Spinal Involvement in Chronic Recurrent Multifocal Osteomyelitis (CRMO) in Childhood and Effect of Pamidronate

There are only a few studies that address the frequency and type of spinal involvement in patients with chronic recurrent multifocal osteomyelitis (CRMO) as well as the outcome of these patients treated with pamidronate (PAM). We performed a retrospective study on patients with CRMO and analyzed clinical and pain assessments as well as regional and whole body MRI findings and compared with posttreatment findings. Of 102 children and adolescents with CRMO, 27 (26%) had involvement of the spine. Vertebral deformities were seen in 14 of these 27 patients, scoliosis or kyphosis in 6. After routine whole body MRI, 19 complained of back pain, whereas eight were asymptomatic with spinal lesions detected incidentally. A total of 72 spinal lesions were detected, thoracic vertebrae being the most commonly affected. Seven patients were treated with PAM; all of whom had vertebral deformities and ongoing back pain. Pain resolution was achieved within 3 months of PAM treatment in every case. One patient subsequently developed a pain amplification syndrome. Repeat MRI performed at a mean interval of 13 months revealed partial or complete resolution of vertebral hyperintensities in every patient. Improvement of vertebral height was seen in a total of three vertebrae in two patients. Severe side effects were not observed. In conclusion, we demonstrated that spinal involvement and associated vertebral deformities with or without kyphoscoliosis are not rare in CRMO, and PAM appears to be an effective and safe treatment for this condition. Although controlled studies are urgently needed, the use of PAM for refractory CRMO with extended spinal involvement (vertebral deformities, kyphosis, and scoliosis) should be considered, especially after failing of conventional therapy.