[Intraosseous foreign body or osteoma : Challenging differential diagnosis after open radius fracture]. / Intraossärer Fremdkörper oder Osteom : Anspruchsvolle Differenzialdiagnose nach offener Radiusfraktur.

Presentation of a 16-year-old male patient due to a cycling accident while mountain biking 14 days after primary treatment after open epiphyseal injury. Metaphyseal intraosseous stones within the anatomically reduced distal radius fracture were misinterpreted as an incidental osteoma.

[Differential diagnoses of osteonecrosis of large joints]. / Differenzialdiagnosen der Osteonekrose großer Gelenke.

Subchondral insufficiency fractures and idiopathic bone marrow edema syndrome are the most important differential diagnoses to be distinguished from osteonecrosis because they have a deviating and as a rule more favorable prognosis and also different therapeutic strategies. Osteochondritis dissecans represents a different entity in many respects, which should not be confused or unified with osteonecrosis. Based on recent knowledge intractable subchondral insufficiency fractures may be the underlying cause of rapidly destructive osteoarthritis at least in some cases. Septic involvement of bone and joints can eo ipso cause severe articular damage due to direct destruction but also secondary to septic vascular occlusion resulting in septic osteonecrosis. Whereas bone marrow infiltrating systemic diseases and the therapeutic regimens can lead to osteonecrosis, bone tumors or tumor-like diseases, rarely pose a differential diagnostic problem with respect to the differentiation from osteonecrosis.

[Differential diagnoses of osteonecrosis of large joints]. / Differenzialdiagnosen der Osteonekrose großer Gelenke.

Subchondral insufficiency fractures and idiopathic bone marrow edema syndrome are the most important differential diagnoses to be distinguished from osteonecrosis because they have a deviating and as a rule more favorable prognosis and also different therapeutic strategies. Osteochondritis dissecans represents a different entity in many respects, which should not be confused or unified with osteonecrosis. Based on recent knowledge intractable subchondral insufficiency fractures may be the underlying cause of rapidly destructive osteoarthritis at least in some cases. Septic involvement of bone and joints can eo ipso cause severe articular damage due to direct destruction but also secondary to septic vascular occlusion resulting in septic osteonecrosis. Whereas bone marrow infiltrating systemic diseases and the therapeutic regimens can lead to osteonecrosis, bone tumors or tumor-like diseases, rarely pose a differential diagnostic problem with respect to the differentiation from osteonecrosis.

[Atraumatic and aseptic osteonecrosis of large joints]. / Atraumatische und aseptische Osteonekrose großer Gelenke.

Subchondral osteonecrosis of large weight-bearing joints (hip and knee joints) represents a severe and joint-threatening disease. Apart from idiopathic forms, glucocorticoid medication and alcohol abuse have been identified as major causative factors for atraumatic osteonecrosis. In addition to direct cytotoxic factors, a critically reduced perfusion of the subchondral osseous space will eventually lead to bone marrow ischemia and osseous necrosis. Magnetic resonance imaging (MRI) is capable of visualizing a reactive border-like zone in this early, already irreversible and often asymptomatic stage I according to the Association of Research Circulation Osseous (ARCO) staging system. Later in the course, osteonecrosis progresses to form serpiginous sclerotic lines, enclosing the necrotic bone area (stage II ARCO). Repair mechanisms of osteonecrosis are mostly unsuccessful and depending on the size of the osteonecrosis result in biomechanical failure and ultimately subchondral insufficiency fractures (crescent sign), thus marking the transition to stage III ARCO (joint surface collapse).

[Foot and ankle tumours : Part II: Malignant bone tumours and soft tissue tumours of the foot with differential diagnostic hints]. / Tumoren des Fußes und der Sprunggelenkregion : Teil II: Maligne Knochentumoren und Weichteiltumoren des Fußes mit differenzialdiagnostischen Hinweisen.

CLINICAL ISSUE: Both benign and malignant tumours are encountered in the foot and ankle. Due to their rarity, however, diagnosis is often uncertain. Usual criteria such as tumour size, invasiveness or pain fail to differentiate benign from malignant neoplasias. STANDARD RADIOLOGICAL METHODS: Plain radiography and-due to the complex foot anatomy-CT are important in the diagnostic evaluation of primary bone tumours. In the case of soft tissue tumours, ultrasonography is used to identify ganglion cysts. Tumour evaluation and staging are then performed using MRI. Nuclear imaging comes into play when multifocal, metastatic or systemic spread of the disease is suspected or if a biopsy procedure is planned. METHODICAL INNOVATIONS: For the role of dual-energy CT, please refer to part I. Whether dual-energy CT is suitable to assess bone marrow oedema patterns is still debated. SPECIAL FEATURES OF FOOT AND ANKLE TUMOURS: Primary bone tumours generally present in the ankle or the hindfoot. Malignant bone tumours, e. g. chondrosarcoma, are primarily found in the latter. On the other hand, soft tissue tumours generally present in the mid- and forefoot regions. ACHIEVEMENTS: While the radiologic diagnostic evaluation of pedal bone tumours is quite reliable, caution is urgently needed in the case of soft tissue tumours because there are many confusing differential diagnoses. PRACTICAL RECOMMENDATIONS: Proper X­ray examination of the foot (at least in two plains) or with special views according to bony pathology is needed. All soft tissue masses that are not cysts should be evaluated further. MRI remains the diagnostic modality of choice but never stands alone! Caution: Size and well-defined margins of pedal soft tissue tumours are not considered criteria regarding whether a tumour is malignant or not.

[Foot and ankle tumours : Part I: overview of incidence, diagnosis and staging of pedal tumours]. / Tumoren des Fußes und der Sprunggelenkregion : Teil I: Überblick zu Häufigkeit, Diagnostik und Staging pedaler Tumore.

CLINICAL ISSUE: Foot and ankle tumours are rare. Part I of this paper provides a survey about tumour distribution regarding age and location of benign and malignant bone and soft tissue tumours. STANDARD RADIOLOGICAL METHODS: All diagnostic radiological procedures are used for the diagnostic work-up of pedal tumours, in particular plain radiography, MRI, and ultrasonography. METHODICAL INNOVATIONS: Dual-energy CT proves to be a valuable (differential) diagnostic tool in identifying urate dihydrate crystals. PERFORMANCE: There are no reliable numbers available on accuracy of the aforementioned diagnostic procedures regarding tumour detection and identification. This is particularly true for soft tissue tumours which are small and well-defined, thus requiring histological clarification. ACHIEVEMENTS: To evaluate pedal tumours correctly and reasonably, a full range of radiological diagnostics should be employed. Neither plain radiography alone nor a stand-alone MRI examination-depending on the tumour site-are sufficient to characterize such tumours including staging. PRACTICAL RECOMMENDATIONS: Plain radiography remains the first-choice imaging modality. Ultrasonography is superior to reliably detect and identify ganglion cysts. MRI, however, continues to remain the upmost diagnostic modality of choice for evaluating foot and ankle tumours. CT possesses unchallanged diagnostic power to assess osseous changes. Bone scintigraphy (including SPECT-CT) and FDG-PET imaging are used when multifocal distribution or metastatic disease are suspected or to detect avidity of the pedal lesions, respectively.

[Soft tissue sarcoma: how can posttreatment alterations be distinguished from recurrences?] / Weichteilsarkome: Wie lassen sich posttherapeutische Veränderungen von Rezidiven unterscheiden?

The recognition of recurrent soft tissue sarcomas and the differentiation from post-treatment alterations is complex. This article aims to assist the clinical radiologist in the systematic evaluation of local follow-up imaging in soft tissue sarcoma patients. Soft tissue sarcomas encompass multiple entities with different recurrence rates and follow-up intervals. Approved and up to date recommendations are provided, including imaging techniques. The past medical history of the patient, the clinical situation and previous therapies should be known in detail, including surgery, radiation therapy and chemotherapy. Previous imaging results should be consulted, if available. This article describes the time-dependent imaging spectrum of local post-therapeutic as well as local treatment-related complications. These include early complications, such as seromas, hematomas and infections, as well as late complications, including edema, fibrosis and joint stiffness, and also inflammatory pseudotumors, which may occur after variable time intervals. The imaging appearance of local recurrent and radiation-associated sarcoma are elucidated. In particular, magnetic resonance imaging (MRI) criteria are provided, which may help in differentiating post-therapeutic alterations from recurrent soft tissue sarcomas.

[Postoperative and posttherapeutic changes after primary bone tumors : What's important for radiologists?] / Postoperative und posttherapeutische Veränderungen nach primären Knochentumoren : Was ist wichtig für den Radiologen?

Posttreatment imaging of primary bone tumours represents a diagnostic challenge for radiologists. Depending on the primary bone tumour common radiological procedures, such as radiography, computed tomography (CT), and magnetic resonance imaging (MRI), are employed. Radiography and CT are particularly useful in benign bone tumours and in matrix-forming bone tumours. MRI comes into consideration with malignant tumour recurrence and tumoral soft tissue infiltration. Bone scintigraphy is of superior importance if a primarily multifocal manifestation of bone tumour or metastasizing tumour disease is suspected. Molecular imaging (FDG-PET and hybrid imaging, using CT) are gaining increasing importance in light of monitoring neoadjuvant chemotherapy and detecting recurrent tumour appearance. The current literature shows sensitivity and specificity values for recurrent detection of up to 92% and 93%. Diagnostic accuracy is as high as 95%, thus, exceeding accuracy values for CT (67%) and MRI (86%) by far. Likewise, this is also applicable for the assessment of the neoadjuvant chemotherapy. Moreover, PET-based modalities are able to establish prognostic statements using SUV-threshold values at baseline (especially for Ewing sarcomas). Advanced imaging techniques have made a great diagnostic step forward and have proven to be relevant and reproducible with respect to both relapse detection and treatment assessment. Furthermore, it is not clear whether a higher detection rate of early tumour recurrence will inevitably lead to better outcome and survival.

[Unusual complication following placement of an epidural catheter]. / Ungewöhnliche Komplikation nach Anlage eines Periduralkatheters.

We report an unusual complication following placement of a thoracic epidural catheter in a patient that had undergone surgery for pulmonary metastases of a malignant melanoma. The intra- and postoperative course was initially without complications. At 2 days, there was a small, conspicuous swelling above the site of epidural puncture, which was neither reddened nor painful. No neurological deficits were observed, and the patient explained that he had been aware of the swelling for more than 6 months; thus, the epidural catheter was not deemed to be responsible. After catheter removal on day 4, an apparently purulent fluid drained from the puncture site. Although the patient had not reported this in the initial medical examination, he now explained that this cutaneous process had been squeezed out by his wife several times before. We initially obtained an exudate by means of ultrasound-guided puncture, and two epidermal cysts were detected on subsequent magnetic resonance imaging (MRI). The epidural catheter had been placed through one of these epidermal cysts. After reassessing the medical files, we found the earlier reports of two positron emission tomographies in which two epidermoid cysts were described at the level of thoracic vertebra 5/6 and 6/7. Facklamia hominis was detected in the pure culture. To avoid bacterial infection, we treated the patient for 7 days with antibiotics. The clinical course was without further pathological findings.

Radiation dose reduction in scoliosis patients: low-dose full-spine radiography with digital flat panel detector and image stitching system.

PURPOSE: To evaluate the exposure dose reduction with a digital flat panel detector (FPD) and an image stitching system (ISS) in full-spine radiography for scoliosis patients. MATERIALS AND METHODS: During a 6-month period, all consecutive scoliosis patients with a clinical indication for full-spine radiography (n = 50) were examined with an FPD and ISS. Automatic exposure control adjusted to speed class 1600 was used together with age-adjusted tube voltage and filtration. Dose area products were recorded for all images (antero-posterior n = 50, lateral n = 18). Images were evaluated by two radiologists for the possibility (possible, impossible) of typical scoliosis measurements (Cobb angle, Stagnara angle, lateral deviation, Risser stage). All measurements assessed as impossible underwent a second evaluation categorizing the reason why a measurement was impossible (underlying pathology, projection, image quality). Patient characteristics influencing exposure were recorded (sex, age, weight, height). Mean dose area products were compared to the literature with consideration of patient group and image quality. RESULTS: The mean dose area product was 16.8 µGy m (2) for antero-posterior images and 26.6 µGy m (2) for lateral images. A comparison to published values showed an exposure dose reduction of 47 % to 93 %. Measurement of the Cobb and Stagnara angle, lateral deviation and Risser stage was possible in 96 % (n = 50), 83 % (n = 18), 100 % (n = 50) and 100 % (n = 50) of cases. The reasons for impossible measurements were independent of image quality (underlying pathologies, projection). CONCLUSION: When imaging scoliosis patients, an FPD combined with an ISS can substantially reduce the exposure dose.

The effect of polytrauma as a possible confounder in the outcome of monotraumatic vs polytraumatic paraplegic patients: a clinical cohort study.

STUDY DESIGN: Clinical cohort study. OBJECTIVE: To evaluate if the impact of the severity of the trauma as a possible confounding factor influences the neurological and functional recovery in paraplegia during the course of a 6-month follow-up period after injury. SETTING: Spinal Cord Injury Center, Heidelberg University Hospital, Germany. METHODS: A retrospective monocentric analysis, from 2002 to 2008, of the Heidelberg European Multicenter Study about spinal cord injury database was performed. We included 31 paraplegic patients (neurological level T1-T12) who were assigned either to a monotrauma (polytraumaschluessel (PTS) 1) or to a polytrauma (PTS≥2) group. The American Spinal Injury Association Impairment Scale, lower extremity motor score, pin prick, light touch and the spinal cord independence measure (SCIM) were obtained at five distinct time points after trauma. Data were analyzed using Mann-Whitney U-test (α<0.05). RESULTS: The changes in lower extremity motor score, pin prick and light touch showed no significant differences in both groups over the whole evaluation period. Polytraumatic paraplegics showed a significantly delayed increase of SCIM between 2 and 6 weeks compared with monotraumatic patients, followed by a quantitative increase in the subitems bladder management, bowel management, use of toilet and prevention of pressure sores between 3 and 6 months (P=0.031). The mean length of primary rehabilitation in the polytrauma group was 5.5 vs 3.6 months in monotrauma. CONCLUSIONS: The prognosis of polytraumatic paraplegics in terms of neurological recovery is not inferior to those with monotrauma. Multiple-injured patients need a prolonged hospital stay to reach the functional outcome of monotraumatic patients.

Progressive spastic paraplegia: the combination of Scheuermann's disease, a short-segmented kyphosis and dysplastic thoracic spinous processes.

STUDY DESIGN: Case report. OBJECTIVE: To describe a rare case of paraplegia in a patient with Scheuermann's disease and dysplastic thoracic spinous processes. SETTING: Spinal Cord Injury Center, Orthopaedic University Hospital Heidelberg, Heidelberg, Germany. CLINICAL PRESENTATION: The authors report on a 15-year-old boy with progressive incomplete spastic paraplegia presenting segmental dysplastic thoracic spinous processes and Scheuermann's disease. The magnetic resonance imaging showed a kyphotic angulation at T 5/6 and signs of myelopathy. Hypoplastic thoracic processes and hypoplastic paraspinal muscles in the upper thoracic spine were observed intraoperatively. In this case, dorsoventral stabilization from T 4-7 was performed and the neurological outcome improved at follow-up (6 months). CONCLUSION: Paraplegia can be accelerated in patients with Scheuermann's disease, severe kyphotic angulation and dysplastic posterior elements. After operative treatment, neurological recovery and a normal walking pattern were shown.

[Significance of findings of chest X-rays and thoracic CT routinely performed at the emergency unit: 102 patients with multiple trauma. A prospective study]. / Relevanz der Befunde von Thoraxröntgen und Thorax-CT im routinemssigen Schockraumeinsatz bei 102 polytraumatisierten Patienten. Eine prospektive Studie.

PURPOSE: To evaluate prospectively whether and to what extent both thoracic computed tomography (Tx-CT) and supine X-ray of the chest (Rx-Tx) are able to show additional findings that are therapeutically relevant. PATIENTS AND METHODS: According to a fixed study protocol, we performed Rx-Tx and Tx-CT in 102 consecutive, haemodynamically stable polytrauma patients (mean age, 41.2 yrs; age range, 12-93 yrs). Findings of therapeutical relevance drawn from both Tx-CT and Rx-Tx, and urgent interventions indicated by an attending trauma team were documented on a standardized evaluation sheet immediately. Any change in the patient's management that is different from routine life-saving procedures, and any therapeutical intervention done in the emergency room or elsewhere (operating theatre, angiographic facility) were considered therapeutically relevant. RESULTS: Of 102 patients, 43 (42.2%) had a total of 51 therapeutically relevant findings. Rx-Tx alone yielded 23 relevant findings (45.1%) in 23 patients (22.5%). Of them, Tx-CT has shown additional important findings in 7 patients (30.4%). When Tx-CT alone is considered, it revealed 22 new findings of therapeutical relevance (43.2%) in 20 patients (46.5%). Altogether, Tx-CT was able to show 30 relevant findings in 27 patients, i.e., there was a therapeutical benefit for 26.5% of all polytrauma patients included. Most frequently, there was a need for chest-tube insertion (n = 29). CONCLUSIONS: Polytrauma patients if haemodynamically stable may profit from computed tomography of the chest when therapeutically relevant thoracic injuries are looked for or early therapeutical interventions are to be checked. However, chest X-ray should stay as a "front-line" screening method because of its superbly quick feasibility and availability.

Bronchogenic cyst. A rare differential diagnosis of retroperitoneal tumors.

Subdiaphragmatic bronchogenic cysts are rare, and those located retroperitoneally are exceptional. A review of the English-language literature revealed only 16 reported cases. We describe an additional case of a retroperitoneal cyst presenting as an asymptomatic adrenal mass and discuss clinical, radiographic, surgical and pathological findings as well as its embryological background.