Case reports: subtrochanteric femoral stress fractures after prolonged alendronate therapy

Bisphosphonate-Related Atypical Femoral Fractures in Patients with Autoimmune Disease Treated with Glucocorticoids: Surgical Results for 20 Limbs

BACKGROUND

Glucocorticoids induce osteoporosis, while bisphosphonates treat it, yet both can lead to atypical femoral fractures. Patients on both agents may face challenges in healing from such fractures due to their pathophysiology and pharmacological effects.

METHODS

Intramedullary nail surgery was performed on 20 limbs in 19 patients with atypical femoral fractures and autoimmune diseases, who had received bisphosphonates for GC-induced osteoporosis. The average durations of glucocorticoid and bisphosphonate use were 17 and 9 years (standard deviation: 7.59 and 4.35), respectively, and the mean follow-up period was 66 months. Fifteen and five limbs were fractured at the subtrochanter and diaphysis, respectively. The surgical techniques (type of nail) and additional procedures performed in these cases were examined. The post-operative alignment and reduction status on radiographs were examined to determine their relationship with post-operative outcomes.

RESULTS

Cephalomedullary long nails were inserted in nine limbs and antegrade intramedullary nails in 11 limbs. As an additional surgical procedure, open reduction, bone grafting and drilling were carried out on six, two, and five limbs, respectively. Regarding malalignment on radiographs, AP images showed varus in four limbs, and lateral images showed extension in two limbs. Regarding the cortical discontinuity, the distal fragment of the 11th limb shifted posteriorly in the lateral view. Gaps at the fracture sites were observed in 11 limbs. As a result, bone union was confirmed in 13 limbs. Five of the seven nonunion limbs required additional surgery. When comparing union and nonunion, open reduction and drilling were involved in nonunion limbs.

CONCLUSION

The surgical outcomes of atypical femoral fractures in patients with autoimmune disease and on long-term glucocorticoids and bisphosphonates were poor. Although it is not possible to affirm for sure based on these results alone, management with prophylactic surgery before complete fracture is considered to be required to improve outcomes.

An osteoporosis bone defect regeneration strategy via three-dimension short fibers loaded with alendronate modified hydroxyapatite

Osteoporotic bone defect has become clinic challenge due to its morbid bone microenvironment. Overactive bone resorption and limited bone formation lead to unstable combination between bone tissue and scaffolds. Electrospinning has been widely used in guide tissue membrane, but its barrier property results in limited application. In order to optimize the structure and add anti-bone resorption function of electrospinning fibers, we exploited the application of short fibers generated by homogenization at osteoporotic tibial bone defect. The modified nano-hydroxyapatite (m-HA) was loaded with alendronate. It overcame the problem that hydrophilic drugs were difficult to distribute uniformly in hydrophobic fibers. We confirmed that m-HA was loaded into polycaprolactone (PCL) short fibers. PCL short fibers with m-HA (PCL/m-HA) continuously released ALN, provided stable structure and showed good cytocompatibility. In vitro, PCL/m-HA increased the activity of alkaline phosphatase (ALP), promoted extracellular matrix mineralization and upregulated the expression of osteogenesis-related genes, Col 1, Alp, osteopontin (Opn) and runt-related transcription factor 2 (Runx2). In vivo, PCL/m-HA short fibers accelerated the new bone formation, inhibited the bone resorption and rebalanced the bone microenvironment through regulating osteoprotegerin (OPG) /receptor activator of NF-kB (RANKL) ratio. The above results confirmed that the PCL/m-HA short fibers achieved the application of three-dimension osteoporotic bone defect and had potential prospects in bone tissue scaffolds.

Current concepts in the management of bisphosphonate associated atypical femoral fractures

Bisphosphonates are a class of drugs used as the mainstay of treatment for osteoporosis. Bisphosphonates function by binding to hydroxyapatite, and subsequently targeting osteoclasts by altering their ability to resorb and remodel bone. Whilst aiming to reduce the risk of fragility fractures, bisphosphonates have been associated with atypical insufficiency fractures, specifically in the femur. Atypical femoral fractures occur distal to the lesser trochanter, until the supracondylar flare. There are a number of the differing clinical and radiological features between atypical femoral fractures and osteoporotic femoral fractures, indicating that there is a distinct difference in the respective underlying pathophysiology. At the point of presentation of an atypical femoral fracture, bisphosphonate should be discontinued. This is due to the proposed inhibition of osteoclasts and apoptosis, resulting in impaired callus healing. Conservative management consists primarily of cessation of bisphosphonate therapy and partial weightbearing activity. Nutritional deficiencies should be investigated and appropriately corrected, most notably dietary calcium and vitamin D. Currently there is no established treatment guidelines for either complete or incomplete fractures. There is agreement in the literature that nonoperative management of bisphosphonate-associated femoral fractures conveys poor outcomes. Currently, the favoured methods of surgical fixation are cephalomedullary nailing and plate fixation. Newer techniques advocate the use of both modalities as it gives the plate advantage of best reducing the fracture and compressing the lateral cortex, with the support of the intramedullary nail to stabilise an atypical fracture with increased ability to load-share, and a reduced bending moment across the fracture site. The evidence suggests that cephalomedullary nailing of the fracture has lower revision rates. However, it is important to appreciate that the anatomical location and patient factors may not always allow for this. Although causation between bisphosphonates and atypical fractures is yet to be demonstrated, there is a growing evidence base to suggest a higher incidence to atypical femoral fractures in patients who take bisphosphonates. As we encounter a growing co-morbid elderly population, the prevalence of this fracture-type will likely increase. Therefore, it is imperative clinicians continue to be attentive of atypical femoral fractures and treat them effectively.

Histopathological Finding of Microdamage Accumulation in Atypical Subtrochanteric Femoral Fracture

Atypical femoral fracture is a low-energy stress fracture in the subtrochanteric region or the femoral shaft and is a complication of the long-term use of bisphosphonates. Histopathological findings of atypical femoral fractures have not been clarified. Herein, we report the case of a 61-year-old woman who fell while walking, which prompted her to visit our facility. She had a 7-year history of alendronate use to treat osteoporosis. A radiograph showed an atypical subtrochanteric femoral fracture, following which she underwent a primary surgery, where an intramedullary femoral nail was used. Implant breakage was discovered 8 weeks after the primary surgery. The patient underwent a revision surgery in which the entry point for the revised intramedullary hole was created to prevent varus position. The lag screw was successfully inserted into the center of the femoral head. Cancellous bone, isolated from the right ilium, was autogenously implanted into the fracture site. Fracture healing was promoted using low-intensity pulse ultrasonography. Callus formation was detected on a radiograph, and full weight-bearing was advised 12 weeks after the revision surgery. The fracture had healed completely at 13 months after the revision surgery. The patient was able to walk without support and could independently perform activities of daily life. Laboratory findings suggested that the concentrations of her bone formation markers were normal, while those of bone resorption markers were elevated. Iliac bone histomorphometry did not reveal severely suppressed bone turnover. In the cortex of fracture site, the lacunar density was markedly lower than the osteocyte density, and microcracks were detected, suggesting impaired osteocyte function and a low potential for fracture healing. This case is notable because it helps to clarify the histopathological findings of atypical femoral fractures.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

Atypical femoral fractures related to bisphosphonate treatment: issues and controversies related to their surgical management

AIMS

Treatment guidelines for atypical femoral fractures associated with bisphosphonates have not been established. We conducted a systematic review of the treatment of atypical femoral fractures first, to evaluate the outcomes of surgical fixation of complete atypical fractures and secondly, to assess whether prophylactic surgery is necessary for incomplete atypical fractures.

MATERIALS AND METHODS

Case reports and series were identified from the PubMed database and were included if they described the treatment of atypical femoral fractures. In total, 77 publications met our inclusion criteria and 733 patients with 834 atypical complete or incomplete femoral fractures were identified.

RESULTS

For complete fractures, internal fixation was predominantly achieved by intramedullary nailing. The mean time to healing post-operatively was 7.3 months (2 to 31). Revision surgery for nonunion or implant failure was needed in 77 fractures (12.6%). A greater percentage of fractures treated with plate fixation (31.3%) required revision surgery than those treated with intramedullary nailing (12.9%) (p < 0.01). Non-operative treatment of incomplete fractures failed and surgery was eventually needed in nearly half of the patients (47%), whereas prophylactic surgery was successful and achieved a 97% rate of healing.

CONCLUSION

Intramedullary nailing is the first-line treatment for a complete fracture, although the risk of delayed healing and revision surgery seems to be higher than with a typical femoral fracture. Non-operative treatment does not appear to be a reliable way of treating an incomplete fracture: prophylactic intramedullary nailing should be considered if the patient is in intractable pain. Radiographs of the opposite side should be obtained routinely looking for an asymptomatic fracture. Bisphosphonates must be discontinued but ongoing metabolic management in the form of calcium and/or vitamin D supplements is advisable. Teriparatide therapy can be considered as an alternative treatment. Cite this article: Bone Joint J 2017;99-B:295-302.

Simultaneous, bilateral, complete atypical femoral fractures after long-term alendronate use

Over the past decade there have been increasing reports of atypical femoral fractures (AFFs) associated with bisphosphonate use. Reported cases of bilateral involvement usually refer to sequential injuries, or a complete fracture with an incomplete injury to the contralateral limb. In this case report we describe simultaneous, bilateral, complete atypical femoral fractures following a simple fall. A history of prodromal pain, previous radiological evidence of cortical thickening and long term alendronate therapy for osteoporosis secondary to corticosteroid treatment paint a classical picture of the presentation of an atypical fracture pattern of which orthopaedic surgeons should be aware.

Pamidronate Treatment to Prevent Reoccurring Fractures in Children With Cerebral Palsy

BACKGROUND

Some children with cerebral palsy (CP) have frequent fractures due to low bone mineral density and receive treatment with pamidronate, an intravenous bisphosphonate. Our review evaluates the outcome of pamidronate treatment in these children.

METHODS

A retrospective chart review was performed, and 32 patients (14 girls and 18 boys) with CP Gross Motor Function Classification System level III (2 patients), IV (3 patients), and V (27 patients) treated with 5 courses of pamidronate for low mineral density were identified. Patients with a minimum of 2 years of follow-up were included in the study. Data collection was a review of the demographics and pretreatment, peritreatment, and posttreatment fracture history.

RESULTS

The mean age at treatment was 11.6 years (range, 2.9 to 19.6 y). There were 102 fractures (mean duration 2.5 y) pretreatment and 28 fractures posttreatment. With an average follow-up of 6.4 years, posttreatment rate of fracture decreased to 0.10 fractures per year from the pretreatment rate of 2.4 fractures per year (P<0.001). The femur was the most common bone fractured both pretreatment (54%) and posttreatment (61%); the major site was the distal third of the femur. There were 11 fractures during the course of pamidronate treatment at a rate of 0.33 fractures per year. Only 11 patients (34%) sustained fracture posttreatment. No correlation with fracture pattern or occurrence was found with patient age, number of pretreatment fractures, or sex. Most fractures were caused by low-energy injuries, and most were managed nonoperatively.

CONCLUSIONS

In patients with CP and disuse osteoporosis, the most common fracture sustained involved the distal femur via low-velocity injury, and most fractures were treated nonoperatively. Although the fracture pattern and the treatment remained unchanged, reoccurring fractures in these children can be effectively treated medically to interrupt the fracturing tendency.

Applying low-intensity pulsed ultrasounds (LIPUS) to a zoledronate-associated atypical femoral shaft fracture without cessation of zoledronate therapy for 3 years follow up: a case report

Reports are increasing regarding atypical femoral fractures (AFFs) caused by minor trauma in patients using bisphosphonates (BPs) for long periods. Patients with malignant skeletal metastases potentially are at greater risk for these AFFs, especially considering the high dose and the duration of treatment with BPs. We evaluated a case of atypical femoral shaft fracture treated with an intramedullary nail in a patient treated for five years with zoledronate who had breast cancer with metastases to bone. Although bone union was achieved without cessation of zoledronate therapy by applying low-intensity pulsed ultrasounds (LIPUS), the remodeling phase of the fracture healing process was delayed. For BPs-associated AFFs, LIPUS is an alternative to parathyroid hormone (PTH) analogs such as teriparatide that are contraindicated in patients with malignant skeletal metastases. LIPUS is an effective treatment for fracture healing and may avoid the necessity to discontinue BP therapy.

Association between alendronate and atypical femur fractures: a meta-analysis

Alendronate (ALN) is a commonly used drug for the treatment of osteoporosis. Atypical femur fractures (AFFs) have been associated with long-term use of ALN and have recently become the subject of considerable attention as ALN use increases. This meta-analysis aimed to determine the relationship between ALN and AFF. The Embase, PubMed, and Cochrane library databases were searched for relevant studies published before November 6, 2014. Studies clearly reporting the relationship between ALN and AFF were selected for our analysis. From these results, the relationship between ALN and AFF was analyzed. Weighted mean differences were calculated using a random-effects model. Five studies were included in this meta-analysis. The results revealed that the use of ALN will not increase the risk of AFF in short term (P>0.05), but there will be a risk of AFF (P<0.05) with long-term (>5 years) use of ALN. These findings indicate that long-term use of ALN is a risk factor for AFF and that more attention should be paid to the clinical applications of ALN.

Spontaneous acetabular periprosthetic fracture in a patient continuously having zoledronic acid

Zoledronic acid has been used for prevention of osteolytic and osteoblastic bone metastasis. This case report illustrates an undesirable consequence from prolonged usage of zoledronic acid in bone metastasis prevention. Periprosthetic acetabular fracture in a patient treated with zoledronic acid for 7 years was reported. The clinical presentation, radiographic and pathological results were described. This is a rare complication after total hip arthroplasty which should not be ignored especially in patients who received long term bisphosphonate.

Symptomatic atypical femoral fractures are related to underlying hip geometry

The benefits of bisphosphonates are well documented, but prolonged use has been associated with atypical femur fractures. Radiographic markers for fracture predisposition could potentially aid in safer medication use. In this case-control designed study, we compared hip radiographic parameters and the demographic characteristics of chronic bisphosphonate users who sustained an atypical femoral fracture with a group of chronic bisphosphonate users who did not sustain an atypical femur fracture and also a group who sustained an intertrochanteric hip fracture. Radiographic parameters included were neck-shaft angle (NSA), hip-axis length (HAL) and center-edge angle (CE). Multivariate regression was used to evaluate the relationship between radiographic measures and femur fracture. Receiver-operating characteristic analysis determined cut-off points for neck-shaft angle and risk of atypical femur fracture. Ultimately, pre-fracture radiographs of 53 bisphosphonate users who developed atypical fracture were compared with 43 asymptomatic chronic bisphosphonate users and 64 intertrochanteric fracture patients. Duration of bisphosphonate use did not statistically differ between users sustaining atypical fracture and those without fracture (7.9 [±3.5] vs. 7.7 [±3.3] years, p=0.7). Bisphosphonate users who fractured had acute/varus pre-fracture neck-shaft angles (p<0.001), shorter hip-axis length (p<0.01), and narrower center-edge angles (p<0.01). Regression analysis revealed associations between neck-shaft angle (OR=0.89 [95% CI=0.81-0.97; p=0.01), center edge angle (OR=0.89 [95% CI=0.80-0.99]; p=0.03), and BMI (OR=1.15 [95% CI=1.02-1.31; p=0.03) with fracture development. ROC curve analysis (AUC=0.67 [95% CI=0.56-0.79]) determined that a cut-off point for neck-shaft angle <128.3° yielded 69% sensitivity and 63% specificity for development of atypical femoral fracture. Ultimately, an acute/varus angle of the femoral neck, high BMI, and narrow center-edge angle were associated with development of atypical femur fracture in long-term bisphosphonate users. Patients on long-term bisphosphonates should be regularly radiographically evaluated in order to assess for potential risk of atypical fracture.

Atypical bilateral stress fractures of the femoral shaft diagnosed by bone scintigraphy in a woman with osteoporosis

Recent case series have identified the presence of atypical insufficiency fractures at the diaphyseal femur of osteoporotic patients, which are possibly related to the long-term use of biphosphonates. We present images of a 72-year-old woman with a history of colon cancer and osteoporosis referred for bone scintigraphy because of bilateral thigh pain. No trauma or intense exercise was reported. Bone scan revealed bilateral femoral shaft stress fractures, which were confirmed by plain radiographs. In oncologic patients with osteoporosis referred for bone scintigraphy, atypical stress fractures should be included in the differential diagnosis of focal findings in the diaphyseal femur.

Propagation of bisphosphonate-related femoral stress fractures despite femoral nailing: a cautionary tale from 2 cases

We report 2 cases of atypical femoral fracture displacement despite treatment with intramedullary (IM) nailing. Both patients had received more than 3 years of bisphosphonates. One patient had prophylactic fixation of an atypical femur fracture due to intractable pain. The other had undergone nailing previously for a traumatic shaft fracture. The patient then received bisphosphonate later and sustained an atypical fracture with the nail in place. Both femoral nails were slotted, cannulated stainless steel piriformis entry designs. These 2 cases are among the first reported failures of IM fixation in preventing displacement of a bisphosphonate stress fracture. We advice caution when using slotted nails in prophylaxis of atypical femur fractures because of its significantly reduced torsional stiffness compared to modern nonopen sectioned nails.

Atypical subtrochanteric and diaphyseal femoral fractures: second report of a task force of the American Society for Bone and Mineral Research

Bisphosphonates (BPs) and denosumab reduce the risk of spine and nonspine fractures. Atypical femur fractures (AFFs) located in the subtrochanteric region and diaphysis of the femur have been reported in patients taking BPs and in patients on denosumab, but they also occur in patients with no exposure to these drugs. In this report, we review studies on the epidemiology, pathogenesis, and medical management of AFFs, published since 2010. This newer evidence suggests that AFFs are stress or insufficiency fractures. The original case definition was revised to highlight radiographic features that distinguish AFFs from ordinary osteoporotic femoral diaphyseal fractures and to provide guidance on the importance of their transverse orientation. The requirement that fractures be noncomminuted was relaxed to include minimal comminution. The periosteal stress reaction at the fracture site was changed from a minor to a major feature. The association with specific diseases and drug exposures was removed from the minor features, because it was considered that these associations should be sought rather than be included in the case definition. Studies with radiographic review consistently report significant associations between AFFs and BP use, although the strength of associations and magnitude of effect vary. Although the relative risk of patients with AFFs taking BPs is high, the absolute risk of AFFs in patients on BPs is low, ranging from 3.2 to 50 cases per 100,000 person-years. However, long-term use may be associated with higher risk (∼100 per 100,000 person-years). BPs localize in areas that are developing stress fractures; suppression of targeted intracortical remodeling at the site of an AFF could impair the processes by which stress fractures normally heal. When BPs are stopped, risk of an AFF may decline. Lower limb geometry and Asian ethnicity may contribute to the risk of AFFs. There is inconsistent evidence that teriparatide may advance healing of AFFs.

Atypical incomplete femoral fractures in asymptomatic patients on long term bisphosphonate therapy

OBJECTIVES

Progression of an incomplete atypical femoral fracture (IF) to a complete fracture in patients on long term bisphosphonate (BP) therapy can be catastrophic. We aimed to determine the frequency and imaging features of IF in asymptomatic patients on long-term BP therapy and to identify distinguishing clinical and laboratory markers in the subset of patients who develop these fractures.

MATERIAL AND METHODS

From August 2009 to March 2011, 220 femoral radiographs in 110 asymptomatic patients (101 women, 9 men, age 47-94) were reviewed by 2 radiologists. All patients were on BP therapy for at least 3 years and had no history of hip/thigh pain or recent trauma. MRI was performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, 25-hydroxy vitamin D, intact parathyroid hormone, serum c-telopeptide and urine n-telopeptide were obtained in all patients.

RESULTS

Two of 110 patients (1.82%, confidence interval of 0.6% to 6.3%) had 3 IFs. Both patients, age 50 and 57, were Caucasian, active and on BP for 8 years. MRI confirmed radiographic findings in both patients. Both women had T-scores in the osteopenic range at 2 sites and osteoporotic range at 1 site.

CONCLUSION

The 1.82% frequency of IF in asymptomatic patients on long term BP therapy is higher than that suggested in the literature. Statistical differences between fracture and non-fracture groups were not presented as the patient population was too small to draw any significant conclusions.

Surgical treatment improves clinical and functional outcomes for patients who sustain incomplete bisphosphonate-related femur fractures

OBJECTIVE

To describe the outcomes for patients treated at a single institution, who sustained incomplete bisphosphonate-induced femoral fractures.

DESIGN

Retrospective review.

SETTING

University-based academic medical center.

PATIENTS

Thirty-one patients with 43 incomplete fractures met the inclusion criteria.

INTERVENTION

Nonoperative management or surgical intervention for fractures with refractory symptoms or progression of fracture lucency on radiographs.

MAIN OUTCOME MEASUREMENTS

Radiographic assessments and the Short Musculoskeletal Functional Assessment to gauge functional status.

RESULTS

The cohort was all women with an average age of 69.2 (range: 46-92) years and had been treated with bisphosphonate therapy for an average of 9.1 (range: 5-20) years. The average healing time for all incomplete fractures was 9.4 (range: 1.5-36) months. Forty-nine percent of the fractures (21 of 43 fractures) were ultimately treated with surgery for impending complete fracture or failure of nonsurgical management. Of the incomplete fractures treated with surgery, 81% became pain free and 100% were radiographically healed at a mean of 7.1 (range: 1.5-12) months. In contrast, of the nonoperatively treated incomplete fractures, only 64% were pain free at latest follow-up, with only 18% of fractures demonstrating radiographic evidence of healing at an average of 11 (range: 6-24) months. Standardized dysfunction index from the Short Musculoskeletal Functional Assessment was better (19.7) in the surgical group than in the nonsurgical group (19.7 vs. 25.7, P = 0.0017).

CONCLUSIONS

A higher percentage of patients treated surgically became asymptomatic and demonstrated radiographic evidence of healing earlier than those treated nonsurgically. Surgical intervention is effective for relief of symptoms when treating incomplete bisphosphonate-related femur fractures, and patients should be counseled to the potential benefits of prophylactic surgery.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

[What do we know about atypical fractures in patients on biphosphonates treatment? A literature review using a case series]

AIM

Retrospective review of long term biphosphonates treated patients who sustained a subtrochanteric or diaphyseal femoral fracture with an atypical pattern. A literature review is presented as an update of the topic.

MATERIAL AND METHODS

A retrospective study was conducted on 13 subtrochanteric or diaphyseal fractures in female patients treated with biphosphonates at our institution from September 2007 to March 2011.

RESULTS

Four cases of subtrochanteric fractures and 13 diaphyseal fractures were detected. Four patients had bilateral fractures. All cases but one (that affected only the lateral cortex) were complete fractures. Surgically, these kinds of fractures are demanding due to the hardness of the bones.

DISCUSSION

It is difficult to know if there is any relationship between bisphosphonates treatment and atypical femoral fractures. Nevertheless, current literature supports a greater benefit of their use in preventing vertebral and non-vertebral fractures. For this reason, biphosphonates continue being considered as a first choice in the prevention of osteoporotic fractures.

CONCLUSIONS

Patients on long-term treatment with bisphosphonates may present atypical femoral fractures as a complication. It is considered that the maximum period for biphosphonates treatment should not exceed 5 years.

Atypical femoral fracture after long-term alendronate treatment: report of a case evidenced with magnetic resonance imaging

Postmenopausal osteoporosis is commonly treated with alendronate, one of the bisphosphonates used for the prevention and treatment of osteoporotic fractures. However, the correlation between atypical femoral fractures and long-term bisphosphonate therapy has not been clearly identified. We report here the case of a 69-year-old woman with postmenopausal osteoporosis who presented with an atypical femoral subtrochanteric fracture on magnetic resonance imaging (MRI) confirmation after having received alendronate therapy for about 3 years. The fracture united after refixation and after administration of alendronate was stopped. Several published reports were reviewed, and some clinical characteristics of this atraumatic fracture were revealed, including the clinical symptoms of thigh pain, stress reaction or stress fracture, and transverse fracture with unicortical beak in an area of cortical hypertrophy. In addition to a regular radiographic survey, MRI, which may provide early information, and bone biopsy for pathologic analysis may be used as tools for early detection and final diagnosis. Once an insufficiency fracture is suspected or proved to be related to bisphosphonate, the withholding of bisphosphonate should be highly recommended to enhance fracture healing. Prophylactic fixation should be considered if fracture healing is not good or if the patient cannot tolerate protection of weight-bearing.

Bisphosphonate-associated femur fractures have high complication rates with operative fixation

BACKGROUND

Bisphosphonate-associated femur fractures have been well described but the preoperative patient factors, treatment modalities, and complications of treatment are unclear.

QUESTIONS/PURPOSES

We asked whether a diagnosis of osteoporosis, the characteristic radiographic features of bisphosphonate-related femur fractures, and complication rates differed in patients with operatively treated femoral shaft fractures receiving bisphosphonates and in patients not receiving bisphosphonates.

METHODS

We retrospectively reviewed 43 patients with bisphosphonate-associated femoral shaft fractures (including subtrochanteric) from 2002 to 2008 and 20 patients with similar fractures but not treated with bisphosphonates. Similar implants were used in both groups, but a greater number of adjuvants were used in the bisphosphonate cohort. We recorded preoperative osteoporosis and radiographic findings of the characteristic bisphosphonate femur fracture and early complications. The minimum followup was 5 months (mean, 29 months; range 5-60 months).

RESULTS

Preoperatively a greater percentage of patients treated with bisphosphonates had confirmed osteoporosis than those not treated with bisphosphonates (24% versus 5%, respectively), a greater percentage had a proximal fracture location (48% versus 40%, respectively), and their mean cortex to shaft diameter ratio was greater (24% versus 15%, respectively). The bisphosphonate cohort had a higher rate of intraoperative fractures (21% versus 0%) and postoperative plate failures (30% versus 0%).

CONCLUSIONS

Despite low rates of other risk factors and ample use of biologic adjuvants, patients treated with bisphosphonates having femur fractures have more complications.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Frequency of incomplete atypical femoral fractures in asymptomatic patients on long-term bisphosphonate therapy

OBJECTIVE

The purpose of our study was to determine the frequency and imaging features of atypical femoral fractures in a consecutive asymptomatic patient population on long-term bisphosphonate treatment and search for distinguishing clinical and laboratory parameters in the subset of patients with fractures.

SUBJECTS AND METHODS

Two hundred femoral radiographs in 100 asymptomatic patients (93 women and seven men; age range, 47-94 years; mean age, 69.3 years) were prospectively reviewed by two radiologists. All patients had received bisphosphonate treatment for at least 3 years and had no history of pain or recent trauma. MRI studies were performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, albumin, 25-hydroxy vitamin D, intact parathyroid hormone (iPTH), serum C-telopeptide, and urine N-telopeptide values were obtained.

RESULTS

Two of 100 patients (2%) had three insufficiency fractures. Both patients, 50 and 57 years old, were white, active, and had been receiving bisphosphonate therapy for 8 years. The patient with bilateral atypical femoral fractures showed typical features of bisphosphonate-related incomplete atypical femoral fractures. MRI confirmed the radiographic findings in both patients. The two patients with incomplete atypical femoral fractures were significantly younger than those without atypical femoral fractures. There were no significant differences among the fracture and nonfracture groups in terms of clinical or laboratory results, except for mean iPTH, which was significantly decreased in the fracture group.

CONCLUSION

The 2% frequency of incomplete atypical femoral fractures in asymptomatic patients on long-term bisphosphonate therapy is higher than suggested in the literature. Aside from age and mean iPTH, there were no significant differences in clinical or laboratory data between the two groups.

Management strategy for symptomatic bisphosphonate-associated incomplete atypical femoral fractures

BACKGROUND

Long-term bisphosphonate use has often been associated with atypical femoral fractures. These fractures evolve from incomplete femoral fractures. A previous study demonstrated that the presence of a radiolucent line in an incomplete fracture can indicate a high risk of progression to complete fracture.

QUESTIONS/PURPOSES

The aim of this study is to present a management strategy for symptomatic bisphosphonate-associated incomplete atypical femoral fractures. Specific study questions include the following: (1) Is there a difference in the prognosis of these fractures based on the presence or absence of a radiolucent fracture line? (2) Can treatment with teriparatide assist in clinical/radiographic healing of these incomplete fractures? (3) Is there a characteristic biochemical profile in these patients?

PATIENTS AND METHODS

We retrospectively examined all femur radiographs ordered by the metabolic bone disease service at our hospital between July 1, 2006 and July 1, 2011 and identified 10 patients with a total of 14 incomplete fractures. Nine patients received bisphosphonates for a mean duration of 10 ± 5 years (range, 4-17). The mean follow-up since the time of diagnosis was 20 ± 11 months (range, 6-36 months).

RESULTS

Five fractures did not have a radiolucent fracture line and were treated conservatively with partial weight-bearing restrictions and pharmacologic therapy. All five of these fractures healed with conservative management. Nine fractures had a radiolucent fracture line, and only two of these were treated successfully with conservative management including teriparatide. Six of the eight patients with a radiolucent line elected for surgical prophylaxis after 3 months of conservative management, whereas one patient underwent surgical prophylaxis without a trial of conservative management. Regarding the biochemical profiles, bone turnover markers for our patient cohort were in the lower quartile.

CONCLUSIONS

Fractures without a radiolucent line appear to respond to conservative management and not require surgical prophylaxis. Teriparatide treatment may hold promise in promoting healing of these fractures.

Femoral fractures in osteoporotic patients on bisphosphonates. A case report

Osteoporotic fractures and particularly hip fractures represent a considerable burden of illness in the elderly. Bisphosphonates (BP) have been used extensively over the past decade and a half for the management of osteoporosis with considerable clinical benefit in the reduction of fragility fractures. Although not apparent in clinical trials, rare associations of subtrochanteric atypical femoral fractures (AFF) have been reported postmarketing, often after long-term BP therapy. Here, we report a well-characterized Asian female patient with bilateral AFF after long-term etidronate and alendronate therapy.

Femoral stress fractures associated with long-term bisphosphonate treatment

BACKGROUND

Recent studies have described unique clinical and radiographic characteristics of femoral stress fractures or low-energy fractures associated with long-term bisphosphonate therapy. However, it is unclear whether these fractures require subsequent surgery after the initial treatment.

QUESTIONS/PURPOSES

We performed a cohort analysis of bisphosphonate-associated femoral stress fractures to (1) confirm the unique clinical and radiographic findings compared with existing literature, (2) determine whether any patients with completed fractures had no preexisting transverse stress fracture lines, (3) assess the need for additional surgical procedures, and (4) determine whether the hospital length of stay (LOS) differed for patients with prophylactic fixation of stress fractures versus fixation of completed fractures.

METHODS

We retrospectively reviewed 16 patients with 24 diaphyseal and subtrochanteric femoral stress fractures (14) or low-energy fractures (10) who had been on bisphosphonates for 3 to 10 years. Data included demographics, symptoms, medication history, radiographic characteristics, treatment parameters, LOS, and outcome. Minimum followup was 9 months (average, 44.0 months; median, 31 months; range, 9-112 months).

RESULTS

All patients had clinical and radiographic findings similar to those reported in the literature. Two of four patients sustained completed fractures after radiographs failed to reveal transverse lateral fracture lines. None of the 14 prophylactically treated impending fractures progressed or required additional surgery; however, in five of 10 femurs treated after fracture completion, six additional surgeries were performed. The average hospital LOS was shorter in patients who underwent prophylactic fixation (3.8 days) than in patients treated for completed fractures (5.6 days).

CONCLUSIONS

Bisphosphonate-associated stress fractures and completed fractures are unique, possessing subtle characteristic radiographic features. Completed fractures may occur through the thickened bone in the absence of an appreciable transverse stress fracture line. Our observations suggest prophylactic reconstruction nail fixation may avoid fracture completion and may be associated with a shorter hospital LOS and less morbidity than treatment of completed fractures.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Periprosthetic Femoral Insufficiency Fracture in a Patient on Long-term Bisphosphonate Therapy

Recent literature shows an association between long-term bisphosphonate therapy and low-energy fractures of the subtrochanteric femur. It is thought that the pharmacology of bisphosphonates and stress characteristics of the sub-trochanteric femur predispose patients on long-term therapy to fracture. There are few reports in the literature of bisphos-phonate-associated periprosthetic fractures with the characteristic fracture pattern. We report a case in a patient with a 10- year history of sustained bisphosphonate use. The patient is a 79-year-old female that developed new thigh pain 9 years following a cemented total hip arthroplasty. Radiographs revealed lateral cortical thickening and a transverse periprosthetic stress fracture of the lateral femoral cortex at the level of the distal stem. This fracture appears consistent with a bisphosphonate-associated insufficiency fracture, demonstrating that this pattern is not isolated to nonarthroplasty patients.

Schaeffer JF, Attarian DE, Wellman SS. Periprosthetic Femoral Insufficiency Fracture in a Patient on Long-term Bisphosphonate Therapy. The Duke Orthop J 2012;2(1):66-69.

Atypical bilateral pedicle fracture in long-term bisphosphonate therapy

STUDY DESIGN

A case report with review of the literature.

OBJECTIVE

To present a first case of an atraumatic bilateral pedicle fracture of L5 in a patient with long-term risedronate therapy and without any previous history of surgery or fracture.

SUMMARY OF BACKGROUND DATA

A few cases of bilateral osteoporotic pedicle fractures have been reported. All were associated with previous or concomitant corporeal compression fractures. Atypical femoral fractures were recently described with long-term bisphosphonate treatment. To our knowledge, there are no previous reports of isolated bilateral pedicle fracture associated with prolonged bisphosphonate therapy.

METHODS

A 66-year-old woman treated with risedronate for 10 years and without any history of trauma presented with exacerbation of low back pain. No fracture was noted in her past medical history.

RESULTS

A complete workup showed an isolated bilateral recent fracture of the L5 pedicles without evident etiology. Consolidation was achieved after 3 months of bracing.

CONCLUSION

We reported the first case of isolated bilateral pedicle fracture in a patient treated with risedronate for 10 years. This may be another atypical fracture in long-term bisphosphonate treatment.

Bisphosphonate-related complete atypical subtrochanteric femoral fractures: diagnostic utility of radiography

OBJECTIVE

The objective of our study was to evaluate the diagnostic utility of conventional radiography for diagnosing bisphosphonate-related atypical subtrochanteric femoral fractures.

MATERIALS AND METHODS

Retrospective interpretation of 38 radiographs of complete subtrochanteric and diaphyseal femoral fractures in two patient groups-one group being treated with bisphosphonates (19 fractures in 17 patients) and a second group not being treated with bisphosphonates (19 fractures in 19 patients)-was performed by three radiologists. The readers assessed four imaging criteria: focal lateral cortical thickening, transverse fracture, medial femoral spike, and fracture comminution. The odds ratios and the sensitivity, specificity, and accuracy of each imaging criterion as a predictor of bisphosphonate-related fractures were calculated. Similarly, the interobserver agreement and the sensitivity, specificity, and accuracy of diagnosing bisphosphonate-related fractures (i.e., atypical femoral fractures) were determined for the three readers.

RESULTS

Among the candidate predictors of bisphosphonate-related fractures, focal lateral cortical thickening and transverse fracture had the highest odds ratios (76.4 and 10.1, respectively). Medial spike and comminution had odd ratios of 3.8 and 0.63, respectively. Focal lateral cortical thickening and transverse fracture were also the most accurate factors for detecting bisphosphonate-related fractures for all readers. The sensitivity, specificity, and overall accuracy for diagnosing bisphosphonate-related fractures were 94.7%, 100%, and 97.4% for reader 1; 94.7%, 68.4%, and 81.6% for reader 2; and 89.5%, 89.5%, and 89.5% for reader 3, respectively. The interobserver agreement was substantial (κ > 0.61).

CONCLUSION

Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures.

Post-hip fracture use of prescribed calcium plus vitamin D or vitamin D supplements and antiosteoporotic drugs is associated with lower mortality: a nationwide study in Finland

We previously found a positive association between calcium plus vitamin D and antiosteoporotic drugs and survival among hip fracture patients. Our aim was to verify this observation using a nationwide database. A retrospective cohort of home-discharged hip fracture patients aged 50 years or older (n = 23,615) was enrolled from the national database. Primary exposure was medical treatment for osteoporosis, and the outcome was all-cause mortality. Cumulative mortalities were calculated using the Kaplan-Meier estimator. The relationship between mortality and medication purchases was modeled using Cox's proportional hazards regression with time-dependent covariates for medication use. One in 4 women and 1 in 10 men with a hip fracture were treated for osteoporosis in Finland. Unadjusted 1-year mortality was lower among patients who purchased calcium plus vitamin D or vitamin D supplements and antiosteoporotic drugs than among those who did not purchase these medications [hazard ratio (HR) = 0.74, 95% confidence interval (CI) 0.67-0.81]. The difference in unadjusted cumulative mortality remained in favor of the drug users for at least 5 years. Among men, the use of calcium plus vitamin D or vitamin D supplements was associated with lower 1-year mortality even after adjustments for observed confounders (HR = 0.74, 95% CI 0.56-0.97). Among women, the use of antiosteoporotic drugs was associated with lower mortality (HR = 0.79, 95% CI 0.67-0.93). There was a tendency to even better survival in both genders if calcium plus vitamin D or vitamin D supplements and antiosteoporotic drugs were used simultaneously, the HR being 0.72 (95% CI 0.50-1.03) in men and 0.62 (95% CI 0.50-0.76) in women.

Safety of bisphosphonates

Bisphosphonates are one of the most well studied groups of medications and they are bone specific. This tissue specificity is a rare property for a drug introduced into clinical practice as long as 40 years ago. Over the years, the therapeutic boundaries of bisphosphonates were explored and their safety profile has withstood the challenges of the harsh clinical reality and widespread use. Certainly, the esophageal or gastric irritation caused by the oral preparations is an established adverse effect, the risk of which can be reduced by the recommended routine of taking the medication. From the other reported associations with adverse events, osteonecrosis of the jaw (ONJ) and subtrochanteric fractures have attracted most of the attention mainly because their pathophysiology remains unclear. However, overall, only a very small proportion of patients treated with bisphosphonates, especially with the oral formulations, experience adverse events and the overall benefits have consistently outweighed their potential risks. Furthermore, bisphosphonates improve the quality of life in patients with metastatic bone cancer and delay the development of adverse skeletal effects.

The role of bisphosphonates in multiple myeloma: mechanisms, side effects, and the future

Zoledronic acid and pamidronate are two potent anticatabolic nitrogen-containing bisphosphonates (BPs) used extensively in diseases with high bone turnover such as multiple myeloma (MM). In this review we focus on their biology and their current and future use in MM, and highlight some of the most common and emerging side effects. Although the primary target cells for BPs are osteoclasts, new insights suggest other cell types of the bone microenvironment as possible targets, including osteoblasts, endothelial cells, immune cells, and cancer cells. Here, we focus on the current guidelines for the use of BPs in MM and address side effects such as renal toxicity, osteonecrosis of the jaw, and low-energy fractures. Finally, we approach the future of BP use in MM in the context of other bone-targeted agents, evaluating ongoing clinical trials addressing alternate dosing and schedules of BP administration in MM patients.

Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report

This paper reviews the evidence for an association between atypical subtrochanteric fractures and long-term bisphosphonate use. Clinical case reports/reviews and case-control studies report this association, but retrospective phase III trial analyses show no increased risk. Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is yet unproven.

INTRODUCTION

A Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis and the International Osteoporosis Foundation has reviewed the evidence for a causal association between subtrochanteric fractures and long-term treatment with bisphosphonates, with the aim of identifying areas for further research and providing recommendations for physicians.

METHODS

A PubMed search of literature from 1994 to May 2010 was performed using key search terms, and articles pertinent to subtrochanteric fractures following bisphosphonate use were analysed.

RESULTS

Several clinical case reports and case reviews report a possible association between atypical fractures at the subtrochanteric region of the femur in bisphosphonate-treated patients. Common features of these 'atypical' fractures include prodromal pain, occurrence with minimal/no trauma, a thickened diaphyseal cortex and transverse fracture pattern. Some small case-control studies report the same association, but a large register-based study and retrospective analyses of phase III trials of bisphosphonates do not show an increased risk of subtrochanteric fractures with bisphosphonate use. The number of atypical subtrochanteric fractures in association with bisphosphonates is an estimated one per 1,000 per year. It is recommended that physicians remain vigilant in assessing their patients treated with bisphosphonates for the treatment or prevention of osteoporosis and advise patients of the potential risks.

CONCLUSIONS

Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is unproven and requires further research. Were the case to be proven, the risk-benefit ratio still remains favourable for use of bisphosphonates to prevent fractures.

Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research

Reports linking long-term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross-linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long-term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Given the relative rarity of atypical femoral fractures, the task force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance, and additional epidemiologic and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopedic and medical management.

5-Androstene-3β,7β,17β-triol (β-AET) slows thermal injury induced osteopenia in mice: relation to aging and osteoporosis

5-androstene-3β,7β,17β-triol (β-AET), an active metabolite of dehydroepiandrosterone (DHEA), reversed glucocorticoid (GC)-induced suppression of IL-6, IL-8 and osteoprotegerin production by human osteoblast-like MG-63 cells and promoted osteoblast differentiation of human mesenchymal stem cells (MSCs). In a murine thermal injury model that includes glucocorticoid-induced osteopenia, β-AET significantly (p<0.05) preserved bone mineral content, restored whole body bone mineral content and endochondral growth, suggesting reversal of GC-mediated decreases in chondrocyte proliferation, maturation and osteogenesis in the growth plate. In men and women, levels of β-AET decline with age, consistent with a role for β-AET relevant to diseases associated with aging. β-AET, related compounds or synthetic derivatives may be part of effective therapeutic strategies to accelerate tissue regeneration and prevent or treat diseases associated with aging such as osteoporosis.