Significance of various risk factors for proximal junctional kyphosis and instability of instrumentation in surgical treatment for adult spinal deformities

Objective. To analyze the significance of the influence of various risk factors on the development of proximal junctional kyphosis (PJK) and instability of instrumentation.Material and Methods. The results of surgical treatment of 382 patients with scoliotic deformities of the lumbar spine of type I and IIIb according to Aebi were analyzed. Patients were operated on through the posterior approach using the TLIF-PLIF technique with extended rigid transpedicular instrumentation. Potential risk factors influencing the development of proximal junctional kyphosis and instability of instrumentation were analyzed.Results. It was found that only three risk factors significantly affect the development of PJK: correction of lumbar lordosis more than 30° (p = 0.036) increases the likelihood of its development by 1.5 times, osteoporosis (p = 0.001) – by 2.5 times, and proximal junctionalangle ≥10° (p = 0.001) – by 3.5 times. Three factors showed a statistically significant effect on the incidence of instrumentation instability: correction of lumbar lordosis more than 30° (p = 0.034) increases the likelihood of its occurrence by 1.7 times, osteoporosis (p = 0.018) – by 1.8 times, and deviation of the sagittal vertical axis by more than 50 mm (p = 0.001) – by 3.3 times.Conclusion. The most significant risk factors for the occurrence of PJK and instability of instrumentation are osteoporosis, correction of lumbar lordosis more than 30°, an increase in the proximal junctional angle ≥10°, and an anterior deviation of sagittal vertical axis more than 50 mm. Consideration of these factors in the preoperative period, as well as during surgery, can decrease likelihood of the occurrence of PJK and instability of instrumentation.

Evaluation of Outcome of Decompression and Transpedicular Screw Fixation in the Management of TB of the Thoracolumbar Spine

Introduction: Spinal tubercular infection is the most common and dangerous form of skeletal tuberculosis. Transpedicular instrumentation systems have distinct advantages such as rigid segmental fixation, stabilization of the three column of the spine, least failure at bone metal interface, early post-operative mobilization with efficient nursing care and least complications in the management of tuberculosis of the thoraco-lumbar spine. Objectives was to evaluate the outcome of decompression and transpedicular screw fixation in the management of tuberculosis of the thoracolumbar spine. Materials and Methods: An observational follow-up study. A total no. of 21 patients aged between 19-72 years and both sexes (Male-9, Female-12) was included in the study. Patients diagnosed as tuberculosis of the thoraco-lumbar spine were operated by direct decompression, transpedicular screw fixation and fusion with bone graft and mesh cage in some cases. First follow-up at 1 month after operation and thereafter at 3 and 6 months follow-up was done. Results: This study shows mean±SD age was 40±11.29 years. 57.1% were female and 42.9% were male. Lesion 66.7% were dorsal, 19.0% were lumbar and 14.3% were dorsolumbar. 42.86% were ASIA grade C, 33.33% were ASIA grade D, 9.52% were both ASIA grade B & E and 4.76% were ASIA grade A in preoperative stage. On the other hand in postoperative 61.90% were ASIA grade E, 33.33% were ASIA grade D and 4.76% were ASIA grade B. The difference was statistically significant (P<0.001). Four-fifths (80.95) of the patients had excellent outcome followed by 14.29% good outcome, 4.76% fair and 0% poor outcome. Conclusions: Posterior approach is a minimum surgical intervention that encourages neurological recovery. Medicine Today 2020 Vol.32(2): 104-111

Deformity Correction Through the Use of Reduction Towers: 2-Dimensional Operative Video

Spinal deformity management can be difficult. The decision for surgery, approach, number of levels, and surgical technique all present challenges. Even when other issues are managed appropriately the process of how to correct the deformity needs special consideration. Numerous techniques have been studied including vertebra-to-rod, rod de-rotation, 3-rod-techniques, and cantilever maneuvers. While cantilever is the preferred technique when treating sagittal plane deformity, scoliosis often requires a combination of techniques due to the complexity of deformity in coronal and transverse planes. This video illustrates an adult scoliosis correction using sequential reduction towers and de-rotation techniques. Using this method the step of hook holders is eliminated and tension is distributed evenly across the rod using sequential reduction of the reduction towers across the length of the rod. This has led to a very efficient correction of our deformity as well as a powerful de-rotation tool. We routinely use this technique for flexible and rigid deformities, which is assessed pre-op with a computed tomography. The patient is a 67-yr-old female with prior lumbar decompressions and worsening back pain with radiculopathy. No significant sagittal malalignment is present but pelvic tilt is elevated and a coronal deformity exists. pelvic incidence measures 59°, LL50°, PT28° and lumbar scoliosis shows a coronal Cobb angle of 50.8°. Briefly, surgery involved transpedicular instrumentation from T10-S1 with bilateral iliac screw fixation. To achieve mobility posterior column osteotomies were performed at T12-L1, L1-2, L2-3, L3-4, L4-5, and L5-S1 levels. TLIF was performed at L4-5, L5-S1 for fusion. Postoperative scoliosis X-rays demonstrated improved sagittal and coronal alignment with PI59°, LL59°, PT22°, and coronal Cobb angle of 12°.

Rates of Upper Facet Joint Violation in Minimally Invasive Percutaneous and Open Instrumentation: A Comparative Cohort Study of Different Insertion Techniques

Background Minimally invasive pedicle screw placement may have a higher incidence of violation of the superior cephalad unfused facet joint. Study Aims We investigated the incidence and risk factors of upper facet joint violation in percutaneous robot-assisted instrumentation versus percutaneous fluoroscopy-guided and open transpedicular instrumentation. Methods A retrospective study including all consecutive patients who underwent lumbar instrumentation, fusion, and decompression for spondylolisthetic stenosis and degenerative disk disease was conducted between January 2012 and January 2016. All operations were performed by the same surgeon; the patients were divided into three groups according to the method of instrumentation. Group 1 involved the robot-assisted instrumentation in 58 patients, group 2 consisted of 64 patients treated with a percutaneous transpedicular instrumentation using fluoroscopic guidance, and 72 patients in group 3 received an open midline approach for pedicle screw insertion. Results Superior segment facet joint violation occurred in 2 patients in the robot-assisted group 1 (7%), in 22 of the percutaneous fluoroscopy-guided group 2 (34%), and in 6 cases of the open group (8%). The incidence of facet joint violation was present in 5% (3) of the screws in group 1, 22% (28) of the screws in group 2, and 3% (4) of the screws in group 3. Conclusion Meticulous surgical planning of the appropriate entry site (Weinstein's method), trajectory planning, and proper robot-assisted instrumentation of pedicle screws reduced the risk of superior segment facet joint violation.