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Background:. Accumulating evidence suggests that lithium influences mesenchymal stem cell (MSC) proliferation and osteogenic differentiation. As decreased bone formation in femoral heads is induced by glucocorticoids (GCs), we hypothesized that lithium has a protective effect on GC-induced osteonecrosis of femoral heads (ONFH). Methods:. A rat ONFH model was induced by methylprednisolone (MP) and the effect of lithium chloride on the models was evaluated. Micro-computed tomography (CT)-based angiography and bone scanning were performed to analyze the vessels and bone structure in the femoral heads. Hematoxylin and eosin and immunohistochemical staining were performed to evaluate the trabecular structure and osteocalcin (OCN) expression, respectively. Bone marrow-derived MSCs were isolated from the models, and their proliferative and osteogenic ability was evaluated. Western blotting and quantitative real-time polymerase chain reaction were performed to detect osteogenic-related proteins including Runx2, alkaline phosphatase, and Collagen I. Results:. Micro-CT analysis showed a high degree of osteonecrotic changes in the rats that received only MP injection. Treatment with lithium reduced this significantly in rats that received lithium (MP + Li group); while 18/20 of the femoral heads in the MP showed severe osteonecrosis, only 5/20 in the MP + Li showed mild osteonecrotic changes. The MP + Li group also displayed a higher vessel volume than the MP group (0.2193 mm3vs. 0.0811 mm3, P

Background: Hook plate (HP) is popularly used for acute and severely displaced acromioclavicular (AC) dislocations. However, subacromial impingement and acromion osteolysis induced by transarticular fixation are notorious. The current case-control study was to compare transarticular fixation by HP to coracoclavicular (CC) stabilization by single multistrand titanium cable (MSTC).Methods: Between January 2006 and August 2009, 24 patients with acute AC dislocations were surgically treated by open reduction and transarticular fixation with HP. These patients were matched to a series of 24 patients, who were managed by CC stabilization with MSTC in the same period. All AC dislocations were graded as Rockwood type V. Implant was removed 8-12 months after the primary operation in all patients, and 12 months at least were needed to assess the maintenance of AC joint. Functional results were evaluated before implant removal as well as in the last follow-up based on Constant-Murley criteria.Results: There were no differences of demographic data including age, dominant gender and side, injury-to-surgery interval, operation time and follow-up period. In terms of functionality, Constant score was 95.8 ± 4.1 in MSTC group, while 76.7 ± 8.0 in HP group before implant removal (P < 0.001). In detail, MSTC was superior to HP in pain, ROM and activities. Constant score was significantly improved to 86.1 ± 5.7 after hardware removal for patients in HP (P < 0.001). Degenerative change of acromioclavicular joint presented in 16 patients (66.7%) in patients treated by HP, while it was found in only 3 patients (12.5%) treated by MSTC (P < 0.001).Conclusions: MSTC is superior to HP for the treatment of Rockwood type-V acromioclavicular dislocation both before and after removal of the implant. Hardware removal is of great benefits for functional improvement in patients treated by HP. [ABSTRACT FROM AUTHOR]