Simulation of personalised haemodynamics by various mounting positions of a prosthetic valve using computational fluid dynamics.

Diseases of the cardiovascular system account for nearly 42% of all deaths in the European Union. In Germany, approximately 12,000 patients receive surgical replacement of the aortic valve due to heart valve disease alone each year. A three-dimensional (3D) numerical model based on patient-specific anatomy derived from four-dimensional (4D) magnetic resonance imaging (MRI) data was developed to investigate preoperatively the flow-induced impact of mounting positions of aortic prosthetic valves to select the best orientation for individual patients. Systematic steady-state analysis of blood flow for different rotational mounting positions of the valve is only possible using a virtual patient model. A maximum velocity of 1 m/s was used as an inlet boundary condition, because the opening angle of the valve is at its largest at this velocity. For a comparative serial examination, it is important to define the standardised general requirements to avoid impacts other than the rotated implantation of the prosthetic aortic valve. In this study, a uniform velocity profile at the inlet for the inflow of the aortic valve and the real aortic anatomy were chosen for all simulations. An iterative process, with the weighted parameters flow resistance (1), shear stress (2) and velocity (3), was necessary to determine the best rotated orientation. Blood flow was optimal at a 45° rotation from the standard implantation orientation, which will offer a supply to the coronary arteries.

Comparison of muscle and joint pressure-pain thresholds in patients with complex regional pain syndrome and upper limb pain of other origin.

Pain localized in the deep tissues occurs frequently in complex regional pain syndrome (CRPS). In addition, hyperalgesia to blunt pressure over muscles is common in CRPS, but it often appears in limb pain of other origin as well. Considering that 3-phase bone scintigraphy (TPBS) reveals periarticular enhanced bone metabolism in CRPS, joint-associated hyperalgesia to blunt pressure might be a more specific finding than hyperalgesia over muscles. In 34 patients with upper limb pain (18 CRPS, 16 non-CRPS; diagnosed in accordance to the Budapest criteria) and in 18 healthy controls, pressure-pain thresholds (PPT) were assessed bilaterally over the thenar (PPTThenar), the metacarpophalangeal (PPTMCP), and the proximal interphalangeal (PPTPIP) joints using a pressure algometer (Somedic, Sweden). Beforehand, all patients had received TPBS for diagnostic purposes independently of the study. Region-of-interest (ROI) ratios (mineralization phase) for the MCP and PIP, excluding fracture sites, were correlated with the PPT. In CRPS, all ROI ratios were significantly increased and all PPT of the affected hand were decreased compared to non-CRPS (PPTThenar: 243±150kPa vs 358±197kPa, PPTMCP: 80±67kPa vs 159±93kPa, PPTPIP: 80±56kPa vs 184±110kPa; P<.01) and controls (PPTThenar: 478±106kPa, PPTMCP: 254±50kPa, PPTPIP: 275±76kPa; P<.01). A PPTThenar below 293kPa revealed 77% sensitivity but only 63% specificity, whereas a PPTPIP below 102kPa had 82% sensitivity and 94% specificity to identify CRPS. Only in CRPS were PPTMCP and PPTPIP correlated significantly inversely with the ROI ratio (MCP: r=-0.439, PIP: r=-0.447). PPTPIP shows higher specificity for CRPS type I than PPTThenar without loss of sensitivity. Therefore, measurement of joint PPT could be a noninvasive diagnostic tool reflecting increased bone metabolism assessed by TPBS as a sign of bone pathophysiology.

Permanent lesion of the lateral femoral cutaneous nerve after low-volume ethanol 96%application on the lumbar sympathetic chain.

Lumbar sympathetic blocks and chemical sympathectomies are used for the pain treatment of peripheral arterial occlusive disease or sympathetically maintained pain syndrome after nerve injury or complex regional pain syndrome (CRPS). A 30-year-old patient was referred to the pain department with all the clinical signs and symptoms of a CRPS of the right foot one and a half years after being surgically treated for rupture of the achilles tendon. An inpatient admission was necessary due to insufficient pain reduction upon the current treatment, strong allodynia in the medial distal right lower leg and decreased load-bearing capacity of the right foot. A computed tomography (CT)-guided lumbar sympathetic block at the right L3 (Bupivacaine 0.5%, 4 mL) led to a skin temperature increase from 21° C before block to > 34° C for about 5 hours after the intervention. The patient experienced significant pain relief, indicating sympathetically maintained pain. Thus, we performed a CT-guided lumbar sympathetic neurolysis at the same level (ethanol 96%, 2 mL) 5 days later, achieving again a significant skin temperature increase of the right foot and a slight reduction of his pain intensity from numeric rating scale (NRS) 7 prior to the intervention to NRS 4 after 8 hours (NRS, 0 = no pain, 10 = strongest pain imaginable). Eight months later a repeated inpatient admission was necessary due to considerable pain relapse and decreased load-bearing capacity of his right foot. A CT-guided lumbar sympathetic neurolysis was repeated at the L4 level on the right side and was successful, inducing a significant skin temperature increase. Despite a temporary irritation of the genitofemoral nerve 8 hours after the intervention, a delayed irritation of the lateral femoral cutaneous nerve occurred. This was a long-lasting lesion of the lateral femoral cutaneous nerve following a CT-guided chemical sympathectomy with a low-volume ethanol 96% application - a complication which has not been described in literature until now. This is probably caused by broad dissemination of the neurolytic agent along the psoas muscle despite a correct needle position and spread of contrast agent. The development of this nerve injury even after injection of a small volume of ethanol (2 mL) may be delayed.

Different underlying pain mechanisms despite identical pain characteristics: a case report of a patient with spinal cord injury.

Pain following spinal cord injury has been classified as nociceptive (musculoskeletal, visceral) or neuropathic (above, at, below level). There is no clear relation between the etiology and reported symptoms. Thus, due to different underlying mechanisms, the treatment is often ineffective. We report on a patient with spinal cord injury with neurological level of injury at T8 suffering from bilateral burning and prickling pain in the T9-11 dermatomes bilaterally (at-level pain), as well as diffusely in both legs from below the torso (below-level pain), accompanied by musculoskeletal low back pain. Bilateral comparison of quantitative sensory testing (QST) and skin biopsy revealed completely different findings in the dermatome T9 despite identical at-level pain characteristics. On the right side, QST revealed a normal sensory profile; the intraepidermal nerve fiber density (IENFD) was reduced, but not as severe as the contralateral side. On the left side there was a severe sensory loss with a stronger reduction of the IENDF, similar to the areas below the neurological level. These findings were significantly related to the treatment results. Pregabalin induced unilateral pain relief only in the area with remaining sensory function, whereas the left-sided at-level pain was unchanged. Thus, 2 different underlying mechanisms leading to bilaterally neuropathic pain with identical symptoms and with different treatment success were demonstrated in a single patient. The at-level pain in areas with remaining sensory function despite IENFD reduction could be relieved by pregabalin. Thus, in an individual case, QST may be helpful to better understand pain-generating mechanisms and to initiate successful treatment.

Intra-individual, randomised comparison of the MRI contrast agents gadobutrol and gadoterate in imaging the distal lower limb of patients with known or suspected osteomyelitis, evaluated in an off-site blinded read.

OBJECTIVE: To prove that 1.0 M gadobutrol provides superior contrast enhancement in suspicion of osteomyelitis of the feet compared with 0.5 M gadoterate. METHODS: MRI of feet was performed on 2 separate occasions. Independent injections of 1.0 M gadobutrol and 0.5 M gadoterate at doses of 0.1 mmol Gd/kg body weight were administered per patient. The interval between the two MR examinations was between 24 h and 7 days. Evaluation was performed in an off-site blinded read. RESULTS: 41 patients were eligible for efficacy analysis. Results of secondary efficacy variables did not show statistically significant differences. For the primary efficacy variable, a trend in favour of gadobutrol was seen in the full analysis set (ITT) population resulting in at least non-inferiority. In the per protocol (PP) analysis set gadobutrol had better contrast than gadoterate (Wilcoxon signed rank test, p = 0.0466). CONCLUSION: Imaging of the distal lower limb in this special patient population requires a large number of patients to obtain enough comparative images where non-contrast-agent-dependent factors do not disturb contrast agent efficacy. The ITT analysis showed at least non-inferiority of gadobutrol in comparison to gadoterate. The avoidance of imaging artefacts demonstrates a better outcome for gadobutrol.

Sensitivity and specificity of 3-phase bone scintigraphy in the diagnosis of complex regional pain syndrome of the upper extremity.

OBJECTIVES: Joint and bone alterations are seldom mentioned in the diagnostic criteria for complex regional pain syndrome (CRPS) even though they are important for long-term outcome. Altered periarticular bone metabolism can be detected by 3-phase bone scintigraphy (TPBS). Although frequently examining the diagnostic efficacy of TPBS is debatable. METHODS: In all, 78 TPBS (45 CRPS/33 control group) were evaluated qualitatively and quantitatively. Sensitivity and specificity of the qualitative blinded reviewer analysis (n=57) compared with quantitative region of interest (ROI)-based analysis over the metacarpophalangeal, proximal, and distal interphalangeal joints (n=74) were evaluated. Patients' sex, age, duration of CRPS, inciting event, extent of joint alteration, and handedness were included as covariables. RESULTS: Qualitative blinded reviewer TPBS analysis had a high specificity (83%-100%). However, sensitivity was 31% to 50%. Interrater reliability was moderate (kappa score 0.56). Using the ROI-based evaluation, the highest sensitivity (69%) and specificity (75%) (ROI score > or =1.32) was shown for phase 3, whereas sensitivity of phases 1 and 2 rapidly declined to 50%. Duration of CRPS until TPBS was the only variable with significant impact on ROI scores of phase 3 (F=23.7; P=0.000; R=0.42). ROI scores declined with increasing duration of CRPS. DISCUSSION: In conclusion, TPBS is a highly specific tool for diagnosing CRPS of the upper limb. ROI evaluation of phase 3 within the first 5 months after onset of CRPS is an appropriate additional diagnostic tool to confirm or exclude CRPS of the upper extremity.

Sternal osteomyelitis: long-term results after pectoralis muscle flap reconstruction.

BACKGROUND: Reports regarding long-term follow-up including quality-of-life assessment, pulmonary function, and donor-site morbidity after operative treatment for sternal osteomyelitis are rare. METHODS: Data for 69 consecutive patients were acquired from patients' charts and contact with patients and general practitioners, with special reference to treatment and clinical course. Twenty-four patients were interviewed and physically examined (mean follow-up, 4 years; range, 1 to 9 years). Fifteen of the patients underwent pulmonary function tests, cine magnetic resonance imaging, and pectoralis strength testing using a dynamometer to record butterfly arm compressive movements. Statistical analysis was performed to identify factors influencing wound healing and survival. RESULTS: Mortality rates were 10.1 percent at 30 days, 18.5 percent at 1 year, and 27.0 percent at 5 years (n = 69). In 36.2 percent of the patients, wound-healing difficulties requiring reoperation occurred. Independent of the extent of sternal resection, dynamic pulmonary function values were decreased compared with normal values (n = 15). Dynamometer assessment revealed decreases of 1.5 percent in dynamic maximum strength, 9.7 percent in maximum isometric strength, and 47.2 percent in strength endurance compared with the healthy age-matched control group. Magnetic resonance imaging showed no sign of recurrent osteomyelitis (n = 15). Muscle function was preserved in 93 percent of the patients. Eighty-three percent of the interviewed patients considered their general condition better and 17 percent considered it worse than before the treatment (n = 24). CONCLUSIONS: Pectoralis muscle transfer represents a safe and simple procedure. Although strength loss and pain are considerable, quality of life is improved significantly. Pulmonary function impairment is most likely not exclusively attributable to the muscle transfer or the sternum resection.

[Radiological differential diagnosis of chronic back pain]. / Chronischer Rückenschmerz--Radiologische Differenzialdiagnostik bei degenerativen Veränderungen der Wirbelsäule.

Back pain is a frequent phenomenon. Published guidelines should be used to avoid unnecessary diagnostic imaging ("European guidelines for the management of chronic non-specific low back pain" - www.backpaineurope.org). Frequent degenerative changes and their correlation to acute and chronic back pain are described in the following text. Inflammation and tumour caused spine disease need special attention. A false choice of imaging procedure could delay the correct diagnosis.

Elastofibroma dorsi--differential diagnosis in chest wall tumours.

BACKGROUND: Elastofibromas are benign soft tissue tumours mostly of the infrascapular region between the thoracic wall, the serratus anterior and the latissimus dorsi muscle with a prevalence of up to 24% in the elderly. The pathogenesis of the lesion is still unclear, but repetitive microtrauma by friction between the scapula and the thoracic wall may cause the reactive hyperproliferation of fibroelastic tissue. METHODS: We present a series of seven cases with elastofibroma dorsi with reference to clinical findings, further clinical course and functional results after resection, as well as recurrence. Data were obtained retrospectively by clinical examination, phone calls to the patients' general practitioners and charts review. Follow-up time ranged from four months to nine years and averaged 53 months. RESULTS: The patients presented with swelling of the infrascapular region or snapping scapula. In three cases, the lesion was painful. The ratio men/women was 2/5 with a mean age of 64 years. The tumor sizes ranged from 3 to 13 cm. The typical macroscopic aspect was characterized as poorly defined fibroelastic soft tissue lesion with a white and yellow cut surface caused by intermingled remnants of fatty tissue. Microscopically, the lesions consisted of broad collagenous strands and densely packed enlarged and fragmented elastic fibres with mostly round shapes. In all patients but one, postoperative seroma (which had to be punctuated) occurred after resection; however, at follow-up time, no patient reported any decrease of function or sensation at the shoulder or the arm of the operated side. None of the patients experienced a relapse. CONCLUSION: In differential diagnosis of soft tissue tumors located at this specific site, elastofibroma should be considered as likely diagnosis. Due to its benign behaviour, the tumor should be resected only in symptomatic patients.

MRI Findings Do not Correlate with Outcome in Athletes with Chronic Groin Pain.

This trial aimed to assess the value of MRI in the differential diagnosis of chronic groin pain in athletes, a condition caused by various pathologies, the most common being posterior abdominal wall deficiency, osteitis pubis and muscular imbalance. Nineteen subjects with clinically ruled-out hernia and recurrent episodes of exercise-triggered groin pain were assessed. Dynamic MRI was performed under Valsalva manoeuver and at rest within a training- free period and after training activity. Follow-up was performed after 4 years using a questionnaire and physical examination. An incipient hernia was seen in one case, Valsalva manoeuver provoked a visible bulging in 7 others (3 bilateral). Eight athletes showed symphysitis (accompanied by bulging in 3 cases). MRI visualized one hydrocele, one osteoma of the left femur, one enchondroma of the pubic bone, and one dilated left ureter without clinical symptoms or therapeutic relevance. MRI findings after training and during the training free period did not vary. Fifteen participants were available for a follow-up control examination 4 years later - one suffered from ongoing pain, eleven were free of symptoms and three had improvement. However, most of them improved only with changing or reducing training. There were four participants with a specific therapy of their MRI findings. MRI revealed a variety of pathological findings in athletes suffering from chronic groin pain, but it was not reliable enough in differentiating between diagnoses requiring conservative or operative treatment. The MRI examination within the training interval did not have an advantage to that within the training-free period. Further randomized prospective trials with a long follow-up should establish whether MRI findings could be of help in the choice between conservative and surgical treatment for chronic groin pain. Key pointsMRI findings after training and during the train free period did not vary.MRI revealed a variety of pathological findings in athletes suffering from chronic groin pain, but it was not reliable enough in differentiating between diagnoses requiring conservative or operative treatment.