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

Treatment strategy for atypical ulnar fracture due to severely suppressed bone turnover caused by long-term bisphosphonate therapy: a case report and literature review

BACKGROUND

Atypical fractures may occur due to the combined effect of severely suppressed bone turnover (SSBT) caused by long-term bisphosphonate treatment and chronic repetitive bone microdamage. Atypical fracture of the ulna due to SSBT is a rare entity; there is no standardized treatment strategy for this condition. We successfully treated a patient with atypical fracture of the ulna. Herein, we present this patient, review the relevant literature, and discuss the treatment strategy.

CASE PRESENTATION

An 84-year-old woman presented with atypical fracture of the left ulnar shaft due to SSBT. She had a history of bisphosphonate therapy (ibandronate and alendronate) since more than 10 years; her bone turnover was severely suppressed. We performed open reduction and internal fixation (ORIF) using dual plate with some additional treatments. These included drilling and decortication, use of autogenous bone graft, low-intensity pulsed ultrasound (LIPUS) treatment, and administration of teriparatide. Finally, bone union was observed at 11 months after surgery.

CONCLUSIONS

Based on the literature review and our experience with this case, ORIF alone may not be adequate to achieve bone union; drilling, decortication, and use of cancellus bone graft is important to achieve favorable outcomes. Administration of teriparatide and LIPUS may facilitate early bone union, although further studies are required to provide more definitive evidence. Furthermore, ORIF using dual plate may help avoid implant failure owing to the long time required for bone union.

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.

Atypical Femur Fractures in Patients Treated with Bisphosphonates: Identification, Management, and Prevention

Osteoporosis is a common condition with significant health care costs. First-line therapy is with bisphosphonates, which have proven anti-fracture efficacy. Around 10 years after the introduction of bisphosphonates reports began to be published of atypical femoral fractures (AFFs) that may be associated with this therapy. These fractures are associated with significant morbidity although lower mortality than the more common osteoporotic neck-of-femur fractures. A case definition has been described to allow identification of this class of fracture. Further work has established a high relative risk of AFFs in patients treated with bisphosphonates, but a low absolute risk in comparison to that of osteoporotic fractures. Proposed pathological mechanisms include low bone turnover states leading to stress/insufficiency fractures. Clinicians should be aware of the risk of AFFs and in particular the high rate of prodromal thigh/groin pain that warrants investigation in a patient receiving a bisphosphonate. If an incomplete fracture is diagnosed then bisphosphonate therapy needs to be stopped and prophylactic surgery may be considered. Due to these rare side effects patients on bisphosphonates require regular review, and this is particularly advised after 5 years of oral or 3 years of intravenous therapy.