There was a significant difference in the degree of relaxation of the adductor pollicis muscle and the vocalis muscle. The laryngeal muscles exhibited a shorter response time than the adductor pollicis and recovered more quickly. These results confirm the feasibility of intra-operative neuromonitoring of the recurrent laryngeal nerve during neuromuscular blockade.

Background: Mesenchymal stem/stromal cells (MSCs) can replenish the aged cells of the musculoskeletal system in adult life. Stem cell exhaustion and decrease in their regenerative potential have been suggested to be hallmarks of aging. Here, we investigated whether muscle-and bone-derived MSCs of patients with osteoarthritis and osteoporosis are affected by this exhaustion, compared to healthy donors. Methods: Patients with primary osteoarthritis, femoral neck fractures due to osteoporosis, and healthy donors (controls) were included. MSCs were isolated from the skeletal muscle and subchondral bone from each patient and compared using ex vivo and in vitro analyses, including immunophenotyping, colony-forming unit fibroblast assays, growth kinetics, cell senescence, multilineage potential, and MSC marker gene expression profiling. Results: Freshly isolated cells from muscle from patients with osteoarthritis showed a lower proportion of CD45/ CD19/CD14/CD34-negative cells compared to patients with osteoporosis and healthy donors. Freshly isolated muscle cells from patients with osteoarthritis and osteoporosis also showed higher clonogenicity compared to healthy donors. MSCs from both tissues of osteoarthritis patients showed significantly reduced osteogenesis and MSCs from the bone also reduced adipogenesis. Chondrogenic pellet diameter was reduced in bone-derived MSCs from both patient groups compared to healthy donors. A significant positive correlation was observed between adipogenesis and CD271 expression in muscle-derived MSCs. CD73 was significantly lower in bone-derived MSCs from osteoarthritis patients, compared to osteoporosis patients. Gene expression profiling showed significantly lower expression of MSC marker gene leptin receptor, LEPR, previously identified as the major source of the bone and adipocytes in the adult bone marrow, in bone-derived MSCs from patients with osteoarthritis in comparison with osteoporotic patients and healthy donors.

The role of bone marrow adipocytes in bone tissue is not yet understood. Adipocytes express enzymes for metabolism of free fatty acids and adipokines such as adiponectin, which have been shown to exert different effects on bone cells. Our aim was to find out whether triglyceride (TG) metabolism in bone tissue is associated with osteoblast and osteoclast differentiation by gene expression analysis of lipoprotein lipase (LPL), hormone sensitive lipase (HSL), fatty acid synthase (FASN), adiponectin, RUNX2, RANK, RANKL and OPG. Bone tissue was obtained from patients undergoing hip arthroplasty due to osteoporosis (OP) (50) or osteoarthritis (OA) (48) or from healthy autopsy controls (14). Lower bone mineral density and microstructural parameters were observed in OP compared to OA. The FASN expression did not differ between groups suggesting similar de novo lipogenesis. Lower LPL and HSL in OP suggest lower FFA release and uptake in OP bone tissue. Adiponectin expression was lower in OP than in OA and a trend was seen for controls. These results suggest OP bone has lower TG metabolism than OA and normal bone. In OP bone, lower osteoblastogenesis and higher osteoclast formation were observed and correlation analysis suggests adiponectin, LPL and HSL are associated with higher osteoblastogenesis and lower osteoclastogenesis. This study gives insights into TG metabolism in the human bone microenvironment. We conclude that OP bone tissue exhibits lower osteoblastogenesis, higher osteoclastogenesis and lower TG metabolism compared to OA or healthy controls.

Several studies have shown that in contrast to osteoporosis (OP), osteoarthritis (OA) is characterized by high bone mineral density (BMD). Bone strength not only depends on mineral content as determined by dual X-ray absorptiometry (DXA), but also on bone microarchitecture. We studied intertrochanteric bone from normal controls and OA and OP patients by bone histomorphometry (BHM) and microcomputed tomography (mCT) as well as DXA in order to first, test the differences between OA and OP comparing both groups to healthy controls, second, to assess variations between three different skeletal sites in controls and third, to determine the level of agreement between mCT, BHM, and DXA. Analysis was performed on 115 samples from OA and OP patients, and controls. We found significant differences between OA and OP samples in structural parameters and in the osteoid fraction (p < 0.05). The majority of the intra-skeletal differences were shown between lumbar spine and femoral head samples (p < 0.05). Significant agreements were found between mCT and BHM and DXA (r ¼ 0.32-0.45, p < 0.05). Our findings suggest differences in intertrochanteric bone between OA and OP, the age-related intra-skeletal variations and a correlation between microscopic and macroscopic bone evaluation methods. Keywords: osteoarthritis; osteoporosis; controls; mCT; histomorphometry Osteoarthritis (OA) and osteoporosis (OP) are two common age-related diseases that cause disability in elderly people either by fractures in OP, or by crippling due to pain and stiffness in OA. 1 OP is a skeletal disease recognized by low bone mineral density (BMD) and deterioration of bone microarchitecture leading to a higher fracture risk. 2 The main characteristic of OA is degeneration of the articular cartilage, however, there are recent suggestions on OA being more than just disease of cartilage with a metabolic component as well. 3 BMD at various sites in skeleton, including sites distal to the affected joint, was reported to be higher and bone metabolism was lower in patients with OA compared to those with OP. [4][5][6] Mechanical properties such as apparent density and mechanical stiffness were also increased in OA and decreased in OP compared to normal femoral neck bone. 7 As OA patients who do develop OP fracture were shown to be older than those patients suffering from OP only, OA has been suggested to protect against fracture. [8][9][10][11][12] However, there is also evidence on similar or even higher risk of fractures among OA patients. 13,14 Differences at microstructural level were observed as well. The alterations of the subchondral bone such as increased thickness, number of collagen fibers, lacunae, and osteoblasts have a well-established role in the pathogenesis of OA. [15][16][17] Bone histomorphometry (BHM) has shown increased or similar structural indices in intertrochanteric bone in OA compared to controls. 18,19 Dual energy X-ray absorptiometry (DXA), currently the most important diagnostic tool for screening for OP, 2 can provide data o...

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