Journal of orthopaedic research : official publication of the Orthopaedic Research Society
-
Recent studies have reported that low-intensity pulsed ultrasound (LIPUS) stimulates cell proliferation and proteoglycan production in rabbit intervertebral disc cells, and moreover promotes the secretion of MCP-1 (monocyte chemotaxis protein-1) from macrophages in a disc organ culture model. These findings suggest the possible application of LIPUS for biological repair of disc degeneration and herniation. Although the mechanisms involved are not well understood, several cytokine pathways may play a role. ⋯ This was confirmed at the gene level by RT-PCR in nucleus pulposus cells and macrophages after stimulation with LIPUS. Quantitative evaluation of these proteins by ELISA showed higher levels in nucleus pulposus cells and macrophages stimulated by LIPUS than in controls. These results showed that LIPUS stimulation significantly activated TIMP-1 and MCP-1 in nucleus pulposus cells and macrophages at both the protein and gene levels, suggesting that LIPUS may be a promising supplemental treatment for intervertebral disc herniation.
-
Comparative Study
Comparative stability of perpendicular versus parallel double-locking plating systems in osteoporotic comminuted distal humerus fractures.
In distal humerus fractures, the restoration of stability is important to allow early mobilization and hence more favorable functional outcomes. In this article, we compare the biomechanical stability of perpendicular and parallel locking plating systems for the internal fixation of AO Type C2 distal humerus fractures in osteoporotic bone. Fractures were simulated in paired cadaveric bones and fixed using either the perpendicular 3.5 mm LCP distal humerus plating system (Synthes; Sydney, Australia) or the parallel Mayo Clinic Congruent elbow plate system (Acumed; Hillsboro, OR), using locking screws in both systems. ⋯ A disadvantage of the parallel locking plate system was wear debris produced by its tapping system. In summary, the biomechanical findings of this study suggest that both locking plate systems allow early mobilization of the elbow in patients with osteoporotic bone following fixation of a comminuted distal humerus fracture. However, the parallel locking system showed improved stability compared with the perpendicular locking system, and therefore may be more indicated.