Spinal Instrumentation In Patients Research Articles

Impact of Spinal Instrumentation on Neurological Outcome in Patients with Intermediate Spinal Instability Neoplastic Score (SINS).

Simple SummarySpinal epidural metastases are a common complication of malignancies that can compromise spinal stability and subsequently lead to neurologic deficits in addition to pain and overall reduced quality of life, often requiring spinal instrumentation. The spinal instability neoplastic score is an instrument used to evaluate spinal stability; a stable situation is assumed in cases of a SINS below 7 and instability in cases of a SINS above 12, but there is uncertainty in SINS 7 to 12. Our aim was to evaluate the benefit of spinal instrumentation in these cases in terms of neurological function in order to improve patient treatment.Background: Adequate assessment of spinal instability using the spinal instability neoplastic score (SINS) frequently guides surgical therapy in spinal epidural osseous metastases and subsequently influences neurological outcome. However, how to surgically manage ‘impending instability’ at SINS 7–12 most appropriately remains uncertain. This study aimed to evaluate the necessity of spinal instrumentation in patients with SINS 7–12 with regards to neurological outcome. Methods: We screened 683 patients with spinal epidural metastases treated at our interdisciplinary spine center. The preoperative SINS was assessed to determine spinal instability and neurological status was defined using the Frankel score. Patients were dichotomized according to being treated by instrumentation surgery and neurological outcomes were compared. Additionally, a subgroup analysis of groups with SINS of 7–9 and 10–12 was performed. Results: Of 331 patients with a SINS of 7–12, 76.1% underwent spinal instrumentation. Neurological outcome did not differ significantly between instrumented and non-instrumented patients (p = 0.612). Spinal instrumentation was performed more frequently in SINS 10–12 than in SINS 7–9 (p < 0.001). The subgroup analysis showed no significant differences in neurological outcome between instrumented and non-instrumented patients in either SINS 7–9 (p = 0.278) or SINS 10–12 (p = 0.577). Complications occurred more frequently in instrumented than in non-instrumented patients (p = 0.016). Conclusions: Our data suggest that a SINS of 7–12 alone might not warrant the increased surgical risks of additional spinal instrumentation.

Sidebar: Community-driven Approaches to Preventing Overdoses Among American Indians.

### BACKGROUND AND PURPOSE: Spinal instrumentation plays a key role in the treatment of spinal instability in patients with metastatic tumors. Poor bone quality, radiation, and diffuse osseous tumor involvement present significant challenges to spinal stabilization with instrumentation and occasionally result in postinstrumentation compression fractures. Vertebral cement augmentation has been effective in the treatment of painful tumor-related compression fractures. Our objective was to describe cement augmentation options in the treatment of vertebral compression fractures associated with spinal instrumentation in patients with metastatic tumors. ### MATERIALS AND METHODS: Patients who underwent percutaneous vertebral cement augmentation in the treatment of instrumentation-associated vertebral compression fractures between 2005 and 2011 were included in the analysis. Only fractures that occurred within the construct or at an adjacent level were included. The change in Visual Analog Scale and need for further surgery were analyzed. ### RESULTS: Eleven patients met the inclusion criteria, with 8 tumors located in the thoracic spine and 3 tumors in the lumbar spine. The median time between instrumented surgery and vertebral augmentation was 5 months (1--48 months) and the median follow-up after cement augmentation was 24 months (4--59 months). A total of 22 vertebrae that were either within or immediately adjacent to the surgical instrumentation underwent vertebral augmentation. All patients reported a decrease in their pain scores (mean decrease: 6 Visual Analog Scale points; *P* \< .003). One patient required reoperation after cement augmentation. None of the patients experienced vertebral cement augmentation--related complications. ### CONCLUSIONS: Vertebral cement augmentation represents a safe and effective treatment option in patients with recurrent or progressive back pain and instrumentation-associated vertebral compression fractures.

GAIT DISORDERS IN PATIENTS WITH INSTRUMENTED NEUROMUSCULAR SCOLIOSIS

ABSTRACT Introduction: The effect of spinal fusion on gait in patients with neuromuscular scoliosis continues to be a controversial issue, especially in patients where the spinal fusion extends to the pelvis. Objective: To evaluate the effect of spinal instrumentation in these patients. Methods: We evaluated 34 patients in a retrospective study. The mean age at surgery was 14±3 years and only ambulatory patients who presented neuromuscular scoliosis and non-progressing neurogenic pathology were included. The patients were surgically treated by posterior spinal fusion with or without extension to the pelvis. Preoperative (PRE) and postoperative (POP) Rx were measured. Ambulatory potential was clinically examined in all the patients, and 10 patients were assessed by full-gait analysis. Results: The minimum POP follow-up was 2 years (2006-2016). Nine patients were instrumented to the pelvis when the obliquity was greater than 15°; the remaining patients were treated using the same fusion-level criteria as those applied for idiopathic scoliosis. All patients maintained their gait, with improvements in coronal and sagittal balance, transfers and sitting skills, physical appearance, and in some cases, gait speed. Conclusions: Spinal instrumentation in ambulatory patients with neuromuscular scoliosis, including procedures with extension to the pelvis, provides adequate correction and preserves ambulatory function. Level of evidence III; Retrospective case control study.

Incidence and Predictors of Hardware Failure After Instrumentation for Spine Metastasis: A Single-Institutional Series

We report a retrospective analysis of hardware failure in patients requiring instrumentation for spinal metastasis. In a retrospective study at a single institution, we identified 58 patients who underwent spinal instrumentation for metastasis from 2012 to 2018. Hardware failure was defined as screw pullout/loosening, cage migration, progressive kyphosis, or an otherwise-noticeable instrumentation deficit detectable on imaging. Risk factors for hardware failure with a P < 0.05 in in univariate were included in multivariate logistic regression models controlled for age, sex, and previously identified risk factors for hardware failure. In total, 58 patients required instrumentation for metastatic spine disease. Median age was 60.2 years (interquartile range 49.0-66.3), 38 patients (65.5%) were male, and median follow-up was 8.1 months (interquartile range 3.1-20.7). Eight patients (13.8%) developed signs of hardware failure during follow-up, of whom 2 patients (3.4%) underwent operative revision. In univariate analysis, Eastern Cooperative Oncology Group performance status >2 (P= 0.049) and multiple myeloma lesions (P= 0.010) were significant predictors of failure. Both factors maintained significance in a multivariate logistic regression model controlled for age, sex, history of spine radiation, and number of fused levels with P= 0.047; odds ratio 12.7 (95% confidence interval 1.03-156.4) for Eastern Cooperative Oncology Group performance status over 2 and P= 0.012; odds ratio 31.5 (95% confidence interval 2.2-460.0) for multiple myeloma lesions. The rate of hardware failure in this cohort was 13.8%, although operative revision rate was 3.4%. Spinal instrumentation in patients with poor preoperative functional status or multiple myeloma may be more likely to develop instrumentation failure.

The outcome following spinal instrumentation in haemodialyzed patients with pyogenic spondylodiscitis.

The aim of this study was to evaluate the outcome of spinal instrumentation in haemodialyzed patients with native pyogenic spondylodiscitis. Spinal instrumentation in these patients can be dangerous due to rates of complications and mortality, and biofilm formation on the instrumentation. A total of 134 haemodialyzed patients aged more than 50 years who underwent surgical treatment for pyogenic spondylodiscitis were included in the study. Their mean age was 66.4 years (50 to 83); 66 were male (49.3%) and 68 were female (50.7%). They were divided into two groups according to whether spinal instrumentation was used or not. Propensity score matching was used to attenuate the potential selection bias. The outcome of treatment was compared between these two groups. A total of 89 patients (66.4%) underwent non-instrumented surgery and 45 (33.5%) underwent instrumented surgery. There were no significant differences in the rates of postoperative complications, except for an increased rate of wound problems in the instrumented group, which was found in the unmatched cohorts (p = 0.034). There were no significant differences in the rate of recurrent infections (p = 0.328 for the unmatched cohort; p = 0.269 for the matched cohort) and mortality rate, including in-hospital (p = 0.713 for the unmatched cohort; p = 0.738 for the matched cohort) and one-year rates (p = 0.363 for the unmatched cohort; p = 0.787 for the matched cohort), between the groups. However, the interval between the initial diagnosis and the first recurrence was significantly longer in the instrumented group (p = 0.008 for the unmatched cohort; p = 0.032 for the matched cohort). Instrumented surgery for haemodialyzed patients with pyogenic spondylodiscitis showed similar outcomes, including recurrence and mortality, to non-instrumented surgery, despite the instrumented group having more severe neurological deficit, a larger number of involved levels, and increased kyphotic angle.

Therapeutic Outcomes of Hematogenous Vertebral Osteomyelitis With Instrumented Surgery

Patients with hematogenous vertebral osteomyelitis (HVO) occasionally require instrumentation for spinal stabilization. However, placing instrumentation in the setting of spinal infection raises concerns about recurrent infection due to bacteria adhering to the foreign material. In this study, we evaluated the therapeutic outcomes of patients with HVO who underwent instrumented surgery. We conducted a retrospective chart review of adult patients with microbiologically diagnosed HVO who underwent surgical intervention in 5 tertiary care hospitals over an 8-year period. A total of 153 patients with HVO underwent surgical management for their infections. Of these 153 patients, 94 (61.4%) underwent surgical debridement alone (noninstrumented surgery) and 59 (38.6%) underwent surgical debridement and instrumentation (instrumented surgery). The median durations of antibiotic therapy were 66 and 80 days for the noninstrumentation and instrumentation groups, respectively (P = .22). Clinical outcomes were similar between the groups, including rates of infection-related death (2.1% vs 0%; P = .52), primary failure (1.1% vs 5.1%; P = .30), and recurrence (4.8% vs 6.8%; P = .72). Among the instrumentation group, there was a significant decreasing trend for recurrence according to total duration of antibiotic therapy: 22.2% (4-6 weeks), 9.1% (6-8 weeks), and 2.6% (≥ 8 weeks; P = .04). Duration of pre-instrumentation antibiotic therapy and single-stage operation (vs 2-stage operation) were not risk factors for recurrence. Spinal instrumentation in patients with HVO may be safe with pathogen-directed prolonged antibiotic therapy and should not be abandoned or delayed solely because of the risk of recurrence.

Cement salvage of instrumentation-associated vertebral fractures.

Spinal instrumentation plays a key role in the treatment of spinal instability in patients with metastatic tumors. Poor bone quality, radiation, and diffuse osseous tumor involvement present significant challenges to spinal stabilization with instrumentation and occasionally result in postinstrumentation compression fractures. Vertebral cement augmentation has been effective in the treatment of painful tumor-related compression fractures. Our objective was to describe cement augmentation options in the treatment of vertebral compression fractures associated with spinal instrumentation in patients with metastatic tumors. Patients who underwent percutaneous vertebral cement augmentation in the treatment of instrumentation-associated vertebral compression fractures between 2005 and 2011 were included in the analysis. Only fractures that occurred within the construct or at an adjacent level were included. The change in Visual Analog Scale and need for further surgery were analyzed. Eleven patients met the inclusion criteria, with 8 tumors located in the thoracic spine and 3 tumors in the lumbar spine. The median time between instrumented surgery and vertebral augmentation was 5 months (1-48 months) and the median follow-up after cement augmentation was 24 months (4-59 months). A total of 22 vertebrae that were either within or immediately adjacent to the surgical instrumentation underwent vertebral augmentation. All patients reported a decrease in their pain scores (mean decrease: 6 Visual Analog Scale points; P < .003). One patient required reoperation after cement augmentation. None of the patients experienced vertebral cement augmentation-related complications. Vertebral cement augmentation represents a safe and effective treatment option in patients with recurrent or progressive back pain and instrumentation-associated vertebral compression fractures.

Growth-Sparing Spinal Instrumentation in Skeletal Dysplasia

Retrospective case series. To report the outcomes of distraction-based, growth-sparing spinal instrumentation in patients with skeletal dysplasia. Patients with skeletal dysplasia with spinal deformity often undergo early fusion, further compromising an already small chest. Nonfusion techniques may provide a safe alternative and allow for thoracic growth. Between 2004 and 2010, 12 children with a diagnosis of various types of skeletal dysplasia underwent growth-sparing spinal instrumentation for severe spinal deformities. The mean duration of treatment with growing rods was 57 months (42-84 mo). Nine patients were treated with growing rods (8 dual, 1 single), and 3 were treated with vertical expandable prosthetic titanium rib (VEPTR; Synthes). Preoperative, initial postoperative, and final follow-up anteroposterior and lateral spine radiographs were measured for magnitude of deformity, junctional kyphosis, and implant failure. The major curve Cobb angle improved from a mean of 79° preoperatively to a mean of 41° at the last follow-up (52%). There was a decrease in mean thoracic kyphosis from 77° preoperatively to 64° at final follow-up and an increase in mean lumbar lordosis from 58° preoperatively to 63° at final follow-up. The mean space available for the lungs increased by 26 mm on the concave and 24 mm on the convex side. Six patients required revision surgery for proximal junctional kyphosis. There were 4 rod failures and 6 hook and 8 screw dislodgements. One patient with vertical expandable prosthetic titanium rib had failed rib fixation that required revision. Growth-sparing spinal instrumentation in patients with skeletal dysplasia and severe spinal deformity has a high complication and revision rate, and surgeons should closely monitor these patients. The complication rate is comparable with previous reports on patients with other diagnoses. However, deformities were well controlled, some trunk growth was achieved, and fusion surgery was delayed in all cases. 4.

Influence of screw type on initial coronal and sagittal radiological correction with hybrid constructs in adolescent idiopathic scoliosis. Correction priorities

Pedicle screw constructs for spinal instrumentation in patients with adolescent idiopathic scoliosis (AIS) are effective in providing coronal plane correction but can result in loss of kyphosis, which in turn can lead to loss of lordosis. Hybrid constructs have been found superior over pedicle screw constructs in terms of thoracic kyphosis restoration. In this study, our objective was to compare outcomes with monoaxial versus polyaxial screws in an AIS population treated with hybrid constructs. Monoaxial screws provide better correction in the coronal plane but result in loss of thoracic kyphosis, whereas thoracic kyphosis is preserved when polyaxial screws are used. We retrospectively analysed data from 60 patients (mean age, 15years) with Lenke 1, 2, or 3 AIS treated using a hybrid construct with self-retaining bilaminar hook claws cranially, pedicle screws between the last instrumented vertebra and T11 caudally, and sublaminar universal clamps between the two extremities of the construct. Monoaxial screws were used in the first 30 patients (MS group) and polyaxial screws in the next 30 patients (PS group). Student's t test was performed to compare the two groups in terms of thoracic Cobb angle correction and T4-T12 kyphosis 3 months after surgery. No significant preoperative differences were found between the two groups. At last follow-up, the residual Cobb angle was significantly greater in the PS group than in the MS group (20.3° versus 15°) with a percentage of correction of 72.1% in the MS group versus 64.8% in the PS group. In the sagittal plane, the thoracic kyphosis was significantly greater in the PS group than in the MS group (26.6° versus 23°). This preliminary study shows that, even within a population managed using hybrid constructs, which are associated with less iatrogenic hypokyphosis, differences exist according to the technique used. The importance of sagittal spinal balance has been abundantly documented in the literature, and sagittal malalignment, particularly due to iatrogenic factors, is associated with poorer clinical outcomes in adults with spinal deformities. Therefore, there is a critical need to determine whether the treatment priority is optimal correction in the coronal plane or in the sagittal plane. We believe that the main focus should be sagittal plane correction, even at the expense of a slight decrease in coronal plane correction. Long-term studies are needed to confirm our preliminary findings.

Shortening of a Unit Rod Protruding Into the Hip Joint

A unit rod is a well-accepted method of posterior spinal instrumentation in patients with cerebral palsy (CP). Several types of complications after the use of a unit rod were reported, including penetration through the medial wall of the pelvis. A patient who underwent anterior and posterior spinal fusion with unit-rod instrumentation was found to have penetration of the unit rod into a dysplastic hip joint. The pelvic limb of the rod was shortened with a burr through an anterolateral approach to the iliac bone. This procedure was associated with a lower blood loss than was previously reported for revisions of unit rods. There was no need for hardware removal and therefore no loss of correction. The unit rod may be shortened before surgery to prevent this problem. The described procedure is a simple way of correcting penetration of a unit-rod limb into the hip joint.

Consensus Summary on the Diagnosis and Treatment of Osteoporosis

Consensus Summary on the Diagnosis and Treatment of Osteoporosis

Comparison of Cotrel-Dubousset and Harrington Rod Instrumentations in Idiopathic Scoliosis

An analysis of the efficacy of two techniques of posterior spinal instrumentation in patients with idiopathic scoliosis was performed. Thirty-two consecutive patients treated with Cotrel-Dubousset instrumentation and no external bracing were compared with 30 consecutive patients treated with Harrington rod instrumentation supplemented by Bobechko hooks, sublaminar wires, and postoperative bracing. The groups were similar in age, curve magnitude, and type. Cotrel-Dubousset instrumentation demonstrated significantly improved immediate frontal plane correction. It was also more effective in improving thoracic kyphosis, particularly in patients with preoperative hypokyphosis. Both procedures were performed with similar operative time, blood loss, and minimal complication rates.