Operative Management of Spinal Deformity Secondary to Hajdu-Cheney Syndrome.

Hajdu-Cheney syndrome (HCS) is an exceedingly rare disease with fewer than 100 cases described in the medical literature. It is most strongly associated with a defect in the transmembrane protein NOTCH2. Though the exact mechanism in humans is not yet known, the defect results in various skeletal abnormalities including severe osteoporosis placing these patients at high risk for progressive spinal deformity. Due to various common syndromic features including ligamentous laxity, increased osteoclast activity, skeletal malformations, patency of cranial sutures, and the aforementioned severe osteoporosis, these patients require special consideration from treating surgeons. There are currently only nine reported cases of spinal surgery in HCS patients. Herein, we describe the cases of two patients with HCS requiring surgery for progressive spinal deformity. Six months following surgery, both patients reported excellent outcomes with significant improvement in symptoms.