USING A CONTROLLED REDUCTION MANOEUVRE AS AN ADJUNCT TO CERVICO-THORACIC OSTEOTOMY FOR CERVICO-THORACIC KYPHOSIS

Abstract

Introduction: We report the result of cervical osteotomy in 11 patients using a controlled reduction technique and assess the safety and efficacy of this operation. Methods: Between 1993 and 2006, 11 patients with ankylosing spondylitis underwent correction of cervical kyphosis utilizing an extension osteotomy at the C7/T1 junction. The procedure was carried out under general anaesthesia with spinal cord monitoring. Lateral mass screws were placed from C3–C6 and thoracic pedicle screws placed from T2 to T5. After completion of the osteotomy, the reduction manoeuvre was carried out by the senior surgeon lifting the halo, while bilateral temporary malleable rods (fixed to cervical lateral mass screws) were allowed to pass through top loading thoracic pedicle screws, before tightening by the assistant when the desired position had been achieved. The temporary malleable rods were then replaced with definitive rods, thereby creating a solid internal fixation. A halo vest was maintained for 12 weeks to support the instrumentation and allow the fusion mass to develop.

Results: Surgery was performed on 10 males and one female. The mean age at surgery was 56 years (range 40–74). Duration of symptoms averaged 2.7 years (range 1–5 yrs). The average duration of surgery was 4.7 hours (range 3–6.5) with a mean blood loss of 1938cc (range 1000–3600). The mean follow up was 6.5 years (range 2–13). The mean pre-op chin brow vertical angle was 54º (range 20–70) reducing to 7º (range 2–20) at final follow-up. The mean pre-operative kyphotic angle was 19.2º reducing to minus 34º at final follow up. Restoration of normal forward gaze was achieved in all cases. No patient suffered spinal cord injury or permanent nerve root palsy.

Conclusion: Cervico-thoracic osteotomy is a potentially hazardous procedure. The technique described reduces the risk of translation during the reduction manoeuvre thereby reducing the risk of serious neurological injury.