Selecting proper distal fusion level in severe thoracolumbar kyphosis secondary to late osteoporotic vertebral compression fracture to limit distal complications

Effect of romosozumab administration on proximal junctional kyphosis in corrective spinal fusion surgery

BACKGROUND CONTEXT

The effect of romosozumab administration in patients undergoing corrective spinal fusion surgery has not yet been analyzed.

PURPOSE

To examine the effect of romosozumab administration on reducing the incidence of proximal junctional kyphosis (PJK), particularly PJK due to fractures (PJK-Fx), in patients undergoing spinal corrective fusion surgery.

DESIGN

Retrospective cohort study.

PATIENT SAMPLE

A total of 111 patients aged >50 years underwent corrective fusion surgery (>2 vertebrae) for adult spinal deformity or vertebral compression fracture between June 2010 and July 2023.

OUTCOME MEASURES

The primary outcome was the incidence of PJK, whereas the secondary outcomes were changes in Hounsfield unit (HU) values, surgical complications, and clinical outcomes measured using the Japanese Orthopaedic Association (JOA) and visual analog scale scores.

METHODS

The patients were divided into the romosozumab (n=32) and nonromosozumab groups (n=79). Romosozumab was typically administered 2 months before surgery in the romosozumab group. Demographic data, surgery-related factors, and radiographic parameters were analyzed. HU values at the upper instrumented vertebra+1 (UIV+1) were measured preoperatively and at 1 year postoperatively. After the univariate analysis of preoperative factors associated with PJK, multivariate logistic regression was used to identify factors associated with PJK.

RESULTS

Romosozumab significantly increased the HU values at UIV+1 (-1.22% vs 13.60%, p<.001) and reduced the incidence of PJK (39.24% vs 18.75%, p=.046), particularly PJK-Fx (26.58% vs 6.25%, p=.019) and osteoporosis-related complications (55.70% vs 34.38%, p=.011). The multivariate analysis showed a significantly lower incidence of PJK (adjusted odds ratio = 0.32, p=.033), particularly PJK-Fx (adjusted odds ratio = 0.15, p=.018). There was a tendency for better JOA scores at 1 year postoperatively in the romosozumab group (21.49 vs 23.62, p=.071).

CONCLUSION

Romosozumab administration effectively increased bone density and reduced the risk of PJK, particularly PJK-Fx, and osteoporosis-related complications in patients undergoing corrective spinal fusion surgery. Administration of romosozumab 2 months before surgery enhanced bone mineral density and strength, leading to better surgical outcomes and fewer complications. Further long-term studies are needed to confirm these findings and optimize treatment protocols.

Offset sublaminar hook is an efficient tool for the prevention of distal junctional failure after kyphotic deformity correction

PURPOSE

To assess the radiological outcomes and complications focusing on distal junctional failure (DJF) of adult spinal deformity patients who underwent thoracolumbar fixation with the use of offset sublaminar hooks (OSH) distally.

METHODS

Retrospective review of a prospective, multicenter adult spinal deformity database (2 sites). Inclusion criteria were age of at least 18 years, presence of a spinal deformity with thoraco-lumbar instrumentation ending distally with OSH (pelvis excluded), with minimum 2 years of follow-up. Demographic data, spinopelvic parameters, functional outcomes and complications were collected. Data was analyzed using descriptive statistics. Statistical significance was set to p < 0.05.

RESULTS

32 patients met the inclusion criteria, with the main etiologies being Scheuermann kyphosis and post-traumatic kyphosis. There was a significant correction of thoracic or thoraco-lumbar kyphosis (from 83° to 45° in case of posterior column osteotomy, p < 0.001, and from 49° to 11° in case of a three-column osteotomy, p < 0.001). DJF occurred in 9.3% of the patients including 1 patient who presented distal hook dislodgement and 2 patients who presented a compression fracture below the lowest instrumented vertebra. Oswestry Disability Index score improved in the majority of the patients (from 34.3 to 18.1, p < 0.05).

CONCLUSIONS

This is the first paper to propose offset sublaminar hook as a safe and efficient tool for protection of the distal end of the construct in kyphotic ASD surgery when not going down to the pelvis. It showed satisfactory radiological and clinical outcome with an acceptable rate of complications and no distal junctional failure that required revision surgery.

Appropriate Use Criteria for Osteoporotic Compression Fractures

BACKGROUND CONTEXT

There is a lack of consensus regarding optimal indications for treatment of patients with osteoporotic vertebral fractures. An opportunity exists to improve outcomes if these indications can be clarified.

PURPOSE

The purpose of the North American Spine Society (NASS) Appropriate Use Criteria (AUC) was to determine the appropriate (i.e. reasonable) multidisciplinary treatment recommendations for patients with osteoporotic vertebral fractures across a spectrum of more common clinical scenarios.

STUDY DESIGN

A Modified Delphi process.

PATIENT SAMPLE

Modified consensus based guideline OUTCOME MEASURES: Final rating for treatment recommendations as either "Appropriate", "Uncertain", or "Rarely Appropriate" based on the median final rating among the raters.

METHODS

The methodology was based on the AUC development process established by the Research AND Development (RAND) Corporation. The topic of osteoporotic vertebral compression fracture was selected by NASS for its Clinical Practice Guideline development (CPG). In conjunction, the AUC committee determined key modifiers and adapted the standard definitions developed by the CPG with minimal modifications. A literature search and evidence analysis performed by the CPG were reviewed by the AUC work group. A separate multidisciplinary rating group was assembled. Clinical scenarios were generated based on a matrix of the modifiers, to rate the appropriateness of medical management, cement augmentation, or surgery. Based on the literature, provider experience, and group discussion, each scenario was scored on a nine-point scale on two separate occasions: once without discussion and again following discussion of the initial responses. The median rating for each scenario and level of agreement was then used to determine final indications as rarely appropriate with agreement (1 - 3), uncertain or disagreement (4-6), or appropriate with agreement (7-9). Consensus was not mandatory.

RESULTS

Medical management was appropriate across all scenarios. Cement augmentation was rarely appropriate in 60% of scenarios and uncertain or disagreement in 35% of scenarios. In the 5% of scenarios rated as appropriate with agreement for cement augmentation, high pain scores, acute duration, and simple fracture pattern were always present. Surgery was appropriate in 35% of scenarios and strongly influenced by instability and stenosis with neurological findings. Surgery was rarely appropriate in 18%, and uncertain or disagreement in 47% of scenarios.

CONCLUSIONS

Multidisciplinary appropriate treatment criteria for osteoporotic vertebral fractures were generated based on the RAND methodology. This document provides comprehensive evidence-based recommendations for evaluation and treatment of osteoporotic vertebral fractures. The document in its entirety will be found on the NASS website (https://www.spine.org/Research-Clinical-Care/Quality-Improvement/Appropriate-Use-Criteria).

The Association of Bone Mineral Density with Distal Junctional Kyphosis and Distal Junctional Failure After Multilevel Spine Fusions: A Systematic Review and Meta-Analysis

BACKGROUND

Distal junctional kyphosis (DJK) and distal junctional failure (DJF) are known complications of adult multilevel spinal fusion surgery. Previous literature has extensively investigated proximal junctional kyphosis and proximal junctional failure, but DJK and DJF are relatively understudied. This study investigates the association between bone mineral density (BMD) and DJK/DJF via a systematic review and meta-analysis.

METHODS

A literature search was conducted across PubMed, Cochrane, Web of Science, Embase, and Scopus to find studies reporting DJK, DJF, and BMD. A 12-month minimum follow-up and radiographic biomarker for BMD (Hounsfield units [HU] or a T-score) individually reported for each patient type were required for inclusion. Studies that did not report individualized biomarkers but provided averaged estimates of the effect of BMD on DJK/DJF development were used for systematic review.

RESULTS

Our search yielded 12 unique studies with 1094 patients, of which 5 studies with a total of 519 patients were suitable for comparison by meta-analysis. Patients who developed DJK/DJF had significantly lower HUs (113.17 ± 33.86) than patients who did not develop DJK/DJF (142.51 ± 41.39). No significant difference was found with regard to dual-energy X-ray absorptiometry measurements, age, or body mass index between patients who did and did not develop DJK/DJF.

CONCLUSIONS

Patients who developed DJK/DJF had significantly lower computed tomography-measured HU as compared to those without DJK/DJF. Our findings highlight the potential importance of BMD evaluation with computed tomography prior to multilevel spine fusion surgery, though further research would be helpful to evaluate the significance of dual-energy X-ray absorptiometry-based BMD measurements on DJK/DJF development.

Distal Junctional Failures in Degenerative Thoracolumbar Hyperkyphosis

OBJECTIVE

Degenerative thoracolumbar hyperkyphosis (DTH) is a disease that negatively affects individual health and requires surgical intervention, yet the ideal surgical approach and complications, especially distal junctional failures (DJF), remain poorly understood. This study aims to investigate DJF in DTH and to identify the risk factors for DJF so that we can improve surgical decision-making, and advance our knowledge in the field of spinal surgery to enhance patient outcomes.

METHODS

This study retrospectively reviewed 78 cases (late osteoporotic vertebral compression fracture [OVCF], 51; Scheuermann's kyphosis [SK], 17; and degenerative disc diseases [DDD], 10) who underwent corrective surgery in our institute from 2008 to 2019. Clinical outcomes were assessed using health-related quality of life (HRQOL) measures, including the visual analogue scale (VAS) scores for back and leg pain, the Oswestry disability index (ODI), and the Japanese Orthopaedic Association (JOA) scoring system. Multiple radiographic parameters, such as global kyphosis (GK) and thoracolumbar kyphosis (TLK), were assessed to determine radiographic outcomes. Multivariate logistic regression analysis was employed to identify the risk factors associated with DJF.

RESULTS

HRQOL improved, and GK, TLK decreased at the final follow-up, with a correction rate of 67.7% and 68.5%, respectively. DJF was found in 13 of 78 cases (16.7%), two cases had wedging in the disc (L3-4) below the instrumentation, one case had a fracture of the lowest instrumented vertebrae (LIV), one case had osteoporotic fracture below the fixation, nine cases had pull-out or loosening of the screws at the LIV and three cases (23.1%) required revision surgery. The DJF group had older age, lower computed tomography Hounsfield unit (CT HU), longer follow-up, more blood loss, greater preoperative sagittal vertical axis (SVA), and poorer postoperative JOA and VAS scores (back). The change in TLK level was larger in the non-DJF group. Post-sagittal stable vertebrae (SSV) moved cranially compared with pre-SSV.

CONCLUSION

Age, CT HU, length of follow-up, estimated blood loss, and preoperative SVA were independent risk factors for DJF. We recommend fixation of the two vertebrae below the apex vertebrae for DTH to minimize surgical trauma.

Short-Term Risk Factors for Distal Junctional Kyphosis after Spinal Reconstruction Surgery in Patients with Osteoporotic Vertebrae

STUDY DESIGN

Level 3 retrospective cohort case-control study.

PURPOSE

This study aimed to investigate the risk factors for distal junctional kyphosis (DJK) caused by osteoporotic vertebral fractures following spinal reconstruction surgery, with a focus on the sagittal stable vertebra.

OVERVIEW OF LITERATURE

Despite the rarity of reports on DJK in this setting, DJK was reported to reduce when the lower instrumented vertebra (LIV) was extended to the sagittal stable vertebra in the posterior corrective fixation for Scheuermann's disease.

METHODS

This study included 46 patients who underwent spinal reconstruction surgery for thoracolumbar osteoporotic vertebral fractures and kyphosis and were followed up for 1 year postoperatively. DJK was defined as an advanced kyphosis angle >10° between the LIV and one lower vertebra. The patients were divided into groups with and without DJK. The risk factors of the two groups, such as patient background, surgery-related factors, radiographic parameters, and clinical outcomes, were analyzed.

RESULTS

The DJK and non-DJK groups included 14 and 32 patients, respectively, without significant differences in patient background. Those with instability in the distal adjacent LIV disc had a significantly higher risk of DJK occurrence (28.6% vs. 3.2%, p=0.027). DJK occurrence significantly increased in those with the sagittal stable vertebra not included in the fixation range (57.1% vs. 18.8%, p=0.020). Other preoperative radiographic parameters were not significantly different. Instability in the distal adjacent LIV disc (adjusted odds ratio, 14.50; p=0.029) and the exclusion of the sagittal stable vertebra from the fixation range (adjusted odds ratio, 5.29; p=0.020) were significant risk factors for DJK occurrence.

CONCLUSIONS

Regarding spinal reconstruction surgery in patients with osteoporotic vertebral fractures, instability in the distal adjacent LIV disc and the exclusion of the sagittal stable vertebra from the fixation range were risk factors for DJK occurrence in the short term.