Surgical Resection of Bertolotti Syndrome.

Bertolotti syndrome is the association of lumbosacral transitional vertebrae and low back pain or sciatica. Lumbosacral transitional vertebrae are vertebrae with large transverse processes that (1) articulate or fuse with the sacrum or ilium and (2) have a caudal disc space. Bertolotti syndrome is relatively common, with an incidence of 4.

Three-Dimensional Printed Patient Models for Complex Pediatric Spinal Surgery.

Pediatric spinal deformity surgeries are challenging operations that require considerable expertise and resources. The unique anatomy and rarity of these cases present challenges in surgical training and preparation. We present a case series illustrating how 3-dimensional (3-D) printed models were used in preoperative planning for 3 cases of pediatric spinal deformity surgery.

Long-term Results of Spine Stapling for AIS to Skeletal Maturity and Beyond.

Background: We looked at long-term follow-up of spine stapling with Nitinol Staples. This was a cohort of all adolescent idiopathic scoliosis (AIS) patients with curves at high risk to progress based on curve magnitude, premenarchal status in all females, failure of brace treatment, and skeletal immaturity.

Methods: This is a single surgeon retrospective review of consecutive AIS patients treated with Nitinol staples for progressive scoliosis.

Spinopelvic Parameters: Lumbar Lordosis, Pelvic Incidence, Pelvic Tilt, and Sacral Slope: What Does a Spine Surgeon Need to Know to Plan a Lumbar Deformity Correction?

The pelvic incidence defines the amount of lordosis required in the lumbar spine, and a lumbar lordosis within 11° of the pelvic incidence defines alignment of the lumbo-pelvic region. Pelvic tilt is a compensatory mechanism that allows patients to achieve sagittal balance in the setting of decreased lumbar lordosis with the primary compensatory mechanisms being hip extension and knee flexion. Planning an adult lumbar deformity operation requires a comprehensive history and physical examination and thorough radiographic evaluation with the goal of restoring alignment between the pelvic incidence and lumbar lordosis and restoring a normal pelvic tilt.

Sagittal Alignment Two Years After Selective and Nonselective Thoracic Fusion for Lenke 1C Adolescent Idiopathic Scoliosis.

Study Design/setting: Matched cohort.

Objective: To evaluate thoracic and thoracolumbar sagittal Cobb angles in patients undergoing either selective thoracic fusion (STF) or nonselective thoracic fusion (NSTF) for Lenke 1C adolescent idiopathic scoliosis (AIS).

Summary Of Background Data: The Lenke classification is used to guide fusion levels in AIS.

Lumbar clinical adjacent segment pathology: predilection for proximal levels.

Study Design: Retrospective case series.

Objective: To evaluate reoperations for lumbar adjacent segment pathology (ASP) during a 10-year period.

Summary Of Background Data: ASP after lumbar arthrodesis is an important clinical problem.

Minimally invasive approaches to the cervical spine.

Minimally invasive approaches and operative techniques are becoming increasingly popular for the treatment of cervical spine disorders. Minimally invasive spine surgery attempts to decrease iatrogenic muscle injury, decrease pain, and speed postoperative recovery with the use of smaller incisions and specialized instruments. This article explains in detail minimally invasive approaches to the posterior spine, the techniques for posterior cervical foraminotomy and arthrodesis via lateral mass screw placement, and anterior cervical foraminotomy.

Minimally invasive cervical spine foraminotomy and lateral mass screw placement.

Study Design: This technique article describes accomplishing multilevel posterior cervical decompression and lateral mass screw placement through a tubular retraction system.

Objective: Multilevel foraminotomy and instrumented fusion using lateral mass screw fixation can be achieved through a minimally invasive technique using specialized retractors and intraoperative fluoroscopic imaging.

Summary Of Background Data: Minimally invasive surgical techniques have been adapted to the cervical spine with good results.

Disappointing short-term results with the DePuy ASR XL metal-on-metal total hip arthroplasty.

Outcomes of ultralarge-diameter femoral heads used in metal-on-metal (MOM) total hip arthroplasty (THA) are relatively unknown. This study reports on early failures of the ASR XL (Depuy, Warsaw, Ind) and assesses whether a correlation with cup positioning exists. A retrospective review of 70 consecutive MOM THAs with ultralarge-diameter femoral head and monoblock acetabular component was conducted.

Reconstruction plates for stabilization of mid-shaft clavicle fractures: differences between nonlocked and locked plates in two different positions.

Reconstruction plates permit contouring to the irregular anatomic shape of the clavicle. This study evaluated the biomechanical stability of locking and nonlocking clavicle reconstruction plates for treating midshaft, transverse fractures, comparing anterior-inferior to superior plate position. Twenty-four synthetic clavicles with mid-shaft fractures were repaired with either a locking or nonlocking clavicle reconstruction plate in either the anterior-inferior or superior plate position (n = 6/group).

Biomechanical evaluation of clavicle fracture plating techniques: does a locking plate provide improved stability?

Objectives: To evaluate the biomechanical properties of both plate location (superior versus anterior-inferior) and plate type Small Fragment Contourable Dual Compression Plate (CDCP) versus 3.5 mm Universal Locking System Contourable Dual Compression Plate (Locked CDCP) in a synthetic midshaft transverse clavicle fracture model.

Methods: Twenty-four pre-osteomized synthetic clavicles were repaired with either CDCP or locked CDCP technology 3.

A reversible molecular valve.

In everyday life, a macroscopic valve is a device with a movable control element that regulates the flow of gases or liquids by blocking and opening passageways. Construction of such a device on the nanoscale level requires (i) suitably proportioned movable control elements, (ii) a method for operating them on demand, and (iii) appropriately sized passageways. These three conditions can be fulfilled by attaching organic, mechanically interlocked, linear motor molecules that can be operated under chemical, electrical, or optical stimuli to stable inorganic porous frameworks (i.

Single-walled carbon nanotube based molecular switch tunnel junctions.

This article describes two-terminal molecular switch tunnel junctions (MSTJs) which incorporate a semiconducting, single-walled carbon nanotube (SWNT) as the bottom electrode. The nanotube interacts noncovalently with a monolayer of bistable, nondegenerate [2]catenane tetracations, self-organized by their supporting amphiphilic dimyristoylphosphatidyl anions which shield the mechanically switchable tetracations from a two-micrometer wide metallic top electrode. The resulting 0.

Redox-controllable amphiphilic [2]rotaxanes.

With the fabrication of molecular electronic devices (MEDs) and the construction of nanoelectromechanical systems (NEMSs) as incentives, two constitutionally isomeric, redox-controllable [2]rotaxanes have been synthesized and characterized in solution. Therein, they both behave as near-perfect molecular switches, that is, to all intents and purposes, these two rotaxanes can be switched precisely by applying appropriate redox stimuli between two distinct chemomechanical states. Their dumbbell-shaped components are composed of polyether chains interrupted along their lengths by i) two pi-electron rich recognition sites-a tetrathiafulvalene (TTF) unit and a 1,5-dioxynaphthalene (DNP) moiety-with ii) a rigid terphenylene spacer placed between the two recognition sites, and then terminated by iii) a hydrophobic tetraarylmethane stopper at one end and a hydrophilic dendritic stopper at the other end of the dumbbells, thus conferring amphiphilicity upon these molecules.

Dynamic chirality: keen selection in the face of stereochemical diversity in mechanically bonded compounds.

The template-directed syntheses, employing bisparaphenylene-[34]crown-10 (BPP34C10), 1,5-dinaphthoparaphenylene-[36]crown-10 (1/5NPPP36C10), and 1,5-dinaphtho-[38]crown-10 (1/5DNP38C10) as templates, of three [2]catenanes, whereby one of the two bipyridinium units in cyclobis(paraquat-p-phenylene) is replaced by a bipicolinium unit, are described. The crude reaction mixtures comprising the [2]catenanes all contain slightly more of the homologous [3]catenanes, wherein a "dimeric" octacationic cyclophane has the crown ether macrocycles encircling the alternating bipyridinium units with the bipicolinium units completely unfettered. X-ray crystallography, performed on all three [2]catenanes and two of the three [3]catenanes reveals co-conformational and stereochemical preferences that are stark and pronounced.