Søren Peter Eiskjær

Interobserver and Intraobserver Agreement of Radiograph Interpretation With and Without Pedicle Screw Implants : The Need for a Detailed Classification System in Posterolateral Spinal Fusion

Study Design. A prospective randomized clinical study in which four observers evaluated radiographs of posterolateral fusion masses. Objectives. To evaluate the accuracy of radiograph interpretation of the posterolateral spinal fusion mass when using a detailed classification system and to analyze the influence of metallic internal fixation devices on radiologic inaccuracy. Summary of Background Data. In general, the literature describing the classification criteria used for radiograph interpretation of spinal posterolateral fusion has serious deficiencies. There is a need for a detailed classification system. Methods. Seventy patients were randomly allocated to receive no instrumentation (n = 36) or Cotrel–Dubousset instrumentation (n = 34) in posterolateral lumbar fusion. All four observers participated in a prestudy discussion and evaluated the radiographs (anteroposterior, lateral) taken at the 1-year follow-up evaluation. The observers scored the radiographs twice (30 days apart). Each level on each side was judged separately. A continuous intertransverse bony bridge involving at minimum one of the two sides indicated a fusion at that level. “Fusion” indicated this quality of fusion at all intended levels. If the fusion was doubtful on both sides of the interspace, the individual case could not be classified as “fused.” Results. The mean interobserver agreement was 86% (Kappa 0.53), and the mean intraobserver agreement was 93% (Kappa 0.78). No difference in interobserver and intraobserver agreement was found between patients with and without supplementary pedicle screw fixation. All mean Kappa values were classified as fair or good. The four observers identified a mean fusion rate of 81%. Conclusion. It is extremely difficult to interpret radiographic lumbar posterolateral fusion success. Such an assessment needs to be performed by use of a detailed radiographic classification system. The classification system presented here revealed good interobserver and intraobserver agreement, both with and without instrumentation. The classification showed acceptable reliability and may be one way to improve interstudy and intrastudycorrelation of radiologic outcomes after posterolateral spinal fusion. Instrumentation did not influence reproducibility but may result in slightly underestimated fusion rates.

Risk factors influencing mortality after bipolar hemiarthroplasty in the treatment of fracture of the femoral neck

The hospital records of 204 patients (mean age 80 years, range 54-96 years) with a displaced intracapsular femoral neck fracture treated by cemented bipolar hemiarthroplasty were examined to record all available data on factors suspected of influencing mortality. The data were analyzed statistically using survival analysis (Cox model). The six months mortality rate was 20% and the one year mortality rate was 28%. The following factors, in order to decreasing importance, had significant influence on mortality: cardiac factors other than previous myocardial infarction; status as a nursing home patient; chronic pulmonary disease; serum creatinine level greater than 1.7 mg/100 ml; pneumonia; previous myocardial infarction; duration of surgery; and gender. The following factors had no significant influence on mortality: age, time delay from admission to surgery, mode of anesthesia, and cerebrovascular diseases. In conclusion, medical conditions were the most important determinants of survival in the present study. The time delay between admission and surgery did not influence the chances of survival. This does not mean that surgical delay beyond that essential for stabilizing the patient is not problematic, but indicates that ample time should be spent on assessment and resuscitation before surgery.

Years of potential life lost after hip fracture among postmenopausal women

From January 1987 and onwards all cases of hip fracture in Arhus County, Denmark, were registered in a prospective multicenter investigation. Until December 1990, 2273 postmenopausal women (greater than 50 years) with first hip fractures were registered. Of these 643 sustained a hip fracture in 1988. Life tables were constructed for different age groups; the excess mortality (in comparison with the reference population) for each age group ranged from 10 to 20 percent. The years of potential life lost (YPLL) (life expectancy method) were calculated for the 1988 cohort and compared with the YPLL due to other selected conditions calculated from official vital statistics. The YPLL rates (per 1000 persons) were as follows: hip fracture 9.2, ischemic heart disease 73, cerebrovascular disease 29, breast cancer 20 and cancer of the uterus 6.7. We propose that hip fracture mortality data should be continuously registered and evaluated using the YPLL method to detect changes caused by the expected increase in the number of hip fractures.

Arthroscopy of the knee in children

Diagnostic arthroscopy was performed in 174 consecutive patients under the age of 18 years. Eight arthroscopies were bilateral. The clinical diagnosis was confirmed in only three of 17 knees in children under aged 14 years and in 44 per cent of the knees in older children. The most commonly disproved diagnoses were torn meniscus and chondromalacia patella. Arthroscopy seldom changed the diagnosis in cases of osteochondritis dissecans. In 38 per cent of the knees, arthroscopy revealed no surgical treatable abnormality, and unnecessary arthrotomy was avoided. Arthroscopy in acute hemarthrosis revealed that ligamentous tears are rather common in children; in nine of 25 knees a partial or complete tear of the anterior cruciate ligament was demonstrated at arthroscopy. The clinical diagnosis was confirmed in eight knees in cases of hemarthrosis. There was no significant difference between the hemarthrosis group and the remaining group as regards a disproved clinical diagnosis. We conclude that arthrotomy should always be preceded by diagnostic arthroscopy in children and adolescents if the clinical diagnosis leaves any doubt.

Functional outcome after posterolateral spinal fusion using pedicle screws: comparison between primary and salvage procedure

Abstract Lumbar spinal fusion is a commonly performed surgical procedure, yet both the indications for its performance and its results remain controversial. It is generally believed that apart from situations where obvious measurable instability exists, a repeat surgical procedure such as spinal fusion does not improve the functional outcome in more than an average of 50% of cases. The aim of this study was to analyse functional outcome after posterolateral lumbar or lumbosacral spinal fusion, comparing primary and salvage procedures. It was designed as a prospective case/referent study with a 2-year follow-up. A total of 39 patients underwent a short posterior fusion with Cotrel-Dubousset (CD) pedicle screw fixation after earlier surgery of the lumbar spine. Two patients were erroneously omitted from the study at the index, so 37 patients were included in the salvage group. In the same period, 69 patients underwent lumbar fusion with pedicle screw fixation (CD) as primary surgery (referent group). Functional outcome was assessed by means of the Dallas Pain Questionnaire preoperatively and 1 and 2 years postoperatively. Fusion rates were determined by ordinary X-ray evaluation by two independent observers. Patients who had undergone previous spinal surgery had a significant improvement in functional outcome in terms of daily activity, work and leisure-time activities and anxiety/depression. With regard to social functioning, a significantly inferior outcome was found after the salvage procedure. The return-to-work rates at 2 years after surgery were 50% in the salvage group and 53% in the referent group. There was a significant correlation between radiological evaluation of the fusion mass and the functional outcome. The fusion rate was 76% in the salvage group and 72% in the referent group. This study demonstrates that a posterolateral spinal fusion can be effectively used as a salvage procedure. The functional and radiological outcome of the patients with revision surgery did not differ from those of the group of patients who underwent primary surgery. There was, however a clear indication of inferior social functioning after revision surgery.

Can autologous bone culture predict spinal fusion capacity

Abstract The capacity of the individual patient to initiate osteoblast proliferation as a predictor for successful lumbar spinal fusion has not yet been reported. The objectives of this study were, first, to analyze the relationship between in vitro osteoblast proliferation and clinical bony fusion in the individual patient in order to predict the fusion outcome and, second, to measure the effect of preoperative tobacco smoking on osteoblast proliferation. Sixty-one patients (mean age 46 years) underwent posterolateral lumbar fusion in the period 1994–1995. Thirty-eight patients received CD pedicle screw implants and 23 received posterolateral fusions alone. During surgery, autogenous iliac bone was harvested and 1 g of trabecular bone without blood or bone marrow was then isolated for cell culturing. The cultures were classified as excellent (confluence within 4 weeks), good (confluence between 4 and 6 weeks) and poor (no or poor growth). Spine fusion was evaluated by two independent observers from plain anterior-posterior, lateral, and flexion/extension radiographs taken 1 year postoperatively, and the functional outcome was measured by the Dallas Pain Questionnaire (DPQ). Twenty-three patients had excellent, 19 good, and 19 poor in vitro osteoblast proliferation. Bony fusion was obtained in 77% of patients: 83% in the CD instrumentation group and 70% in the non-instrumentation group (NS). There was no significant correlation between osteoblast proliferation and spinal fusion or functional outcomes when analyzing the CD instrumentation and non-instrumentation groups together or separately. Elderly patients had a significantly poorer osteoblast proliferation than younger patients (P < 0.008). Preoperative tobacco consumption had no discernible effect on osteoblast proliferation, and no correlation between smoking and fusion was found. Further refinement of autologous osteoblast culturing may provide a biological tool for selection of patients who require biological enhancement of their bone fusion capacity. The poorer osteoblast proliferation related to advanced age supports the important negative biological influence of age on bony fusion. However, with more sensitive testing and better discrimination, other results are possible – or can in any event not be excluded.

EOS® Micro-Dose Protocol: First Full-Spine Radiation Dose Measurements in Anthropomorphic Phantoms and Comparisons with EOS Standard-Dose and Conventional Digital Radiology (CR)

STUDY DESIGN A comparative study of radiation dose measured in anthropomorphic phantoms. OBJECTIVES The aim of this study was to first report the first organ dose and effective dose measurements in anthropomorphic phantoms using the new EOS imaging micro-dose protocol in full-spine examinations, and to compare these measurements of radiation dose to measurements in the EOS standard-dose protocol and conventional digital radiology (CR). SUMMARY OF BACKGROUND DATA Few studies evaluating organ dose and effective dose for the EOS low-dose scanner exist, and mainly for the standard-dose protocol. To the best of our knowledge, no studies of effective dose based on anthropomorphic phantom measurements exist for the new micro-dose protocol. METHODS Two anthropomorphic phantoms, representing a 5-year-old (pediatric) and a 15-year-old (adolescent). The phantoms were exposed to EOS micro-dose and standard-dose protocols during full-spine imaging. Additionally, CR in scoliosis settings was performed. For all modalities, organ doses were measured and effective doses were calculated using thermoluminescent dosimeters. RESULTS We found a 17-fold reduction (94%) of effective dose in micro-dose protocol compared with our CR system in the adolescent phantom. Micro-dose versus standard-dose protocol, showed a 6-fold reduction (83%), and for standard-dose versus our CR system a 2.8-fold reduction (64%) reduction of effective dose was observed.For the pediatric phantom, a 5-fold reduction (81%) of effective dose in micro-dose protocol compared to our CR system was observed. Micro-dose versus standard-dose protocol, showed a seven-fold (86%) reduction. However, we observed an increase in absorbed dose of 38% when comparing the EOS standard-dose protocol with our CR system. CONCLUSION The EOS imaging micro-dose option exposes patients to lower radiation doses than any currently available modality for full-spine examination. Expected reduction of dose was established for the adolescent phantom when comparing CR and standard-dose protocol. However, no reduction of effective dose with EOS standard-dose protocol compared to our reference CR system was observed in the pediatric phantom. LEVEL OF EVIDENCE N/A.Study Design. A comparative study of radiation dose measured in anthropomorphic phantoms. Objectives. The aim of this study was to first report the first organ dose and effective dose measurements in anthropomorphic phantoms using the new EOS imaging micro-dose protocol in full-spine examinations, and to compare these measurements of radiation dose to measurements in the EOS standard-dose protocol and conventional digital radiology (CR). Summary of Background Data. Few studies evaluating organ dose and effective dose for the EOS low-dose scanner exist, and mainly for the standard-dose protocol. To the best of our knowledge, no studies of effective dose based on anthropomorphic phantom measurements exist for the new micro-dose protocol. Methods. Two anthropomorphic phantoms, representing a 5-year-old (pediatric) and a 15-year-old (adolescent). The phantoms were exposed to EOS micro-dose and standard-dose protocols during full-spine imaging. Additionally, CR in scoliosis settings was performed. For all modalities, organ doses were measured and effective doses were calculated using thermoluminescent dosimeters. Results. We found a 17-fold reduction (94%) of effective dose in micro-dose protocol compared with our CR system in the adolescent phantom. Micro-dose versus standard-dose protocol, showed a 6-fold reduction (83%), and for standard-dose versus our CR system a 2.8-fold reduction (64%) reduction of effective dose was observed. For the pediatric phantom, a 5-fold reduction (81%) of effective dose in micro-dose protocol compared to our CR system was observed. Micro-dose versus standard-dose protocol, showed a seven-fold (86%) reduction. However, we observed an increase in absorbed dose of 38% when comparing the EOS standard-dose protocol with our CR system. Conclusion. The EOS imaging micro-dose option exposes patients to lower radiation doses than any currently available modality for full-spine examination. Expected reduction of dose was established for the adolescent phantom when comparing CR and standard-dose protocol. However, no reduction of effective dose with EOS standard-dose protocol compared to our reference CR system was observed in the pediatric phantom. Level of Evidence: N/A

Lumbar spinal stenosis: comparison of surgical practice variation and clinical outcome in three national spine registries

BACKGROUND CONTEXT Decompression surgery for lumbar spinal stenosis (LSS) is the most common spinal procedure in the elderly. To avoid persisting low back pain, adding arthrodesis has been recommended, especially if there is a coexisting degenerative spondylolisthesis. However, this strategy remains controversial, resulting in practice-based variation. PURPOSE The present study aimed to evaluate in a pragmatic study if surgical selection criteria and variation in use of arthrodesis in three Scandinavian countries can be linked to variation in treatment effectiveness. STUDY DESIGN This is an observational study based on a combined cohort from the national spine registries of Norway, Sweden, and Denmark. PATIENT SAMPLE Patients aged 50 and older operated during 2011-2013 for LSS were included. OUTCOME MEASURES Patient-Reported Outcome Measures (PROMs): Oswestry Disability Index (ODI) (primary outcome), Numeric Rating Scale (NRS) for leg pain and back pain, and health-related quality of life (Euro-Qol-5D) were reported. Analysis included case-mix adjustment. In addition, we report differences in hospital stay. METHODS Analyses of baseline data were done by analysis of variance (ANOVA), chi-square, or logistic regression tests. The comparisons of the mean changes of PROMs at 1-year follow-up between the countries were done by ANOVA (crude) and analysis of covariance (case-mix adjustment). RESULTS Out of 14,223 included patients, 10,890 (77%) responded at 1-year follow-up. Apart from fewer smokers in Sweden and higher comorbidity rate in Norway, baseline characteristics were similar. The rate of additional fusion surgery (patients without or with spondylolisthesis) was 11% (4%, 47%) in Norway, 21% (9%, 56%) in Sweden, and 28% (15%, 88%) in Denmark. At 1-year follow-up, the mean improvement for ODI (95% confidence interval) was 18 (17-18) in Norway, 17 (17-18) in Sweden, and 18 (17-19) in Denmark. Patients operated with arthrodesis had prolonged hospital stay. CONCLUSIONS Real-life data from three national spine registers showed similar indications for decompression surgery but significant differences in the use of concomitant arthrodesis in Scandinavia. Additional arthrodesis was not associated with better treatment effectiveness.

Nano-Dose Protocol for 3D Reconstruction of the Spine in Early Onset Scoliosis: Preliminary Results of a Phantom Based and Clinically Validated Study using Stereo-Radiography

This is a prospective study validating the reproducibility of 3D reconstruction of the spine using a new reduced micro-dose protocol. A pilot group of children with scoliosis underwent micro-dose- and additional reduced micro-dose (nano-dose) full-spine imaging. 3D reconstructions of both protocols were evaluated.

Predictors of Hospital Re-admission and Surgical Site Infection in the United States, Denmark and Japan: Is Risk Stratification a Universal Language?

Study Design. Retrospective review of three spine surgery databases. Objectives. The purpose of the present study is to determine whether predictors of hospital readmission and surgical site infection (SSI) after lumbar fusion will be the same in United States, Denmark, and Japan. Summary of Background Data. Because clinical decision making becomes more data driven, risk stratification will be crucial to minimize complications. Spine surgeons worldwide face this issue, leading to parallel efforts to address risk stratification. This raises the question as to whether pooled data would be valuable and whether models generated in one country would be applicable to other populations. Methods. Predictors of SSI and 30-day readmission from three prospective databases (National Neurosurgery Quality and Outcomes Database [N2QOD] N = 2653, DaneSpine N = 1993, Japan Multicenter Spine Database [JAMSD] N = 3798) were determined and compared to identify common or divergent predictive risks. Results. Predictive variables differed in the three databases, for both readmission and SSI. Factors predictive for hospital readmission were American Society of Anesthesiologists (ASA) grade in N2QOD (P = 0.013, odds ratio [OR] 2.08), fusion levels in DaneSpine (P = 0.005, OR 1.67), and sex in JAMSD (P = 0.001, OR = 2.81). Associated differences in demographics and procedural factors included mean ASA grade (N2QOD = 2.45, JAMSD = 1.72) and fusion levels (N2QOD = 1.39, DaneSpine = 1.52, JAMSD = 1.34). For SSI, sex (P = 0.000, OR = 3.30), diabetes (P = 0.000, OR = 2.90), and length of stay (P = 0.000, OR = 1.02) were predictive in JAMSD. No predictors were identified in N2QOD or DaneSpine. Conclusion. Predictors of SSI and hospital readmission differ in the United States, Denmark, and Japan, suggesting that risk stratification models may need to be population specific or adjusted. Some differences in measured parameters exist in the three databases analyzed; however, patient and procedure selection also appear to differ and may limit the ability to directly pool data from different regions. Therefore, risk stratification models developed in one country may not be directly applicable to other countries. Level of Evidence: 2