Endoscopic decompression of severe post-tuberculosis kyphosis related ossification of the ligamentum flavum: case report and literature review.

PURPOSE: Spinal tuberculosis, if not promptly treated, can lead to kyphotic deformity, causing persistent neurological abnormalities and discomfort. Spinal cord compression can occur due to ossification of the ligamentum flavum (OLF) at the apex of kyphosis. Traditional surgical interventions, including osteotomy and fixation, pose challenges and risks. We present a case of thoracic myelopathy in a patient with post-tuberculosis kyphosis, successfully treated with biportal endoscopic spinal surgery (BESS). METHOD: A 73-year-old female with a history of untreated kyphosis presented with walking difficulties and lower limb pain. Imaging revealed a kyphotic deformity of 120° and OLF-induced cord compression at T8-9. UBE was performed under spinal anesthesia. Using the BESS technique, OLF was successfully removed with minimal damage to the stabilizing structures. RESULTS: The patient exhibited neurological improvement after surgery, walking on the first day without gait instability. Follow-up at 1 year showed no kyphosis progression or recurrence of symptoms. BESS successfully resolved the cord compression lesion with minimal blood loss and damage. CONCLUSION: In spinal tuberculosis-related OLF, conventional open surgery poses challenges. BESS emerges as an excellent alternative, providing effective decompression with reduced instrumentation needs, minimal blood loss, and preservation of surrounding structures. Careful patient selection and surgical planning are crucial for optimal outcomes in endoscopic procedures.

Simple and Reliable Magnetic Resonance Imaging Parameter to Predict Postoperative Ambulatory Function in Patients With Metastatic Epidural Spinal Cord Compression.

STUDY DESIGN: Retrospective case-control study. OBJECTIVES: The aim of this study was to develop a simple and reliable imaging parameter to predict postoperative ambulatory status in patients with metastatic epidural spinal cord compression (MESCC). METHODS: Sixty-three patients with MESCC underwent spine surgery because of neurologic deficits were included. On preoperative axial MRI, the cord compression ratio was analyzed for postoperative ambulatory status. The relationship between other imaging features, such as fracture of the affected vertebra and increased T2 signal intensity of the spinal cord at the compression level, and the postoperative ambulatory status were also analyzed. RESULTS: Cord compression ratio and increased T2 signal change of the spinal cord were significantly different between the postoperative ambulatory group and the non-ambulatory group. Receiver operating characteristic analysis showed that the optimal cut-off value was 0.84. In the multivariate regression analysis, only a cord compression ratio of more than 0.84 was significantly associated with postoperative ambulatory status (odds ratio = 10.80; 95% confidence interval = 2.79-41.86; P = .001). Interobserver/intraobserver agreements were strong for the cord compression ratio, however those agreements were weak for increased T2 signal intensity. CONCLUSIONS: On preoperative MRI, the cord compression ratio may predict postoperative ambulatory status in patients with MESCC. The measurement of this imaging parameter was simple and reliable. This imaging predictor may be helpful for both clinicians and patients.

Effects of bone cement augmentation for uppermost instrumented vertebra on adjacent disc segment degeneration in lumbar fusions.

OBJECTIVE: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects. METHODS: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed. RESULTS: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively. CONCLUSIONS: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.

Proximal Junctional Kyphosis According to the Type of Lumbar Degenerative Kyphosis Following Lumbosacral Long Fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to investigate proximal junctional kyphosis (PJK) after lumbosacral long fusion according to preoperative Roussouly and lumbar degenerative kyphosis (LDK) types. SUMMARY OF BACKGROUND DATA: Although previous studies have suggested some risk factors for PJK, the effects of preoperative grade of sagittal imbalance and paraspinal muscles degeneration on PJK remain unclear. METHODS: Eighty-seven patients who had undergone lumbosacral fusion more than five levels with available clinical and radiological data were enrolled. The presence of PJK defined as sagittal Cobb angle ≥20° between the uppermost instrumented vertebra (UIV) and two supra-adjacent vertebrae at postoperative 2-year radiographs was recorded. Its occurrence was compared according to preoperative Roussouly and LDK types (Takemistu type) and the degree of paraspinal muscle degeneration at the upper level of UIV. Other sagittal radiographic parameters were also measured. RESULTS: In this series, 28 patients (group I, 32.2%) showed radiological PJK, whereas 59 patients did not show radiological PJK (non-PJK patients, group II, 67.8%) at postoperative 2 years. PJK presented more prevalence in type III and type IV of LDK types (26/27, 96.3%). However, Roussouly types did not show any significant difference in PJK prevalence. In radiological parameters, a larger preoperative SVA (P = 0.018) and PI-LL (P = 0.015) were associated with PJK. Also, smaller quantity and lower quality of paraspinal muscles at T12-L1 level showed significant (P < 0.001) relationship with PJK. On multivariate logistic regression, higher LDK type (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 1.24-3.56), smaller quantity (OR: 1.03, 95% CI: 1.00-1.07), and higher degree of paraspinal muscle degeneration (OR: 1.46, 95% CI: 0.92-2.31) were independent predictors of postoperative PJK. CONCLUSION: Although various factors are related to PJK following long segment fusion, preoperative conditions such as LDK types and degree of paraspinal muscle degeneration might be related to the development of PJK.Level of Evidence: 3.

Sacral insufficiency fracture after instrumented lumbosacral fusion: Focusing pelvic deformation -A retrospective case series.

The purpose of this study was to report the characteristics of SIFs after ILSF and discuss its management focusing on pelvic deformation. We retrospectively reviewed all consecutive patients who underwent ILSF for degenerative disc diseases during the period between 2000 and 2017 and were diagnosed as SIF at our institute. The clinical and radiographic data were reviewed on their medical charts. Treatment outcomes for SIF were also investigated. Eight patients (all females) were included in this study. Mean age at SIF diagnosis was 72 years, and the mean follow-up period was 3.8 years (range 1-7 years). SIF developed average 7.5 years (range 1 month-17 years) after the index ILSF. Fracture patterns were unilateral vertical in four, bilateral vertical in three, and horizontal in 1 patient. Unlike patients with unilateral vertical SIF, patients with bilateral vertical or horizontal SIF showed a marked increase of pelvic incidence (PI) by mean 17.0°±5.0° and sagittal vertical axis (SVA) by mean 4.5 ± 2.2 cm, compared to the respective values before the onset of abrupt pain. All patients with unilateral vertical SIF were treated favorably by conservative management, however sacropelvic fixation was inevitable in patients with bilateral vertical or horizontal SIF. Bilateral vertical or horizontal SIF showed marked changes on sagittal radiographic parameters including PI and SVA. Although unilateral vertical SIF has benign courses that responded well to conservative management, bilateral vertical or horizontal SIF is likely to need surgical treatment. Treatment plan should be determined depending on fracture pattern and pelvic deformation.

Lumbar Interbody Fusion: Techniques, Pearls and Pitfalls.

Lumbar interbody fusion (LIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Currently, LIF can be performed with posterior, transforaminal, anterior, and lateral approaches by open surgery or minimally invasive surgery (MIS). Each technique has its own advantages and disadvantages. In general, posterior LIF is a well-established procedure with good fusion rates and low complication rates but is limited by the possibility of iatrogenic injury to the neural structures and paraspinal muscles. Transforaminal LIF is frequently performed using an MIS technique and has an advantage of reducing these iatrogenic injuries. Anterior LIF (ALIF) can restore the disk height and sagittal alignment but has inherent approach-related challenges such as visceral and vascular complications. Lateral LIF and oblique LIF are performed using an MIS technique and have shown postoperative outcomes similar to ALIF; however, these approaches carry a risk of injury to psoas, lumbar plexus, and vascular structures. Herein, we provide a detailed description of the surgical procedures of each LIF technique. We shall then consider the pearls and pitfalls, as well as propose surgical indications and contraindications based on the available evidence in the literatures.