Comparison of computerized tomography and direct visualization in thoracic pedicle screw placement.

Object: To validate computerized tomography (CT) scanning as a tool to assess the accuracy of thoracic pedicle screw placement, the authors compared its accuracy with that of direct visualization in instrumented cadaveric spine specimens.

Methods: A grading scale was devised to score the placement of the pedicle screw. The grades ranged from 0 to 3 depending on the extent to which the pedicle had been violated.

Epidural injections for the treatment of symptomatic lumbar herniated discs.

Epidural steroid injections are widely used as part of the conservative care for symptomatic herniated lumbar discs. There are studies showing their effectiveness, and some studies demonstrating no clinical benefits. The purpose of this study was to evaluate the effectiveness of epidural steroid injections for patients with symptomatic lumbar disc herniations who were surgical candidates.

Spinal cage retrieval and assessment of biologic response.

Implant retrieval programs have been effective in understanding implant failure and biomaterial compatibility in joint arthroplasty; however, its application has not been extended extensively to the assessment of spinal constructs and implants. The objective of this study is to determine the efficacy of implant retrieval analysis as a standard for the assessment of explanted spinal implants. The limitations of clinical radiographic assessment of fusion through metal interbody devices are also identified.

Clearance of the cervical spine in multitrauma patients: the role of advanced imaging.

The cervical spine is injured in 3% of major trauma patients. Radiographic clearance for injury must be provided efficiently and accurately. There are numerous choices for clearance that are now in clinical practice: lateral radiograph only, 3-view or 5-view cervical-spine (c-spine) series, flexion-extension radiographs, computed tomography (CT) with multiplanar reformations, and magnetic resonance imaging (MRI).

Vertebral osteomyelitis secondary to Pseudallescheria boydii.

Because Pseudallescheria boydii vertebral osteomyelitis is rare and frequently resistant to available antifungal agents, the proper treatment of this lesion has not been defined. To better determine the best treatment of this lesion, the authors evaluated a case P. boydii vertebral osteomyelitis and reviewed the literature.

Dynamic cervical plates: biomechanical evaluation of load sharing and stiffness.

Study Design: An in vitro biomechanical study using a simulated cervical corpectomy model to compare the load-sharing properties and stiffnesses of two static and two dynamic cervical plates.

Objectives: To evaluate the load-sharing properties of the instrumentation with a full-length graft and with 10% graft subsidence and to measure the stiffness of the instrumentation systems about the axes of flexion-extension, lateral bending, and axial torsion under these same conditions.

Summary Of Background Data: No published reports comparing conventional and dynamic cervical plates exist.

Anterior instrumentation of the thoracolumbar spine. A biomechanical comparison.

Study Design: To evaluate the fatigue strength and stiffness of four anterior thoracolumbar fixation devices using a corpectomy model without load-sharing bone graft to test the devices under the worst case scenario of instability.

Objectives: To gain a more thorough understanding of the biomechanical qualities of anterior fixation devices to improve clinical application and design.

Summary Of Background Data: For many surgeons, the anterior approach has become the treatment of choice for patients with compression of the spinal cord, whether it is caused by trauma, tumor, or infection.

Posterior lumbar interbody fusion. A biomechanical comparison, including a new threaded cage.

Study Design: In vitro biomechanical testing was performed on eight lumbar calf spines.

Objectives: To compare the initial stiffness of a standard method of posterior lumbar interbody fusion using structural autograft with the same procedure using additional posterior instrumentation. These constructs also were compared to a new titanium implant.

Case report 803: Gorham's disease (Gorham-Stout syndrome) of scapula.

In summary, a 36-year-old man presented with pain and limited motion in the shoulder. Clinical examination revealed obliteration of normal scapular landmarks in the conspicuous absence of any palpable soft tissue mass. Roentgenograms showed progressive osteolysis of the scapula.

Modified Smith-Robinson procedure for anterior cervical discectomy and fusion.

Fifty-one consecutive patients with cervical radiculopathy or spondylosis were treated with single or multilevel anterior discectomy and fusion using a modified Smith-Robinson procedure. There were 33 single-level fusions, 16 two-level fusions, and 2 three-level fusions. The three modifications included: 1) the endplates at the fusion level were completely removed with a high-speed bur to exposed bleeding cancellous bone in parallel planes; 2) the Caspar distractor (Aesculap, Burlingame, CA) was used to increase distraction and improve visualization; 3) the tricortical autologous iliac crest bone graft was placed in reverse position, that is, with the cortical cross-section facing posteriorly, creating a stabilizing strut in the middle column.

Effects of ankle-foot orthoses on the gait of children.

Gait analysis was performed on five normal children walking barefoot with bilateral double-upright ankle-foot orthoses (AFOs) and with plastic AFOs. When orthoses were worn, walking speed and cadence were reduced and quadriceps EMG timing was prolonged. Changes in lower extremity motions and torques were observed.