Morphological characteristics of the Lisfranc ligament.

BACKGROUND: This study aimed to clarify the morphological characteristics of the Lisfranc ligament and the cuneiform 1-metatarsal 2&3 plantar ligament (CMPL). METHODS: Forty legs from 20 cadavers were examined. Classification proceeded according to the number of fiber bundles in the Lisfranc ligament and the CMPL. Morphological features measured were fiber bundle length, width, thickness, and angle. RESULTS: In Type I-a, the Lisfranc ligament and the CMPL were a single fiber bundle; in Type I-b, the Lisfranc ligament was a single fiber bundle, and the CMPL was two fiber bundles; in Type II-a, the Lisfranc ligament was a two fiber bundle, and the CMPL was a single fiber bundle; in Type II-b, the Lisfranc ligament and the CMPL were two fiber bundles; in Type III-a, the Lisfranc ligament was three fiber bundles, and the CMPL was a single fiber bundle; in Type III-b, the Lisfranc ligament was three fiber bundles, and the CMPL was two fiber bundles; in Type IV, the Lisfranc ligament and the CMPL could not be separated. Type I-a was seen in 37.5%, Type I-b in 10%, Type II-a in 30%, Type II-b in 7.5%, Type III-a in 7.5%, Type III-b in 2.5%, and Type IV in 5%. The Lisfranc ligament was significantly larger than the CMPL in total fiber bundle width, total fiber bundle thickness, and total fiber bundle angle. CONCLUSION: The Lisfranc ligament had up to 3 fiber bundles and the CMPL had one or two fiber bundles; classifications were four types and two subgroups.

Morphological features of the deep component of the posterior inferior tibiofibular ligament.

PURPOSE: The deep component of the posterior inferior tibiofibular ligament (PITFL) was classified by type in this large-scale cadaveric study to provide basic information that will help elucidate the mechanisms underlying ankle joint posterior impingement syndrome. METHODS: This investigation examined 100 legs from 49 Japanese cadavers (mean age at death, 79 ± 11 years; 58 sides from men, 42 from women). In classification, absence of an independent fiber of the deep component of the PITFL were classified as Type I, an independent fiber of the deep component of the PITFL was classified as Type II-a, an independent fiber of the deep component of the PITFL with bundles of fibers connected to the posterior intermalleolar ligament (PIML) was classified as Type II-b, and an independent fiber of the deep component of PITFL with a band shape connected to the PIML was classified as Type III. RESULTS: A deep component of the PITFL was present in all specimens. An independent fiber of the deep component of the PITFL was present in 37 legs (37%), connecting to the deep component of the PITFL and PIML in 26 (70.3%). Several types of deep component of the PITFL were identified: Type I in 63 legs (63%); Type II-a in 11 (11%); Type IIb in 12 (12%); and Type III in 14 (14%). No significant differences were seen between the right and left legs. Type I male were significantly more than Type I female (p < 0.05). Type III female were significantly more than Type III male (p < 0.05). CONCLUSIONS: Strong relationships exist between the PITFL and PIML.

Morphological features of the cervical ligament.

PURPOSE: The purpose of this study was to clarify the morphological characteristics of the cervical ligament (CL). METHODS: This study examined 80 legs from 40 Japanese cadavers. The CL was classified by the number of fiber bundles. The morphological features measured were fiber bundle length, width, thickness, and angle with the sagittal plane. RESULTS: The CL was classified as follows: Type I, the CL is a single fiber; Type II, the CL consists of a superficial fiber and an inferior fiber; and Type III, the CL consists of a superficial fiber, intermediate fiber, and inferior fiber. Type I was seen in 15 feet, Type II in 57 feet, and Type III in 8 feet. In comparisons of morphological features within each type, significant differences were seen in fiber bundle length, width, and angle between superior fiber bundles and inferior fiber bundles of Type II and Type III. In comparison among types, the total fiber bundle width was significantly wider in Type II and Type III than in Type I, and the angle was significantly smaller in Type III than in Type I. CONCLUSION: The results of this study suggested that each type may have different sub-talar joint control functions.

Morphological features of the inferior fascicle of the anterior inferior tibiofibular ligament.

In this study, the inferior fascicle of the anterior inferior tibiofibular ligament (AITFL) was classified to provide basic information to help elucidate the mechanism of ankle joint anterolateral impingement, and the morphological features of each type were compared for the purpose of clarification. This investigation examined 100 feet from 52 cadavers. The AITFL was classified into four types according to the presence or absence of the inferior fascicle and the positional relationship between the AITFL and the inferior fascicle of the AITFL. The morphological features of the AITFL that were measured included the fibre bundle length, fibre bundle width, fibre bundle angle, and the distance between the joint levels. A distinct, independent inferior fascicle of the AITFL was identified in 15 feet (15%). There were no significant differences in the morphological features based on differences in the AITFL classification. Therefore, these findings suggest that the presence or absence of the inferior fascicle and the difference in the positional relationship between the AITFL and the inferior fascicle of the AITFL are less likely to be involved in impingement during ankle dorsiflexion.

Morphological features of the posterior intermalleolar ligament.

PURPOSE: In the present study, the posterior intermalleolar ligament (PIML) was classified by type using large-scale cadavers to provide basic information to help elucidate the mechanism of ankle joint posterior impingement syndrome. METHODS: This investigation examined 100 legs from 49 Japanese cadavers (mean age at death, 79 ± 11 years; 58 sides from men, 42 from women). In the classification method, an absent PIML was classified as Type I, a PIML with one fiber bundle (attachment to one place) was Type II, a PIML with two fiber bundles (attachment to two places) was Type III, and a PIML with three fiber bundles (attachment to three or more places) was Type IV. Furthermore, according to other adhering tissues, they were further subdivided and classified by type. RESULTS: There were various types of PIML: 19 (19%) Type I; 24 (24%) Type II; 23 (23%) Type III; and 34 (34%) Type IV. A PIML was present in 81 legs (81%). There were no significant differences between men and women and between left and right sides. CONCLUSIONS: The complex relationships of the PIML with the surrounding ligaments and tissues are considered to be among the factors that make interpretation of imaging findings difficult.

Morphological features of the bifurcated ligament.

INTRODUCTION: Damage to the bifurcate ligament is one of the most difficult injuries to diagnose from imaging techniques. A probable reason for this is that the morphological characteristics of this structure have yet to be sufficiently elucidated. We, therefore, endeavored to elucidate the morphological characteristics of the bifurcate ligament through a large-scale study involving numerous specimens. MATERIALS AND METHODS: This study included 100 feet from 52 formalin-fixed cadavers. The bifurcate ligament was classified into three types: presence of both calcaneonavicular ligament and calcaneocuboid ligament (Type I); absence of calcaneocuboid ligament (Type II); and absence of calcaneonavicular ligament (Type III). Morphological characteristics of the bifurcate ligament were determined by measuring fiber bundle length, width, and thickness at the center of each ligament. RESULTS: This classification resulted in 68 Type I feet (68%), 32 Type II feet (32%), and 0 Type III feet (0%). The calcaneonavicular ligament was 20.8 ± 2.9 mm long, 4.9 ± 1.2 mm wide, and 3.8 ± 1.1 mm thick. The calcaneocuboid ligament was approximately 10.5 ± 2.7 mm long, 4.7 ± 2.4 mm wide, and 1.5 ± 0.6 mm thick. The bifurcate ligament was located deep under the extensor hallucis brevis and extensor digitorum brevis muscles in all specimens. The calcaneal origin of the calcaneonavicular ligament was situated deep under the interosseous talocalcaneal ligament in all specimens. Two sides were identified in which the calcaneocuboid ligament was located deep under the dorsal calcaneocuboid ligament. CONCLUSION: Such variations and positional relationships were suggested to be factors complicating the diagnostic imaging of bifurcate ligament injuries. The present study results will likely form useful basic data for diagnostic imaging.

Cervical curvature variations in patients with infraocclusion.

The purpose of this study was to observe the variations of cervical curvature in patients with infraocclusion, and to compare this with the controls. In this study, the infraocclusion criteria were defined with the Pr-id as <17 mm on the cephalometric image. The subjects were 32 patients with infraocclusion, and 28 controls which matched the distribution for gender and age. The six points of inquiry were as follows: (i) cervical vertebra height, (ii) neck alignment, (iii) ratio of lower facial height, (iv) vertical dimension of occlusion, (v) cervical angle and (vi) occlusal angle. In over 90% of the patients with infraocclusion, the cervical curvature was classified as straight or kyphosis. Conversely, in 36% of the control subjects, the cervical curvature was classified as lordosis. There was a weak positive correlation between the vertical dimension of occlusion and the cervical curvature in all subjects. In the control group, there was a significant and strong positive correlation between the age and cervical curvature, and a strong negative correlation between age and cervical angle and occlusal angle. Conversely, in the patients with infraocclusion, age was only correlated with the ratio of lower facial height. The prevalence of non-lordosis in the patients with infraocclusion was higher in comparison with the control group in our study, and the previous large-scale study of Japanese. However, there was merely a weak positive correlation between the cervical curvature and the vertical dimension of occlusion.

Lewis acid-catalyzed ring-opening reactions of semicyclic N,O-acetals possessing an exocyclic nitrogen atom: mechanistic aspect and application to piperidine alkaloid synthesis.

Ring-opening reactions of semicyclic N,O-acetals possessing an exocyclic nitrogen atom with silicon-based nucleophiles (silyl enol ethers, ketene silyl acetals, allylic silanes, and trimethylsilyl cyanide) were systematically studied for the first time. It was found that the reactions were effectively catalyzed by a Lewis acid, trimethylsilyl trifluoromethanesulfonate (TMSOTf), to afford 1,4- and 1,5-amino alcohols in high yields. In reactions of 3-oxygen functionalized semicyclic N,O-acetals, high 1,2-syn-diastereoselectivity was obtained. By 1H NMR experiment, the formation of the O-trimethylsilylated ring-opened product was observed as the initial product. Furthermore, the epimerization between the diastereomers of a 3-benzyloxy semicyclic N,O-acetal suggested the transient formation of an acyclic iminium ion species as a reactive intermediate. It was also found that 3-acetoxy and 3-benzyloxy N,O-acetals showed a tendency for the larger nucleophile to provide higher syn-selectivity, while 3-tert-butyldiphenylsilyloxy N,O-acetals showed the opposite tendency. These stereochemical outcomes can be rationalized by assuming four transition state models for the acyclic iminium ion intermediate. The synthetic utility of the reaction has been demonstrated in the diastereoselective synthesis of piperidine alkaloids, (+)-isofebrifugine and (+/-)-sedacryptine.

Highly stereoselective synthesis of homoallylic amines based on addition of allyltrichlorosilanes to benzoylhydrazones.

Allyltrichlorosilanes reacted with benzoylhydrazones in DMF without the use of any catalyst to afford the corresponding homoallylic benzoylhydrazines in good to high yields. The reactions proceeded at 0 degrees C to room temperature under mild conditions. In addition, it was found that the reactions tolerated well the steric hindrance of hydrazones and allyltrichlorosilanes. Indeed, ketone-derived benzoylhydrazones reacted with allyltrichlorosilane smoothly to afford the corresponding N'-tert-alkyl-N-benzoylhydrazines in high yields. In crotylation with (E)- and (Z)-crotyltrichlorosilanes, syn- and anti-adducts were stereospecifically obtained, respectively. These reactions are most likely to proceed via a cyclic chairlike transition state where the R group takes an axial position. When alpha-heteroatom-substituted chiral benzoylhydrazones were used, high anti-diastereoselectivities were observed. These adducts can be readily converted to homoallylic amines in high yields without epimerization.

Necrotizing vasculitis and Sarcocystis: a cause-and-effect relationship?

We have described a patient with an unusual infection with Sarcocystis and a necrotizing vasculitis with subcutaneous nodules, and have discussed the possibility of a cause-and-effect relationship between these two entities and the available diagnostic methods and therapeutic measures.