Intraosseous lipomas originating from simple bone cysts.

PURPOSE: Fatty or part-fatty intraosseous lesions are occasionally encountered while imaging the skeletal system. A number of case reports have proposed involution of calcaneal bone cysts to intraosseous lipomas, but this has never been proven. This paper sets out to prove that simple bone cysts (SBCs) can involute to fatty lesions indistinguishable from intraosseous lipomas. MATERIALS AND METHODS: The pathology and PACS databases at 2 specialist orthopedic hospitals were retrospectively interrogated for all cases of intraosseous lipomas or SBCs with cross-sectional imaging follow-up for SBCs and precursor or follow-up imaging for intraosseous lipomas, in the time period from August 2007 to December 2016. For intraosseous lipoma cases, these were only included if change in imaging appearances was observed. RESULTS: There was no case of change in the appearance in intraosseous lipomas. Six cases of SBC with cross-sectional imaging follow-up were identified in one participating hospital and none in the other. The 6 cases were comprised of 4 male and 2 female patients. Two were located in the proximal humerus, one in the proximal tibia, and 3 in the os calcis. All cases demonstrated filling in of the cystic lesion with fat from the periphery, in 2 cases complete filling in, and in 4 cases partial fatty conversion. CONCLUSION: SBCs can heal with fatty conversion of the cystic cavity, with partly cystic remnants. It is proposed that at least part of the so-called intraosseous lipomas are healed simple bone cysts.

Acute Kidney Injury in Patients Undergoing Hip Fracture Surgery.

BACKGROUND: Hip fracture is common in elderly patients and is associated with high morbidity and mortality. Acute kidney injury (AKI) following hip fracture may have additional impact on clinical outcomes. OBJECTIVES: To investigate the incidence of AKI, the risk factors for its occurrence and impact on mortality, timing of surgery, and length of hospitalization (LOS) in patients undergoing hip fracture surgery. METHODS: We retrospectively examined the records of patients who underwent hip fracture surgery between 2013 and 2017. All patients had a baseline serum creatinine value and at least one later value. AKI was defined according to KDIGO guidelines. RESULTS: The study included 511 patients. Mean age was 72.6 years, 325 males (63.4%); 151 (29.5%) had baseline eGFR < 60 ml/min/1.73m2. Of these, 87 (17%) developed AKI. Older age, diabetes mellitus, hypertension, and chronic heart condition were significantly more common in patients who developed AKI. Patients with AKI had increased 30-day mortality (hazard ratio [HR] 3.96, 95% confidence interval [95%CI] 1.62-9.7, P = 0.003) and mortality at one year (HR 2.72, 95%CI 1.5-4.9, P = 0.002). AKI was associated with surgery delay > 48 hours (HR 2.241, 95%CI 1.206-4.165, P = 0.011). Mean LOS was 10.9 days and 8 days for patients with AKI and without, respectively, P < 0.0001. CONCLUSIONS: AKI is a common complication in patients with hip fracture and is associated with increased short- and long-term mortality, delayed surgery, and longer hospitalization. Interventions identifying and monitoring patients at risk may contribute to improve the outcomes.

MRI of the tibioastragalus anticus of Gruber muscle: a rare accessory muscle and normal anatomical variant.

We present the case of a 31-year-old man who sustained a hyperplantar flexion injury of his right ankle, and was evaluated using computed tomography and MRI to assess for osseous and ligamentous injury. The MRI and CT studies demonstrated a tibioastragalus anticus of Gruber (TAAG) muscle in the lower limb's anterior compartment. To our knowledge, the imaging of this muscle has not been previously described. The TAAG muscle arises from the lower third of the anterolateral tibia and the interosseous membrane. Its tendon passes laterally, deep to the tibialis anterior and extensor hallucis longus tendons, and inserts onto the anterior superolateral neck of the talus in a fan-like manner. Knowledge and recognition of this tendon are important for both diagnostic accuracy and surgical planning, and could potentially be used as a tendon transfer or graft in the appropriate clinical setting. The presence of this accessory muscle should not be confused with a pathological condition.

Role of US Contrast Agents in the Assessment of Indeterminate Solid and Cystic Lesions in Native and Transplant Kidneys.

Ultrasonography (US) is often the initial imaging modality employed in the evaluation of renal diseases. Despite improvements in B-mode and Doppler imaging, US still faces limitations in the assessment of focal renal masses and complex cysts as well as the microcirculation. The applications of contrast-enhanced US (CEUS) in the kidneys have dramatically increased to overcome these shortcomings with guidelines underlining their importance. This article describes microbubble contrast agents and their role in renal imaging. Microbubble contrast agents consist of a low solubility complex gas surrounded by a phospholipid shell. Microbubbles are extremely safe and well-tolerated pure intravascular agents that can be used in renal failure and obstruction, where computed tomographic (CT) and magnetic resonance (MR) imaging contrast agents may have deleterious effects. Their intravascular distribution allows for quantitative perfusion analysis of the microcirculation, diagnosis of vascular problems, and qualitative assessment of tumor vascularity and enhancement patterns. Low acoustic power real-time prolonged imaging can be performed without exposure to ionizing radiation and at lower cost than CT or MR imaging. CEUS can accurately distinguish pseudotumors from true tumors. CEUS has been shown to be more accurate than unenhanced US and rivals contrast material-enhanced CT in the diagnosis of malignancy in complex cystic renal lesions and can upstage the Bosniak category. CEUS can demonstrate specific enhancement patterns allowing the differentiation of benign and malignant solid tumors as well as focal inflammatory lesions. In conclusion, CEUS is useful in the characterization of indeterminate renal masses and cysts.

Transverse carpal ligament tear at the trapezial ridge without fracture - the "trapezial ridge line" sign: two case reports.

A tear of the transverse carpal ligament attachment at the trapezial ridge without associated fracture has not been previously described. We present a detailed description of a 16-year-old Caucasian male patient treated at our institution, and a second supporting case of a 15-year-old Caucasian male patient with a similar mechanism of injury and diagnostic findings. It is important to be aware of this ligament tear, as it may affect clinical management, is occult on computed tomography, and only detectable on magnetic resonance imaging, stressing the worth of magnetic resonance imaging in the setting of acute wrist trauma.

Ultrasound assessment of the posterolateral elbow ulnohumeral gap in normal subjects with and without posterolateral drawer testing.

Background: Posterolateral rotator instability (PLRI) is the most common pattern of recurrent elbow instability, and current imaging to aid PLRI diagnosis is limited. Thus, we sought to define use of ultrasound (US) to determine normal lateral ulnohumeral joint measurements, with and without posterolateral drawer testing to provide an insight into how US may aid diagnosis. Methods: Sixty elbows were evaluated in thirty healthy volunteers. The lateral ulnohumeral gap (LUHG) was measured with US in the resting position while the posterolateral drawer stress test maneuver was applied. Joint laxity was calculated as the difference between maximum stress and average rest measurements. Two independent readers assessed each elbow with comparison performed between stress and rest positions. Results: Differences in the LUHG were evident between stress and rest conditions (reader 1: P < .0001 and reader 2: P = .0002). At rest, median LUHG values were 2.31 mm and 2.05 mm for readers 1 and 2 respectively, while at stress 2.88 mm and 2.9 mm for readers 1 and 2. Median joint laxity was 0.8 mm for reader 1 and 1.1 mm for reader 2. Pearson correlation was r = 0.457 (absolute intraclass correlation coefficient [ICC] = 0.608) while under stress and r = 0.308 (absolute intraclass correlation coefficient [ICC] = 0.417) at rest. Median joint laxity demonstrated a Pearson correlation of r = 0.161 and absolute intraclass correlation coefficient [ICC] = 0.252. Conclusions: This study demonstrates a dynamic US assessment for PLRI, which aimed to assess the usefulness and feasibility of a laxity measurement after the application of a posterolateral drawer stress maneuver in a healthy population. Although establishing concordance between readers in measuring an LUHG under stress, the utility of a laxity measurement alone is not clear as correlation of measurements is not excellent; hence, an upper limit of normal for the ulnohumeral gap under stress may be more useful. Further evaluation of this technique is required in patients with PLRI.

The reliability and clinical utility of a simple MRI based classification tool for acute scaphoid injuries: the OxSMART.

AIMS: The evidence demonstrating the superiority of early MRI has led to increased use of MRI in clinical pathways for acute wrist trauma. The aim of this study was to describe the radiological characteristics and the inter-observer reliability of a new MRI based classification system for scaphoid injuries in a consecutive series of patients. METHODS: We identified 80 consecutive patients with acute scaphoid injuries at one centre who had presented within four weeks of injury. The radiographs and MRI scans were assessed by four observers, two radiologists, and two hand surgeons, using both pre-existing classifications and a new MRI based classification tool, the Oxford Scaphoid MRI Assessment Rating Tool (OxSMART). The OxSMART was used to categorize scaphoid injuries into three grades: contusion (grade 1); unicortical fracture (grade 2); and complete bicortical fracture (grade 3). RESULTS: In total there were 13 grade 1 injuries, 11 grade 2 injuries, and 56 grade 3 injuries in the 80 consecutive patients. The inter-observer reliability of the OxSMART was substantial (Kappa = 0.711). The inter-observer reliability of detecting an obvious fracture was moderate for radiographs (Kappa = 0.436) and MRI (Kappa = 0.543). Only 52% (29 of 56) of the grade 3 injuries were detected on plain radiographs. There were two complications of delayed union, both of which occurred in patients with grade 3 injuries, who were promptly treated with cast immobilization. There were no complications in the patients with grade 1 and 2 injuries and the majority of these patients were treated with early mobilization as pain allowed. CONCLUSION: This MRI based classification tool, the OxSMART, is reliable and clinically useful in managing patients with acute scaphoid injuries.Cite this article: Bone Jt Open 2022;3(11):913-920.