Nutritional status as independent prognostic factor of outcome and mortality until five years after hip fracture: a comprehensive prospective study.

We determined the prognostic value of nutritional status for outcome after hip fracture. Nutritional status was a strong independent prognostic factor for clinical outcome and 5-year mortality. Physical function showed incomplete recovery. Elderly care should focus on prevention already before hip fracture. PURPOSE: To determine the prognostic value of nutritional status in hip fracture patients for multiple clinical and functional outcomes over 6 months, and for new fractures and survival over 5 years post-fracture. METHODS: We included 152 well-characterized subjects (age 55+ years) with a hip fracture from a previously published randomized controlled trial. Nutritional status was appraised using the Mini Nutritional Assessment (MNA). Multivariable linear, logistic and Cox regression models were fitted, adjusted for age, sex, ASA score, group and additional prognostic covariates identified in backward regression models. RESULTS: At baseline, impaired nutritional status was significantly associated with physical disability, depression, impaired cognition and lower quality of life. Prospective analyses showed that impaired baseline nutritional status was an independent prognostic factor for postoperative complications (OR 2.00, 95%CI 1.01-3.98, p = 0.047), discharge location from hospital (home vs. rehabilitation clinic, OR 0.41, 95%CI 0.18-0.98, p = 0.044), hospital readmission (OR 4.59, 95%CI 1.70-12.4, p = 0.003) and total length of hospital stay (HR of being discharged: 0.63, 96%CI 0.44-0.89, p = 0.008), as well as for 5-year mortality (HR 3.94, 95%CI 1.53-10.2, p = 0.005), but not for risk of new fractures (5y-HR 0.87, 95%CI 0.34-2.24, p = 0.769). Curves of physical disability over time showed that the three nutritional status categories followed almost parallel trajectories from baseline until 6 months after hip fracture, without complete recovery and even with further deterioration in malnourished subjects from 3 to 6 months post-fracture. CONCLUSION: As baselline nutritional status is a strong independent prognostic factor for clinical outcome after hip fracture, affecting even five-year survival, elderly health care should focus on prevention and identification of at-risk individuals already before hip fracture.

Radiomics biopsy signature for predicting survival in patients with spinal bone metastases (SBMs).

STUDY DESIGN: Retrospective analysis of a registered cohort of patients treated and irradiated for metastases in the spinal column in a single institute. OBJECTIVE: This is the first study to develop and internally validate radiomics features for predicting six-month survival probability for patients with spinal bone metastases (SBM). BACKGROUND DATA: Extracted radiomics features from routine clinical CT images can be used to identify textural and intensity-based features unperceivable to human observers and associate them with a patient survival probability or disease progression. METHODS: A study was conducted on 250 patients treated for metastases in the spinal column irradiated for the first time between 2014 and 2016, at the MAASTRO clinic in Maastricht, the Netherlands. The first 150 available patients were used to develop the model and the subsequent 100 patient were considered as a test set for the model. A bootstrap (B = 400) stepwise model selection, which combines both the forward and backward variable elimination procedure, was used to select the most useful predictive features from the training data based on the Akaike information criterion (AIC). The stepwise selection procedure was applied to the 400 bootstrap samples, and the results were plotted as a histogram to visualize how often each variable was selected. Only variables selected more than 90 % of the time over the bootstrap runs were used to build the final model.A prognostic index (PI) called radiomics score (radscore) and clinical score (clinscore) was calculated for each patient. The prognostic index was not scaled, the original values were used which can be extracted from the model directly or calculated as a linear combination of the variables in the model multiplied by the respective beta value for each patient. RESULTS: The clinical model had a good discrimination power. The radiomics model, on the other hand, had an inferior performance with no added predictive power to the clinical model. The internal imaging characteristics do not seem to have a value in the prediction of survival. However, the Shape features were excluded from further analyses in our study since all biopsies had a standard shape hence no variability.

The Use of Metal Sublaminar Wires in Modern Growth-Guidance Scoliosis Surgery: A Report of 4 Cases and Literature Review.

BACKGROUND: To avoid early fusion and allow residual growth of the spine in early onset scoliosis (EOS) treatment, growth-guided scoliosis surgery can be performed. Four patients with EOS are presented in which a growth-guidance instrumentation is used with sliding titanium (Ti) sublaminar cables. Residual growth of the spine can be preserved using metal sublaminar wiring; however, several drawbacks of this technique and type of material are illustrated. METHODS: Four patients with progressive neuromuscular scoliosis were treated with a posterior stabilization. A fusionless growth-guidance instrumentation was used consisting of a combination of lumbar pedicle screws and sliding Ti sublaminar cables along cobalt chrome rods. RESULTS: In 2 cases, the described growth-guidance technique provided sufficient stability and correction of the curvature with preservation of growth. In 2 patients, the instrumentation failed due to upper thoracic sublaminar wire breakage. The ongoing abrasion of the rod-wire interface caused severe metallosis. In these cases, a debridement and revision surgery was performed with partial fusion of the spine. CONCLUSIONS: Growth-guidance techniques with sliding metal sublaminar wires seem to be a valuable solution for the preservation of spinal growth in EOS surgery. High curvatures, however, have a higher chance of failure and demand for more corrective strength and support of the instrumentation. The use of metal sublaminar wires in a "sliding" instrumentation can lead to early breakage and metallosis. LEVEL OF EVIDENCE: 4, case series. CLINICAL RELEVANCE: Surgeons should be aware of possible complications associated with the use of metal laminar wires in spinal fusion and growth-guidance scoliosis surgery. The implementation of materials containing higher fatigue strength and lower friction properties (eg, UHMWPE wires) may avoid these potential complication risks.

Subsidence after total lumbar disc replacement is predictable and related to clinical outcome.

PURPOSE: As yet, there are no studies describing a relationship between radiographic subsidence after lumbar total disc replacement (TDR) and patient symptoms. To investigate if subsidence, in terms of penetrated bone volume or angular rotation over time (ΔPBV and ΔAR), is related to clinical outcome. To assess if subsidence can be predicted by position implant asymmetry (IA) or relative size of the TDR, areal undersizing index (AUI) on direct post-operative radiographs. METHODS: Retrospective cohort study consists of 209 consecutive patients with lumbar TDR for degenerative disc disease. A three-dimensional graphical representation of the implant in relation to the bony endplates was created on conventional radiographs. Consequently, the PBV, AR, IA and AUI were calculated, direct post-operative (DPO) and at last follow-up (LFU). For clinical evaluation, patients with substantial pain (VAS ≥ 50) and malfunction (ODI ≥ 40) were considered failures. RESULTS: At a mean follow-up of 16.7 years, 152 patients (73%) were available for analysis. In 32 patients, revision by spinal fusion had been performed. Both ΔAR (4.33° vs. 1.83°, p = 0.019) and ΔPBV (1448.4 mm3 vs. 747.3 mm3, p = 0.003) were significantly higher in the failure-compared to the success-group. Using ROC curves, thresholds for symptomatic subsidence were defined as ΔPBV ≥ 829 mm3 or PBV-LFU ≥ 1223 mm3 [area under the curve (AUC) 0.723, p = 0.003 and 0.724, p = 0.005, respectively]. Associations between symptomatic subsidence and AUI-DPO ≥ 0.50 (AUC 0.750, p = 0.002) and AR-DPO ≥ 3.95° (AUC 0.690, p = 0.022) were found. CONCLUSION: Subsidence of a TDR is associated with a worse clinical outcome. The occurrence of subsidence is higher in case of incorrect placement or shape mismatch.

Percutaneous cement augmentation in the treatment of osteoporotic vertebral fractures (OVFs) in the elderly: a systematic review.

PURPOSE: A systematic review, to study treatment effects for osteoporotic vertebral fractures (OVFs) in the elderly including all available evidence from controlled trials on percutaneous cement augmentation. METHODS: Primary studies, published up to December, 2019, were searched in PubMed and the Cochrane Library. Selected were all prospective controlled studies including patients > 65 years of age and reporting on at least one main outcome. Main outcomes were pain, disability and quality of life (QOL) 1 day post-intervention and at 6 months postoperatively. Excluded were meta-analyses or reviews, retrospective or non-controlled studies, case studies, patients' groups with neoplastic and/or traumatic fractures and/or neurologically compromised patients. RESULTS: Eighteen studies comprising 2165 patients (n = 1117 percutaneous cement augmentation, n = 800 conservative treatment (CT), n = 248 placebo) with a mean follow-up of up to 12 months were included. Pooled results showed significant pain relief in favor of percutaneous cement augmentation compared to CT, direct postoperative and at 6 months follow-up. At 6 months, a significant difference was observed for functional disability scores in favor of percutaneous cement augmentation. When comparing percutaneous cement augmentation to placebo, no significant differences were observed. CONCLUSION: This review incorporates all current available evidence (RCTs and non-RCTs) on the efficacy of percutaneous cement augmentation in the treatment of OVFs in the elderly. Despite methodological heterogeneity of the included studies, this review shows overall significant sustained pain relief and superior functional effect in the short- and long term for percutaneous cement augmentation compared to conservative treatment. These slides can be retrieved under Electronic Supplementary Material.

Long-term clinical outcome of the Charité III total lumbar disc replacement.

PURPOSE: To compare the long-term clinical results and complications of two revision strategies for patients with failed total disc replacements (TDRs). METHODS: In 19 patients, the TDR was removed and the intervertebral defect was filled with a femoral head bone strut graft. In addition, instrumented posterolateral fusion was performed (removal group). In 36 patients, only a posterolateral instrumented fusion was performed (fusion group). Visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed. RESULTS: The median follow-up was 12.3 years (range 5.3-24.3). In both the removal and fusion group, a similar (p = 0.515 and p = 0419, respectively) but significant decrease in VAS- (p = 0.001 and p = 0.001, respectively) and ODI-score (p = 0.033 and p = 0.013, respectively) at post-revision surgery compared to pre-revision surgery was seen. A clinically relevant improvement in VAS- and ODI-score was found in 62.5% and 43.8% in the removal group and in 43.5% and 39.1% in the fusion group (p = 0.242 and p = 0.773, respectively). Removal of the TDR was associated with substantial intra-operative complications such as major vessel bleeding and ureter lesion. The percentage of late reoperations for complications such as pseudarthrosis was comparable for both revision strategies. CONCLUSIONS: Revision of a failed TDR is clinically beneficial in about half of the patients. No clear benefits for additional TDR removal as compared to posterolateral instrumented fusion alone could be identified. Particularly, when considering the substantial risks and complications, great caution is warranted with removal of the TDR. These slides can be retrieved under Electronic Supplementary Material.

Reliability and Clinical Usefulness of Current Classifications in Traumatic Thoracolumbar Fractures: A Systematic Review of the Literature.

BACKGROUND: A validated classification remains the key to an appropriate treatment algorithm of traumatic thoracolumbar fractures. Considering the development of many classifications, it is remarkable that consensus about treatment is still lacking. We conducted a systematic review to investigate which classification can be used best for treatment decision making in thoracolumbar fractures. METHODS: A comprehensive search was conducted using PubMed, Embase, CINAHL, and Cochrane using the following search terms: classification (mesh), spinal fractures (mesh), and corresponding synonyms. All hits were viewed by 2 independent researchers. Papers were included if analyzing the reliability (kappa values) and clinical usefulness (specificity or sensitivity of an algorithm) of currently most used classifications (Magerl/AO, thoracolumbar injury classification and severity score [TLICS] or thoracolumbar injury severity score, and the new AO spine). RESULTS: Twenty articles are included. The presented kappa values indicate moderate to substantial agreement for all 3 classifications. Regarding the clinical usefulness, > 90% agreement between actual treatment and classification recommendation is reported for most fractures. However, it appears that over 50% of the patients with a stable burst fracture (TLICS 2, AO-A3/A4) in daily practice are operated, so in these cases treatment decision is not primarily based on classification. CONCLUSION: AO, TLICS, and new AO spine classifications have acceptable accuracy (kappa > 0.4), but are limited in clinical usefulness since the treatment recommendation is not always implemented in clinical practice. Differences in treatment decision making arise from several causes, such as surgeon and patient preferences and prognostic factors that are not included in classifications yet. The recently validated thoracolumbar AO spine injury score seems promising for use in clinical practice, because of inclusion of patient-specific modifiers. Future research should prove its definite value in treatment decision making. LEVEL OF EVIDENCE: 2. CLINICAL RELEVANCE: Without the appropriate treatment, the impact of traumatic thoracolumbar fractures can be devastating. Therefore it is important to achieve consensus in the treatment of thoracolumbar fractures.

Long-term clinical outcome of two revision strategies for failed total disc replacements.

PURPOSE: To compare the long-term clinical results and complications of two revision strategies for patients with failed total disc replacements (TDRs). METHODS: In 19 patients, the TDR was removed and the intervertebral defect was filled with a femoral head bone strut graft. In addition, instrumented posterolateral fusion was performed (removal group). In 36 patients, only a posterolateral instrumented fusion was performed (fusion group). Visual Analogue Scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed. RESULTS: The median follow-up was 12.3 years (range 5.3-24.3). In both the removal and fusion groups, a similar (p = 0.515 and p = 0419, respectively) but significant decrease in VAS (p = 0.001 and p = 0.001, respectively) and ODI score (p = 0.033 and p = 0.013, respectively) at post-revision surgery compared to pre-revision surgery was seen. A clinically relevant improvement in VAS and ODI score was found in 62.5% and 43.8% in the removal group and in 43.5% and 39.1% in the fusion group (p = 0.242 and p = 0.773, respectively). Removal of the TDR was associated with substantial intra-operative complications such as major vessel bleeding and ureter lesion. The percentage of late re-operations for complications such as pseudarthrosis were comparable for both revision strategies. CONCLUSIONS: Revision of a failed TDR is clinically beneficial in about half of the patients. No clear benefits for additional TDR removal as compared to posterolateral instrumented fusion alone could be identified. In particular, when considering the substantial risks and complications, great caution is warranted with removal of the TDR. These slides can be retrieved under Electronic Supplementary Material.

Long-term functional outcome of distal radius fractures is associated with early post-fracture bone stiffness of the fracture region: An HR-pQCT exploratory study.

Identifying determinants of long-term functional outcome after a distal radius fracture is challenging. Previously, we reported on the association between early HR-pQCT measurements and clinical outcome 12 weeks after a conservatively treated distal radius fracture. We extended the follow-up and assessed functional outcome after two years in relation to early HR-pQCT derived bone parameters. HR-pQCT scans of the fracture region were performed in 15 postmenopausal women with a distal radius fracture at 1-2 (baseline), 3-4 weeks and 26 months post-fracture. Additionally, the contralateral distal radius was scanned at baseline. Bone density, micro-architecture parameters and bone stiffness using micro-finite element analysis (µFEA) were evaluated. During all visits, wrist pain and function were assessed using the patient-rated wrist evaluation questionnaire (PRWE), quantifying functional outcome with a score between 0 and 100. Two-year PRWE was associated with torsional and bending stiffness 3-4 weeks post-fracture (R2: 0.49, p = 0.006 and R2: 0.54, p = 0.003, respectively). In contrast, early micro-architecture parameters of the fracture region or contralateral bone parameters did not show any association with long-term outcome. This exploratory study indicates that HR-pQCT with µFEA performed within four weeks after a distal radius fracture captures biomechanical fracture characteristics that are associated with long-term functional outcome and therefore could be a valuable early outcome measure in clinical trials and clinical practice.

The Development of a Representative Porcine Early-Onset Scoliosis Model With a Standalone Posterior Spinal Tether.

STUDY DESIGN: In vivo analysis in a porcine model. OBJECTIVES: To develop a porcine experimental scoliosis model representative of early-onset scoliosis (EOS) with the use of a radiopaque ultra-high molecular weight polyethylene (UHMWPE) posterior spinal tether. SUMMARY OF BACKGROUND DATA: Large animal experimental scoliosis models with substantial growth potential are needed to test new fusionless scoliosis correction techniques. Previously described scoliosis models involve rib procedures, which violate the thoracic cage and affect subsequent corrective procedures. Models omitting these rib procedures have experienced difficulties in producing persistent three-dimensional structural deformities representative of EOS. METHODS: Scoliosis was induced in 14 immature pigs using an asymmetric posterior radiopaque UHMWPE spinal tether fixated to an offset device at lumbar and thoracic levels. Radiographs were taken at 2-week intervals, and frontal and sagittal Cobb angles were measured. A tether release was performed at the 10-week follow-up, and the animals were observed for another 10 weeks. RESULTS: Four animals had complications (infections and/or screw breakout) and were excluded from the study. Eight animals developed progressive curves with a mean frontal Cobb angle of 62°. A thoracic lordosis (34°) and a thoracolumbar kyphosis (22°) formed. CT analysis, acquired prior to tether release, showed a mean vertebral rotation of 37° at the apex with a mean vertebral wedge angle of 10°. After tether release, the frontal Cobb angles decreased to 46° at the 20-week follow-up. Sagittal curvature was not substantially affected after tether release. CONCLUSIONS: We describe a large animal scoliosis model, which exhibits a substantial deformity in three planes without the use of rib procedures additional to a posterior spinal tether. The created deformities showed persistence after tether release. With the management of infection and enhancement of instrumentation stability, the creation of a valid model for testing new devices in fusionless scoliosis surgery seems feasible. LEVEL OF EVIDENCE: Level V.

Dutch multidisciplinary guideline for invasive treatment of pain syndromes of the lumbosacral spine

OBJECTIVES: When conservative therapies such as pain medication or exercise therapy fail, invasive treatment may be indicated for patients with lumbosacral spinal pain. The Dutch Society of Anesthesiologists, in collaboration with the Dutch Orthopedic Association and the Dutch Neurosurgical Society, has taken the initiative to develop the guideline "Spinal low back pain," which describes the evidence regarding diagnostics and invasive treatment of the most common spinal low back pain syndromes, that is, facet joint pain, sacroiliac joint pain, coccygodynia, pain originating from the intervertebral disk, and failed back surgery syndrome. METHODS: The aim of the guideline is to determine which invasive treatment intervention is preferred for each included pain syndrome when conservative treatment has failed. Diagnostic studies were evaluated using the EBRO criteria, and studies on therapies were evaluated with the Grading of Recommendations Assessment, Development and Evaluation system. For the evaluation of invasive treatment options, the guideline committee decided that the outcome measures of pain, function, and quality of life were most important. RESULTS: The definition, epidemiology, pathophysiological mechanism, diagnostics, and recommendations for invasive therapy for each of the spinal back pain syndromes are reported. DISCUSSION: The guideline committee concluded that the categorization of low back pain into merely specific or nonspecific gives insufficient insight into the low back pain problem and does not adequately reflect which therapy is effective for the underlying disorder of a pain syndrome. Based on the guideline "Spinal low back pain," facet joint pain, pain of the sacroiliac joint, and disk pain will be part of a planned nationwide cost-effectiveness study.

Novel radiopaque ultrahigh molecular weight polyethylene sublaminar wires in a growth-guidance system for the treatment of early-onset scoliosis: feasibility in a large animal study.

STUDY DESIGN: In vivo analysis in an ovine model. OBJECTIVE: To evaluate the feasibility of radiopaque ultrahigh molecular weight polyethylene (UHMWPE) sublaminar wires in a growth-guidance spinal system by assessing stability, biocompatibility, and growth potential. SUMMARY OF BACKGROUND DATA: Several growth-guidance systems have been developed for the treatment of early-onset scoliosis. The use of gliding pedicle screws and metal sublaminar wires during these procedures can cause metal-on-metal debris formation and neurological deficits. Novel radiopaque UHMWPE wires are introduced to safely facilitate longitudinal growth and provide stability in a growth-guidance system for early-onset scoliosis. METHODS: Twelve immature sheep received posterior segmental spinal instrumentation; pedicle screws were inserted at L5 and radiopaque UHMWPE (bismuth trioxide) wires were passed sublaminarly at each level between L3 and T12 and fixed to dual cobalt-chromium rods. Four age-matched animals that were not operated were evaluated to serve as a control group. Radiographs were obtained to measure growth of the instrumented segment. After 24 weeks, the animals were killed and the spines were harvested for histological evaluation and high-resolution peripheral quantitative computed tomographic analysis. RESULTS: No neurological deficits occurred and all instrumentation remained stable. One animal died from an unknown cause. Substantial growth occurred in the instrumented segments (L5-T11) in the intervention group (27 ± 2 mm), which was not significantly different to the control group, (30 ± 4 mm, P = 0.42). High-resolution peripheral quantitative computed tomographic analysis clearly showed safe routing and fixation of the UHMWPE wires and instrumentation. Despite the noted growth, ectopic bone formation with the formation of bony bridges was observed in all animals. Histology revealed no evidence of chronic inflammation or wear debris. CONCLUSION: This study shows the first results of radiopaque UHMWPE sublaminar wires as part of a growth-guidance spinal system. UHMWPE sublaminar wires facilitated near-normal longitudinal spinal growth. All instrumentation remained stable throughout follow-up; no wire breakage or loosening occurred and no adverse local-tissue response to these wires was observed. LEVEL OF EVIDENCE: N/A.

Cost-effectiveness of nutritional intervention in elderly subjects after hip fracture. A randomized controlled trial.

UNLABELLED: Hip fracture patients can benefit from nutritional supplementation during their recovery. Up to now, cost-effectiveness evaluation of nutritional intervention in these patients has not been performed. Costs of nutritional intervention are relatively low as compared with medical costs. Cost-effectiveness evaluation shows that nutritional intervention is likely to be cost-effective. INTRODUCTION: Previous research on the effect of nutritional intervention on clinical outcome in hip fracture patients yielded contradictory results. Cost-effectiveness of nutritional intervention in these patients remains unknown. The aim of this study was to evaluate cost-effectiveness of nutritional intervention in elderly subjects after hip fracture from a societal perspective. METHODS: Open-label, multi-centre randomized controlled trial investigating cost-effectiveness of intensive nutritional intervention comprising regular dietetic counseling and oral nutritional supplementation for 3 months postoperatively. Patients allocated to the control group received care as usual. Costs, weight and quality of life were measured at baseline and at 3 and 6 months postoperatively. Incremental cost-effectiveness ratios (ICERs) were calculated for weight at 3 months and quality adjusted life years (QALYs) at 6 months postoperatively. RESULTS: Of 152 patients enrolled, 73 were randomized to the intervention group and 79 to the control group. Mean costs of the nutritional intervention was 613 Euro. Total costs and subcategories of costs were not significantly different between both groups. Based on bootstrapping of ICERs, the nutritional intervention was likely to be cost-effective for weight as outcome over the 3-month intervention period, regardless of nutritional status at baseline. With QALYs as outcome, the probability for the nutritional intervention being cost-effective was relatively low, except in subjects aged below 75 years. CONCLUSION: Intensive nutritional intervention in elderly hip fracture patients is likely to be cost-effective for weight but not for QALYs. Future cost-effectiveness studies should incorporate outcome measures appropriate for elderly patients, such as functional limitations and other relevant outcome parameters for elderly.

Single or double-level anterior interbody fusion techniques for cervical degenerative disc disease.

BACKGROUND: The number of surgical techniques for decompression and solid interbody fusion as a treatment for cervical spondylosis has increased rapidly, but the rationale for the choice between different techniques is unclear. OBJECTIVES: The goal of this study was to determine which method of anterior cervical interbody fusion at a single or double-level provides the best clinical and radiological outcome in patients with degenerative disc disease. SEARCH STRATEGY: Studies were identified with a computer-assisted search of electronic databases in the Cochrane Central Register of Controlled Trials (Issue 1, 2004), MEDLINE (1966 to 2004), EMBASE (1980 to 2004), and Current Contents (1996 to 2004). We also searched references of selected articles. SELECTION CRITERIA: With the aid of a checklist, two reviewers independently screened the identified references. Consensus was reached through negotiation. A third reviewer was consulted if consensus could not be reached. Inclusion criteria included: articles were reports of randomised comparative studies; treatments compared anterior cervical decompression and interbody fusion techniques, participants were individuals scheduled for surgery for a chronic (longer than 12 weeks) diagnosis of degenerative disc disease. DATA COLLECTION AND ANALYSIS: Methodological quality was assessed independently by two reviewers, using the van Tulder list of criteria. With the aid of a data extraction form, data was extracted independently by two reviewers on group characteristics, intervention details and outcome measures. MAIN RESULTS: Fourteen studies with 939 patients evaluated three comparisons of different fusion techniques. From these comparisons it appears that discectomy alone has a shorter operation time, hospital stay, and post-operative absence from work than discectomy with fusion, while there is no statistical difference for pain relief and rate of fusion. It also appears that fusion techniques that use autograft give a better chance for fusion than interbody fusion techniques that use a cage, but other outcome variables could not be combined. REVIEWERS' CONCLUSIONS: The low quality of the trials prohibits extensive conclusions from this review. More studies with better methodology and reporting are needed. There should be a more general agreement between researchers on which outcome parameters should be used in the evaluation of anterior cervical fusion procedures.

The effect of a plaster cast on lumbosacral joint motion. An in vivo assessment with precision motion analysis system.

STUDY DESIGN: This study was conducted to assess the effect of a plaster cast on the mobility of the lumbosacral joint in 10 patients with chronic low back pain. During static and dynamic exercises, movements between the proximal vertebra (L4 or L5) and the sacrum were registered in 10 patients without a support and after the application of a plaster cast, and with and without unilateral hip immobilization, respectively. OBJECTIVES: To investigate whether plaster casts actually immobilize the lumbosacral joint. SUMMARY OF BACKGROUND DATA: The presumed stabilizing effect of a lumbar orthosis on the lumbosacral joint has been the subject of many studies in the past years, and contradictory reports have been published. METHODS: The measurements were performed by means of Precision Motion Analysis System, an optoelectronic three-dimensional motion analysis system using infrared light. The patients were asked to perform maximal spinal flexion to extension, maximal pelvic tilt (static test conditions), and to walk within the measurement volume (dynamic test condition). This procedure was repeated with the patients wearing a plaster cast with and without unilateral hip fixation. Mobility was expressed in translations and rotations around three axes. For statistical analysis, repeated measurements two-way analysis of variance was used. RESULTS: Considerable rotations were found only in the sagittal plane. Both plaster casts appeared to decrease mobility during the static test conditions. During the dynamic test condition, however, no significant decrease of mobility of the lumbosacral joint by either of the casts could be observed. In both cast conditions, considerably more sagittal rotation was found during walking than with the other two exercises. CONCLUSION: In the sagittal plane, a plaster cast with or without unilateral hip immobilization can decrease motion during spinal flexion-extension. This stabilizing effect on the lumbosacral joint could not be observed during walking.