Presentation
History withheld.
Patient Data



X-rays of the knees and leg demonstrate prominent horizontal sclerotic lines affecting the metaphyses, relatively evenly spaced. The legs demonstrate gracile bones and bowing of the tibia.
The distance between the lines at the distal end of the leg is less than that at the proximal end. This is a reflection of the greater growth occurring around the knee; as the doses of pamidronate disodium are given regularly, more growth has occurred between doses at the knee than at the ankle.
Case Discussion
Findings are in keeping with the so-called Zebra sign of pamidronate disodium therapy for osteogenesis imperfecta (the diagnosis was established clinically).