Abstract
INTRODUCTION: We report a series of 90 patients enrolled in a prospective study of Dynesys stabilisation reviewed at 12 to 30 months.
The procedure involves, at each segment, cephalad and caudad pedicle screws connected with a polycarbo-urethane spacer and polyethylene cord. It achieves load relief and controlled flexion. Since 1996, 7000 procedures have been undertaken globally.
METHOD: Indications are analogous to consideration for fusion. Entry criteria included (1) unresolved and unacceptable lumbar back pain despite protracted conservative management and (2) definite pathology where symptoms could be abolished by anaesthetising the target segments.
Where root compression was present, a midline approach and posterior screw placement was used in conjunction with open decompression. With back pain alone a bilateral Wiltse approach and posterolateral placement was used.
All patients were assessed pre- and post-surgery with SF36, Oswestry Disability Index and pain analogue scores and Modified Zung. Standing radiographs were obtained post- surgery and at review. Follow-up was at six, 12, 24 and 52 weeks in addition to this review.
RESULTS: Follow-up was 100%. 89 patients survived. Mobilisation was achieved on day 1 and discharge usually by day 2. Based on the above outcome measures and patient satisfaction good to excellent results were achieved in 74% (66/89). Screw loosening or breakage occurred in 8%, and was associated with a poor result.
DISCUSSION: Dynesys flexible stabilisation offers a simple alternative to fusion with less potential for adjacent ‘Domino’ failure. It differs from tension ligament systems such as Graf. At this stage the results appear at least as good as a comparable cohort of fusion patients.
The present series is early, but gives grounds for encouragement. Screw loosening and failure are technical problems detracting from the result and require further development.
We are continuing to use the technique.
These abstracts were prepared by Dr Robert J. Moore. Correspondence should be addressed to him at Spine Society of Australia, Institute of Medical and Veterinary Science, The Adelaide Centre for Spinal Research, Frome Road, Adelaide, South Australia 5000.
