Fasciae of the musculoskeletal system: MRI findings in trauma, infection and neoplastic diseases

Severe skin and soft tissue infection in cohort patients admitted in a teaching hospital in Belgium: identification of risk factors for surgery

BACKGROUND

Necrotizing soft tissue infections (NSTIs) are associated with significant mortality if not promptly diagnosed and surgically treated.

AIM

This study aims to compare patients with severe skin and soft tissue infection treated with or without a surgical intervention and to identify risk factors that can predict the need for early surgery.

METHODS

Demographics, clinical, laboratory, Risk Indicator for Necrotizing Fasciitis (LRINEC) and imaging results were retrospectively collected.

RESULTS

There were 91 non-NSTI (group 1), 26 NSTI who were operated (group 2) and eight suspected NSTI who were not operated (group 3). In the multivariate analysis, skin necrosis, tachycardia, CRP value and hyperglycemia were predictive for surgery. A performance analysis revealed AUC of 0.65 (95%CI: 0.52-0.78) as to the LRINEC score for the use of surgery. The AUC for a predictive model associating four variables (heart rate, skin necrosis, CRP and glycemia at admission) was 0.71 (95%CI: 0.59-0.84). In terms of outcome, the median length of stay (LOS) was statistically higher in group 2 vs. group 1 (seven days (5-15) vs. 34 days (20-42), p < .001) and in group 2 vs. group 3 (34 days (20-42) vs. 14 days (11-19), p = .005). The overall in-hospital mortality at 30 days was 3.2% and did not statistically differ between the three groups.

CONCLUSIONS

Although the LRINEC score performed well in predicting surgery, the AUC of a model combining four predictive variables (glycemia, skin necrosis, CRP and heart rate) was superior. Further research is needed to validate this model.

PET/CT and PET/MR in Soft Tissue Sarcoma: An Update

Soft tissue sarcomas account for 6%-8% of pediatric cancers. The rhabdomyosarcoma family is the most frequent soft tissue sarcoma in this age group accounting for 3% of pediatric cancers. Rhabdomyosarcomas are high-grade tumors with a high propensity to metastasize. The risk-adapted, multimodal therapeutic approach for rhabdomyosarcomas incorporates a combination of surgery, radiotherapy, and multi-agent cytotoxic chemotherapy. Soft tissue sarcomas other than rhabdomyosarcoma account for 3%-4% of pediatric cancers. The nonrhabdomyosarcoma soft tissue sarcomas include both low-grade and high-grade tumors. While surgery is the mainstay of therapy in most non-rhabdomyosarcoma soft tissue sarcomas, many cases require a multimodal therapeutic approach including radiotherapy and chemotherapy. In North America, most pediatric patients with soft tissue sarcomas are treated in Children's Oncology Group clinical trials. In this article, we will primarily focus on the staging, risk stratification, imaging recommendations, and interpretations in accordance with the Children's Oncology Group trials. We will review the results and recommendations of International Soft Tissue Sarcoma Database Consortium and European trials in relevant sections where they provide complementary guidelines.

Fasciitis ossificans: imaging features, histology, and differential diagnosis

AIM

To describe the imaging features of fasciitis ossificans and its histopathological features.

MATERIALS AND METHODS

Using a word search of existing pathology reports at the Mayo Clinic, six cases of fasciitis ossificans were identified. The clinical history, histology, and available imaging of the affected area were reviewed.

RESULTS

Imaging consisted of radiographs, mammograms, ultrasound images, bone scintigraphs, computed tomography (CT), and magnetic resonance imaging (MRI) images. All cases demonstrated a soft-tissue mass. The characteristic MRI appearance was a T2 hyperintense enhancing mass with surrounding soft-tissue oedema. Peripheral calcifications were seen on radiographs, CT, and/or ultrasound. Histological sections showed distinct zonation, with nodular fasciitis-like zones of myofibroblastic proliferation, which merged with osteoblasts that rim the ill-defined trabeculae of woven bone and became continuous with the mature lamellar bone surrounded by a thin layer of compressed fibrous tissue.

CONCLUSION

Imaging features of fasciitis ossificans are that of an enhancing soft-tissue mass located within a fascial plane with prominent surrounding oedema and mature peripheral calcification. Imaging and histology are that of myositis ossificans but occurring within the fascia. It is important that radiologists are aware of the diagnosis of fasciitis ossificans and appreciate its similarity to myositis ossificans. This is particularly important in anatomical locations with fascias but no muscle. Given the radiographic and histological overlap between these entities, nomenclature that encompasses both could be considered in the future.

Musculoskeletal Soft-tissue Masses

Evaluation of soft-tissue masses has become a common clinical practice indication for imaging with both ultrasound and MR imaging. We illustrate the ultrasonography and MR imaging appearances of soft-tissue masses based on the various categories, updates, and reclassifications of the 2020 World Health Organization classification.

Innervation of human superficial fascia

The superficial fascia has only recently been recognized as a specific anatomical structure. Furthermore, whereas it is actually recognized that the innervation of the deep/muscular fascia plays a key role in proprioception and nociception, there are very few studies that have analyzed these characteristics in the superficial fascia. In this work, our group analyzed two different anatomical districts (abdomen and thigh), from volunteer patients, undergoing surgery procedures. Each sample was processed for histological analysis by Hematoxylin&amp;Eosin, and by immunohistochemistry stainings (in 5-micron-paraffin embedded section and in cryosectioned free floating samples), with antibodies specific for nerve fibers: S100 antibody for myelinating and non-myelinating Schwann cells, PGP9.5 antibody as pan-neuronal marker, tyrosine hydroxylase for autonomic innervation. The results revealed a huge innervation: the nervous structures were found above all around blood vessels and close to adipocytes, but they penetrated also in the connective tissue itself and are found in the midst of fibro-adipose tissue. The tissue is pervaded by both thin (mean diameter of 4.8 ± 2.6 μm) and large nerve fiber bundles of greater diameter (21.1 ± 12.2 μm). The ratio S100/TH positivity was equal to 2.96, with a relative percentage of autonomic innervation with of 33.82%. In the light of these findings is evident that the superficial fasciae have a clear and distinct anatomical identity and a specific innervation, which should be considered to better understand their role in thermoregulation, exteroception and pain perception. The knowledge of the superficial fascia may improve grading and developing of different manual approach for treatments of fascial dysfunctions, and the understanding of how some factors like temperature or manual therapies can have an impact on sensitivity of the fascia.

Differential diagnosis of acute traumatic hip pain in the elderly

Elderly patients who present with an inability to weight bear following a fall, with normal radiographs, should be appropriately investigated to rule out an occult hip fracture (OHF). We aim to identify both the range and incidence of the differential diagnosis of acute traumatic hip pain in a large series of patients investigated for OHF. A retrospective analysis of consecutive patients investigated for an OHF with magnetic resonance imaging (MRI) was performed. Dedicated musculo- skeletal radiologists reported the MRI scans. All diagnoses including hip fractures, other fractures and soft tissue injuries were recorded. Case notes were reviewed for all patients to identify subsequent complications, management and outcomes. A total of 157 patients fulfilled the inclusion criteria. 52 (33%) patients had a fracture of the proximal femur. The majority of patients with proximal femoral fractures required surgical intervention. 9 patients who had fractures of the greater trochanter of the femur without fracture extension across the femoral neck were managed non-operatively. 40 (25%) patients had fractures of the pelvis, with a combined pubic rami and sacral fracture occurring frequently. The most common diagnosis was a soft tissue injury alone that was seen in 60 (38%) patients imaged. Injuries to the gluteal muscle group, iliopsaos complex and trochanteric bursa were most prevalent. All patients with soft tissue injuries or fractures of the pelvis were successfully managed non-operatively. This study highlights a wide range of differential diagnoses in elderly patients presenting with acute traumatic hip pain. The proximal femur was frac- tured in 33% of patients imaged for OHFs in our series. The most common diagnosis was a soft tissue injury around the hip and pelvis ; these injuries can be successfully managed without surgery.

MRI nomenclature for musculoskeletal infection

The Society of Skeletal Radiology (SSR) Practice Guidelines and Technical Standards Committee identified musculoskeletal infection as a White Paper topic, and selected a Committee, tasked with developing a consensus on nomenclature for MRI of musculoskeletal infection outside the spine. The objective of the White Paper was to critically assess the literature and propose standardized terminology for imaging findings of infection on MRI, in order to improve both communication with clinical colleagues and patient care.A definition was proposed for each term; debate followed, and the committee reached consensus. Potential controversies were raised, with formulated recommendations. The committee arrived at consensus definitions for cellulitis, soft tissue abscess, and necrotizing infection, while discouraging the nonspecific term phlegmon. For bone infection, the term osteitis is not useful; the panel recommends using terms that describe the likelihood of osteomyelitis in cases where definitive signal changes are lacking. The work was presented virtually to SSR members, who had the opportunity for review and modification prior to submission for publication.

Multimodality imaging features of desmoid tumors: a head-to-toe spectrum

Desmoid tumors (DTs) are a rare and biologically heterogeneous group of locally aggressive fibroblastic neoplasm: their biological behavior spectrum ranges from indolent to aggressive tumors. DTs are classified as intra-abdominal, extra-abdominal, and within the abdominal wall lesions.It is well known that abdominal and extra-abdominal DTs are associated with familial adenomatous polyposis (FAP) and Gardner syndrome. Possible risk factors are prior trauma/surgery, pregnancy, and oral contraceptives.There was a real revolution in the management of DT: from aggressive first-line approach (surgery and radiation therapy) to a more conservative one (systemic treatment and "wait-and-see policy").In these clinical settings, radiologists play an important role for assessing lesion resectability, evaluating recurrence, monitoring the biological behavior if an expectant management is chosen, and assessing response to systemic treatment as well as to radiation therapy.Awareness of common locations, risk factors, and imaging features is fundamental for a correct diagnosis and an adequate patient management.

Is experience alone sufficient to diagnose developmental dysplasia of the hip without the bony roof (alpha angle) and the cartilage roof (beta angle) measurements?: A diagnostic accuracy study

In the Graf method of hip ultrasonography, the diagnosis of the infantile hip with developmental dysplasia of the hip (DDH) is strictly dependent on the bony roof (alpha angle) and the cartilage roof (beta angle) measurements. In this study, we investigated whether the infant hip could be diagnosed with DDH solely by evaluating ultrasound images obtained in the standard plane, without bony roof and cartilage roof measurements, in respect to different professional experience levels.Two hundred ten hip ultrasounds were randomly selected from patients who presented to our hospital for DDH screening. A total of 6 ultrasound images were obtained for each hip. The hip morphology evaluations were made without the bony roof and the cartilage roof measurements by 2 orthopedic surgery residents; 2 orthopedic surgery specialists, trained in the diagnosis and the treatment of the DDH; and 2 pediatric orthopedic surgery professors, highly experienced in the diagnosis and treatment of DDH. After hip morphology evaluations, the bony roof and the cartilage roof measurements were obtained and hip type evaluations were made by the same raters, according to the Graf method of hip ultrasonography.The highest intraobserver agreements between the hip maturity evaluation before and the hip type evaluation after measurements were .676 (P < .001) and .577 (P < .001) in professors 2 and 1, respectively, and the lowest agreements were .185 (P < .01) and .289 (P < .001) in specialist 1 and resident 2, respectively.The diagnosis of the infant hip as DDH could not be made solely by evaluation of the ultrasound images obtained in the standard plane without the bony roof and the cartilage roof measurements. The bony roof and the cartilage roof measurements were obligatory for the diagnosis of the infant hip as DDH, even in the very experienced pediatric orthopedic surgeons.Level of evidence: 2.