Bupivacaine pleural effusion mimicking a hemothorax after a thoracoscopic microdiscectomy with epidural anesthesia.

PURPOSE: Post-operative pain after video-assisted thoracoscopic surgery is often treated using thoracic epidural analgesics or thoracic paravertebral analgesics. This article describes a case where a thoracic disc herniation is treated with a thoracoscopic microdiscectomy with post-operative thoracic epidural analgesics. The patient developed a bupivacaine pleural effusion which mimicked a hemothorax on computed tomography (CT). METHODS: The presence of bupivacaine in the pleural effusion was confirmed using a high performance liquid chromatography method. RESULTS: The patient underwent a re-exploration to relieve the pleural effusion. The patient showed a long-term recovery similar to what can be expected from an uncomplicated thoracoscopic microdiscectomy. CONCLUSION: A pleural effusion may occur when thoracic epidural analgesics are used in patents with a corridor between the pleural cavity and epidural space.

The Mechanism of Volume Regulation by Cervical Neuroforaminal Veins as was Previously Demonstrated for the Internal Vertebral Venous Plexus (IVVP) in the Cervical and Lumbar Region / Mecanismo de Regulación del Volumen por las Venas Neuroforaminales Cervicales como se Demostró Previamente para el Plexo Venoso Vertebral Interno (PVVI) en la Regiones Cervical y Lumbar

SUMMARY: Head and cervical spine movements cause narrowing or widening of neuroforamina. In healthy individuals these movements do not cause symptoms of radiculopathy. This implies a compensating volume-regulating mechanism of the neuroforamina. Such a mechanism has been postulated in the years before CT and MRI for the neuroforaminal veins. Dural sac indentations with emptying and refilling of the internal vertebral venous plexus (IVVP) were postulated in the lumbar region using myelography. Emptying of the IVVP occurs in the lumbar spine when moving towards maximal extension and refilling while moving towards maximal flexion. Such indentations have not been shown in the cervical region. With MRI this mechanism has been demonstrated during axial rotation in the C1-C2 segment. It consists of emptying and refilling of the IVVP and thus prevents dural sac compression. During spinal surgery, the IVVP and connecting neuroforaminal veins may be damaged. Because the clinical implications of dysfunction of this protecting mechanism of the IVVP and its neuroforaminal venous connections are not clear, the consequences of such damage are unknown. Therefore, these venous structures should be examined by studying the cervical spine in supine position and, if possible, in different postures (flexion, extension and axial rotation) using MRI with contrast-enhancement and fat suppression. These images may be a basis for future advancement of clinical care.

Los movimientos de la cabeza y la columna cervical provocan un estrechamiento o ensanchamiento de las neuroforaminas. En individuos sanos estos movimientos no causan síntomas de radiculopatía. Esto implica un mecanismo compensador de regulación del volumen de las neuroforaminas. Este mecanismo se ha postulado en los años anteriores a la TC y la RM para las venas neuroforaminales. Mediante mielografía se postularon hendiduras del saco dural con vaciado y llenado del plexo venoso vertebral interno (PVVI) en la región lumbar. El vaciado del PVVI se produce en la columna lumbar cuando se mueve hacia la máxima extensión y se rellena mientras se mueve hacia la máxima flexión. En la región cervical no se han observado tales depresiones. Con resonancia magnética se ha demostrado este mecanismo durante la rotación axial en el segmento C1-C2. Consiste en vaciar y rellenar la PVVI y así evitar la compresión del saco dural. Durante la cirugía de columna, la PVVI y las venas neuroforaminales que las conectan pueden dañarse. Debido a que las implicaciones clínicas de la disfunción de este mecanismo protector de la PVVI y sus conexiones venosas neuroforaminales no están claras, se desconocen las consecuencias de dicho daño. Por tanto, estas estructuras venosas deben examinarse estudiando la columna cervical en decúbito supino y, si es posible, en diferentes posturas (flexión, extensión y rotación axial) mediante resonancia magnética con contraste y supresión grasa. Estas imágenes pueden ser una base para futuros avances de la atención clínica.

An observational study of quality of motion in the aging cervical spine: sequence of segmental contributions in dynamic fluoroscopy recordings.

BACKGROUND: The term 'physiological motion of the spine' is commonly used although no proper definition exists. Previous work has revealed a consistent sequence of cervical segmental contributions in 80-90% of young healthy individuals. Age has been shown to be associated with a decreased quantity of motion. Therefore, it is of interest to study whether this sequence persists throughout aging. The aim of this prospective cohort study is to investigate if the consistent sequence of cervical segmental contributions in young asymptomatic individuals remains present in elderly asymptomatic individuals. METHODS: In this prospective cohort study, dynamic flexion to extension cinematographic recordings of the cervical spine were made in asymptomatic individuals aged 55-70 years old. Individuals without neck pain and without severe degenerative changes were included. Two recordings were made in each individual with a 2-to-4-week interval (T1 and T2). Segmental rotation of each individual segment between C4 and C7 was calculated to determine the sequence of segmental contributions. Secondary outcomes were segmental range of motion (sRoM) and sagittal alignment. RESULTS: Ten individuals, with an average age of 61 years, were included. The predefined consistent sequence of segmental contributions was found in 10% of the individuals at T1 and 0% at T2. sRoM and total range of motion (tRoM) were low in all participants. There was no statistically significant correlation between sagittal alignment, degeneration and sRoM in the respective segments, nor between cervical lordosis and tRoM. CONCLUSIONS: This study shows that aging is associated with loss of the consistent motion pattern that was observed in young asymptomatic individuals. The altered contribution of the cervical segments during extension did not appear to be correlated to the degree of degeneration or sagittal alignment. Trial registration clinicaltrials.gov NCT04222777, registered 10.01.2020.

A randomized controlled trial with extended long-term follow-up: Quality of cervical spine motion after anterior cervical discectomy (ACD) or anterior cervical discectomy with arthroplasty (ACDA).

Introduction: In previous research, a consistent sequence of segmental contributions during dynamic extension X-rays of the cervical spine was observed in 80-90% of healthy participants. Research question: To investigate whether this previously defined 'normal' sequence of segmental contributions was present in patients who underwent anterior cervical discectomy with arthroplasty (ACDA) or anterior cervical discectomy (ACD). Materials & methods: A randomized controlled trial with extended follow-up was conducted. Patients with single level cervical degenerative radiculopathy with a surgical indication were included and randomized. Dynamic X-ray recordings were made before surgery, one-year post-operative, and at long term follow-up. Results: A total of 27 patients were included, three in an ACDA pilot group and 24 were randomized to receive ACDA (N = 12) or ACD (N = 12). A total of 20 patients were available for follow-up. Preoperatively, 16.7% of patients in the ACDA group and 58.3% of patients in the ACD group showed a normal sequence. One-year post-operative, 66.7% showed a normal sequence in the ACDA group versus 30.0% in the ACD group (p = 0.036). After an average of 11-years follow-up, a normal sequence was observed in 9.1% of patients in the ACDA group and in none of the patients in the ACD group (p = 0.588). Discussion & conclusion: These findings suggest that while ACDA can restore and preserve a normal sequence of segmental contributions in the short term, this effect is not maintained in the long term. Throughout the process of ageing, not only the quantity, but also the quality of motion changes.

Mother and daughter with a SMARCE1 mutation resulting in a cervical clear cell meningioma at an identical location: illustrative cases.

BACKGROUND: A rare meningioma subtype is a clear cell (CC) meningioma, which can be associated with a SMARCE1 gene mutation. Manifestation of a CC meningioma in the cervical spine is unusual. In the current case, both mother and daughter present with a CC meningioma at an identical cervical location. OBSERVATIONS: A 67-year-old patient with an intradural extramedullary mass at the level of C5 presented with progressive myelopathy. The mass was resected through a ventral approach by a two-level corpectomy with an expandable cage and instrumentation. The daughter of this patient appeared to have had an intradural extramedullary mass at C5 at the age of 20, which was resected through a posterior approach. Pathological investigation of both tumors revealed CC meningioma. Genetic testing of the daughter revealed a SMARCE1 mutation. LESSONS: It is of major importance to consider a SMARCE1 mutation in elderly presenting with a CC meningioma, which is still uncommon in current practice. This could lead to timely diagnostics in the succeeding generation. Complete resection of a CC meningioma is important because of the high recurrence rate. Routine follow-up should therefore be performed in the postoperative period. An anterior approach should be considered for a ventral cervical CC meningioma.

The Variability of Lumbar Sequential Motion Patterns: Observational Study.

BACKGROUND: Physiological motion of the lumbar spine is a topic of interest for musculoskeletal health care professionals since abnormal motion is believed to be related to lumbar complaints. Many researchers have described ranges of motion for the lumbar spine, but only few have mentioned specific motion patterns of each individual segment during flexion and extension, mostly comprising the sequence of segmental initiation in sagittal rotation. However, an adequate definition of physiological motion is still lacking. For the lower cervical spine, a consistent pattern of segmental contributions in a flexion-extension movement in young healthy individuals was described, resulting in a definition of physiological motion of the cervical spine. OBJECTIVE: This study aimed to define the lumbar spines' physiological motion pattern by determining the sequence of segmental contribution in sagittal rotation of each vertebra during maximum flexion and extension in healthy male participants. METHODS: Cinematographic recordings were performed twice in 11 healthy male participants, aged 18-25 years, without a history of spine problems, with a 2-week interval (time point T1 and T2). Image recognition software was used to identify specific patterns in the sequence of segmental contributions per individual by plotting segmental rotation of each individual segment against the cumulative rotation of segments L1 to S1. Intraindividual variability was determined by testing T1 against T2. Intraclass correlation coefficients were tested by reevaluation of 30 intervertebral sequences by a second researcher. RESULTS: No consistent pattern was found when studying the graphs of the cinematographic recordings during flexion. A much more consistent pattern was found during extension, especially in the last phase. It consisted of a peak in rotation in L3L4, followed by a peak in L2L3, and finally, in L1L2. This pattern was present in 71% (15/21) of all recordings; 64% (7/11) of the participants had a consistent pattern at both time points. Sequence of segmental contribution was less consistent in the lumbar spine than the cervical spine, possibly caused by differences in facet orientation, intervertebral discs, overprojection of the pelvis, and muscle recruitment. CONCLUSIONS: In 64% (7/11) of the recordings, a consistent motion pattern was found in the upper lumbar spine during the last phase of extension in asymptomatic young male participants. Physiological motion of the lumbar spine is a broad concept, influenced by multiple factors, which cannot be captured in a firm definition yet. TRIAL REGISTRATION: ClinicalTrials.gov NCT03737227; https://clinicaltrials.gov/ct2/show/NCT03737227. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/14741.

Clinical adjacent segment pathology after anterior cervical discectomy, with and without fusion, for cervical degenerative disc disease: A single center retrospective cohort study with long-term follow-up.

Introduction: Clinical adjacent segment pathology (CASP) continues to be a cause of concern after anterior surgical treatment for single- or multilevel cervical degenerative disc disease (CDDD). The current literature reports inconsistent incidence rates and contended risk factors in the development of CASP. Research question: The aim is to determine the incidence of additional CASP-related surgeries after anterior cervical discectomy with fusion (ACDF) or without fusion (ACD) for CDDD. Secondary outcomes include risk factors for the development of CASP and long-term clinical outcomes. Materials & methods: This is a single-center, retrospective cohort study with a long-term follow up. Patients undergoing ACD(F) for CDDD between January 2012 and December 2019 were included. Results: A total of 601 patients were included, with an average follow-up period of 5.0 years. Most patients underwent ACDF with stand-alone cages (87.7%). CASP developed in 58 (9.7%) patients, 41 (70.7%) of which required additional adjacent level surgery. ACD significantly accelerated the development of CASP. The C2-C7 Cobb angle appeared less lordotic upon early post-operative imaging in ACDF patients that later-on developed CASP. Baseline degeneration at the index level and adjacent levels was not significantly different between patients with and without CASP. Discussion & conclusion: In this retrospective cohort, we observe a relatively low rate of additional surgery for CASP in ACDF with stand-alone cages. We suggest that surgical technique, fusion, segmental kyphosis and natural degeneration play a multifactorial role in the development of CASP. Complication rates were low and clinical outcomes were similar for all techniques used.

Research protocol: Cervical Arthroplasty Cost Effectiveness Study (CACES): economic evaluation of anterior cervical discectomy with arthroplasty (ACDA) versus anterior cervical discectomy with fusion (ACDF) in the surgical treatment of cervical degenerative disc disease - a randomized controlled trial.

INTRODUCTION: To date, there is no consensus on which anterior surgical technique is more cost-effective in treating cervical degenerative disc disease (CDDD). The most commonly used surgical treatment for patients with single- or multi-level symptomatic CDDD is anterior cervical discectomy with fusion (ACDF). However, new complaints of radiculopathy and/or myelopathy commonly develop at adjacent levels, also known as clinical adjacent segment pathology (CASP). The extent to which kinematics, surgery-induced fusion, natural history, and progression of disease play a role in the development of CASP remains unclear. Anterior cervical discectomy with arthroplasty (ACDA) is another treatment option that is thought to reduce the incidence of CASP by preserving motion in the operated segment. While ACDA is often discouraged, as the implant costs are higher while the clinical outcomes are similar to ACDF, preventing CASP might be a reason for ACDA to be a more cost-effective technique in the long term. METHODS AND ANALYSIS: In this randomized controlled trial, patients will be randomized to receive ACDF or ACDA in a 1:1 ratio. Adult patients with single- or multi-level CDDD and symptoms of radiculopathy and/or myelopathy will be included. The primary outcome is cost-effectiveness and cost-utility of both techniques from a healthcare and societal perspective. Secondary objectives are the differences in clinical and radiological outcomes between the two techniques, as well as the qualitative process surrounding anterior decompression surgery. All outcomes will be measured at baseline and every 6 months until 4 years post-surgery. DISCUSSION: High-quality evidence regarding the cost-effectiveness of both ACDA and ACDF is lacking; to date, there are no prospective trials from a societal perspective. Considering the aging of the population and the rising healthcare costs, there is an urgent need for a solid clinical cost-effectiveness trial addressing this question. TRIAL REGISTRATION: ClinicalTrials.gov NCT04623593. Registered on 29 September 2020.

A Systematic Review on Neurological Outcomes for Cervical Degenerative Myelopathy After Anterior Decompression Surgery: Motion Preservation vs Fusion.

BACKGROUND: Although it is well established that surgically treated patients with cervical degenerative myelopathy (CDM) improve irrespective of the anterior decompression technique used, no consensus exists on what technique is superior in terms of neurological recovery. A general concern exists that anterior cervical discectomy with arthroplasty (ACDA) leads to less favorable outcomes in CDM due to microtrauma caused by preserved mobility. It is remarkable that current literature mainly uses pain scores to assess clinical outcomes after anterior decompression surgery, especially considering that pain may not be the most relevant outcome for CDM. This systematic review evaluated the literature concerning neurological outcomes in patients with CDM treated with anterior decompression surgery and assessed by validated myelopathy scores. METHODS: Systematic searches were carried out in PubMed, EMBASE, Web of Science, CINAHL, and the Cochrane Library. Prospective studies were included when patients with isolated CDM were treated with anterior decompression surgery, and a validated myelopathy outcome score was used. RESULTS: A total of 11 studies were included from the 16,032 identified studies. All studies used the modified Japanese Orthopedic Association (JOA) outcome score and showed improvement for all anterior techniques. The mean improvement in anterior cervical discectomy and fusion (ACDF) was 4.80 and 3.64 for the modified JOA and JOA outcome scores, respectively. The JOA for ACDA showed a mean improvement of 5.51. The overall quality of the included articles was low to moderate according to the Cochrane tool. CONCLUSION: Neurological recovery of CDM is similar after all anterior decompression techniques, including ACDA when compared with ACDF. CLINICAL RELEVANCE: The current literature gives no reason to dissuade the use of ACDA in cervical myelopathy.

Isolated cognitive dysfunction in the presence of superficial siderosis after meningioma resection at the cervicothoracic junction.

Superficial siderosis is a rare disorder characterised by the deposition of haemosiderin on the surface of the central nervous system. Cognitive dysfunction has sporadically been reported in relation with superficial siderosis. We present a 61-year-old man with cognitive dysfunction in the presence of the typical radiological image of temporal and cerebellar superficial siderosis, most likely due to pseudomeningocoele 14 years after resection of a meningioma at the cervicothoracic junction. Xantochromia was present on cerebrospinal fluid investigation and a source of bleeding was seen during surgical exploration. Despite surgical treatment of the suspected bleeding source, the patient deteriorated and neuropsychological examination 1 year after surgery showed progression of cognitive dysfunction to dementia. It is likely that in the absence of other typical symptoms such as cerebellar ataxia and hearing loss, the cognitive dysfunction was not related to the superficial siderosis.

Lumbar Intervertebral Motion Analysis During Flexion and Extension Cinematographic Recordings in Healthy Male Participants: Protocol.

BACKGROUND: Physiological motion of the lumbar spine is a subject of interest for musculoskeletal health care professionals, as abnormal motion is believed to be related to lumbar conditions and complaints. Many researchers have described ranges of motion for the lumbar spine, but only a few have mentioned specific motion patterns of each individual segment during flexion and extension. These motion patterns mostly comprise the sequence of segmental initiation in sagittal rotation. However, an adequate definition of physiological motion of the lumbar spine is still lacking. The reason for this is the reporting of different ranges of motion and sequences of segmental initiation in previous studies. Furthermore, due to insufficient fields of view, none of these papers have reported on maximum flexion and extension motion patterns of L1 to S1. In the lower cervical spine, a consistent pattern of segmental contributions was recently described. In order to understand physiological motion of the lumbar spine, it is necessary to systematically study motion patterns, including the sequence of segmental contribution, of vertebrae L1 to S1 in healthy individuals during maximum flexion and extension. OBJECTIVE: This study aims to define the lumbar spines' physiological motion pattern of vertebrae L1, L2, L3, L4, L5, and S1 by determining the sequence of segmental contribution and the sequence of segmental initiation of motion in sagittal rotation of each vertebra during maximum flexion and extension. The secondary endpoint will be exploring the possibility of analyzing the intervertebral horizontal and vertical translation of each vertebra during maximum flexion and extension. METHODS: Cinematographic recordings will be performed in 11 healthy male participants, aged 18-25 years, without a history of spine problems. Cinematographic flexion and extension recordings will be made at two time points with a minimum 2-week interval in between. RESULTS: The study has been approved by the local institutional medical ethical committee (Medical Research Ethics Committee of Zuyderland and Zuyd University of applied sciences) on September 24, 2018. Inclusion of participants will be completed in 2020. CONCLUSIONS: If successful, these physiological motion patterns can be compared with motion patterns of patients with lumbar conditions before or after surgery. Ultimately, researchers may be able to determine differences in biomechanics that can potentially be linked to physical complaints like low back pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT03737227; https://clinicaltrials.gov/ct2/show/NCT03737227. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/14741.

Two-Nation Comparison of Classification and Treatment of Subaxial Cervical Spine Fractures: An Internet-Based Multicenter Study Among Spine Surgeons.

BACKGROUND: To date, no evidence-based treatment algorithm is available for fractures of the subaxial spine. The aim of the present study was to assess and compare the management strategy for traumatic subaxial fractures among German and Dutch spine surgeons. METHODS: In our web-based multicenter study, German and Dutch spine surgeons evaluated the computed tomography data of traumatic subaxial fractures (C3-C7). Supplementary case-specific information was provided. The fractures were classified using the AO spine classification. Next, 9 questions concerning the treatment algorithm were evaluated. Data were analyzed using SPSS. Statistical significance was defined as P < 0.05. RESULTS: Ten surgeons (5/country) evaluated 31 cases (310 votes). The fractures were classified as AO type A in 37% (114 votes), type B in 50% (155 votes), and type C in 13% (41 votes). German spine surgeons had a lower threshold concerning the indication for surgical treatment (German, 94.2% vs. Netherlands, 58.1%; P < 0.05). A consensus was present for operative stabilization for type B and C injuries, but a discrepancy was found in the therapeutic algorithm for type A fractures. The most significant difference was seen in the treatment of type A2 and A3 fractures (surgery for type A2/A3 fracture: German, 92.9% vs. Netherlands, 5.3%; P < 0.05). CONCLUSION: We found a consensus for the stabilization of AO type B and C fractures but country-specific differences in the treatment of type A fractures, especially for A2 and A3 fractures. Further evidence is necessary to ensure more consistent international treatment strategies.

Radiographic Axial Malalignment is Associated With Pretreatment Patient-Reported Health-Related Quality of Life Measures in Adult Degenerative Scoliosis: Implementation of a Novel Radiographic Software Tool.

STUDY DESIGN: Retrospective study of prospectively collected data. OBJECTIVES: The purpose of this study was to evaluate the relationship between apical vertebral axial rotation and pretreatment patient-reported health-related quality of life (HRQOL), disability, and pain in patients with adult degenerative scoliosis (ADS) using a novel radiographic software tool. SUMMARY OF BACKGROUND DATA: Recent studies have demonstrated that in ADS, sagittal and coronal plane deformity are weakly to moderately associated with HRQOL, disability, and pain. However, as ADS is a three-dimensional spinal deformity, the impact of axial malalignment on HRQOL is yet to be determined. METHODS: A total of 74 ADS patients were enrolled. HRQOL measures included the Short Form-36v2 (SF-36v2) and Scoliosis Research Society questionnaire (SRS-22r). Disability and pain measures included the Oswestry Disability Index (ODI) and numeric rating scale back and leg pain. Radiographic measures included Cobb angle (CA), sagittal spinopelvic parameters, lateral and anteroposterior (AP) translation of the apical vertebra. The amount of apical vertebral axial rotation was measured on digital AP radiograph images using a novel software technology. Subjects were stratified into four clinical groups based on the degree of apical vertebral axial rotation. RESULTS: Apical vertebral axial rotation showed no association with lateral (r = 0.21; p = .15) and AP (r = 0.08, p = .80) translation of the apical vertebra. A significant moderate association was found between apical vertebral axial rotation and Cobb angle (r = 0.57; p < .05). Patients in the group with the highest degree of apical vertebral axial rotation reported significantly worse ODI and SRS-22r Subtotal and Pain scores (p < .05), irrespective of sagittal spinopelvic parameters. CONCLUSIONS: This is the first study that reports on the association between apical vertebral axial rotation and pretreatment HRQOL, disability, and pain in ADS. This study suggests that increased apical vertebral axial rotation is associated with suboptimal pretreatment health status scores. LEVEL OF EVIDENCE: Level III.

Pilot Study of Sequence of Segmental Contributions in the Lower Cervical Spine During Active Extension and Flexion: Healthy Controls Versus Cervical Degenerative Disc Disease Patients.

STUDY DESIGN: A retrospective study in which, first, a definition of normal movement in the cervical spine is formulated. Second, use of this definition in differentiating between normal and abnormal movement of the cervical spine is evaluated. OBJECTIVE: To formulate a clear definition of the normal sequence of segmental contributions in the cervical spine during flexion/extension, and to evaluate the sensitivity, specificity, and reliability of sequence of segmental contributions analysis in differentiating between normal and abnormal movement of the cervical spine in healthy controls and patients with cervical degenerative disc disease (CDDD). SUMMARY OF BACKGROUND DATA: To study mobility before and after cervical arthroplasty, segmental range of motion (sROM) is most commonly used. Analysis of sequence of segmental contributions during flexion and/or extension might be more suitable. METHODS: The definition was formulated by analyzing flexion cinematographic recordings (FCRs) and extension cinematographic recordings (ECRs) in healthy controls. Sequences in ECRs were more consistent than in FCRs and were therefore used to define "normal" motion. Five blinded spine surgeons scored randomized graphs from ECRs in 20 healthy controls and 10 preoperative CDDD patients, using this definition, at three time points. Sensitivity, specificity, and reliability were calculated. RESULTS: Reliability of scoring as normal or abnormal is high (Fleiss kappa of 0.80-0.84, 95% confidence interval, CI: 0.66-0.98), sensitivity and specificity are also high, with an average sensitivity of 90% (95% CI: 78.4-99.8%), and an average specificity of 85% (95% CI: 72.9-96.4%). CONCLUSION: This is the first described method that can reliably differentiate between normal or abnormal movement of the cervical spine in an individual subject. This enables an observer to determine if the normal sequence is restored after arthroplasty. In contrast to the given method, sROMs are not able to distinguish between healthy controls and CDDD patients. LEVEL OF EVIDENCE: 2.

Development and assessment of a digital X-ray software tool to determine vertebral rotation in adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: The amount of vertebral rotation in the axial plane is of key importance in the prognosis and treatment of adolescent idiopathic scoliosis (AIS). Current methods to determine vertebral rotation are either designed for use in analogue plain radiographs and not useful in digital images, or lack measurement precision and are therefore less suitable for the follow-up of rotation in AIS patients. PURPOSE: This study aimed to develop a digital X-ray software tool with high measurement precision to determine vertebral rotation in AIS, and to assess its (concurrent) validity and reliability. STUDY DESIGN/SETTING: In this study a combination of basic science and reliability methodology applied in both laboratory and clinical settings was used. METHODS: Software was developed using the algorithm of the Perdriolle torsion meter for analogue AP plain radiographs of the spine. Software was then assessed for (1) concurrent validity and (2) intra- and interobserver reliability. Plain radiographs of both human cadaver vertebrae and outpatient AIS patients were used. Concurrent validity was measured by two independent observers, both experienced in the assessment of plain radiographs. Reliability-measurements were performed by three independent spine surgeons. RESULTS: Pearson correlation of the software compared with the analogue Perdriolle torsion meter for mid-thoracic vertebrae was 0.98, for low-thoracic vertebrae 0.97 and for lumbar vertebrae 0.97. Measurement exactness of the software was within 5° in 62% of cases and within 10° in 97% of cases. Intraclass correlation coefficient (ICC) for inter-observer reliability was 0.92 (0.91-0.95), ICC for intra-observer reliability was 0.96 (0.94-0.97). CONCLUSIONS: We developed a digital X-ray software tool to determine vertebral rotation in AIS with a substantial concurrent validity and reliability, which may be useful for the follow-up of vertebral rotation in AIS patients.

Cervical spine kinematics after anterior cervical discectomy with or without implantation of a mobile cervical disc prosthesis; an RCT.

BACKGROUND: When surgically treating cervical degenerative disc disease, the most commonly performed procedure is anterior cervical discectomy. This procedure is performed with, or without fusion promoting methods. For both options the rate of fusion is high and there is much debate whether fusion of the treated segment is a contributing factor to accelerated degeneration of adjacent motion segments. In an effort to prevent degeneration of adjacent segments (ASDeg) due to loss of mobility at the operated level, cervical disc arthroplasty (CDA) was introduced. To evaluate the effectiveness of CDA in preventing ASDeg long term studies are necessary. However, prevention of ASDeg is based on the premise that mobile disc prostheses preserve cervical spine motion in a physiological way. In this article the authors describe a short term protocol for a study that aims to investigate whether CDA reaches the intended goal: restoration or preservation of physiological cervical spine motion. To this end, a technique is used to establish the sequence of contributions of cervical motion segments to flexion/extension of the spine. METHODS: 24 subjects between 18 and 55 years old, with radicular symptoms due to a herniated disc between C5 and C7, refractory to conservative therapy are randomized to simple discectomy, or CDA. These groups are preceded by a pilot group of three subjects receiving CDA. Fluoroscopic flexion-extension recordings are acquired preoperatively, and at three and 12 months postoperative. At these same time points, patient reported outcomes are collected, and a neurological examination is performed by and independent physician. DISCUSSION: Studies investigating arthroplasty determine mobility by measuring segmental range of motion (sROM), which gives no information other than presence, and quantity, of mobility. SROM suffer from high variability. The authors therefore chose to use a method previously used in healthy controls, to describe the dynamic process of cervical spine motion in more detail. Determining cervical spine motion patterns has been reported to be more consistent than sROM. If a physiological motion pattern is absent after surgery in the CDA group, prevention of future ASDeg is less likely. Radiological outcomes will be correlated to clinical outcomes. TRIAL REGISTRATION: NCT00868335.

Arthroplasty versus fusion in single-level cervical degenerative disc disease: a Cochrane review.

STUDY DESIGN: A systematic review of randomized controlled trials (RCTs). OBJECTIVE: To assess the effects of arthroplasty versus fusion in the treatment of radiculopathy or myelopathy, or both, due to single-level cervical degenerative disc disease. SUMMARY OF BACKGROUND DATA: There is ongoing debate about whether fusion or arthroplasty is superior in the treatment of single-level cervical degenerative disc disease. Mainly because the intended advantage of arthroplasty compared with fusion, prevention of symptoms due to adjacent segment degeneration in the long term, is not confirmed yet. Until sufficient long-term results become available, it is important to know whether results of 1 of the 2 treatments are superior to the other in the first 1 to 2 years. METHODS: We searched electronic databases for randomized controlled trials. We included randomized controlled trials that directly compared any type of cervical fusion with any type of cervical arthroplasty, with at least 1 year of follow-up. Study selection was performed independently by 3 review authors, and "risk of bias" assessment and data extraction were independently performed by 2 review authors. In case of missing data, we contacted the study authors or the study sponsor. We assessed the quality of evidence. RESULTS: Nine studies (2400 participants) were included in this review; 5 of these studies had a low risk of bias. Results for the arthroplasty group were better than the fusion group for all primary comparisons, often statistically significant. For none of the primary outcomes was a clinically relevant difference in effect size shown. Quality of the evidence was low to moderate. CONCLUSION: There is low to moderate quality evidence that results are consistently in favor of arthroplasty, often statistically significant. However, differences in effect size were invariably small and not clinically relevant for all primary outcomes. LEVEL OF EVIDENCE: 1.

Arthroplasty versus fusion in single-level cervical degenerative disc disease.

BACKGROUND: There is ongoing debate about whether fusion or arthroplasty is superior in the treatment of single level cervical degenerative disc disease. Mainly because the intended advantage of arthroplasty over fusion, that is, the prevention of symptoms due to adjacent segment degeneration in the long term, is not confirmed yet. Until sufficient long-term results become available, it is important to know whether results of one of the two treatments are superior to the other in the first one to two years. OBJECTIVES: To assess the effects of arthroplasty versus fusion for radiculopathy or myelopathy, or both due to single level cervical degenerative disc disease. SEARCH METHODS: We searched the following databases for randomised controlled trials (RCTs): CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE, EMBASE, and EBMR. Additionally, we searched the System for Information on Grey Literature (SIGLE), subheading Biological and Medical Sciences, the US Food and Drug Administration (FDA) database on medical devices, and Clinicaltrials.gov to identify trials in progress. We also screened the reference list of all selected papers. Date of search: 25 May 2011. SELECTION CRITERIA: We included RCTs that directly compared any type of cervical fusion with any type of arthroplasty, with at least one year of follow-up. Primary outcomes were arm pain, neck pain, neck-related functional status, patient satisfaction, neurological outcome, and global health status. Secondary outcomes were the presence of (radiological) fusion, revision surgery at the treated level, secondary surgery on adjacent levels, segmental mobility of treated and adjacent levels, and work status. DATA COLLECTION AND ANALYSIS: Study selection was performed independently by three review authors, and 'Risk of bias' assessment and data extraction were performed by two review authors. In case of missing data or insufficient information for a judgement about risk of bias, we tried to contact the study authors or the study sponsor. The data were entered into RevMan by one review author and subsequently checked by a second review author. We assessed the quality of evidence using GRADE. We analysed heterogeneity and performed sensitivity analyses for the pooled analyses. MAIN RESULTS: We included nine studies (2400 participants), five of which had a low risk of bias. Eight of these studies were industry sponsored. The most important results showed low-quality evidence for a small but significant difference in alleviation of arm pain at one to two years in favour of arthroplasty (mean difference (MD) -1.54; 95% confidence interval (CI) -2.86 to -0.22; 100-point scale). A small study effect could not be ruled out for this outcome in the sensitivity analyses. This means that smaller studies (or small published subsets of larger studies) showed larger differences for this outcome, which may indicate publication bias. Also, moderate-quality evidence showed a small difference in neck-related functional status at one to two years in favour of arthroplasty (MD -2.79; 95% CI -4.73 to -0.85; 100-point scale) and a small difference in neurological outcome in favour of arthroplasty (risk ratio (RR) 1.05; 95% CI 1.01 to 1.09). These two outcomes were robust to sensitivity analyses. For none of the primary outcomes, was a clinically relevant difference shown. Additionally, there was high-quality evidence for a large, statistically significant difference in segmental mobility at one to two years (measured as degrees segmental range of motion) at the treated level (MD 6.90; 95% CI 5.45 to 8.35). There was low-quality evidence that there was no statistically significant difference in secondary surgery at the adjacent levels at one to two years (RR 0.60; 95% CI 0.35 to 1.02). The latter was not robust to sensitivity analyses. AUTHORS' CONCLUSIONS: There was a tendency for clinical results to be in favour of arthroplasty; often these were statistically significant. However, differences in effect size were invariably small and not clinically relevant for all primary outcomes. Significance was often gained or lost in the varying sensitivity analyses, probably owing to the relatively small number of studies, in combination with the small differences that were found. Given the fact that all of the included studies were not blinded, this could be due to patient or carer expectations. However, at this time both treatments can be seen as valid options with respect to results at a maximum of one to two years. Given the current absence of truly long-term results, use of these mobile disc prostheses should still be limited to clinical trials. There was high-quality evidence that the goal of preservation of segmental mobility in arthroplasty was met. A statistically significant effect on the incidence of secondary symptoms at adjacent levels, the primary goal of arthroplasty over fusion, was not found at one to two years. If there was a protective effect, this should become clearer over time. A future update, when studies with 'truly long-term' results (five years or more) become available, should focus on this issue.