Bone Mineral Density in the Proximal Femur and Contralateral Knee After Total Knee Arthroplasty

Osteoarthrosis (OA) is often associated with pain and disability, which are relieved after total knee arthroplasty (TKA), but the nature of bone changes associated with OA is controversial. We examined preoperative hip and contralateral knee bone mineral density (BMD) in patients requiring TKA and monitored the BMD changes postoperatively. Sixty-nine patients, scheduled to have TKA for osteoarthrotic knees, had both hips and contralateral knee BMD measured by dual-energy X-ray absorptiometry (DXA) at the time of operation (baseline) and at 1 yr after operation. X-rays of the knee joints were also taken to evaluate the severity of OA. Preoperatively, 27% and 38% of the patients had total hip BMD Z-score more than 1 SD in the operated side and contralateral hips, respectively. In all regions of interest (ROI), the mean baseline BMD of the affected side proximal femur was significantly lower than that of the contralateral side (p < 0.0005-0.019). The severity of OA was not associated with BMD. During 1-yr follow-up, the postoperative knee status and the physical activity of the patients (AKS score) improved. However, neither the hip nor the nonoperated knee BMDs increased. Knee OA is associated with significantly lower BMD values in the affected side compared with the contralateral hip, and these levels remained similar or decreased during a 1-yr follow-up. We conclude that improved mobility after TKA does not improve the effects of preoperative disuse-associated bone loss in the short term.     

The effect of intravenous dopamine and dobutamine on blood circulation during a microvascular TRAM flap operation

A study was conducted to assess the effect of intraoperatively administered inotropic agents on blood flow in the recipient and donor vessels, during breast reconstruction with a muscle sparing free TRAM flap. Twenty-one consecutive patients were randomized into 3 groups receiving either dopamine, dobutamine, or placebo. When the flap and all vessels had been fully dissected but not yet divided, the study drug was administered intravenously for 15 minutes. Hemodynamic parameters and transit-time flow of the thoracodorsal and inferior epigastric arteries were monitored.Both dobutamine and dopamine infusions resulted in significant raises in cardiac output and mean arterial pressure. However, while dobutamine resulted in a higher cardiac output (P = 0.001) and a decrease in systemic vascular resistance (P = 0.028), the increase in mean arterial pressure was greater with dopamine (P = 0.002). Only the dobutamine group showed increased blood flow, in both the thoracodorsal (P = 0.043) and the inferior epigastric (P = 0.043) arteries.If vasoactive agents are needed during microvascular anesthesia, dobutamine seems to be more advantageous than dopamine.     

Periprosthetic tibial bone mineral density changes after total knee arthroplasty: one-year follow-up study of 69 patients

BACKGROUND: The critical structure supporting the prosthetic components in total knee arthroplasty (TKA) is tibial trabecular bone. The quality of tibial bone can be evaluated by bone mineral density (BMD) measurements. PATIENTS AND METHODS: We prospectively measured changes in BMD in the proximal tibia after cemented TKA in osteoarthrotic knees. 69 patients were scanned by dual-energy X-ray absorptiometry (DXA) within a week after surgery, and after 3, 6 and 12 months. RESULTS: At baseline, the medial region of interest (ROI) BMD was higher in the varus knees than in the valgus aligned knees (p=0.02). The medial metaphyseal ROI showed a decrease in BMD during the follow-up in preoperatively varus knee joints (p<0.001). In preoperatively valgus knees, there was a slight increase in medial compartment BMD which was not significant (p=0.2). Alignment correction in both groups showed bone remodeling giving similar medial and lateral BMD values, suggesting that the bone became equally strong in both compartments of the metaphysis. There was no association between increasing American Knee Society (AKS) scores and bone remodeling. INTERPRETATION: We suggest that this remodeling is caused by postoperative changes in tibial loading. Our results support the clinical importance of recreating proper valgus alignment of the knee joint in the TKA operation, thus possibly providing better conditions for longevity of the tibial component.     

Increased Blood Acetate: A New Laboratory Marker of Alcoholism and Heavy Drinking

Blood acetate concentration of 51 intoxicated patients was measured and compared to conventional laboratory markers of chronic alcoholism. Mean blood acetate concentration of 23 chronic alcoholics and 17 heavy drinkers was significantly (p less than 0.0005) higher than that of 53 nonalcoholic volunteers or 11 occasional drinkers. Blood acetate level was completely independent of blood ethanol concentration ranging from 0.20 to 2.90 promille. Blood acetate was elevated in 65% of both chronic alcoholics and heavy drinkers. Gammaglutamyltransferase was abnormal only in 35%, aspartate aminotransferase in 21% and mean corpuscular volume in 12% of heavy drinkers. Combination (acetate + gammaglutamyltransferase) correctly detected 87% of alcoholics and 71% of heavy drinkers. During ethanol oxidation the upper normal limit of blood acetate is 0.75 mM. The specificity of increased blood acetate is as high as 92%. Increased blood acetate is indicative for metabolic tolerance to alcohol and it may be so far the most sensitive and specific laboratory marker of chronic alcoholism and heavy drinking.     

Elbow synovectomy on patients with juvenile rheumatoid arthritis

Twenty-four primary elbow synovectomies were done between 1991 and 1998 at the authors' institution on 19 patients (15 females, four males) with juvenile rheumatoid arthritis. Five bilateral and 14 unilateral procedures were done. The mean age of the patients was 29 years (range, 11-64 years) at the time of surgery and the mean disease duration was 19 years (range, 2-51 years). Preoperatively radiographic destruction of Larsen Grade 1 was detected in 21% of elbows, Grade 2 in 54%, and Grade 3 in 4%. In 21% of elbows no radiographic destruction was present (Grade 0). The cumulative survival rate of elbow synovectomy was 84% (95% confidence interval, 68-98) at 5 years. Four resynovectomies and two elbow replacement arthroplasties were done during the followup period. Complete pain relief was documented in 44% of patients and subjective outcome was excellent or good in 72% of patients. No significant improvement was observed in functional ability or range of motion in extension and flexion or pronation and supination. The results of the current study (mean followup, 5 years; range, 2-9 years) are slightly worse compared with the short-term results of elbow synovectomy in patients with adult-onset rheumatoid arthritis.     

A role for decorin in cutaneous wound healing and angiogenesis

Decorin is known to influence tissue tensile strength and cellular phenotype. Therefore, decorin is likely to have an impact on tissue repair, including cutaneous wound healing. In this study, cutaneous healing of both excisional and incisional full‐thickness dermal wounds was studied in decorin‐deficient (Dcn^?/?) animals. A statistically significant delay in excisional wound healing in the Dcn^?/? mice occurred at 4 and 10 days postwounding and, in incisional wounds at 4, 10, and 18 days when compared with wild‐type (Dcn^?/?) controls. Fibrovascular invasion into polyvinylalcohol sponges was significantly increased by day 18 in Dcn^?/? mice relative to Dcn^+/+ mice. The 18‐day sponge implants in the Dcn^?/? mice showed a marked accumulation of biglycan when compared with the corresponding implants in Dcn^+/+ mice. Thus, regulated production of decorin may serve as an excellent therapeutic approach for modifying impaired wound healing and harmful foreign body reactions.     

Liver and serum expression of matrix metalloproteinases in asymptomatic pediatric liver transplant recipients

We related hepatic gene and serum expression of matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) to liver histology in pediatric LT recipients. Liver biopsies and serum samples were obtained from 52 patients 10.6 years post‐LT and age‐matched controls for analyses of MMPs and TIMPs. Patients with fibrosis had significantly higher hepatic gene expression of MMP‐2, MMP‐9, MMP‐14, TIMP‐1, and TIMP‐2 than patients without. Expression of these genes correlated with graft Metavir fibrosis stage (r = 0.494–0.684, P ≤ 0.006 for all). Gene expression of MMP‐1, MMP‐3, MMP‐8, TIMP‐3, and TIMP‐4 was undetectable in both patients and controls. Portal inflammation and cytokeratin 7 correlated positively with gene expression of TIMP‐1. Gene expression of MMP‐2, MMP‐9, and TIMP‐2 correlated negatively with the time of low‐dose cortisone usage (r = ?0.448 to ?0.422, P < 0.05 for all). Serum concentrations of MMP‐8 and TIMP‐1 were significantly increased and MMP‐9 decreased among patients compared with controls, but no correlations to graft histology or gene expression were observed. Hepatic gene expression of certain MMPs and TIMPs is increased in stable pediatric LT recipients displaying graft fibrosis, but this did not reflect to their serum concentrations. Increased hepatic gene expression of TIMP‐1 correlated with graft fibrosis stage, inflammation, and chronic cholestasis.     

Abnormally High and Heterogeneous Bone Matrix Mineralization After Childhood Solid Organ Transplantation: A Complex Pathology of Low Bone Turnover and Local Defects in Mineralization

Chronic renal, liver, and heart failure in children associates with multiple skeletal complications. Increased fracture incidence often persists after transplantation and could be related to alterations in bone material properties. In the present cohort study we evaluated bone mineralization density distribution (BMDD) by quantitative backscattered electron imaging (qBEI) in 23 pediatric solid organ allograft recipients with suspected osteoporosis. We measured BMDD in the entire cross‐sectional area of transiliac bone biopsies obtained from kidney (n = 9), liver (n = 9), and heart (n = 5) transplant recipients (aged 7.6 to 19.7 years; 6.0 ± 5.6 years posttransplantation, patients with a history of clinical fractures: n = 14). The BMDD findings were compared with age‐appropriate references and with a previously presented cohort of children with chronic kidney disease on dialysis (CKD5D, n = 18). Furthermore, we related the BMDD parameters with patients’ clinical and bone histomorphometric outcomes. Compared to healthy children, qBEI results for cancellous and cortical bone in transplant recipients revealed an increase in the most frequently occurring calcium concentration (+2.9%, p = 0.001; +3.5%, p = 0.014), in the portion of fully mineralized bone (fivefold; 10‐fold, both p < 0.0001) and in heterogeneity of mineralization (+26,5% and +27.8%, both p < 0.0001), respectively. Moreover, the BMDD parameters were nonsignificantly distinct from CKD5D cohort except that the heterogeneity in mineralization was higher posttransplantation. There was a strong inverse correlation between the average calcium content of the bone matrix and patients’ biochemical ALP levels, histomorphometric indices of bone formation and resorption. The abnormally high bone matrix mineralization in transplant recipients, consistent with serum and histomorphometric outcomes, suggests a history of low bone turnover with accumulation of fully mineralized bone packets. Additionally, the increased heterogeneity of mineralization suggests local alterations in mineralization kinetics, which may be linked to dysfunctional osteocytes that were recently shown to accumulate within the bone matrix during organ failure and concomitant glucocorticoid and immunosuppressive medication. © 2017 American Society for Bone and Mineral Research.     

Localization of small leucine‐rich proteoglycans and transforming growth factor‐β in human oral mucosal wound healing

Wound healing in oral mucosa is fast and results in little scar formation as compared with skin. The biological mechanisms underlying this property are poorly understood but may provide valuable information about the factors that promote wound regeneration. Small leucine‐rich proteoglycans (SLRPs) decorin, biglycan, fibromodulin and lumican are extracellular matrix molecules that regulate collagen fibrillogenesis, inhibit transforming growth factor‐β (TGF‐β) activity and reduce scarring. In the present study, we analyzed accumulation of SLRPs and TGF‐β during non‐scarring human oral mucosal wound healing. Biopsies were collected from healthy volunteers from unwounded tissue and from standardized experimental wounds 3–60 days postwounding. Localization of SLRPs, TGF‐β1 and TGF‐β3 was analyzed by immunohistochemical staining and quantitated by image analysis. Double immunostaining was used to study localization of SLRPs or active TGF‐β in distinct cells. Decorin, biglycan, fibromodulin, and TGF‐β isoforms showed significantly increased accumulation in the wound extracellular matrix and distinct wound cells while the abundance of lumican in the extracellular matrix was strongly reduced during wound healing. Localization and abundance of fibromodulin, lumican, and TGF‐β isoforms was also spatiotemporally regulated in the wound epithelium. The findings suggest that SLRPs regulate wound reepithelialization and connective tissue regeneration during oral mucosal wound healing.