108 - Unipedicular-Screw Index Vertebra Manipulation Technique for Minimally Invasive Short-Segment Thoracolumbar Fracture Fixation

Introduction: MIS spine surgery has revolutionized fixation of thoracolumbar fractures with burst elements. Recent studies have proven that percutaneous pedicle screw instrumentation is as effective as open instrumentation, with reduction in intraoperative blood loss and operative duration. Techniques such as short-segment pedicle screw fixation including the fractured vertebra has shown satisfactory radiological correction and functional outcomes, avoiding the need for extensile posterior constructs. In the present study, we describe our technique utilizing unipedicular index vertebra fixation and manipulation in minimally invasive surgery (MIS) for thoracolumbar fractures with burst elements. To the author’s knowledge, this technique is not well described in literature as open approaches are often adopted for the above.

Aim: We aim to highlight the two-year radiological & functional outcomes of 20 consecutive patients who underwent this technique.
Patients and

Methods: A retrospective review of prospectively collected data was conducted on 20 patients with thoracolumbar fractures with burst elements who underwent fixation using our technique. Patient data collected included demographic characteristics, mechanism of injury, associated injuries, neurological deficit at time of admission with pre- & post-operative neurological evaluation and length of hospital stay. Radiological investigations included plain radiographs, CT-spine with reconstruction and MRI-spine which provided data for radiological fracture classifications such as AO Spine and derivation of TLICS score, as well as preoperative planning. Radiological investigations in the postoperative period were carried out by standing radiographs or EOS whole spine at each postoperative follow-up up to two years. Radiological parameters - vertebral wedge angle, regional kyphosis angle, coronal cobb angle, anterior and posterior vertebral body heights were recorded at preoperative, intraoperative, postoperative, and up to 2-year follow-up. Clinical outcome scores of VAS and ODI were also recorded at similar time-points.

Results: Radiological outcomes reflect significant lordotic corrections of the vertebral wedge angles up to 2-year follow-up when compared to preoperative values (intraoperative:p=0.06; postoperative:p=0.001; 3-month:p=0.002; 6-month:p=0.004; 1-year:p=0.011; 2-year:p=0.016). Additionally, significant lordotic corrections of regional kyphosis angles (intraoperative:p=0.00; postoperative:p=0.00; 3-month:p=0.031; 6-month:p=0.039) and increases in anterior vertebral body heights (postoperative:p=0.001; 3-month:p=0.010; 6-month:p=0.020) up to 6-month follow-up was found. Preoperatively, median VAS of 85 (range 30 to 100) and ODI of 90 (range 40 – 98) were recorded. Statistically significant improvements in VAS and ODI were found across all timepoints when compared to preoperative values, with a mean VAS of 11.5 (S.D 4.8) and ODI of 9.9 (S.D 4.5) at 2-year follow-up.

Conclusion: Surgical management of thoracolumbar fractures with or without neurological deficit has a role in reducing nursing requirements and postoperative morbidity in patients with polytrauma and other associated injuries. Our approach in treating thoracolumbar fractures with burst elements using MIS short-segment fixation and unipedicular screw manipulation technique shows satisfactory radiological correction & high rates of fracture union, whilst reducing approach-related morbidity & improving functional outcomes.