Vertebral body reconstruction system B-Twin(®) versus corset following non-osteoporotic Magerl A1.2 thoracic and lumbar fracture. Functional and radiological outcome at 12 month follow-up in a prospective randomized series of 50 patients

NTRODUCTION: Kyphoplasty and percutaneous vertebroplasty are two effective procedures for osteoporotic vertebral compression fractures, but there have been few publications on their use in non-osteoporotic forms. B-Twin(®) vertebral body reconstruction is a new minimally invasive vertebral body reconstruction technique developed for non-osteoporotic vertebral compression fractures of the thoracolumbar junction and lumbar spine. OBJECTIVES: The present study describes this novel technique and assessed efficacy compared to a conservative method. PATIENTS AND METHODS: Inclusion criteria were: Magerl type A1.2 non-osteoporotic thoracolumbar or lumbar spinal compression fractures in patients aged over 18 years, free of neurologic compromise. Patients were randomized to management by corset (group 1) or by the B-Twin(®) spacer (group 2). Follow-up used a visual analog scale (VAS) to assess pain, the Oswestry Disability Index (ODI) and, on radiology, the vertebral (VK) and regional (RK) kyphosis angles and anterior and medial height indices at baseline, 3 months and 12 months. RESULTS: Group 1 comprised 26 patients; group 2 comprised 24 patients, with 44 implants. In group 1, mean VK was 10.7° (± 1.73°) at baseline, 11.9° (± 1.56°) at 3 months and 12.3° (± 1.6°) at 12 months. Mean RK was respectively 9.7° (± 0.97°), 11.10° (± 1.07°) and 11.8° (± 1.27). Mean medial height (medial-to-posterior [MH/PH] height ratio was respectively 0.75 [±0.05], 0.70 [±0.06] and 0.65 [±0.04]). Mean anterior height (anterior-to-posterior [AH/PH] height ratio) was respectively 0.79 [± 0.06], 0.76 [± 0.05] and 0.73 [± 0.05]). Mean VAS score was respectively 8.6 (± 0.52), 3.8 (± 0.82) and 2.3 (± 0.83). In group 2, mean VK was 13.8° (± 0.47°) at baseline, 4.88° (± 0.65°) at 3 months and 4.88° (± 0.65°). Mean RK was respectively 9.82° (± 1.67°), 4.47° (± 0.86°) and 4.82° (± 0.98°). Mean MH/PH ratio was respectively 0.69 (± 0.05), 0.86 (± 0.03) and 0.86 (± 0.03). Mean AH/PH ratio was respectively 0.73 (± 0.04), 0.90 (± 0.03) and 0.90 (± 0.03). Mean VAS score was 8.88 (± 0.47) at baseline, 2 (± 1) at 1-day post-surgery, 1.71 (± 0.88) at 3 months and 1.12 (± 0.23) at 12 months. The increase in vertebral body height in patients managed by B-Twin(®) was maintained at 6 and 12 months (P<0.0001). The study showed better results with the vertebral spacer than on conservative treatment, with a 95% reduction in bed-rest: 4-6 weeks in the conservative group vs. 2-3 days in the surgical group. CONCLUSIONS: The vertebral body reconstruction technique provided anatomic vertebral body reconstruction and quick return to household activity without resort to a corset. Deformity was durably reduced. At 12-month follow-up, pain reduction and stasis were achieved. The risk of injected cement leakage was slight.