Radiologic study of disc behavior following compression fracture of the thoracolumbar hinge managed by kyphoplasty: A 52-case series.

INTRODUCTION: Kyphoplasty has proved effective for durable correction of traumatic vertebral deformity following Magerl A fracture, but subsequent behavior of the adjacent discs is unclear. The objective of the present study was to analyze evolution according to severity of initial kyphosis and quality of fracture reduction. MATERIAL AND METHOD: A single-center prospective study included cases of single compression fracture of the thoracolumbar hinge managed by Kyphon Balloon Kyphoplasty with polymethylmethacrylate bone cement. Radiology focused on traumatic vertebral kyphosis (VK), disc angulation (DA) and disc height index (DHI) in the adjacent discs. Linear regression assessed the correlation between superior disc height index (SupDHI) and postoperative VK on the one hand and correction gain on the other, using the Student t test for matched pairs and Pearson correlation coefficient. RESULTS: Fifty-two young patients were included, with mean follow-up of 18.6 months. VK fell from 13.9° preoperatively to 8.2° at last follow-up. DHI found significant superior disc subsidence (P=0.0001) and non-significant inferior disc subsidence (P=0.116). DA showed significantly reduced superior disc lordosis (P=4*10(-5)). SupDHI correlated with VK correction (r=0.32). Preoperative VK did not correlate with radiologic degeneration of the adjacent discs. CONCLUSION: Correction of traumatic vertebral deformity avoids subsidence and loss of mechanical function in the superior adjacent disc. The underlying disc compensates for residual deformity. Balloon kyphoplasty is useful in compression fracture, providing significant reduction of traumatic vertebral deformity while conserving free and healthy adjacent discs. LEVEL OF EVIDENCE: IV.

Kyphopasty and vertebroplasty.

Vertebroplasty and balloon kyphoplasty are percutaneous techniques performed under radioscopic control. They were initially developed for tumoral and osteoporotic lesions; indications were later extended to traumatology for the treatment of pure compression fracture. They are an interesting alternative to conventional procedures, which are often very demanding. The benefit of these minimally invasive techniques has been demonstrated in terms of alleviation of pain, functional improvement and reduction in both morbidity and costs for society. The principle of kyphoplasty is to restore vertebral body anatomy gently and progressively by inflating balloons and then reinforcing the anterior column of the vertebra with cement. In vertebroplasty, cement is introduced directly under pressure, without prior balloon inflation. Both techniques can be associated to minimally invasive osteosynthesis in certain indications. In our own practice, we preferably use acrylic cement, for its biomechanical properties and resistance to compression stress. We use calcium phosphate cement in young patients, but only associated to percutaneous osteosynthesis due to the risk of secondary correction loss. The evolution of these techniques depends on improving personnel radioprotection and developing new systems of vertebral expansion.

Tibial plateau fractures: reproducibility of three classifications (Schatzker, AO, Duparc) and a revised Duparc classification.

INTRODUCTION: Since the reproducibility of the Schatzker and AO tibial plateau fracture classification systems has already been assessed, the goal of this study was to evaluate the Duparc classification system and compare it to the other two. HYPOTHESES: CT scan is better than X-rays for analyzing and classifying tibial plateau fractures. The Duparc classification system is more effective than the other two systems but could be improved by adding elements of each. MATERIALS AND METHODS: Six observers analyzed images from 50 fractures and then classified them. Each fracture was evaluated on X-rays. Two weeks later, these same fractures were evaluated on X-rays and CT scans. The same process was repeated four weeks later. The Kappa coefficient (κ) was used to measure agreement and contingency tables were built. RESULTS: The interobserver reproducibility for the X-ray analysis was poor for the Duparc and AO classifications (κDuparc=0.365; κAO=0.357) and average for the Schatzker classification (κSchatzker=0.404). The reproducibility was improved overall when CT scans were also analyzed (κDuparc=0.474; κAO=0.479; κSchatzker=0.476). A significantly greater number of fractures could not be classified in the Schatzker system than in the others (14.3% versus 2% for Duparc and 7.33% for AO). Review of the contingency tables revealed that the Schatzker and AO classification systems did not take certain fracture types into account. Seventy-one percent (71%) of the lateral unicondylar split fractures were found to be combined fractures when CT scan analysis was added. DISCUSSION: Our results showed CT scan to be better at analyzing and classifying fractures. We also found the Duparc classification to be advantageous because it allowed more fractures to be classified than in other classification systems, while having similar reproducibility. Based on our study findings, the Duparc classification was revised by adding elements of the other two. We propose using the modified Duparc classification system to analyze tibial plateau fractures going forward. LEVEL OF EVIDENCE: Level IV. Retrospective study.

Evaluation of percutaneous surgery in the treatment of thoracolumbar fractures. Preliminary results of a prospective study on 65 patients.

INTRODUCTION: We conducted a prospective, single-center, continuous study of patients operated for fractures urelated to osteoporosis at the thoracolumbar junction level using percutaneous techniques. The aim of this study was to investigate the clinical and radiological outcomes of percutaneous techniques for these indications. PATIENTS AND METHODS: This study included patients who underwent standalone balloon kyphoplasty surgery or combined with percutaneous posterior osteosynthesis in cases of associated distraction. The fractures were classified according to the Magerl classification. The patients were evaluated clinically (visual analog scale [VAS], the Oswestry Disability Index, and autonomy) and radiologically (vertebral kyphosis and height variations of the vertebral body) for 12 months. RESULTS: Sixty-five patients were included. The mean age at the time of the surgery was 45.4 years (range, 19-72 years). The main indications were A.1 fractures of L1. We noted 22% cement leakages, none having a clinical impact. In the overall series, the VAS at the lesional level improved from 5.5 (range, 3-8) preoperatively to 0.6 (range, 1-3) at 12 months. In all, 95% of the workers resumed their occupation. Traumatic kyphosis improved from 13.3° (range, 5-23°) before the surgery to 8.3° (range, 1-20°). DISCUSSION: The complication rate was low. The radiological results are comparable to those reported in the literature for other series with percutaneous surgery. Only the loss of the correction observed in the group undergoing standalone kyphoplasty with calcium phosphate cement led us to propose another type of treatment for these indications. This study must be continued over the long term to detect the appearance of discopathy related to cement leakage and to answer questions as to how cement evolves. LEVEL OF EVIDENCE: III, prospective study with low statistical power.