Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty. Aims & Objectives: This study aims to analyse the femoral periprosthetic stress-shielding following unilateral cementless total hip replacement using DEXA scan by quantifying the changes in bone mineral density around femoral component over a period of one year and identify the factors influencing the bone loss. Material & Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 3 months and 1 year after surgery in 20 patients who had undergone unilateral cementless total hip replacement, of which 10 patients had been implanted with 4/5. th. porous coated CoCr stems and other 10 patients with 1/3. rd. porous coated titanium alloy stems. Results: At both 3 months and one year postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5. th. porous coated CoCr stems in zone VII was 16.03% at 3 month and 22.42% at 1 year as compared to loss of 10.07% and 16.01% in 1/3. rd. porous coated Ti alloy stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip. Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5. th. porous coated CoCr stems as compared to 1/3. rd. porous coated titanium alloy stems

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty. Aims & Objectives: This study aims to analyse and compare prospectively the femoral periprosthetic stress-shielding around 4/5th and 1/3rd porous coated cementless femoral stems in patients undergoing unilateral cementless total hip replacement done using DEXA scan by quantifying the changes in bone mineral density around femoral component. Material & Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 years and 2 years after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated stems and other 30 patients with 1/3rd porous coated stems. Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip. Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5th porous coated stems as compared to 1/3rd porous coated stems

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty. Aims & Objectives: This study aims to analyse the femoral periprosthetic stress-shielding following unilateral cementless total hip replacement using DEXA scan by quantifying the changes in bone mineral density around femoral component. Materials and Methods: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 year and 2 year after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated CoCr stems and other 30 patients with 1/3rd porous coated titanium alloy stems. Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated CoCr stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated Ti alloy stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip. Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5th porous coated CoCr stems as compared to 1/3rd porous coated titanium alloy stems

Introduction. The purpose of this study was to evaluate the long term changes in bone mineral density (BMD) following implantation of a low-modulus composite femoral component designed to closely match the stiffness of the proximal femur and minimize stress shielding. Specifically, we asked: 1) How does BMD in the proximal femur change with time and with Gruen zone location; 2) Does BMD in the proximal femur stabilize after two years of implantation?. Methods. We retrospectively reviewed a subgroup of sixteen patients who had preoperative and postoperative DEXA scans in an FDA multi-center prospective trial of this composite stem. Five of these sixteen patients returned for long-term DEXA scans at a mean 22.0 years post-op (range 21.2–22.6 years). BMD in the 7 Gruen zones at final follow-up was compared to immediate post-operative and 2-year follow-up values. Percentage change was calculated and change in BMD was plotted against time from immediate post-operative measurements to each subsequent follow-up. Results. At the time of last follow-up, all stems were well fixed with signs of extensive osteointegration. There were no mechanical implant failures. In Gruen zone 1, patients underwent an overall decrease or little change in BMD, though one patient experienced a notable increase from initial post-op to the latest follow-up. The overall mean (+ SD) annual percent change in BMD in Gruen zone 1 was −0.31% ± 1.09%. When considering the change from the two-year DEXA scan to latest follow-up, two patients demonstrated a decrease in BMD and three patients demonstrated an increase in BMD in Gruen zone 1. All patients demonstrated progressive increase in BMD in Gruen zones 2, 3, 4, 5, and 6 from the initial post-op scan until last follow-up with mean annual percent changes ranging from 0.59% ± 0.50% in Gruen zone 6 to 2.78% ± 2.49% in Gruen zone 3. In our cohort, BMD progressively decreased with time in Gruen zone 7 for all patients with a mean decrease of 1.78% + 0.38% annually from the time of the initial post-op DEXA scan until last follow-up. This was consistent with prior reports with shorter term follow-up. Conclusions. Despite the extensively porous coated design of this stem and concerns about distal fixation and related stress shielding, we observed consistent DEXA scan evidence of increases in BMD in Gruen zones 2–6 and limitation of decreases in BMD exclusively to zone 7 and to a lesser extent zone 1. This is unlike reported results with several other extensively porous coated and proximally porous coated implants designed to obtain proximal fixation. These increases in BMD occurred despite the potential age-related decreases in BMD in the proximal femur that one would anticipate over the mean 22-year follow-up in this study. Clearly, “normal” physiologic loading of bone after THA is determined by a complex interaction between location of ingrowth, location and extent of endosteal contact of the implant in the proximal femur, stiffness of the stem and other implant design and patient related factors. The long-term observations of this study suggest that effective loading of the proximal femur occurs with this low-modulus stem and that this concept may have a role in the future of THA

Osteoporosis can cause significant disability and cost to health services globally. We aim to compare risk fractures for both osteoporosis and fractures at the L1-L4 vertebrae (LV) and the neck of femurs (NOFs) in patients referred for DEXA scan in the North-West of England. Data was obtained from 31546 patients referred for DEXA scan in the North-West of England between 2004 and 2011. Demographic data was retrospectively analysed using STATA, utilising chi-squared and t-tests. Logistical models were used to report odds ratios for risk factors included in the FRAX tool looking for differences between osteoporosis and fracture risk at the LV and NOFs. In a study involving 2530 cases of LV fractures and 1363 of NOF fractures, age was significantly linked to fractures and osteoporosis at both sites, with a higher risk of osteoporosis at NOFs compared to LV. Height provided protection against fractures and osteoporosis at both sites, with a more pronounced protective effect against osteoporosis at NOFs. Weight was more protective for NOF fractures, while smoking increased osteoporosis risk with no site-specific difference. Steroids were unexpectedly protective for fractures at both sites, with no significant difference, while alcohol consumption was protective against osteoporosis at both sites and associated with increased LV fracture risk. Rheumatoid arthritis increased osteoporosis risk in NOFs and implied a higher fracture risk, though not statistically significant compared to LV. Results summarised in Table 1. Our study reveals that established osteoporosis and fracture risk factors impact distinct bony sites differently. Age and rheumatoid arthritis increase osteoporosis risk more at NOFs than LV, while height and steroids provide greater protection at NOFs. Height significantly protects LV fractures, with alcohol predicting them. Further research is needed to explore risk factors’ impact on additional bony sites and understand the observed differences’ pathophysiology. For any figures or tables, please contact the authors directly

Abstract. Objective. This study assesses the prevalence of major and minor discordance between hip and spine T scores using Radiofrequency Echographic Multi-spectrometry (REMS). REMS is a novel technology that uses ultrasound and radiofrequency analysis to measure bone density and bone fragility at the hip and lumbar spine. The objective was to compare the results with the existing literature on Dual-Energy X-ray Absorptiometry (DEXA) the current “gold standard” for bone densitometry. REMS and DEXA have been shown to have similar diagnostic accuracy, however, REMS has less human input when carrying out the scan, therefore the rates of discordance might be expected to be lower than for DEXA. Discordance poses a risk of misclassification of patients’ bone health status, causing diagnostic ambiguity and potentially sub-optimal management decisions. Reduction of discordance rates therefore has the potential to significantly improve treatment and patient outcomes. Methods. Results from 1,855 patients who underwent REMS investigations between 2018 and 2022 were available. Minor discordance is defined as a difference of one World Health Organisation (WHO) diagnostic classification (Normal / Osteopenia or Osteopenia / Osteoporosis). Major discordance is defined as a difference of two WHO diagnostic classifications (Normal / Osteoporosis). The results were compared with reported DEXA discordance rates. Results. 1,732 individuals had both hip and spine T scores available for analysis. There were 267 cases of discordance. No instances of major discordance were observed. The minor discordance rate was 15.4%. 6.5% of the REMS scans with minor discordance showed > 1.0 standard deviation (SD) difference between the T scores of the hip and spine. 19.4% had differences of between 0.6 SD and 1.0 SD while 73.9% had ≤ 0.5 SD or less. In 24.5% of the cases of REMS discordance the hip T scores were greater than the spine and in 75.5% of cases the spine T score was greater than the hip. Conclusions. The current analysis is the largest of its kind. It demonstrates that REMS has an overall lower rate of discordance than reported DEXA rates. Major discordance rates with DEXA range from 2–17%, but REMS avoids many of the positioning problems and post-processing errors inherent in DEXA scanning, which might account for the absence of major discordance. Rates of minor discordance in DEXA scans range between 38–51%. The REMS minor discordance rate being much lower than these rates suggests that it has the potential to enhance diagnostic accuracy considerably. Most REMS discordance results showed ≤ 0.5 SD variance between the T scores of the two sites, indicating close correlation in the bone densitometry analysis. Most studies of DEXA discordant results confirm that spinal T scores are more often higher than at the hip. The REMS results concur with this observation. Considering the comparable accuracy rates that have been shown between REMS and DEXA, with its much lower discordance rate, REMS can potentially improve current medical practice and enhance patient care. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

An audit was carried out to assess the management of patients with fragility fractures in fracture clinic and primary care. NICE guidelines advise these patients require treatment for osteoporosis if 75 years or older, and a DEXA scan if below this age. Distal radius and proximal humeral fractures were identified in a retrospective review of letters from 10 fracture clinics. Current medication of all patients ≥ 75 years was accessed and DEXA scan requests identified for patients < 75 years. There were 69 fragility fractures: 53 distal radius and 16 proximal humerus. 4 letters (6%) mentioned fragility fracture and advised treatment and 3 (3%) correctly advised a DEXA scan. Only 3 of 25 (10%) patients ≥ 75yrs not previously on osteoporosis medication had treatment started by their GPs. 3 of a possible 29 (10%) patients < 75 years were referred for a DEXA scan. A text box highlighting fragility fractures and NICE guidelines was added to all clinic letters for patient ≥ 50 years old. Re-audits showed an improvement in management of these fractures, with 45% of patients ≥ 75 years being started on treatment and 39% of patients < 75 years being referred for a DEXA scan

Introduction. Modular dual mobility (MDM) prostheses are increasingly utilized for total hip arthroplasty (THA) to mitigate the risk of postoperative instability in high risk patients. Short-term reports on clinical outcomes are favorable but there are few studies on young active patients. This study quantified proximal femoral stress shielding and metal ion release in MDM combined with modern cementless stem design in young active patients. Methods. This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2 and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. DEXA scans were performed at 6 weeks postoperatively as a baseline, then again at 6 months, 1 year, 2 years and 5 years postoperatively as were metal ions. Results. A total of 43 patients (30 male, 13 female; mean age 52.6 years (sd 6.5)) were enrolled. At the time of analysis, 14 patients had completed DEXA scans at 5 years postoperatively. There was no significant loss of proximal femoral bone mineral density in Gruen Zones 1–7 or acetabular bone mineral density in Gruen Zones 1–6 between 6 weeks and 5 years postoperatively (p > 0.05 for each zone). Sixteen patients had metal ions at 5yrs. Cobalt levels averaged .07 ppb (range .012 – .451) and chromium levels averaged 0.24 ppb (range .092 – .883). Conclusion. At a minimum 5 years follow up, MDM with a modern cementless stem demonstrated minimal stress shielding and no concerning metal ion release in young active patients

Background. Reduced bone mineral density is recognised as a risk factor for hip fractures and fragility fractures in general. Vitamin D is important in maintaining healthy bone mineral levels and can therefore affect risk of hip fracture. We investigated the correlation between vitamin D levels and bone mineral density, as well as fracture type, in neck of femur fractures and also assessed the relationship of vitamin D and social deprivation. Method. We included all patients admitted to our department, with a neck of femur fracture over one year (October 2013 to October 2014). We analysed vitamin D levels for all patients during admission and compared these to bone mineral density scores, based on DEXA scan results; hip fracture type & comminution, based on admission radiographs; and levels of social deprivation, based on the patient's address. Results. In total 360 patients were admitted over the study period, with a neck of femur fracture, of which 298 had vitamin D assessed and 76 had DEXA scans. Of these cohorts, 71% were found to be vitamin D deficient and 7% had osteoporosis. No significant correlation was found between vitamin D scores and bone density, or with level of vitamin D deficiency and fracture type or comminution. A significant correlation was however identified, between low vitamin D levels and decreasing levels of social deprivation (R=0.11, p=0.04). Conclusion. No relationship was identified between vitamin D levels and hip fracture type, suggesting that vitamin D cannot be used to predict patients at risk of more comminuted fractures. Although no relationship was also identified for bone mineral density and vitamin D, this may be because the sample size of DEXA scans was relatively small. Interestingly the relationship between vitamin D and social deprivation was the reverse of what was expected and suggests that affluent individuals may be at greater risk of low vitamin D

Introduction: The incidence of osteoporosis is increasing as the population ages. Amongst the recommended treatment modalities for osteoporosis is the use of bisphosphonates. The National Osteoporosis Foundation (U.S.A.) recommends DEXA scanning prior to commencing treatment with bisphosphonate therapy. However, in the Irish setting the availability of DEXA scanning is often limited. We hypothesised that a high percentage of elderly women presenting with fragility fractures of the distal radius (following a simple fall from standing height) had underlying osteoporosis. As such, the initiation of treatment with bisphosphonates prior to obtaining a DEXA scan may be warranted in this patient cohort. Aim: To assess the incidence of osteoporosis in a continuous cohort of women over 60 years of age presenting with fractures of the distal radius. Patients and Methods: All female patients aged > 60 years old presenting to the fracture service over a five month period with distal radial fragility fractures were evaluated. Exclusion criteria included:. non-English speakers. non-resident in Ireland. previous diagnosis of osteoporosis or commenced on treatment for osteoporosis. not fit to attend for DEXA scan. not willing to participate in the study. 100 consecutive patients presenting to the fracture service with distal radial fragility fractures were prospectively identified. Data was collected, including body mass index (BMI), risk factors for osteoporosis, and the OST risk index calculated. A DEXA scan was then performed on the patient’s hips and lumbar spine. Results: The mean patient age was 74.3 (95%CI + 10.6) years. Mean BMI was 17.3 kg/m2. The mean Osteoporosis Self-assessment Tool (OST) index score was 0.65 correlating with a moderate risk for osteoporosis. The mean T score for the patients’ hips was −2.0 while that for the lumbar spine was −1.7. 64% of patients were osteoporotic with a T score of less than −2.5. Conclusions A significant incidence of osteoporosis was noted in the study cohort. It is imperative that orthopaedic surgeons recognise the high incidence of osteoporosis in the elderly female population presenting with fragility fractures. The high morbidity and mortality associated with hip and vertebral fractures in this population may be prevented by early treatment of underlying osteoporosis

To discover whether orthopaedic surgeons follow the BOA guidelines for secondary prevention of fragility fractures, a retrospective audit on neck of femur fractures treated in our hospital in October/November 2003 was carried out. There were 27 patients. Twenty-six patients (96%) had full blood count measured. LFT and bone-profile were measured in 18 patients (66%). Only nine patients (30%) had treatment for osteoporosis (calcium and vitamin D). Only one patient was referred for DEXA scan. Steps were taken to create better awareness of the BOA guidelines among junior doctors and nurse practitioners. In patients above 80 years of age it was decided to use abbreviated mental score above 7 as a clinical criterion for DEXA referral. A hospital protocol based on BOA guidelines was made. A re-audit was conducted during the period August-October 2004, with 37 patients. All of them had their full blood count and renal profile checked (100%). The bone-profile was measured in 28 (75.7%) and LFT in 34 (91.9%) patients. Twenty-four patients (65%) received treatment in the form of calcium + Vit D (20) and bisphosphonate (4). DEXA scan referral was not indicated in 14 patients as 4 of them were already on bisphosphonates and 10 patients had an abbreviated mental score of less than 7. Among the remaining 23 patients, nine (40%) were referred for DEXA scan. This improvement is statistically significant (p=0.03, chi square test). The re-audit shows that, although there is an improvement in the situation, we are still below the standards of secondary prevention of fragility fractures with 60% of femoral fragility fracture patients not being referred for DEXA scan. A pathway lead by a fracture liaison nurse dedicated to osteoporotic fracture patients should improve the situation

The primary purpose of this study was to evaluate the appropriate use of Dual Energy X-ray absorptiometry (DEXA) scanning in the follow-up of osteoporosis. The secondary aim was to ascertain the correlation between body mass index (BMI) and osteoporosis in the study population. Six hundred and sixty six patients were sent for DEXA scanning from the Osteoporosis clinic at 1-Military Hospital from June 1998 to February 2004. A descriptive expost facto study of primary data was undertaken, consisting of patient records, test results and post treatment test results. Patients were classified according to their World Health Organization (WHO) classification of bone density. Each of the categories was then followed-up to determine an improvement or deterioration in a specific category. A total number of 307 (46.1%) follow-up DEXA scans were done over a period of five years. The majority of patients’ bone mineral density (BMD) remained in the same WHO category while a significant number improved to a higher category. The biggest improvement was in elevating patients from an osteoporosis category to an osteopenic category. Only a small number of patients’ BMD deteriorated. A significant positive correlation between BMI and T-scores for all the patients who received DEXA scans was found. It is therefore apparent that it is safe to follow-up patients with osteoporosis by means of DEXA scanning only once every four to five years. The correlation between BMI and bone mineral density, might serve as a useful guide to identify patients qualifying for more frequent follow up scans

Aim: to determine the proportion of patients with fragility fractures who underwent risk assessment for osteoporosis as a result of their fracture clinic attendance prior to and following reinforcement of guidelines. Methods: The inclusion criteria were defined as: new patients fifty years of age or over sustaining a fragility fracture of their distal radius presenting during two three month periods in 2004 (April to June and October to December). Guidelines for osteoporosis risk assessment (the Northumberland guidelines) were reinforced during the interim period. Patients were identified from hospital records and the notes obtained to confirm the fracture type as fragility. The number assessed during each period was determined from outpatient referral for DEXA records and compared. Patients who had undergone DEXA scanning in the year prior to their fracture clinic attendance were excluded from the analysis. Results: from April to June there were forty-six patients (39 women and 7 men) with a mean age of 73 years while between October and December there were fifty-four patients (48 women and 6 men) with an average age of 68 years. In the April to June cohort 3 patients had already had a DEXA scan prior to fracture clinic attendance. Of the 43 remaining patients 3 were risk assessed for osteoporosis (7%). Within the October to December group two patients had previously undergone DEXA scanning and of the remaining 52 patients 16 (31%) underwent osteoporosis risk assessment. Conclusion: Risk assessment for osteoporosis is still carried out ineffectively by orthopaedic surgeons even following enforcement of guidelines

Osteoporosis is common in elderly patients and is commonly associated with fractures of the neck of the femur. It is known that this condition is not treated optimally by orthopaedic services around the world. We aim to examine the level of osteoporosis treatment in this fracture and how effective we were in improving treatment for osteoporosis. We retrospectively examined hospital documents from patients admitted between 1 January and 31 December 2004 with femoral neck fracture. All notes were retrieved and were complete. We examined the medications on admission, the place of residence, place of discharge, frequency of DEXA scanning and medications. One hundred and twenty patients were admitted with fracture of the neck of the femur. This group consisted of 23 males with an average age of 76.7, 97 females with an average age of 83.7. Seventy five of these patients were admitted from home, 45 from a rest home. Four patients died prior to treatment, one refused treatment and subsequently died in a hospice. Osteoporotic medications on admission showed that 13 patients were on Bisphosphonate, 6 on Vitamin D and twelve on calcium supplements. Only 14 patients had had DEXA scans prior to admission. On admission eight patients were on no medications of any sort, 53 were on 1–4 medications, 53 were on 5–9 medications and 6 were on greater than 10 medications. On discharge from orthopaedic of the 120 patients 13 were on Bisphosphonate, six on Vitamin D, 13 on calcium supplements. Six patients were on no medications, 47 on 1–4 medications, 55 on 5–9 medications, nine on greater than 10 medications. On discharge from geriatric service, to which 69 patients had been referred 25 were on Bisphosphonate, 13 on Vitamin D, 18 on calcium supplements. One patient was on no medication. 20 were on 1–4 medications, 41 on 5–9 medications and seven on greater than 10 medications. Fifty four had had DEXA scans. We found that the rate of treatment of osteoporosis in the community remains poor with no improvement while in the orthopaedic service. On discharge from the geriatric service significant improvement in osteoporotic medication occurred but there was also an increased in polypharmacy. Further work on the investigation and treatment of osteoporosis in this country is required

Summary. Arginine supplementation is helpful in treatment of osteoporosis. Introduction. Nitric oxide (NO) is a short-lived free radical involved in several biological processes as a bioregulator and as a second messenger. It inhibits osteoclastic bone resorption in vitro and regulates bone remodeling. Zolendronic acid has been established as a treatment for post menopausal osteoporosis. Study was done to compare the efficacy of Nitic oxide donor (L-arginine) with that of Zolendronic acid for the treatment of osteoporosis. Method. The study was not designed to compare these two drugs against a placebo, because the beneficial effects of Zolendronic acid in treatment of osteoporosis are well established. Institutional Review Board approvals were obtained. One hundred patients of osteoporosis having T score of −2.5 or more, were randomised to receive L-arginine) or Zolendronic acid. All patients received 1.0 g of calcium and 400 IU of vitamin D supplementation per day. In addition Group I patients received L-arginine (2 gm.) per day while Group II patients received zoledronic acid 5 mg i.v. over 15 min. Patient were followed at regular intervals clinically, by biochemical investigations and at one year for DEXA scan. Results. Patients in both groups improved clinically and bio-chemically over one year period. T score on DEXA scan at one year showed improvement in bone density. Average pretreatment T score was −3.65 in group I and −3.52 in group II. At one year followup average T score was −2.9 in group I and −2.6 in group II. Difference was not statistically significant. Discussion. Oral administration of L-arginine in pharmacological doses induces growth hormone and insulin like growth factor-1 responses and stimulates nitric oxide synthesis. Growth hormone and insulin like growth factor-1 are important mediator of bone turnover and osteoblastic bone formation. While nitric oxide is potent inhibitor of osteoclastic bone resorption because of this dual effect on physiological regulator of bone remodeling. L-arginine could potentially increase bone formation over bone resorption and consequently increase bone mass. Oral supplementation of L-arginine may be novel strategy in prevention and treatment of osteoporosis

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty. Aims & Objectives: This study aims to analyse and compare prospectively the femoral periprosthetic stress-shielding around 4/5th and 1/3rd porous coated cementless femoral stems in patients undergoing unilateral cementless total hip replacement done using DEXA scan by quantifying the changes in bone mineral density around femoral component. Material & Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 years and 2 years after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated stems and other 30 patients with 1/3rd porous coated stems. Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip. Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5. th. porous coated stems as compared to 1/3. rd. porous coated stems

Background: Joint replacements are being performed on ever younger patients at a time when average expectancy of life is continuing to rise. Any reduction in the strength and mass of periprosthetic bone could threaten the longevity of implant by predisposing to loosening and migration of prosthesis, periprosthetic fracture and problems in revision arthroplasty. Aims and Objectives: This study aims to analyse and compare prospectively the femoral periprosthetic stress-shielding around 4/5th and 1/3rd porous coated cementless femoral stems in patients undergoing unilateral cementless total hip replacement done using DEXA scan by quantifying the changes in bone mineral density around femoral component. Material and Method: Femoral periprosthetic bone mineral density was measured in the seven Gruen Zones with DEXA scan at 2 weeks, 1 years and 2 years after surgery in 60 patients who had undergone unilateral cementless total hip replacement, of which 30 patients had been implanted with 4/5th porous coated stems and other 30 patients with 1/3rd porous coated stems. Results: At both one and two years postoperatively, bone loss due to stress-shielding was seen in both stems with maximum loss in zone VII and minimum in zone III, IV, V. The maximum mean percentage bone mineral density loss in 4/5th porous coated stems in zone VII was 16.03% at one year and 22.42% at 2 years as compared to loss of 10.07% and 16.01% in 1/3rd porous coated stems. Increased bone loss was seen in patients who had larger diameter stem (> 13.0 mm) and in patients with low bone mineral density in the unoperated hip. Conclusion: Bone loss as a result of stress-shielding is more pronounced in 4/5th porous coated stems as compared to 1/3rd porous coated stems

Introduction. Melatonin-deficient rats are known to develop scoliosis when rendered bipedal. In a previous study we have shown that melatonin-deficient bipedal mice with scoliosis had lower bone density than did mice without scoliosis. Published work suggests that children with AIS have lower bone density than do healthy children. The aim of this study is to establish whether osteoporosis causes scoliosis. We hypothesised that bipedal rats with lower bone density would have increased spinal malalignment compared with the control group. Methods. 50 female Sprague-Dawley rats were rendered bipedal at 3 weeks of age by amputation of the forelimbs and tails. Two groups were formed: control group (n=25), in which rats received no drug; and the experiment group (n=25), in which rats received daily subcutaneous 1 U/g heparin injections. Animals were kept in standard cages, and food and water was provided at the top of the cages to encourage more time standing erect. DEXA scans were done on week 4 to assess bone density. Radiographs were taken on week 40 to assess spinal alignment in both control and experiment groups. Results. 19 rats in the heparin group and 23 rats in the control group were available for evaluation at the end of the study. At week 4, DEXA scans showed significant difference between the bone densities of the control and heparin groups (p<0·05), with the heparin group having lower bone density. The incidence of curves between the heparin and control groups were not statistically significant (p>0·01) (table). The magnitude of curves in scoliotic rats for the heparin group was 11·8° (SD 3·75) and for the control group 10° (4·3). The difference between the groups was not significant (p>0·05). Conclusions. This study involved rats with normal melatonin levels and both groups showed a high frequency of scoliosis incidence. Although no significant differences were recorded between groups, the results suggest that bipedality is a cause for scoliosis, and low bone mineral density may further increase this tendency

We aimed to audit the results of one stop fragility fracture risk assessment service at fracture clinic for non-hip fractures in 50–75 years old patients at Newcastle General Hospital. Currently, fewer than 30% of patients with fragility fractures benefit from secondary prevention in the form of comprehensive risk assessment and bone protection because of multifactorial reasons. We have a fragility fracture risk assessment service staffed by an Osteoporosis Specialist Nurse equipped with a DEXA scanner located at the fracture clinic itself. We carried out a retrospective audit of 349 patients of 50–75 years with suspected non-hip fractures referred from A& E Department from October 2006 to September 2007. Patients over 75 years were excluded because as per NICE guidelines, they should receive bone protection without need of a DEXA scan. Out of these 349 patients with suspected fractures, 171 had fragility fractures. Median age was 64 years. 69 patients had humerus fracture, 65 had forearm fracture and 23 patients had ankle fracture and 14 had metatarsal fractures. Fracture risk assessment was carried out in 120 (70%) patients. Thirty Seven (31%) patients had osteoporosis and bone protection was recommended to GP. 38 (32%) had osteopenia and lifestyle advice was provided. 45 (37%) had normal axial bone densitometry. 90% patients had DEXA scan at the same time of fracture clinic appointment. Patients with male gender, undisplaced fracture and fewer fracture clinic appointments were more likely to miss fracture risk assessment. Our experience suggests that locating fragility fracture risk assessment service co-ordinated by an Osteoporosis Specialist Nurse at fracture clinic is an efficient way of providing secondary prevention for patients with fragility fractures. This can improve team communication, eliminate delay and improve patient compliance because of ‘One Stop Shop’ service at the time of fracture clinic appointment

We aimed to establish if radiological parameters, dual energy x-ray absorbtiometry (DEXA) and quantitative CT (qCT) could predict the risk of sustaining a femoral neck fracture following hip resurfacing. Twenty-one unilateral fresh frozen femurs were used. Each femur had a plain AP radiograph, DEXA scan and quantitative CT scan. Femurs were then prepared for a Birmingham Hip Resurfacing femoral component with the stem shaft angle equal to the native neck shaft angle. The femoral component was then cemented onto the prepared femoral head. No notching of the femoral neck occurred in any specimens. A repeat radiograph was performed to confirm the stem shaft angle. The femurs were then potted in a position of single leg stance and tested in the axial direction to failure using an Instron mechanical tester. The load to failure was then analysed with the radiological, DEXA and qCT parameters using multiple regression. The strongest correlation with the load to failure values was the total mineral content of the femoral neck at the head/neck junction using qCT r= 0.74 (p< 0.001). This improved to r=0.76 (p< 0.001) when neck width was included in the analysis. The total bone mineral density measurement from the DEXA scan showed a correlation with the load to failure of r=0.69 (p< 0.001). Radiological parameters only moderately correlated with the load to failure values; neck width (r=0.55), head diameter (r= 0.49) and femoral off-set (r=0.3). This study suggests that a patient’s risk of femoral neck fracture following hip resurfacing is most strongly correlated with total mineral content at the head/neck junction and bone mineral density. This biomechanical data suggests that the risk of post-operative femoral neck fracture may be most accurately identified with a pre-operative quantitative CT scan through the head/neck junction combined with the femoral neck width