Premature partial closure and other deformities of the growth plate: MR imaging and three-dimensional modeling

PURPOSE: To examine growth plates of the distal femur and tibia with magnet ic resonance (MR) imaging to detect bone bridges and other deformities in c hildren. MATERIALS AND METHODS: Thirteen children (nine boys and four girls, aged 5- 13 years; mean age, 9.8 years) were referred because of suspected or known bone bridging of the growth plate. Among the 13 patients, 10 had Salter-Har ris fractures of the knee or ankle, two had Blount disease, and one had neo natal sepsis. Fat-saturated spoiled gradient-recalled images enabled recons truction of a three-dimensional model of the growth plate. Patients underwe nt one to four MR examinations. RESULTS: Nine patients had bone bridging of less than 1% to 39% of the area of the growth plate. On MR images obtained in the growth plate of five pat ients, a stripe of low signal intensity indicated fracture. On MR images ob tained in three patients, intrusions of growth plate cartilage into the met aphysis were seen to increase in depth overtime. MR images obtained in four patients showed no bridges. In the two patients who underwent surgery, exc ellent correspondence was found between MR findings and surgical observatio ns. CONCLUSION: Marked undulation or splitting of the growth plate may occur wi th fixation of some cartilage in the metaphysis or epiphysis while growth c ontinues. The configuration of the growth plate and bone bridges can be acc urately mapped with MR imaging. Treatment planning is facilitated.