Uncemented hip revision cup as an alternative for T-type acetabular fractures: A cadaveric study

BACKGROUND

The current rise in elderly patients with compromised bone quality complicates the surgical treatment of acetabular T-type fractures (AO type 62B2 fractures). There is on ongoing discussion about the treatment options, mostly consisting of an open reduction and internal fixation (ORIF) with or without primary or secondary total hip arthroplasty (THA). Yet, these patients are oftentimes unable to fulfil weight-bearing restrictions and mostly present with an unavailability of a stable anchor site. Consequently, this study investigates the feasibility of a cementless hip revision cup for acetabular T-type fractures and compares its biomechanical properties to ORIF.

HYPOTHESIS

The cementless hip revision cup provides sufficient biomechanical stability under the simulation of full weight-bearing.

PATIENTS AND METHODS

The study compared two groups of human cadaveric hip bones with T-type fractures, of whom 6 subjects were treated with ORIF (6 male; mean age: 62±17years; mean body weight: 75±15) versus 6 subjects treated with a cementless hip revision cup (2 male; 69±12 years; 73±15kg). The group-assignment was controlled for comparable BMD results (mean BMD: ORIF 110±37 mg Ca-Ha/mL versus hip revision cup 134±32 mg Ca-Ha/mL). To compare for biomechanical stability cyclic loading was applied measuring the force and dislocation of the fracture gap at standardized bone loci using an all-electric testing machine and a 3D-ultrasound measuring system.

RESULTS

Comparing superior pubic ramus versus iliac wing (cementless hip revision cup versus ORIF [mean±standard deviation]: 5.8±2.0 versus 7.0±3.2; p=0.032) as well as sacral ala versus iliac wing (4.6±2.2 versus 6.4±3.7; p=0.002), the cementless revision cup achieved a significantly higher stability than the plate osteosynthesis.

CONCLUSION

Revision cup and ORIF withstood biomechanical loading forces exceeding full weight-bearing in this biomechanical study. The results of our study suggest that the cementless hip revision cup might be promising alternative to the current standard care of ORIF with or without primary THA.

LEVEL OF EVIDENCE

III; case control experimental study.

Improving stability of atlantoaxial fusion: a biomechanical study

PURPOSE

The incidence of atlanto-axial injuries is continuously increasing and often requires surgical treatment. Recently, Harati developed a new procedure combining polyaxial transarticular screws with polyaxial atlas massae lateralis screws via a rod system with promising clinical results, yet biomechanical data is lacking. This biomechanical study consequently aims to evaluate the properties of the Harati technique.

METHODS

Two groups, each consisting of 7 cervical vertebral segments (C1/2), were formed and provided with a dens axis type 2 fracture according to Alonzo. One group was treated with the Harms and the other with the Harati technique. The specimen was loaded via a lever arm to simulate extension, flexion, lateral flexion and rotation. For statistical analysis, dislocation (°) was measured and compared.

RESULTS

For extension and flexion, the Harati technique displayed a mean dislocation of 4.12° ± 2.36° and the Harms technique of 8.48° ± 1.49° (p < 0.01). For lateral flexion, the dislocation was 0.57° ± 0.30° for the Harati and 1.19° ± 0.25° for the Harms group (p < 0.01). The mean dislocation for rotation was 1.09° ± 0.48° for the Harati and 2.10° ± 0.31° for the Harms group (p < 0.01). No implant failure occurred.

CONCLUSION

This study found a significant increase in biomechanical stability of the Harati technique when compared to the technique by Harms et al. Consequently, this novel technique can be regarded as a promising alternative for the treatment of atlanto-axial instabilities.

Effect of angular correction during posterior instrumentation of spinal fractures on postoperative outcomes and quality of life

BACKGROUND

Posterior instrumentation using pedicle screws and rods is the most commonly used technique for the treatment of thoracolumbar fractures of the spine. The procedure aims to restore the neurologic and biomechanical functions of the spine and allows for early mobilization and rapid reintegration into society. It is unclear whether the magnitude of correction has an effect on postoperative outcomes.

OBJECTIVE

We aimed to determine whether the magnitude of sagittal angular correction during posterior instrumentation of the spine had an effect on postoperative quality of life, pain and function outcomes as measured using the EQ5D-3L and the Core Outcome Measures Index (COMI) instruments. We also aimed to quantify the correlation between EQ5D-3L and COMI scores.

METHODS

We analyzed the pre- and postoperative radiographs of 52 patients who underwent percutaneous pedicle screw placement for thoracolumbar fractures, as well as their self-reported EQ5D-3L and COMI quality of life, pain and functional outcome scores. Regression models were constructed to estimate the effect that the magnitude of Cobb angle correction had on postoperative outcomes. We also estimated the correlation between EQ5D-3L and COMI scores.

RESULTS

The median EQ5D-3L TTO score was 0.9 (range, -0.1 to 1). The median COMI score was 3.1 (range, 0 to 10). There was no significant effect of the magnitude of correction on EQ5d-3L TTO scores (p= 0.3379; R= 0.36) or on COMI scores (p= 0.3379; R= 0.15). Age and bone mineral density were not found to be significant predictors of outcome (p= 0.05). There was a strong correlation between the EQ5D-3L TTO and COMI scores (r=-0.62).

CONCLUSION

The magnitude of Cobb angle correction during pedicle screw instrumentation of thoracolumbar fractures did not influence quality of life, pain or function outcomes. There was good correlation between EQ5D-3L TTO scores and COMI scores.

Does augmentation increase the pull-out force of symphyseal screws? A biomechanical cadaver study

Purpose

Open reduction and internal fixation using anterior plate osteosynthesis currently represents the gold standard for the treatment of symphyseal disruptions. Since postoperative screw loosening with consequent implant failure is frequently observed, this study aims to evaluate if and to what extent augmentation can increase the pull-out force of symphyseal screws to improve the constructs stability.

Methods

Twelve human cadaveric anterior pelvic rings were separated at the symphyseal joint for bilateral testing, consequently achieving comparable sites. First, one non-augmented screw was drilled into the superior pubic ramus, whereas the contralateral side was primarily augmented. The screws were then withdrawn with a constant speed of 10 mm/min and the fixation strengths determined by the force (N) displacement (mm) curve. Finally, the primary non-augmented site was secondary augmented, representing revision surgery after initial implant failure, and the corresponding fixation strength was measured again.

Results

Augmentation compared to non-augmented screws displayed significantly higher pull-out forces with an increase in pull-out force by 377% for primary and 353% for secondary augmentation (p < 0.01). There was no significant difference in the pull-out force comparing primary and secondary augmentation (p = 0.74).

Conclusions

Primary and secondary augmentation significantly increases the stability of symphyseal screws and, therefore, potentially decreases rates of implant failure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-022-01963-6.

A Novel Device for Closed Reduction and Percutaneous Fixation of Thoracolumbar Fractures

BACKGROUND/AIM

Open surgical reduction/fixation of thoracolumbar fractures results in significant soft-tissue trauma and related complications. Minimally-invasive technical developments could deliver similar radiological outcomes, while avoiding the related complications. We evaluated radiological and perioperative outcomes in thoracolumbar fractures by using a novel minimally-invasive device.

PATIENTS AND METHODS

Twenty-six patients with 29 thoracolumbar fractures using the NForce device were analyzed. Postoperative reduction and alignment were assessed by radiographic measurement of the local kyphosis angle (LKA) up until a follow-up period of 9 months.

RESULTS

Postoperative imaging revealed an average reduction of traumatic kyphosis of 8.25° (±7.72°) with an average postoperative LKA of 3.24° (±8.97°). The highest degree of reduction was 27.39°. The mean LKA had increased to 5.08° (±5.17°) at 3 months postoperative, 5.43° (±4.32°) at 6 months and 6.21° (±3.82°) at 9 months.

CONCLUSION

The minimally invasive NForce system is effective in performing anatomic percutaneous reduction/fixation.

Novel minimally invasive tape suture osteosynthesis for instabilities of the pubic symphysis: a biomechanical study

INTRODUCTION

Open book fractures are challenging injuries oftentimes requiring surgical treatment. The current treatment of choice is symphyseal plating, which requires extensive surgery and entirely limits physiological movement of the symphyseal joint, frequently resulting in implant failure. Therefore, we investigated the biomechanical properties of a semi-rigid implant (modified SpeedBridge^™) as a minimally invasive tape suture construct for the treatment of open book fractures and evaluated the superiority of two techniques of implementation: criss-cross vs. triangle technique.

MATERIALS AND METHODS

Nine synthetic symphyseal joints were dissected creating an open book fracture. The different osteosynthesis methods (plating, modified SpeedBridge^™ in criss-cross/triangle technique) were then applied. All constructs underwent horizontal and vertical loading, simulating biomechanical forces while sitting, standing and walking. For statistical analysis, dislocation (mm) and stiffness (N/mm) were calculated.

RESULTS

Symphyseal plating for the treatment of open book fractures proved to be a rigid osteosynthesis significantly limiting the physiological mobility of the symphyseal joint (dislocation: 0.08 ± 0.01 mm) compared to the tape sutures (dislocation: triangle technique 0.27 ± 0.07 mm, criss-cross technique 0.23 ± 0.05 mm) regarding horizontal tension (p < 0.01). Both modified SpeedBridge^™ techniques showed sufficient biomechanical stability without one being superior to the other (p > 0.05 in all directions). Considering vertical loading, no statistical difference was found between all osteosynthesis methods (caudal: p = 0.41; cranial: p = 0.61).

CONCLUSIONS

Symphyseal plating proved to be the osteosynthesis method with the highest rigidity. The modified SpeedBridge^™ as a semi-rigid suture construct provided statistically sufficient biomechanical stability while maintaining a minimum of symphyseal movement, consequently allowing ligamental healing of the injured joint without iatrogenic arthrodesis. Furthermore, both the criss-cross and the triangle technique displayed significant biomechanical stability without one method being superior.

A facile method for high-throughput screening of drug-eluting coatings in droplet microarrays based on ultrasonic spray deposition

Coating modification such as drug-eluting coating is one of the most important approaches for the functionalization of biomedical devices. However, the throughputs are limited in conventional coating methods and the concept of miniaturization is rarely fulfilled. A droplet microarray (DMA), as a unique high-throughput platform, can avoid cross-contamination and reduce the consumption of materials which is inherently suitable for coating research yet is difficult to apply with coating materials via traditional methods. Here, we bring up a facile method based on ultrasonic spray deposition to integrate coating materials into a DMA. Several common polymer materials were selected to fabricate a DMA, and the obtained DMA showed the ability to anchor water droplets and form specific patterns. Coating arrays with a typical sandwich structure were also prepared for the high-throughput screening of drug-eluting coatings to demonstrate the potential of the platform in coating research. This developed method is efficient and compatible and enriches the choices of materials that can be applied in DMAs.

Biomechanical stability of sacroiliac screw osteosynthesis with and without cement augmentation

BACKGROUND

Percutaneous sacroiliac (SI) screw fixation is the standard operative treatment of traumatic disruptions to the posterior pelvic ring. The technique offers good outcomes and early postoperative mobilization, which is vital in elderly patients with fragility fractures of the pelvis. While a double-screw technique has been shown to provide optimal biomechanical stability compared to a single-screw construct, anatomic variations and patient-specific characteristics may prevent the safe insertion of two SI screws. We aimed to determine whether cement augmentation of a single SI screw would provide biomechanical stability comparable to that of the double-screw technique.

METHODS

Three sacroiliac screw osteosynthesis configurations were tested on 10 human cadaveric pelvis specimens: a single cannulated screw; two cannulated screws; and a single, cement-augmented cannulated screw. Displacement and stiffness of the anterior and posterior pelvic ring after fixation with each technique were measured under axial load. Results where compared using linear regression and paired t-tests.

RESULTS

A single uncemented screw offered significantly worse stability in the anterior pelvis compared to a double-screw technique (P < 0.05) and to a single cement-augmented screw technique (P < 0.05). There was no significant difference in anterior pelvic ring stability between the single cement-augmented screw technique and the double-screw technique (P > 0.05). There was no significant difference in the stability of the posterior pelvic ring between the three techniques (P > 0.05).

CONCLUSIONS

A single cement-augmented cannulated sacroiliac screw provides biomechanical stability similar to that of a non-augmented double-screw technique in the treatment of posterior pelvic ring fractures.

Rapid build-up of high-throughput screening microarrays with biochemistry gradients via light-induced thiol-ene "click" chemistry

Microarrays have become extremely powerful experimental tools for high-throughput screening of cell behaviors in multivariate microenvironments. Herein, a microarray-based high-throughput platform with biochemistry gradients was developed using poly(limonene carbonate) (PLimC) as a substrate through thiol-ene click chemistry. ATR-IR, XPS, Raman spectrum, and water contact angle results demonstrated that the sulfhydryl molecules, including PEG (polyethylene glycol) and RGD (arginine-glycine-aspartic acid) peptide, could be grafted onto PLimC substrates, while the grafting density could be well controlled by regulating the intensity of UV irradiation. Then, microarrays with a gradient of RGD grafting density were fabricated by using UV irradiation patterned by a photomask and a gradient light filter. Adhesion experiments of smooth muscle cells and 3T3-L1 mouse embryonic fibroblast cells proved that the cell behaviors were highly determined by the RGD density. This platform puts forward a facile, high-throughput method to study the effect of biochemical signal density on cell behaviors.

Aortic aneurysm and aortic graft infection related to Mycobacterium bovis after intravesical Bacille Calmette-Guérin therapy-a case series

Background

So called “mycotic” aortic aneurysms account for only 0.7 to 1.3% of all aortic aneurysms and are commonly caused by Staphylococcus aureus and Salmonella species. Bacillus Calmette-Guérin (BCG), a live attenuated strain of Mycobacterium bovis, is part of the therapy of non-muscle-invasive bladder cancer (NMIBC).

Case presentation

We report a case series of three patients with a mycobacterial graft infection related to BCG after surgical treatment of a presumed mycotic aortic aneurysm as an extremely rare complication after NMIBC treatment. All three patients developed aortic aneurysm after BCG instillation and subsequent mycobacterial graft infection.

Conclusion

Diagnosis requires a high degree of suspicion because of its nonspecific symptoms and imaging. The pathogen is not detected by standard microbiological testing. Treatment includes triple antimycobacterial therapy and radical surgical interventions. Graft preservation may be considered if no anastomosis is involved.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01142-1.

Cementless hip revision cup for the primary fixation of osteoporotic acetabular fractures in geriatric patients

BACKGROUND

Elderly patients suffering from hip fractures are usually not able to fulfil postoperative weight-bearing restrictions. Therefore, the operative fixation construct has to be as stable as possible. Aim of the present study was to determine (1) whether a therapeutic advantage could be achieved when using hip arthroplasty to treat acetabular fractures in geriatric patients; (2) whether an acetabular revision cup would be suitable for achieving fast postoperative mobilization and full weight-bearing; and (3) when a treatment with an uncemented hip revision cup for the primary fixation of osteoporotic acetabular fractures in geriatric patients is indicated.

MATERIALS AND METHODS

The functional outcome of THA using a reconstruction cup for an acetabular fracture was evaluated in ten patients using standardized scoring instruments. In addition, an analysis of the preexisting literature referring to total hip replacement in geriatric acetabular fractures was conducted and an algorithm for standardizing the treatment approach for geriatric patients with acetabular fractures was developed.

RESULTS

The mean EQ-5D-3L quality of life score 0.7. The mean VAS Score was 58.2. The average Barthel Index was 80.0 points [range: 0-100]. The mean HHS was 72.0 points, while the MHH Score yielded an average of 63.4 points. The average AP Score was 7.5. The literature analysis showed that total hip arthroplasty could be a feasible option for geriatric acetabular fractures.

CONCLUSION

Primary hip arthroplasty using uncemented revision cup fixed with angular stable screws showed good results and is a feasible treatment option of acetabular fractures in geriatric patients. The approach is especially beneficial in patients with poor bone stock and allows postoperative full weight-bearing. The presented treatment algorithm could be a useful tool for identifying the most appropriate treatment option.

LEVEL OF EVIDENCE

IIb.

Environmental exposure enhances the internalization of microplastic particles into cells

Microplastic particles ubiquitously found in the environment are ingested by a huge variety of organisms. Subsequently, microplastic particles can translocate from the gastrointestinal tract into the tissues likely by cellular internalization. The reason for cellular internalization is unknown, since this has only been shown for specifically surface-functionalized particles. We show that environmentally exposed microplastic particles were internalized significantly more often than pristine microplastic particles into macrophages. We identified biomolecules forming an eco-corona on the surface of microplastic particles, suggesting that environmental exposure promotes the cellular internalization of microplastics. Our findings further indicate that cellular internalization is a key route by which microplastic particles translocate into tissues, where they may cause toxicological effects that have implications for the environment and human health.

Resomer C212© in vertebroplasty or kyphoplasty: A feasibility study on artificial bones with biomechanical and thermal evaluation

BACKGROUND

Vertebroplasty and kyphoplasty are now well-established methods for treating compression fractures of vertebral bodies (AO type A) as well as vertebral body metastases [1, 2, 3]. However, polymethylmethacrylate (PMMA) augmented vertebrae show fractures of subsequent vertebral bodies due to the increased stability of the augmented vertebral body [4]. Resorbable cements are currently only used experimentally. Many commercially available resorbable calcium phosphate cements do not exhibit sufficient biomechanical stability to treat vertebral body fractures [5]. Resomer C212© (Evonik Industries AG, Essen, Germany) is a slow resorbable poly-ε-caprolactone that has low melting temperatures and good biomechanical properties.

OBJECTIVE

This is a feasibility study on how the poly-ε-caprolactone Resomer C212© can be used for kypho- or vertebroplasty, what temperatures are used in the argumentation and how differences in load capacity are measurable compared to conventional PMMA cement.

METHODS

23 Sawbones© blocks (7.5 Open Cell Foam, SKU: 1522-09, laminated on both sides, 4 × 4 × 2.9 cm, Sawbones, Vashon Island, USA) were divided into three groups: 7 without augmentation, 8 augmented with PMMA cement Traumacem V+© (DePuy Synthes, West Chester, USA) and 8 augmented with Resomer C212©. Temperature measurements were made in a 37∘C water bath centrally in the block and on the top and bottom plates. This was followed by a maximum load of up to 2000 N using a universal testing machine (Instron E 10000, Instron Industrial Products, Grove City, USA).

RESULTS

In the Resomer C212© test group, the maximum average increase in temperature was 4.15 ± 4.72∘C central, 0.3 ± 0.31∘C at the top and 0.78 ± 1.27∘C at the base. In the cement test group, the average increase in temperature was 9.80 ± 10.65∘C centrally in the test block, 1.50 ± 0.73∘C at the top plate and 1.42 ± 0.66∘C and the base plate. In the axial compression test, the 7 non-kyphoplasted test blocks showed a first loading peak on average at 275.23 ± 80.98 N, a rigidity of 238.47 ± 71.01 N/mm2. In the Traumacem V+© group, the mean peak load was 313.72 ± 46.26 N and rigidity was 353.45 ± 77.23 N/mm2. The Resomer C212© group achieved a peak load of 311.74 ± 52.05 N and a stiffness of 311.30 ± 126.63 N/mm2. A compression to 50% could not be seen in any test block under the load of 2000 N. At 2000 N, Traumacem V+©'s average height reduction was 9.26 ± 2.16 mm and Resomer C212© was 10.93 ± 0.81 mm.

CONCLUSIONS

It has been shown that the application of Resomer C212© in kyphoplasty or vertebroplasty is well feasible. Thermal analysis showed significantly lower temperatures and shorter temperature application in the Resomer C212© group. In the biomechanical load up to 2000 N no significant differences could be observed between the individual groups.

The T-pod is as stable as supraacetabular fixation using 1 or 2 Schanz screws in partially unstable pelvic fractures: a biomechanical study

INTRODUCTION

Unstable fractures of the pelvis remain the predominant cause of severe hemorrhage, shock and early death in severely injured patients. The use of pelvic binders has become increasingly popular, particularly in the preclinical setting. There is currently insufficient evidence available about the stability of the pelvic binder versus supraacetabular fixation using 1 or 2 Schanz screws. We aimed to analyze the stability of the pelvic binder and supraacetabular fixateurs using either 1 or 2 Schanz screws in a cadaver model of an induced pelvic B-type fracture.

MATERIALS AND METHODS

The study was undertaken in 7 human fresh-frozen cadaveric pelvises with induced AO-type B fractures. Three stabilization techniques were compared: T-POD (pelvic bandage), supraacetabular external fixator with 1 pin on each side and external fixator with 2 pins on each side. Stability and stiffness were analyzed in a biomechanical testing machine using a 5-step protocol with static and dynamic loading, dislocation data were retrieved by ultrasound sensors at the fracture sites.

RESULTS

No significant differences in fracture fragment displacement were detected when using either the T-POD, a 1-pin external fixator or a 2-pin external fixator (P > 0.05). The average difference in displacement between the three methods was < 1 mm.

CONCLUSIONS

Pelvic binders are suitable for reduction of pelvic B-type fractures. They provide stability comparable to that of supraacetabular fixators, independently of whether 1 or 2 Schanz screws per side are used. Pelvic binders provide sufficient biomechanical stability for transferring patients without the need to first replace them with surgically applied external fixators. However, soft tissue irritation has to be taken into consideration and prolonged wear should be avoided.

LEVEL OF EVIDENCE

Level III.

Development and biomechanical evaluation of a new biodegradable intramedullary implant for osteosynthesis of midshaft fractures of small hollow bones

BACKGROUND

Up to date there is no intramedullary, biodegradable osteosynthesis commercially available to treat non-comminuted midshaft fractures of small hollow bones applying not only a stable osteosynthesis but an additional axial compression to the fracture site.

OBJECTIVE AND METHODS

Therefore we (1) designed different implant profiles and simulated the inner tension/volume using CAD. (2) Thereafter we manufactured a prototype with the best volume/tension-ratio using 70:30 poly-(L-lactide-co-D, L-lactide) (PLLA/PDLLA) and poly-ε-caprolactone (PCL) by injection moulding. Both materials are resorbable, licensed for medical use and show a slow degradation over at least one year. (3) The implants were tested in a universal testing machine (Zwick/RoellZ010) using a 3-point-bending-setup. (4) We compared the implants with different types of commercially available Ti6Al4V 6-hole 2, 3 mm-plates including interlocking systems (Leibinger Set, Stryker) (each group n= 6) using a 4-point-bending-test-setup with artificial metacarpal bones (Sawbones®).

RESULTS

The 3-point-bending-test-results showed that mean failure-force of PCL-tubes was 57.94 ± 4.28 N whereas the PLLA/PDLLA-tubes had an approximately four-fold higher value of 227.24 ± 1.87 N (p< 0.001). Additionally, the 4-point-bending-test-results showed that the maximum load of PLLA/PDLLA tubes (61.97 ± 3.58 N) was significantly higher than the strongest 6-hole metacarpal plate (22.81 ± 0.76 N) (p< 0.001).

CONCLUSION

The study showed that the new type of biodegradable, intramedullary tension-osteosynthesis made of PLLA/PDLLA is even more stable than common plate osteosynthesis in a small-hallow-bone-model. Further in vivo investigation should be performed to evaluate the surgical technique and long-term healing process of the bone and biodegradation process of the implant.

3D printing method for next-day acetabular fracture surgery using a surface filtering pipeline: feasibility and 1-year clinical results

Introduction

In orthopedic surgery, 3D printing is a technology with promising medical applications. Publications show promising results in acetabular fracture surgery over the last years using 3D printing. However, only little information about the workflow and circumstances of how to properly derive the 3D printed fracture model out of a CT scan is published.

Materials and methods

We conducted a retrospective analysis of patients with acetabular fractures in a level 1 trauma center. DICOM data were preoperatively used in a series of patients with acetabular fractures. The 3D mesh models were created using 3D Slicer (https://www.slicer.org) with a newly introduced surface filtering method. The models were printed using PLA material with FDM printer. After reduction in the printed model, the acetabular reconstruction plate was bent preoperatively and sterilized. A clinical follow-up after 12 months in average was conducted with the patients.

Results

In total, 12 patients included. Mean printing time was 8:40 h. The calculated mean printing time without applying the surface filter was 25:26 h. This concludes an average printing time reduction of 65%. Mean operation time was 3:16 h, and mean blood loss was 853 ml. Model creation time was about 11 min, and mean printing time of the 3D model was 8:40 h, preoperative model reduction time was 5 min on average, and preoperative bending of the plate took about 10 min. After 12 months, patients underwent a structured follow-up. Harris Hip Score was 75.7 points, the Modified Harris Hip Score 71.6 points and the Merle d’Aubigne Score 11.1 points on average.

Conclusions

We presented the first clinical practical technique to use 3D printing in acetabular fracture surgery. By introducing a new surface filtering pipeline, we reduced printing time and cost compared to the current literature and the state of the art. Low costs and easy handling of the 3D printing workflow make it usable in nearly every hospital setting for acetabular fracture surgery.

Tape suture for stabilization of incomplete posterior pelvic ring fractures-biomechanical analysis of a new minimally invasive treatment for incomplete lateral compression pelvic ring fractures

Background

Incomplete lateral compression fractures (including AO Type B2.1) are among the most common pelvic ring injuries. Although the treatment of choice remains controversial, sacroiliac (SI) screws are commonly used for the operative treatment of incomplete lateral compression fractures of the pelvic ring. However, the disadvantages of SI screws include the risk of nerve root or blood vessel injury. Recently, tape sutures have been found useful as stabilizing material for the treatment of injuries of the syndesmosis, the rotator cuff and knee ligaments. In this current study, we aimed to test the biomechanical feasibility of tape sutures to stabilize the pelvis in the setting of AO Type B2.1 injury.

Methods

Six human cadaveric pelvises underwent cyclic loading to compare the biomechanical stability of different osteosynthesis methods in a B2.1 fracture model. The methods tested in this experiment were a FiberTape® suture and the currently established SI screw. A 3D ultrasound tracking system was used to measure fracture fragment motion. Linear regression was used to model displacement and stiffness at the posterior and anterior pelvic ring.

Results

At the posterior fracture site, the FiberTape® demonstrated similar displacement (2.2 ± 0.8 mm) and stiffness (52.2 ± 18.0 N/mm) compared to the sacroiliac screw (displacement 2.1 ± 0.6 mm, P >  0.999; stiffness 50.8 ± 13.0 N/mm, P > 0.999).

Considering the anterior fracture site, the FiberTape® again demonstrated similar displacement (3.8 ± 1.3 mm) and stiffness (29.5 ± 9.0 N/mm) compared to the sacroiliac screw (displacement 2.9 ± 0.8 mm, P = 0.2196; stiffness 37.5 ± 11.5 N/mm, P = 0.0711).

Conclusion

The newly presented osteosynthesis, the FiberTape®, shows promising results for the stabilization of the posterior pelvic ring in AO Type B2.1 lateral compression fractures compared to a sacroiliac screw osteosynthesis based on its minimal-invasiveness and the statistically similar biomechanical properties.

Evaluation of urinary selenium as a biomarker of human occupational exposure to elemental and inorganic selenium

PURPOSE

Selenium (Se) is an essential trace element, which however, exhibits a narrow safe range of intake. Selenium also occurs at several workplaces, which results in an inhalative selenium exposure of the employees. Thus, an efficient exposure assessment strategy is demanded. The most established parameter, selenium in plasma, mostly consists of protein-bound selenium. This study aimed to investigate urinary total selenium (Se-U) as an additional biomarker of recent human occupational exposure to elemental and inorganic selenium.

METHODS

Pre- and post-shift urine samples from employees with exposure to selenium-containing dust were analyzed to total selenium and compared with Se levels in urine samples from controls without occupational exposure to selenium as well as correlated with the recent ambient Se exposure by personal air monitoring.

RESULTS

Se-U in post-shift samples was considerably increased compared to the levels in pre-shift samples as well as to the controls. However, Se-U in pre-shift urine was elevated compared to the Se-U in controls too. Se-U in post-shift urine and even better the shift increment in Se-U correlated with the air exposure of the present shift. A rough estimation by Se-U shift increment and external exposure accounted for an inhalative resorption rate of about 1%.

CONCLUSION

Our data indicate that Se-U can display the exposure. Pre-shift Se-U levels may be based on previous exposure and indicate a slow urinary elimination kinetics. The results hint for a rather low resorption rate of selenium and inorganic selenium compounds via the lung.

Modified less invasive anterior subcutaneous fixator for unstable Tile-C-pelvic ring fractures: a biomechanical study

BACKGROUND

Operative procedures for unstable pelvic ring fractures remain controversially discussed. Minimally invasive treatment options for pelvic ring fractures have several benefits for the patient. But they can also provide disadvantages. Anterior subcutaneous pelvic fixation (INFIX) has shown promising biomechanical results in pelvic ring fractures, but there is a high complication rate of nerve injuries. An additional screw to the INFIX seems to be more stable. The aim of this study is to compare biomechanical stability of a new modified unilateral INFIX fixing the unilateral injured pelvic ring with the standard INFIX.

METHODS

24 composite synthetic full pelvises were used in this study. 4 groups each with a number of six pelvic specimens were randomly assigned. A C1.3-type pelvic fracture was made with an osteotomy of the sacrum and an osteotomy of the anterior pelvic ring. Fracture fixation was performed within the four groups: (1) unilateral INFIX, (2) "extended" unilateral INFIX + additional pubic ramus pedicle screw, (3) bilateral INFIX, (4) "extended" bilateral INFIX + additional pubic ramus pedicle screw. All specimens were cyclic loaded with 200 N until maximum of 300 N. Distance/dislocation of the fracture fragments were detected with 3D-ultrasound measuring system. Stiffness was calculated.

RESULTS

Extended unilateral INFIX showed the lowest mean dislocation. Lowest rotational stability was displayed by the standard bilateral INFIX. A significant difference (P = 0.04) was shown between the extended unilateral INFIX and the "standard" bilateral INFIX in terms of rotational stability. Extended unilateral INFIX showed significantly improved stability of anterior fracture dislocation (P = 0.01) and unilateral INFIX showed the highest rotational stiffness. Anterior fixation stiffness of the unilateral INFIX was significantly improved using an additional symphysis/pubic ramus screw (P = 0.002).

CONCLUSION

Extended unilateral INFIX (+ additional pubic ramus pedicle screw) is a feasible minimally invasive treatment for anterior pelvic ring fractures. Higher stability and lower probability of bilateral nerve damage is provided by the extended unilateral INFIX compared to the standard bilateral INFIX.

Radiographic cortical thickness parameters as predictors of rotational alignment in proximal femur fractures: A cadaveric study

Radiographic assessment tools such as the cortical step sign (CSS) or the diameter difference sign (DDS) aim to identify clinically relevant rotational malalignment after long bone fracture fixation. We aimed to analyze the effect of rotational malalignment on CSS and DDS parameters in a subtrochanteric fracture model and to construct a prognostic model to identify clinically relevant rotational malalignment. A subtrochanteric transverse osteotomy was set in human femora. Rotation was set stepwise from 0° to 30° in internal and external rotation. Images were obtained using a C-arm and transferred for measuring the medial cortical thickness (MCT), lateral cortical thickness (LCT), femoral diameter (FD) in AP and the anterior cortical thickness (ACT) as well as the posterior cortical thickness (PCT) and the FD of the proximal and the distal main fragment. There were significant differences between the various levels of rotation for each of the absolute values of the evaluated variables. MCT, PCT and FD (AP & lat.) were the most affected parameters. In internal rotation, the MCT, PCT and the FD were the most affected variables. The parameters with the highest correlation with femoral rotation were ACT, PCT and FD. A model combining ACT, LCT, PCT and FD AP was most suitable model in identifying rotational malalignment. The best prediction of clinically relevant rotational malalignment was obtained with the FD and the PCT. The CSS and the DDS are promising tools for detecting rotational deformities of the proximal femur and should be used intra- and postoperatively. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Minimally invasive screw fixation is as stable as anterior plating in acetabular T-Type fractures - a biomechanical study

INTRODUCTION

Operative treatments of T-type acetabular fractures are challenging surgical procedures. Open reduction and internal fixation is the standard method for the operative management of these fractures, however this is associated with high blood loss, long hospital stay and longer rehabilitation. Anterior subcutaneous pelvic fixation (internal fixation=INFIX) and retrograde pubic screw fixation have shown promising results in minimally invasive treatment of pelvic ring fractures. For T-type acetabular fractures, however, minimally invasive treatment concepts are still rare. Therefore we performed a mechanical in vitro study to: - investigate the potential favorability of minimally invasive treatment options over the already established open anterior locking plate osteosynthesis of acetabular T-fractures regarding biomechanical stability and post-surgical stiffness; - explore the biomechanical feasibility of the INFIX; - assess its potential ability to reduce the anterior acetabular column.

HYPOTHESIS

A minimally invasive treatment of acetabular T-type fractures is biomechanically equivalent to an open anterior plate osteosynthesis.

METHODS

Twenty-four synthetic hemipelvis specimens with a T-type acetabular fracture were divided in four groups. A posterior column screw was placed in every pelvis of every group. The anterior column was fixed with: - anterior column screw; - anterior column screw incl. INFIX; - INFIX alone; - 14-hole angular stable locking plate (standard fixation method). Displacement of the anterior column was reduced in group 2+3 using the INFIX. All specimens were cyclically loaded with 200N until a maximum of 600N. Movement/displacement of the fracture fragments were detected with a 3D-ultrasound measuring system. Displacement (mm) and Stiffness (N/mm) of the construction were analyzed.

RESULTS

Statistical assessment showed no significant differences between the four fixation types (p>0.05). The 14-whole locking plate (group 4) displayed the overall highest stability with a displacement of 1.3±0.04mm and stiffness of 76.3±2.4N/mm. Anterior screw fixation (group 1) proved to be the minimally invasive fixation method with the least displacement and highest stiffness (1.5±0.2mm, 68.3±6.8N/mm). The combination of an INFIX and an anterior column screw (group 2), showed a mean stiffness of 62.1±6.0N/mm and a mean displacement of 1.7±0.2mm. INFIX only (group 3) presented a displacement of 1.6±0.1mm and a stiffness of 64.5±4.5N/mm.

DISCUSSION

Minimally invasive fixation techniques for T-type acetabular fractures show promising biomechanical stability in non- or slightly displaced fractures. Furthermore, INFIX could be a feasible tool for the reduction of the anterior acetabular column.

LEVEL OF EVIDENCE

III, case control prospective experimental study.

Urine neutrophil gelatinase-associated lipocalin predicts outcome and renal failure in open and endovascular thoracic abdominal aortic aneurysm surgery

Urine neutrophil gelatinase–associated lipocalin (uNGAL) has been evaluated as a biomarker for AKI detection and adverse outcome in open and endovascular thoracoabdominal aortic aneurysm surgery. This observational, retrospective study included 52 patients. UNGAL was measured peri-operatively (48 h) and correlated with AKI requiring dialysis, tracheotomy and adverse outcome. Mean patients’ age was 64.5 years. A total of 26.9% (n = 14) developed AKI, and 21.1% (n = 11) required dialysis, tracheotomy rate was 19.2% (n = 10) and in-hospital mortality rate was 7.6% (n = 4). uNGAL levels were related to AKI requiring dialysis at ICU (p = 0.0002), need for tracheotomy at baseline and admission on ICU (p = 0.0222, p = 0.0028, respectively), as well as adverse discharge modality (p = 0.0051, p = 0.0048, respectively). Diagnostic quality was good for uNGAL levels at admission to ICU regarding AKI requiring dialysis (sensitivity: 81.8% [48.2–97.7]; specificity: 87.8% [73.8–95.9]; area under the curve (AUC): 0.874 [0.752–0.949]). The diagnostic quality of uNGAL was favorable for the prediction of tracheotomy (sensitivity: 70.0% [34.8–93.3]; specificity: 83.3% [68.6–93.0]; AUC: 0.807 [0.674–0.903]) and adverse discharge (sensitivity: 77.8% [40.0–97.2]; specificity: 83.7% [69.3–93.2]; AUC: 0.817 [0.685–0.910]). uNGAL may be valuable as an post-operative predictor of AKI and adverse outcome after open and endovascular TAAA repair.

[Diagnostic and Treatment Strategies in Morel-Lavallee Lesions in the Spinal Column and Pelvis]

BACKGROUND

The Morel-Lavallée lesion is one of the concomitant soft tissue lesions of pelvic fractures. Its role in spine fractures and its treatment in combination with osteosynthesis of pelvic or spine fractures have not yet been determined. The aim of this study was to analyse the best diagnostic and treatment options of both spine and pelvic fractures combined with Morel-Lavallée lesions (MLL).

METHODS

An analysis of the literature was performed via PubMed and Medline. This revealed a total of 197 studies and case reports. After analysing the literature, 19 studies/case reports met our inclusion criteria.

RESULTS

There are several diagnostic options for MLL, including ultrasound, computed tomography or MRI. In spinal and pelvic lesions, ultrasound is capable of detecting MLL. Some authors tend to perform open debridement of the MLL, whereas others recommend percutanous treatment. Open debridement and vacuum-assisted closure are recommended in late diagnosed MLL, where primary suture of the soft tissue is impossible. Fracture fixation should be performed simultaneously to treatment of the MLL. Broad-spectrum cephalosporins combined with an aminoglycoside or piperacilline/tazobactam should be initiated.

CONCLUSION

Radical debridement and drainage are recommended, especially when MLL is diagnosed late. Repeated ultrasound examinations should be performed of the surrounding soft tissue of the fracture. When MLL is diagnosed within 2 days, percutanous fracture and MLL treatment should be performed. After more than 2 days, both fracture and MLL should be treated with open debridement, open fracture fixation and primary suture if possible.

IKZF1 expression is a prognostic marker in newly diagnosed standard-risk multiple myeloma treated with lenalidomide and intensive chemotherapy: a study of the German Myeloma Study Group (DSMM)

Lenalidomide is an immunomodulatory compound with high clinical activity in multiple myeloma. Lenalidomide binding to the Cereblon (CRBN) E3 ubiquitin ligase results in targeted ubiquitination and degradation of the lymphoid transcription factors Ikaros (IKZF1) and Aiolos (IKZF3) leading to growth inhibition of multiple myeloma cells. Recently, Basigin (BSG) was identified as another protein regulated by CRBN that is involved in the activity of lenalidomide. Here, we analyzed the prognostic value of IKZF1, IKZF3, CRBN and BSG mRNA expression levels in pretreatment plasma cells from 60 patients with newly diagnosed multiple myeloma uniformly treated with lenalidomide in combination with intensive chemotherapy within a clinical trial. We found that IKZF1 mRNA expression levels are significantly associated with progression-free survival (PFS). Patients in the lowest quartile (Q1) of IKZF1 expression had a superior PFS compared with patients in the remaining quartiles (Q2-Q4; 3-year PFS of 86 vs 51%, P=0.01). This translated into a significant better overall survival (100 vs 74%, P=0.03). Subgroup analysis revealed a significant impact of IKZF1, IKZF3 and BSG expression levels on PFS in cytogenetically defined standard-risk but not high-risk patients. Our data suggest a prognostic role of IKZF1, IKZF3 and BSG expression levels in lenalidomide-treated multiple myeloma.

Bio-based polycarbonate as synthetic toolbox

Completely bio-based poly(limonene carbonate) is a thermoplastic polymer, which can be synthesized by copolymerization of limonene oxide (derived from limonene, which is found in orange peel) and CO2. Poly(limonene carbonate) has one double bond per repeating unit that can be exploited for further chemical modifications. These chemical modifications allow the tuning of the properties of the aliphatic polycarbonate in nearly any direction. Here we show synthetic routes to demonstrate that poly(limonene carbonate) is the perfect green platform polymer, from which many functional materials can be derived. The relevant examples presented in this study are the transformation from an engineering thermoplastic into a rubber, addition of permanent antibacterial activity, hydrophilization and even pH-dependent water solubility of the polycarbonate. Finally, we show a synthetic route to yield the completely saturated counterpart that exhibits improved heat processability due to lower reactivity.

Sacroiliac Coalition: First Description and Report of a Successful Resection

Study Design Case report. Objective This report describes the first case of a sacroiliac coalition, its clinical features, the diagnostic difficulties, and the surgical treatment chosen in this case. Methods A 33-year-old man presented to our outpatient clinics complaining of severe left-sided low back pain with an intermitted nondermatomal radiation into the left thigh. The only abnormality on a pelvic radiograph was a coin-size, faint hyperdensity, which was almost overlooked. Subsequent computed tomography (CT) and magnetic resonance imaging (MRI) confirmed two bridging bone spurs on the anterior surface of the left joint with a fibrous interruption at the apex. After the conservative treatment failed, a surgical treatment was offered to the patient. The coalition was resected via an anterior retroperitoneal approach and through the tissue plane between the psoas and the iliacus muscles. A histopathologic examination was performed and confirmed the diagnosis of a coalition. Results The patient's pain resolved immediately after surgery. After 8 months, a follow-up CT scan showed complete removal of the coalition without any signs of recurrence, and at 12 months' follow-up, the patient remained pain-free. Conclusions This is the first published case of a sacroiliac coalition. The only sign of this rare condition on the plain radiographs was very easy to miss. As has been discussed in the literature, CT and MRI are important in the differential diagnostics of such lesions. The histopathologic findings included that of a fibrous bar, confirming the diagnosis, which is further corroborated by the complete resolution of the symptoms.

[The Compression Syndrome of Lumbar Arteries - Case Report of a Rare Disease Pattern]

STUDY DESIGN

We present a monocentric analysis of the lumbar artery compression syndrome (LACS) in the form of a case report.

OBJECTIVES

Literature information was collected about the symptoms, diagnosis and treatment of this rare disorder in the context of the existing data.

METHODS

The current medical literature includes only one report about three cases of LACS, collected over 20 years in France and Germany. We compared these cases with the experience of the European Vascular Center Aachen-Maastricht.

RESULTS

The symptoms of this rare disorder are dominated by reversible, motion-dependent paralysis of the legs. Compression of the right lumbar arteries by muscular fibres or connective tissue is a fundamental cause.

CONCLUSION

Surgical treatment, which means decompression of the lumbar arteries via a thoracolaparotomy, is an appropriate therapy with few complications and good long-term results.

CT-guided sacroiliac percutaneous screw placement in unstable posterior pelvic ring injuries: accuracy of screw position, injury reduction and complications in 71 patients with 136 screws

BACKGROUND

Sacroiliac-percutaneous-screw-placement (SPSP) for unstable-posterior-pelvic-ring-injuries (UPPRI) might be associated with severe neurovascular complications because of screw-mal-position. The aim of the present study was to analysis the effectivity of computer-tomography-guided (CTG)-SPSP including accuracy of screw-placement, quality of injury-reduction and documentation of perioperative-complications. Additionally, procedure-dependent radiation-dose and outcome should be analysed.

METHODS

A consecutive cohort of 71 patients with UPPRI was operated by CTG-SPSP at a single trauma level 1 hospital. 136 sacroiliac screws were inserted to S1 and S2. Postoperatively, by the use of a computerised-radiologic-work-station all screws were visualised three-dimensionally. Their distancesmin to the sacral-borders in anterior-posterior and cranio-caudal direction as well as to the neuroforamen S1/S2 were determined. After CTG-SPSP, injury-dislocation in anterior-posterior and cranio-caudal direction was quantified. Local and general complications were documented during the 30-day-period. In 55 patients (77.5%) a follow-up-investigation (29.1±19.1 months) was performed.

RESULTS

132 screws (97.1%) were placed completely intraosseous, 3 screws (2.2%) perforated up to 1.0 mm (n(S1)=one screw; n(S2)=two screws), and one screw (0.7%) extended 2.2 mm into the S2-neuroforamen without contact to neural structures. Postoperative dislocationanterior-posterior was 1.3±0.9 mm and dislocationcranio-caudal 1.5±0.9 mm. No procedure-associated-complication was observed. Operation time showed a significant "learning curve" during the six-year study period (initially: 88.6±60.3 min; finally: 44.3±24.6 min). Perioperative effective-radiation-dose for patientsmale was 5.9±3.1 mSv and for patientsfemale 8.7±4.5 mSv. All injuries healed and 33 patients (46.5%) had metal removal after 11.0 (±4.9) months. Only two (5.0%) out of 40 patients complained persistent UPPRI-related pain so they were not able to restart work.

CONCLUSIONS

The CTG-SPSP is a safe procedure for UPPRI-stabilisation especially in S1 but also in S2. Injury reduction was excellent and no procedure associated complications were observed.

What predicts outcome after recanalization of chronic venous obstruction: hemodynamic factors, stent geometry, patient selection, anticoagulation or other factors?

In this review we evaluated the effect of different suggested factors associate with the outcome after recanalization of chronic venous obstruction (CVO).

Hemodynamic factors:

Based upon literature no clear suggestions can be made to identify the risk of stent occlusion in association with the hemodynamic effects. However it is evident that ensuring optimal in- and outflow of the stented tract is key in maintaining the patency.

Patient selection:

Noninvasive imaging modalities are used to divide patients in three subgroups based on the place and extension of post-thrombotic changes. Moreover it should be noted that AV fistula in selected patients can reduce the risk of thrombosis or re-occlusion.

Geometry:

Excessive oversizing of the stent and stent compression from outside are considered to be associated with stent occlusion. Additionally, overlapping rigid stents, unnatural angel between stents and in-stent kinking are other geometrical factors related to worse outcome after venous recanalization.

Anticoagulation:

Adequate peri-and postoperative anticoagulation has a crutial role in stent patency. There is no data regarding the duration of anticoagulation therapy and recommendations vary between 6 weeks to 6 months.

Result:

impaired inflow or outflow, presence of a hypercoagulability, total number of treated segments and use of stents designed for implantation in arterial system are associated with decreased stent patency.

Anatomic changes of target vessels after fenestrated and branched aortic aneurysm repair

AIM

Objective of this study was to evaluate the anatomic changes of the stented target vessels after endovascular repair of complex aortic aneurysms.

METHODS

Between July 2011 and December 2013, 53 aortic aneurysms were treated in our department with fenestrated and branched stent-graft devices. Forty-two of these patients were pre- and postoperatively scanned with a high resolution computer tomography (CT) (Cook Zenith® fenestrated or branched, Australia Pty. Ltd., Brisbane, Australia: N.=19; AnacondaTM fenestrated, Vascutek, Glasgow, Scotland, UK: N.=23). The other 11 out of the 53 patients did not receive a CT scan, because of a pre-existing renal failure. In the CT scans we retrospectively evaluated the anatomic vessel deviation at the origin of the target vessel and the vessel shift distal to the stent. For the first measurement the CT scans were loaded into OsiriX MD®, and the pre- and postoperative angles of the target vessels were measured and subtracted. For matching, the CT-scans were normalized at vertebral body lumbar 2. The second measured angle was the maximal measured angle distal to the target vessel stent-graft.

RESULTS

Altogether, 113 target vessels were stented (celiac trunk [CT] 15, superior mesenteric arteries [SMA] 26, renal arteries [RA] 72), with 97 balloon-expandable PTFE stents: 90 Atrium V12 (Maquet Getinge group, Hudson, NH, USA), 7 BeGrafts (Bentley InnoMed, Hechingen, Germany) and 16 self-expandable fluency PTFE stents (Bard, Karlsruhe, Germany). The mean anatomic deviation at the target vessel origin was 28±17.3 and the mean vessel shift distal to the stent was 36.3±18.8. There were no significant differences between the main device and the target vessel stent types.

CONCLUSION

Fenestrated and branched stent-graft solutions for aortic aneurysm repair induce changes of the target vessel anatomy. We did not observe significant differences between the several devices.

A new shunting concept to prevent lower limb ischemia/reperfusion injury in prolonged fenestrated stent-graft procedures

AIM

Complex endovascular procedures to treat thoracoabdominal aortic aneurysms (TAAA) can be time consuming and therefore comprise the risk of lower limb ischemia with subsequent reperfusion injury and compartment syndrome. Aim of this study was to evaluate a new protective method to prevent these postoperative problems.

METHODS

In order to maintain blood perfusion to both legs during prolonged endovascular aortic procedures we developed a shunting technique with two additional 7 French (Fr) sheaths in both superficial femoral arteries. We evaluated the perfusion technique in 5 patients with fenestrated endovascular aortic aneurysms repair (FEVAR). First, we measured the flow in the 7 Fr sheaths; second, we clinically controlled the lower limb for developing compartment syndrome. Third we measured creatinine kinase (CK) as marker for postoperative muscular damage.

RESULTS

In 5 male patients (median age 77, range 59-80 years) undergoing endovascular TAAA repair, the perfusion technique was feasible. The median flow per catheter was 102 mL/min (range 61-156.5 mL/min) and monophasic with a mean arterial blood pressure of 71 mmHg (range 56-82 mmHg). No patient developed a compartment syndrome. The CK levels were only lightly elevated.

CONCLUSION

This simple perfusion technique allows adequate lower limb perfusion during prolonged complex endovascular aortic procedures.

Late rupture after EVAR: a new trend?

AIM

Endovascular aortic repair (EVAR) is an adequate therapy for abdominal aortic aneurysms (AAA). Late aortic ruptures caused by endoleaks after EVAR still remain a critical issue. The aim of this study was to assess the causes of ruptured aortic aneurysms after EVAR in a single center study.

METHODS

All patients, who were treated in our University hospital with a ruptured juxtra- or infrarenal AAA between January 2011 and October 2013, were included in this retrospective analysis.

RESULTS

Thirty patients with ruptured infra- or juxtrarenal aneurysms were treated in this time frame. Six out of these 30 patients had previous EVAR repair. The median maximal aneurysm diameter of these post-EVAR patients was 82 (75-95) mm. The median time between primary EVAR and rupture was 42.5 (14-99) months. Three patients with type Ia endoleaks were treated by stent removal and conventional aortic reconstruction. In two patients with type II endoleak the bleeding was controlled by occluding the back bleeding lumbar arteries. One type III endoleak was sealed by an additional stent-graft implantation into the right iliac artery.

CONCLUSION

We observed a considerable number of patients with a ruptured AAA after EVAR. Surprisingly, we observed two ruptured aneurysms due to type II endoleaks.

Intentional left subclavian artery coverage without revascularization during TEVAR

At present, endovascular therapy is a well-established treatment for different types of thoracic aortic pathologies. There is growing evidence, that thoracic endovascular aortic repair (TEVAR) has advantages over open repair with regard to perioperative morbidity and mortality in the treatment of thoracic aortic aneurysms. However, in up to 50% of TEVAR procedures the proximal end of the stent-graft will (partly) cover the origin of the left subclavian artery (LSA) in order to achieve a save sealing zone. Intracranial stroke and paraplegia are feared complications and might be associated with LSA exclusion from the circulation. Unfortunately, no reliable technique is available to assess the individual risk of stroke and paraplegia in case of LSA coverage, so that the indication for LSA revascularization continues to be matter of assuming and guessing. The quality of available evidence on necessity or superfluity to revascularize the LSA is very low and studies report, to some extent, controversial outcome after intentional LSA coverage. In the light of the devastating consequences for patients in case of neurological complications due to LSA coverage the question of prophylactic LSA revascularization remains a significant problem which is elucidated and discussed in this manuscript.

Thoracoabdominal aneurysms and changes in adjacent vertebral bodies

AIM

The aim of this study was to assess if chronic intermittent pressure of a thoracoabdominal aortic aneurysm (TAAA) induces structural changes in vertebral bodies and if eroded vertebral bones can still be found after the extermination of syphilis.

METHODS

A retrospective analysis of computed tomography (CT) scans of patients with TAAA was performed. In the anatomical regions were the TAAA was in close contact with the vertebral bodies, the vertebral body alteration was distinguished into 4 categories. Category 0: no changes; 1: discrete changes, minimal asymmetry; 2: obvious asymmetry of the vertebral body with sustained cortical layer; 3: severe destruction of the vertebral body with loss of the cortical layer.

RESULTS

Eighty-six CT scans of patients (mean age 63; range 25-82 years) with TAAA pathology were examined (24 female, 62 male). The mean aneurysm diameter was 6.5 cm (4.3-14 cm). The results for scoring were: category 0: 33 patients; category 1: 46 patients; category 2: 5 patients and category 3: 2 patients. One of the category 3 patients suffered from acute spinal cord compression with complete paraplegia. In total, 62% of patients showed some degree of changes at vertebral bodies adjacent to the TAAA.

CONCLUSION

Intermittent pressure by either dissecting or non-dissecting TAAAs may induce structural changes in the vertebral bodies of the spine. Severe destruction of the bone is a rare, but existing complication.

[Aortic aneurysm 2012: open, hybrid or total endovascular repair?]

During the past two decades, minimally invasive endovascular procedures have changed therapeutic strategies. Such techniques have now become the method of choice for practically all vascular and aortic pathologies. This development is especially apparent in the treatment of aortic aneurysms. The purpose of this report is to provide a critical review about the current standard of care of abdominal and thoracic aorta based on an electronic Medline literature search. For elective infrarenal aneurysms, endovascular aneurysm repair (EVAR) has become a widely accepted alternative to open repair in cases with appropriate morphology. Currently, fenestrated (FEVAR) or branched endografts offer promising short- and mid-term results in juxtarenal aneurysms, however, these techniques are complex, technically challenging, and expensive. The alternative chimney or sandwich graft technique are becoming more common because they are feasible using standard endografts. Thoracic endovascular aortic repair (TEVAR) is already the gold standard for some descending pathologies. Complex thoracoabdominal aneurysms still require open surgery in centres of excellence, whereby, total endovascular repair or hybrid procedures have proved to be feasible in such specialist centres for selected patients.

Primary and secondary amputation in critical limb ischemia patients: different aspects

The TASC II working group reports on primary amputation incidence rates vary between 12 and 50 per 100,000 per year. The primary amputation rate does not only depend on co-morbidities like diabetes and PAD, but also on local factors like the regional availability of vascular surgeons and interventional radiologists and their case load. Further-more, several studies could show that increasing revascularisation rates have drastically reduced amputation rates in the US, with a 50% decrease in amputation rates during a 10 year study period and a corresponding increase in surgical and endovascular revascularisation rates. An analysis of national and state US databases confirmed a drop in major amputations and open surgical revascularisations, in favour of an increase in endovascular interventions. The same study observed an increase in minor amputations during the same period. However, it remains unclear whether this trend is a consequence of the increased usage of endovascular procedures in high-risk patients who are unfit for open surgery or of earlier endovascular intervention in less critical lesions. This review gives an overview of the incidence, indication, amputation-level finding and outcome of major amputations performed in critical limb ischemia (CLI) patients.