SURGICAL CORRECTION COMPLICATED BY CARDIAC ARRESTOF “CHIN-ON-CHEST” DEFORMITY CAUSED BY C6 FRACTURE IN A PATIENTWITH ANKYLOSING SPONDYLITIS: A CASE REPORT

Abstract

The “Chin-on-Chest” syndrome or fixed “chin-on-sternum” deformity, characterized by subaxial cervical kyphosis resulting from a C6 vertebral body fracture, is an uncommon manifestation in patients with ankylosing spondylitis. We present the case of a 66-year-old male admitted with an inability to maintain a horizontal gaze, open his mouth, or swallow. This progressively debilitating deformity led to complete functional dependence and impaired oral intake, increasing the risk of complications such as decubitus ulcers and spontaneous oesophageal rupture. Radiographs of the cervical segment of the spine revealed a C0-2 angle of 0° in flexion and 3° in extension, with a vertical angle between the chin and brow line of 49°. A two-stage surgical correction was planned: first stage – posterior kyphotic deformity correction with instrumented fixation and fusion, and second stage – anterior corpectomy and fusion. The first stage is posterior approach with instrumented fixation and fusion involving an occipital plate, C3/C4 lateral mass screws, and T2/ T3 pedicle screws to correct the kyphotic deformity and prevent further progression. The second stage is anterior approach with C6 corpectomy, anterior column reconstruction using a titanium mesh cage and cervical plate, followed by fusion, addressing the compromised anterior spinal column. This approach is mandatory in patients with ankylosing spondylitis due to low bone density. Postoperative CT imaging confirmed optimal correction of the kyphotic deformity, achieving a total correction angle of 55° and restoring the vertical chin-brow angle to 17°. This complex two-stage surgical intervention entails significant perioperative and intraoperative risks, including iatrogenic vertebral injuries, severe neurological deficits, and vascular complications. Despite a cardiovascular complication at the conclusion of surgery, the patient achieved an excellent anatomical correction of the subaxial cervical deformity.