Image-guided Percutaneous Fixation with Internal Cemented Screws of Impending Femoral Neck Pathologic Fractures in Patients with Metastatic Cancer: Safety, Efficacy, and Durability.

Background Prophylactic image-guided procedures performed by interventional radiologists for impending pathologic fractures are becoming more pertinent, as patients with metastatic cancer have extended overall survival because of advanced therapies. Purpose To evaluate the efficacy, safety, and palliative durability of collimated-beam CT-guided percutaneous fixation with internal cemented screws (FICS) for impending pathologic fractures of the femoral neck. Materials and Methods This single-institute retrospective study examined all patients with metastatic cancer treated between February 2010 and October 2019 with collimated-beam CT-guided percutaneous FICS procedures for preventive consolidation of impending femoral neck pathologic fractures. The short-term palliative efficacy was assessed through comparison of visual analog scale (VAS) scores before and 1 month after FICS. A review of cross-section imaging and clinic reports identified any procedural complications. Long-term consolidation efficacy was defined as the absence of any screw dislodgement or development of a pathologic fracture at completion of the study. The Wilcoxon test was used for the mean comparison of paired nonparametric variables. Results Sixty-one consecutive patients (mean age, 59 years ± 11 [standard deviation]; 35 women) underwent preventive FICS for consolidation of impending pathologic femoral neck fracture with a mean follow-up of 533 days ± 689. Two patients died of cancer within the first month. Complications were limited to three self-resolving hematomas. The mean VAS score decreased 1 month after FICS from 4.2 ± 3.2 to 1.8 ± 2.0 (P < .001). The long-term consolidation efficacy was 92% (54 of 59 patients), with three of 59 patients (5%) subsequently developing fractures despite FICS and an additional two of 59 patients (3%) with durable FICS undergoing definitive total hip arthroplasty surgery because of local tumor progression. Conclusion Percutaneous fixation with internal cemented screws as performed by the interventional radiologist is a safe nonsurgical treatment that provides an effective palliative result and durable prevention for impending pathologic fractures of the femoral neck. © RSNA, 2020 Online supplemental material is available for this article.

Trunk Skeletal Muscle Mass and Phase Angle Measured by Bioelectrical Impedance Analysis are Associated with the Chance of Femoral Neck Fracture in Very Elderly People.

BACKGROUND: The study aimed to investigate the potential association of trunk skeletal muscle mass (tSM) and phase angle measured by bioelectrical impedance analysis (BIA) with the chance of femoral neck fractures in very elderly people. PATIENTS AND METHODS: This case-control study enrolled 78 femoral neck fracture patients aged over 75 years (29 males) and 1:2 matched healthy controls. All participants were subjected to BIA examination by specialists. tSM, the corrected values by height squared of tSM (tSMI) and phase angle were compared between fracture patients and controls. Multivariate logistic regression was performed to explore the strength of association of femoral neck fracture with tSM, tSMI, and phase angle. RESULTS: tSM (kg) of fracture patients was significantly lower than those of controls in all participants (women: 13.49±0.42 vs 15.44±0.39, p<0.05; men: 15.30±0.71 vs 17.54±0.78, p<0.05). In the sarcopenic subgroup, fracture patients also got a lower tSM than controls (women: 12.58±0.21 vs 13.62±0.16, p<0.05; men:14.41±0.29 vs 16.07±0.21, p<0.05). The comparison of tSMI between the two groups was similar to that of tSM. Phase angle (°) at 50 kHz in fracture patients was significantly lower than that of controls in women and men (women: 3.70±0.32 vs 4.61±0.21, p<0.05; men: 3.50±0.20 vs 3.84±0.22, p<0.05). Multivariate logistic regression analysis demonstrated higher fracture chance with significantly associated decreased tSM [women: OR (95% CI): 0.78(0.67-0.91); men: 0.74(0.64-0.86)] and tSMI [women: OR (95% CI): 0.72(0.61-0.85); men: 0.69 (0.59-0.81)]. In addition, per 1° increase of phase angle in the trunk could decrease the fracture risk by 14% for women [OR (95% CI): 0.86 0.79-0.94)] and 29% for men [OR (95% CI): 0.71 (0.64-0.79)]. CONCLUSION: This study indicates a decrease in tSM, tSMI, and phase angle measured by BIA is significantly related to the increased chance of femoral neck fracture in people aged over 75 years. Strengthening the mass and strength of trunk skeletal muscles may help reduce the risk of femoral neck fracture in elderly patients.

Modelling Human Locomotion to Inform Exercise Prescription for Osteoporosis.

PURPOSE OF REVIEW: We review the literature on hip fracture mechanics and models of hip strain during exercise to postulate the exercise regimen for best promoting hip strength. RECENT FINDINGS: The superior neck is a common location for hip fracture and a relevant exercise target for osteoporosis. Current modelling studies showed that fast walking and stair ambulation, but not necessarily running, optimally load the femoral neck and therefore theoretically would mitigate the natural age-related bone decline, being easily integrated into routine daily activity. High intensity jumps and hopping have been shown to promote anabolic response by inducing high strain in the superior anterior neck. Multidirectional exercises may cause beneficial non-habitual strain patterns across the entire femoral neck. Resistance knee flexion and hip extension exercises can induce high strain in the superior neck when performed using maximal resistance loadings in the average population. Exercise can stimulate an anabolic response of the femoral neck either by causing higher than normal bone strain over the entire hip region or by causing bending of the neck and localized strain in the superior cortex. Digital technologies have enabled studying interdependences between anatomy, bone distribution, exercise, strain and metabolism and may soon enable personalized prescription of exercise for optimal hip strength.

Survival and revision causes of hip resurfacing arthroplasty and the Mitch proximal epiphyseal replacement: results from the Danish Hip Arthroplasty Register.

Background and purpose - The Mitch proximal epiphyseal replacement (PER) was developed to preserve proximal femoral bone and minimize femoral neck fracture associated with hip resurfacing arthroplasty (HRA). We studied the survival and risk of revision of HRA compared with cementless metal-on-polyethylene (MoP) total hip arthroplasty (THA) and the survival and risk of revision of the Mitch PER compared with MoP THA.Patients and methods - Using propensity score, we matched 1,057 HRA to 1,057 MoP THA and 202 Mitch PER to 1,010 MoP THA from the Danish Hip Arthroplasty Register. To estimate the relative risk (RR) of revision, we used regression with the pseudo-value approach and treated death as a competing risk.Results - The cumulative incidence for any revision of HRA at 10 years' follow-up was 11% (95% confidence interval [CI] 9.1-13) and 6.4% (CI 5.8-7.0) for MoP THA. The RR of any revision was 1.5 (CI 1.1-2.1) for HRA at 10 years' follow-up. By excluding the ASR components, the RR of revision at 10 years was 1.2 (CI 0.8-1.7). The cumulative incidence of revision was 9.6% (CI 4.2-18) for Mitch PER and 5.4% (CI 5.1-5.7) for MoP THA at 8 years. The RR of revision was 2.0 (CI 0.9-4.3) for Mitch PER at 8 years' follow-up.Interpretation - The HRA had increased risk of revision compared with the MoP THA. When excluding ASR, the HRA group had similar risk of revision compared with MoP THA. The Mitch PER did not have a statistically significant increased risk of revision compared with MoP THA.

Lower femoral neck bone mineral density (BMD) in elderly women not on statins.

Coronary artery disease (CAD) and osteoporosis, the two most frequently occurring chronic diseases of aging populations, share many risk factors including lack of estrogen, smoking, and low physical activity. CAD and low bone mineral density (BMD) are strongly associated. Statins, (3-hydroxy-3-methylglutaryl coenzyme A [HMG-CoA] reductase inhibitors), are used to prevent and treat CAD and have been associated with high BMD. This cross-sectional study examined associations of BMD with statin use and nonuse in elderly women with or without CAD. Multivariate regression analyses were conducted on 185 women aged ≥60 years who were referred between October 2010 and March 2015 to a geriatric osteoporosis clinic in Houston, Texas, for compromised skeletal health. Compared to the control group (without CAD and without statin use), patients with CAD and no statin use were more likely to have lower femoral neck BMD (ß: -0.46, 95% confidence interval: -0.75 to -0.18). The BMD of patients taking statins, regardless of presence of CAD, was similar to that of the control group. Statins may be protective in preventing bone loss in elderly women suffering from CAD. Prospective trials are warranted to determine if continued use of statins in them would help prevent both CAD and bone loss.

Conjoint Removal of Hip Screw-Femur Head during Hip Replacement after Previous Dynamic Hip Screw Fixation.

The purpose of this study was to demonstrate the reduced chances of iatrogenic femoral neck fracture while removing the Richard's screw using the dynamic hip screw-femur head conjoint removal technique. This retrospective cohort study analyzed 16 hips operated on with total hip arthroplasty from March 2010 to February 2015. All cases were previously treated with dynamic hip screws (DHS) for proximal femur fractures. The age of the patients ranged from 20 to 75 years. We used uncemented sockets in 15 patients and cemented sockets in 1 patient. We used conical fluted straight stems in 9 cases, ML (Mediolateral) tapered stems in 5 patients and CLS (Cementless Spotorno) stems in 2 patients. The head of the femur was removed together with the attached Richard's screw after taking a neck cut during hip replacement after previous dynamic hip screw fixation. At 2-year follow-up, there was a statistically significant improvement in the Harris hip score: from a mean preoperative score of 35 ± 7.975 to a mean postoperative score of 89.38 ± 4.870 (P < 0.001). Stem sinking and Type AL (Vancouver classification for periprosthetic fracture) periprosthetic fracture in 1 patient with a tapered stem was noted. Good acetabular inclination was achieved in all cases. At 2-year follow-up, all patients were able to carry out their daily activities. This is a novel technique with the advantage of avoiding iatrogenic femoral neck fracture in an osteoporotic bone.

Outcomes of dual mobility components in total hip arthroplasty: a systematic review of the literature.

AIMS: Instability remains a challenging problem in both primary and revision total hip arthroplasty (THA). Dual mobility components confer increased stability, but there are concerns about the unique complications associated with these designs, as well as the long-term survivorship. MATERIALS AND METHODS: We performed a systematic review of all English language articles dealing with dual mobility THAs published between 2007 and 2016 in the MEDLINE and Embase electronic databases. A total of 54 articles met inclusion criteria for the final analysis of primary and revision dual mobility THAs and dual mobility THAs used in the treatment of fractures of the femoral neck. We analysed the survivorship and rates of aseptic loosening and of intraprosthetic and extra-articular dislocation. RESULTS: For the 10 783 primary dual mobility THAs, the incidence of aseptic loosening was 1.3% (142 hips); the rate of intraprosthetic dislocation was 1.1% (122 hips) and the incidence of extra-articular dislocation was 0.46% (41 hips). The overall survivorship of the acetabular component and the dual mobility components was 98.0%, with all-cause revision as the endpoint at a mean follow-up of 8.5 years (2 to 16.5). For the 3008 revision dual mobility THAs, the rate of aseptic acetabular loosening was 1.4% (29 hips); the rate of intraprosthetic dislocation was 0.3% (eight hips) and the rate of extra-articular dislocation was 2.2% (67 hips). The survivorship of the acatabular and dual mobility components was 96.6% at a mean of 5.4 years (2 to 8). For the 554 dual mobility THAs which were undertaken in patients with a fracture of the femoral neck, the rate of intraprosthetic dislocation was 0.18% (one hip), the rate of extra-articular dislocation was 2.3% (13 hips) and there was one aseptic loosening. The survivorship was 97.8% at a mean of 1.3 years (0.75 to 2). CONCLUSION: Dual mobility articulations are a viable alternative to traditional bearing surfaces, with low rates of instability and good overall survivorship in primary and revision THAs, and in those undertaken in patients with a fracture of the femoral neck. The incidence of intraprosthetic dislocation is low and limited mainly to earlier designs. High-quality, prospective, comparative studies are needed to evaluate further the use of dual mobility components in THA. Cite this article: Bone Joint J 2018;100-B:11-19.

Surgical prevention of femoral neck fractures in elderly osteoporotic patients: a randomised controlled study on the prevention nail system device.

INTRODUCTION:: Hip fractures represent an enormous challenge for our health care system. The aim of this randomised controlled trial was to assess both efficacy and safety of a novel device called Prevention Nail System (PNS) and developed for the surgical prevention of a contralateral femoral neck fracture (FNF) in elderly osteoporotic patients. METHODS:: Primary outcome was to evaluate, in patients suffering from osteoporotic FNF, the effectiveness of PNS in reducing the incidence of a contralateral hip fracture. Secondary outcome was to evaluate the safety of this device therefore intra- and postoperative complications were recorded. RESULTS:: 72 patients, with an age ⩾65 years old, were enrolled (38 study group (group A) and 34 control group (group B). 3 and 5 contralateral FNF were recorded respectively in group A and B. An interim analysis showed a non-effectiveness of the device therefore enrollment was suspended. DISCUSSION:: In all group A failures a difficult positioning of the PNS was recorded: surgical techniques errors may have affected the result. Nevertheless, it is improbable to hypothesise that, without substantial modifications to the PNS design, this could significantly reduce the incidence of FNF. Considering that current pharmacological approach can achieve, at best, a marginal reduction in FNF especially in patients at high risk, complementary approaches to provide immediate prevention of hip fractures may need to be developed. CLINICAL TRIAL PROTOCOL:: N° 263. 03 June 2008.

The Effect of Abaloparatide-SC on Fracture Risk Is Independent of Baseline FRAX Fracture Probability: A Post Hoc Analysis of the ACTIVE Study.

Daily subcutaneous (SC) injections of the investigational drug abaloparatide-SC (80 mcg) for 18 months significantly decrease the risk of vertebral and nonvertebral fracture compared with placebo in postmenopausal women. We examined the efficacy of abaloparatide-SC as a function of baseline fracture risk, assessed using the FRAX tool. Baseline clinical risk factors (age, body mass index [BMI], prior fracture, glucocorticoid use, rheumatoid arthritis, and smoking) were entered into country-specific FRAX models to calculate the 10-year probability of major osteoporotic fractures, with or without femoral neck bone mineral density (BMD). The interaction between probability of a major osteoporotic fracture and treatment efficacy was examined by a Poisson regression. A total of 821 women randomized to placebo and 824 women to abaloparatide-SC, mean age 69 years in both groups, were followed for up to 2 years. At baseline, the 10-year probability of major osteoporotic fractures (with BMD) ranged from 2.3% to 57.5% (mean 13.2%). Treatment with abaloparatide-SC was associated with a 69% (95% confidence interval [CI] 38-85%) decrease in major osteoporotic fracture (MOF) and a 43% (95% CI 9-64%) decrease in any clinical fracture compared with placebo. For all outcomes, hazard ratios tended to decrease (ie, greater efficacy) with increasing fracture probability. Whereas the interaction approached significance for the outcome of any fracture (p = 0.11), there was no statistically significant interaction for any of the fracture outcomes. Similar results were noted when FRAX probability was computed without BMD. Efficacy of abaloparatide-SC to decrease the risk of major osteoporotic fracture or any clinical fracture in postmenopausal women with low BMD and/or prior fracture appears independent of baseline fracture probability. © 2017 American Society for Bone and Mineral Research.

Physical Activity for Strengthening Fracture Prone Regions of the Proximal Femur.

PURPOSE OF REVIEW: Physical activity improves proximal femoral bone health; however, it remains unclear whether changes translate into a reduction in fracture risk. To enhance any fracture-protective effects of physical activity, fracture prone regions within the proximal femur need to be targeted. RECENT FINDINGS: The proximal femur is designed to withstand forces in the weight-bearing direction, but less so forces associated with falls in a sideways direction. Sideways falls heighten femoral neck fracture risk by loading the relatively weak superolateral region of femoral neck. Recent studies exploring regional adaptation of the femoral neck to physical activity have identified heterogeneous adaptation, with adaptation principally occurring within inferomedial weight-bearing regions and little to no adaptation occurring in the superolateral femoral neck. There is a need to develop novel physical activities that better target and strengthen the superolateral femoral neck within the proximal femur. Design of these activities may be guided by subject-specific musculoskeletal modeling and finite-element modeling approaches.

Effect of monthly intravenous ibandronate injections on vertebral or non-vertebral fracture risk in Japanese patients with high-risk osteoporosis in the MOVER study.

We examined the efficacy of intravenous (IV) ibandronate 1 mg/month in patient subgroups in the phase III MOVER study. Here we present results of analyses on the incidence of fractures in patients with prevalent vertebral fractures (1 or ≥2, and ≥3) at screening and femoral neck (FN) bone mineral density (BMD) T scores ≥-2.5 or <-2.5, and <-3.0 at baseline. The per-protocol set comprised 1134 patients (ibandronate 0.5 mg/month n = 376; ibandronate 1 mg/month n = 382; risedronate oral 2.5 mg/day n = 376). The incidence of vertebral fractures in patients with 1 or ≥2 prevalent vertebral fractures was 11.2 and 20.4 %, respectively, with ibandronate 1 mg/month, and 12.6 and 22.1 %, respectively, with risedronate. In patients with FN BMD T scores ≥-2.5 or <-2.5, the vertebral fracture incidence was 13.7 and 16.4 %, respectively, with ibandronate 1 mg/month, and 17.3 and 19.1 %, respectively, with risedronate. The incidence of non-vertebral fractures in patients with ≥2 prevalent vertebral fractures or FN BMD T score <-2.5 was 7.6 and 7.6 %, respectively, with ibandronate 1 mg/month, and 9.5 and 9.4 %, respectively, with risedronate. Fracture incidence was consistently lower, but not significant, with ibandronate 1 mg/month than with risedronate in patients with ≥2 prevalent vertebral fractures and FN BMD T score <-2.5. The efficacy of the fracture reduction of monthly IV ibandronate appears consistent and seemingly independent of the number of prevalent vertebral fractures or baseline BMD values.

Head-Neck Osteoplasty has Minor Effect on the Strength of an Ovine Cam-FAI Model: In Vitro and Finite Element Analyses.

BACKGROUND: Osteochondroplasty of the head-neck region is performed on patients with cam femoroacetabular impingement (FAI) without fully understanding its repercussion on the integrity of the femur. Cam-type FAI can be surgically and reproducibly induced in the ovine femur, which makes it suitable for studying corrective surgery in a consistent way. Finite element models built on quantitative CT (QCT) are computer tools that can be used to predict femoral strength and evaluate the mechanical effect of surgical correction. QUESTIONS/PURPOSES: We asked: (1) What is the effect of a resection of the superolateral aspect of the ovine femoral head-neck junction on failure load? (2) How does the failure load after osteochondroplasty compare with reported forces from activities of daily living in sheep? (3) How do failure loads and failure locations from the computer simulations compare with the experiments? METHODS: Osteochondroplasties (3, 6, 9 mm) were performed on one side of 18 ovine femoral pairs with the contralateral intact side as a control. The 36 femurs were scanned via QCT from which specimen-specific computer models were built. Destructive compression tests then were conducted experimentally using a servohydraulic testing system and numerically via the computer models. Safety factors were calculated as the ratio of the maximal force measured in vivo by telemeterized hip implants during the sheep's walking and running activities to the failure load. The simulated failure loads and failure locations from the computer models were compared with the experimental results. RESULTS: Failure loads were reduced by 5% (95% CI, 2%-8%) for the 3-mm group (p = 0.0089), 10% (95% CI, 6%-14%) for the 6-mm group (p = 0.0015), and 19% (95% CI, 13%-26%) for the 9-mm group (p = 0.0097) compared with the controls. Yet, the weakest specimen still supported more than 2.4 times the peak load during running. Strong correspondence was found between the simulated and experimental failure loads (R2 = 0.83; p < 0.001) and failure locations. CONCLUSIONS: The resistance of ovine femurs to fracture decreased with deeper resections. However, under in vitro testing conditions, the effect on femoral strength remains small even after 9 mm correction, suggesting that femoral head-neck osteochondroplasty could be done safely on the ovine femur. QCT-based finite element models were able to predict weakening of the femur resulting from the osteochondroplasty. CLINICAL RELEVANCE: The ovine femur provides a seemingly safe platform for scientific evaluation of FAI. It also appears that computer models based on preoperative CT scans may have the potential to provide patient-specific guidelines for preventing overcorrection of cam FAI.

Biomechanical optimization of subject-specific implant positioning for femoral head resurfacing to reduce fracture risk.

Peri-prosthetic femoral neck fracture after femoral head resurfacing can be either patient-related or surgical technique-related. The study aimed to develop a patient-specific finite element modelling technique that can reliably predict an optimal implant position and give minimal strain in the peri-prosthetic bone tissue, thereby reducing the risk of peri-prosthetic femoral neck fracture. The subject-specific finite element modelling was integrated with optimization techniques including design of experiments to best possibly position the implant for achieving minimal strain for femoral head resurfacing. Sample space was defined by varying the floating point to find the extremes at which the cylindrical reaming operation actually cuts into the femoral neck causing a notch during hip resurfacing surgery. The study showed that the location of the maximum strain, for all non-notching positions, was on the superior femoral neck, in the peri-prosthetic bone tissue. It demonstrated that varus positioning resulted in a higher strain, while valgus positioning reduced the strain, and further that neutral version had a lower strain.

A new approach to prevent contralateral hip fracture: Evaluation of the effectiveness of a fracture preventing implant.

BACKGROUND: Among the millions of people suffering from a hip fracture each year, 20% may sustain a contralateral hip fracture within 5 years with an associated mortality risk increase reaching 64% in the 5 following years. In this context, we performed a biomechanical study to assess the performance of a hip fracture preventing implant. METHODS: The implant consists of two interlocking peek rods unified with surgical cement. Numerical and biomechanical tests were performed to simulate single stance load or lateral fall. Seven pairs of femurs were selected from elderly subjects suffering from osteoporosis or osteopenia, and tested ex-vivo after implantation of the device on one side. FINDINGS: The best position for the implant was identified by numerical simulations. The loadings until failure showed that the insertion of the implant increased significantly (P<0.05) both fracture load (+18%) and energy to fracture (+32%) of the implanted femurs in comparison with the intraindividual controls. The instrumented femur resisted the implementation of the non-instrumented femur fracture load for 30 cycles and kept its performance at the end of the cyclic loading. INTERPRETATION: Implantation of the fracture preventing device improved both fracture load and energy to fracture when compared with intraindividual controls. This is consistent with previous biomechanical side-impact testing on pairs of femur using the same methodology. Implant insertion seems to be relevant to support multiple falls and thus, to prevent a second hip fracture in elderly patients.

Gaps and opportunities in the management of the young femoral neck fracture.

Femoral neck fractures in young adults are difficult to treat. There are substantial gaps in our knowledge regarding treatment and prevention of young adult femoral neck fractures. Avoiding malunion or nonunion of these fractures after fixation remains a challenge. Currently available fixation techniques may allow for healing to occur, but in a shortened position, with negative consequences on gait mechanics and physical function. Osteonecrosis remains a problem, affecting up to half of patients who sustain femoral neck fractures. Achieving reliable healing may require a reconsideration of fracture fixation implants as well as biological methods to address metabolic, endocrine, and/or genetic abnormalities that may be present in the young adult femoral neck fracture patient. Also, prevention of low-energy femoral neck fractures (e.g. stress fracture) remains an area ripe for investigation.

Fracture prevention by prophylactic femoroplasty of the proximal femur--metallic compared with cemented augmentation.

OBJECTIVES: To compare 2 different femoral neck augmentation techniques at improving the mechanical strength of the femoral neck. METHODS: Twenty pairs of human cadaveric femora were randomly divided into 2 groups. In 1 group, the femora were augmented with a steel spiral; the other group with the cemented technique. The untreated contralateral side served as an intraindividual control. Fracture strength was evaluated using an established biomechanical testing scenario mimicking a fall on the greater trochanter (Hayes fall). RESULTS: The peak load to failure was significantly higher in the steel spiral group (P = 0.0024) and in the cemented group (P = 0.001) compared with the intraindividual controls. The peak load to failure showed a median of 3167 N (1825-5230 N) in the spiral group and 2485 N (1066-4395 N) in the spiral control group. The peak load to failure in the cemented group was 3698 N (SD ± 1249 N) compared with 2763 N (SD ± 1335 N) in the cement control group. Furthermore, fracture displacement was clearly reduced in the steel spiral group. CONCLUSIONS: Femoral augmentations using steel spirals or cement-based femoroplasty are technically feasible procedures. Our results demonstrate that a prophylactic reinforced proximal femur has higher strength when compared with the untreated contralateral limb. Prophylactic augmentation has potential to become an auxiliary treatment option to protect the osteoporotic proximal femur against fracture.

Adherence to oral bisphosphonates and the risk of subtrochanteric and femoral shaft fractures among female medicare beneficiaries.

UNLABELLED: Previous studies have shown an association between duration of bisphosphonate use and atypical femur fractures. This cohort study showed an increasingly higher risk of subtrochanteric and femoral shaft fractures among those who were more adherent to oral bisphosphonates. INTRODUCTION: Long-term use of oral bisphosphonates has been implicated in an increased risk of atypical femur fractures located in subtrochanteric and femoral shaft regions. Another measure of drug exposure, medication adherence, however, has not been investigated. METHODS: Among all Medicare fee-for-service female beneficiaries from 2006-2010, we followed 522,287 new bisphosphonate users from their index prescription until being censored or having a primary diagnosis of closed subtrochanteric/femoral shaft or intertrochanteric/femoral neck fractures. Data about radiographs of fracture site and features were not available. Adherence was classified according to the medication possession ratio (MPR) as the following: MPR < 1/3 as less compliant, MPR ≥ 1/3- < 2/3 as compliant, and MPR ≥ 2/3 as highly compliant. Alternative cutoff points at 50 and 80% were also used. Survival analysis was used to determine the cumulative incidence and hazard of subtrochanteric/femoral shaft or intertrochanteric/femoral neck fractures. RESULTS: There was a graded increase in incidence of subtrochanteric/femoral shaft fractures as the level of adherence increased (Gray's test, P < 0.001). The adjusted hazard ratio (HR) for the highly compliant vs. the less compliant was 1.23 (95% Confidence Interval [CI] 1.06-1.43) overall, became significant after 2 years of follow-up (HR = 1.51, 95% CI 1.06-2.15) and reached the highest risk in the fifth year (HR = 4.06, 95% CI 1.47-11.19). However, age-adjusted incidence rates of intertrochanteric/femoral neck fractures were significantly lower among highly compliant beneficiaries, compared to less compliant users (HR = 0.69, 95% CI 0.66-0.73). Similar results were obtained when the cutoff points for being compliant and highly compliant were set at 50 and 80 %, respectively. CONCLUSIONS: Subtrochanteric/femoral shaft fractures, unlike intertrochanteric/femoral neck fractures, are positively associated with higher adherence to long-term (≥3 years) oral bisphosphonates in the elderly female Medicare population.

Biomechanical analysis of impending femoral neck fractures: the role of percutaneous cement augmentation for osteolytic lesions.

BACKGROUND: Management of impending pathologic femoral neck fractures includes internal fixation, arthroplasty and megaprostheses. The study aim was to determine the augmentative effect of cement injection for minimally invasive treatment of femoral neck lesions. METHODS: Twenty-seven cadaveric femora received a simulated osteolytic lesion previously shown to decrease the femur's failure load by 50%. Specimens were allocated to three groups of nine and loaded to failure in simulated single-leg stance: (1) percutaneous cementation + internal fixation (PCIF); (2) percutaneous cementation (PC); and (3) internal fixation (IF). Lesion-only and augmented finite element models were virtually loaded and stresses were queried adjacent to the lesion. FINDINGS: PCIF resulted in the largest failure load though the increase was not significantly greater than the PC or IF groups. Inspection of the PC and PCIF specimens indicated that the generation of a cement column that spanned the superior and inferior cortices of the femoral neck increased failure loads significantly. Finite element analysis indicated that IF and PCIF constructs decreased the stress adjacent to the lesion to intact femur levels. Cementation without superior-to-inferior femoral neck cortical contact did not restore proximal femoral stress toward the intact condition. INTERPRETATION: Internal fixation alone and internal fixation with or without cementation produce similar levels of mechanical augmentation in femora containing a high-risk lesion of impending fracture. A cement injection technique that produces a cement column contacting the superior and inferior femoral neck cortices confers the highest degree of biomechanical stability, should percutaneous cementation alone be performed.

Secondary prevention of osteoporosis in non-neck of femur fragility fractures: is it value for money? A retrospective, prospective and cross-sectional cohort study.

BACKGROUND: Osteoporosis is one of the commonest bone diseases in which bone fragility is increased. Over 300,000 patients present to hospitals in the UK with fragility fractures each year, with medical and social care costs - most of which relate to hip fracture care - at around £2 billion. The number of these fractures rises by 2% a year. The 30 days mortality is 10% and 30% at 1 year. The purpose of this study is to review the current practice according to NICE and BOA guidelines of secondary prevention of osteoporosis and to suggest changes to these guidelines. METHODS: Patients over 50 years old admitted as inpatients to our facility with non-neck-of-femur (NOF) fragility fractures in March and September 2008 were studied. Retrospectively (March), looking for risk factors and if treated or not, then prospectively (September), after introducing the new trauma admission sheet. Also cross-sectional study was performed by comparing the services provided for NOF and non-NOF fragility fractures in September. Two-sample t test is used to compare between percentages. RESULTS: Twenty-nine percent of fragility fractures are non-NOF fractures with a mean age of 70 years, while the remaining 71% are NOF fractures with a mean age of 80 years. There is a great difference in the care provided to these patients: non-NOF fragility fractures got less attention for assessment of osteoporosis (25%) and obtained less interest in investigations by medical staff (11%) and, finally, less intentions to treat osteoporosis (35%), compared to NOF fractures in which 35% of cases were assessed, 47% were investigated and 71% were treated for osteoporosis. Twenty-five percent of NOF fracture patients were found to have previous fragility fractures in the preceding years, while only 6% were on osteoporosis treatment before the fracture. CONCLUSION: Osteoporosis (a new epidemic) is the most common disease of the bone and its incidence is rising rapidly as the population ages. Though treatable, it is often left untreated. We believe that treating patients with non-NOF fragility fractures from osteoporosis before proceeding to NOF fractures would improve their quality of life and reduce the burden on hospital services and funding.

The incidence of vitamin D deficiency amongst patients with a femoral neck fracture: are current bone protection guidelines sufficient ?

Vitamin D is required for calcium homeostasis and bone metabolism. This prospective observational study examined the incidence of vitamin D deficiency amongst patients with a fracture of the femoral neck, and the correlation between pre-admission use of bone-protection medication and vitamin D levels. Vitamin D assays were available in 75 out of 151 patients admitted with a hip fracture in February-March 2012; the assays were performed within one week of admission and surgery. The incidence of suboptimal vitamin D levels was 90% (68/75), with severe deficiency (<15nmol/l) or deficiency (<30nmol/l) seen in 71% (53/75). Only 7 patients were on bone protection medication at the time of admission, and all of them had suboptimal vitamin D levels. This suggests that the prevention is practically inexistent or at best insufficient. According to the literature, vitamin D deficiency is also associated with falls and maybe with outcome of surgery. Current management strategies may not be sufficient to address vitamin D deficiency and are overlooking an important and potentially modifiable risk factor.