Anatomic evaluation of the triceps tendon insertion at the proximal olecranon regarding placement of fracture fixation devices.

PURPOSE: Olecranon fractures, especially with a small proximal fragment, remain a surgical challenge. Soft tissue irritation and affection of the triceps muscle bear a risk of complications. In order to find an area for a soft-tissue sparing placement of implants in the treatment of olecranon fractures, we aimed to define and measure the segments of the proximal olecranon and evaluate them regarding possible plate placement. METHODS: We investigated 82 elbow joints. Ethical approval was obtained from the local ethics committee, After positioning in an arm holder and a posterior approach we described the morphology of the triceps footprint, evaluated and measured the surface area of the triceps and posterior capsule and correlated the results to easily measurable anatomical landmarks. RESULTS: We found a bipartite insertional footprint with a superficial tendinous triceps insertion of 218.2 mm2 (± 41.2, range 124.7-343.2), a capsular insertion of 159.3 mm2 (± 30.2, range 99.0-232.1) and a deep, muscular triceps insertion area of 138.1 mm2 (± 30.2, range 79.9-227.5). Olecranon height was 26.7 mm (± 2.3, range 20.5-32.2), and olecranon width was 25.3 mm (± 2.4, range 20.9-30.4). Average correlation between the size of the deep insertion and ulnar (r = 0.314) and radial length (r = 0.298) was obtained. CONCLUSIONS: We demonstrated the bipartite morphology of the distal triceps footprint and that the deep muscular triceps insertion area by its measured size could be a possible site for the placement of fracture fixations devices. The size correlates with ulnar and radial length.

Suturing methods in prolapse surgery: a biomechanical analysis.

INTRODUCTION: Pelvic organ prolapse is a common problem in urogynecological surgery. Abdominal and laparoscopic sacrocolpopexy is currently considered to be the gold standard of treatment. The main problem remains the anatomical point of fixation as well as how sutures are placed. We evaluated the biomechanical difference between an in-line ligament suture versus an orthogonal ligament suture and a single suture versus a continuous suture at the anterior longitudinal ligament in an in-vitro, sacrocolpopexy model. METHODS: Biomechanical in-vitro testing was performed on human, non-embalmed, female cadaver pelvises. An Instron test frame (tensinometer) was used for load/ displacement analysis. The average patient age was 75 years. Ligament preparation yielded 15 ligaments available for testing. Recorded parameters were the ultimate load, failure displacement, and stiffness. RESULTS: This in-vitro analysis of different suturing methods showed the difference between an orthogonal and an in-line approach to be the ultimate load. Orthogonal sutures displayed an ultimate load of 80 N while in-line suturing yielded only 57 N (p < 0.05). For the anterior longitudinal ligament, this study demonstrated that continuous suture is significantly superior to a single suture regarding failure displacement (p < 0.05). CONCLUSION: We established baseline biomechanical parameters for the sacrospinous ligament and anterior longitudinal ligament. An orthogonal suture is superior to an in-line suture in an in-vitro model. A continuous suture is superior to a single suture at the anterior longitudinal ligament. Clinical trials might be able to evaluate whether any clinical significance can be established from these findings.

Laparoscopic pectopexy: a follow-up cyclic biomechanical analysis determining time to functional stability.

INTRODUCTION: Pectopexy, a laparoscopic method for prolapse surgery, showed promising results in previous transient testing by this group. It was shown that a single suture, yielding an ultimate load of 35 N, was equivalent to continuous suturing. This was demonstrated in an in vitro cadaver study. This transient data were used to establish an elastic stress-strain envelope. It was now possible to proceed to dynamic in vitro analysis of this surgical method to establish time to functional stability. METHODS: Cyclic testing of this fixation method was performed on human female embalmed cadaver (cohort 1) and fresh, non-embalmed cadaver (cohort 2) pelvises. The testing envelope was 5-25 N at a speed of 1 mm/s. 100 load regulated cycles were applied. RESULTS: 100 cycles were completed with each model; no overall system failure occurred. Steady state, i.e., functional stability was reached after 14.5 (± 2.9) cycles for the embalmed group and after 19.1 (± 7.2) cycles for the non-embalmed group. This difference was statistically significant p = 0.00025. CONCLUSION: This trial showed in an in vitro cyclic testing of the pectopexy method that functional stability may be achieved after no more than 19.1 cycles of load exposure. When remaining within the established load envelope of below 25 N, patients do not need to fear global fixation failure. Testing did demonstrate differences in non-embalmed and embalmed cadaver testing. Embalmed cadaver testing tends to underestimate time to steady state by 26.3%.

Peroneal nerve location at the fibular head: an anatomic study using 3D imaging.

INTRODUCTION: Injuries to the peroneal nerve are a common complication in operative treatment of proximal tibial or fibular fractures. To minimize the risk of iatrogenic injury to the nerve, detailed knowledge of the anatomy of the peroneal nerve is essential. Aim of this study was to present a detailed description of the position and branching of the peroneal nerve based on 3D-images to assist preparation for surgical approaches to the fibular head and the tibial plateau. METHODS: The common peroneal nerve, the deep and the superficial peroneal nerve were marked with a radiopaque thread in 18 formalin-embalmed specimens. Three-dimensional X-ray scans were then acquired from the knee and the proximal lower leg in full extension of the knee. In 3D-reconstructions of these scans, distances of the common peroneal nerve and its branches to clearly defined osseous landmarks were measured digitally. Furthermore, the height of the branching of the common peroneal nerve was measured in relation to the landmarks. RESULTS: The mean distance of the common peroneal nerve at the level of the tibial plateau to its posterior osseous limitation was 7.92 ± 2.42 mm, and 1.31 ± 2.63 mm to the lateral osseous limitation of the tibia. In a transversal plane, distance of the common peroneal nerve branching was 27.56 ± 3.98 mm relative to the level of the most proximal osseous extension of fibula and 11.77 ± 6.1 mm relative to the proximal extension of the tibial tuberosity. The deep peroneal nerve crossed the midline of the fibular shaft at a distance of 22.14 mm ± 4.35 distally to the most proximal extension of the fibula, the superficial peroneal nerve at a distance of 33.56 mm ± 6.68. CONCLUSION: As the course of the peroneal nerve is highly variable in between individuals, surgical dissection for operative treatment of proximal posterolateral tibial or fibular fractures has to be done carefully. We defined an area were the peroneal nerve and its branches are unlikely to be found. However, specific safe zones should not be utilized due to the individual anatomic variation.

Investigation of umbilical venous vessels anatomy and diameters as a guideline for catheter placement in newborns.

Umbilical cord catheters (UCC) are important for the primary care of critically ill newborns. To analyze anatomical variations of the umbilical vein (UV) and its further course, we performed abdominal spiral-CT examinations on stillborns. The aim of the study was to explore the high incidence of mal-positioned UCCs and to improve their positioning. Eighteen stillborns were investigated (29.2 weeks ± 6.7 weeks (IQR)). CTs were performed using either air or contrast medium injection into the UV. We measured the diameter at the narrowest points of (i) the umbilical vein, (ii) the segmental portal vein, (iii) the left portal vein, (iv) the umbilical recess, and (v) the ductus venosus. The branching angles between (a) the umbilical vein and intrahepatic veins and (b) the ductus venosus and umbilical recess were measured. The diameter of the UV increases from 3.4 to 11 mm (median [IQR]:4.6 mm [4.2-6.9]: r2 = 0.64). The left portal vein has a larger diameter (3.6 mm [2.6-4.55]; r2 = 0.43) than the left segmental portal vein (2.3 mm [1.8-2.75]; r2 = 0.23). The diameter of the ductus venosus (2.5 mm [1.6-3.4]; r2 = 0.59) is half that of the umbilical recess (5.1 mm [3.3-6.2]; r2 = 0.43). The most obtuse angle is formed by the junction between the umbilical recess and ductus venosus (151° [133-159]; r2 = 0.001). The branch angle from the outgoing UV into the left portal vein is more obtuse (128° [123-144]; r2 = 0.0001) than that of the segmental portal vein (115° [105-119]; r2 = 0.0001). To avoid mal-positioning, our data suggest the use of a soft catheter. The UV and its extensions are wide enough to admit a 4 Fr. catheter without complete obstruction. Clin. Anat. 31:269-274, 2018. © 2017 Wiley Periodicals, Inc.

[The bare area of the proximal ulna : An anatomical study on optimizing olecranon osteotomy]. / Die Bare Area der proximalen Ulna : Eine anatomische Studie zur Optimierung der Olekranonosteotomie.

BACKGROUND: Olecranon osteotomy is an established approach for the treatment of distal humerus fractures. It should be performed through the bare area of the proximal ulna to avoid iatrogenic cartilage lesions. OBJECTIVES: The goal of this study was to analyze the anatomy of the proximal ulna with regard to the bare area and, thereby, to optimize the hitting area of the bare area when performing olecranon osteotomy. MATERIALS AND METHODS: The bare areas of 30 embalmed forearm specimens were marked with a radiopaque wire and visualized three-dimensionally with a mobile C­arm. By means of 3D reconstructions of the data sets, the following measurements were obtained: height of the bare area; span of the bare area-hitting area in transverse osteotomy; ideal angle for olecranon osteotomy to maximize the hitting area of the bare area; distance of the posterior olecranon tip to the entry point of the transverse osteotomy and the ideal osteotomy. RESULTS: The height of the bare area was 4.92 ± 0.81 mm. The hitting area of the transverse osteotomy averaged 3.73 ± 0.89 mm. The "ideal" angle for olecranon osteotomy was 30.7° ± 4.19°. The distance of the posterior olecranon tip to the entry point was 14.08 ± 2.75 mm for the transverse osteotomy and 24.21 ± 3.15 mm for the ideal osteotomy. The hitting area of the bare area in the ideal osteotomy was enhanced significantly when compared to the transverse osteotomy (p < 0.0001). CONCLUSIONS: This study provides guide values for correct osteotomy of the olecranon. Moreover, a 30° angulation of the osteotomy can significantly increase the hitting area of the bare area.

Laparoscopic Pectopexy: A Biomechanical Analysis.

INTRODUCTION: Pectopexy, a laparoscopic method for prolapse surgery, showed promising results in recent literature. Further improving this approach by reducing surgical time may decrease complication rates and patient morbidity. Since laparoscopic suturing is a time consuming task, we propose a single suture /mesh ileo-pectineal ligament fixation as opposed to the commonly used continues approach. METHODS: Evaluation was performed on human non-embalmed, fresh cadaver pelves. A total of 33 trials was performed. Eight female pelves with an average age of 75, were used. This resulted in 16 available ligaments. Recorded parameters were ultimate load, displacement at failure and stiffness. RESULTS: The ultimate load for the mesh + simplified single "interrupted" suture (MIS) group was 35 (± 12) N and 48 (± 7) N for the mesh + continuous suture (MCS) group. There was no significant difference in the ultimate load between both groups (p> 0.05). This was also true for displacement at failure measured at 37 (± 12) mm and 36 (±5) mm respectively. There was also no significant difference in stiffness and failure modes. CONCLUSION: Given the data above we must conclude that a continuous suture is not necessary in laparoscopic mesh / ileo-pectineal ligament fixation during pectopexy. Ultimate load and displacement at failure results clearly indicate that a single suture is not inferior to a continuous approach. The use of two single sutures may improve ligamental fixation. However, overall stability should not benefit since the surgical mesh remains the limiting factor.

Expression pattern of BMPs during chick limb development.

In vertebrates, BMPs (bone morphogenic proteins) play critical roles in establishing the basic embryonic body plan and are involved in the development of a large variety of organs and tissues. Here, we analyzed the expression pattern of various BMPs (2, 4, 5 and 7) by whole mount in situ hybridization during chick limb development. In limb, expression of BMPs suggests evolutionary conserved mechanisms of BMP-dependent differentiation between lower and higher vertebrates. During the early developmental stages, BMP-2 and BMP-7 are expressed in the posterior distal mesenchyme leaving a less prominent expression anteriorly. BMP-4 is initially expressed in the anterior mesenchyme and spreads later to the whole mesenchyme leaving a stronger expression at the anterior side. From HH-stage 25, expression of BMP-4 is observed in the anterior-posterior margins of the limb bud. The BMPs 2, 4 and 7 are expressed strongly in the AER, whereas BMP-5 is expressed as a weak signal in the distal mesoderm during the early stages of limb development. Later from HH-stage 25 onwards, BMP-5 is expressed in the dorsal and ventral muscular mass of the developing limb. As digits become identifiable, expression of BMPs are observed in the interdigital mesenchyme and can also be detected along the contours of the developing phalanges and at the distal tips of the digits. All these BMPs are found to be expressed in the developing feather buds from day 8 onwards.

cDermo-1 expression indicates a role in avian skin development.

Basic helix-loop-helix (bHLH) transcription factors have been shown to be important regulatory proteins for tissue determination and differentiation. We cloned the chicken homologue of the gene of the murine Twist-related bHLH protein Dermo-1, which we named cDermo-1, and analyzed its sequence and embryonic expression. Our sequence data suggest a decisive role of Dermo-1 proteins in the evolution of amniote skin. We present a detailed analysis of cDermo-1 expression during avian embryonic development. cDermo-1 is first expressed in a variety of mesodermal tissues of the chick embryo including the limb buds, but later becomes restricted to the subectodermal mesenchyme of the integument and the developing feather buds, indicating a role of cDermo-1 during avian skin and feather development.

SF/HGF is a mediator between limb patterning and muscle development.

Scatter factor/hepatocyte growth factor (SF/HGF) is known to be involved in the detachment of myogenic precursor cells from the lateral dermomyotomes and their subsequent migration into the newly formed limb buds. As yet, however, nothing has been known about the role of the persistent expression of SF/HGF in the limb bud mesenchyme during later stages of limb bud development. To test for a potential role of SF/HGF in early limb muscle patterning, we examined the regulation of SF/HGF expression in the limb bud as well as the influence of SF/HGF on direction control of myogenic precursor cells in limb bud mesenchyme. We demonstrate that SF/HGF expression is controlled by signals involved in limb bud patterning. In the absence of an apical ectodermal ridge (AER), no expression of SF/HGF in the limb bud is observed. However, FGF-2 application can rescue SF/HGF expression. Excision of the zone of polarizing activity (ZPA) results in ectopic and enhanced SF/HGF expression in the posterior limb bud mesenchyme. We could identify BMP-2 as a potential inhibitor of SF/HGF expression in the posterior limb bud mesenchyme. We further demonstrate that ZPA excision results in a shift of Pax-3-positive cells towards the posterior limb bud mesenchyme, indicating a role of the ZPA in positioning of the premuscle masses. Moreover, we present evidence that, in the limb bud mesenchyme, SF/HGF increases the motility of myogenic precursor cells and has a role in maintaining their undifferentiated state during migration. We present a model for a crucial role of SF/HGF during migration and early patterning of muscle precursor cells in the vertebrate limb.

Mercury concentrations in fetuses with malformations.

The total mercury concentrations in placenta, kidney and liver of 59 fetuses with malformations were detected and measured by cold-vapour atomic absorption spectrometry. Median values were 13 micrograms/kg for placenta, 20 micrograms/kg for kidney and 31 micrograms/kg for liver, based on the use of paraffin-embedded tissue (pt), which generally leads to values of concentration double those obtained on a wet weight basis. The tissue concentrations presented here are in the same range as results from other studies. Measurements in a control group of 56 fetuses without malformations from the same geographical region were also carried out. These demonstrated a median value of the liver-Hg-burden of 27 micrograms/kg (pt). The higher liver concentrations of the fetuses with malformations could be explained by growth retardation, leading to seemingly higher tissue concentrations of mercury. Regarding the results according to the organs affected by malformations, no abnormally high Hg-concentrations in the liver of any group were detected. Summing up, our investigations show no evidence of mercury implication in these malformations, and it was finally concluded that the mercury burden of the population in this region would not lead to organ malformations in the developing fetus.