Endocrine Abstracts

Introduction: Regional Migratory Osteoporosis (RMO) is a rare condition, characterised by a self-limiting migratory arthralgia, which generally tends to involve the lower limbs. The arthralgia is usually, not associated with any history of trauma. Radiologically, Magnetic Resonance Imaging (MRI) is the investigation of choice. Bone Marrow Oedema (BMO) with subchondral sparing are the usual findings in patients with RMO. This condition is usually under diagnosed due to the complexity and lack of classical features.

Case details: We report the case of a 59-year-old gentleman, who presented to his General Practitioner (GP) with traumatic Right second toe pain, accompanied by significant deterioration in Quality-of-life (QOL). On X-Ray, there was no evidence of acute fractures. The symptoms at the time, were managed with analgesia and strapping.Subsequently, a year later, he incurred symptoms of pain and stiffness in the Right third and fourth toes, which was not preceded by a history of trauma. On this occasion, there was involvement of the Right hip as well. In total, at this point his QOL was severely impacted over the course of the last 18 months.He was then referred to the Tertiary sports and exercise specialist, for expert input. An MRI scan detected bone and soft tissue oedema centred on the second and third metatarsal heads involving the surrounding muscles, subcutaneous tissues and proximal and perhaps the middle phalanges. Mild plantar bone marrow oedema seen of the fourth metatarsal head.The appearances were highly suggestive of RMO, which instigated a referral to Metabolic bone services.A battery of investigations showed normal renal functions, Adjusted Calcium levels, Thyroid status and Vitamin D levels. Extended screening for Coeliac disease, Testosterone deficiency, Multiple Myeloma and Hyperparathyroidism were normal.

Management: A discussion in the Metabolic Bone Multi-Disciplinary setting advised repeat MRI and treatment with Bisphosphonates. The repeat MRI confirmed appearances in keeping with Transient BMO syndrome.Treatment with Intravenous Zoledronate alleviated his symptoms significantly and shortened recovery time, with Improvement in QOL.

Discussion: Till this date, the aetiology of RMO remains unclear. The key to diagnosis lies in a thorough clinical history supplemented by radiological findings. The radiology of RMO resembles Transient Osteoporosis of the Hip (TOH) and thus, the history of migratory arthralgia is key in distinguishing between both entities.Treatment options generally involve repletion of Vitamin D and Calcium levels, where appropriate. Bisphosphonates have been shown to improve symptoms and shorten recovery time.