INTERIM EVALUATION OF PROSPECTIVE MULTI-CENTRE OUTCOME STUDY OF ANTERIOR LUMBAR PLATING FOR ONE AND TWO LEVEL DEGENERATIVE DISC DISEASE

Abstract

We present our experience with the use of the Anterior Tension Band plate (ATB) following ALIF, which utilises the existing surgical approach obviating the need for posterior fixation. The ATB is a small, smooth, low profile plate. It can be placed through the existing approach (anterolateral retroperitoneal or anterior transperitoneal) across the reconstructed level to prevent extension of the graft space and anterior migration of the spacer. The primary objective of this study is to measure radiographic fusion success in patients with lumbar degenerative disc disease using the ATB system. The secondary objective is to accurately define the clinical benefits to the patient.

This is a prospective multi-center outcome study. Each patient was treated with an ATB plate at one or two levels between L2 & S1 and 1 ALIF or FRA allograft spacer per level. Patient data (VAS Pain, SF-12 and Oswestry) was collected preoperatively, and at six, twelve and twenty-four month post-operative intervals. Fusion was evaluated upon demonstration of bridging trabecular bone through or external to the femoral ring. Secondary endpoint success includes demonstration of 15% improvement over baseline on the VAS, Oswestry and SF-12 patient questionnaires.

To date one hundred and thirty-one patients have undergone surgery. There were ninety-two (70%) single-level ALIF procedures and thirty-nine (30%) two-level ALIF procedures. Patients that have returned for twelve month follow-up (n=41) have had a fusion success rate of 81%. The fusion rate among one-level patients is 89% (n=25) and 67% (n=15) among two-level patients. Four of five of the un-fused two-level patients had one level fused but not the other. At twelve months, Oswestry scores improved by an average of 40% with thirty-one of forty-seven (66%) patients achieving success and VAS scores improved by 42% with thirty-five of forty-seven (75%) being successful.

Preliminary analysis of current data shows positive outcomes using the ATB plating system in ALIF procedures. Primary and secondary outcomes are compatible with current standards of care, and device related complications are minimal. Further analysis of outcome data including will be reported upon the completion of the study.