Advances in musculoskeletal imaging and their clinical utility in the early diagnosis of spondyloarthritis

Interest in imaging ankylosing spondylitis (AS) and related spondyloarthropathies has increased in recent years. MRI is regarded as the most sensitive imaging modality to detect early inflammatory lesions in the sacroiliac joints and in the spine. Standard radiography plays a major role in evaluating potential disease-modifying properties of the recently introduced, symptomatically effective anti-tumor necrosis factor-alpha agents. Various radiographic scoring methods have been developed to assess and monitor spinal structural damage in AS. The modified stoke ankylosing spondylitis spine score is the method of choice based on its sensitivity to change. MRI is emerging as a useful tool to detect AS early, but this remains a challenge. Recent progress in MR technology with the advent of whole body MRI has expanded the potential role of imaging in AS. Further data are needed before MRI can replace radiographs for earlier diagnosis of AS.

Whole body MR imaging in ankylosing spondylitis: a descriptive pilot study in patients with suspected early and active confirmed ankylosing spondylitis

Background

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis.

The goal of this study was to assess the frequency and distribution of abnormalities on whole body MR imaging in patients with suspected early ankylosing spondylitis and with active confirmed ankylosing spondylitis.

Methods

Ten patients with suspected early ankylosing spondylitis and ten patients with confirmed ankylosing spondylitis were enrolled. On an 18-channel MR system, coronal and sagittal T1 weighted and STIR sequences were acquired covering the entire spine, sacrum, anterior chest wall, shoulder girdle, and pelvis. The total examination time was 30 minutes.

Results

In both groups inflammatory lesions of the lower thoracic spine were frequent (number of patients with suspected early/confirmed ankylosing spondylitis: 7/9). In confirmed ankylosing spondylitis the upper thoracic spine (3/6) and the lumbar spine (4/8) were more commonly involved. The inferior iliac quadrant of the sacroiliac joints was frequently altered in both groups (8/8). The superior iliac (2/5), inferior sacral (6/10) and superior sacral (3/6) quadrants were more frequently affected in confirmed ankylosing spondylitis. Abnormalities of the manubriosternal joint (2/4), the sternoclavicular joints (1/2) and hip joint effusion (4/3) were also seen.

Conclusion

In both suspected early ankylosing spondylitis and confirmed ankylosing spondylitis, whole body MR examinations frequently demonstrate inflammatory lesions outside the sacroiliac joints. These lesions are similarly distributed but occur less frequently in suspected early compared to confirmed ankylosing spondylitis. Due to the small sample size in this pilot study these results need to be confirmed in larger studies with this emerging technique.

Does Chemotherapy Impair the Bone Healing and Biomechanical Stability of Vascularized Rib and Fibula Grafts?

The purpose of this study was to observe the impact of chemotherapy on the healing and biomechanical properties of vascularized bone grafts. Ten male beagle dogs were divided into two experimental groups: a chemotherapy group (CH) and control group (C). Group CH received adjuvant and neo-adjuvant chemotherapy. Each animal of both groups underwent the following operative procedures. The 5th and 7th rib were removed and replaced by vascularized pedicle transfers of the adjacent 4th and 8th rib. Additionally, a free fibular flap was elevated and retransferred to the same anatomic position. The rate of bony union on plain x-ray was 100 percent in group C, 30 percent in the vascularized rib, and 80 percent in the fibula grafts of group CH. Microangiography demonstrated no avascular bone segments in group C and in the fibula flaps of group CH. The vascularized ribs of group CH presented with 20 percent avascular bone segments. Biomechanical tests focusing on the durability of the vascularized grafts against bending and torsion forces demonstrated a reduction of the average maximum bending times by 17 percent and 23.9 percent compared to the controls ( P < 0.05). The twisting times were reduced by 13.8 percent (n.s.) and 32.5 percent ( P < 0.05). The data demonstrated a clear worsening in bone healing and stability after simulated adjuvant and neo-adjuvant chemotherapy. Thus, a large animal model was established for the further determination of the effects of chemotherapy on different vascularized bone transfers.

Impact of radiation therapy on healing and stability of vascularized bone grafts in a dog model

The purpose of the study was to observe the impact of radiation therapy on healing and biomechanical properties of vascularized bone grafts, and thus to establish an appropriate large animal model. Ten male beagles were divided into two experimental groups: radiation (R) and control (C). The left 5th to 7th ribs of the animals of group R were irradiated 3 and 2 weeks preoperatively, using a dose of 8 Gy each time. Each animal of both groups underwent the following operative procedures. The 5th and 7th ribs were removed, and the 5th rib was replaced by a vascularized pedicle transfer of the 4th rib. The 7th rib was reconstructed using a pedicle transplant of the 8th rib. The 5th and 7th ribs were used as nonvascularized bone grafts to replace the donor sites of the 4th and 8th ribs, respectively. Group R received two further irradiation cycles 2 and 3 weeks postoperatively. The vascularized rib grafts of group R demonstrated a higher number of delayed unions in plain x-rays and avascular bone segments in microangiography than the control group. The presence of vital osteocytes in histology was not significantly different between groups. Biomechanical tests focusing on the durability of vascularized ribs against bending and torsion forces demonstrated a reduction of average maximum bending moments by 56.6% after radiation compared to controls (P < 0.05). Twisting moments were reduced by 47.6% (P < 0.05). The data demonstrate a significant worsening in bone healing and stability after pre- and postoperative radiation therapy to the wound bed and bone grafts. Thus, a large animal model is established for further determination of different strategies of radiotherapy in combination with vascularized bone transfers.

Conversion of a CHO cell culture process from perfusion to fed-batch technology without altering product quality

During the development of a new drug product, it is a common strategy to develop a first-generation process with the aim to rapidly produce material for pre-clinical and early stage clinical trials. At a later stage of the development, a second-generation process is then introduced with the aim to supply late-stage clinical trials as well as market needs. This work was aimed at comparing the performance of two different CHO cell culture processes (perfusion and fed-batch) used for the production of a therapeutically active recombinant glycoprotein at industrial pilot-scale. The first-generation process was based on the Fibra-Cel packed-bed perfusion technology. It appeared during the development of the candidate drug that high therapeutic doses were required (>100mg per dose), and that future market demand would exceed 100 kg per year. This exceeded by far the production capacity of the first-generation process, and triggered a change of technology from a packed-bed perfusion process with limited scale-up capabilities to a fed-batch process with scale-up potential to typical bioreactor sizes of 15m(3) or more. The productivity per bioreactor unit volume (in product m(-3)year(-1)) of the fed-batch process was about 70% of the level reached with the first-generation perfusion process. However, since the packed-bed perfusion system was limited in scale (0.6m(3) maximum) compared to the volumes reached in suspension cultures (15m(3)), the fed-batch was selected as second-generation process. In fact, the overall process performance (in product year(-1)) was about 18-fold higher for the fed-batch compared to the perfusion mode. Data from perfusion and fed-batch harvests samples indicated that comparable product quality (relative abundance of monomers dimers and aggregates; N-glycan sialylation level; isoforms distribution) was obtained in both processes. To further confirm this observation, purification to homogeneity of the harvest material from both processes, followed by a complementary set of studies (e.g. full physico-chemical characterization, assessment of in vitro and in vivo bioactivity, comparative pharmacokinetics and pharmacodynamics studies in relevant species, etc.) would be required. Finally, this illustrates the need to fix the production process early during the development of a new drug product in order to minimize process conversion efforts and to shorten product development time lines.

Verletzungen des kraniozervikalen Übergangs

Injuries to the upper cervical spine (C0-C2) play a major role in surgical treatment of traumatic sequelae in the entire cervical spine. Even though the number of such operations has increased in recent years, there are no clear treatment recommendations for most types of cervical spine injuries. In view of the wide range of injury types and the correspondingly large number of treatment options, this review focuses mainly on the following types of injuries: C0 fractures, occipital condyle fractures (OCF), atlanto-occipital dislocation (AOD), atlas fractures, atlantoaxial dislocation (AAD), and axis fractures. Important aspects of the mechanisms of injury, clinical signs and symptoms, diagnostic procedures, and treatment options are discussed. Special emphasis is placed on comparatively reviewing the different treatment options discussed in the literature. A summary in table form is presented at the end of each chapter for quick reference.

Die rheumatisch bedingte Instabilität der oberen Halswirbelsäule

Rheumatic manifestation at the cervical spine occurs in more than 50% of all cases in the natural course of this disease. The first cervical manifestation takes place in the upper cervical spine. The initial involvement of the C1/C2 segment leads to atlantodental subluxation. Progressive destruction can result in vertical instability, which is characterized by cranial subluxation of the odontoid process with the danger of resulting stenosis and cervical myelopathy. The goal of diagnosis has to be the early recognition of these changes to establish an effective treatment protocol. Persistent pain, neurological deficits, and progressive radiological signs for instability are indications for operative stabilizing procedures. These procedures avoid progressive destruction and improve the prognosis regarding pain decrease, regression of neurological deficits, and life expectancy.

Fulminanter Myokardinfarkt bei einem ASA-I-Patienten nach Knieoperation in Allgemeinanästhesie

Myocardial ischemia is a major complication in the perioperative period, mostly in patients with high cardiac risks. After non-cardiac surgery myocardial infarction was observed in 5.6% of patients with coronary heart disease, the rate in patients with no cardiac diseases was 0.1-0.7%. We present the case of a 21-year-old ASA I male patient who underwent surgery to reconstruct the cruciate ligament of the knee. General anaesthesia was performed in combination with a femoral nerve block. After surgery the patient suffered from myocardial infarctions on the day of surgery and the 6th day after surgery. After resuscitation, thrombolysis and percutaneous transluminal coronary angioplasty (PTCA), an intraaortic balloon pump had to be temporarily implanted due to persistent cardiogenic shock.

[Rare pathological alterations of the upper cervical spine requiring surgical treatment]

Because of its unique anatomy, specific diseases and lesions arise in the upper cervical spine, which differ widely from the rest of the spine. During the last two decades standardised diagnostic and therapeutic algorithms have been defined for most of the craniocervical pathologies often occurring in combination with an underlying disease requiring surgical intervention as well. On the other hand there are some very rare phathological alterations: about 20% of the patients suffering from neurofibromatosis type I develop spinal deformities. These are mostly found in the thoracic and lumbar spine (dystrophic/non-dystrophic type). In rare cases the dystrophic neurofibromatosis type I involves the upper cervical spine leading to bizarre deformities endangering the spinal cord. An aggressive, timely and combined operative therapy is necessary. Patients with Down syndrome should be investigated regularly for affections of the upper cervical spine. Though only in about 1% of all patients with Down syndrome do instabilities require surgical intervention, the upper cervical spine should be screened on a regular basis, since neurological changes due to the pathognomy of the underlying disease often remain undetected for a long time. The operative therapy of the instable os odontoideum in Down syndrome follows the general principles of this pathoanatomical variation. Even though the Klippel-Feil syndrome is generally not linked with neuropathological findings, rare associated deformities of the upper cervical spine should be excluded by proper diagnostic procedures.

Ultrasonically implanted PLA suture anchors are stable in osteopenic bone

We compared the in vitro pullout strengths of a metallic screw-type suture anchor (5-mm Corkscrew) and a new ultrasonically implanted absorbable pin from cadaveric humeral heads with different bone densities. They were assessed quantitatively using microcomputed tomography. Pullout tests were done at four standardized sites and then correlated with the local bone density. The mean pullout strengths for the 5-mm Corkscrew and the 3.5-mm polylactic pin were similar in weak bone (76 +/- 24 N versus 104 +/- 46 N), intermediate quality bone (194 +/- 81 N versus 218 +/- 76 N), and strong bone (349 +/- 127 N versus 325 +/- 100 N). Pullout strength correlated with bone density for both implants (r = 0.76 and r = 0.86 for the Corkscrew and polylactic pin, respectively). The ultrasonically implanted absorbable 3.5-mm polylactic pin achieved equal pullout strength in weak bone as the larger 5-mm titanium Corkscrew. Bone density is highly variable in humeral heads and influenced the pullout strength of both implants.

Hygienic relevance and risk assessment of antimicrobial-impregnated textiles

The antimicrobial impregnation of textiles is intended to provide protection of textiles against microbial corrosion, prevention of malodor or prophylaxis and therapy of infections, respectively. For every biocidal product a careful risk assessment for humans and the environment has to be performed. The advantage of antimicrobially active textiles has to be documented for every agent as well as for every application, and a balance has to be found between a textile's quality rating and the potential risks, e.g. sensitization, disturbance of the ecology of the skin, toxic side effects by means of systemic absorption, cytotoxicity, genotoxicity, carcinogenicity, teratogenicity and ecotoxicity. This article evaluates the applicability of silver compounds as well as the classic antimicrobials triclosan, quaternary ammonium compounds, copper and further new options like chitosan and zeolite. It has to be emphasized that there are no objections against the use of antimicrobially active textiles if their use is equal or superior to other preventive or therapeutic measures. This applies to the amelioration of the course of dermatological diseases with disturbed skin flora, in particular atopic dermatitis, the prevention and therapy of acute and chronic wound infections by wound dressings, the use of impregnated surgical suture material as well as special indications in the prevention of infection in medical facilities. The use of antimicrobial textiles for the prevention of dermatomycosis by antifungal impregnation is of questionable use; the antimicrobial impregnation of textiles for deodorization purposes has to be avoided. Presently, from a hygienic point of view, the following questions have to be clearly determined: declaration of any antimicrobial impregnation; development of international standards for in vitro testing and preclinical evaluation of efficacy and tolerance; evaluation of the advantage of the antimicrobial properties for the intended use including the risk-benefit assessment.

Linear optics controlled-phase gate made simple

Linear optics quantum logic gates are the best tool to generate multiphoton entanglement. Simplifying a recent approach, we were able to implement the conditional phase gate with only one second-order interference at a polarization dependent beam splitter, thereby significantly increasing its stability. The improved quality of the gate is evaluated by analyzing its entangling capability and by performing full process tomography. The achieved results ensure that this device is well suited for implementation in various multiphoton quantum information protocols.

Experimental analysis of a four-qubit photon cluster state

Linear-optics quantum logic operations enabled the observation of a four-photon cluster state. We prove genuine four-partite entanglement and study its persistency, demonstrating remarkable differences from the usual Greenberger-Horne-Zeilinger (GHZ) state. Efficient analysis tools are introduced in the experiment, which will be of great importance in further studies on multiparticle entangled states.

Ankylosing spondylitis and heart abnormalities: do cardiac conduction disorders, valve regurgitation and diastolic dysfunction occur more often in male patients with diagnosed ankylosing spondylitis for over 15 years than in the normal population?

The objective of this study was to determine the rate of selected cardiac pathologies (conduction disorders, valve regurgitation and diastolic dysfunction) in patients with long-standing ankylosing spondylitis (AS) and compare the results with the prevalence in the normal population. A rheumatologic (structured questionnaire interview) and cardiac evaluation (resting electrocardiography and echocardiography) was performed in 100 male subjects with AS and a disease duration of more than 15 years. The rates for conduction disorders, aortic and mitral valve regurgitation and diastolic dysfunction were compared with the corresponding results in the literature among the normal population. In patients with long-standing AS there was no increased rate for valve regurgitation (mitral and aortic valve) and for arrhythmia. Diastolic dysfunction occurred more often in patients with long-standing AS. However, this might be caused by the presence of other cardiovascular risk factors such as age and hypertension. According to these results, a cardiologic evaluation with echocardiography should not be recommended routinely in patients with long-standing AS. To confirm these results, a large prospective study with patients with long-standing AS and with a matched control group should be performed in the future.

[Effect of vertebral body stiffness before and after vertebroplasty on intradiscal pressure]

Fractures of osteoporotic vertebral bodies are increasingly stabilized with bone cement. The effects of vertebral-body stiffness before and after augmentation with bone cement and of wedge-shaped vertebral body fractures on intradiscal pressure are insufficiently known. In a finite element model of the lumbar spine the elastic modulus of cancellous bone as well as the amount and the elastic modulus of bone cement were varied and the dependency of intradiscal pressure on these parameters was calculated. In addition, a wedge-shaped vertebral-body fracture was simulated. The bulge of the vertebral-body endplate and thus the intradiscal pressure depends strongly on the grade of osteoporosis in the vertebral body. The influence of amount and elastic modulus of bone cement on intradiscal pressure is small. A wedge-shaped vertebral-body fracture causes an anterior shift of upper-body centre of gravity. If this shift is not compensated, it leads to an increased flexion moment that has to be balanced by muscle forces. In addition, this shift leads to a stronger increase of intradiscal pressure than the augmentation of the vertebral body with bone cement.