Assessment of magnetic resonance imaging in the diagnosis of lumbar spine foraminal stenosis--a surgeon's perspective.

STUDY DESIGN: A 2-part cadaveric study. OBJECTIVES: Part 1: To assess the reliability of a semiquantitative classification system for grading lumbar spine foraminal stenosis and the variability in magnetic resonance imaging (MRI) examinations carried out in different institutions. Part 2: to assess the difference between the foraminal measurements carried out on MRI images and on cadaveric specimens. SUMMARY OF BACKGROUND DATA: There are limited data to suggest that MRI examinations are sensitive or specific for the diagnosis of lumbar spine foraminal stenosis. The effect of the variability in techniques, used by different imaging centers, is not well understood. METHODS: Three fresh, frozen human lumbar spines were examined with 3 different clinical MRI systems. Eight spine surgeons used the MRI images to grade the foramina, on the basis of a previously suggested semiquantitative classification. In addition, the dimensions of all foramina were measured using software available on each of the MRI systems. The dimensions of the specimens' foramina were then measured in situ, graded, and compared with the MRI measurements. RESULTS AND CONCLUSIONS: There was poor intraobserver agreement using the semiquantitative grading system. The parameters associated with the grade of stenosis assigned to the foramen were as follows: (1) the observer doing the grading, (2) the place it was imaged, and (3) the location of the foramen. There was poor correlation between measurements of the foramina carried out on MRI and the specimens.

Case reports: management of large segmental tibial defects using a cylindrical mesh cage.

We report a case series of three patients who sustained open Gustilo-Anderson Type IIIB tibia fractures associated with extensive segmental bone and soft tissue loss. The patients initially were treated with serial wound irrigations, débridements, and external fixation. After the soft tissue envelope was reconstructed successfully, each large segmental bone defect was reconstructed with a cylindrical titanium mesh cage packed with a composite of cancellous allograft and demineralized bone matrix putty and stabilized with a statically locked intramedullary nail. The mean segmental bone loss was 12.2 cm, and all patients had a minimum 1-year followup. One year after reconstruction, radiographs showed stable, well-aligned, healed constructs, and computed tomography images verified the presence of bony ingrowth throughout the cages. All patients were able to ambulate with full weightbearing, and had good ipsilateral knee, hip, and ankle range of motion. This technique seems to be a reasonable alternative for treating large segmental tibial bone defects.

Surgical management of a long segmental defect of the humerus using a cylindrical titanium mesh cage and plates: a case report.

This is a case report of a patient who sustained multiple gunshots resulting in a Gustilo Anderson type IIIB mid-shaft humeral fracture associated with extensive segmental bone and soft-tissue loss. The patient was treated initially by multiple irrigations, wound debridement, and a unilateral external fixator. After the soft tissue healed without infection, the mid-shaft humeral defect of approximately 8 cm segmental bone loss was reconstructed with a cylindrical titanium mesh cage packed with a composite of cancellous allograft and demineralized bone matrix putty and stabilized with limited contact dynamic compression plates. At 13 months follow-up, plain radiographs demonstrated a healed construct with good alignment, and computed tomography images demonstrated bony in-growth through the cage. The patient had full range of motion at the shoulder and the elbow. This technique may be a reasonable alternative when treating large segmental bone defects of the humerus.