Atypical Subtrochanteric Fractures Research Articles

Surgical management and outcomes following atypical subtrochanteric femoral fractures − results from a matched-pair analysis of the registry for geriatric trauma of the German Trauma Society

Background and objectivesThe outcomes of patients with atypical subtrochanteric fractures (ASFs) remain unclear. Data from a large international geriatric trauma registry were analysed to examine the outcome of patients with ASFs compared to patients with typical osteoporotic subtrochanteric fractures (TSFs).Materials and methodsData from the Registry for Geriatric Trauma of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie [DGU]) (ATR-DGU) were analysed. All patients treated surgically for ASFs or TSFs were included in this analysis. Across both fracture types, a paired matching approach was conducted, where statistical twins were formed based on background characteristics sex, age, American Society of Anesthesiologists (ASA) score and walking ability. In-house mortality and mortality rates at the 120-day follow-up, as well as mobility at 7 and 120 days, the reoperation rate, hospital discharge management, the hospital readmission rate at the 120-day follow-up, health-related quality of life, type of surgical treatment and anti-osteoporotic therapy at 7 and 120 days, were assessed as outcome measures using a multivariate logistic regression analysis.ResultsAmongst the 1,800 included patients, 1,781 had TSFs and 19 had ASFs. Logistic regression analysis revealed that patients with ASFs were more often treated with closed intramedullary nailing (RR = 3.59, p < 0.001) and had a higher probability of vitamin D supplementation as osteoporosis therapy at 120 days (RR = 0.88, p < 0.002). Patients with ASFs were also more likely to live at home after surgery (RR = 1.43, p < 0.001), and they also tended to continue living at home more often than patients with TSFs (RR = 1.33, p < 0.001). Accordingly, patients with TSFs had a higher relative risk of losing their self-sufficient living status, as indicated by increased rates of patients living at home preoperatively and being discharged to nursing homes (RR = 0.19, p < 0.001) or other hospitals (RR = 0.00, p < 0.001) postoperatively.ConclusionsSurgical treatment of ASFs was marked by more frequent use of closed intramedullary fracture reduction. Furthermore, patients with ASFs were more likely to be discharged home and died significantly less often in the given timeframe. The rate of perioperative complications, as indicated by nonsignificant reoperation rates, as well as patient walking abilities during the follow-up period, remained unaffected.

Bisphosphonates and atypical femoral fractures: Is the location of the fracture associated with the time of consolidation?

IntroductionBisphosphonates are commonly prescribed to mitigate the effects of osteoporosis, a condition associated with an increased risk of fracture.However, despite their success, there has been growing concern regarding the long-term use of bisphosphonates because of the increased risk of atypical subtrochanteric fractures of the femur (AFFs).The objective of this study was to describe a cohort of patients with AFFs and evaluate the risk of evolving to non-union, the time of consolidation associated with the location of the fracture, the time of use of the drug, and the implant involved in its treatment. MethodsThis retrospective study recruited patients between June 2008 and May 2018. We identified patients with AFFs according to the task force criteria and a history of bisphosphonate use.We included all patients older than 65 years, with long-term use of bisphosphonates, AFF criteria according to the task force, and a follow-up of 12 months or longer.We studied the following variables: the time of use of bisphosphonates, localization of the fracture according to Hyodo et al., implant use, and fracture healing time, considering the presence of bone callus observed in two radiologic projections, which were measured in weeks. ResultsBetween June 2008 and May 2018, 72 patients met the task force criteria for AFFs.A total of 67 patients were included in this study. From this total, 37 were in the proximal region of the femur and 31 corresponded to the diaphyseal region.Univariate and multivariate analyses showed statistical significance in the time of bone healing compared with the different locations of the fracture along the femur. ConclusionAccording to our study, the localization of AFFs in patients with a history of bisphosphonate use influences the duration of bone healing.

The Korean hip fracture registry study

BackgroundThe purpose of the Korean Hip Fracture Registry (KHFR) Study is to establish a nationwide, hospital-based prospective cohort study of adults with hip fracture to explore the incidence and risk factors of second osteoporotic fractures for a Fracture Liaison Service (FLS) model.MethodsThe KHFR, a prospective multicenter longitudinal study, was launched in 2014. Sixteen centers recruited participants who were treated for hip fracture. The inclusion criteria were patients, who were treated for proximal femur fracture due to low-energy trauma and aged 50 or more at the time of injury. Until 2018, 5,841 patients were enrolled in this study. Follow-up surveys were conducted annually to determine occurrence of second osteoporotic fracture, and 4,803 participants completed at least one follow-up survey.DiscussionKHFR is a unique resource of individual level on osteoporotic hip fracture with radiological, medical, and laboratory information including DXA (dual energy x-ray absorptiometry), bone turnover marker, body composition, and hand grip strength for future analyses for FLS model. Modifiable factors for mortality after hip surgery is planned to be identified with nutritional assessment and multi-disciplinary interventions from hospitalization to follow-ups. The proportions of femoral neck, intertrochanteric, and subtrochanteric fractures were 517 (42.0%), 730 (53.6%), and 60 (4.4%), respectively, from 2014 to 2016, which was similar in other studies. Radiologic definition of atypical subtrochanteric fracture was adopted and 17 (1.2%) fractures among 1,361 proximal femoral fractures were identified. Internal fixation showed higher reoperation rate compared to arthroplasty in unstable intertrochanteric fractures (6.1% vs. 2.4%, p = 0.046) with no significant difference in mortality. The KHFR plans to identify outcomes and risk factors associated with second fracture by conducting a 10-year cohort study, with a follow-up every year, using 5,841 baseline participants.Trial registrationPresent study was registered on Internet-based Clinical Research and Trial management system (iCReaT) as multicenter prospective observational cohort study (Project number: C160022, Date of registration: 22th, Apr, 2016).

Functional and Radiological Outcome in Atypical Subtrochanteric Femur Fracture After Surgical Fixation: A Retrospective Observational Study.

Background: Treatment for osteoporosis can have catastrophic side effects, including the uncommon fracture known as an atypical femur fracture (AFF), which is related to the long-term usage of antiresorptive agents. Bisphosphonate therapy may lead to significant and chronic suppression of bone turnover, impairing the bone's remodelling property and finally leading to incomplete or complete atypical femur fracture. AFF was defined by the American Society for Bone and Mineral Research (ASBMR) Task Force in 2010 and is far less prevalent than proximal femur (hip) fracture, with an incidence of 2 to 78 per 100,000 patients per year following two to eight years of bisphosphonate therapy, respectively. Due to the rarity of the fracture, it is still not clear what the functional and radiological outcome will be after surgery.Aim: To identify the functional and radiological outcomes of surgical fixation of atypical femur fractures.Methods: The study was conducted in a tertiary healthcare centre after scientific and ethical clearance from the competent authority. Between January 2018 and December 2021, individuals who were diagnosed with an atypical subtrochanteric femoral fracture associated with the use of bisphosphonates and treated surgically were retrospectively evaluated. The study's inclusion and exclusion criteria were used to include 20 patients. The features of an atypical subtrochanteric fracture were congruent with the radiographic findings. Most of the patients were treated with internal fixation with intramedullary osteosynthesis in standard with or without plate osteosynthesis. They were then followed up for a year to look at the functional and radiological outcomes.Results: All of the 20 patients who were included had an atypical subtrochanteric fracture, with 15 of them being female and 5 of them being male. The patients' mean age at surgery was 65.12 (range 49 to 82) years, and their average history of bisphosphonate use was 3 (range 2.5 to 5) years. All patients were treated surgically. We found that five months was the mean period for bone union (p = 0.990). Within six months, bone union was achieved in 11 patients (55 %) (p = 0.884). Five patients (about 25%) had implant failure and non-union, requiring two to three revision surgeries. At three, six, and nine months, the mean visual analogue score (VAS) was 4.14, 3.12, and 1.85, respectively. The modified Hip Harris Score had a mean of 72.66 and 15 patients (about 75% of them) could walk normally again after a fracture. The mean of the modified HHS was 72.66, and the VAS at three, six, and nine months was 4.14, 3.12, and 1.85, respectively.Conclusion: AFFs are rare fractures that must be treated effectively, and most of them require surgery. Successful treatment of AFF is possible by the use of intramedullary fixation, which enhances axial stability, serves as an internal splint, and lessens the likelihood of implant failure. A good functional and radiological prognosis can come from a stable fixation and a fracture that has been reduced anatomically.

Risk of subtrochanteric and femoral shaft fractures due to bisphosphonate therapy in asthma: a population-based nested case-control study.

Bisphosphonates are used as first-line treatment for osteoporosis; however, concerns have been raised over their association with atypical subtrochanteric (ST) and femoral shaft (FS) fractures. The potential risk of atypical ST/FS fractures from bisphosphonate use in asthma has not been examined. A nested case-control study was conducted using linked data from the Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) databases. Using an asthma cohort, we identified patients with atypical ST/FS fractures and sex, age, and practice-matched controls. Conditional logistic regression was used to determine the association between bisphosphonate exposure and atypical ST/FS fractures. From a cohort of 69,074 people with asthma, 67 patients with atypical ST/FS fractures and 260 matched control subjects were identified. Of the case patients, 40.3% had received bisphosphonates as compared with 14.2% of the controls corresponding to an adjusted odds ratio (aOR) of 4.42 (95%CI, 2.98 to 8.53). The duration of use influenced the risk with long-term users to be at a greater risk (> 5years vs no exposure; aOR = 7.67; 95%CI, 1.75 to 33.91). Drug withdrawal was associated with diminished odds of atypical ST/FS fractures. Regular review of bisphosphonates should occur in patients with asthma. The risks and benefits of bisphosphonate therapy should be carefully considered in consultation with the patient. To improve AFF prevention, early signs which may warrant imaging, such as prodromal thigh pain, should be discussed.

Paget ‘s Disease: Not So Typical for Atypical Femur Fracture

Introduction: Atypical femur fractures (AFF) are reported in patients taking prolonged bisphosphonate therapy, but Paget’s disease (PD) has been rarely reported as a cause of AFF. Case: 71-year-old female with past medical history of right hip osteoarthritis, seizure disorder, hypertension, and Hashimoto’s thyroiditis presented with persistent right hip pain. There was no history of trauma or fall. She had otosclerosis with bilateral hearing loss and bilateral stapedectomies. Her medications were primidone, levothyroxine, lisinopril-hydrochlorothiazide, and vitamin D. She did not smoke tobacco or drink alcohol. She had elevated serum alkaline phosphatase of 300 U/L (35–104). The X-ray of the skull was negative for any cortical thickening. CT of right femur revealed cortical thickening and coarsening of trabeculae of the proximal right femur consistent with PD and incomplete atypical subtrochanteric proximal fracture. Urine NTx 303 BCE/mM Cr (<89). Bone scan showed uptake in the R proximal femur, L distal tibia, and L3-L4 vertebral bodies suspicious of PD. DXA showed osteopenia. She was given zoledronic acid 5 mg IV. Discussion: PD leads to an increased incidence of fractures particularly of the lower extremities with most fractures transverse in nature. Non-union is not uncommon1. Stress fractures in PD are caused by disorganized bone remodeling due to excessive breakdown and formation of bone. Our patient met the major criteria for AFF as per the ASBMR 2010 task force report but there was no exposure to bisphosphonates2. The ASBMR task force recommended that bisphosphonates should be discontinued in patients with bisphosphonate-associated AFF due to their severely suppressed bone turnover status. On the other hand, the AFF in patients with PD may heal in response to bisphosphonate treatment.

Surgical outcome of atypical subtrochanteric fracture treated by intramedullary nailing with plate augmentation in the lateral decubitus position

Surgical outcome of atypical subtrochanteric fracture treated by intramedullary nailing with plate augmentation in the lateral decubitus position

Bisphosphonate-related Femoral Shaft Fracture

The efficacy of using bisphosphonate therapy to treat osteoporotic patients is becoming more widely known, but the potential side effects may not be. While this class of drugs is generally safe, concerns have emerged regarding risks of atypical subtrochanteric fractures associated with long-term use. There have been a number of case reports discussing the association of patients on bisphosphonates who suffer a non-traumatic or a low-energy mechanism of injury atypical of subtrochanteric fractures. The purpose of this case report is to raise awareness of this potential side effect and provide increased clinical suspicion for this rare type of fracture.

Critical differences between subtrochanteric and diaphyseal atypical femoral fractures: analyses of 51 cases at a single institution in Korean population

Although AFF could be divided into subtrochanteric and diaphyseal fracture according to the location of fractures, there is a lack of evidence regarding differences between two fractures and etiology of the occurrence. The aim of study is to determine differences between atypical subtrochanteric and diaphyseal fracture in Korean population. Between February 2010 and March 2015, 51 AFFs in 40 patients were included in this study. Their medical records were retrospectively reviewed. The AFF patients satisfied all the diagnostic criteria of the 2014 revised edition of the ASMBR. To analyze the differences according to the location of fracture, the AFFs were divided into subtrochanteric (n = 16) and diaphyseal (n = 35) fracture groups. The following factors were compared between two groups: patients' demographics, underlying diseases, laboratory findings (serum-25(OH) VitD3, osteocalcin, c-telopeptide, ALP, Ca, and P), bone mineral density (BMD), duration of bisphosphonate (BP) usage, and lateral bowing of the femur at time of the fracture. All AFFs happened in female patients (mean age, 73.8years) who have received bisphosphonate treatments except three patients. The mean duration of bisphosphonate usage was 95.3months. Between the two groups, demographic data (age, height, weight, and BMI), underlying diseases, laboratory findings, hip BMD, and duration of BP treatment were comparable to each other (p > 0.05). However, the subtrochanteric fracture group showed higher FNSBA (femoral neck shaft bowing angle, p < 0.001) and spine BMD (p = 0.014) compared to the diaphyseal fracture group. Angle of lateral bowing (FNSBA) and spine BMD showed significant differences between subtrochanteric and diaphyseal atypical fracture groups. According to our results, femoral bowing and spine BMD may play important roles in the AFF locations.

Surgical outcome of atypical subtrochanteric and femoral fracture related to bisphosphonates use in osteoporotic patients with or without teriparatide treatment

BackgroundAtypical subtrochanteric fracture and femoral fracture have been considered to be rare complications related to long-term bisphosphonates use. A reduced bone turnover rate may lead to delayed bone healing. Limited data have revealed that teriparatide treatment may reverse the effect of bisphosphonates and be effective in bone healing.MethodsWe reviewed patients with atypical subtrochanteric and femoral fracture related to bisphosphonates use between January 2008 and December 2014. Thirteen female patients were enrolled. Radiographic findings were compatible with the characteristics of atypical fracture. Surgical intervention was performed for all, and teriparatide use was advised postoperatively. Outcome measures included perioperative results, and clinical and radiographic outcome.ResultsOf the 13 female patients enrolled, 10 had subtrochanteric and 6 had proximal femoral fracture; 3 had bilateral fractures. The mean age of the patients at surgery was 70.15±6.36 years. Most fractures (68.8%) presented prodromal thigh pain. All patients were treated with an intramedullary fixation system without severe complications. The patients were divided into 2 groups based on whether they had received treatment with teriparatide or not. The mean time to bone union was 4.4 months in the teriparatide-treated group, and 6.2 months in the non-teriparatide-treated group (p=0.116). Six patients (75%) in the teriparatide-treated group and 4 (50%) in the non-teriparatide-treated group (p= 0.3) achieved bone union within 6 months. The means of the modified Harris Hip Score and Numerical Rating Scale were significantly better in the teriparatide-treated group at postoperative 6 months. Seven patients had the same ability to walk at the 1-year follow-up as they did before the atypical fracture.ConclusionsTeriparatide treatment in patients with atypical fracture may help in fracture healing, hip function recovery, and pain relief in this reduced bone turnover patient group.

Retrospective review of patients with atypical bisphosphonate related proximal femoral fractures

IntroductionPatients may be at an increased risk of atypical proximal femoral fractures with prolonged bisphosphonate use. Patients and methodsThis was a retrospective review of patients who sustained a subtrochanteric fracture of the femur in our department between April 2009 and March 2014. The radiographs were reviewed for features of atypical femoral fractures as described by the American Society of Bone Mineral Research. Results185 patients were coded according to the National Hip Fracture Database as having sustained a subtrochanteric fracture of the femur. Of these, 26 patients had radiographic findings consistent with an atypical subtrochanteric fracture. 5 patients were excluded as their histology confirmed malignancy. 12 patients were taking bisphosphonates on admission. All 12 patients were females taking alendronic acid on admission, who sustained the fracture as the result of minimal or no trauma and underwent long gamma nail fixation. The mean age was 71.6 years (range 62–79 years). The mean length of time on bisphosphonates prior to admission was 8.33 years (range 3–25 years). 9/12 patients had pre-existing symptoms for between 5days and 2 years prior to admission. 1 patient sustained a broken gamma nail 14 weeks post-operatively requiring revision. The mean time to discharge from theatre was 16days (range 5–57days). The mean time to radiological union in the patients in whom there was evidence was 24 weeks. ConclusionsIn this small group of patients, management of this fracture pattern can be complex with the potential for delayed or non-union and prodromal symptoms are common.

Healing of Atypical Subtrochanteric Femur Fractures After Cephalomedullary Nailing: Which Factors Predict Union?

The purpose of this study was to determine the healing rate and time to union of atypical subtrochanteric fractures treated with cephalomedullary nailing. Retrospective review, descriptive, and analytic study. Six level 1 trauma centers. The study included 42 patients with 48 displaced, atypical, bisphosphonate-associated subtrochanteric femur fractures who underwent surgical intervention. Cephalomedullary femur nailing. The main outcome measures were radiologic healing and time to union. The primary healing rate after cephalomedullary nailing of bisphosphonate-associated subtrochanteric femur fractures was 68.7% (33/48 patients). Mean time to union was 10.7 months. Malalignment was determined using the differences in neck-shaft angle (the difference between the normal side and the surgically repaired side) and sagittal angulation. These all proved to be significantly correlated with failure and delayed healing time. The cutoff points for neck-shaft angle, difference in neck-shaft angle, and sagittal angulation were 125.6, 4.4, and 5.5 degrees, respectively (receiver operating characteristic curve analysis). The healing rate of atypical subtrochanteric femur fractures treated with cephalomedullary nailing is lower than that previously reported for atypical femur fractures. The quality of fracture reduction proved to be the most important factor in bony union and time to union. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Bisphosphonates and atypical subtrochanteric fractures of the femur.

ObjectivesBisphosphonates are widely used as first-line treatment for primary and secondary prevention of fragility fractures. Whilst they have proved effective in this role, there is growing concern over their long-term use, with much evidence linking bisphosphonate-related suppression of bone remodelling to an increased risk of atypical subtrochanteric fractures of the femur (AFFs). The objective of this article is to review this evidence, while presenting the current available strategies for the management of AFFs.MethodsWe present an evaluation of current literature relating to the pathogenesis and treatment of AFFs in the context of bisphosphonate use.ResultsSix broad themes relating to the pathogenesis and management of bisphosphonate-related AFFs are presented. The key themes in fracture pathogenesis are: bone microdamage accumulation; altered bone mineralisation and altered collagen formation. The key themes in fracture management are: medical therapy and surgical therapy. In addition, primary prevention strategies for AFFs are discussed.ConclusionsThis article presents current knowledge about the relationship between bisphosphonates and the development of AFFs, and highlights key areas for future research. In particular, studies aimed at identifying at-risk subpopulations and organising surveillance for those on long-term therapy will be crucial in both increasing our understanding of the condition, and improving population outcomes.Cite this article: N. Kharwadkar, B. Mayne, J. E. Lawrence, V. Khanduja. Bisphosphonates and atypical subtrochanteric fractures of the femur. Bone Joint Res 2017;6:144–153. DOI: 10.1302/2046-3758.63.BJR-2016-0125.R1.

Bone turnover markers and the factors associated with atypical femur fractures among Japanese patients

Many previous reports have indicated that atypical femur fractures (AFFs) are associated with the administration of bisphosphonates (BPs). A number of risk factors and hypotheses regarding the pathogenesis of AFFs have been reported to date. The purpose of the present study was to identify the factors associated with AFFs in Japanese individuals and to elucidate the association between bone metabolism and AFFs by evaluating bone turnover markers (BTMs). We prospectively reviewed all patients with femur fractures and identified the patients with AFFs and typical femur fractures (TFFs). We collected the demographic and clinical data that were relevant to the present study, namely age, gender, affected side, affected site, concomitant medical history, and comorbid conditions, and measured the levels of BTMs within 24h after trauma. Welch’s test and Fisher’s exact probability test were used for the statistical analyses. A total of 338 patients, including 10 patients with AFFs and 328 patients with TFFs, were analyzed under the inclusion criteria. The use of BPs (p<0.001) and collagen disease and chronic granulomatous disease (CD/CGD) (p=0.025) were more frequently observed in patients with AFFs than in patients with TFFs, while the levels of BTMs, including N-terminal propeptides of type 1 procollagen (P1NP), isoform 5b of tartrate-resistant acid phosphatase (TRACP-5b) and undercarboxylated osteocalcin (ucOC) were significantly lower in patients with AFFs than in patients with TFFs. Furthermore, the level of TRACP-5b was found to be significantly lower in patients with atypical subtrochanteric fractures than in atypical diaphyseal fractures (p=0.025). Moreover, the levels of P1NP (p=0.016) and TRACP-5b (p=0.015) were found to be significantly lower in patients with AFFs than in patients with TFFs in a subgroup analysis of BPs users. The use of BPs was considered to be a factor associated with AFFs. Our comparison of the BTMs in patients with AFFs and TFFs indicated that the severe suppression of bone turnover was associated with the pathogenesis of AFFs. The extent of the influence of suppressed turnover on the pathogenesis of AFFs may differ depending on the fracture site.

Trends in the incidence of atypical femoral fractures and bisphosphonate therapy.

To report the trends in the incidence of typical and atypical femoral fractures (AFF) in patients aged >50 years from 2009 to 2014 and in the prescription of bisphosphonates for osteoporosis from 2001 to 2013 in Australia. 175 patients aged >50 years presenting to our hospital with an AO type 32 femoral shaft fracture between October 2009 and October 2014 were identified using a trauma database. Of them, 21 male and 110 female patients with a mean age of 75 years were reviewed. Radiographs were reviewed by 2 investigators blinded to the use of bisphosphonates. The femoral shaft fractures were classified as typical or atypical using the American Society of Bone and Mineral Research definition, and their annual incidence was compared. The trend and number of prescriptions for various bisphosphonates in Australia was determined using the Pharmaceutical Benefits Scheme statistics from 2001 to 2013. Of the 131 femoral shaft fractures, 65 were typical and 66 were atypical subtrochanteric (n=19) or diaphyseal (n=47) fractures that were complete (n=60) or incomplete (n=6). Four patients had sequential bilateral AFF. The 66 AFFs accounted for 5% of hip and shaft fractures. Women accounted for 80% of all femoral shaft fractures and 95% of AFF. The proportion of AFF was higher in women than men (63/110 vs. 3/21, relative risk=3.95, 95% CI=1.37- 11.39, p=0.0006). The mean length of hospital stay was 9.7 days shorter in the AFF patients (14.1 vs. 23.8 days, 95% CI=2.6-16.8 days, p=0.008). Patients with AFF were 8 years younger than those with proximal femoral fracture (73 vs. 81 years, p<0.0001). There was no trend in the annual incidence or proportion of AFF from 2009 to 2014 (p=0.70). The bisphosphonate usage was highest in 2007 with 260 000 yearly patient treatments and had declined by 30% by the end of 2013. AFF accounted for half of all femoral shaft fractures in patients aged >50 years. Women accounted for 80% of all femoral shaft fractures and 95% of AFF. The incidence of AFF was no longer increasing possibly related to decreased prescription of bisphosphonates in preceding years.

MicroRNAs in Osteoclastogenesis and Function: Potential Therapeutic Targets for Osteoporosis.

Abnormal osteoclast formation and resorption play a fundamental role in osteoporosis pathogenesis. Over the past two decades, much progress has been made to target osteoclasts. The existing therapeutic drugs include bisphosphonates, hormone replacement therapy, selective estrogen receptor modulators, calcitonin and receptor activator of nuclear factor NF-κB ligand (RANKL) inhibitor (denosumab), etc. Among them, bisphosphonates are most widely used due to their low price and high efficiency in reducing the risk of fracture. However, bisphosphonates still have their limitations, such as the gastrointestinal side-effects, osteonecrosis of the jaw, and atypical subtrochanteric fracture. Based on the current situation, research for new drugs to regulate bone resorption remains relevant. MicroRNAs (miRNAs) are a new group of small, noncoding RNAs of 19–25 nucleotides, which negatively regulate gene expression after transcription. Recent studies discovered miRNAs play a considerable function in bone remodeling by regulating osteoblast and osteoclast differentiation and function. An increasing number of miRNAs have been identified to participate in osteoclast formation, differentiation, apoptosis, and resorption. miRNAs show great promise to serve as biomarkers and potential therapeutic targets for osteoporosis. In this review, we will summarize our current understanding of how miRNAs regulate osteoclastogenesis and function. We will further discuss the approach to develop drugs for osteoporosis based on these miRNA networks.

Total Hip Arthroplasty for Implant Rupture after Surgery for Atypical Subtrochanteric Femoral Fracture.

Treatment methods for delayed union and nonunion of atypical femoral fracture are still controversial. Moreover, no treatment method has been established for implant rupture caused by delayed union and nonunion. We encountered a 74-year-old female in whom nonunion-induced implant rupture occurred after treatment of atypical subtrochanteric femoral fracture with internal fixation using a long femoral nail. It was unlikely that sufficient fixation could be obtained by repeating osteosynthesis alone. Moreover, the patient was elderly and early weight-bearing activity was essential for early recovery of ADL. Based on these reasons, we selected one-stage surgery with total hip arthroplasty and osteosynthesis with inverted condylar locking plate as salvage procedures. Bone union was achieved at 6 months after surgery. This case illustrated that osteosynthesis-combined one-staged total hip arthroplasty could be considered as one of the options for nonunion-induced implant rupture of atypical femoral subtrochanteric fracture.

Atypical fractures of the femur: effect of anterolateral bowing of the femur on fracture location.

Bisphosphonate therapy has been associated with the development of atypical femoral fractures. The most common sites of bisphosphonate-associated fractures are at the subtrochanteric region followed by the femoral shaft. This retrospective study hypothesizes that increasing anterolateral femoral bow is associated with more distal diaphyseal fractures. Awareness of this relationship is essential in the pre-operative planning and successful surgical management of these fractures. We retrospectively reviewed twenty-one atypical subtrochanteric and femoral diaphyseal fractures and stress reactions within a 5-year period at our institution. Radiographs were assessed by two independent investigators for the degree of anterior and lateral femoral bow, and how distal the fracture was from the lesser trochanter. The relationship between the fracture position or stress reaction and degree of anterior and lateral bowing was analysed. There was a statistically significant linear relationship between anterior and lateral femoral bowing, and the fracture position along the diaphysis (correlation coefficient 0.63 (p = 0.002) and 0.684 (p = 0.001), respectively). Inter-observer reliability was highly correlated (Kappa value >0.8). In atypical femoral fractures associated with bisphosphonate use, more distal diaphyseal fractures occurred with a higher degree of anterior and lateral femoral bow.

Atypical Femur Fractures Associated With Diphosphonate Use.

Osteoporosis-related fractures create a heavy economic and healthcare burden. Although diphosphonate medications have been successful at decreasing the risk of osteoporotic fragility fractures and have become staples in the treatment of osteoporosis, concerns have been raised about the association of diphosphonate therapy with spontaneous nonvertebral fractures. Diphosphonate fractures are characteristically transverse or slightly oblique in nature and occur in the lateral cortex, or tension side, of the subtrochanteric region of the femur where diffuse cortical thickening and fracture can be observed on radiographs. A multidisciplinary approach incorporating both medical and surgical teams should be used in the case of diphosphonate-associated fractures. Future medical and surgical developments that augment fracture fixation and counteract diphosphonate-associated osteoclast apoptosis may play a role in therapy. Although diphosphonate use has decreased the rate of osteoporosis-related fractures, increased awareness and association with atypical subtrochanteric fractures is an important concern for clinicians to keep in mind.

Proximal Femoral Fractures: What the Orthopedic Surgeon Wants to Know.

Each year, more than 250,000 hip fractures occur in the United States, resulting in considerable patient mortality and morbidity. The various types of adult proximal femoral fractures require different treatment strategies that depend on a variety of considerations, including the location, morphologic features, injury mechanism, and stability of the fracture, as well as the patient's age and baseline functional status. The authors discuss femoral head, femoral neck, intertrochanteric, and subtrochanteric fractures in terms of injury mechanisms, specific anatomic and biomechanical features, and important diagnostic and management considerations, including the diagnostic utility of imaging modalities. The authors review clinically important classification systems, such as the Pipkin, Garden, Pauwels, and Evans-Jensen classification systems, with emphasis on differentiating subchondral insufficiency fractures from avascular necrosis of the femoral head and typical subtrochanteric fractures from atypical (often bisphosphonate-related) subtrochanteric fractures. In addition, the authors describe the potential complications and management strategies for each fracture type on the basis of the patient's age and physical condition. A clear understanding of these considerations allows the radiologist to better provide appropriate and relevant diagnostic information and management guidance to the orthopedic surgeon.