The cumulative incidence of and risk factors for latent beaking in patients with autoimmune diseases taking long-term glucocorticoids and bisphosphonates

Incidence and clinical course of femoral localized periosteal thickening and atypical femoral fracture over a 10-year period in patients with autoimmune inflammatory rheumatic disease

Atypical femoral fracture (AFF) is generally a rare complication of long-term use of bisphosphonate (BP); glucocorticoid (GC) use and Asian race are also risk factors. Femoral localized periosteal thickening (LPT, also termed "beaking") of the lateral cortex often precedes AFF. This cohort study investigated the incidence of LPT and AFF and their clinical courses over 10 yr in patients with autoimmune inflammatory rheumatic diseases (AIRDs) treated with BP and GC. The study population consisted of 121 patients with AIRDs taking BP and GC. LPT was screened by X-ray, and the LPT shape was evaluated. Prednisolone (PSL) dose was 10 (8-12) mg/d at enrollment and 9 (6-10) mg/d at the last observation. LPT was evident in 10 patients at enrollment and increased linearly to 31 patients (26%) at the last observation. AFF occurred in 9 femurs of 5 patients with LPT. All patients with AFF had bilateral LPT, and the prevalence of pointed type and LPT height were higher in the AFF-positive group than in the AFF-negative group. AFF occurred before BP discontinuation in 2 patients, 1 yr after BP discontinuation in 1, after BP discontinuation followed by 7 yr of alfacalcidol use in 1, and after switching from alfacalcidol to denosumab in 1. The prevalence rates of AFF and LPT associated with long-term BP use with concomitant use of GC (mostly PSL ≥ 6 mg/d) in Japanese patients with AIRD increased over time. The selection of long-term osteoporosis treatment for LPT-positive patients is difficult in some cases.

Bilateral Subtrochanteric Complete Atypical Femoral Fracture in a Patient With Rheumatoid Arthritis: A Case Report

Antiresorptive drugs such as bisphosphonates (BPs) or denosumab, used for the treatment of osteoporosis over the past decades, have improved bone mineral density and reduced the incidence of fractures. However, there are increasing evidence that atypical femoral fractures (AFFs) are related to long-term use of these medications.

We had experienced bilateral simultaneous subtrochanteric complete AFFs in having rheumatoid arthritis (RA) for 15 years. She just had been taking risedronate for three months prior to this event. Fractures were treated with long cephalomedullary nails. We could get a bone union for the right side at 15 months after index surgery. However, two more surgeries were needed to get bone union for the left side. This study aimed to share our treatment strategy and review of the literature on the correlation between RA and AFFs.

The Risks of Femoral Localized Periosteal Thickening in Patients with Autoimmune Inflammatory Rheumatic Diseases

PURPOSE

The incidence of femoral localized periosteal thickening (LPT), which can precede atypical femoral fracture (AFF), is not low (1-10%) in Japanese patients with autoimmune inflammatory rheumatic diseases (AIRDs). We explored the associations between underlying AIRDs and the prevalence of LPT.

METHODS

We conducted post-hoc analyses of two cohorts that included a total of 280 Japanese women, 105 of whom had AIRDs and had been taking bisphosphonate (BP) and prednisolone (PSL), and 175 of whom had rheumatoid arthritis (RA).

RESULTS

LPT was detected in a total of 18 patients (6.4%) and three (1.1%) developed AFFs. RA was negatively correlated with LPT. A disease other than RA requiring glucocorticoid treatment, BP use ≥ 5 years, PSL use ≥ 7 years, and a PSL dose ≥ 5.5 mg/day were positively correlated with LPT. After adjusting for age, diabetes mellitus, and BP duration or daily PSL dose, RA was no longer associated with LPT.

CONCLUSION

LPT in Japanese patients with AIRDs was associated with BP and glucocorticoid treatment rather than underlying AIRDs. When a PSL dose ≥ 5.5 mg/day is required long-term (typically combined with long-term BP treatment [≥ 5 years]), clinicians need to pay particular attention in case LPT and AFF, as well as glucocorticoid-induced osteoporosis.

Lower trabecular bone score is associated with an increased incidence of localized femoral periosteal thickening

INTRODUCTION

Femoral localized periosteal thickening (LPT, also termed "beaking") of the lateral cortex often precedes an atypical femoral fracture (AFF). Bisphosphonate (BP) use, glucocorticoid use, and Asian race are major risk factors for developing such fractures. The aim of this study was to determine whether the trabecular bone score (TBS) reflecting the lumbar trabecular microarchitecture was related to LPT in glucocorticoid-treated Japanese patients with autoimmune diseases.

MATERIALS AND METHODS

We retrospectively investigated 111 women with autoimmune diseases treated with prednisolone (PSL) who had undergone both femoral X-ray and dual-energy X-ray absorptiometry of the L1 - L4 lumbar vertebrae and for whom TBS could be evaluated for two or more of these.

RESULTS

Femoral LPT was evident in the X-rays of 18 of 111 patients (16.2%). Higher body mass index (BMI), longer duration of PSL use and longer duration of BP use were significant in patients with LPT compared to those without. The TBS was significantly lower in patients with LPT than in those without (1.314 ± 0.092 vs. 1.365 ± 0.100, p = 0.044); however, the lumbar bone mineral density did not differ significantly (0.892 ± 0.141 vs. 0.897 ± 0.154 g/cm², p = 0.897). TBS was significantly associated with LPT (odds ratio, 0.004; 95% CI, 0 - 0.96; p = 0.048), but not in the multivariate analysis including BMI, duration of PSL use and duration of BP use.

CONCLUSIONS

The TBS was lower in glucocorticoid-treated Japanese women with autoimmune diseases with LPT than in those without LPT, and deteriorated trabecular microarchitecture influenced by longer use of BP and glucocorticoid might be associated with the development of LPT.

Differences in subtrochanteric and diaphyseal atypical femoral fractures in a super-aging prefectural area: YamaCAFe Study

INTRODUCTION

Atypical femoral fractures (AFFs) have been correlated with long-term use of bisphosphonates (BPs), glucocorticoids (GCs), and femoral geometry. We investigated the incidence and characteristics of subtrochanteric (ST) and diaphyseal (DP) AFFs in all institutes in a super-aging prefectural area.

MATERIALS AND METHODS

We performed a blinded analysis of radiographic data in 87 patients with 98 AFFs in all institutes in Yamagata prefectural area from 2009 to 2014. Among the 98 AFFs, 57 AFFs comprising 11 ST fractures in 9 patients and 46 DP fractures in 41 patients with adequate medical records and X-rays were surveyed for time to bone healing and geometry.

RESULTS

Of the 87 patients, 67 received BPs/denosumab (77%) and 10 received GCs (11%). Surgery was performed in 94 AFFs. Among 4 AFFs with conservative therapy, 3 required additional surgery. In univariate regression analyses for ST group versus DP group, male-to-female ratio was 2/7 versus 1/40, mean age at fracture was 58.2 (37-75) versus 78 (60-89) years, rheumatic diseases affected 55.5% (5/9) versus 4.9% (2/41), femoral lateral bowing angle was 1.7 (0-6) versus 11.8 (0.8-24)°, GC usage was 67% (6/9) versus 4.9% (2/41), and bone healing time was 12.1 (6-20) versus 8.1 (3-38) months (p < 0.05). In multivariate analyses, higher male-to-female ratio, younger age, greater proportion affected by rheumatic diseases, and higher GC usage remained significant (p < 0.05).

CONCLUSIONS

The incidence of AFFs in our prefectural area was 1.43 cases/100,000 persons/year. This study suggests that the onset of ST AFFs have greater correlation with the worse bone quality, vice versa, the onset of DP AFFs correlated with the bone geometry. The developmental mechanisms of AFFs may differ significantly between ST and DP fractures.

Evaluation and management of atypical femoral fractures: an update of current knowledge

Atypical femoral fractures are often attributed to the use of anti-resorptive medications such as bisphosphonates (BP). Whilst they have proven effects on fragility fracture prevention, clinical and laboratory evidence is evolving linking BP-related suppression of bone remodelling to the development of atypical stress-related sub-trochanteric fractures (Shane et al. in JBMR 29:1-23, 2014; Odvina et al. in JCEM 90:1294-301, 2005; Durchschlag et al. in JBMR 21(10):1581-1590, 2006; Donnelly et al. in JBMR 27:672-678, 2012; Mashiba et al. in Bone 28(5):524-531, 2001; Dell et al. in JBMR 27(12):2544-2550, 2012; Black et al. in Lancet 348:1535-1541, 1996; Black et al. in NEJM 356:1809-1822, 2007; Black et al. in JAMA 296:2927-2938, 2006; Schwartz et al. in JBMR 25:976-82, 2010). Injuries may present asymptomatically or with prodromal thigh pain and most can be successfully managed with cephalomedullary nailing and discontinuation of BP therapy. Such injuries exhibit a prolonged time to fracture union with high rates of non-union and metal-work failure when compared to typical subtrochanteric osteoporotic femoral fractures. Despite emerging literature on AFFs, their management continues to pose a challenge to the orthopaedic and extended multi-disciplinary team. The purpose of this review includes evaluation of the current evidence supporting the management of AFFs, clinical and radiological features associated with their presentation and a review of reported surgical strategies to treat and prevent these devastating injures.

Cumulative incidence of femoral localized periosteal thickening (beaking) preceding atypical femoral fractures in patients with rheumatoid arthritis

The incidence of localized periosteal thickening (LPT, also termed beaking) of the lateral cortex that often precedes an atypical femoral fracture (AFF) was not high in patients with rheumatoid arthritis (RA) but incomplete AFFs developed in two patients. Higher-dose prednisolone was a significant risk factor for LPT in patients with RA.

INTRODUCTION

Atypical femoral fractures (AFFs) are stress fractures; bisphosphonate (BP) use is a major risk factor for the development of such fractures. Localized periosteal thickening (LPT, also termed beaking) of the lateral cortex often precedes a complete or incomplete AFF. We evaluated the incidence of latent LPT in patients with rheumatoid arthritis (RA), to evaluate LPT progression, and to define LPT risk factors.

METHODS

A total of 254 patients with RA were included; all underwent annual X-ray evaluation, dual-energy X-ray absorptiometry, and analyses of serum and bone metabolic markers for 2-3 years. LPT of the lateral cortex was sought in femoral X-rays.

RESULTS

The incidence of LPT was 2.4% (6/254). Among patients on both BP and prednisolone (PSL) at enrollment, the incidence was 2.3% (3/131). Two femurs of two patients with LPT developed incomplete AFFs; LPT was extensive and associated with endosteal thickening. One patient had been on BP and PSL and microscopic polyangiitis was comorbidity. The other was on a selective estrogen receptor modulator and PSL. A daily PSL dose >5 mg (OR 11.4; 95%CI 2.15-60.2; p = 0.004) and higher-dose methotrexate (OR 1.22; 95%CI 1.01-1.49; p = 0.043) were significant risk factors for LPT.

CONCLUSIONS

The incidence of latent LPT was not high (2.4%) but incomplete AFFs developed in two RA patients. Higher-dose PSL because of a comorbid disease requiring glucocorticoid treatment other than RA or refractory RA were risk factors for LPT; X-ray screening for latent LPT would usefully prevent complete AFFs.

Clinical Features and Outcomes of Bilateral Atypical Femoral Fractures

Bilateral atypical femoral fractures (AFFs) are relatively rare. In this report, we retrospectively researched clinical features and outcomes of bilateral AFFs treated at our institution. We previously treated 4 patients (8 limbs) with intramedullary nailing for complete AFFs (6 limbs) and incomplete AFFs (2 limbs). The mean age at the first operation was 53.3 years, and all patients were female. Of the 4 patients, two had breast cancer, and another two had systemic lupus erythematosus. Three of them received bisphosphonates, and 2 received denosumab, proton pump inhibitor, or glucocorticoid therapy. Only 2 of 6 cases of incomplete AFFs had prodromal pain before progressing to complete fracture. The mean interval from the first surgery to contralateral fracture or prophylactic surgery was 16 months. Radiographically, complete bone union was achieved in 6 limbs. However, a small gap at the lateral cortex of fracture site remained in 2 limbs. Finally, all of the patients were pain-free and able to walk without a cane. It is absolutely necessary to confirm contralateral femoral conditions; however, prediction of progression to complete fracture based solely on prodromal pain was difficult. Therefore, we should advise patients about the danger of progression to complete AFFs even if they are asymptomatic, and a prophylactic surgery should be performed after obtaining informed consent.

Detection of Atypical Femur Fractures

The 2019 International Society for Clinical Densitometry (ISCD) Position Development Conference Task Force for monitoring with dual-energy X-ray absorptiometry (DXA) identified detection of atypical femur fractures (AFFs) as an important topic and established this working group to answer key questions in this area. The authors conducted a systematic review of the literature and deliberated on proposed ISCD positions, which were then reviewed by an external expert panel and vetted at the 2019 ISCD Position Development Conference in Kuala Lumpur on March 23, 2019. This paper summarizes the final ISCD positions and the rationale for supporting these positions. Default-length femur imaging or extended-length femur imaging as well as full-length femur imaging (FFI), both single-energy and dual-energy scans, by DXA can detect abnormalities in the spectrum of AFF. It is important to visually inspect all DXA scans of the hip and femur, and report on findings of focal periosteal and endosteal thickening at the lateral cortex (grade: Good, A, W). FFI is the preferred DXA scan mode for detecting abnormalities in the spectrum of AFF. The FFI report should state the absence or presence of abnormalities in the spectrum of AFF. If focal thickening is present on the lateral cortex, the report should state whether a lucent line is seen (grade: Fair, C, W). The ISCD recommends considering the use of bilateral FFI in patients who are currently or have been in the past year on potent antiresorptive therapy (ie, oral or intravenous bisphosphonate or subcutaneous denosumab therapy) for a cumulative period of 3 or more years, especially those on long-term glucocorticoid therapy (grade: Fair, B, W). More research is needed to determine the role of repeat testing and the optimal time interval for follow-up DXA scans, whether an automated measuring tool would perform better than visual inspection, whether FFI would change patient management and outcomes, and the cost-effectiveness of FFI.

High bisphosphonate treatment rates and the prevalence of atypical femoral fractures in patients with systematic lupus erythematosus: a single-center retrospective study performed in Japan

Treatment of systemic lupus erythematosus (SLE) often continues with moderate-to-low doses of glucocorticoids for the long term. Bisphosphonates aid in the prevention and management of glucocorticoid-induced osteoporosis (GIOP). However, long-term use of bisphosphonates increases the relative risk of atypical femoral fracture (AFF) and the incidence is typically 16 or 113 per 100,000 person-years in patients treated with bisphosphonates for 5 or 10 years, respectively. Here, we explored bisphosphonate prescription rate and prevalence of AFF in patients with SLE. In total, 270 patients with SLE were enrolled. The Japanese Society for Bone and Mineral Research Guideline 2014 for GIOP management and treatment was used. We also explored AFF history through medical records. Most (n = 251) patients were recommended to treat by the GIOP guideline (scores ≥ 3); bisphosphonates, denosumab, teriparatide, or active vitamin D was prescribed for 85.7%. Bisphosphonates were currently used by 66.1% of the patients, and 65% had used them for ≥ 5 years. Of all patients, 76.7% had a history of bisphosphonate use, 5 of 270 (1.9%) had histories of AFF. Four of five patients with AFF had taken bisphosphonates for ≥ 3.5 years, in addition to moderate doses (≥ 10 mg/day) of glucocorticoids. For the SLE patients with a history of bisphosphonate use, the incidence of AFF was calculated to be 278 per 100,000 person-years. Our single-center study found that bisphosphonates were commonly used long term by Japanese patients with SLE. As AFF is not rare, AFF should be cared in patients with SLE.

Current Understanding of Epidemiology, Pathophysiology, and Management of Atypical Femur Fractures

PURPOSE OF REVIEW

To summarize reports published since the 2013 American Society of Bone and Mineral Research Task Force Report on atypical femoral fractures (AFF).

RECENT FINDINGS

The absolute incidence of AFFs remains low. AFFs are primarily associated with prolonged bisphosphonate (BP) exposure, but have also been reported in unexposed patients and those receiving denosumab for osteoporosis and metastatic bone disease. Asians may be more susceptible to AFFs. Lateral femoral bowing and varus hip geometry, which increase loading forces on the lateral femoral cortex, may increase AFF risk. Altered bone material properties associated with BP therapy may predispose to AFFs by permitting initiation and increasing propagation of micro-cracks. Relevant genetic mutations have been reported in patients with AFFs. Single X-ray absorptiometry femur scans permit early detection of incomplete and/or asymptomatic AFFs. Orthopedists recommend intramedullary rods for complete AFFs and for incomplete, radiologically advanced AFFs associated with pain and/or marrow edema on MRI. Teriparatide may advance AFF healing but few data support its efficacy. Greater understanding of biological and genetic predisposition to AFF may allow characterization of individual risk prior to initiating osteoporosis therapy and help allay fear in those at low risk for this complication, which remains rare in comparison to the osteoporotic fractures prevented by antiresorptive therapy.

High and pointed type of femoral localized reaction frequently extends to complete and incomplete atypical femoral fracture in patients with autoimmune diseases on long-term glucocorticoids and bisphosphonates

Once a localized reaction (beaking) was detected, discontinuation of bisphosphonates (BPs) and switching to vitamin D supplementation or teriparatide therapy effectively improved its shape. When the localized reaction was high, of the pointed type, and/or accompanied by prodromal pain, the risks of complete and incomplete atypical femoral fracture increased and consideration of prophylactic fixation for such patients was required.

INTRODUCTION

Femoral localized reaction (localized periosteal thickening of the lateral cortex, beaking) is reported to precede atypical femoral fractures (AFFs) and to develop in 8-10% of patients with autoimmune diseases taking BPs and glucocorticoids. The aims of the present study were to retrospectively investigate the shapes of localized reaction to consider how to manage the condition.

METHODS

Twenty femora of 12 patients with autoimmune diseases who were on BPs and glucocorticoids exhibited femoral localized reaction. The heights of localized reaction were measured and the shapes classified as pointed, arched, and other. Localized reaction changes were divided into three categories: deterioration, no change, and improvement. A severe form of localized reaction was defined; this was associated with prodromal pain, de novo complete AFF, or incomplete AFF with a fracture line at the localized reaction.

RESULTS

The mean height of localized reaction was 2.3 ± 0.8 mm (range, 1.0-3.7 mm) and the pointed type was 35%. Localized reaction was significantly higher (3.3 ± 0.8 vs. 2.1 ± 0.7 mm; p = 0.003) and the pointed type more common (78 vs. 27%; p = 0.035) in those with the severe form of localized reaction. Seven patients with localized reactions discontinued BPs just after localized reaction was detected, but five continued on BPs for 2 years. Localized reaction deterioration was more common in patients who continued than discontinued BPs (100 vs. 29%; p = 0.027). After 2 years, all patients had discontinued BPs and localized reaction did not deteriorate further in any patient.

CONCLUSIONS

Once a localized reaction was detected, discontinuation of BPs and switching to vitamin D supplementation or teriparatide therapy effectively improved it. When the localized reaction was high, of the pointed type, and/or accompanied by prodromal pain, the risks of complete and incomplete AFF increased and consideration of prophylactic fixation for such patients was required.

Molecular Abnormalities Underlying Bone Fragility in Chronic Kidney Disease

Prevention of bone fractures is one goal of therapy for patients with chronic kidney disease-mineral and bone disorder (CKD-MBD), as indicated by the Kidney Disease: Improving Global Outcomes guidelines. CKD patients, including those on hemodialysis, are at higher risk for fractures and fracture-related death compared to people with normal kidney function. However, few clinicians focus on this issue as it is very difficult to estimate bone fragility. Additionally, uremia-related bone fragility has a more complicated pathological process compared to osteoporosis. There are many uremia-associated factors that contribute to bone fragility, including severe secondary hyperparathyroidism, skeletal resistance to parathyroid hormone, and bone mineralization disorders. Uremia also aggravates bone volume loss, disarranges microarchitecture, and increases the deterioration of material properties of bone through abnormal bone cells or excess oxidative stress. In this review, we outline the prevalence of fractures, the interaction of CKD-MBD with osteoporosis in CKD patients, and discuss possible factors that exacerbate the mechanical properties of bone.

Chronic kidney disease and fragility fracture

Osteoporosis is defined simply as "a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture. Thus, any bone lesion that causes fragility fracture is osteoporosis, which has quite heterogeneous backgrounds. Chronic kidney disease-related bone and mineral disease (CKD-MBD) is defined as "a systemic disorder of mineral and bone metabolism due to CKD, which is manifested by abnormalities in bone and mineral metabolism and/or extra-skeletal calcification". Although CKD-MBD is one of the possible causes of osteoporosis, we do not have evidences that CKD-MBD is the only or crucial determinant of bone mechanical strength in CKD patients. The risk of hip fracture is considerably high in CKD patients. Drugs that intervene in systemic mineral metabolism, indeed, lead to the improvement on bone histology in CKD patients. However, it remains unclear whether the intervention in systemic mineral metabolism also improves bone strength, today. Thus, the use of drugs that directly act on bone and the introduction of fracture liaison concept are promising strategies for fragility fracture prevention among CKD patients, as well as treatment for CKD-MBD.