[Characteristics of the joint involvement in fibrodysplasia ossificans progressiva and follow up].

To summarize the clinical data of 15 patients with fibrodysplasia ossificans progressiva (FOP), follow up and analyze the characteristics of the joint involvement in FOP. From May 2005 to December 2016, fifteen FOP cases had been diagnosed in the Children's Hospital Capital Institute of Pediatrics. All medical records and follow-up data were collected and a retrospective analysis was made on the joint involvement in FOP. Pearson correlation analysis was used for data, <0.05 for the difference was statistically significant. There were 8 males and 7 females in 15 cases. The age of onset was 2(1-6)years. The age at diagnosis was 6 (4-9) years. All cases had hallux valgus deformity and bone mass formation. Twelve cases had joints involvement on enrollment into this study: 8 cervical vertebra, 7 shoulder joint, 5 hip joint, 4 elbow joint, 3 wrist joint, 2 temporomandibular joint, 2 lumbar vertebra. The age of diagnosis and duration of disease were positively correlated with the number of the involved joints (=0.523, 0.628; =0.045, 0.012); mild changes were found in joint imaging. Thirteen cases received telephone follow-up, the average duration of follow-up was 6(3-7)years, no change in 11 cases, disease progress in 2 cases. Joint involvement is a common complication of FOP, especially the cervical vertebra.Multiple joints involvement, dominant functional impairment, and mild imaging changes are the characteristics of joint lesions caused by FOP.The number of involved joints gradually increases with increase of age of the patients and the prolonged course of the disease.