KEY FACTS You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Synonym: Ossiculum terminale persistens Persistence of unfused odontoid tip ossification center into adulthood You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Latin: “Little posterior bridge” Synonyms: Arcuate foramen, sagittale foramen, canalis vertebralis, retroarticular canal, retroarticular/retrocondylar vertebral artery ring, upper retroarticular foramen, and atlantal posterior foramen You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Synonyms: Atlantooccipital assimilation, atlantal assimilation, “occipitalization” Nonresegmentation of proatlas sclerotome → failure of C1 to correctly segment from occipital bone You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Congenital C2-C3 vertebral segmentation failure You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Intrathecal baclofen (ITB) Intraspinal drug delivery (IDD) Malfunction or malposition of pump or catheter delivery system Pathology ITB used for treatment of spasticity Typically used in children with severe quadriplegic pattern cerebral palsy IDD system therapy widely utilized in patients with intractable, nonmalignant, and malignant pain Epidural analgesia trial may be conducted to document efficacy prior to implantation of permanent intrathecal drug delivery…

KEY FACTS Terminology Spinal fusion surgery recommended when curve magnitude > 40-45° for adolescent idiopathic scoliosis Adult scoliosis presents with lumbar back ± leg pain, L3-L4 rotatory subluxation, L4-L5 tilt, and L5-S1 disc degeneration on radiographs Imaging Radiographs Main thoracic, thoracolumbar, and lumbar curves should be assessed for structural characteristics 36′ standing anteroposterior & lateral radiographs & supine side-bending radiographs In adult scoliosis, assess for degenerated…

KEY FACTS Terminology Synonyms: Interspinous posterior decompression, interspinous distraction device, interspinous spacer device (ISD), interspinous implant Dynamic stabilization alters movement & load transmission of spinal motion segment without fusion of segment Interspinous spacing device places stenotic segment in slight flexion while preventing extension Imaging Radiographs & CT helpful to evaluate interspinous location Assess for fractures Pathology Lumbar neurogenic claudication symptoms are exacerbated during extension, relieved during…

KEY FACTS You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

KEY FACTS Terminology Pedicle screw: Most common implant in spine surgery High rigidity and resistance to pullout Engages all 3 columns of spine Resists motion in all 3 directions Used in wide variety of procedures Maintain spine alignment while fusion occurs Maintain reduction after fracture Maintain correction of deformity Procedure 3 common techniques Free hand Fluoroscopy based Computer assisted (navigation) either 2D or 3D – Safe…

KEY FACTS Terminology Methods to stabilize subaxial cervical spine with posterior element constructs Procedure Interspinous wiring (Rogers 1942) Simple and low risk Sublaminar wiring Attach to onlay graft material or rods Facet wiring (Callahan 1977) Facet capsules opened and holes drilled at each level Clamps (Tucker 1975) Narrows spinal canal similar to sublaminar wires Lateral mass screws and plates (Roy-Camille) Immediate stability with no need for…

KEY FACTS Terminology Cages used to reconstruct anterior spinal column after corpectomy In vivo expansion of cage permits optimal fit and correction of deformity Imaging Cylindrical metallic prosthesis along craniocaudal span of vertebral body Radiography & CT Difficult to assess fusion Assess stability of expandable cages (EC) Determine EC-related complications MR Can be somewhat obscured by magnetic susceptibility artifact Best to evaluate thecal sac and neural…

KEY FACTS Terminology Instrumentation in fusion surgery designed to stabilize, not replace, spinal bony elements Imaging Postoperative imaging: Assess progress of osseous fusion, confirm correct positioning & integrity of instrumentation, detect suspected complications (e.g., infection or hematoma), & detect new disease or disease progression Radiographs Noninvasive, most common for assessment of fusion Instrumentation break or periimplant lucency CT Modality of choice for imaging bony detail to…

Regulation Once a device becomes FDA approved and available, the physician can use the device in any manner (off-label) that he/she desires if it is in the best interest of the patient and supported by objective and appropriate peer-reviewed scientific and clinical information. This is termed the “practice of medicine.” No investigational device exemption or institutional review board review is needed in these types of cases.…

KEY FACTS Terminology CT: Beam-hardening artifact and blooming artifact MR: Magnetic susceptibility artifact Image degradation related to metal prostheses/implants Imaging CT: Artifact from metal hardware related to image reconstruction algorithm, tube current, x-ray kilovolt peak, pitch, hardware composition, shape, & location Beam-hardening artifact is dark banding between dense objects, such as bone Bloom artifacts result of partial volume effects or areas of photon starvation propagated by…

KEY FACTS Terminology Peridural fibrosis Some degree of peridural fibrosis along margin of thecal sac is typical finding following discectomy Edema and tissue disruption at discectomy site particularly conspicuous in first 6 weeks postoperatively Can simulate disc residual/recurrent disc herniation Scarring has been implicated with nerve root irritation in failed back surgery syndrome Postoperative fluid collection Fluid collection in operative bed is not uncommon in immediate…

KEY FACTS Terminology Substantial imaging overlap in routine early postoperative findings vs. surgical complications Early postoperative imaging not routinely obtained Edema, granulation tissue at operative site may simulate residual/recurrent disc herniation Marrow changes and fluid associated with intervertebral fusion may simulate appearance of spondylodiscitis You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a…

Terminology Radiographic measurement techniques, skull base craniometry, skull base lines Pathology-based Imaging Issues This chapter provides a broad summary of the varied measurement techniques used to evaluate the spine. The main focus for the reader should be the tables and the multiple schematics that define the variously named lines and angles. These summarize the classic measurement techniques for the skull base and rheumatoid disease as well…