Surgical observation of the agenesis of the foramen of Magendie

We report a young girl who presented with headache and back pain. Dynamic MRI revealed no cerebrospinal egress from the median aperture (Foramen of Magendie) of the fourth ventricle and syringomyelia. A posterior cranial fossa exploration was performed and agenesis of the median aperture was observed. Following surgical penetration of the posterior aspect of the fourth ventricle and at the most recent follow-up examination, this patient’s syringomyelia had resolved, as had her symptoms. Agenesis of the foramen of Magendie may be a rare cause of inhibition of normal cerebrospinal egress from the fourth ventricle with resultant syringomyelia

Klippel-Feil anomaly with associated rudimentary cervical ribs in a human skeleton: case report and review of the literature

Anomalies of the cervical spine are intriguing anatomically and often come to clinical attention. Fusion of one or more cervical vertebral segments, the Klippel- Feil anomaly (KFA), often causes increased motion at the vertebral segments superior to and inferior to the fused level with a resultant premature wear of these joints. We report an adult male skeleton with fusion of his C6 and C7 vertebral bodies (Type II KFA). A remnant of the intervertebral disc space was noted and bilateral rudimentary cervical ribs were observed emanating from the C7 vertebrae. Excessive joint degeneration was noted between the vertebral bodies of C5 and C6. Following our review of the literature and case report, it appears that there is an increased incidence of the presence of cervical ribs in KFA. We review the literature for coexistent KFA and cervical ribs and discuss their dysembryology

The most common anatomical sites of arterial injury in the extremities: a review of 75 angiographically-proven cases

The incidence of vascular injury has increased worldwide. In an attempt to quantitate the specific arteries most commonly involved in the extremities, we reviewed 75 patients with extremity trauma who were evaluated with angiography (DSA, digital subtraction angiography). The majority of these injuries were related to motor vehicle accidents (93.3%). The mean age of these patients was 28.16 ± 11.14 years, 94.7% of these patients being male. The ratio of upper to lower extremity arterial trauma was 12 to 86. A total of 99 arterial injuries were detected angiographically. Simultaneous injuries to two and three extremity arteries were identified in 13.3% and 9.3% of patients respectively. The most common arteries injured were the anterior tibial, femoral, peroneal, and popliteal arteries. Associated fractures were present in 86.7% of patients. These data may prove useful to the clinician who evaluates post-traumatic injuries of the extremities

Type I split cord malformation with an usual bony morphology

Variations in the configuration of the bony septum found in patients with split cord malformations are rare. We report the seemingly rare occurrence of a midline bony septum that ended posteriorly as a fully formed bony spinous process. We speculate that this variation is due to misplaced mesodermal cells associated with the primitive endomesenchymal tract during approximately the third week of foetal life. The clinician that manages these patients may wish to consider this rare morphology and avoid excessive manipulation of such a process, which could potentially injure an underlying hemicord

The subanconeus muscle

There is a paucity of information in the extant literature regarding the detailed anatomy of the subanconeus (articularis cubiti) muscle. Our current study seeks to elucidate further the presence, morphology, and potential function of this muscle. Eighteen cadaveric upper extremities underwent dissection of their posterior elbow joint capsule with special attention to any fibres attaching to it from the triceps brachii muscle. We found that all specimens had various amounts of muscular attachment of the medial head of the triceps into the posterior joint capsule. It was noted that the highest concentration of fibres was into the joint capsule near the groove for the ulnar nerve. No specimen was found to have a distinct muscle belly associated with these connections to the joint capsule. On all sides these fibres were simply deeper attachments of the medial head of the triceps brachii muscle. Following tension on these deeper fibres retraction of the joint capsule was not noted but rather compression of the capsule. We would speculate on the basis of our study that these fibres of the medial head of the triceps brachii muscle do not represent a separate muscle per se and do not retract the posterior elbow joint capsule with extension of the forearm as has been theorised. It is possible that compression of the posterior elbow joint capsule from these deeply placed fibres of the triceps brachii restricts the elbow fat pad from being displaced and allows it to cushion the contact made between the olecranon process and the olecranon fossa

Accessory venous sinus of Hyrtl

Variations of the intracranial venous sinuses are important to the surgeon during intraoperative procedures and to the clinician during imaging interpretation. We report a male cadaver found to have a rare venous sinus variation. In all likelihood, this sinus corresponded to the rarely reported accessory venous sinus of Hyrtl. The sinus was approximately 5 mm in width and traveled from the sphenoparietal sinus anteriorly to the veins, draining into the foramen spinosum (i.e. the middle meningeal veins) posteriorly. No other variations or obvious pathology were identified intracranially or extracranially. Knowledge of such a venous variation may be of use to the clinician

Popliteal artery aneurysms: a review

Popliteal artery aneurysms (PAAs) are the most common form of peripheral arterial aneurysms. The popliteal artery is the continuation of the femoral artery and represents the major source of blood to the leg. Thrombus formation as a result of PAA may reduce blood flow, leading to limb-threatening ischemia and potential limb amputation. Popliteal artery aneurysms are predominantly seen in males (95-99% of cases), presumably owing to their predisposition for arteriosclerosis, which is also a major factor for PAA predisposition. Additionally, it is not uncommon to see an abdominal aortic aneurysm associated with a PAA (30-50% of cases) or bilateral presentation of PAA (~50% of cases). A consequence of a PAA and thrombus located in the popliteal fossa is an inflammatory reaction, potentially involving adjacent structures in the fossa. This may present clinically as pain in the leg and/or edema. Treatment of PAA involves either a conservative management protocol or a more aggressive intervention such as surgery. Proponents of conservative management will regulate the diameter of the aneurysm by ultrasound, while those in favor of surgical intervention will repair the aneurysm through a number of open surgical methods or by endovascular stent grafting. This review summarizes the historical points related to PAA and analyzes the pertinent anatomical implications, clinical findings and treatment methods for PAA

Levator claviculae: a case report and review of the literature

The levator claviculae is an uncommon anatomical variant found in the posterior cervical triangle. In this report we present a 78-year-old man with this muscular variation, which was found during gross anatomical dissection. While sites of insertion and origin have been variable, in the present case the muscle originated from the left transverse processes of C3 and C4, and inserted onto the lateral third of the ipsilateral clavicle. Clinical considerations of this variant anatomy are of interest, as they may present in patients as a supraclavicular mass and may also mimic pathology on cross-sectional imaging

A rare variation of the posterior cranial fossa: duplicated falx cerebelli, occipital venous sinus, and internal occipital crest

Folds of the meningeal layer of the dura mater, the falx cerebri and tentorium cerebelli, traverse the vertebrate intracranial cavity and thus compartmentalise the brain. The falx cerebelli, another dural fold, is found in the posterior cranial fossa and attaches to the inferior aspect of the tentorium cerebelli and to the internal occipital crest. We present a case of a duplicated falx cerebelli, occipital venous sinus and internal occipital crest that was detected upon routine dissection of a male cadaver. Since haemorrhage of a dural venous sinus can be a fatal complication of posterior cranial fossa surgery, knowledge of venous sinus variations in this region may prevent unpredictable complications during intracranial procedures

An unusual muscle of the wrist with potential compression of the ulnar nerve

During routine cadaveric dissection of the upper extremity an unusual muscle was discovered arising from the tendon of the flexor carpi ulnaris and inserting into the muscle belly of the flexor digiti minimi. The muscle’s course was superficial to the ulnar nerve and artery in Guyon’s canal. We review the literature regarding such muscle variations and discuss the potential for compression of the ulnar nerve by such muscles