Introduction

Insufficient arthroscopic cuff tear reconstruction leading to massive osteoarthritis and irreparable rotator cuff tears might be salvaged by implantation of an inverted total shoulder prosthesis Delta in the elderly. However, despite the generally high success rate and satisfying clinical results of inverted total shoulder arthroplasty, this treatment option has potential complications. Therefore, the objective of this study was a prospective evaluation of the clinical and radiological outcome after a minimum of 2 years follow-up of patients undergoing inverted shoulder replacement with or without prior rotator cuff repair.

Background: Postoperative thromboses are among the most feared complications in orthopedic surgery, possibly causing life-threatening conditions in otherwise highly successful procedures such as total joint replacement. Body weight is an important risk factor for thromboses and is being used in algorithms to determine dosages in prophylaxis. However, weight patterns among orthopedic populations have changed considerably since the introduction of these algorithms, essentially shifting towards obesity. This study asks whether present-day obese patients are essential under-dosed and would benefit from higher than usual dosages of bemiparin sodium in the prophylaxis of postoperative thrombosis.

Patients and Methods: To ensure sufficient power a sample of 750 patients, allocated into two cohorts receiving either 3,500 IU or 5,00o IU bemiparin sodium were followed postoperatively for 6 weeks and blindly assessed for clinically symptomatic thrombotic events. Differences in rates of thrombotic events were modeled using mulitvariate Poisson regression including potential confounders severity of immobilisation, gender, exact weight, and age as covariates. A p-value of 5% was considered significant.

Results: Information on 723 patients for a total of 66.8 person-years was analysed per intention-to-treat. The adjusted incidence rate ratio was 0.35 (95%CI: 0.03 to 2.91). Thus there was not evidence for a difference in rates between groups. There was, however, a borderline significant association between rates and body weight, suggesting a potential benefit of higher dosages in even heavier patients. There were no complications due to higher dosages of bemiparin sodium.

Conclusion: We did not see a significant reduction of incidence rates of thromboses with higher dosages of bemiparin in this population. However, there was some evidence that higher dosages might prove beneficial as populations further gain weight.

Introduction: The skeleton is the most common location for metastases, with life-time prevalences of 15% and 70% during autopsies. The Vienna Bone and Soft Tissue Tumor Registry has been established in 1965 and is collecting data on primary and secondary malignancies of the musculoskeletal apparatus ever since. The objective of this study was to review the epidemiology and survival of patients undergoing spinal stabilization, including an analysis of trends over time.

Methods: Data on patients operated on between 1980 and 2007 were available from the Tumor registry. Information on location of metastases, number of metastases within and outside the spine, primary tumor, as well as complications and recurrences after treatment were extracted. Survival after surgery was assessed using the Kaplan-Meier method, adjusting for patient age by Lexis expansion. Furthermore, the dataset was expanded on calendar time to test changes in epidemiology and survival during the observed 28 years. The effect of the abovementioned variables on survival was assessed in a Cox regression model using patient age and calendar time as time frame.

Results: Data on 254 patients could be ed. The most common primary diagnoses were hypernephroma (26.4%), breast cancer (19.75), and lung cancer (12.2%), mostly metastasizing to thoracic and lumbosacral spine (40% both). 104 patients (47.9%) had multiple spinal and 41 (16.1%) other osseous non-spinal metastases. 14.6% had complications in the immediate postoperative follow-up, 4.3% suffered from recurrences postoperatively. Average survival after surgery was 0.9 years (95%CI 0.7 to 1.0) with an average patient age of 60.4 years (95%CI 58.8 to 62.0). In the regression model location of metastases (p=0.008), primary malignancy (p< 0.001), and recurrences (p=0.008) were associated with decreases in survival. There was no association between survival time and the decade during which patients were treated (p=0.157). However, there were significantly less complications in patients treated in later decades, demonstrating the patient’s benefit of being referred to a specialized centre (p=0.015).

Discussion: For our study, we are able to draw from experience of 28 years with stabilization due to spinal metastases. Analyzing the data from 254 patients we observed that spinal metastases stem from a similar pattern of primary malignancies. The average survival in our cohort was less than a year, with a very narrow confidence interval. While survival was not associated with later periods of follow-up, number of complications was, supporting the recommendation to refer cancer patients to specialized centers with appropriate experience. The external validity of our findings, however, is confined by the source of our patients, which comprises mostly central and eastern European patients, and few cases referred from more remote areas.

Introduction: Meta-analyses are an important instrument in orthopaedic surgery, not only to create clinical guidelines, but also because their findings are included in public health and health policy decision-making. Generally, meta-analyses of randomised controlled trials are considered as the highest level of evidence. However, with increasing numbers of meta-analyses, discordance and frank conflicts in results have been seen, which might lead to grave complications considering the aforementioned facts. The purpose of this study was to search for conflicting meta-analyses in orthopaedic surgery, i.e. such arriving at different conclusions despite following the same research question; to identify potential reasons for, and to assess the actual amount and significance of such differences.

Methods: We searched the online databases PubMed, EMBASE and the Cochrane Controlled Trial Register for orthopaedic meta-analyses and cross-referenced results within and across databases to identify meta-analyses focusing on the same subject. Meta-analyses were defined as conflicting if they arrived at different results despite studying the same populations.

To assess the significance of such difference we used Cochrane’s Q-test. To test the amount, thus clinical meaning, of differences we calculated the I2-index, the amount of difference beyond random chance. Since both these parameters depend on study size, we also calculated the “uncertainty interval” (UI), which, in accordance to the 95% confidence interval contains the true I2-index of the whole population.

Results: We were able to identify conflicting meta-analyses on graft choice in ACL reconstruction (n=7), the use of hyaluronic acid (n=5) and pulsed electromagnetic fields in osteoarthritis (n=2). Significant differences could only be shown among meta-analyses on hyaluronic acid (p< 0.001). The uncertainty intervals were 38.6% to 78.6% for hyaluronic acid, 0% to 41.1% for ACL and 0% to 99% for electromagnetic fields in osteoarthritis.

Discussion: There are conflicting meta-analyses in orthopaedic research, posing a threat to evidence-based treatments. It seems, however, that a considerable amount of conflict derives from differences in the interpretation of pooled results rather than from the results themselves. In summary, findings and interpretations of meta-analyses should be as critically scrutinized as in any other type of study and subjected to re-assessment if deemed necessary.

Introduction: Minimally invasive surgery (MIS) in total joint replacement is a heavily if not fiercely discussed issue in orthopaedic surgery. Proponents of such techniques report faster healing and mobilization and strikingly satisfied patients, whilst critics warn of devastating complications. Although a large number of randomised, controlled trials and other studies have been published, the field is still characterized by inconsistent results. This study asked whether there is, in the entirety of the published literature, evidence in favor of or against the use of MIS techniques in total joint replacement.

Methods: We conducted a systematic review of ran-domised, controlled trials in the online databases PubMed, EMBASE, and the Cochrane Controlled Trial Register, as well as by hand-searching relevant publications. Subsequently, we pooled data for the effect of minimally invasive surgery (MIS) separately in individual meta-analyses per joint. 95% confidence intervals (CI) were constructed for the pooled estimates of the endpoints duration of procedure, estimated blood loss, perioperative complication rate, outliers in component placement, postoperative scores, hospital stay, and incision length. For these endpoints, the 95%CIs, which include the true population effect with 95% confidence, were compared for areas of overlap among different joints, which would indicate a common, independent effect of MIS techniques. The distance from zero and the spread of these overlaps are used to infer statistical significance.

Results: Data on 1161 patients in 12 trials were available. We found common effects for all endpoints, with average overlap of 62.4% and 50.5%, respectively. The common effects for component position, blood loss, postoperative scores, and incision length were significantly different from zero. Their absolute values were rather small at 20 mL to 70 mL less blood loss and a difference in effect size of 0.03 to 0.35 on clinical scores. There was no indication of a difference in complication rates.

Discussion: We could show that there is evidence that MIS total joint replacement is an effective alternative to other treatments. There is no evidence of higher complication rates among 1161 operations. Those results that were significantly better in the MIS group, however, had only small absolute values, suggesting MIS as an alternative but not substitute for classical methods. The question remains if these values are clinically significant or could be increased to sufficient numbers even techniques are developed further. For none of the endpoints we could see better result in the standard technique than with MIS.

Introduction: There is a general trend and even demand of using evidence-based methods in the practice of medicine. Especially in orthopedic surgery, which is a specialty traditionally employing treatments with obvious effectiveness, evidence-based clinical decision-making has become a strong trend. Yet all evidence-based decisions are only as sound as the evidence they are based on. In other studies, we could show that only 1 in 3 controlled orthopaedic trial accounts for confounding, and that there is even conflict in the results of meta-analyses, which are supposed to produce the highest level of evidence. This study asked how high the quality of evidence in orthopaedic research really is, and, thus, whether it would be applicable in “evidence”-based orthopaedics.

Method: All 2006 controlled trials from orthopedic journals with high impact-factor are analyzed in a cross-sectional study. A score based on the CONSORT statement was used to assess study quality. This score assesses power analyses, prospectiveness, randomization, allocation concealment and observer blinding, intention-to-treat, and how losses during follow-up were addressed. We also assessed whether there was an association between the test score and variables such as area of research and participation of a researcher with methodological training. Finally we tested the inter-observer reliability of our test between an investigator with postgraduate training in biostatistics and epidemiology and an orthopaedic resident with no specific methodological training beyond medical school.

Results: The overall quality of 126 studies was moderate to high, with an average score of 3.4 ± 1.7. The most neglected parameters were power analysis, intention-to-treat, and concealment. There were significant differences in results by area of research (p=0.022). The highest values were seen in oncology (4.6 ± 1.4) and osteoarthritis (4.4 ± 1.8), the lowest in traumatology (2.9 ± 1.3). The participation of a methodologically trained investigator increases study quality significantly (p=0.002). There is no difference in study quality whether there is statistically significant result or not (p=0.497). There was a 81.2% agreement, suggesting that study quality can be judged regardless of “specific training”.

Conclusion: We found good to high values for orthopaedic evidence on our scale, suggest high validity and applciability. We also saw that this instrument can be used without methodological training. However, there seems to be neglect of some important study features like power analyses, intention-to-treat, and concealment. Heightened awareness of this problem will help to increase the quality of orthopaedic evidence, and thus the clinical applicability of evidence-based orthopaedics.