phase optimization approach for 3D subject-specific model reconstruction from multiple asynchronous clinical fluoroscopy images using the SSM was developed, and its performance was evaluated via computer simulation and in vivo experiments using one, two and three image pairs from an alternating bi-plane fluoroscope. Results: The computer simulation showed that subject-specific 3D shape reconstruction using three image pairs had the best accuracy with RMSE of 0.52 ± 0.09 and 0.63 ± 0.085 mm for the femur and tibia, respectively. The corresponding values for the in vivo study were 0.64 ± 0.084 and 0.69 ± 0.069 mm, respectively, which was significantly better than those using one image pair (0.81 ± 0.126 and 0.83 ± 0.108 mm). No significant differences existed between using two and three image pairs. Conclusion: A new two-phase optimization approach was developed for SSM-based 3D subject-specific knee model reconstructions using more than one asynchronous fluoroscopy image pair from widely available alternating bi-plane fluoroscopy systems in clinical settings. A CT-based SSM model of the knee was also developed for a healthy young Chinese male population. The new approach was found to have high mode reconstruction accuracy, and those for both two and three image pairs were much better than for a single image pair. Thus, two image pairs may be used when considering computational costs and radiation dosage. The new approach will be useful for generating patient-specific knee models for clinical applications using multiple asynchronous images from alternating bi-plane fluoroscopy widely available in clinical settings. The current SSM model will serve as a basis for further inclusion of training models with a wider range of sizes and morphological features for broader applications.

Patient-specific instrumentation improves functional kinematics of minimally-invasive total knee replacements as revealed by computerized 3D fluoroscopy.

BACKGROUND AND OBJECTIVES: Minimally-invasive total knee arthroplasty (MIS-TKA) has demonstrated very good short-term success, but its mid- to long-term results remain inconclusive. The success may be related to the tradeoff between a small incision and accurate positioning of the implant components. Patient-specific instrumentation (PSI) aims to improve the accuracy in restoring the knee axis and the clinical outcomes for MIS-TKA, but the results are yet to be confirmed by accurate assessment during functional activities. The purpose of the current study was to measure and compare the in vivo three-dimensional (3D) rigid-body and surface kinematics of MIS-TKA implanted with and without PSI during isolated knee active flexion/extension and sit-to-stand using state-of-the-art 3D model-based fluoroscopy technology. METHODS: Ten patients treated for advanced medial knee osteoarthritis by MIS-TKA without PSI (non-PSI group) and nine with PSI (PSI group) participated in the current study. Each subject performed non-weight-bearing knee flexion/extension and sit-to-stand tasks while the motion of the prosthetic knee was under bi-plane fluoroscopy surveillance. The computer models of each of the knee prosthesis components were registered to the measured fluoroscopy images for each time frame via a novel validated 3D fluoroscopy method. Non-parametric 1-tailed Mann-Whitney tests were performed to detect the differences in the joint and surface kinematic variables every 10° of knee flexion between the non-PSI and PSI groups. The 1-tailed significance level was at α = 0.05. RESULTS: The PSI group showed clear, coupled flexion/internal rotation during activities, while the non-PSI group remained roughly at an externally rotated position with slight internal rotations. The coupled rotation in the PSI group was accompanied by an anterior displacement of the medial contact and a posterior displacement of the lateral contact, which was different from the screw-home mechanism. Neither of the two groups showed the normal roll-back phenomenon, i.e., posterior translation of the femur relative to the tibia during knee flexion. CONCLUSIONS: With the state-of-the-art 3D fluoroscopy method, differences in both the rigid-body and surface kinematics of the prosthetic knees between MIS-TKA with and without PSI were identified. Patients with PSI demonstrated significant positive effects on the reconstructed rigid-body kinematics of the knee, showing clearer coupled flexion/internal rotations - an important kinematic characteristic in healthy knees - than those without PSI during activities with or without weight-bearing. However, none of them showed normal contact patterns. The current findings will be helpful for surgical instrument design, as well as for surgical decision-making in MIS total knee arthroplasty.

Expression of Yes-associated protein 1 gene and protein in oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most common malignancies in the oral and maxillofacial region. Yes-associated protein 1 (YAP1) has been implicated as a bona fide oncogene in solid tumors. We seek to elucidate the role of YAP1 in OSCC tissue. METHODS: We identified YAP1 gene and protein overexpression in 30 OSCC patients and 10 normal oral mucosa tissues by immunohistochemistry, Western blotting and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In the normal oral mucosa by immunohistochemical staining, YAP1 mainly located in both the cytoplasm and nucleus mainly the nuclei of the basal cells. In OSCC, the expression of YAP1 translocated from the nucleus to cytoplasm; YAP1 being mainly located in both the cytoplasm and nucleus of the adjacent mucosa. The expression of YAP1 gradual increased in normal oral mucosa, tumor adjacent mucosa and low grade, middle grade, high grade OSCC tissue by Western blotting. Significant difference was found between the expressions of the normal oral mucosa and OSCC tissue (P < 0.05). The coincidence was detected between the normal oral mucosa and OSCC tissue by RT-PCR (P < 0.05). CONCLUSIONS: YAP1 is involved in the carcinogenesis and development of OSCC. There is a transformation between nucleus and cytoplasm.

[Expression of pJAK, pERK and Cyclin D1 proteins in squamous-cell carcinoma of tongue].

OBJECTIVE: To investigate the expression of JAK, ERK and Cyclin D proteins in squamous-cell carcinoma of tongue. METHODS: The expression of JAK, ERK and Cyclin D1 proteins was determined with SP immunohistochemical method in 30 cases of lingual Squamous cell carcinoma, 20 of normal lingual mucosa, 10 of mild epithelial dysplasia and 20 of severe epithelial dysplasia. RESULTS: The expression of pJAK in lingual squamous-cell carcinoma and epithelial dysplasia was stronger than that of normal lingual mucosa (chi2=37.54, P<0.01), and the expression of pJAK in lingual squamous-cell carcinoma was significantly higher than that of the epithelial dysplasia (chi2=6.83, P<0.05). pJAK expression in squamous-cell carcinoma of low-middle differentiation was stronger than that of high differentiation. There was no significant difference in pERK expression among lingual squamous-cell carcinoma, normal lingual mucosa and epithelial dysplasia. There was a significantly positive correlation between pJAK and Cyclin D1 expression in SCC (r=0.619, P<0.05). There was no significant correlation between the expression of pERK and Cyclin D1 (r=0.231, P>0.05). CONCLUSION: Over-expression of pJAK and Cyclin D1 may be associated with the occurrence and development of squamous-cell carcinoma of the tongue.

[Branchial cleft carcinoma from cleft cyst: report of one case].

Branchial cleft carcinoma is a rare malignancy, there still exist some controversies regarding to the differentiation of branchial cleft carcinomas. This article is aimed to familiarize clinicians with the presentation and treatment of the tumour and explores its origin. A 41-year old man who was seen with a large lesion of branchial cleft carcinoma with a slowly growing mass in the area of the left parotid gland was reported. The histological finding of dysplastic epithelium was next to direct invasive carcinoma. The diagnosis of a branchial cleft carcinoma requires the fulfillment of strict criteria. This case supports the origin of the carcinoma as being from an epithelial-lined cyst.

[Expression of MMP-2 and E-CD in salivary mucoepidermoid carcinoma and its correlation with infiltration, metastasis and prognosis].

OBJECTIVE: To study the expressions of matrix metalloproteinase 2 (MMP2) and E-cadherin (E-CD) in salivary mucoepidermoid carcinoma, and their relationship with clinical stages, pathological grading, lymph node metastasis and prognosis. METHODS: Surgical specimens of salivary mucoepidermiod carcinoma and normal salivary gland tissue were collected. MMP-2 and E-CD were stained immunohistochemically with streptavidin peroxidase method. RESULTS: The expression of MMP-2 was increased and the expression of E-CD was reduced or negative in salivary mucoepidemoid carcinoma compared with those of the normal salivary gland. Expression of MMP-2 and E-CD was closely correlated with lymph node metastasis of the mucoepidermoid carcinoma. MMP-2 was positively correlated with the prognosis of mucoepidermoid carcinoma, and E-CD was negatively correlated to the prognosis of mucoepidermoid carcinoma. CONCLUSION: The expression of MMP-2 and E-CD is closely correlated with the metastasis and prognosis of salivary mucoepidermoid carcinoma.

[Study of the clinicopathology on verruciform xanthoma of the oral cavity].

PURPOSE: Three cases of oral cavity mucosal verruciform xanthoma were studied to investigate the pathogenesis of verruciform xanthoma. METHODS: Immunohistochemical staining with S-P and in situ hybridization using the probe to detect HPV mRNA and MMP-2, MMP-9 RNA. RESULTS: The foam cells were strongly positive for CD68 (KP1) and Vimentin. The cytokeratin, PCNA and S-100 showed negative in foam cells. ISH testing failed to detect HPV (types 6, 11, 16, 18) in any of the three cases of verruciform xanthoma. MMP-2, MMP-9 showed positive staining in epithelial cells and foam cells. CONCLUSIONS: Verruciform xanthoma is most likely not a human papillomavirus associated lesion and the foam cells like that, are most likely derived from monocyte-macrophage lineage.

[Oral lymphoepithelial cyst: report of 3 cases].

Three cases with oral lymphoepithelial cyst were reported in this paper. The most frequent site of the cyst was mouth floor, and the cyst was often misdiagnosed as mucous cyst and other diseases of cyst. Histopathologically, the central cystic lesion was lined with stratified squamous epithelium. Simultaneously, there were lymphoid cells located at the surrounding of the cystic fibrous connective tissue. Oral lymphoepithelial cyst was regarded to originate from secretory duct of the sublingual gland and the small salivary gland epithelium. With chronic stimuli, the epithelium of secretory duct was squamous metaplasia. The deciduous cells in the inner side of the duct induced the infiltration of the surrounding lymphocytes. The relevant literatures were reviewed regarding to the histological origin and the pathogenesis of the disease to provide some references for diagnosis and treatment of this disease.

The effect of hepatic blood inflow occlusion on hepatic cancer treated with diode-laser thermocoagulation.

OBJECTIVE: To assess the effect of temporary occlusion of hepatic blood inflow on hepatic cancer treated with diode-laser induced thermocogation (LITT). METHODS: The carcinoma Walker-256 was implanted in 40 SD rat livers. Twelve days later, the animals were randomly divided into 4 groups. Group A received LITT alone; group B received hepatic artery temporary occlusion during LITT; group C received portal vein temporary occlusion during LITT; group D received hepatic artery and portal vein temporary occlusion during LITT. Tumors were exposed to 810 nm diode-laser light at 0.95 watts for 10 min from a scanner tip applicator placed in the tumor. At the same time, the intrahepatic temperature distribution in rats with liver tumors was measured per 2 min during thermocoagulation. Tumor control was examined immediately 7 and 14 d after thermocoagulation. RESULTS: There was significant difference of intrahepatic temperature distribution in rats with liver tumors among the 4 groups (P<0.05) except when group C samples were compared with group D samples at each time point, and group B samples were compared with group C samples at 120 s (P>0.05). Light microscopic examination of the histologic section samples revealed three separate zones: regular hyperthermic coagulation necrosis zone, transition zone and reference zone. Compared with the samples in group A and group B, group C and group D samples had more clear margin among the three zones. CONCLUSION: The hepatic blood inflow occlusion, especially portal vein hepatic blood inflow occlusion, or all hepatic blood inflow occlusion considerably increased the efficacy of LITT in the treatment of liver cancer.

Experimental study of diode-laser induced thermocoagulation on hepatic tissue with scanner fiber tip.

AIM: To explore a safe, efficient, and cost-effective technique for local thermo-ablation of hepatic tumors. METHODS: The livers of 16 healthy rabbits were thermocoagulated by diode-laser with a hand-made scanner fiber tip, 6 w for 10 min. At the same time, the temperature was measured at 5 and 10 mm from the laser tip. Liver function 7 days post-thermocoagulation was compared to pre-thermocoagulation. Pathological changes were also studied 1 month after laser thermocoagulation. RESULTS: All the rabbits lived and the temperature of hepatic tissues at 0 mm, 5 mm, 10 mm from laser tip reached 96.39+/-3.97 degrees, 60.79+/-6.21 degrees, 46.10+/-4.58 degrees, respectively after 10 min thermocoagulation. There was no significant change in liver function. The hepatic thermocoagulated necrosis and the surrounding fibrosis was 26.0 mm in diameter. Light microscopy observation revealed no surviving cells in the coagulated area. CONCLUSION: Hepatic tissue can be locally ablated safely and effectively by diode-laser with scanner fiber tip, and this technique may be a new method to treat hepatic tumors.

[Experimental study of diode-laser induced thermocoagulation on hepatic tissue with scanner fiber tip].

OBJECTIVE: To seek a safe, efficient, and cost-effective technique for local thermo-ablation of hepatic cancer. METHODS: The livers from 16 healthy rabbits were thermocoagulated by diode-laser with scanner fiber tip, 6 w for 10 mins. At the same time, the temperatures were measured at 0, 5 and 10 mm from laser tip. The pre-thermocoagulative liver function was compared with that of 7 days post-thermocoagulation. The pathologic changes were also observed 1 month after laser thermocoagulation. RESULTS: All the rabbits survived and hepatic tissue temperatures at 0, 5, 10 mm from laser tip reached 96.39 degrees C +/- 3.97 degrees C, 60.79 degrees C +/- 6.21 degrees C, 46.10 degrees C +/- 4.58 degrees C respectively after 10 minutes of thermocoagulation. There were no significant differences in liver function parameters between rabbits of pre-laser thermocoagulation and of post-laser thermocoagulation. Thermocoagulated necrosis of liver tissue with surrounding fibrosis in a diameter of 26.0 mm was formed. Light microscopy revealed coagulative necrosis in the center of the coagulated area without surviving hepatic cells. CONCLUSION: The hepatic tissue can be coagulated safely and effectively by diode-laser with scanner fibertip, and such a technique may provide a new method for the treatment of hepatic carcinoma.

[Experimental study on allogeneic mandible transplantation combined with basic fibroblast growth factor]

OBJECTIVE: To study the effect of basic fibroblast growth factor(b-FGF) on revascularization and bone remodeling of allogeneic mandible transplantation in repair of mandible defects in rabbits. METHODS: The mandible defects of 20 adult rabbits were created in both sides. The defects on the left side were implanted with allogeneic bone and local administration of b-FGF; the defects on the right side were only repaired with allogeneic bone as control group. At 1, 3 months after operation, the revascularization and bone remodeling were observed by ink-gelation vascular perfusion-transparency and histological examination. RESULTS: The allogeneic bone and b-FGF group had more marked vascularization and more quick and complete bone formation than control group. CONCLUSION: b-FGF can improve revascularization and bone formation after allogeneic mandible transplantation; allogeneic bone combined with b-FGF is a promising bone substitute in clinical uses.