The potential of spring distraction to dynamically correct complex spinal deformities in the growing child

Purpose: Current treatment of progressive early onset scoliosis involves growth-friendly instrumentation if conservative treatment fails. These implants guide growth by passive sliding or repeated lengthenings. None of these techniques provide dynamic correction after implantation. We developed the spring distraction system (SDS), by using one or multiple compressed springs positioned around a standard sliding rod, to provide active continuous distraction of the spine to stimulate growth and further correction. The purpose of this study was to determine feasibility and proof of concept of the SDS. Methods: We developed a versatile, dynamic spring distraction system for patients who would benefit from active continuous distraction. This prospective case series evaluates four patients with exceptional and progressive congenital spine deformities. Results: Four patients had a mean age of 6.8 years at surgery with a mean follow-up of 36 months (range 25–45). The mean progressive thoracic lordosis, which was the reason for initiating surgical treatment in two patients, changed from 32° lordosis preoperatively to 1° kyphosis post-operatively. During follow-up, this further improved to 32° thoracic kyphosis. In the two other patients, with cervicothorcacic scoliosis, the main coronal curve improved from 79° pre-operatively to 56° post-operatively and further improved to 42°. The mean T1-S1 spine growth during follow-up for all patients was 1.3 cm/year. There was one reoperation because of skin problems and no device-failures. Conclusion: These early results show the feasibility and the proof of concept of spring-based distraction as a dynamic growth-enhancing system with the potential of further correction of the deformity after implantation

Induction of a representative idiopathic-like scoliosis in a porcine model using a multidirectional dynamic spring-based system

BACKGROUND CONTEXT: Scoliosis is a 3D deformity of the spine in which vertebral rotation plays an important role. However, no treatment strategy currently exists that primarily applies a continuous rotational moment over a long period of time to the spine, while preserving its mobility. We developed a dynamic, torsional device that can be inserted with standard posterior instrumentation. The feasibility of this implant to rotate the spine and preserve motion was tested in growing mini-pigs. PURPOSE: To test the quality and feasibility of the torsional device to induce the typical axial rotation of scoliosis while maintaining growth and mobility of the spine. STUDY DESIGN: Preclinical animal study with 14 male, 7 month old Gottingen mini-pigs. Comparison of two scoliosis induction methods, with and without the torsional device, with respect to 3D deformity and maintenance of the scoliosis after removal of the implants. METHODS: Fourteen mini-pigs received either a unilateral tether-only (n=6) or a tether combined with a contralateral torsional device (n=8). X-rays and CT-scans were made post-operative, at 8 weeks and at 12 weeks. Flexibility of the spine was assessed at 12 weeks. In 3 mini-pigs per condition, the implants were removed and the animals were followed until no further correction was expected. RESULTS: At 12 weeks the tether-only group yielded a coronal Cobb angle of 16.8±3.3°For the tether combined with the torsional device this was 22.0±4.0°. The most prominent difference at 12 weeks was the axial rotation with 3.6±2.8° for the tether-only group compared to 18.1±4.6° for the tether-torsion group. Spinal growth and flexibility remained normal and comparable for both groups. After removal of the devices, the induced scoliosis reduced by 41% in both groups. There were no adverse tissue reactions, implant complications or infections. CONCLUSION: The present study indicates the ability of the torsional device combined with a tether to induce a flexible idiopathic-like scoliosis in mini-pigs. The torsional device was necessary to induce the typical axial rotation found in human scoliosis. Clinical significance: The investigated torsional device could induce apical rotation in a flexible and growing spine. Whether this may be used to reduce a scoliotic deformity remains to be investigated

Three-dimensional correction of scoliosis by a double spring reduction system as a dynamic internal brace:a pre-clinical study in Göttingen minipigs

BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) is a major skeletal deformity that is characterized by a combination of apical rotation, lateral bending and apical lordosis. To provide full 3D correction, all these deformations should be addressed. We developed the Double Spring Reduction (DSR) system, a (growth-friendly) concept that continuously corrects the deformity through two different elements: A posterior convex Torsional Spring Implant (TSI) that provides a derotational torque at the apex, and a concave Spring Distraction System (SDS), which provides posterior, concave distraction to restore thoracic kyphosis. PURPOSE: To determine whether the DSR components are able to correct an induced idiopathic-like scoliosis and to compare correction realized by the TSI alone to correction enforced by the complete DSR implant. STUDY DESIGN/SETTING: Preclinical randomized animal cohort study. PATIENT SAMPLE: Twelve growing Göttingen minipigs. OUTCOME MEASURES: Coronal Cobb angle, T10-L3 lordosis/kyphosis, apical axial rotation, relative anterior lengthening. METHODS: All mini-pigs received the TSI with a contralateral tether to induce an idiopathic-like scoliosis with apical rotation (mean Cobb: 20.4°; mean axial apical rotation: 13.1°, mean lordosis: 4.9°). After induction, the animals were divided into two groups: One group (N=6) was corrected by TSI only (TSI only-group), another group (N=6) was corrected by a combination of TSI and SDS (DSR-group). 3D spinal morphology on CT was compared between groups over time. After 2 months of correction, animals were euthanized. RESULTS: Both intervention groups showed excellent apical derotation (TSI only-group: 15.0° to 5.4°; DSR-group: 11.2° to 3.5°). The TSI only-group showed coronal Cobb improvement from 22.5° to 6.0°, while the DSR-group overcorrected the 18.3° Cobb to -9.2°. Lordosis was converted to kyphosis in both groups (TSI only-group: -4.6° to 4.3°; DSR-group: -5.2° to 25.0°) which was significantly larger in the DSR-group (p<.001). CONCLUSIONS: The TSI alone realized strong apical derotation and moderate correction in the coronal and sagittal plane. The addition of distraction on the posterior concavity resulted in more coronal correction and reversal of induced lordosis into physiological kyphosis. CLINICAL SIGNIFICANCE: This study shows that dynamic spring forces could be a viable method to guide the spine towards healthy alignment, without fusing it or inhibiting its growth

Data for: The efficacy of intrawound vancomycin powder and povidone-iodine irrigation to prevent Surgical Site Infections in complex instrumented spine surgery

Data regarding surgical site infections in instrumented spinal surgery in a specialized spine surgery hospital. Additional data regarding spinal surgical site infections can be obtained by contacting the corresponding author

Data for: The efficacy of intrawound vancomycin powder and povidone-iodine irrigation to prevent Surgical Site Infections in complex instrumented spine surgery

Data regarding surgical site infections in instrumented spinal surgery in a specialized spine surgery hospital. Additional data regarding spinal surgical site infections can be obtained by contacting the corresponding author.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

The impairment test of goodwill: an empirical analysis of incentives for earnings management in Italian publicly traded companies

Since the current International Accounting Standard 36 introduced substantial subjectivity while testing goodwill for impairment, this study aims to establish if management exploits the discretion and performs the impairment test of goodwill opportunistically. The presence of discretion, while applying impairment test, is tested on the sample of Italian publicly traded companies in the period of the current financial crisis. Despite the fact that the sample of companies consists of those with market to book ratio less than one, only 26% of the companies recorded a goodwill write-off. The logistic regression was used to test contracting and reporting incentives. The results of the analysis indicate that even in the case of IFRS users some incentives exist, while recognising the impairment losses of goodwill

Three-dimensional correction of scoliosis by a double spring reduction system as a dynamic internal brace: a pre-clinical study in Göttingen minipigs

BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) is a major skeletal deformity that is characterized by a combination of apical rotation, lateral bending and apical lordosis. To provide full 3D correction, all these deformations should be addressed. We developed the Double Spring Reduction (DSR) system, a (growth-friendly) concept that continuously corrects the deformity through two different elements: A posterior convex Torsional Spring Implant (TSI) that provides a derotational torque at the apex, and a concave Spring Distraction System (SDS), which provides posterior, concave distraction to restore thoracic kyphosis. PURPOSE: To determine whether the DSR components are able to correct an induced idiopathic-like scoliosis and to compare correction realized by the TSI alone to correction enforced by the complete DSR implant. STUDY DESIGN/SETTING: Preclinical randomized animal cohort study. PATIENT SAMPLE: Twelve growing Göttingen minipigs. OUTCOME MEASURES: Coronal Cobb angle, T10-L3 lordosis/kyphosis, apical axial rotation, relative anterior lengthening. METHODS: All mini-pigs received the TSI with a contralateral tether to induce an idiopathic-like scoliosis with apical rotation (mean Cobb: 20.4°; mean axial apical rotation: 13.1°, mean lordosis: 4.9°). After induction, the animals were divided into two groups: One group (N=6) was corrected by TSI only (TSI only-group), another group (N=6) was corrected by a combination of TSI and SDS (DSR-group). 3D spinal morphology on CT was compared between groups over time. After 2 months of correction, animals were euthanized. RESULTS: Both intervention groups showed excellent apical derotation (TSI only-group: 15.0° to 5.4°; DSR-group: 11.2° to 3.5°). The TSI only-group showed coronal Cobb improvement from 22.5° to 6.0°, while the DSR-group overcorrected the 18.3° Cobb to -9.2°. Lordosis was converted to kyphosis in both groups (TSI only-group: -4.6° to 4.3°; DSR-group: -5.2° to 25.0°) which was significantly larger in the DSR-group (p<.001). CONCLUSIONS: The TSI alone realized strong apical derotation and moderate correction in the coronal and sagittal plane. The addition of distraction on the posterior concavity resulted in more coronal correction and reversal of induced lordosis into physiological kyphosis. CLINICAL SIGNIFICANCE: This study shows that dynamic spring forces could be a viable method to guide the spine towards healthy alignment, without fusing it or inhibiting its growth

High diagnostic accuracy of white blood cell scintigraphy for fracture related infections : Results of a large retrospective single-center study

Introduction: White blood cell (WBC) scintigraphy for diagnosing fracture-related infections (FRIs) has only been investigated in small patient series. Aims of this study were (1) to establish the accuracy of WBC scintigraphy for diagnosing FRIs, and (2) to investigate whether the duration of the time interval between surgery and WBC scintigraphy influences its accuracy. Patients and methods: 192 consecutive WBC scintigraphies with 99mTc-HMPAO-labelled autologous leucocytes performed for suspected peripheral FRI were included. The golden standard was based on the outcome of microbiological investigation in case of surgery, or − when these were not available – on clinical follow-up of at least six months. The discriminative ability of the imaging modalities was quantified by several measures of diagnostic accuracy. A multivariable logistic regression analysis was performed to identify predictive variables of a false-positive or false-negative WBC scintigraphy test result. Results: WBC scintigraphy had a sensitivity of 0.79, a specificity of 0.97, a positive predicting value of 0.91, a negative predicting value of 0.93 and a diagnostic accuracy of 0.92 for detecting an FRI in the peripheral skeleton. The duration of the interval between surgery and the WBC scintigraphy did not influence its diagnostic accuracy; neither did concomitant use of antibiotics or NSAIDs. There were 11 patients with a false-negative (FN) WBC scintigraphy, the majority of these patients (n = 9, 82%) suffered from an infected nonunion. Four patients had a false-positive (FP) WBC scintigraphy. Conclusions: WBC scintigraphy showed a high diagnostic accuracy (0.92) for detecting FRIs in the peripheral skeleton. Duration of the time interval between surgery for the initial injury and the WBC did not influence the results which indicate that WBC scintigraphy is accurate shortly after surgery