Extended pedicle subtraction osteotomy in combination with novel four-rod technique in an ankylosing spondylitis patient with neglected thoracolumbar fracture: a case report

Abstract

Tin Trong Nguyen, Truc Tam Vu

Introduction: Ankylosing spondylitis is an autoimune disorder that affects mainly the enthesis of the spinal ligaments and capsules and causes a progressive fusing of the vertebra bodies. The ankylosed spine will lose the ability of absorbing and dissipating the axial loading force and therefore becomes vulnerable with injuries.

Case report: We report a 27-year-old male patient with past history of ankylosing spondylitis who suffered from a neglected thoracolumbar fracture after a traffic accident one year before admission. He noticed an ongoing kyphotic deformity over time to the point that he could not have a horizontal gaze at present. The full spine Xray depicted a severe kyphosis at L1/2 (80o ) due to a nonunion L1/2 flexion-distraction fracture. There were no neurological deficits at admission.

Surgical treatment and outcome: The patient underwent an extended L2 pedicle subtraction osteotomy and long instrumentation from T10 to L5. The clinical and radiological outcome were satisfactory as the global kyphosis was reduced from 80o to 20o and patient could regain his normal upright posture, even better than before the accident.

Conclusion: Kyphotic deformity in ankylosing spondylitis patients, especially with traumatic causes is always a challenge for spinal surgeons as corrective surgeries involve potential neurological complications. Conventional pedicle subtraction osteotomy remains a procedure of choice. The downside of this technique is the relatively high risk of non-union and implant failure which can be improved by reinforcing two additional short rods to the whole configuration.

PDF