The S1 dorsal foramen: Nuances of anatomy.

Background: Access to the dorsal S1 neural foramen is frequently performed, but can be challenging.

Purpose: To report previously undescribed nuances of dorsal S1 foraminal anatomy, including a bony flange that may obstruct access to the foramen.

Methods: Fluoroscopic - advanced imaging correlations of the S1 foraminal aperture were performed.

Subperiosteal Schwannoma of the Mid-Tibia: A Cause of Long-Lasting Unexplained Pain.

Schwannomas are benign tumors affecting the nerve sheath. Their presence in the subperiosteal region is extremely rare. We report a case of a 66-year-old male patient with a 10-year history of unexplained pain of the anterior leg that turned out to be caused by a subperiosteal schwannoma of the mid-tibia.

Simultaneous Bilateral Avascular Necrosis of the Femoral Heads Associated With Cocaine Use.

We present a case of a 38-year-old female patient, presenting with debilitating simultaneous bilateral avascular necrosis of the femoral head (AVNFH) 10 years after cocaine detoxification, making her wheelchair-bound for six months. This case is reported for the rarity of association of cocaine with AVNFH, and for the unique fact of the simultaneous bilateral condition occurring a long time after cocaine ingestion in the absence of other important risk factors. This report postulates cocaine as a possible cause of bilateral AVNFH, which can increase the index of suspicion of this pathology, allowing early diagnosis and better outcomes.

Synovial Cysts Confounding Access to the Dorsal S1 Neural Foramen in Transforaminal Epidural Steroid Injections.

Objectives: The S1 dorsal foramen is the route for 30% of lumbar transforaminal epidural injections; it is therefore important to identify structures impeding S1 foraminal access. The study objective was to characterize the imaging findings, prevalence, and anatomic origin of synovial cysts presenting within the S1 neural foramen.

Methods: A case series (N = 14) established imaging characteristics of S1 synovial cysts.

Imaging Determinants of Clinical Effectiveness of Lumbar Transforaminal Epidural Steroid Injections.

Objective: To examine associations between imaging characteristics of compressive lesions and patient outcomes after lumbar transforaminal epidural steroid injections (TFESIs) stratified by steroid formulation (solution versus suspension).

Design/subjects: Retrospective observational study, academic radiology practice. A 516-patient sample was selected from 2,634 consecutive patients receiving lumbar TFESI for radicular pain.