PERCUTANEOUS INSTRUMENTATION WITHOUT ARTHRODESIS FOR THORACOLUMBAR BURST FRACTURES (A3/A4, B): A RETROSPECTIVE STUDY

ABSTRACT Objective: There is still no consensus as to the treatment options for thoracolumbar burst fractures, although these fractures are widely described in the literature. The aim of this study was to evaluate the clinical and radiological outcomes of percutaneous instrumentation without arthrodesis as a method of fixation of these lesions. Methods: This retrospective, cross-sectional study evaluated 16 patients by measuring regional kyphosis using the Cobb method and the scores for quality of life and return to work (Oswestry Disability Index, VAS, SF-36 and Denis). Results: Six months after surgical treatment, 62.5% of all patients showed minimal disability according to the Oswestry Disability Index, maintenance of regional kyphosis correction and no synthesis failure. Conclusions: The clinical and radiological outcomes of the study suggest that minimally invasive fixation is indicated for the treatment of thoracolumbar burst fractures. Level of evidence IV; Observational study: retrospective cohort.

Percutaneous instrumentation with cement augmentation for traumatic hyperextension thoracic and lumbar fractures in ankylosing spondylitis: a single-institution experience

OBJECTIVE The typical traumatic thoracolumbar (TL) fracture in patients with ankylosing spondylitis (AS) is a hyperextension injury involving all three spinal columns, which is associated with unfavorable outcomes. Although a consensus on the management of these highly unstable injuries is missing, minimally invasive surgery (MIS) has been progressively accepted as a treatment option, since it is related to lower morbidity and mortality rates. This study aimed to evaluate clinical and radiological outcomes after percutaneous instrumentation with cement augmentation for hyperextension TL fractures in patients with AS at a single institution. METHODS This cohort study was completed retrospectively. Back pain was assessed at preoperative, postoperative, and final follow-up visits using the visual analog scale (VAS). Patient-reported outcomes via the Oswestry Disability Index (ODI) and the new mobility score (NMS) were obtained to assess disability and mobility during follow-up. Radiological outcomes included the Cobb angle, sagittal index (SI), union rate, and implant failure. Intra- and postoperative complications were recorded. RESULTS A total of 22 patients met inclusion criteria. The mean patient age was 74.2 ± 7.3 years with a mean follow-up of 39.2 ± 17.4 months. The VAS score for back pain significantly improved over the follow-up period (from 8.4 ± 1.1 to 2.8 ± 0.8, p < 0.001). At the last follow-up, all patients had minor disability (mean ODI score 24.4 ± 6.1, p = 0.003) and self-sufficiency of mobility (mean NMS 7.5 ± 1.6, p = 0.02). The Cobb angle (5.2° ± 2.9° preoperatively to 4.4° ± 3.3° at follow-up) and SI (7.9° ± 4.2° to 8.8° ± 5.1°) were maintained at follow-up, showing no loss of segmental kyphosis. Bone union was observed in all patients. The overall complication rate was 9.1%, while the reoperation rate for implant failure was 4.5%. CONCLUSIONS Percutaneous instrumentation with cement augmentation for traumatic hyperextension TL fractures in AS demonstrated good clinical and radiological outcomes, along with a high bone union level and low reoperation rate. Accordingly, MIS reduced the complication rate in the management of these injuries of the ankylosed spine.

Percutaneous, PMMA-augmented, pedicle screw instrumentation of thoracolumbar ankylotic spine fractures

Introduction Fractures in the ankylotic spine may have an insidious presentation but are prone to displace with devastating consequences. The long lever arm of ankylosed spine fragments may lead to pulmonary and great vessel injury and is difficult to adequately immobilize. Conservative treatment will produce in many cases poor outcomes with high morbidity and mortality. Open surgical treatment is also fraught with technical difficulties and can lead to major blood loss and prolonged operative times. In recent years, percutaneous instrumentation of non-ankylotic spine fractures has gained popularity, producing similar outcomes to open surgery with shorter operative times and reduced blood loss and hospital length of stay. We describe our experience implementing these techniques in ankylotic spine patients. Methods We retrospectively retrieved from our hospital’s electronic health records all patients treated for thoracolumbar spine fractures between 2008 and 2015 with a diagnosis of ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH). Operative and postoperative data, results, and complications were tabulated, and radiographic parameters were evaluated. Results Twenty-four patients with ankylotic spine disease underwent percutaneous augmented instrumentation between 2008 and 2015. The mean age was 76. All patients had at least one comorbidity. The mean number of ankylosed levels was 14. Mean operative time was 131 min. The average postoperative hemoglobin decrease was 1.21 gr/%, with only 4 patients requiring blood transfusion. 45.8% of the patients had postoperative medical complications. One patient (4.2%) had a superficial postoperative infection, and one patient died in hospital. The average hospital length of stay was 14.55 days. All patients retained their preoperative ASIA grades, and 3 improved one grade. All patients united their fractures without losing reduction. Conclusions PMMA-augmented percutaneous instrumentation is an attractive surgical option for this difficult patient subset, especially when compared to other available current alternatives.

Open versus percutaneous instrumentation in thoracolumbar fractures: magnetic resonance imaging comparison of paravertebral muscles after implant removal

OBJECTIVEPercutaneous instrumentation in thoracolumbar fractures is intended to decrease paravertebral muscle damage by avoiding dissection. The aim of this study was to compare muscles at instrumented levels in patients who were treated by open or percutaneous surgery.METHODSTwenty-seven patients underwent open instrumentation, and 65 were treated percutaneously. A standardized MRI protocol using axial T1-weighted sequences was performed at a minimum 1-year follow-up after implant removal. Two independent observers measured cross-sectional areas (CSAs, in cm2) and region of interest (ROI) signal intensity (in pixels) of paravertebral muscles by using OsiriX at the fracture level, and at cranial and caudal instrumented pedicle levels. An interobserver comparison was made using the Bland-Altman method. Reference ROI muscle was assessed in the psoas and ROI fat subcutaneously. The ratio ROI-CSA/ROI-fat was compared for patients treated with open versus percutaneous procedures by using a linear mixed model. A linear regression analyzed additional factors: age, sex, body mass index (BMI), Pfirrmann grade of adjacent discs, and duration of instrumentation in situ.RESULTSThe interobserver agreement was good for all CSAs. The average CSA for the entire spine was 15.7 cm2 in the open surgery group and 18.5 cm2 in the percutaneous group (p = 0.0234). The average ROI-fat and ROI-muscle signal intensities were comparable: 497.1 versus 483.9 pixels for ROI-fat and 120.4 versus 111.7 pixels for ROI-muscle in open versus percutaneous groups. The ROI-CSA varied between 154 and 226 for open, and between 154 and 195 for percutaneous procedures, depending on instrumented levels. A significant difference of the ROI-CSA/ROI-fat ratio (0.4 vs 0.3) was present at fracture levels T12–L1 (p = 0.0329) and at adjacent cranial (p = 0.0139) and caudal (p = 0.0100) instrumented levels. Differences were not significant at thoracic levels. When adjusting based on age, BMI, and Pfirrmann grade, a significant difference between open and percutaneous procedures regarding the ROI-CSA/ROI-fat ratio was present in the lumbar spine (p < 0.01). Sex and duration of instrumentation had no significant influence.CONCLUSIONSPercutaneous instrumentation decreased muscle atrophy compared with open surgery. The MRI signal differences for T-12 and L-1 fractures indicated less fat infiltration within CSAs in patients who received percutaneous treatment. Differences were not evidenced at thoracic levels, where CSAs were smaller. Fat infiltration was not significantly different at lumbar levels with either procedure in elderly patients with associated discopathy and higher BMI. In younger patients, there was less fat infiltration of lumbar paravertebral muscles with percutaneous procedures.