Prediction of the Hamstring Graft Size for ACL Reconstruction Using Different Axial Layers in Preoperative MRI.

BACKGROUND: In ACL reconstruction, it is desirable to assess preoperatively whether a sufficient graft diameter can be achieved with the planned tendon graft. The present study investigated the effect of the location of the cross-sectional area (CSA) measurement of the hamstring tendons in preoperative MRI on the correlation of the CSA with the intraoperative graft diameter. In addition, we analyzed whether the measurement results of examiners with different skill levels were comparable. METHODS: A total of 32 subjects undergoing a single bundle ACL reconstruction using an autologous ipsilateral quadrupled hamstring graft (STGT) were included. The CSA of the semitendinosus and gracilis tendon was determined in preoperative MRI on six defined levels by three examiners. The intraclass correlation coefficient between the measurements of these observers was determined. The correlation between the sum of the CSA of both tendons (CSA STGT) and the graft diameter was investigated. RESULTS: The interrater reliability was excellent on most of the investigated levels. A significant correlation between CSA STGT and the graft diameter was seen on all levels. The strongest correlation was found on the level 10 mm above the joint line. CONCLUSIONS: The measurement of the CSA STGT in the preoperative MRI 10 mm above the joint line enabled a good assessment of the achievable graft diameter in ACL reconstruction, independent of the examiners' training level.

Freehand Technique for Pedicle Screw Placement during Surgery for Adolescent Idiopathic Scoliosis Is Associated with Less Ionizing Radiation Compared to Intraoperative Navigation.

PURPOSE: We aim to compare radiation exposure and implant-related complications of the freehand (FH) technique versus intraoperative image-guided navigation (IN) for pedicle screw placement in adolescent idiopathic scoliosis (AIS) and estimate associated lifetime attributable cancer risks. METHODS: A retrospective analysis of prospectively collected data from 40 consecutive AIS patients treated with pedicle screw instrumentation using the FH technique was performed. The dose area product (DAP) and effective dose (ED) were calculated. Screw-related complications were analysed, and the age- and gender-specific lifetime attributable cancer risks were estimated. The results were compared to previously published data on IN used during surgery for AIS. RESULTS: There were no implant-related complications in our cohort. Implant density was 86.6%. The mean Cobb angle of the main curve was 75.2° (SD ± 17.7) preoperatively and 27.7° (SD ± 10.8) postoperatively. The mean ED of our cohort and published data for the FH technique was significantly lower compared to published data on the IN technique (p < 0.001). The risk for radiogenic cancer for our FH technique AIS cohort was 0.0014% for male patients and 0.0029% for female patients. Corresponding risks for IN were significantly higher (p < 0.001), ranging from 0.0071 to 0.124% and from 0.0144 to 0.253% for male and female patients, respectively. CONCLUSION: The routine use of intraoperative navigation in AIS surgery does not necessarily reduce implant-related complications but may increase radiation exposure to the patient.

Impact of different surgical and non-surgical interventions on health-related quality of life after thoracolumbar burst fractures without neurological deficit: protocol for a comprehensive systematic review with network meta-analysis.

INTRODUCTION: There is no international consensus on how to treat thoracolumbar burst fractures (TLBFs) without neurological deficits. The planned systematic review with network meta-analyses (NMA) aims to compare the effects on treatment outcomes, focusing on midterm health-related quality of life (HRQoL). METHODS AND ANALYSIS: We will conduct a comprehensive and systematic literature search, identifying studies comparing two or more treatment modalities. We will search MEDLINE, EMBASE, Google Scholar, Scopus and Web of Science from January 2000 until July 2023 for publications. We will include (randomised and non-randomised) controlled clinical trials assessing surgical and non-surgical treatment methods for adults with TLBF. Screening of references, data extraction and risk of bias (RoB) assessment will be done independently by two reviewers. We will extract relevant studies, participants and intervention characteristics. The RoB will be assessed using the revised Cochrane RoB V.2.0 tool for randomised trials and the Newcastle-Ottawa Scale for controlled trials. The OR for dichotomous data and standardised mean differences for continuous data will be presented with their respective 95% CIs. We will conduct a random-effects NMA to assess the treatments and determine the superiority of the therapeutic approaches. Our primary outcomes will be midterm (6 months to 2 years after injury) overall HRQoL and pain. Secondary outcomes will include radiological or clinical findings. We will present network graphs, forest plots and relative rankings on plotted rankograms corresponding to the treatment rank probabilities. The ranking results will be represented by the area under the cumulative ranking curve. Analyses will be performed in Stata V.16.1 and R. The quality of the evidence will be evaluated according to the Grading of Recommendations, Assessment, Development and Evaluations framework. ETHICS AND DISSEMINATION: Ethical approval is not required. The research will be published in a peer-reviewed journal.

Clinical and Radiological Outcome of Disc Arthroplasty for the Treatment of Cervical Spondylotic Myelopathy.

INTRODUCTION: The aim of this study is to evaluate the clinical and radiological results of cervical disc arthroplasty (CDA) in patients with cervical spondylotic myelopathy (CSM) using the CP ESP® disc prosthesis. MATERIALS AND METHODS: Prospectively collected data of 56 patients with CSM have been analyzed. The mean age at surgery was 35.6 years (range: 25-43 years). The mean follow-up was 28.2 months (range: 13-42 months). The range of motion (ROM) of the index segments, as well as upper and lower adjacent segments, was measured before surgery and at final follow-up. The C2-C7 sagittal vertical axis (SVA), C2-C7 cervical lordosis (CL), and T1 slope minus cervical lordosis (T1s-CL) were analyzed as well. Pain intensity was measured preoperatively and during follow-up using an 11-point numeric rating scale (NRS). Modified Japanese Orthopaedic Association (mJOA) score was assessed preoperatively and during follow-up for the clinical assessment of myelopathy. Surgical and implant-associated complications were analyzed as well. RESULTS: The NRS pain score improved from a mean of 7.4 (±1.1) preoperatively to a mean of 1.5 (±0.7) at last follow-up (p < 0.001). The mJOA score improved from a mean of 13.1 (±2.8) preoperatively to a mean of 14.8 (±2.3) at last follow-up (p < 0.001). The mean ROM of the index levels increased from 5.2° (±3.0) preoperatively to 7.3° (±3.2) at last follow-up (p < 0.05). Four patients developed heterotopic ossifications during follow-up. One patient developed permanent dysphonia. CONCLUSIONS: CDA showed good clinical and radiological outcome in this cohort of young patients. The motion of index segments could be preserved. CDA may be a viable treatment option in selected patients with CSM.

Novel AI-Based Algorithm for the Automated Computation of Coronal Parameters in Adolescent Idiopathic Scoliosis Patients: A Validation Study on 100 Preoperative Full Spine X-Rays.

STUDY DESIGN: Retrospective, mono-centric cohort research study. OBJECTIVES: The purpose of this study is to validate a novel artificial intelligence (AI)-based algorithm against human-generated ground truth for radiographic parameters of adolescent idiopathic scoliosis (AIS). METHODS: An AI-algorithm was developed that is capable of detecting anatomical structures of interest (clavicles, cervical, thoracic, lumbar spine and sacrum) and calculate essential radiographic parameters in AP spine X-rays fully automatically. The evaluated parameters included T1-tilt, clavicle angle (CA), coronal balance (CB), lumbar modifier, and Cobb angles in the proximal thoracic (C-PT), thoracic, and thoracolumbar regions. Measurements from 2 experienced physicians on 100 preoperative AP full spine X-rays of AIS patients were used as ground truth and to evaluate inter-rater and intra-rater reliability. The agreement between human raters and AI was compared by means of single measure Intra-class Correlation Coefficients (ICC; absolute agreement; >.75 rated as excellent), mean error and additional statistical metrics. RESULTS: The comparison between human raters resulted in excellent ICC values for intra- (range: .97-1) and inter-rater (.85-.99) reliability. The algorithm was able to determine all parameters in 100% of images with excellent ICC values (.78-.98). Consistently with the human raters, ICC values were typically smallest for C-PT (eg, rater 1A vs AI: .78, mean error: 4.7°) and largest for CB (.96, -.5 mm) as well as CA (.98, .2°). CONCLUSIONS: The AI-algorithm shows excellent reliability and agreement with human raters for coronal parameters in preoperative full spine images. The reliability and speed offered by the AI-algorithm could contribute to the efficient analysis of large datasets (eg, registry studies) and measurements in clinical practice.

In Vitro Characterization of a Tissue Renin-Angiotensin System in Human Nucleus Pulposus Cells.

Low back pain is a clinically highly relevant musculoskeletal burden and is associated with inflammatory as well as degenerative processes of the intervertebral disc. However, the pathophysiology and cellular pathways contributing to this devastating condition are still poorly understood. Based on previous evidence, we hypothesize that tissue renin-angiotensin system (tRAS) components, including the SARS-CoV-2 entry receptor angiotensin-converting enzyme 2 (ACE2), are present in human nucleus pulposus (NP) cells and associated with inflammatory and degenerative processes. Experiments were performed with NP cells from four human donors. The existence of angiotensin II, angiotensin II type 1 receptor (AGTR1), AGTR2, MAS-receptor (MasR), and ACE2 in human NP cells was validated with immunofluorescent staining and gene expression analysis. Hereafter, the cell viability was assessed after adding agonists and antagonists of the target receptors as well as angiotensin II in different concentrations for up to 48 h of exposure. A TNF-α-induced inflammatory in vitro model was employed to assess the impact of angiotensin II addition and the stimulation or inhibition of the tRAS receptors on inflammation, tissue remodeling, expression of tRAS markers, and the release of nitric oxide (NO) into the medium. Furthermore, protein levels of IL-6, IL-8, IL-10, and intracellular as well as secreted angiotensin II were assessed after exposing the cells to the substances, and inducible nitric oxide synthase (iNOS) levels were evaluated by utilizing Western blot. The existence of tRAS receptors and angiotensin II were validated in human NP cells. The addition of angiotensin II only showed a mild impact on gene expression markers. However, there was a significant increase in NO secreted by the cells. The gene expression ratios of pro-inflammatory/anti-inflammatory cytokines IL-6/IL-10, IL-8/IL-10, and TNF-α/IL-10 were positively correlated with the AGTR1/AGTR2 and AGTR1/MAS1 ratios, respectively. The stimulation of the AGTR2 MAS-receptor and the inhibition of the AGTR1 receptor revealed beneficial effects on the gene expression of inflammatory and tissue remodeling markers. This finding was also present at the protein level. The current data showed that tRAS components are expressed in human NP cells and are associated with inflammatory and degenerative processes. Further characterization of the associated pathways is warranted. The findings indicate that tRAS modulation might be a novel therapeutic approach to intervertebral disc disease.

Artificial Intelligence-Driven Prediction Modeling and Decision Making in Spine Surgery Using Hybrid Machine Learning Models.

Healthcare systems worldwide generate vast amounts of data from many different sources. Although of high complexity for a human being, it is essential to determine the patterns and minor variations in the genomic, radiological, laboratory, or clinical data that reliably differentiate phenotypes or allow high predictive accuracy in health-related tasks. Convolutional neural networks (CNN) are increasingly applied to image data for various tasks. Its use for non-imaging data becomes feasible through different modern machine learning techniques, converting non-imaging data into images before inputting them into the CNN model. Considering also that healthcare providers do not solely use one data modality for their decisions, this approach opens the door for multi-input/mixed data models which use a combination of patient information, such as genomic, radiological, and clinical data, to train a hybrid deep learning model. Thus, this reflects the main characteristic of artificial intelligence: simulating natural human behavior. The present review focuses on key advances in machine and deep learning, allowing for multi-perspective pattern recognition across the entire information set of patients in spine surgery. This is the first review of artificial intelligence focusing on hybrid models for deep learning applications in spine surgery, to the best of our knowledge. This is especially interesting as future tools are unlikely to use solely one data modality. The techniques discussed could become important in establishing a new approach to decision-making in spine surgery based on three fundamental pillars: (1) patient-specific, (2) artificial intelligence-driven, (3) integrating multimodal data. The findings reveal promising research that already took place to develop multi-input mixed-data hybrid decision-supporting models. Their implementation in spine surgery may hence be only a matter of time.

Revision surgery for incomplete resection or recurrence of cervical spine chordoma: a consecutive case series of 24 patients.

PURPOSE: Chordomas are rare tumors with an annual incidence of approximately one per million. Chordomas rarely metastasize but show a high local recurrence rate. Therefore, these patients present a major clinical challenge, and there is a paucity of the literature regarding the outcome after revision surgery of cervical spine chordomas. Available studies suggest a significantly worse outcome in revision scenarios. The purpose of this study is to analyze the survival rate, and complications of patients that underwent revision surgery for local recurrence or incomplete resection of chordoma at the craniocervical junction or at the cervical spine. METHODS: 24 consecutive patients that underwent revision surgery for cervical spine chordoma remnants or recurrence at a single center were reviewed retrospectively. We analyzed patient-specific surgical treatment strategies, complications, and outcome. Kaplan-Meier estimator was used to analyze five-year overall survival. RESULTS: Gross total resection was achieved in 17 cases. Seven patients developed dehiscence of the pharyngeal wall, being the most common long-term complication. No instability was observed. Postoperatively, four patients received proton beam radiotherapy and 12 patients had combined photon and proton beam radiotherapy. The five-year overall survival rate was 72.6%. CONCLUSION: With thorough preoperative planning, appropriate surgical techniques, and the addition of adjuvant radiotherapy, results similar to those in primary surgery can be achieved.

Magnetically controlled growing rods in early onset scoliosis: radiological results, outcome, and complications in a series of 22 patients.

INTRODUCTION: Magnetically controlled growing rods (MCGR) for the surgical treatment of early onset scoliosis (EOS) allow non-invasive outpatient based distractions during spinal growth. The purpose of this study is to present the results of a single center case series of 22 patients, evaluate the effect of MCGR treatment on the development of spino-pelvic parameters during growth, and report initial outcomes after end of treatment. MATERIALS AND METHODS: Prospectively collected data of 22 EOS patients with MCGR treatment has been analyzed. The following radiological parameters were measured before index surgery, after index surgery, 1 year after index surgery, and at last follow-up: Cobb angle of the major curves, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Mean age at index surgery was 9.5 years (range: 4-14 years). Mean length of follow-up was 47.6 months (range: 25-121 months). Etiology of diagnosis was idiopathic in 14 patients, associated with neurofibromatosis in 2 patients, and neuromuscular or syndromic in 6 patients. RESULTS: Mean Cobb angle of the major curve was 57° preoperatively and 29° at last follow-up (p < 0.0005). Mean TK was 20.1° preoperatively and 20° at last follow-up (p > 0.05). Mean LL was 52.8° preoperatively and 53.2° at last follow-up (p > 0.05). Mean PI was 43.2° preoperatively and 46.3° at last follow-up (p > 0.05). Mean PT was 4.1° preoperatively and 5.8° at last follow-up (p > 0.05). Mean SS was 39.2° preoperatively and 41.7° at last follow-up (p > 0.05). 14 patients finished treatment: nine received final fusion and five received rod removal without fusion. Twelve complications occurred: one deep wound infection, six patients developed proximal junctional kyphosis (PJK), one rod fracture, two rods failed to distract, one deformity progressed after rod removal and required spinal fusion, and one patient developed autofusion of the spine prior to end of treatment. CONCLUSION: MCGR treatment is able to control deformity progression. Complication rate was 54.5%. Sagittal balance was not altered and treatment does not seem to have a negative impact on the development of spino-pelvic parameters during growth. Optimal end of treatment for the individual patient still has to be defined.

Minimally invasive lumbopelvic stabilization of sacral fragility fractures in immobilized geriatric patients: feasibility and early return to mobility.

INTRODUCTION: In an aging society, the incidence of sacral fragility fractures is increasing and diagnosis is often delayed. Immobilization has devastating consequences especially in elderly patients. Short-term mobilization of these patients is crucial. The aim of this study is to evaluate the early return to mobility of immobilized geriatric patients with sacral fragility fractures treated with minimally invasive lumbopelvic stabilization. METHODS: Retrospective analysis of thirteen consecutive patients (13 females) which could not be mobilized with conservative treatment, and thus were treated with minimally invasive lumbopelvic stabilization. Pain intensity measurement on an 11-point Numeric Rating Scale (NRS), Tinetti Mobility Test (TMT), and Timed Up and Go Test (TUGT) were performed preoperatively and 4 weeks postoperatively. Surgical and medical complications were analyzed. RESULTS: Mean age at surgery was 83.92 ± 6.27 years and mean ASA score was 2.77 ± 0.42. NRS improved from a mean of 7.18 ± 0.98 preoperatively to a mean of 2.45 ± 0.93 4 weeks postoperatively (Ρ < 0.001). TMT score improved from a mean of 4.15 ± 3.67 preoperatively to a mean of 16.39 ± 4.61 4 weeks postoperatively (Ρ < 0.001). Due to immobilization, patients were not able finish TUGT preoperatively. Four weeks postoperatively TUGT reached a mean of 31.1 ± 11.08 s. There were two surgical complications (one wound healing disorder, one rod dislocation) in two patients that required revision surgery. Two patients developed pneumonia postoperatively. CONCLUSIONS: Minimally invasive lumbopelvic stabilization of sacral fragility fractures is feasible in geriatric patients. Early mobilization of these patients is possible after surgery. The rate of complications is acceptable.

Reliability of Rod Lengthening, Thoracic, and Spino-Pelvic Measurements on Biplanar Stereoradiography in Patients Treated With Magnetically Controlled Growing Rods.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To assess the inter- and intraobserver reliability of thoracic, spino-pelvic, and rod lengthening measurements made on biplanar spinal stereoradiography (EOS imaging) in children treated with magnetically controlled growing rod (MCGR). SUMMARY OF BACKGROUND DATA: MCGR treatment aims to gain spine length while gradually correcting the spinal deformity. Monitoring thoracic and spino-pelvic parameters is crucial for successful management. EOS imaging is widely used for diagnosis and monitoring of children with Early Onset Scoliosis. However, there is a paucity of literature on the reliability of thoracic and spino-pelvic parameters on EOS imaging in children treated with MCGR. METHODS: Three independent reviewers independently read a random assortment of 20 whole spine posteroanterior and lateral radiographs from patients treated with MCGR. The measurements were repeated 4 weeks after the initial read. The following radiological parameters were measured: Cobb angle of the main and compensatory curves, coronal balance, coronal T1-S1 and T1-T12 length, chest width and depth at T6, pelvic inlet width, MCGR distracted lengths, global kyphosis, proximal and distal junctional angle, lordosis, sagittal balance, pelvic incidence, pelvic tilt and sacral slope. Statistical analysis was performed with paired t test and Cronbach alpha for inter- and intraobserver reliability. RESULTS: All measurements had good or excellent intra- and interobserver reliability (α>0.8; P < 0.05), except measurements of the proximal junctional angle which showed only poor intra- and interobserver reliability for patients with an upper instrumented vertebra cranial to T4. CONCLUSION: EOS imaging is reliable for diagnosis and monitoring of children with Early Onset Scoliosis treated with MCGR. EOS imaging is particularly excellent for assessment of MCGR lengthening. Diagnosis and interpretation of early proximal junctional kyphosis within the cervicothoracic junction should be made with caution. LEVEL OF EVIDENCE: 3.

Hybrid Instrumentation in Lumbar Spinal Fusion: A Biomechanical Evaluation of Three Different Instrumentation Techniques.

STUDY DESIGN: Ex vivo human cadaveric study. OBJECTIVE: The development or progression of adjacent segment disease (ASD) after spine stabilization and fusion is a major problem in spine surgery. Apart from optimal balancing of the sagittal profile, dynamic instrumentation is often suggested to prevent or impede ASD. Hybrid instrumentation is used to gain stabilization while allowing motion to avoid hypermobility in the adjacent segment. In this biomechanical study, the effects of two different hybrid instrumentations on human cadaver spines were evaluated and compared with a rigid instrumentation. METHODS: Eighteen human cadaver spines (T11-L5) were subdivided into three groups: rigid, dynamic, and hook comprising six spines each. Clinical parameters and initial mechanical characteristics were consistent among groups. All specimens received rigid fixation from L3-L5 followed by application of a free bending load of extension and flexion. The range of motion (ROM) for every segment was evaluated. For the rigid group, further rigid fixation from L1-L5 was applied. A dynamic Elaspine system (Spinelab AG, Winterthur, Switzerland) was applied from L1 to L3 for the dynamic group, and the hook group was instrumented with additional laminar hooks at L1-L3. ROM was then evaluated again. RESULTS: There was no significant difference in ROM among the three instrumentation techniques. CONCLUSION: Based on this data, the intended advantage of a hybrid or dynamic instrumentation might not be achieved.

Biomechanical Effects of a Dynamic Topping off Instrumentation in a Long Rigid Pedicle Screw Construct.

STUDY DESIGN: Biomechanical ex vivo study. OBJECTIVE: To determine if topping off instrumentation can reduce the hypermobility in the adjacent segments when compared with the classic rigid spinal instrumentation. SUMMARY OF THE BACKGROUND DATA: Long rigid instrumentation might increase the mechanical load in the adjacent segments, the resulting hypermobility, and the risk for adjacent segment disease. Topping off instrumentation intends to reduce the hypermobility at the adjacent level by more evenly distributing segmental motion and, thereby, potentially mitigating adjacent level disease. MATERIALS AND METHODS: Eight human spines (Th12-L5) were divided into 2 groups. In the rigid group, a 3-segment metal rod instrumentation (L2-L5) was performed. The hybrid group included a 2-segment metal rod instrumentation (L3-L5) with a dynamic topping off instrumentation (L2-L3). Each specimen was tested consecutively in 3 different configurations: native (N=8), 2-segment rod instrumentation (L3-L5, N=8), 3-segment instrumentation (rigid: N=4, hybrid: N=4). For each configuration the range of motion (ROM) of the whole spine and each level was measured by a motion capture system during 5 cycles of extension-flexion (angle controlled to ±5 degrees, 0.1 Hz frequency, no preload). RESULTS: In comparison with the intact spine, both the rigid 3-segment instrumentation and the hybrid instrumentation significantly reduced the ROM in the instrumented segments (L2-L5) while increasing the movement in the adjacent segment L1-L2 (P=0.002, η=0.82) and in Th12-L1 (P<0.001, η=0.90). There were no ROM differences between the rigid and hybrid instrumentation in all segments. CONCLUSIONS: Introducing the dynamic topping off did not impart any significant difference in the segmental motion when compared with the rigid instrumentation. Therefore, the current biomechanical study could not show a benefit of using this specific topping off instrumentation to solve the problem of adjacent segment disease.

Paper #11: Reliability of spino-pelvic and thoracic measurements with the EOS in patients with magnetically controlled growing rods in-situ.

This was a reliability assessment of patients who underwent magnetically controlled growing rod (MCGR) treatment with EOS imaging. Most parameters have near perfect reliability except for the sagittal parameters which may limit the ability of investigators to detect complications like proximal junctional kyphosis (PJK).

Radiation-Induced Intraspinal Chondrosarcoma: A Case Report.

Study Design Case report and review of the literature. Objective To report a unique case of an intraspinal chondrosarcoma that was diagnosed 18 years after radiotherapy for a cervical carcinoma and its remarkably unusual clinical presentation. Methods A retrospective case description of an intraspinal mass lesion that occurred 6 weeks after previous spinal surgery. Results Within ∼9 weeks, the tumor had infiltrated the peritoneal cavity and reached the lumbar subcutaneous tissue. Conclusion Radiation-induced sarcomas are rare, are highly aggressive, and may be difficult to diagnose. Furthermore, the only means of achieving long-term survival is through early and extensive surgery.

Quality of life after surgery for neuromuscular scoliosis.

Surgery in patients with neuromuscular scoliosis is associated with a higher rate of complications. It is still controversially discussed whether the patients truly benefit from deformity correction. The purpose of this study is to investigate if the quality of life has been improved and if the patients and their caregivers are satisfied with the results of surgery. This is a retrospective clinical outcome study of 46 patients with neuromuscular scoliosis which were treated with primary stable posterior pedicle screw instrumentation and correction. To achieve fusion only autologous bone was used. Follow up was minimum 2 years and maximum 5 years with an average of 36 months. The patients and/or their caregivers received a questionnaire based on the PEDI (pediatric disability inventory) and the GMFS (gross motor function score). The patients (and their caregivers) were also asked if the quality of life has improved after surgery. Only 32 of 46 patients answered the questionnaire. The answers showed a high approval-rate regarding the patients satisfaction with the surgery and the improvement of quality of life. The questionnaire could be answered from 1 (I do not agree) to 4 (I completely agree). The average agreement to the following statements was: i) the quality of life has improved: 3.35; ii) I am satisfied with surgery: 3.95; iii) the operation has fulfilled my expectations: 3.76. The average age at surgery was 12.7 years. The mean pre-operative cobb-angle of the main curve was 83.1° with a correction post-operatively to a mean of 36.9° and 42.6° at final follow-up. That is an average correction of 56.9%. Although spinal fusion in neuromuscular scoliosis is associated with a higher rate of complications our results show that the patients and their caregivers are satisfied with the operation and the quality of life has improved after surgery.

Spontaneus bilateral pedicle fracture 30 years after Harrington Instrumentation for idiopathic scoliosis: a case report.

INTRODUCTION: Spontaneous fractures of the spine are a common entity. They usually occur in older people with osteoporosis. This case is presented on account of its rarity. To the best of the authors' knowledge only one case of an osteoporotic pedicle fracture after Harrington Instrumentation has been described before. CASE PRESENTATION: We report the case of a 46-year-old Caucasian woman who underwent surgery due to idiopathic scoliosis with a Harrington Instrumentation (T4 to L3) 30 years ago. During the operation she was infected with hepatitis C while receiving erythrocyte concentrates and has suffered from liver cirrhosis since then. She presented with a sudden pain in her lower back and paraesthesia in both her legs but no other neurological symptoms. A computed tomography scan showed a bilateral pedicle fracture of L3 and an additional compression fracture of L4. In the first session we performed a dorsal stabilization with massive intraoperative bleeding and a postoperative failure of liver synthesis. In a second session an additional ventral augmentation was done. After the second operation she developed a hepatorenal syndrome. Both operations left the patient in a very critical state which led to a prolonged stay in the intensive care and rehabilitation unit. At her 12-month follow-up visit, she was free of complaints. CONCLUSION: The un-physiological load of the spine after Harrington Instrumentation can lead to osteoporosis due to inactivity even in younger patients. Although these implants are not used anymore one should keep this possibility in mind when dealing with patients who have received Harrington rods in surgical procedures.