The direct muscular origin of the semitendinosus: a pitfall in categorization of proximal hamstring tendon tears.

The ischial origin of the hamstring musculature is complex. While the conjoint tendon and semimembranosus are commonly discussed and understood by radiologists, there is a lesser-known origin of the semitendinosus along the inferior and medial surface of the ischium in the form of a broad direct muscular connection. This secondary origin is infrequently described in the radiology literature and is a potential pitfall during grading of semitendinosus injuries if the interpreting physician is unaware of its presence. In a proximal hamstring tendon tear, the direct muscular origin of the semitendinosus can be spared, torn along with the conjoint tendon, or remain intact and contribute to a vertical shearing injury of the semitendinosus myotendinous junction. Detailed knowledge of this anatomy and its imaging appearance in the setting of injury enables the reader to correctly diagnose these unique hamstring injuries.

The double corpus luteum: A novel sonographic sign of heterotopic pregnancy.

Heterotopic pregnancy is a rare and highly morbid condition with simultaneous intrauterine and extra-uterine pregnancies. The early diagnosis of heterotopic pregnancy is difficult, owing to rarity of the condition and nonspecific clinical and laboratory findings. This case report introduces the "double corpus luteum" sign, a new sonographic and magnetic resonance imaging sign which is easily detectable and should raise the index of suspicion for heterotopic pregnancy. We present a surgically confirmed spontaneous heterotopic and angular pregnancy in a young woman without risk factors or assisted reproductive therapy to illustrate the utility of this novel sign.

Successful non-operative management for atlanto-occipital dislocation resulting in spinal cord contusion in a patient with atlanto-occipital assimilation and severe Chiari I malformation.

BACKGROUND: Atlanto-occipital dislocation (AOD) is a rare, highly morbid, and highly lethal injury that results from high-energy trauma and almost universally requires operative management for satisfactory outcomes. It can be difficult to identify the severity of injury at the time of presentation, and when diagnosis is delayed outcomes worsen significantly. Anatomic anomalies of the craniovertebral junction may further complicate its detection. When such anomalies are present either singly or in combination, they are known to cause space constraints which may increase the likelihood of spinal cord injury. Given that such anomalies and AOD are rare, few examples of patients with both are reported in the literature. Furthermore, it is not clear in what way patient management may be impacted in this context. CASE DESCRIPTION: We will present a unique case of an 18-year-old patient with traumatic AOD and an intact neurologic examination who was found to have atlanto-occipital assimilation (AOA), platybasia, basilar invagination, and severe Chiari I malformation, who was treated effectively with non-operative management. CONCLUSION: Our case demonstrates the successful application of a non-operative treatment strategy in a carefully selected patient with AOD in the context of AOA.

COVID-19 in Patients With Hematologic-Oncologic Risk Factors: Complications in Three Patients.

The novel COVID-19 infection has demonstrated a spectrum of complications involving vascular, inflammatory, infectious, and metabolic conditions. These complications range from mild loss of smell to more severe acute respiratory distress syndrome (ARDS). Patients with more severe complications often require sedation and mechanical ventilation. Growing research has revealed the role of active malignancy and disease-in-remission status as possible risk factors contributing to the morbidity and mortality in COVID-19 patients. In our descriptive case series, we present three unique cases of complicated COVID-19 infection in patients with hematologic-oncologic risk factors and review the imaging features of their complications. The first patient was a 33-year-old male with sickle cell trait who developed rhabdomyolysis and myonecrosis of the paraspinal muscle in the setting of a physical fitness test; he subsequently developed an abscess at this site, presumably exacerbated by the hypoxemic state of his COVID-19 pneumonia. Our second patient was a 37-year-old male with COVID-19 pneumonia and a history of stage IV Non-Hodgkin's lymphoma in remission who developed spontaneous pneumomediastinum in the absence of positive pressure ventilation. The third COVID-positive patient was a 54-year-old male with a past medical history significant for grade 1 follicular non-Hodgkin's lymphoma in remission with sputum culture positive for mycobacterium avium complex and bronchoscopy positive for candida growth. 18-FDG/PET imaging was performed and demonstrated diffuse intense uptake throughout the lungs reflecting both the COVID-19 pneumonia and the multimicrobial superinfection.

Clinical considerations of the glandular branch of the lacrimal artery.

The lacrimal artery is classically described as a branch of the ophthalmic artery supplied by the internal carotid. In this study, 25 orbits were dissected to identify variations in glandular branching and to compare them to previously published accounts. The glandular branching patterns of the lacrimal artery fall into two categories, those that branch (56%) and those that do not branch (44%). We found the medial and lateral glandular branches to be equal in diameter with a divergence of 2.67-40.58 mm proximal to the gland parenchyma. The long glandular branches run alongside the superolateral aspect of the orbit. The lateral branch runs lateral to the lateral rectus muscle. The medial branch runs superomedial to the lateral rectus muscle and lateral to the superior rectus muscle. In relation to the lacrimal gland, the medial branch enters the superior aspect of the gland parenchyma and the lateral branch enters its inferior aspect. The average branch lengths were 17.88 mm (medial) and 13.51 mm (lateral) as measured with a Mitutoyo Absolute 1/100 mm caliper. We could not confirm the existence of a third branch supplying the lacrimal gland, as posited by other authors. The key finding in this study is that the lacrimal gland is predominantly supplied by two significant arterial branches, both of which must be identified during procedures involving the lateral orbit.

Patterns of innervation of the lacrimal gland with clinical application.

Parasympathetic stimulation of the lacrimal gland is responsible for tear production, and this innervation originates from fibers conveyed in the facial nerve. After synapse in the pterygopalatine ganglion, postsynaptic parasympathetic fibers travel within the zygomatic and zygomaticotemporal nerves (ZTN) into the orbit. As described in most anatomy texts, ZTN communicates with the lacrimal nerve (LN) posterior to the gland and then secretomotor fibers enter the gland. This study was performed to gain a better understanding of the innervation of the lacrimal gland. Seventeen cadaver heads were bisected for a total of 34 sides, which then underwent dissection of the superolateral orbital region to observe the course for the LN and ZTN. Three variations of the course of the LN and ZTN were found. In 20 (60.6%) dissections it was documented that the ZTN entered directly into the lacrimal gland with no communication with the LN. In 12 (36.4%) of the bisected heads, ZTN had both a direct connection into the gland and a communicating branch with the LN. In only one (3.0%) bisected head, ZTN communicated with the LN before entering the gland as it is commonly described in anatomy texts. Our study reveals that the ZTN usually takes a different course than is classically described in most anatomy textbooks. A greater understanding of the typical course these nerves take may help surgeons identify them more easily and avoid damaging them.