Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients ...with spine fusions can increase the risk of dislocation risk after THA.
We identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m
(19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated.
Dislocation in the fusion group was 5.2% at one year versus 1.7% in controls but this did not reach statistical significance (HR 1.9; p = 0.33). Compared with controls, there was no significant difference in rate of dislocation in patients without a sacral fusion. When the sacrum was involved, the rate of dislocation was significantly higher than in controls (HR 4.5; p = 0.03), with a trend to more dislocations in longer lumbosacral fusions. Patient demographics and surgical characteristics of THA (i.e. surgical approach and femoral head diameter) did not significantly impact risk of dislocation (p > 0.05). Significant radiological differences were measured in mean anterior pelvic tilt between the one-level lumbar fusion group (22°), the multiple-level fusion group (27°), and the sacral fusion group (32°; p < 0.01). Ten-year survival was 93% in the fusion group and 95% in controls (HR 1.2; p = 0.8).
Lumbosacral spinal fusions prior to THA increase the risk of dislocation within the first six months. Fusions involving the sacrum with multiple levels of lumbar involvement notably increased the risk of postoperative dislocation compared with a control group and other lumbar fusions. Surgeons should take care with component positioning and may consider higher stability implants in this high-risk cohort.
STUDY DESIGN.Reliability and agreement study, retrospective case series.
OBJECTIVE.To develop a widely accepted, comprehensive yet simple classification system with clinically acceptable intra- and ...interobserver reliability for use in both clinical practice and research.
SUMMARY OF BACKGROUND DATA.Although the Magerl classification and thoracolumbar injury classification system (TLICS) are both well-known schemes to describe thoracolumbar (TL) fractures, no TL injury classification system has achieved universal international adoption. This lack of consensus limits communication between clinicians and researchers complicating the study of these injuries and the development of treatment algorithms.
METHODS.A simple and reproducible classification system of TL injuries was developed using a structured international consensus process. This classification system consists of a morphologic classification of the fracture, a grading system for the neurological status, and description of relevant patient-specific modifiers. Forty cases with a broad range of injuries were classified independently twice by group members 1 month apart and analyzed for classification reliability using the Kappa coefficient (κ).
RESULTS.The morphologic classification is based on 3 main injury patternstype A (compression), type B (tension band disruption), and type C (displacement/translation) injuries. Reliability in the identification of a morphologic injury type was substantial (κ= 0.72).
CONCLUSION.The AOSpine TL injury classification system is clinically relevant according to the consensus agreement of our international team of spine trauma experts. Final evaluation data showed reasonable reliability and accuracy, but further clinical validation of the proposed system requires prospective observational data collection documenting use of the classification system, therapeutic decision making, and clinical follow-up evaluation by a large number of surgeons from different countries.Level of Evidence4
➤ Sagittal alignment of the spine has gained attention in the field of spinal deformity surgery for decades. However, emerging data support the importance of restoring segmental lumbar lordosis and ...lumbar spinal shape according to the pelvic morphology when surgically addressing degenerative lumbar pathologies such as degenerative disc disease and spondylolisthesis.➤ The distribution of caudal lordosis (L4-S1) and cranial lordosis (L1-L4) as a percentage of global lordosis varies by pelvic incidence (PI), with cephalad lordosis increasing its contribution to total lordosis as PI increases.➤ Spinal fusion may lead to iatrogenic deformity if performed without attention to lordosis magnitude and location in the lumbar spine.➤ A solid foundation of knowledge with regard to optimal spinal sagittal alignment is beneficial when performing lumbar spinal surgery, and thoughtful planning and execution of lumbar fusions with a focus on alignment may improve patient outcomes.
Abstract Background context Traumatic fractures of the spine are most common at the thoracolumbar junction and can be a source of great disability. Purpose To review the most current information ...regarding the pathophysiology, injury pattern, treatment options, and outcomes. Study design Literature review. Methods Relevant articles, textbook chapters, and abstracts covering thoracolumbar spine fractures with and without neurologic deficit from 1960 to the present were reviewed. Results The thoracolumbar spine represents a unique system from a skeletal as well as neurological standpoint. The rigid rib-bearing thoracic spine articulates with the more mobile lumbar spine at the thoracolumbar junction (T10 - L2), the site of most fractures. A complete examination includes a careful neurologic examination of both motor and sensory systems. CT scans best describe bony detail while MRI is most efficient at describing soft tissues and neurological structures. The most recent classification system is that of the new Thoracolumbar Injury Classification and Severity Score. The different fracture types include compression fractures, burst fractures - both stable and unstable -, flexion-distraction injuries and fracture dislocations. Their treatment, both operative and non-operative depends on the degree of bony compromise, neurological involvement, and the integrity of the posterior ligamentous complex. Minimally invasive approaches to the care of thoracolumbar injuries have become more popular, thus, the evidence regarding their efficacy is presented. Finally, the treatment of osteoporotic fractures of the thoracolumbar spine is reviewed, including vertebroplasty and kyphoplasty, their risks and controversies, and senile burst fractures, as well. Conclusions Thoracolumbar spine fractures remain a significant source of potential morbidity. Advances in treatment have minimized the invasiveness of our surgery and in certain stable situations, eliminated it all together.
Introduction
Aging spine is characterized by facet joints arthritis, degenerative disc disease, bone remodeling and atrophy of extensor muscles resulting in a progressive kyphosis of the lumbar ...spine.
Objective
The aim of this paper is to describe the different compensatory mechanisms for patients with severe degenerative lumbar spine.
Material and methods
According to the severity of the imbalance, three stages are observed: balanced, balanced with compensatory mechanisms and imbalanced. For the two last stages, the compensatory mechanisms permit to limit the consequences of loss of lumbar lordosis on global sagittal alignment and therefore contribute to keep the sagittal balance of the spine.
Results
The basic concept is to extend adjacent segments of the kyphotic spine allowing for compensation of the sagittal unbalance but potentially inducing adverse effects.
Conclusion
Finally, we propose a three-step algorithm to analyze the global balance status and take into consideration the presence of the compensatory mechanisms in the spinal, pelvic and lower limb areas.
STUDY DESIGN.Systematic review and meta-analysis.
OBJECTIVE.To compare the efficacy of the use of either bisphosphonates or teriparatide on radiographic and functional outcomes of patients that had ...thoracolumbar spinal fusion.
SUMMARY OF BACKGROUND DATA.Controversy exists as to whether bisphosphonates interfere with successful spinal arthrodesis. An alternative osteoporosis medication is teriparatide, a synthetic parathyroid hormone that has an anabolic effect on osteoblast function. To date, there is limited comparative data on the influence of bisphosphonates or teriparatide on spinal fusion.
METHODS.A systematic search of medical reference databases was conducted for comparative studies on bisphosphonate or teriparatide use after thoracolumbar spinal fusion. Meta-analysis was performed using the random-effects model for heterogeneity. Radiographic outcomes assessed include fusion rates, risk of screw loosening, cage subsidence, and vertebral fracture.
RESULTS.No statistically significant differences were noted between bisphosphonates and control groups regarding fusion rate and risk of screw loosening (fusionodds ratio OR = 2.2, 95% confidence interval CI0.87–5.56, P = 0.09; looseningOR = 0.45, 95% CI0.14–1.48, P = 0.19). Teriparatide use was associated with higher fusion rates than bisphosphonates (OR = 2.3, 95% CI1.55–3.42, P < 0.0001). However, no statistically significant difference was noted between teriparatide and bisphosphonates regarding risk of screw loosening (OR = 0.37, 95% CI0.12–1.18, P = 0.09). Lastly, bisphosphonate use was associated with decreased odds of cage subsidence and vertebral fractures compared to controls (subsidenceOR = 0.29, 95% CI 0.11–0.75, P = 0.01; fractureOR = 0.18, 95% CI 0.07–0.48, P = 0.0007).
CONCLUSION.Bisphosphonates do not appear to impair successful spinal fusion compared to controls although teriparatide use is associated with higher fusion rates than bisphosphonates. In addition, bisphosphonate use is associated with decreased odds of cage subsidence and vertebral fractures compared to controls that had spinal fusion.Level of Evidence3
BACKGROUND:The selection of the lowest instrumented vertebra (LIV) in patients with adolescent idiopathic scoliosis (AIS) is still controversial. Although multiple radiographic methods have been ...proposed, there is no universally accepted guideline for appropriate selection of the LIV. We developed a simple and reproducible method for selection of the LIV in patients with Lenke type-1 (main thoracic) and 2 (double thoracic) curves and investigated its effectiveness in producing optimal positioning of the LIV at 5 years of follow-up.
METHODS:The radiographs for 299 patients with Lenke type-1 or 2 AIS curves that were included in a multicenter database were evaluated after a minimum duration of follow-up of 5 years. The “touched vertebra” (TV) was selected on preoperative radiographs by 2 independent examiners. The LIV on postoperative radiographs was compared with the preoperative TV. The final LIV position in relation to the center sacral vertical line (CSVL) was assessed. The CSVL-LIV distance and coronal balance in patients who had fusion to the TV were compared with those in patients who had fusion cephalad and caudad to the TV. The sagittal plane was also reviewed.
RESULTS:In 86.6% of patients, the LIV was selected at or immediately adjacent to the TV. Among patients with an “A” lumbar modifier, those who had fusion cephalad to the TV had a significantly greater CSVL-LIV distance than those who had fusion to the TV (p = 0.006) or caudad to the TV (p = 0.002). In the groups with “B” (p = 0.424) and “C” (p = 0.326) lumbar modifiers, there were no differences among the TV groups.
CONCLUSIONS:We recommend the TV rule as a third modifier in the Lenke AIS classification system. Selecting the TV as the LIV in patients with Lenke type-1 and 2 curves provides acceptable positioning of the LIV at long-term follow-up. The position of the LIV was not different when fusion was performed caudad to the TV but came at the expense of fewer motion segments. Patients with lumbar modifier “A” who had fusion cephalad to the TV had greater translation of the LIV, putting these patients at risk for poor long-term outcomes.
LEVEL OF EVIDENCE:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
OBJECTIVE There has been a recent renewed interest in the use and potential applications of 3D printing in the assistance of surgical planning and the development of personalized prostheses. There ...have been few reports on the use of 3D printing for implants designed to be used in complex spinal surgery. METHODS The authors report 2 cases in which 3D printing was used for surgical planning as a preoperative mold, and for a custom-designed titanium prosthesis: one patient with a C-1/C-2 chordoma who underwent tumor resection and vertebral reconstruction, and another patient with a custom-designed titanium anterior fusion cage for an unusual congenital spinal deformity. RESULTS In both presented cases, the custom-designed and custom-built implants were easily slotted into position, which facilitated the surgery and shortened the procedure time, avoiding further complex reconstruction such as harvesting rib or fibular grafts and fashioning these grafts intraoperatively to fit the defect. Radiological follow-up for both cases demonstrated successful fusion at 9 and 12 months, respectively. CONCLUSIONS These cases demonstrate the feasibility of the use of 3D modeling and printing to develop personalized prostheses and can ease the difficulty of complex spinal surgery. Possible future directions of research include the combination of 3D-printed implants and biologics, as well as the development of bioceramic composites and custom implants for load-bearing purposes.
PDF
