The Hardware Failure and Correction Loss of Short-segment Pedicle Screw Fixation Combined With Transforaminal Interbody Fusion in Treatment of Unstable Thoracolumbar Burst Fracture: Retrospective Study in Vietnam

Background: Correction loss and hardware failure of short segment posterior pedicle screw fixation in treatment of thoracolumbar unstable burst fracture have been remaining a main concern. Several authors have introduced the procedures to solve these limitations including transforaminal interbody fusion (TIF). The purposes of this study were to evaluate the progressive kyphosis and implant failure of short-segment pedicle screw fixation combined with transforaminal interbody fusion in treatment of unstable thoracolumbar burst fracture.Methods: The retrospective study were enrolled in the patients with isolated unstable thoracolumbar burst fractures, Denis type IIB who were treated by posterior short fixation with TIF between January 2013 to January 2017. Patients were followed up for a minimum of one and half year. For evaluation of correction loss, % loss of anterior vertebral body heights (%AVB), vertebral kyphotic angle (VA) and regional kyphotic angle (RA) were collected preoperatively, postoperatively and at final follow-up. The hardware failure was assessed on radiological images at last follow-up. Results: There were 36 patients who met the inclusion criteria with a mean follow-up duration of 53 months. The mean correction loss of %AVB, VA and, RA were 10.2%, 2.9o and 5.6o, respectively. There were 6 patients (16.7%) with hardware failure at final follow-up. Conclusions: Short-segment posterior pedicle screw fixation with TIF using bone chip graft hasn’t prevented completely the hardware failure and progressive kyphosis in treatment of unstable thoracolumbar burst fracture.

Comparison of Outcomes between Minimally Invasive Lateral Approach Vertebral Reconstruction Using a Rectangular Footplate Cage and Conventional Procedure Using a Cylindrical Footplate Cage for Osteoporotic Vertebral Fracture

The aim of the current study was to compare outcomes between lateral access vertebral reconstruction (LAVR) using a rectangular footplate cage and the conventional procedure using a cylindrical footplate cage in patients with osteoporotic vertebral fracture (OVF). We included 46 patients who underwent anterior–posterior combined surgery for OVF: 24 patients underwent LAVR (Group L) and 22 underwent the conventional procedure (Group C). Preoperative, postoperative, and 1- and 2-year follow-up X-ray images were used to measure local lordotic angle, correction loss, and cage subsidence (>2 mm in vertebral endplate depression). In anterior surgery, the operation time was significantly shorter (183 vs. 248 min, p < 0.001) and the blood loss was significantly less (148 vs. 406 mL, p = 0.01) in Group L than in Group C. In Group C, two patients had anterior instrumentation failure. Correction loss was significantly smaller in Group L than in Group C (1.9° vs. 4.9° at 1 year, p = 0.02; 2.5° vs. 6.5° at 2 years, p = 0.04, respectively). Cage subsidence was significantly less in Group L than in Group C (29% vs. 80%, p < 0.001). LAVR using a rectangular footplate cage is an effective treatment for OVF to minimize surgical invasiveness and postoperative correction loss.

Is Complete Correction of Cervical Sagittal Malalignment Necessary During 4-Level Anterior Cervical Discectomy and Fusion Surgery in Patients With Kyphosis?

Study Design: Retrospective analysis. Objective: We investigated whether complete correction of cervical sagittal malalignment is necessary during 4-level anterior cervical discectomy and fusion (ACDF) in patients with kyphosis. Methods: This retrospective study included 84 patients who underwent 4-level ACDF surgery at a university hospital between January 2010 and December 2015. Based on the degree of cervical lordosis correction, patients were categorized into the following groups: mild (0-10°), moderate (10-20°), and complete correction (>20°). The clinical outcomes, radiological parameters, and functional outcomes were analyzed. Results: We observed no significant intergroup differences in the baseline characteristics. The cervical sagittal vertical axis (CSVA) correction loss at the final follow-up was lesser in the mild- and moderate- than in the complete-correction group. The spinocranial angle (SCA) and T1 slope (T1 S) were significantly higher in the moderate- and complete-correction groups than in the mild-correction group, 3 days postoperatively. The cervical proximal junctional kyphosis (CPJK), adjacent segment degeneration (ASD), and ASD following CPJK rates were higher in the complete-correction group. We observed no significant intergroup differences in postoperative complications; however, 5 patients showed internal fixation failure in the complete-correction group; 4 of these patients required reoperation. No significant intergroup difference was observed in the Japanese Orthopedic Association and neck disability index scores at any time point. Conclusions: A mild-to-moderate correction of cervical lordosis is superior to complete correction in patients with kyphosis who undergo 4-level ACDF because this approach is associated with lesser axial stress and CSVA correction loss.

Contribution of postoperative vertebral remodeling to reversal of vertebral wedging and prevention of correction loss in patients with adolescent Scheuermann’s kyphosis

OBJECTIVE This study aimed to investigate reversal of vertebral wedging and to evaluate the contribution of vertebral remodeling to correction maintenance in patients with adolescent Scheuermann’s kyphosis (SK) after posterior-only instrumented correction. METHODS A retrospective cohort study of patients with SK was performed. In total, 45 SK patients aged 10–20 years at surgery were included. All patients received at least 24 months of follow-up and had Risser sign greater than grade 4 at latest follow-up. Patients with Risser grade 3 or less at surgery were assigned to the low-Risser group, whereas those with Risser grade 4 or 5 were assigned to the high-Risser group. Radiographic data and patient-reported outcomes were collected preoperatively, immediately postoperatively, and at latest follow-up and compared between the two groups. RESULTS Remarkable postoperative correction of global kyphosis was observed, with similar correction rates between the two groups (p = 0.380). However, correction loss was slightly but significantly less in the low-Risser group during follow-up (p < 0.001). The ratio between anterior vertebral body height (AVBH) and posterior vertebral body height (PVBH) of deformed vertebrae notably increased in SK patients from postoperation to latest follow-up (p < 0.05). Loss of correction of global kyphosis was significantly and negatively correlated with increased AVBH/PVBH ratio. Compared with the high-Risser group, the low-Risser group had significantly greater increase in AVBH/PVBH ratio during follow-up (p < 0.05). The two groups had similar preoperative and postoperative Scoliosis Research Society–22 questionnaire scores for all domains. CONCLUSIONS Obvious reversal in wedge deformation of vertebrae was observed in adolescent SK patients. Patients with substantial growth potential had greater vertebral remodeling and less correction loss. Structural remodeling of vertebral bodies has a positive effect and protects against correction loss. These results could be help guide treatment decision-making.