AB1060 BONE MARROW FOOT OEDEMA IN CHILDREN: THE ROLE OF VITAMIN D

Abstract

Background Bone marrow oedema (BMO) in children is a rare clinical condition characterized by joint and bone extremity pain, out of proportion to the clinical findings, exacerbated by weight bearing, in the absence of a known etiologic cause. It is associated with typical increased signal intensity on T2-weighted MRI. Management is still under debate. Treatment has mostly been reported in adult case series encompassing analgesic drugs, a variety of pharmacological treatments (corticosteroids, bisphosphonates, vasodilators), physiotherapy, reduction of weight-bearing, or core decompression. No treatment guidelines for children are to date available. Objectives Recently it has become evident that BMO is associated by an increase in bone turnover, in which vitamin D plays a pivotal role. In literature association between hypovitaminosis D and BMO of the foot and ankle in adult patients is reported. No data are reported in cohorts of children. The purpose of this study is to investigate the incidence of hypovitaminosis D in a paediatric population with primary bone BMO of the feet and the role of a vitamin D supplementation therapy. Methods A retrospective study involving 12 paediatric patients (range age 8-14 years) referred to our Rheumatologic Paediatric Clinic of Verona University in the period 2015-2018 with persistent foot pain and MRI compatible with BMO of the foot has been performed. They had all been misdiagnosed in other institutions as affected by algodystrophy or complex regional pain syndrome. Data collection included sex, age, medical and surgical history, recent or remote trauma history, symptoms at presentation, clinical examination, laboratory bone turnover markers, vitamin D levels, MRI, treatment and outcome. Results 2/12 patients are male and 10/12 female (male to female ratio: 1:5). 2/12 had a previous diagnosis of juvenile idiopathic arthritis ANA + with the disease in remission at the moment of evaluation. 10/12 were previously healthy. In all cases history of minor ankle strain or recurrent microtraumas of feet prior to symptom onset had been reported. Joint hypermobility was observed in 75% of cases. One child had been previously treated with bisphosphonates and 5 with limb immobilization, without any improvement. Physical examination revealed weight bearing pain of foot or ankle in all patients. No other sensory, vasomotor, trophic ore neurological signs and symptoms were detected. Vitamin D deficiency was found in all cases (range 10 to 22 ng/ml). All patients were thus treated with adequate vitamin D daily intake. Pain relief was achieved with paracetamol, low dose ibuprofen, or a short course of oral prednisone. Rest from intense physical activity and physical therapy, avoiding detrimental feet and ankle immobilization were recommended. All children (100%) fully recovered in 3-month lag period. Conclusion BMO in children is a cause of disability and it is often misdiagnosed and incorrectly treated. Environmental factors, such as underestimated articular or bone microtraumatisms, as well as joint hyper mobility, typical of paediatric age, in a bone turnover milieu of vitamin D deficiency could be the cause of the clinical conditions. Adequate vitamin D supplementation, associated with physical and analgesic therapy, are crucial in the management of BMO. We highlight the importance of supplementing vitamin D as recommended in the current guidelines, in order to avoid its deficiency and prevent invalidating clinical complaints.