We measured the extent and rate of new bone formation over an 18-month period before, during and after the lengthening of ten leg segments in six patients aged between 8 and 18 years, using dual-energy X-ray absorptiometry (DEXA). New bone formation could be identified within one week of the start of distraction. As lengthening proceeded, the bone density of the gap fell, reaching minimum values at the time of maximal distraction. Consolidation of the regenerating bone was started 1 to 2 weeks later in the tibia, and 2.5 to 3.0 weeks later in the femur. The rate of mineral accretion in new bone was significantly greater in the tibia than in the femur (16 +/- 1.86%/month, and 11 +/- 1.1%/month respectively; mean +/- SEM). There was significant osteoporosis distal to the osteotomy, more in the tibia than in the femur, particularly on the side of the fixator. The bone mineral density of the distal segment remained low at the time of fixator removal (44.2 +/- 5.58% and 61.0 +/- 4.2% of the control values at the tibia and femur respectively) and was only partially reversed by subsequent weight-bearing. We conclude that dual-energy X-ray absorptiometry provides an objective and quantitative assessment of new bone formation during leg lengthening. The technique also allows the measurement of the distraction gap and the assessment of leg alignment from the high-resolution images. Its use may decrease the requirements for conventional radiography

We evaluated changes in bone mineral density (BMD) after tibial fractures, both at the site of fracture and at adjacent sites, using dual-energy X-ray absorptiometry. Five patients were studied prospectively for six months after fractures of the midshaft treated by intramedullary nailing or the application of an external fixator. We also reviewed 21 adult and 10 children who had sustained fractures of the tibia at least five years previously, comparing BMD in the injured limb with that in the non-injured limb and in a control group of 10 normal subjects. We found a significant fall in BMD distal to a tibial fracture; this was evident at one month, fell to approximately 50% of normal at three months and persisted at six months. We found no significant improvement with weight-bearing. Review at 5 to 11 years after adult midshaft fractures showed persistent bone loss in the distal tibia (46.5 +/- 9.8% of control values), but persisting sclerosis at old fracture sites (172 +/- 38% of control values). In contrast, we found no significant differences in BMD between the injured and control limb after fractures sustained in childhood either at the fracture site or in the distal segment. We conclude that, in adults, tibial fractures are associated with definite and persistent post-traumatic loss of distal BMD

Purpose: The goal of this study was to evaluate the use of dual energy x-ray absorptiometry (DEXA) to subjectively assess distraction osteogenesis callous regenerate strength to aid in the determination of when to remove the external fixator device in patients undergoing distraction osteogenesis for limb length discrepancies. Methods: All patients that underwent distraction osteogenesis with either an Ilizarov or Orthofix frame from 1984 to 2005 at the Montréal Shriners Hospital Canada that had monthly DEXA scans prior to removal of their external fixators were included. The fixators were removed once two consecutive DEXA scans showed that the bone mineral density (BMD) had plateaued with a less than 10% successive increase in BMD. A retrospective chart and radiographical review was performed to assess the healing index and post fixator removal complications. Results: 30 patients underwent 32 corrections. There were 29 lengthenings and 3 lengthenings with angular corrections. The average lengthening was 5.4 cm (3.6–9.1). The healing index average was 49 days/cm (20–77). All patients were progressed from partial to full weightbearing within 6 weeks of fixator removal. There were 2 post removal fractures. One patient fractured through the regenerate and another fractured through a proximal pin site. Conclusions: Current methods of assessing distraction osteogenesis callous prior to removal of fixator are objective methods based on plain radiographs that have been shown to have poor interobserver reliability. Fractures occurring after fixator removal range between 10–15%. Using DEXA to determine when the regenerate bone mineral density and thus bone strength has plateaued yielded a post fixator removal regenerate fracture rate of 3% in our review. This new method of subjectively assessing the regenerate as compared to other objective radiological methods is a reliable alternative that safely predicts when to remove the fixator with a low post removal fracture rate while maintaining an acceptable bone healing index

Introduction. Precision error (PE) in Dual Energy X-Ray Absorptiometry (DXA) is important for accurate monitoring of changes in Bone-Mineral-Density (BMD). It has been demonstrated that BMD PE increases with increasing BMI. In vivo PE for the Trabecular-Bone-Score (TBS) has not been reported. This study aimed to evaluate the short-term PE (STPE)) of BMD and TBS and to investigate the effect of obesity on DXA PE. Method. DXA lumbar spine scans (L1–L4) were performed using GE Lunar Prodigy. STPE was measured in 91 women (Group A) at a single visit by duplicating scans with repositioning in-between. PE was calculated as the percentage coefficient of variation (%CV). Group A was sub-divided into four groups based on BMI (A.1. <25kg/m2, A.2. 25–29.9kg/m2, A.3. 30–35kg/m2 and A.4. >35kg/m2) to assess the effect of obesity on STPE. Abnormally different vertebrae were excluded from the analysis in accordance with The International Society for Clinical Densitometry (ISCD) recommendations. Results. The Group A STPE was 1.26 % for BMD and 2.04% for TBS. Short-term PE for BMD and TBS respectively in the BMI subgroups was: A.1. 1.07% and 1.82%, A.2. 1.34% and 2.26%, A.3. 1.25% and 2.35%, A.4. 1.68% and 1.82%. Conclusion. The results show that STPE is higher for TBS than for BMD. Short-term PE for both BMD and TBS are adversely affected by increasing BMI but this effect is mitigated in the highest BMI category where use of the ‘thick’ scanning mode improves signal to noise ratio

Aims. This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images. Methods. The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm. 3. ). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis. Results. CT-aBMD was successfully measured in 976/978 hips (99.8%). A significant correlation was found between CT-aBMD and DXA-BMD (r = 0.941; p < 0.001). In the ROC analysis, the area under the curve to diagnose osteoporosis was 0.976. The diagnostic sensitivity and specificity were 88.9% and 96%, respectively, with the cutoff set at 0.625 g/cm. 2. . Conclusion. Accurate DXA-BMD measurements and diagnosis of osteoporosis were performed from CT images using the system developed herein. As the models are open-source, clinicians can use the proposed system to screen osteoporosis and determine the surgical strategy for hip surgery. Cite this article: Bone Joint Res 2023;12(9):590–597

Aims. Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation. Methods. Retrospective chart review of a single-surgeon database identified 78 patients with CTXA performed prior to robotic-assisted THA (raTHA) (Group 1). Group 1 was age- and sex-matched to 78 raTHAs that had a preoperative hip CT but did not have CTXA analysis (Group 2). Clinical demographics, femoral fixation method, CTXA, and DXA data were recorded. Demographic data were similar for both groups. Results. Preoperative femoral BMD was available for 100% of Group 1 patients (CTXA) and 43.6% of Group 2 patients (DXA). CTXA analysis for all Group 1 patients preoperatively identified 13 osteopenic and eight osteoporotic patients for whom there were no available preoperative DXA data. Cemented stem fixation was used with higher frequency in Group 1 versus Group 2 (28.2% vs 14.3%, respectively; p = 0.030), and in all cases where osteoporosis was diagnosed, irrespective of technique (DXA or CTXA). Conclusion. Preoperative hip CT scans which are routinely obtained prior to raTHA can determine bone health, and thus guide femoral fixation strategy. Systematic preoperative evaluation with CTXA resulted in increased recognition of osteopenia and osteoporosis, and contributed to increased use of cemented femoral fixation compared with routine clinical care; in this small study, however, it did not impact short-term periprosthetic fracture risk. Cite this article: Bone Joint J 2023;105-B(3):254–260

Aims. Osteoporosis is common in total hip arthroplasty (THA) patients. It plays a substantial factor in the surgery’s outcome, and previous studies have revealed that pharmacological treatment for osteoporosis influences implant survival rate. The purpose of this study was to examine the prevalence of and treatment rates for osteoporosis prior to THA, and to explore differences in osteoporosis-related biomarkers between patients treated and untreated for osteoporosis. Methods. This single-centre retrospective study included 398 hip joints of patients who underwent THA. Using medical records, we examined preoperative bone mineral density measures of the hip and lumbar spine using dual energy X-ray absorptiometry (DXA) scans and the medications used to treat osteoporosis at the time of admission. We also assessed the following osteoporosis-related biomarkers: tartrate-resistant acid phosphatase 5b (TRACP-5b); total procollagen type 1 amino-terminal propeptide (total P1NP); intact parathyroid hormone; and homocysteine. Results. The prevalence of DXA-proven hip osteoporosis (T-score ≤ -2.5) among THA patients was 8.8% (35 of 398). The spinal osteoporosis prevalence rate was 4.5% (18 of 398), and 244 patients (61.3%; 244 of 398) had osteopenia (-2.5 < T-score ≤ -1) or osteoporosis of either the hip or spine. The rate of pharmacological osteoporosis treatment was 22.1% (88 of 398). TRACP-5b was significantly lower in the osteoporosis-treated group than in the untreated group (p < 0.001). Conclusion. Osteoporosis is common in patients undergoing THA, but the diagnosis and treatment for osteoporosis were insufficient. The lower TRACP-5b levels in the osteoporosis-treated group — that is, osteoclast suppression — may contribute to the reduction of the postoperative revision rate after THA. Cite this article: Bone Joint Res 2022;11(12):873–880

We used dual-energy X-ray absorptiometry (DEXA) to measure the bone mineral content (BMC) of both tibiae in 13 patients who had been treated for a tibial fracture by rigid plate fixation. Within two weeks of plate removal the BMC was significantly greater in the bone that had been under the plate than at the same site in the control tibia. An unplated area of bone near the ankle showed a significant decrease in BMC at the time of plate removal with subsequent return to the level of the control tibia during the ensuing 18 months. We conclude that osteoinductive influences outweigh the potential causes of osteopenia, such as stress shielding and disuse, and that, contrary to expectation, demineralisation is not a factor in the diminished strength of the tibia after plating for fracture

Aims. Assessment of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) is a well-established clinical technique, but it is not available in the acute trauma setting. Thus, it cannot provide a preoperative estimation of BMD to help guide the technique of fracture fixation. Alternative methods that have been suggested for assessing BMD include: 1) cortical measures, such as cortical ratios and combined cortical scores; and 2) aluminium grading systems from preoperative digital radiographs. However, limited research has been performed in this area to validate the different methods. The aim of this study was to investigate the evaluation of BMD from digital radiographs by comparing various methods against DXA scanning. Methods. A total of 54 patients with distal radial fractures were included in the study. Each underwent posteroanterior (PA) and lateral radiographs of the injured wrist with an aluminium step wedge. Overall 27 patients underwent routine DXA scanning of the hip and lumbar spine, with 13 undergoing additional DXA scanning of the uninjured forearm. Analysis of radiographs was performed on ImageJ and Matlab with calculations of cortical measures, cortical indices, combined cortical scores, and aluminium equivalent grading. Results. Cortical measures showed varying correlations with the forearm DXA results (range: Pearson correlation coefficient (r) = 0.343 (p = 0.251) to r = 0.521 (p = 0.068)), with none showing statistically significant correlations. Aluminium equivalent grading showed statistically significant correlations with the forearm DXA of the corresponding region of interest (p < 0.017). Conclusion. Cortical measures, cortical indices, and combined cortical scores did not show a statistically significant correlation to forearm DXA measures. Aluminium-equivalent is an easily applicable method for estimation of BMD from digital radiographs in the preoperative setting. Cite this article: Bone Joint Res 2021;10(12):830–839

Aims. The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). Methods. The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded. Results. There were significantly larger contact areas in Gruen zones 3, 5, and 6 in the N-HA group than in the T-HA group. At two years postoperatively, there was a significant decrease in BMD around the proximal-medial femur (zone 6) in the N-HA group and a significant increase in the T-HA group. BMD changes in both groups correlated with BMI or preoperative lumbar BMD rather than with the extent of contact with the femoral cortical bone. Conclusion. The N-HA-coated stem showed a significantly larger contact area, indicating a distal fixation pattern, compared with the traditional fully HA-coated stem. The T-HA-coated stem showed better preservation of periprosthetic BMD, two years postoperatively. Surgeons should consider these patterns of fixation and differences in BMD when selecting fully HA-coated stems for THA, to improve the long-term outcomes. Cite this article: Bone Joint J 2024;106-B(6):548–554

We studied the quantity and rate of formation of new bone during lengthening of 17 limb segments in 10 patients using dual-energy X-ray absorptiometry (DEXA), ultrasonography and radiography. Whereas new bone was detected by both DEXA and ultrasonography within 1 to 2 weeks of distraction, it was not visible on the radiographs until 4 to 8 weeks. Limb alignment and gap measurement were accurately assessed by DEXA without the need for standard radiographs or scanograms. With ultrasound the distraction gap appeared as an echolucent window which narrowed progressively producing a hyper-reflecting line after which further consolidation could not be assessed. As measured by DEXA the density of the new bone at this stage was approximately 45% of control values and did not represent normal cortication. Whereas ultrasound could be used to identify defects in mineralisation and to determine when to dynamise the fixator system, DEXA could measure the quantity and rate of formation of bone throughout lengthening

Aims. Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems. Methods. In total, 44 patients with bilateral hip osteoarthritis were recruited from the outpatient clinic at a single tertiary orthopaedic centre. The patients were operated with bilateral one-stage total hip arthroplasty. The most painful hip was randomized to either Fitmore or CLS femoral component; the second hip was operated with the femoral component not used on the first side. Patients were evaluated at three and six months and at one, two, and five years postoperatively with patient-reported outcome measures, radiostereometric analysis, dual-energy X-ray absorptiometry, and conventional radiography. A total of 39 patients attended the follow-up visit at two years (primary outcome) and 35 patients at five years. The primary outcome was which hip the patient considered to have the best function at two years. Results. At two and five years, more patients considered the hip with the CLS femoral component as superior but without a statistically significant difference. There were no differences in clinical outcome, magnitude of femoral component migration, or change of bone mineral density at five years. At three months, the Fitmore femoral component had subsided a median -0.71 mm (interquartile range (IQR) -1.67 to -0.20) and the CLS femoral component -0.70 mm (IQR -1.53 to -0.17; p = 0.742). In both groups the femoral head centre had migrated posteriorly (Fitmore -0.17 mm (IQR -0.98 to -0.04) and CLS -0.23 mm (IQR -0.87 to 0.07; p = 0.936)). After three months neither of the femoral components showed much further migration. During the first postoperative year, one Fitmore femoral component was revised due to aseptic loosening. Conclusion. Up to five years, we found no statistically significant difference in outcomes between the Fitmore and the CLS femoral components. The slightly worse outcomes, including one revised hip because of loosening, speaks against the hypothesis that the Fitmore femoral component should be advantageous compared to the CLS if more patients had been recruited to this study. Cite this article: Bone Jt Open 2023;4(5):306–314

Aims. To analyze the short-term outcome of two types of total wrist arthroplasty (TWA) in terms of wrist function, migration, and periprosthetic bone behaviour. Methods. A total of 40 patients suffering from non-rheumatoid wrist arthritis were enrolled in a randomized controlled trial comparing the ReMotion and Motec TWAs. Patient-rated and functional outcomes, radiological changes, blood metal ion levels, migration measured by model-based radiostereometric analysis (RSA), bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), complications, loosening, and revision rates at two years were compared. Results. Patient-Rated Wrist and Hand Evaluation (PRWHE) scores, abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) scores, and pain improved similarly and significantly in both groups. Wrist motion improved significantly in the Motec group only, and forearm rotation in the ReMotion group only. Cobalt (Co) and chromium (Cr) blood ion levels were significantly higher in the metal-on-metal (MoM) Motec group than in the metal-on-polyethylene (MoP) ReMotion group. Mean total translation was 0.65 mm (95% confidence interval (CI) 0.26 to 1.12) and 0.27 mm (95% CI 0.14 to 0.47) for the ReMotion carpal and radial components, and 0.32 mm (95% CI 0.22 to 0.45) and 0.26 mm (95% CI 0.20 to 0.34) for the Motec metacarpal and radial components, respectively. Apart from dorsal and volar tilts, which were significantly higher for the radial ReMotion than for the Motec component, no significant differences in absolute migration occurred. BMD around the radial components never returned to baseline. Almost one-third of patients required reoperation due to complications. Two ReMotion implants were revised to Motec TWAs due to carpal component loosening, and three Motec MoM articulations were revised to metal-on-polyether ether ketone due to painful synovitis. Conclusion. Both implants provided matched function and were stable at short-term follow-up, but with a high complication rate. This procedure should be restricted to specialist centres undertaking prospective analysis until its role is clarified. Cite this article: Bone Joint J 2022;104-B(10):1132–1141

Aims. The distal radius is a major site of osteoporotic bone loss resulting in a high risk of fragility fracture. This study evaluated the capability of a cortical index (CI) at the distal radius to predict the local bone mineral density (BMD). Methods. A total of 54 human cadaver forearms (ten singles, 22 pairs) (19 to 90 years) were systematically assessed by clinical radiograph (XR), dual-energy X-ray absorptiometry (DXA), CT, as well as high-resolution peripheral quantitative CT (HR-pQCT). Cortical bone thickness (CBT) of the distal radius was measured on XR and CT scans, and two cortical indices mean average (CBTavg) and gauge (CBTg) were determined. These cortical indices were compared to the BMD of the distal radius determined by DXA (areal BMD (aBMD)) and HR-pQCT (volumetric BMD (vBMD)). Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC) were used to compare the results and degree of reliability. Results. The CBT could accurately be determined on XRs and highly correlated to those determined on CT scans (r = 0.87 to 0.93). The CBTavg index of the XRs significantly correlated with the BMD measured by DXA (r = 0.78) and HR-pQCT (r = 0.63), as did the CBTg index with the DXA (r = 0.55) and HR-pQCT (r = 0.64) (all p < 0.001). A high correlation of the BMD and CBT was observed between paired specimens (r = 0.79 to 0.96). The intra- and inter-rater reliability was excellent (ICC 0.79 to 0.92). Conclusion. The cortical index (CBTavg) at the distal radius shows a close correlation to the local BMD. It thus can serve as an initial screening tool to estimate the local bone quality if quantitative BMD measurements are unavailable, and enhance decision-making in acute settings on fracture management or further osteoporosis screening. Cite this article: Bone Joint Res 2021;10(12):820–829

Introduction and Aims: This study evaluated the proximal femoral remodelling associated with three uncemented femoral prostheses of different designs and surface treatments. We hypothesised that less bone loss will occur over time with a titanium implant designed for proximal stress transfer compared to a more rigid stem that produces diaphyseal loading. Method: During total hip arthroplasty (THA), patients were implanted with either: AML cobalt-chrome alloy porous-coated stem (11 patients), Osteonics titanium alloy hydroxyapatite-coated stem (13 patients), or Sulzer titanium alloy hydroxyapatite-coated stem (eight patients). All patients followed the same surgical and post-surgical protocol for THA. Dual energy x-ray absorptiometry (DEXA) scans of the operated proximal femur were performed on all patients pre-operatively, three to seven days post-operatively, and then six weeks, six months, and annually up to five years post-operatively. Longitudinal changes in bone mineral density (BMD) were compared within and between the two groups. Results: Using the first post-op DEXA scan as baseline, the percent change in BMD (g/cm. 2. ) at one year was −17.06% in patients implanted with the AML stem. The percent change in BMD at one year was −3.06% in the Osteonics group and in the Sulzer group, the percent change in BMD at one year was −4.11%. The greater bone loss observed with the AML stem was found to be statistically different than the bone loss observed with the other two stems. These findings continued at three and five years post-operatively. Conclusion: There was a trend toward less bone atrophy and preservation of bone stock in patients implanted with both the HA and Sulzer stems. Extensively coated, diaphyseal-fitting, CoCr stems (AML) definitely caused greater bone loss, both proximally and in the diaphysis

Purpose: Bone remodelling and osteolysis around total hip arthroplasty (THA) is a highly debated subject in the medical literature. Such bone behaviour is poorly understood around femoral stems used in revision THA. The main problem is to obtain an objective assessment of bone remodelling and bone reconstruction over time, reconstruction techniques being very variable. Conventional radiology is insufficient, but dual energy x-ray absorptiometry (DEXA) provides a means of following changes in the bone around first intention femoral stems. Material and methods: We studied bone behaviour around revision femoral stems using the non-cemented “P.P. system”. This type of femoral stem is implanted after trochanter osteotomy to facilitate access and stimulate reconstruction. The series included 31 patients who underwent revision total hip arthroplasty. Follow-up examinations included standard radiographs and DEXA of the operated hips, the contralateral hip and the lumbar spine. Periprosthetic zones defined by Grüen were compared with the same zones in the contra-lateral femur. Mean follow-up was six years. Results: The standard radiographs did not demonstrate any significant change in periprosthetic cortical thickness. The DEXA demonstrated a significant an average 19.97% reduction in bone density in zones 2, 3, 4, 5 and 6. There was no significant difference in zone 7 and an increase in zone 1 (torchanter osteotomy). These figures are to be compared with the variable thickness observed for first intention pros-theses even shortly after implantation. Discussion: Our results are the first to our knowledge demonstrating the behaviour of bone around revision femoral stems. Conclusion: Digastric trochanterotomy appears to be an effective means of stimulating reconstruction of the proximal femur. At equivalent follow-up, the quadrangular section of the revision P.P. stem is more favourable in terms of bone loss compared with first intention stems

The measurement of bone mineral density in defined areas around metal implants has improved with the development of dual-energy X-ray absorptiometry. We used this technique to compare the bone mineral density adjacent to metal cementless femoral implants with that of identical regions of bone in normal proximal femora. We studied the anteroposterior views only of 72 femora which contained total hip implants and 34 non-operated femora. We compared the regional bone mineral density of bone adjacent to proximally porous-coated and distally porous-coated implants of one design, to measure the relative differences in the remodelling changes induced by different amounts of porous coating. We also measured differences in bone density with time and with variations in implant size (and therefore stiffness). The greatest decrease in bone mineral density (34.8%) occurred in the most proximal 1 cm of the medial femoral cortex around relatively stiff, extensively porous-coated implants. The next most severe decrease (20% to 25%) was in the next most proximal 6 cm of the medial femoral cortex. Small, progressive decreases in bone mineral density continued for five to seven years after implantation

Aim: To compare the difference in periprosthetic bone density between cemented and uncemented total hip replacement at a minimum follow up of 10 years. Patients and methods: We looked at a cohort of 17 patients who have had bilateral total hip replacement with cemented Charnley total hip on one side and uncemented Furlong total hip on the other side between 1984 and 1994 (minimum follow up 10 years). Harris and Oxford hip scores were used to determine the function, SF 36 was used to measure quality of life and Dual energy X-Ray absorptiometry (DEXA) scan was used to quantify bone mineral density adjacent to the prosthesis. The results from the DEXA scan for cemented and the uncemented hips were analysed using Paired samples two tailed t-tests. To compare the Harris hip scores, a non-parametric Wilcoxon test was used. Pearson correlations were carried out to examine the relationship between the bone density measures (averaged for each zone) and the quality of life measures. Results: Bone mineral density was higher on the Furlong side in Gruen Zones 2, 3, 5 and 6 of the proximal femur and DeLee Charnley Zone 1 of the acetabulum. In all other zones there was no statistical difference. Comparison of Harris hip scores and Oxford hip scores showed no statistically significant difference between the two hips (p = 0.108). Age is negatively correlated with bone density in Gruen zones 6 and 7 and acetabular zones 2 and 3. Conclusion: Bone density is better preserved around the uncemented HAC coated stem compared to the Charnley cemented stem

Introduction: Dual-energy x-ray absorptiometry (DEXA) measurement is a valuable and accurate method of assessing periprosthetic bone loss around femoral stems. Method: The cohort was 21 patients who underwent total hip arthroplasties with double-threaded, cone-shaped, modular, femoral stems and who already had a prosthetic contralateral hip. The contralateral hip arthroplasties were Autophur fully porous coated, Exeter cemented and Charnley cemented stems. DEXA measurements were performed in the anteroposterior femoral plane using a Lunar DPXL densitometer and analysed using the Lunar Orthopaedic Software Package, Version 1.7, designed for periprosthetic measurements. The initial measurement was performed between two and four weeks after the surgery as a baseline and then repeated after three, six, 12 and 24 months. The DEXA scan results were analysed comparing the bone density of the double-threaded cone-shaped modular femoral stem side with the contralateral side in a longitudinal study. Results: The contralateral hip bone quality remained fairly constant in keeping with the maturity of the hip arthroplasties. The insertion of the double-threaded cone-shaped modular femoral stem caused the expected initial bone loss in Gruen zones one and seven due to proximal stress-shielding. Only minor bone loss occurred distally, reflecting good fixation and load transfer of the prosthesis

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?

Introduction

Aseptic loosening is the main reason for total knee arthroplasty (TKA) failure, responsible for more than 25% of the revision procedures, with most of the problems occurring with the tibial component. While early loosening can be attributed to failure of primary fixation, late implant loosening is associated with loss of fixation secondary to bone resorption due to altered physiological load transfer to the tibial bone. Several attempts have been made to investigate these changes in bone load transfer in biomechanical simulations and bone remodeling analyses, which can be useful to provide information on the effect of patient, surgery, or design-related factors. On the other hand, these factors have also been investigated in clinical studies of radiographic changes of bone density following TKA. In this study we made an overview of the knowledge obtained from these clinical studies, which can be used to inform clinical decision making and implant design choices.

Purpose: With appropriate software, dual energy x-ray absorptiometry (DEXA) provides a means of measuring periprosthetic bone mineral density (BMD) reliably and reproducibly in a single plane. The current method has been improved since the first reports by MacCarthy in 1991. Material and methods: Since 1992, two series of total hip arthroplasty femoral prostheses using a ceramic-polyethylene cup with a TA6V4 stem were implanted with cement (group A 25 SAS crystal anatomic stems, 22.2 head) or without cement (group B, 27 Euroform stems with hydroxyapatite surfacing on the upper 2/5, 28 head). The patients were followed prospectively with DEXA to measure BMD in the seven Gruen zones immediately after surgery, at six and twelve months, then every year to last follow-up. Mean follow-up was 74 months (36–166). A visual analogue scale was used for subjective assessment of pain. The clinical Harris score and radiological findings were also recorded. Results: At last follow-up none of the prostheses had required revision surgery. The Harris score was greater than 90 for both groups (mean 91.4 and 95.4 for groups A and B respectively). Radiologically, there were no progressive lucent lines in the two groups but there were three stable lines (zone V, VII, VII, II) without clinical expression in group A and two (zone II, I) with persistent thigh pain in group B. Two migrations of less than 3 mm were also found in group A and four of more than 3 mm in group B. For the two groups, DEXA showed a diffuse reduction in BMD during the first six months that was statistically significant only for zones I and VII for the Euroform implant and for zone VII for the SAS Crystal implant. There was also a significant difference between the two prostheses for zone I. Modifications were not significant at three years and a last follow-up for the distal regions (II, II, V, VI). For group A (SAS Crystal), the reduction was 5.8% at three years and 5.7% at last follow-up for zone I and 18% at three years and 19% at last follow-up for zone VII. For group B, the reduction was 12.6 at three years and 11.4% at last follow-up for zone I and 17.4% at three years and 21.3% at last follow-up for zone VII. Discussion: The correlations showed that variations in BMD were independent of the initial bone mineral content, patient age or sex, and were not significantly different between the two cemented or non-cemented implants. Patients with painful thighs (two in group A and six in group B) had a different pattern of BMD over time, showing less pronounced reduction in the proximal zones I and VII and marked bone resorption in zones III and V, an expression of different stress transmission. Conclusion: This study provided the longest longitudinal radiological and clinical follow-up reported in the literature which, despite the bias introduced by the different types of implants, shows the reliability and reproducibility of DEXA of periprosthetic bone mineral density used to assess implant tolerance and quality of cementing

Introduction: There is limited literature looking into the circumstances surrounding the development of stress fractures of the medial and lateral malleoli after ankle replacement. We present the preliminary results of a prospective study examining the effect of total ankle replacement (TAR) upon local bone mineral density (BMD) and the phenomenon of stress shielding.

Aim: To assess the effect of TAR loading othe medial and lateral malleoli, by analysing the BMD of the medial and lateral malleoli before and after Mobility TAR.

Methodology: Ten consecutive patients undergoing Mobility total ankle replacement for osteoarthritis had pre-operative bone densitometry scans of the ankle, repeated at 6 and 12 months after surgery. The bone mineral density of a 2 cm square area within the medial and lateral malleoli was measured. The pre-operative and post-operative bone densitometry scans were compared. The relation between the alignment of the tibial component and the bone mineral density of the malleoli was also analysed.

Results: The mean preoperative BMD within the medial malleolus increased from a mean of 0.57g/cm2 to 0.58g/cm2 at six months and 0.60g/cm2 at 12 months postoperatively. The mean preoperative BMD within the lateral malleolus decreased from 0.39g/cm2 to 0.34g/cm2 at six months postoperatively. However the BMD over the lateral malleolus increased to 0.356g/cm2 at 12 months. The mean alignment of the tibial component was 88.50 varus (range 850 varus to 940 valgus). There was no correlation between the alignment of the tibial component and the bone mineral density on the medial malleolus (r = 0.09, p = 0.865).

Conclusion: The absence of stress shielding around the medial malleolus indicates that ankle replacements implanted within the accepted limits for implant alignment, load the medial malleolus. However, there was stress shielding over the lateral malleolus resulting in decreased BMD in the lateral malleolus.

Aims

Previous studies have suggested that selenium as a trace element is involved in bone health, but findings related to the specific effect of selenium on bone health remain inconclusive. Thus, we performed a meta-analysis by including all the relevant studies to elucidate the association between selenium status (dietary intake or serum selenium) and bone health indicators (bone mineral density (BMD), osteoporosis (OP), or fracture).

Aims. The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems. Methods. In this case-control study, 25 patients (22 female) at mean age of 78 years (70 to 89) received cemented Exeter short stem (case group). Cases were selected based on Dorr type A femora and matched first by Dorr type A and then age to a control cohort of 21 patients (11 female) at mean age of 74 years (70 to 89) who received with cemented Exeter standard stems (control group). Preoperatively, all patients had primary hip osteoarthritis and no osteoporosis as confirmed by dual X-ray absorptiometry scanning. Patients were followed with radiostereometry for evaluation of stem migration (primary endpoint), evaluation of cement quality, and Oxford Hip Score. Measurements were taken preoperatively, and at three, 12, and 24 months and a minimum five-year follow-up. Results. At three months, subsidence of the short stem -0.87 mm (95% confidence interval (CI) -1.07 to -0.67) was lower compared to the standard stem -1.59 mm (95% CI -1.82 to -1.36; p < 0.001). Both stems continued a similar pattern of subsidence until five-year follow-up. At five-year follow-up, the short stem had subsided mean -1.67 mm (95% CI -1.98 to -1.36) compared to mean -2.67 mm (95% CI -3.03 to -2.32) for the standard stem (p < 0.001). Subsidence was not influenced by preoperative bone quality (osteopenia vs normal) or cement mantle thickness. Conclusion. The standard Exeter stem had more early subsidence compared with the short Exeter stem in patients with Dorr type A femora, but thereafter a similar migration pattern of subsidence until minimum five years follow-up. Both the standard and the short Exeter stems subside. The standard stem subsides more compared to the short stem in Dorr type A femurs. Subsidence of the Exeter stems was not affected by cement mantle thickness. Cite this article: Bone Jt Open 2023;4(7):507–515

Aims. The association of auraptene (AUR), a 7-geranyloxycoumarin, on osteoporosis and its potential pathway was predicted by network pharmacology and confirmed in experimental osteoporotic mice. Methods. The network of AUR was constructed and a potential pathway predicted by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) terms enrichment. Female ovariectomized (OVX) Institute of Cancer Research mice were intraperitoneally injected with 0.01, 0.1, and 1 mM AUR for four weeks. The bone mineral density (BMD) level was measured by dual-energy X-ray absorptiometry. The bone microstructure was determined by histomorphological changes in the femora. In addition, biochemical analysis of the serum and assessment of the messenger RNA (mRNA) levels of osteoclastic markers were performed. Results. In total, 65.93% of the genes of the AUR network matched with osteoporosis-related genes. Osteoclast differentiation was predicted to be a potential pathway of AUR in osteoporosis. Based on the network pharmacology, the BMD and bone mineral content levels were significantly (p < 0.05) increased in the whole body, femur, tibia, and lumbar spine by AUR. AUR normalized the bone microstructure and the serum alkaline phosphatase (ALP), bone-specific alkaline phosphatase (bALP), osteocalcin, and calcium in comparison with the OVX group. In addition, AUR treatment reduced TRAP-positive osteoclasts and receptor activator of nuclear factor kappa-B ligand (RANKL). +. nuclear factor of activated T cells 1 (NFATc1). +. expression in the femoral body. Moreover, the expressions of initiators for osteoclastic resorption and bone matrix degradation were significantly (p < 0.05) regulated by AUR in the lumbar spine of the osteoporotic mice. Conclusion. AUR ameliorated bone loss by downregulating the RANKL/NFATc1 pathway, resulting in improvement of osteoporosis. In conclusion, AUR might be an ameliorative cure that alleviates bone loss in osteoporosis via inhibition of osteoclastic activity. Cite this article: Bone Joint Res 2022;11(5):304–316

Objectives. Experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) may have negative effects on fracture healing. This study aimed to assess the effect of immediate and delayed short-term administration of clinically relevant parecoxib doses and timing on fracture healing using an established animal fracture model. Methods. A standardized closed tibia shaft fracture was induced and stabilized by reamed intramedullary nailing in 66 Wistar rats. A ‘parecoxib immediate’ (Pi) group received parecoxib (3.2 mg/kg bodyweight twice per day) on days 0, 1, and 2. A ‘parecoxib delayed’ (Pd) group received the same dose of parecoxib on days 3, 4, and 5. A control group received saline only. Fracture healing was evaluated by biomechanical tests, histomorphometry, and dual-energy x-ray absorptiometry (DXA) at four weeks. Results. For ultimate bending moment, the median ratio between fractured and non-fractured tibia was 0.61 (interquartile range (IQR) 0.45 to 0.82) in the Pi group, 0.44 (IQR 0.42 to 0.52) in the Pd group, and 0.50 (IQR 0.41 to 0.75) in the control group (n = 44; p = 0.068). There were no differences between the groups for stiffness, energy, deflection, callus diameter, DXA measurements (n = 64), histomorphometrically osteoid/bone ratio, or callus area (n = 20). Conclusion. This study demonstrates no negative effect of immediate or delayed short-term administration of parecoxib on diaphyseal fracture healing in rats. Cite this article: G. A. Hjorthaug, E. Søreide, L. Nordsletten, J. E. Madsen, F. P. Reinholt, S. Niratisairak, S. Dimmen. Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model. Bone Joint Res 2019;8:472–480. DOI: 10.1302/2046-3758.810.BJR-2018-0341.R1

Osteoporosis is a common disorder characterized by low bone mass and reduced bone quality that affects the bone strength negatively and leads to increased risk of fracture. Bone mineral density (BMD) has been the standard instrument for the diagnosis of osteoporosis and the determination of fracture risk. Despite the approximation of the bone mass, BMD does not provide information about the bone structure. Trabecular bone score (TBS), which provides an indirect evaluation of skeletal microarchitecture, is calculated from dual X-ray absorptiometry and a simple and noninvasive method that may contribute to the prediction of osteoporotic fractures in addition to the measure of bone density. The goal of this study was to determine the mean TBS values in healthy postmenopausal women and the overall association between TBS and demographic features, bone mineral density of the lumbar spine and femoral neck and bone mineral density to body mass index ratio (BMD/BMI) of the lumbar spine. Fifty-three postmenopausal healthy women participated. The bone mineral density of the lumbar spine and femoral neck were measured dual X-ray absorptiometry. Anteroposterior lumbar spine acquisitions were used to calculate TBS for L1-L4. Age, height, weight, BMI and the ratio of BMD to BMI, which was considered to be a simple tool for assessing fracture risk in especially obese individuals, were calculated. The relationship between TBS and other variables was examined using Spearman's rank correlation coefficients. Mean BMD of the lumbar spine and the femoral neck were 0.945 ± 0.133 and 0.785 ± 0.112 g/cm2, respectively (Table 1). Mean TBS was 1.354 ± 0.107. There was a significant positive moderate correlation between TBS and total lumbar BMD/BMI ratio (r=0.595, pTBS values of postmenopausal women were negatively correlated with age and BMI and positively with bone mineral density and BMD/BMI ratio. The ratio between lumbar BMD and BMI presented a stronger correlation with TBS than that of BMD with TBS. Because of the better correlation, the BMD/BMI ratio may be used as a simple tool for the assessment of the risk of fractures. Further investigation may be needed to evaluate the factors influencing exercise intervention on TBS on this population of patients

Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMD. 119 patients were randomized to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years comparing the unoperated contralateral femur as a control. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% in the mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. Implant design was shown to impact BMD changes. All stems preserved bone at the metaphyseal level in early follow-up, which theoretically indicates favorable implant fixation. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship

Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMDMethods: 119 patients were randomised to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. All surgeries were performed via the posterior approach with mobilization on the day of surgery. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years and compared to the unoperated contralateral femur as a control. Patient reported outcome measures of pain, function and health were also included at these corresponding follow-ups. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% inthe mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. This study demonstrated maintenance of femoral BMD in three different cementless femoral stem designs, with all achieving excellent improvements in patient reported outcomes. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship

Aims. Uncemented metal acetabular components show good osseointegration, but material stiffness causes stress shielding and retroacetabular bone loss. Cemented monoblock polyethylene components load more physiologically; however, the cement bone interface can suffer fibrous encapsulation and loosening. It was hypothesized that an uncemented titanium-sintered monoblock polyethylene component may offer the optimum combination of osseointegration and anatomical loading. Methods. A total of 38 patients were prospectively enrolled and received an uncemented monoblock polyethylene acetabular (pressfit) component. This single cohort was then retrospectively compared with previously reported randomized cohorts of cemented monoblock (cemented) and trabecular metal (trabecular) acetabular implants. The primary outcome measure was periprosthetic bone density using dual-energy x-ray absorptiometry over two years. Secondary outcomes included radiological and clinical analysis. Results. Although there were differences in the number of males and females in each group, no significant sex bias was noted (p = 0.080). Furthermore, there was no significant difference in age (p = 0.910) or baseline lumbar bone mineral density (BMD) (p = 0.998) found between any of the groups (pressfit, cemented, or trabecular). The pressfit implant initially behaved like the trabecular component with an immediate fall in BMD in the inferior and medial regions, with preserved BMD laterally, suggesting lateral rim loading. However, the pressfit component subsequently showed a reversal in BMD medially with recovery back towards baseline, and a continued rise in lateral BMD. This would suggest that the pressfit component begins to reload the medial bone over time, more akin to the cemented component. Analysis of postoperative radiographs revealed no pressfit component subsidence or movement up to two years postoperatively (100% interobserver reliability). Medial defects seen immediately postoperatively in five cases had completely resolved by two years in four patients. Conclusion. Initially, the uncemented monoblock component behaved similarly to the rigid trabecular metal component with lateral rim loading; however, over two years this changed to more closely resemble the loading pattern of a cemented polyethylene component with increasing medial pelvic loading. This indicates that the uncemented monoblock acetabular component may result in optimized fixation and preservation of retroacetabular bone stock. Cite this article: Bone Joint J 2021;103-B(5):872–880

Aims. Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. Methods. This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m. 2. , and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (μg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported. Results. A total of 43 patients were enrolled. At minimum follow-up of five years, 23 (53.4%) returned for clinical and radiological review, 25 (58.1%) had metal ion analysis performed, 19 (44.2%) underwent dual energy x-ray absorptiometry scans, and 25 (58%) completed a pain-drawing questionnaire. The mean modified Harris Hip Scores improved significantly from 54.8 (SD 19) preoperatively to 93.08 (SD 10.5) five years postoperatively (p < 0.001). One patient was revised for aseptic acetabular loosening. The mean cobalt levels increased from 0.065 μg/l (SD 0.03) to 0.08 (SD 0.05) and the mean titanium levels increased from 0.35 (SD 0.13) to 0.78 (SD 0.29). The femoral BMD ratio decreased in Gruen Zone 1 (91.9%) at five years postoperatively compared with the baseline scores at six weeks potoperatively. The femoral BMD ratio was maintained in Gruen zones 2 to 7. Conclusion. The use of a modular DM component and a cementless, tapered femoral stem shows excellent mid-term survivorship with minimal concerns for corrosion and metal ion release in a cohort of young, active patients undergoing primary THA. Cite this article: Bone Joint J 2021;103-B(7 Supple B):73–77

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

Objectives. The aim of the current study was to assess whether calcaneal broadband ultrasound attenuation (BUA) can predict whole body and regional dual-energy x-ray absorptiometry (DXA)-derived bone mass in healthy, Australian children and adolescents at different stages of maturity. Methods. A total of 389 boys and girls across a wide age range (four to 18 years) volunteered to participate. The estimated age of peak height velocity (APHV) was used to classify children into pre-, peri-, and post-APHV groups. BUA was measured at the non-dominant heel with quantitative ultrasonometry (QUS) (Lunar Achilles Insight, GE), while bone mineral density (BMD) and bone mineral content (BMC) were examined at the femoral neck, lumbar spine and whole body (DXA, XR-800, Norland). Associations between BUA and DXA-derived measures were examined with Pearson correlations and linear regression. Participants were additionally ranked in quartiles for QUS and DXA measures in order to determine agreement in rankings. Results. For the whole sample, BUA predicted 29% of the study population variance in whole body BMC and BMD, 23% to 24% of the study population variance in lumbar spine BMC and BMD, and 21% to 24% of the variance in femoral neck BMC and BMD (p < 0.001). BUA predictions were strongest for the most mature participants (pre-APHV R. 2. = 0.03 to 0.19; peri-APHV R. 2. = 0.05 to 0.17; post-APHV R. 2. = 0.18 to 0.28) and marginally stronger for girls (R. 2. = 0.25-0.32, p < 0.001) than for boys (R. 2. = 0.21-0.27, p < 0.001). Agreement in quartile rankings between QUS and DXA measures of bone mass was generally poor (27.3% to 38.2%). Conclusion. Calcaneal BUA has a weak to moderate relationship with DXA measurements of bone mass in children, and has a tendency to misclassify children on the basis of quartile rankings. Cite this article: B. K. Weeks, R. Hirsch, R. C. Nogueira, B. R. Beck. Is calcaneal broadband ultrasound attenuation a valid index of dual-energy x-ray absorptiometry-derived bone mass in children? Bone Joint Res 2016;5:538–543. DOI: 10.1302/2046-3758.511.BJR-2016-0116.R1

Aims. Idiopathic scoliosis is the most common spinal deformity in adolescents and children. The aetiology of the disease remains unknown. Previous studies have shown a lower bone mineral density in individuals with idiopathic scoliosis, which may contribute to the causation. The aim of the present study was to compare bone health in adolescents with idiopathic scoliosis with controls. Methods. We included 78 adolescents with idiopathic scoliosis (57 female patients) at a mean age of 13.7 years (8.5 to 19.6) and 52 age- and sex-matched healthy controls (39 female patients) at a mean age of 13.8 years (9.1 to 17.6). Mean skeletal age, estimated according to the Tanner-Whitehouse 3 system (TW3), was 13.4 years (7.4 to 17.8) for those with idiopathic scoliosis, and 13.1 years (7.4 to 16.5) for the controls. Mean Cobb angle for those with idiopathic scoliosis was 29° (SD 11°). All individuals were scanned with dual energy x-ray absorptiometry (DXA) and peripheral quantitative CT (pQCT) of the left radius and tibia to assess bone density. Statistical analyses were performed with independent-samples t-test, the Mann-Whitney U test, and the chi-squared test. Results. Compared with controls, adolescents with idiopathic scoliosis had mean lower DXA values in the left femoral neck (0.94 g/cm. 2. (SD 0.14) vs 1.00 g/cm. 2. (SD 0.15)), left total hip (0.94 g/cm. 2. (SD 0.14) vs 1.01 g/cm. 2. (SD 0.17)), L1 to L4 (0.99 g/cm. 2. (SD 0.15) vs 1.06 g/cm. 2. (SD 0.17)) and distal radius (0.35 g/cm. 2. (SD 0.07) vs 0.39 g/cm. 2. (SD 0.08; all p ≤ 0.024), but not in the mid-radius (0.72 g/cm. 2. vs 0.74 g/cm. 2. ; p = 0.198, independent t-test) and total body less head (1,559 g (SD 380) vs 1,649 g (SD 492; p = 0.0.247, independent t-test). Compared with controls, adolescents with idiopathic scoliosis had lower trabecular volume bone mineral density (BMD) on pQCT in the distal radius (184.7 mg/cm. 3. (SD 40.0) vs 201.7 mg/cm. 3. (SD 46.8); p = 0.029), but not in other parts of the radius or the tibia (p ≥ 0.062, Mann-Whitney U test). Conclusion. In the present study, idiopathic scoliosis patients seemed to have lower BMD at central skeletal sites and less evident differences at peripheral skeletal sites when compared with controls. Cite this article: Bone Joint J 2020;102-B(2):268–272

Introduction and Objective. Geriatric patients with a fragility fracture of the hip (FFH) are especially prone to sarcopenia with poor functional outcomes and quality of life. We assessed the prevalence of sarcopenia in older South African patients with FFH. Risk factors for sarcopenia were also investigated. Materials and Methods. From August 1 to November 30, 2018, all older patients with FFH were invited to participate. Sarcopenia was diagnosed based on the revised criteria of the European Working Group on Sarcopenia in Older People (EWGSOP2). Handgrip strength (HGS) and muscle strength were assessed. Muscle quantity was determined by dual-energy X-ray absorptiometry. Demographic information was collected, and 25-hydroxyvitamin D (25[OH]D) status was determined. Results. Of the 100 hip fracture cases, 65 were enrolled, and 52% (34/65) were sarcopenic (women: 62%; men: 38%). HGS accurately identified sarcopenia (sensitivity and specificity: 100%). Patients >80 years of age had a prevalence of sarcopenia twice (18/21 [83%]) that of younger patients (18/44 [36%]). Women with sarcopenia were smaller than those without (weight: p < 0.001; height: p < 0.001; body mass index: p¼0.018). Low 25(OH)D was almost universally present, with median 25(OH)D levels significantly lower in the patients with sarcopenia (27 nmol/L [interquartile range {IQR}: 20–39] vs. 40 nmol/L [IQR: 29–53]). Several risk factors, including advanced age; female sex; a smaller body size, especially among women; limited physical activity; and low 25(OH)D levels, were identified. Conclusions. The accuracy of HGS testing in this cohort underscores EWGSOP2's recommendation that muscle strength is key to sarcopenia. Further study and follow-up are required to determine the clinical relevance of sarcopenia among FFH patients. The prevalence of sarcopenia in our FFH population is high. Sarcopenia is associated with poor patient outcomes following surgical intervention. Orthopaedic surgeons should therefore be cognisant of the presentation and associated risk of sarcopenia as our patient populations age

Hip fractures are associated with poor outcomes and high mortality rates of 30%. The current gold standard to measure bone fragility is a Dual-Energy X-ray Absorptiometry (DEXA) scan measuring bone mineral density. Yet DEXA under-diagnoses bone fragility by 50% (1). To combat the burden of bone fragility, this experimental study combined ultrasound (US) with a sophisticated computational algorithm, namely full wave inversion (FWI), to evaluate femoral bone structure. The aims were to assess the association of bone structure between the proximal femoral diaphysis and femoral neck; secondly to evaluate whether transverse ultrasound could assess bone structure of the proximal femoral diaphysis. Bone structure of 19 ex vivo human femora was assessed by micro-CT analysis (mean age 88.11 years, male:female 13:6)(Nikon HMXST 225). Using ImageJ/BoneJ, three 10.2mm subsections of proximal diaphysis and femoral neck underwent analysis: the total bone volume fraction, cortical parameters (bone volume fraction, porosity, thickness) and trabecular parameters (porosity, thickness, spacing and connectivity). A unique US prototype was developed to analyse fifteen femoral diaphyseal subsections using two P4-1 transducers with a novel tomography sequence (Verasonics, Matlab ver R2019a, FWI TRUST protocol). Comparative quantitative analysis of US and Micro-CT measurements was assessed (Graphpad Prism 8.3.1). Micro-CT analysis of the proximal femoral diaphysis demonstrated low correlation to the femoral neck (Pearson r −0.54 to 0.55). US was able to capture cortical structure, though a wide limit of agreement seen when compared to micro-CT analysis (Bland-Altman range 36–59% difference). This novel US technique was able to capture cortical bone structure. Improvements in methodology and technology are required to improve the analysis of trabecular bone and overall accuracy. Further evaluation of US and FWI is required to develop the technique and determine its role in clinical practice

Objectives. Researchers continue to seek easier ways to evaluate the quality of bone and screen for osteoporosis and osteopenia. Until recently, radiographic images of various parts of the body, except the distal femur, have been reappraised in the light of dual-energy X-ray absorptiometry (DXA) findings. The incidence of osteoporotic fractures around the knee joint in the elderly continues to increase. The aim of this study was to propose two new radiographic parameters of the distal femur for the assessment of bone quality. Methods. Anteroposterior radiographs of the knee and bone mineral density (BMD) and T-scores from DXA scans of 361 healthy patients were prospectively analyzed. The mean cortical bone thickness (CBTavg) and the distal femoral cortex index (DFCI) were the two parameters that were proposed and measured. Intra- and interobserver reliabilities were assessed. Correlations between the BMD and T-score and these parameters were investigated and their value in the diagnosis of osteoporosis and osteopenia was evaluated. Results. The DFCI, as a ratio, had higher reliability than the CBTavg. Both showed significant correlation with BMD and T-score. When compared with DFCI, CBTavg showed better correlation and was better for predicting osteoporosis and osteopenia. Conclusion. The CBTavg and DFCI are simple and reliable screening tools for the prediction of osteoporosis and osteopenia. The CBTavg is more accurate but the DFCI is easier to use in clinical practice. Cite this article: Q-F. He, H. Sun, L-Y. Shu, Y. Zhu, X-T. Xie, Y. Zhan, C-F. Luo. Radiographic predictors for bone mineral loss: Cortical thickness and index of the distal femur. Bone Joint Res 2018;7:468–475. DOI: 10.1302/2046-3758.77.BJR-2017-0332.R1

Objectives. The goal of this study is to investigate the relation between indicators of osteoporosis (i.e., bone mineral density (BMD), and Cortical Index (CI)) and the complexity of a fracture of the proximal humerus as a result of a low-energy trauma. Methods. A retrospective chart review of 168 patients (mean age 67.2 years, range 51 to 88.7) with a fracture of the proximal humerus between 2007 and 2011, whose BMD was assessed at the Fracture Liaison Service with Dual Energy X-ray Absorptiometry (DXA) measurements of the hip, femoral neck (FN) and/or lumbar spine (LS), and whose CI and complexity of fracture were assessed on plain anteroposterior radiographs of the proximal humerus. Results. No significant differences were found between simple and complex fractures of the proximal humerus in the BMD of the hip, FN or LS (all p > 0.3) or in the CI (p = 0.14). Only the body mass index was significantly higher in patients with a complex fracture compared with those with a simple fracture (26.9 vs 25.2; p = 0.05). Conclusion. There was no difference in BMD of the hip, FN, LS or CI of the proximal humerus in simple compared with complex fractures of the proximal humerus after a low-energy trauma. Factors other than the BMD and CI, for example body mass index, may play a more important role in the complexity of this fracture. Cite this article: J.W.A.M. den Teuling, B.S. Pauwels, L. Janssen, C.E. Wyers, H. M. J. Janzing, J.P.W. van den Bergh, J. W. Morrenhof. The Influence of bone mineral density and cortical index on the complexity of fractures of the proximal humerus. Bone Joint Res 2017;6:584–589. DOI: 10.1302/2046-3758.610.BJR-2017-0080

The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum

Background. Although there are predictive equations that estimate the total fat mass obtained from multiple-site ultrasound (US) measurements, the predictive equation of total fat mass has not been investigated solely from abdominal subcutaneous fat thickness. Therefore, the aims of this study were; (1) to develop regression-based prediction equations based on abdominal subcutaneous fat thickness for predicting fat mass in young- and middle-aged adults, and (2) to investigate the validity of these equations to be developed. Methods. The study was approved by the Local Research Ethics Committee (Decision number: GO 19/788). Twenty-seven males (30.3 ± 8.7 years) and eighteen females (32.4 ± 9.5 years) were randomly divided into two groups as the model prediction group (19 males and 12 females) and the validation group (8 males and 6 females). Total body fat mass was determined by dual-energy X-ray absorptiometry (DXA). Abdominal subcutaneous fat thickness was measured by US. The predictive equations for total fat mass from US were determined as fat thickness (in mm) × standing height (in m). Statistical analyses were performed using R version 4.0.0. The association between the total fat mass and the abdominal subcutaneous fat thickness was interpreted using the Pearson test. The linear regression analysis was used to predict equations for total body fat mass from the abdominal subcutaneous fat thickness acquired by US. Then these predictive equations were applied to the validation group. The paired t-test was used to examine the difference between the measured and the predicted fat masses, and Lin's concordance correlation coefficient (CCC) was used as a further measure of agreement. Results. There was a significant positive moderate correlation between the total fat mass and the abdominal subcutaneous fat thickness × height in the model prediction group of males (r = 0.588, p = 0.008), whereas significant positive very strong correlation was observed in the model prediction group of females (r = 0.896, p < 0.001). Predictive equations for DXA-measured total body fat mass from abdominal subcutaneous fat thickness using US were as follows: for males “Fat mass-DXA = 0.276 × (Fat thickness-US × Height) + 17.221” (R. 2. = 0.35, SEE = 3.6, p = 0.008); for females “Fat mass-DXA = 0.694 x (Fat thickness-US × Height) + 7.085” (R. 2. = 0.80, SEE = 2.8, p < 0.001). When fat mass prediction equations were applied to the validation groups, measured- and estimated-total fat masses in males and females were found similar (p = 0.9, p = 0.5, respectively). A good level of agreement between measurements in males and females was attained (CCC = 0.84, CCC = 0.76, respectively). Conclusion. We developed and validated prediction equations that are convenient for determining total fat masses in young- and middle-aged adults using abdominal subcutaneous fat thickness obtained from the US. The abdominal subcutaneous fat thickness obtained from a single region by US might provide a noninvasive quick and easy evaluation not only in clinical settings but also on the field

Introduction. Bone mineral density (BMD) is correlated with component migration and aseptic loosening after total knee arthroplasty (TKA). Older implant designs have demonstrated BMD loss up to 23% in the first 6 months after TKA, and continued to BMD decline at an average of 5% per year for as long as 2 years after TKA. The impact of component design and fixation method on BMD loss after TKA in modern implant designs has not been fully elucidated. The purpose of this study is to determine the effect of tibial tray thickness and fixation method (cemented versus cementless) on BMD loss patterns of the proximal tibia in two different modern TKA implant systems. Methods. A prospective, nonrandomized, single center study of patients undergoing primary TKA by one of two surgeons was performed with four study cohorts: cemented DePuy Attune, cementless DePuy Attune, cemented Stryker Triathlon, cementless Stryker Triathlon. Target sample size was 80, with 20 per cohort based on adhoc power analysis. Exclusion criteria included: age over 75, BMI >40, inflammatory arthritis, previous knee surgery involving the femur, tibia or tibial bone, and diagnosis of osteopenia/osteoporosis. Implant fixation type was based on surgeon intraoperative assessment of patient bone quality. Demographic data was collected preoperatively. Dual Energy X-ray Absorptiometry (DEXA) Bone Density Monitoring was performed at 6 weeks and one year postoperatively. Bone mineral density was calculated from the DEXA scans for 4 zones for the tibia relative to the keel or central peg: anterior, posterior, medial and lateral. Results were reported as BMD at 1 year postoperatively as a percentage of BMD at 6 weeks postoperatively. Results. 81 knees with complete DEXA studies at 6 weeks and 1 year postoperatively were available for analysis. The mean (SD) age at the time of surgery was 65.4 years (6.1), with 39 men and 42 women and a mean (SD) BMI of 31.2 kg/m. 2. (4.7). The patients who received cementless implants were significantly younger with a mean (SD) age of 62.1 (6.0) than those who received cemented implants with a mean age of 69.1 (3.7) (p < 0.05). There was no difference in age between implant type (p > 0.05). There was no difference in BMI or gender distribution between implant types or fixation type (p > 0.05). There was no significant difference in mean BMD loss between 6 weeks and 1 year postoperatively between the cemented and cementless Triathlon in any zone, between the cemented Triathlon and Attune in any zone, the cementless Triathlon and Attune in any zone, and the cemented and cementless attune in the lateral, anterior and posterior proximal tibia (p > 0.05). There was significantly more BMD loss seen in the medial tibia in the cemented (BMD at 1 year 88% of BMD at 6 weeks) than cementless (BMD at 1 year 103% of BMD at 6 weeks) Attune (p = 0.043). Conclusion. BMD loss at 1 year postoperatively versus 6 weeks postoperatively after TKA with two modern implant designs is not significantly affected by tibial tray thickness. BMD loss was unaffected by fixation type for the Stryker Triathlon, but was significant less for the cementless DePuy Attune than the cemented version

Purpose and Background. Both overall spine shape and the size and shape of individual vertebrae undergo rapid growth and development during early childhood. Motor development milestones such as age of walking influence spine development, with delayed ambulation linked with spinal conditions including spondylolysis. However, it is unclear whether associations between motor development and spine morphology persist into older age. Therefore, these associations were examined using data from the MRC National Survey of Health and Development, a large nationally-representative British cohort, followed up since birth in 1946. Methods and Results. Statistical shape modelling was used to characterise spinal shape (L5-T10) and identify modes of variation in shape (SM) from dual energy x-ray absorptiometry images of the spine taken at age 60–64 years (N=1327 individuals; 51.8% female). Associations between walking age in months (reported by mothers at 2 years) and SMs were examined with adjustment for sex, birthweight, socioeconomic position, height, lean mass and fat mass. Later onset of independent walking was weakly associated with greater lordosis (SM1; P=0.05) and more uniform antero-posterior vertebral size along the spine (SM6, P=0.07). Later walking age was also associated with smaller relative anterior-posterior vertebral dimensions (SM3) among women whereas the opposite was found for men (P <0.01 for sex interaction). Conclusions. Spinal morphology in early old age was associated with the age that individuals began walking independently in childhood, potentially due to altered mechanical loading. This suggests that motor development may have a persisting effect on clinically-relevant features of spine morphology throughout life. Conflict of interest: None. Funded by the UK Medical Research Council (Grant MR/L010399/1) which supported FRS, SGM and AVP

Objectives. This investigation sought to advance the work published in our prior biomechanical study (Journal of Orthopaedic Research, 2016). We specifically sought to determine whether there are additional easy-to-measure parameters on plain radiographs of the proximal humerus that correlate more strongly with ultimate fracture load, and whether a parameter resembling the Dorr strength/quality characterisation of proximal femurs can be applied to humeri. Materials and Methods. A total of 33 adult humeri were used from a previous study where we quantified bone mineral density of the proximal humerus using radiographs and dual-energy x-ray absorptiometry (DEXA), and regional mean cortical thickness and cortical index using radiographs. The bones were fractured in a simulated backwards fall with the humeral head loaded at 2 mm/second via a frustum angled at 30° from the long axis of the bone. Correlations were assessed with ultimate fracture load and these new parameters: cortical index expressed in areas (“areal cortical index”) of larger regions of the diaphysis; the canal-to-calcar ratio used analogous to its application in proximal femurs; and the recently described medial cortical ratio. Results. The three new parameters showed the following correlations with ultimate fracture load: areal cortical index (r = 0.56, p < 0.001); canal-to-calcar ratio (r = 0.38, p = 0.03); and medial cortical ratio (r = 0.49, p < 0.005). These correlations were weaker when compared with those that we previously reported: mean cortical thickness of the proximal diaphysis versus ultimate fracture load (r = 0.71; p < 0.001); and mean density in the central humeral head versus ultimate fracture load (r = 0.70; p < 0.001). Conclusion. Simple-to-measure radiographic parameters of the proximal humerus reported previously are more useful in predicting ultimate fracture load than are areal cortical index, canal-to-calcar ratio, and medial cortical ratio. Cite this article: J. G. Skedros, C. S. Mears, W. Z. Burkhead. Ultimate fracture load of cadaver proximal humeri correlates more strongly with mean combined cortical thickness than with areal cortical index, DEXA density, or canal-to-calcar ratio. Bone Joint Res 2017;6:1–7. DOI: 10.1302/2046-3758.61.BJR-2016-0145.R1

Objectives. Bisphosphonates (BP) are the first-line treatment for preventing fragility fractures. However, concern regarding their efficacy is growing because bisphosphonate is associated with over-suppression of remodelling and accumulation of microcracks. While dual-energy X-ray absorptiometry (DXA) scanning may show a gain in bone density, the impact of this class of drug on mechanical properties remains unclear. We therefore sought to quantify the mechanical strength of bone treated with BP (oral alendronate), and correlate data with the microarchitecture and density of microcracks in comparison with untreated controls. Methods. Trabecular bone from hip fracture patients treated with BP (n = 10) was compared with naïve fractured (n = 14) and non-fractured controls (n = 6). Trabecular cores were synchrotron scanned and micro-CT scanned for microstructural analysis, including quantification of bone volume fraction, microarchitecture and microcracks. The specimens were then mechanically tested in compression. Results. BP bone was 28% lower in strength than untreated hip fracture bone, and 48% lower in strength than non-fractured control bone (4.6 MPa vs 6.4 MPa vs 8.9 MPa). BP-treated bone had 24% more microcracks than naïve fractured bone and 51% more than non-fractured control (8.12/cm. 2. vs 6.55/cm. 2. vs 5.25/cm. 2. ). BP and naïve fracture bone exhibited similar trabecular microarchitecture, with significantly lower bone volume fraction and connectivity than non-fractured controls. Conclusion. BP therapy had no detectable mechanical benefit in the specimens examined. Instead, its use was associated with substantially reduced bone strength. This low strength may be due to the greater accumulation of microcracks and a lack of any discernible improvement in bone volume or microarchitecture. This preliminary study suggests that the clinical impact of BP-induced microcrack accumulation may be significant. Cite this article: A. Jin, J. Cobb, U. Hansen, R. Bhattacharya, C. Reinhard, N. Vo, R. Atwood, J. Li, A. Karunaratne, C. Wiles, R. Abel. The effect of long-term bisphosphonate therapy on trabecular bone strength and microcrack density. Bone Joint Res 2017;6:602–609. DOI: 10.1302/2046-3758.610.BJR-2016-0321.R1

Aims

This study was designed to develop a model for predicting bone mineral density (BMD) loss of the femur after total hip arthroplasty (THA) using artificial intelligence (AI), and to identify factors that influence the prediction. Additionally, we virtually examined the efficacy of administration of bisphosphonate for cases with severe BMD loss based on the predictive model.

The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation. Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry. We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion

There is a disparity in sport-related injuries between sexes, with females sustaining non-contact musculoskeletal injuries at a higher rate. Anterior cruciate ligament ruptures are between two and eight times more common than in males, and females also have a higher incidence of ankle sprains, patellofemoral pain, and bone stress injuries. The sequelae of such injuries can be devastating to an athlete, resulting in time out of sport, surgery, and the early onset of osteoarthritis. It is important to identify the causes of this disparity and introduce prevention programmes to reduce the incidence of these injuries. A natural difference reflects the effect of reproductive hormones in females, which have receptors in certain musculoskeletal tissues. Relaxin increases ligamentous laxity. Oestrogen decreases the synthesis of collagen and progesterone does the opposite. Insufficient diet and intensive training can lead to menstrual irregularities, which are common in female athletes and result in injury, whereas oral contraception may have a protective effect against certain injuries. It is important for coaches, physiotherapists, nutritionists, doctors, and athletes to be aware of these issues and to implement preventive measures. This annotation explores the relationship between the menstrual cycle and orthopaedic sports injuries in pre-menopausal females, and proposes recommendations to mitigate the risk of sustaining these injuries.

Cite this article: Bone Joint J 2023;105-B(7):723–728.

SL-PLUS MIA stem (Smith & Nephew Orthopaedics AG) is a modified implant of Zweymuller type SL-PLUS standard stem (Smith & Nephew Orthopaedics AG). We constructed finite element (FE) models and analysed equivalent stresses in the femur. In addition, we measured bone mineral density (BMD) in the femur by dual-energy X-ray absorptiometry (DEXA) after THA. The purpose of this study was to investigate the equivalent stress and to compare the results of the FE analyses with changes in BMD after THA. Twenty-one patients (18 women and 3 men) who underwent primary cementless THA with SL-PLUS MIA or SL-PLUS formed the basis of this study. Eleven patients received SL-PLUS MIA and ten patients received SL-PLUS. Zones were defined according to Gruen's system (zones 1∼7). Computed-tomography (CT) images of the femur were taken before and at 1 week after THA. FE models of the femur and prosthesis were obtained from CT data by Mechanical Finder (Research Center of Computational Mechanics Inc., Tokyo, Japan), software that creates FE models showing individual bone shape and density distribution. Equivalent stresses were analysed in zones 1 to 7 and compared to the DEXA data. FE studies revealed that there was no significant difference in equivalent stress between SL-PLUS MIA and SL-PLUS. BMD was maintained after THA in zones 3, 4, and 5, whereas BMD decreased in zones 2, 6, and 7. In zone 1, BMD decreased in SL-PLUS MIA stem group by 14%, while BMD was maintained in SL-PLUS standard stem

Aims

The aim of this study was to investigate the global and local impact of fat on bone in obesity by using the diet-induced obese (DIO) mouse model.