Surgical challenges in the management of cervical kyphotic deformity in patients with severe osteoporosis: an illustrative case of a patient with Hajdu-Cheney syndrome.

<bold>Purpose: </bold>No standard strategy exists for the management of cervical kyphotic deformity in patients with severe osteoporosis. In fact, in such subpopulation, standard algorithms commonly used in patients with normal bone mineral density may not be applicable. In this Grand Rounds, the authors present a challenging case of a patient with Hajdu-Cheney syndrome, a rare disorder of bone metabolism induced by a Notch-2 mutation, who presented with cervical kyphotic deformity and severe osteoporosis.<bold>Methods: </bold>A 65-year-old female patient with a previous diagnosis of Hajdu-Cheney syndrome presented with cervical myelopathy and cervical kyphotic deformity. The initial MRi demonstrated multilevel cervical canal stenosis. The CT-scan also revealed marked spondylolisthesis of C6 over C7 as well as numerous laminar and pedicle fractures, resulting in a cervical kyphosis of approximately 50 degrees.<bold>Results: </bold>The patient was submitted to 360-degree decompression and fusion of the cervical spine consisting of a staged C6 anterior corpectomy and multilevel microdiscectomies with wide opening of the posterior longitudinal ligament in order to provide a satisfactory release of anterior spinal structures, followed by 24 h of cervical halo-traction, a second anterior approach for bone graft implantation in the site of the corpectomy as well as insertion of allografts and completion of the ACDF C2-T1 and plating, and, finally, a posterior C2-T3 pedicle screw instrumentation using intra-operative CT-scan (O-arm) navigation guidance.<bold>Conclusions: </bold>This case illustrates some intra-operative nuances as well as specific surgical recommendations for cervical deformity surgery in patients with severe osteoporosis, such as avoidance of Caspar pins for interbody distraction, use of intra-operative fluoroscopy for achievement of bicortical purchase of anterior cervical screws and placement of pedicle screws during posterior instrumentation. Moreover, such illustrative case demonstrates that, in the subpopulation of patients with severe osteoporosis, it may be possible to successfully apply cervical distraction after an isolated anterior approach with a satisfactory improvement in the cervical alignment, possibly avoiding more laborious 540-degree approaches such as the previously described back-front-back or front-back-front surgical algorithms. [ABSTRACT FROM AUTHOR]