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 intrastudy correlation of radiologic outcomes after posterolateral spinal fusion. Instrumentation did not influence reproducibility but may result in slightly underestimated fusion rates.

Functional outcome after partial reduction and 360 degree fusion in grade III-V spondylolisthesis in adolescent and adult patients.

Reduction of high-grade spondylolisthesis is a surgically demanding procedure, which has been reported to incur a relatively high risk of neurologic damage, pseudoarthrosis, and other complications. The aim of this study was to evaluate the radiographic and functional outcome in spondylolisthesis grade III-V, surgically treated with posterior decompression, L4- or L5-S1 CD instrumentation, partial reduction, and posterolateral fusion followed by anterior interbody fusion L5-S1 ad modum Kellogg-Speed. Thirteen patients, mean age 23.8 (range, 11-33) years were followed for mean 28.5 (range, 19-52) months. The anterior slip, lumbosacral angle, sagittal rotation angle and L4/SI angle were significantly improved from preoperatively to follow-up. No patients had neurologic, vascular, thromboembolic, or lung complications. Twelve patients reported a better or unchanged (3 patients) physical and emotional status. At follow-up, 10 patients were in full-time jobs or back to school. The method was safe and provided a stable rigid fixation with partial reduction of the deformity and a satisfactory functional outcome.

[Results after surgical treatment of unstable thoracolumbar fractures]. / Resultat efter operativ behandling af ustabile torakolumbale columnafrakturer.

Seventy-eight patients with unstable, one-level fracture of the thoracolumbar spine and no neurological impairment were treated with short segment fixation, transpedicular autologous bone transplantation and posterolateral fusion. Kyphotic deformity and anterior column height improved significantly. Complications consisted of one case of late deep infection, three cases of seroma, four cases with 5 mm schantz screw breakage and two cases with screw loosening. Mild to moderate pain was present in 79% of the patients at follow-up, median 32 (13-72) months. Sixty-seven percent of the patients had returned to previous activity levels of employment. Short posterior internal fixation, transpedicular transplantation and posterolateral fusion allowed neurologically intact patients to be mobilized early, to spend median 12 days in hospital, and carried no risk of deterioration in neurological function.

[The effect of pedicle screw instrumentation on posterolateral spinal fusion. A prospective, randomized study with a two-year follow-up]. / Effekten af pedikelskrueinstrumentering ved posterolateral lumbal spondylodese. Et prospektivt randomiseret studium med to års opfølgning.

The aim was to evaluate the effect of supplementary pedicle screw fixation (Cotrel-Dubousset [CD]) in posterolateral lumbar spinal fusion. The study comprises 130 patients undergoing lumbar or lumbosacral fusion for spondyloisthesis grades I-II or degenerative segmental instability conditions. The patients were randomly allocated for no instrumentation (n = 66) or CD instrumentation (n = 64) in posterolateral lumbar fusion. A 97.7% follow-up was achieved. There were no significant differences between the two groups concerning fusion rates assessed by X-ray or functional outcomes assessed by Dallas Pain Questionnaire. The global patient satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group. Instrumentation increased both operation time, blood loss, and early re-operation rates significantly. A high patient satisfaction was found in both groups. However, the results from this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

Can autologous bone culture predict spinal fusion capacity?

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.

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

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.

1997 Volvo Award winner in clinical studies. The effect of pedicle screw instrumentation on functional outcome and fusion rates in posterolateral lumbar spinal fusion: a prospective, randomized clinical study.

STUDY DESIGN: A prospective randomized clinical study. OBJECTIVES: To evaluate supplementary pedicle screw fixation (Cotrel-Dubousset) in posterolateral lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: The rationale behind lumbar fusion is to eliminate pathologic motion to relieve pain. To improve fusion rates and to allow reduction, a rigid transpedicular screw fixation may be beneficial, but the positive effect of this may be counter-balanced by an increase in complications. METHODS: The inclusion criteria were severe, chronic low back pain from spondylolisthesis Grades 1 and 2 or from primary or secondary degenerative segmental instability. One hundred thirty patients were randomly allocated to receive no instrumentation (n = 66) or Cotrel-Dubousset instrumentation (n = 64) in posterolateral lumbar fusion. Variables were registered at the time of surgery and at 1 and 2 years after surgery. RESULTS: Follow-up was achieved in 97.7% of the patients. Fusion rates deduced from plain radiographs were not significantly different between instrumented and noninstrumented groups. The functional outcome assessed by the Dallas Pain Questionnaire improved significantly in both groups, and there were no significant differences in results between the two groups, except for significantly better (P < 0.06) functional outcome in relation to daily activities in the instrumented group when neural decompression had been performed. The global patients' satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group (not significant). Fixation of instrumentation increased operation time, blood loss, and early reoperation rate significantly. Patients experienced only a few minor postoperative complications; none were major. Two infections appeared in the Cotrel-Dubousset group. Significant symptoms from misplacement of pedicle screws were seen in 4.8% of the instrumented patients. CONCLUSIONS: Lumbar posterolateral fusion with pedicle screw fixation increases the operation time, blood loss, and reoperation rate, and leads to a significant risk of nerve injury. The functional outcome improves significantly with high patient satisfaction, with or without instrumentation. No significant differences were observed between the two groups in functional outcome and fusion rate. The only gain in functional outcome from instrumentation was found in the daily activity category in patients with supplementary neural decompression. The results of this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

[Spinal fractures in adults in bob-sled accidents]. / Columnafrakturer hos voksne efter styrt på plasticbobslaede.

A case study of two adults who sustained severe burst fractures of the thoracolumbar spine (T12, L1) after trivial accidents using plastic sledges. In one case a transient conus medullaris lesion was encountered. The fractures were reduced indirectly by internal fixation as well as by direct anteposition of the fragments from the spinal canal after laminectomy. The fracture mechanism is probably a result of hyperflexion combined with very little shock absorbtion from this sledgetype. Plastic sledges seem particularly hazardous for adults.

Survivorship analysis of hemiarthroplasties.

From 1976 until 1988, 679 hemiarthroplasties were inserted for displaced femoral neck fractures. Two hundred two were of the Austin Moore design (one-piece, noncemented), 209 of the Christiansen design (trunion bearing, cemented), and 268 of the Hastings design (bipolar, cemented). Five years after the hemiarthroplasty, the cumulative proportion of prostheses surviving was 90%, declining to 85% after ten years. A survivorship analysis indicated that the cemented bipolar Hastings prosthesis and old age (75 years or older) were two variables associated with significantly less failures. The survivorship analysis did not indicate that the group differences were influenced by improvements in surgical techniques over time. Gender and social setting had no influence on the survival of prostheses. Cemented bipolar hemiarthroplasty should be considered as an alternative in the internal fixation of displaced femoral neck fractures in the elderly.

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.

Epidemiology of violence in a Danish municipality. Changes in the incidence during the 1980s.

A one-year prospective study of injuries caused by violence was performed at the two casualty wards and at the Institute of Forensic Medicine in Arhus, and the results were compared with those of a similar study done six years earlier. Whereas the population at risk increased by 4% to just over a quarter of a million, the number of cases increased by 14% to 1874 (p = 0.06) and the number of persons by 17% to 1726 (p = 0.01). The overall incidence increased for females from 3.0 to 3.7 per 1000 (maximum 7.4 per 1000 females 35-39 years old), and for males from 10.6 to 11.1 per 1000 (maximum 33.4 per 1000 males 15-19 years old). Statistically significant increase of age-specific incidence rates was only found among females 35-49 years old, where, however, also the largest frequency of repeated registrations was noted. As in the former investigation, almost three-fourths of male violence took place at bars and discotheques or on the street, usually associated with unknown person(s), whereas one-half of female violence occurred at home with the partner as the most frequent counterpart. Police recorded cases increased from 16 to 22% (p less than 0.05).

Epidemiology of violence in a Danish municipality. Changes in severity during the 1980s.

Between April 1987 and April 1988, all assault victims attending the two casualty wards and the Institute of Forensic Medicine in Arhus were registered, and an extensive questionnaire was completed by the casualty ward physician. These data were compared with the data from an analogous study undertaken six years earlier. A total of 1874 patients were victims of personal violence in 1987 compared to 1639 in 1981. The most common cause of injury was one or more blows from a fist and/or kicks (used in approximately 70% of all cases). The present study demonstrated an increasing use of firearms and assaults involving attempts to strangle the victim. Ninety-eight percent of the injuries were classified as no injury or AIS-grade 1-2 in both 1981 and 1987. The number of AIS-grade 2 injuries increased from 1981 to 1987 due to an increased number of facial injuries, but the number of homicides and AIS-grade 4-6 injuries decreased in the interval. Based on the present study, it is concluded that the severity of interpersonal violence did not increase in the Arhus area in the 1980s.

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.

Prevention of thromboembolism in 190 hip arthroplasties. Comparison of LMW heparin and placebo.

Prophylactic efficacy and safety of a low molecular weight (LMW) heparin against postoperative thromboembolic complications were investigated in a double-blind, randomized study. Totally, 210 consecutive patients undergoing total hip replacement were allocated to two groups. Patients in the heparin group received 50 IU anti-Xa per kilo body weight of Logiparin once daily, and patients in the placebo group received one daily injection of saline. Additional prophylaxis in all the patients was thigh-length compression stockings beginning on the day of the operation. Deep vein thrombosis was diagnosed by bilateral ascending phlebography between Days 8 and 10 after the operation. Twenty patients were excluded from the evaluation. Thirty of 93 patients in the heparin group compared with 45 of 97 patients in the placebo group suffered a thromboembolic complication during the study (P = 0.02). The postoperative blood loss and total number of blood transfusions in the heparin group were higher than in the placebo group. However, the observed differences were of no clinical importance. Adverse effects, including bleeding complications and wound hematomas, were observed in 13 heparin patients and 7 placebo patients (NS). One patient in each group died. Thrombo-prophylaxis with LMW heparin once daily was safe and more effective than the placebo in patients undergoing total hip replacement.

[Street violence in Arhus]. / Gadevold i Arhus.

As part of a one-year prospective investigation of all violent accidents in Arhus undertaken in the casualty departments and the Medicolegal Institute, the extent and severity of street violence were analysed and compared with violence in and near pubs. Street violence constituted 26% of all accidents due to violence and involved 1.3 persons per day. 75% were blameless and 68% of these were attacked outside the region where they lived. Violence in the street, in pubs and in the vicinity of pubs was concentrated in the centre of the city, in the evening and night hours, at weekends and involved young men. Street violence and violence in the vicinity of pubs differed from violence in pubs in that significantly more of the victims were blameless (approximately 75%), several persons were the perpetrators (approximately 40%) and blows and kicks were combined (approximately 15%). As assessed by the Abbreviated Injury Scale (AIS), the lesions sustained in street injury did not differ from those of violence in or near pubs: 86% were minor injuries, 11% moderate and none proved fatal. 75% of the victims could be treated completely in the casualty department or by the general practitioner or dentist. Street violence is concentrated to the middle of the city, at weekends and in the evening and night hours and is similar in many ways to violence in and near pubs. The authors consider that exposure to street violence is, to a great extent, connected with participation in night life of the city.

[Violence and women in Arhus. Changes in the 1980's]. / Vold og kvinder i Arhus. Aendring i 1980'erne.

As part of a one-year prospective investigation of accidents due to violence in Arhus carried out by the casualty departments and the Institute of Forensic Medicine in cooperation with the Arhus Police and the Crisis centre for female victims of violence, the fraction of violence which involved women was analysed. A total of 492 contacts were received from 424 women. The average age was 32 years. The home was the commonest site of violence with the husband as the commonest perpetrator of violence (192). In 98 cases the perpetrator was unknown. The majority had received blunt injuries (blows and/or kicks). The lesions frequently appeared to be limited from a therapeutic viewpoint. In 143 women, however, the lesions were potentially serious. Thirteen women were hospitalized and 60 were referred for treatment in other departments. Violence was commonest in the evening and night hours and there was a tendency to an increase towards the end of the week. The majority (279) stated that the episode was not their fault. The police were contacted in 25% of the cases. A total of 164 requests were made for access to the Crisis Centre by female victims of violence. Of these, 30 women had been seen by a doctor and 23 had previously been hospitalized. Compared with conditions five years previously, a considerable increase in the number of registered violent accidents to women was observed. On the other hand, no definite evidence was found that the nature of the violence to which they had been exposed had altered during the past five years.

Biological tolerance of Logiparin, a low molecular weight heparin used in patients undergoing total hip replacement.

Two hundred ten patients scheduled for THR were randomized into two groups. Group A (105 patients) received Logiparin (Novo-Nordisk, Denmark) 50 mg/kg body weight once daily, and group B (105 patients) received placebo once daily. Injections started 2 hr preoperatively and continued for 7 days. Blood samples were collected preoperatively before medication and 3 hr after last injection on the seventh postoperative day. Two hundred three patients completed the study: 103 in group A, 100 in group B. In group A there was a significantly higher increase in ASAT (p = 0.0006) and APH (p = 0.0137) compared with group B. Significantly more patients in group A showed an increase from normal preoperative values to pathological postoperative values in ASAT (p = 0.0012) and APH (p = 0.025) compared with group B. All changes were found to be reversible within 2 weeks of termination of drug treatment. Although no conclusion about the mechanism leading to the increase in ASAT and APH is possible from this data, there is very good suggestive evidence that the liver is influenced by this agent.

Locked nailing of comminuted and unstable fractures of the femur.

Forty comminuted or unstable fractures of the femoral shaft were treated by closed intramedullary reaming and locked nailing. Twenty-four fractures were severely comminuted, and the other 16, in the distal or proximal third of the shaft, were classified as unstable. At 12 to 30 months postoperatively all the fractures had healed. Three patients had lateral rotation deformity of 5 degrees to 10 degrees, three had shortening of 1 to 2 cm and two had lengthening of about 1 cm. There were no infections or delayed unions. Closed intramedullary locked nailing can provide stability in fractures of the femoral shaft, irrespective of the degree of comminution and the site of injury.