The capsular head of the proximal rectus femoris muscle: a review of the imaging anatomy of proximal muscle injury in professional athletes - early experience.

The detailed anatomy of the rectus femoris and corresponding injury appearances were first described in 1995. Since then, there has been little published to change our understanding of this complex anatomical area. More recent anatomical dissection work in 2004 and 2006 alluded to the presence of an altered configuration of the proximal tendon anatomy. Whilst widely accepted that the proximal rectus femoris muscle has two distinct tendon slips, the authors in 2006 described a third separate tendon slip arising from the anterior femoral capsule and this has been widely termed the 'capsular head'. We provide evidence that imaging features corroborate this revised anatomical concept. Whilst the clinical relevance of these findings is yet to be established, it remains important that our understanding of the radiological anatomy in this area advances with the forward growth of imaging clarity. In this review, we revisit anatomical concepts and present atypical injury cases that may be explained by the presence of a separate capsular head.

The Achilles Tendon: Imaging Diagnoses and Image-Guided Interventions-AJR Expert Panel Narrative Review.

The Achilles tendon is commonly affected by both chronic repetitive overuse and traumatic injuries. Achilles tendon injuries can potentially affect any individual but have a particularly high incidence in professional athletes. Appropriate imaging evaluation and diagnosis are paramount to guiding appropriate management. In this AJR Expert Panel Narrative Review, we discuss the role of various imaging modalities (particularly ultrasound and MRI) in the assessment of Achilles tendon pathology, focusing on the modalities' relative advantages and technical considerations. We describe the most common diagnoses affecting the Achilles tendon and adjacent structures, highlighting key imaging findings and providing representative examples. Various image-guided interventions that may be used in the management of Achilles tendon pathology are also reviewed, including high-volume injection, tendon fenestration, prolotherapy, and corticosteroid injection. The limited evidence supporting such interventions are summarized, noting an overall paucity of large-scale studies showing benefit. Finally, a series of consensus statements by the panel on imaging and image-guided intervention for Achilles tendon pathology are provided.

Os intermetatarseum: An analysis of morphology and case reports of fracture.

INTRODUCTION: The os intermetatarseum is an uncommon accessory ossicle of the foot located dorsally, between the bases of the first and second metatarsals that are usually asymptomatic. In the setting of trauma, this ossicle can clinically mimic a Lisfranc fracture-dislocation, a potentially disabling condition often requiring surgical intervention. METHODS: In this study, 47 cases of os intermetatarseum were reviewed across several Western Australian (WA) Hospitals and characterised based on morphology. Any fractures were recorded, and their cases were reviewed. RESULTS: The most common type of os intermetatarseum was freestanding at 63%, followed by the articulating type at 30%. Only 7% were of the fused type. Two acute fractures were identified on plain radiography and computed tomography (CT). CONCLUSION: The distribution of os intermetatarseum subtypes in the WA population is consistent with previous radiological studies. The two cases of isolated acute os intermetatarseum fracture are described, the first to our knowledge, highlighting the need for increased awareness of this ossicle in the setting of foot trauma.

Sonoelastography of Musculoskeletal Soft Tissue Masses: A Pilot Study of Quantitative Evaluation.

OBJECTIVES: To evaluate quantitative sonoelastography of benign and malignant musculoskeletal soft tissue masses. METHODS: We conducted a prospective study of 50 patients from a specialist sarcoma center who had extremity soft tissue masses referred for biopsy. After consent, the quantitative shear wave velocity (meters per second) was measured in longitudinal and transverse planes (3 readings in each plane and mean calculated). All masses subsequently underwent biopsy, excision, or both, with the histologic diagnosis taken as the reference standard. At a subsequent sitting, all anonymized B-mode sonograms were scored independently by 2 radiologists as benign or malignant with agreement by consensus if necessary. RESULTS: Of the 50 masses, 15 were malignant and 35 benign. Nine masses had incomplete velocity readings. Intraclass correlation coefficients for intra-reader reliability of velocity measurements were highly repeatable. There was preliminary evidence that the longitudinal shear wave velocity of malignant masses was on average 30% slower than that of benign masses (P< .10). Longitudinal and transverse shear wave measurements were moderately associated with each other (P = .003). There was no evidence that shear wave velocity varied with patient age, sex, or mass volume. For B-mode assessment of malignancy, sensitivity (Wilson 90% confidence interval) was 73.3% (52.1%, 87.4%), and specificity was 77.1% (63.8%, 86.6%). Interobserver agreement was substantial (κ= 0.86). Four of 15 malignant masses (26.6%) were incorrectly classified as benign on B-mode assessment (all grade 1 liposarcomas). CONCLUSIONS: These data suggest that shear wave velocity measurement is reproducible and that malignant masses may have slower longitudinal shear wave velocities than benign masses. The sample size of this pilot study precludes adjusted analysis but should form the basis for larger study designs.