Hip fractures are a significant cause of mortality and morbidity in the elderly. Malnutrition is a major element of this but no consensus exists as to the detection or management of this condition. Reported incidence in elderly hip fracture patients varies widely between 9.0% and 88.6%. The aim of this study was to evaluate the nutritional status of 415 patients with operatively managed hip fractures and determine the prognostic relevance of admission serum albumin and total lymphocyte count (TLC) assays. Protein-energy malnutrition (PEM) was defined as serum albumin < 3.5g/dl and a TLC < 1,500 cells/mm3. Delay to operation, duration of in-patient stay, re-admission (< 3 months) and in-patient, 3- and 12-month mortality were assessed as outcome variables. Survival data was available for 377 patients at 12 months. Of 377 patients, 53% (n=200) had both a serum albumin and TLC levels taken at admission, while 47% (n=177) had not. The incidence of PEM was 51%. Inhospital mortality for PEM patients was 9.8%, compared with 0% for patients with normal values of both laboratory parameters. Older patients were more likely to have lower albumin (p=0.017) and TLC (p=0.023). Nursing home patients were also more likely to have lower albumin (p=0.033). Multivariate analysis revealed a significant difference in 12-month mortality, with patients who had both a low albumin and a low TLC 4.6 times (95% CI: 1.0–21.3) more likely to die within 12 months postoperatively than patients who had normal values of both laboratory parameters. This was significant after adjusting for age, gender and domicile (p=0.049). Serum albumin and TLC in combination are accurate predictors of 12-month mortality in hip fracture patients. These results highlight the relevance of assessing the nutritional status of patients with hip fractures at the time of admission and emphasises the relationship between nutrition and outcome

Malnutrition is a potentially modifiable risk factor that may contribute to complications following geriatric hip fracture surgery. The purpose of this study was to investigate the association between preoperative hypoalbuminemia, a marker for malnutrition, and complications during the thirty days following surgery for geriatric hip fracture. The American College of Surgeons National Surgical Quality Improvement Program was used to conduct a retrospective cohort study of geriatric patients (>65 years) undergoing surgery for hip fracture. Patients without preoperative serum albumin concentration were excluded. Outcomes were compared between patients with and without hypoalbuminemia (defined as serum albumin concentration <3.5g/dL). All comparisons were adjusted for baseline differences between populations. 17,651 Patients were identified. Of these, 8,272 (46.9%) underwent hemiarthroplasty, 759 (4.3%) total joint arthroplasty, 324 (1.9%) percutaneous fixation, 2,445 (13.9%) plate/screw fixation, and 5,833 (33.1%) intramedullary fixation. The prevalence of hypoalbuminemia was 45.9% (Figure 1). The risk for death was strongly associated with serum albumin concentration, with a linear increase in risk observed as albumin fell below 3.5 g/dL (p<0.001; Figure 2). Following adjustment for all demographic, comorbidity, and procedural characteristics, patients with hypoalbuminemia had higher rates of death (9.94% versus 5.53%, adjusted relative risk [RR]=1.54, p<0.001), pneumonia (5.30% versus 3.77%, adjusted RR=1.20, p=0.012), sepsis (1.19% versus 0.53%, adjusted RR=1.90, p<0.001), and hospital readmission (10.91% versus 9.03%, adjusted RR=1.11, p<0.036; Table 1). The present study suggests that hypoalbuminemia is a powerful independent risk factor for death following surgery for geriatric hip fracture. This association persists over-and-above any associations of death with age, sex, body mass index, and comorbidities. Based on these data, we propose that the nutritional status of hip fracture patients should receive greater attention, and that randomized trials testing for efficacy of aggressive postoperative nutritional interventions may be warranted. For any figures or tables, please contact the authors directly by clicking on ‘Info & Metrics’ above to access author contact details

Background: Protein energy malnutrition (PEM) is an accepted predictor of poor outcome in hip fracture patients. There is no universally accepted definition of PEM. Admission screening for PEM is not routinely performed for hip fracture patients. The reported incidence in elderly hip fracture patients varies widely between 9.0% and 88.6%. Aims: To determine the prognostic relevance of admission serum albumin and total lymphocyte count (TLC), as clinical markers of PEM and predictors of outcome for hip fracture patients. Methods: Retrospective review of 415 patients with operatively managed hip fracture. Protein-energy malnutrition was defined as albumin < 3.5g/dl and TLC < 1,500cells/mm3. Delay to operation, duration of in-patient stay, readmission (< 3 months) and in-patient, 3- and 12-month mortality were assessed as outcome variables. Results: Survival data was available for 377 patients at 12 months. Of 377 patients, 53% (n=200) had both a serum albumin and TLC levels taken at admission (study), while 47% (n=177) had not (control). Incidence of PEM was 51%. Older patients were more likely to have lower albumin (p=0.03) and TLC (p=0.012). Nursing home patients were also more likely to have lower albumin (p=0.049). In-hospital mortality for PEM patients was 9.8%, compared with 0% for patients with normal values of both laboratory parameters. Patients with PEM had a higher 12-month mortality compared to patients who had normal values of both laboratory parameters (Odds Ratio=4.52; p=0.049). Conclusion: Serum albumin and TLC in combination are accurate predictors of 12-month mortality in hip fracture patients. These results underscore the clinical relevance of assessing the nutritional status of patients with hip fractures at the time of admission and emphasises the relationship between nutrition and outcome in these patients

Miniscrew implants (MSIs) are widely used to provide absolute anchorage for the orthodontic treatment. However, the application of MSIs is limited by the relatively high failure rate (22.86%). In this study, we wished to investigate the effects of amorphous and crystalline biomimetic calcium phosphate coating on the surfaces of MSIs with or without the incorporated BSA for the osteointegration process with an aim to facilitate the early loading of MSIs. Amorphous and crystalline coatings were prepared on titanium mini-pin implants. Characterizations of coatings were examined by Scanning electron microscopy (SEM), Confocal laser-scanning dual-channel-fluorescence microscopy (CLSM) and Fourier-transform infrared spectroscopy (FTIR). The loading and release kinetics of bovine serum albumin (BSA) were evaluated by Enzyme linked immunosorbent assay (ELISA). Activity of alkaline phosphate (ALP) was measured by using the primary osteoblasts. In vivo, a model of metaphyseal tibial implantation in rats was used (n=6 rats per group). We had 6 different groups: no coating no BSA, no coating but with surface adsorption of BSA and incorporation of BSA in the biomimetic coating in the amorphous and crystalline coatings. Time points were 3 days, 1, 2 and 4 weeks. Histological and histomorphometric analysis were performed and the bone to implant contact (BIC) of each group was compared. In vitro, the incorporation of BSA changed the crystalline coating from sharp plates into curly plates, and the crystalline coating showed slow-release profile. The incorporation of BSA in crystalline coating significantly decreased the activity of ALP in vitro. In vivo study, the earliest significant increase of BIC appeared in crystalline coating group at one week. The crystalline coating can serve as a carrier and slow release system for the bioactive agent and accelerate osteoconductivity at early stage in vivo. The presence of BSA is not favorable for the early establishment of osteointegration

Background: Protein energy malnutrition (PEM) is an accepted predictor of poor outcome in hip fracture patients. There is no universally accepted definition of PEM. Admission screening for PEM is not routinely performed for hip fracture patients. The reported incidence in elderly hip fracture patients varies widely between 9.0% and 88.6%. Aims: To determine the prognostic relevance of admission serum albumin and total lymphocyte count (TLC), as clinical markers of PEM and predictors of outcome for hip fracture patients. Methods: Retrospective review of 415 patients with operatively managed hip fracture. Protein-energy malnutrition was defined as albumin < 3.5g/dl and TLC < 1,500 cells/ mm3. Delay to operation, duration of in-patient stay, readmission (< 3 months) and in-patient, 3- and 12-month mortality were assessed as outcome variables. Results: Survival data was available for 377 patients at 12 months. Of 377 patients, 53% (n=200) had both a serum albumin and TLC levels taken at admission (study), while 47% (n=177) had not (control). Incidence of PEM was 51%. Older patients were more likely to have lower albumin (p=0.03) and TLC (p=0.012). Nursing home patients were also more likely to have lower albumin (p=0.049). In-hospital mortality for PEM patients was 9.8%, compared with 0% for patients with normal values of both laboratory parameters. Patients with PEM had a higher 12-month mortality compared to patients who had normal values of both laboratory parameters (Odds Ratio=4.52; p=0.049). Conclusion: Serum albumin and TLC in combination are accurate predictors of 12-month mortality in hip fracture patients. These results underscore the clinical relevance of assessing the nutritional status of patients with hip fractures at the time of admission and emphasises the relationship between nutrition and outcome in these patients

Aims

Serum inflammatory parameters are widely used to aid in diagnosing a periprosthetic joint infection (PJI). Due to their limited performances in the literature, novel and more accurate biomarkers are needed. Serum albumin-to-globulin ratio (AGR) and serum CRP-to-albumin ratio (CAR) have previously been proposed as potential new parameters, but results were mixed. The aim of this study was to assess the diagnostic accuracy of AGR and CAR in diagnosing PJI and to compare them to the established and widely used marker CRP.

Sarcopenia has been observed to be a predictor of mortality in international studies of patients with metastatic disease of the spine. This study aimed to validate sarcopenia as a prognostic tool in a New Zealand setting. A secondary aim of this study was to assess the intra-observer reliability of measurements of psoas and vertebral body cross sectional areas on computed tomography imaging. A cohort of patients who had presented to Waikato Hospital with secondary neoplasia in the spinal column from 2014 to 2018 was selected. Cross sectional psoas and vertebral body areas were measured at the mid-pedicle L3 level, followed by calculation of the psoas to vertebral body cross sectional area ratio. Psoas to vertebral body cross sectional area ratio was compared with survivorship. The strength of the correlation between sarcopenia and survivorship was compared with the correlation between serum albumin and survivorship, as well as the correlation between the Metastatic Spine Risk Index (MSRI) and survivorship. A total of 110 patients who received operative (34) and non-operative (76) were included. The results demonstrate that psoas to vertebral body cross sectional area ratio is not statistically significantly correlated with survivorship (p=0.53). Serum albumin is significantly correlated with survivorship (p<0.0001), as was the MSRI. There is good intra-observer and inter-observer reliability for measurements of psoas to vertebral body cross sectional area. This study failed to demonstrate the utility for the psoas to vertebral body cross sectional area ratio that other studies have demonstrated in estimating survivorship. Serum albumin levels remain a useful prognostic indicator in patients with secondary tumours in the vertebral column

Malnutrition is an important consideration during the perioperative period and albumin is the most common laboratory surrogate for nutritional status. The purpose of this study is to identify if preoperative serum albumin measurements are predictive of infection following arthroscopic procedures. Patients undergoing knee, shoulder or hip arthroscopy between 2006–2016 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients with an arthroscopic current procedural terminology code and a preoperative serum albumin measurement were included. Patients with a history of prior infection, including a non-clean wound class, pre-existing wound infection or systemic sepsis were excluded. Independent t-tests where used to compare albumin values in patients with and without the occurrence of a postoperative infection. Pre-operative albumin levels were subsequently evaluated as predictors of infection with logistic regression models. There were 31,906 patients who met the inclusion criteria. The average age was 55.7 years (standard deviation (SD) 14.62) and average BMI was 31.7 (SD 7.21). The most prevalent comorbidities were hypertension (49.2%), diabetes (18.4%) and smoking history (16.9%). The average preoperative albumin was 4.18 (SD 0.42). There were 45 cases of superficial infection (0.14%), 10 cases of wound dehiscence (0.03%), 17 cases of deep infection (0.05%), 27 cases of septic arthritis or other organ space infection (0.08%) and 95 cases of any infection (0.30%). The preoperative albumin levels for patients who developed septic arthritis (mean difference (MD) 0.20, 95% CI, 0.038, 0.35, P = 0.015) or any infection (MD 0.14, 95% CI 0.05, 0.22, P = 0.002) were significantly lower than the normal population. Additionally, disseminated cancer, Hispanic race, inpatient status and smoking history were significant independent risk factors for infection, while female sex and increasing albumin were protective towards developing any infection. Rates of all infections were found to increase exponentially with decreasing albumin. The relative risk of infection with an albumin of 2 was 3.46 (95% CI, 2.74–4.38) when compared to a normal albumin of 4. For each albumin increase of 0.69, the odds of developing any infection decreases by a factor of 0.52. This study suggests that preoperative serum albumin is an independent predictor of septic arthritis and all infection following elective arthroscopic procedures. Although the effect of albumin on infection is modest, malnutrition may represent a modifiable risk factor with regard to preventing infection following arthroscopy

Introduction: Wound discharge is a well-known and troubling problem after orthopedic surgical procedures. Diagnosis of its etiology is critical for proper management. One of the most important etiologies of wound discharge is surgical site infection. Hypoalbuminemia is a known problem after surgeries of spine and in burn victims and its association with some complications such as impaired wound or bone healing increased surgical failure rates and increased rate of infection in these patients is considered by some authors. In this study we considere hypoalbuminemia as a cause of culture-negative, clear (transudative) surgical wound discharge after orthopedic procedures and discuss the effect of its management on cessation of discharge. Method: In a prospective cross sectional study during one year, we evaluated all patients with ongoing orthopedic surgical wound discharge except for discharges after spinal surgeries and those for the treatment of suspected musculoskeletal infections. The patients with culture negative, clear (transudative) surgical wound discharge were evaluated for the presence of hypoalbuminemia (serum albumin< 3.5 g/dl) as a cause of the problem. The outcome of the correction of hypoalbuminemia on cessation of the discharge and occurrence of any complications regarding this treatment were assessed carefully. Results: Among 2573 orthopedic surgical procedures, we found 11 culture negative clear (transudative) wound discharges (incidence: 0.4%). There were 7 male and 4 females with mean age of 59 years (age range between 34 and 83 years). The mean of serum albumin level in these patients was 2.8 g/dl (range between 2.1 g/dl to 3.2 g/dl). The discharge was started 3 to 8 days (mean: 4.8) after surgery, continued for 2 to 6 days (mean: 3.7) after initiation of albumin administration, and has been stopped since one day before to one day after normalization of the serum albumin level. Interestingly, all of the patients had a major orthopedic surgical procedure on the proximal parts of their lower limbs. Blood transfusion was done in 10 cases and there was a significant association between serum albumin level and ICU admission (p Value < 0.05). During the study no complication directly related to albumin administration was detected. Conclusions: hypoalbuminemia should be considered as the cause of sterile and clear wound discharges especially after orthopedic surgical procedures on proximal parts of lower limb. The management of hypoalbuminemia could be related to cessation of the discharge

Objectives. The goal of this study was to determine whether intra-articular administration of the potentially anti-fibrotic agent decorin influences the expression of genes involved in the fibrotic cascade, and ultimately leads to less contracture, in an animal model. Methods. A total of 18 rabbits underwent an operation on their right knees to form contractures. Six limbs in group 1 received four intra-articular injections of decorin; six limbs in group 2 received four intra-articular injections of bovine serum albumin (BSA) over eight days; six limbs in group 3 received no injections. The contracted limbs of rabbits in group 1 were biomechanically and genetically compared with the contracted limbs of rabbits in groups 2 and 3, with the use of a calibrated joint measuring device and custom microarray, respectively. Results. There was no statistical difference in the flexion contracture angles between those limbs that received intra-articular decorin versus those that received intra-articular BSA (66° vs 69°; p = 0.41). Likewise, there was no statistical difference between those limbs that received intra-articular decorin versus those who had no injection (66° vs 72°; p = 0.27). When compared with BSA, decorin led to a statistically significant increase in the mRNA expression of 12 genes (p < 0.01). In addition, there was a statistical change in the mRNA expression of three genes, when compared with those without injection. . Conclusions. In this model, when administered intra-articularly at eight weeks, 2 mg of decorin had no significant effect on joint contractures. However, our genetic analysis revealed a significant alteration in several fibrotic genes. Cite this article: Bone Joint Res 2014;3:82–8

Summary. Based upon genetic analysis, decorin is an exciting pharmacologic agent of potential anti-fibrogenic effect on arthrofibrosis in our animal model. Introduction. While the pathophysiology of arthrofibrosis is not fully understood, some anti-fibrotic molecules such as decorin could potentially be used for the prevention or treatment of joint stiffness. The goal of this study was to determine whether intra-articular administration of decorin influences the expression of genes involved in the fibrotic cascade ultimately leading to less contracture in an animal model. Material and Methods. Eighteen rabbits had their right knees operated on to form contractures. The left knees served as controls. The 6 right limbs in the experimental group (Group 1) received four 500 ug/ml intra-articular injections of decorin over 8 days starting at 8 week, for a total of 2 mg. The 6 right limbs in the first control group (Group 2) received four intra-articular injections of bovine serum albumin (BSA) over 8 days starting at 8 weeks as well. The 6 six right limbs in the second control group (Group 3) received no injections. The contracted limbs of rabbits in Group 1 were biomechanically and genetically compared to the contracted limbs of rabbits in Groups 2 and 3 with the use of a calibrated joint measuring device and custom microarray, respectively. Results. There was no statistical difference in the flexion contracture angles between those right limbs that received intra-articular decorin versus those that received intra-articular BSA (66° vs. 69°; p = 0.41). Likewise, there was no statistical difference between those right limbs that received intra-articular decorin as opposed to those who had no injection (66° vs. 72°; p = 0.27). The lack of significance remained when the control left limbs were taken into account (p > 0.40). When compared to bovine serum albumin (BSA), decorin led to a statistically significant increase in the mRNA expression of 5 genes: substance P, neuropeptide γ, and neurokinin A, cyclin E2, and MMP-9 (p < 0.001). In addition, there was a statistically significant decrease in fibroblast growth factor receptor-2 (FGFR-2), rho-associated coiled-coil containing protein kinase-1 (ROCK-1), and vascular cell adhesion molecule-1 (VCAM-1) genes when intra-articular decorin was compared to no injection (p < 0.001). Conclusions. In this model, when administered intra-articularly at 8 weeks, 2 mg of decorin had no significant effect on joint contractures. However, our genetic analysis revealed a significant alteration in the expression of several fibrotic genes. Further studies investigating the route of administration, dosing, frequency, and timing are required before definitive conclusions may be drawn on the effects of decorin on joint contractures

Aim. To validate the implementation of relatively inexpensive and reliable laboratory tests in everyday clinical practice for the early recognition of malnutrition in patients with a hip fracture. Correlation of malnutrition with clinical parameters. Method. Retrospective study including all elderly patients operated for a hip fracture during a five year period. Patients were evaluated according to two laboratory parameters: serum albumin and total lymphocyte count. Both parameters are established and widely used nutritional indexes. Based on the results, patients were divided into four groups: Patients in group A had both parameters within normal limits. Group B had a low total lymphocyte count and a normal albumin level. Reversibly, patients in group C had a low albumin level and a normal total lymphocyte count. In group D both values were abnormal. The groups were compared according to three clinical parameters: waiting time to operation, duration of hospital stay and one year postoperative mortality. Results. Three hundred and twenty nine patients were included in the study. Statistically important differences were found for all three clinical parameters between malnourished patients (group D) and those with normal values (group A). Conclusion. Serum albumin levels and a total lymphocyte count are reliable nutritional indexes in patients with a hip fracture. Their implementation in clinical practice can contribute to the early recognition and appropriate treatment of patients with a worse prognosis

Introduction. Hypoalbuminemia has previously been identified as an independent predictor of postoperative complications following total knee arthroplasty (TKA). Given the morbidity and financial burden associated with TKA complications, significant effort has gone into identifying patients at increased risk for perioperative complications. The American Society of Anesthesiologists (ASA) physical status score has been utilized for risk stratification of surgical patients for many years and is a measure of overall health. However, it is unclear how measures like albumin compare to the prognostic ability of this type of global health measure. This study aims to elucidate the utility of preoperative albumin compared with that of the ASA score in predicting complications following TKA. Methods. Patients undergoing TKA between 2005 and 2015 were identified using the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database. Patients were stratified based on preoperative hypoalbuminemia (<3.5 g/dL) and ASA score (≤ 2 vs. > 2). Multivariable regression analysis adjusted for age, sex, BMI, and smoking status was utilized to determine predictive potential of hypoalbuminemia and ASA score on each postoperative complication. Results. Of the 79,661 patients included in the cohort, 4.3% had preoperative hypoalbuminemia. Univariate regression analysis found significant predictive abilities of both serum albumin and ASA score on numerous postoperative complications, such as superficial infection, deep infection, MI, pneumonia, renal insufficiency, reintubation, transfusion, readmission, reoperation, and death. Interestingly, multivariable regression analysis demonstrated that hypoalbuminemia more robustly predicted postoperative deep infection than ASA. Discussion and Conclusion. Hypoalbuminemia and ASA each individually predict numerous postoperative complications following TKA. However, this study suggests that while ASA score more accurately predicts post-operative medical complications, hypoalbuminemia may be a more accurate predictor of periprosthetic infection following TKA. Ultimately, preoperative albumin should be incorporated in the pre-operative work-up routine to stratify patient risk, especially regarding postoperative infection

Obtaining primary wound healing in total joint arthroplasty (TJA) is essential to a good result. Wound healing disturbances (WHD) can occur and the consequences can be devastating to the patient and to the surgeon. Determination of the host healing capacity can be useful in predicting complications. Cierney and Mader classified patients as Type A: no healing compromises and Type B: systemic or local healing compromise factors present. Local factors include traumatic arthritis with multiple previous incisions, extensive scarring, lymphodema, poor vascular perfusion, and excessive local adipose deposition. Systemic compromising factors include diabetes, rheumatic diseases, renal or liver disease, immunocompromise, steroids, smoking, and poor nutrition. Low serum albumin, total lymphocyte count, and low transferrin increase WHD. In high risk situations the surgeon should encourage positive patient choices such as smoking cessation and nutritional supplementation to modify healing responses. Use of tourniquet in obese patients also increases WHD. Careful planning of incisions, particularly in patients with scarring or multiple previous operations, is productive. Around the knee the vascular viability is better in the medial flap. Thusly, use the most lateral previous incision, do minimal undermining, and handle tissue meticulously. We do all potentially complicated TKA's without tourniquet to enhance blood flow and tissue viability. The use of perioperative anticoagulation will increase wound problems. If wound drainage or healing problems do occur, immediate action is required. Deep sepsis can be ruled out with a joint aspiration and cell count (less than 2500), differential (less than 60% polys), and negative culture and sensitivity. All hematomas should be evacuated and necrosis or dehiscence should be managed by debridement to obtain a live wound

Aims: To elicit the predisposing factors responsible for early death in the aged population with hip fracture. Methods: In this perspective study we dealed with 65 patients over 65 years old (51 women) with mean age 80.1 years old (65 – 104) who suffered a hip fracture (34 trochanteric and 31 subcapital). We studied age, sex, ASA score, delay for surgery and mobility preoperatively, blood loss and operative time interoperatively and postoperative delirium and fixation failure. Haemoglobin, WBC, serum albumin and Mini Mental Test were recorded both pre and postoperatively. The place of the accident was also recorded. The above parameters were compared for survivors and non-survivors patients. Results: 11 patients died during the first 6 months with a mortality rate 16.9%. In all other parameters we detected no significant differences between groups. Conclusions: The failure pattern (deaths) after a hip fracture during the first 6 months postoperatively included female of advanced age, with dementia and medical problems (ASA), who developed delirium postoperatively and had diminished preoperatively mobility

Purpose. A major drawback of current cartilage and intervertebral disc (IVD) tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients express high levels of type X collagen. Type X collagen is a marker of late stage chondrocyte hypertrophy, linked with endochondral ossification, which precedes bone formation. However, it has been shown that a novel plasma-polymer, called nitrogen-rich plasma-polymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs. The aim of this study was to determine if the decreased expression of type X collagen, induced by the PPE:N surfaces is maintained when MSCs are removed from the surface and transferred to pellet cultures in the presence of serum and growth factor free chondrogenic media. Method. Human MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Cells were expanded for 2–3 passages and then cultured on polystyrene dishes and on two different PPE:N surfaces: high (H) and low (L) pressure deposition. Cells were transferred for 7 additional days in chondrogenic serum free media (DMEM high glucose supplemented with 2 mM L-glutamine, 20 mM HEPES, 45 mM NaHCO3, 100 U/ml penicillin, 100 ug/ml streptomycin, 1 mg/ml bovine serum albumin, 5 ug/ml insulin, 50 ug/ml ascorbic acid, 5 ng/ml sodium selenite, 5 ug/ml transferrin) in pellet culture or on PS cell culture dishes. RNA was extracted using a standard TRIzol protocol. RT-PCR was realized using Superscript II (RT) and Taq polymerase (PCR) with primers specific for type I and X collagen. GAPDH was used as a housekeeping gene and served to normalize the results. Results. As observed in previous studies, type X collagen mRNA level was suppressed when cultured on both H- and L-PPE:N. HPPE:N was more effective in decreasing type X collagen expression than LPPE:N (55 vs. 78 % of control OA cells). Results also showed that the decreased type X collagen mRNA level was maintained not only when cells were removed from the PPE:N surfaces and transferred to new polystyrene culture dishes in the presence of chondrogenic media, but also when transferred to pellet cultures. Culturing MSCs from OA patients on PPE:N surfaces and in pellet culture had however no effect on the level of type I collagen mRNA. Conclusion. The present study confirmed the potential of PPE:N surfaces in suppressing type X collagen expression in MSCs from OA patients. More importantly, when these cells are transferred to pellet cultures, type X collagen suppression is maintained. These results may lead us one step closer to the production of large amounts of reprogrammed MSCs for tissue engineering applications

The reconstruction of bone defects with biomaterials represents a potential alternative to the transplantation of autologous and allogenic bone. Ceramic materials can be combined with growth factors (i.e. BMPs) to render them osteoinductive. Coating of biomaterials with growth factors has mostly been attempted by adsorption onto the material’s surface. The superficial deposition usually results in an immediate passive release of the proteins, thus restricting their temporal availability during bone healing. It was hypothesized that a co-precipitation of proteins onto calcium phosphate ceramics may provide the possibility to achieve a prolonged release of proteins from the material without impairing the biologic activity of growth factors. Tritium labelled bovine serum albumin ([3H]BSA) and recombinant human BMP2 (rhBMP2) were coated onto biphasic calcium phosphate (BCP) ceramics using a coprecipitation technique of proteins together with calcium phosphate (Liu Y et al. 2001). The co-precipitation was compared to conventional adsorption of proteins to ceramic materials. The passive and cell-mediated release of [3H]BSA was investigated during 19 days. To analyze the cell-mediated protein release, murine bone marrow cells were seeded onto ceramics and differentiated to osteoclasts or to monocytes/macrophages. To assess whether rhBMP2 co-precipitated to BCP ceramics retained its biologic activity the growth factor’s ability to induce the differentiation of primary murine osteoblasts was studied. After 19 days 71.7±5.3% of the adsorbed [3H]BSA was passively released (63.0±6.0% within 4 days). The passive liberation of [3H]BSA was effectively reduced using the coprecipitation technique (12.5±2.0% within 19 days, 10.1±2.3% within 4 days, p< 0.001). Further analysis demonstrated a sustained, osteoclast-mediated release of coprecipitated [3H]BSA from calcium phosphate ceramics which was blocked by the addition of calcitonin. Passive release of adsorbed and co-precipitated BMP2 led to a temporally restricted stimulation of murine osteoblasts. Cell-mediated liberation of co-precipitated BMP2 induced a sustained stimulation of the differentiation of osteoblasts. The successful application of exogenously added growth factors depends critically on the mode of delivery. It has been shown that a sustained availability of BMP2 is beneficial for bone healing. Application of the co-precipitation technique resulted in a long-term release of proteins from BCP ceramics mediated by active resorbing osteoclasts without impairing the biologic activity of rhBMP2. Co-precipitating growth factors onto BCP ceramics provides a potential to shift the initial extensive liberation to a sustained release of bioactive proteins. This method of protein delivery may represent a possibility to achieve a more physiological availability of growth factors during bone regeneration

Aims

Gap junction intercellular communication (GJIC) in osteocytes is impaired by oxidative stress, which is associated with age-related bone loss. Ageing is accompanied by the accumulation of advanced oxidation protein products (AOPPs). However, it is still unknown whether AOPP accumulation is involved in the impairment of osteocytes’ GJIC. This study aims to investigate the effect of AOPP accumulation on osteocytes’ GJIC in aged male mice and its mechanism.

Purpose: Several studies have been directed toward using mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients for cartilage or disc repair because these patients are the ones that will require a source of autologous stem cells if biological repair of tissue lesions is to be a therapeutic option. A major drawback of current cartilage and intervertebral disc tissue engineering repair is that these cells rapidly express type X collagen, a marker of late stage chondrocyte hyperthrophy implicated in endochondral ossification. However, a novel plasma-polymerized thin film material, named nitrogen-rich plasma-polymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs. The specific aim of this study was to determine if the suppression of type X collagen by PPE:N is maintained when MSCs are transferred to pellet cultures in chondrogenic defined media. Method: MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA using a protocol approved by the Research Ethics Committee of our institution. Cells were then expanded for 2–3 passages in DMEM high glucose supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 μg/ml streptomycin, and finally cultured on polystyrene (PS) cell culture dishes or PPE: N surfaces for 3 and 7 days. Cells were transferred for 3 additional days in a chondrogenic serum free media (DMEM high glucose supplemented with 2 mM L-glutamine, 20 mM HEPES, 45 mM NaHCO3, 100 U/ml penicillin, 100 μg/ml streptomycin, 1 mg/ml bovine serum albumin, 5 μg/ml insulin, 50 μg/ml ascorbic acid, 5 ng/ ml sodium selenite, 5 μg/ml transferrin) in pellet culture or on PS cell culture dishes. Cells were then lysed and proteins were separated on 4–20% acrylamide gels and transferred to nitrocellulose membranes. Type X collagen was detected by Western blot; GAPDH expression was used as an internal control for protein loading. Results: Results showed that type X collagen protein was expressed in MSCs from OA patients cultured on polystyrene but was suppressed when cultured on PPE: N. Since defined chondrogenic medium are commonly used in pellet culture to promote in vitro chondrogenesis, we then investigated the effect of transferring cells pre-cultured on PPE:N into pellet culture on type X collagen expression. However, the decreased type X collagen expression was not maintained in these conditions and that the expression returned to control values. The decreased type X collagen expression was maintained when the cells were cultured on PS cell culture dishes. Conclusion: The use of MSCs is promising for tissue engineering of cartilage and intervertebral disc. The present study confirmed the potential of PPE:N surfaces in suppressing type X collagen expression in MSCs from OA patients. However, when MSCs stem cells are transferred to pellet cultures, type X collagen is rapidly re-expressed suggesting that pellet cultures may not be suitable for chondrogenesis of MSCs from OA patients

Aims

The aim of this study is to determine the predictors of overall survival (OS) and predictive factors of poor prognosis of conventional high-grade osteosarcoma of the limbs in a single-centre in South Africa.