Objective To compare the inter-evaluator reliability of the Barbary macaque and the expert team of surgeons in the treatment options and predictive outcomes of proximal humeral fractures.
Design uncontrolled, blind, comparative behavior analysis.
Set Germany and the United States.
Participants included 10 blind specialists from Germany and the United States in the field of orthopedic trauma surgery (Homo chirurgicus accidentus) with a special focus on upper limb surgery, and 5 Barbary macaques (Macaca sylvanus) from a semi-free range enclosure.
The main outcome measures the reliability of agreement between raters evaluated by Fleiss' ĸ.
Results Compared with experts, Barbary macaques seem to have poorer reliability among evaluators in terms of treatment options (non-surgical and surgical). However, for the elderly group most commonly affected by proximal humeral fractures, their performance in selection is similar to Experts choose similar treatment methods and surgical methods. The consistency of the prediction results among the macaques is very poor, and the agreement among the experts is very small. All experts almost always predict the result incorrectly and tend to underestimate it. Although only 4 out of the 90 experts’ predictions (4.4%) were correct, 13 out of the 45 macaques’ predictions (28.9%) were correct.
Conclusion There is a lack of consensus on the treatment and expected results of proximal humeral fractures even outside of humans. Although Barbary macaques tend to predict clinical outcomes more accurately, their reliability in helping surgeons make consistent decisions is limited. In the future, high-quality research is needed to guide surgeons in making decisions about the best treatment for this common injury.
Fractures of the proximal humerus are a common injury, accounting for approximately 6% of all adult fractures. 1 Approximately 70% of these fractures occur in patients over 60 years of age, and the highest reported incidence is in people 80 years of age or older. In the past few decades, the incidence of proximal humeral fractures has been increasing due to the aging of the population and the associated osteoporosis and increased low energy at standing height. In the United States, the incidence of proximal humeral fractures is about 60 per 100,000 people, but among people 65 years of age or older, the incidence is four times higher, at 253 per 100,000 people. In Finland, the incidence of proximal humeral fractures tripled between 1970 and 2002, reaching 105 per 100,000 people aged 60 or over. 234 As a result, the management of proximal humeral fractures in the healthcare system will increase. 5
Although it is well known that most proximal humeral fractures (nearly 75%) can be treated non-surgically with acceptable functional results, but with the advancement in the field of osteosynthetic implants, such as locking nails, steel plates, and prosthetic shoulder replacements Surgery has become popular. 4 In some institutions, the rate of surgical treatment of patients is higher than 25%, resulting in large differences in the management of this common injury worldwide. 6
In a review of a large sample of data from U.S. Medicare, Bell and co-authors found that the number of surgical operations for proximal humeral fractures increased significantly, but the incidence did not increase correspondingly during the study period. In addition, the number of surgical operations for proximal humeral fractures was significant. To increase the surgical rate, ranging from 0% to 68%. 7 The heterogeneity of this treatment is in the absence of scientific consensus on the best treatment for these fractures. 4 The latest Cochrane review shows that non-surgical treatments may have similar functional surgical results, with lower risks of complications and reoperation. However, the current randomized controlled trials do not have enough evidence for different non-surgical, surgical treatments of these fractures. Or provide information for decision-making between rehabilitation interventions. 8910
But there is still hope. In the depths of the Thuringia Basin in Germany, between the mottled sandstone hills of Windleite and the shell limestone formations of Hainleite, surrounded by the gurgling of the Wernröder stream, the Barbary macaque (Macaca sylvanus) lives in the vast beech forests of Germany And roam one of the largest semi-free range fences in Europe. In addition to humans, the Barbary macaque is the only free-living primate in Europe. In addition to elderly patients with proximal humeral fractures, it is also one of the most endangered species in the world (Figure 1).
According to the International Union for Conservation of Nature, the protection status of proximal humeral fractures and Barbary macaques. 11 This figure shows the slight displacement of the proximal humerus fracture according to the most commonly used Neer classification. 12 A 70-year-old woman received intramedullary nail treatment at a trauma center in Germany in 2019, possibly due to its superior biomechanics to extramedullary implants. 13 Only three months later, reverse shoulder arthroplasty was performed, probably due to its better biomechanics than intramedullary nails
Due to the lack of evidence-based guidelines and expert consensus is considered poor, due to its impartiality and ability to place itself in the same threatening position as patients with proximal humeral fractures, this species may be promising for future decision-making processes. The purpose of this behavioral analysis is to investigate the reliability of the Barbary macaque and the expert team of surgeons in the treatment selection and outcome prediction of proximal humeral fractures, and to determine the degree of consensus on the treatment of this common problem. Hurt.
This behavioral analysis is based on the ethical standards of the 1964 Declaration of Helsinki, which was updated in 2004. No animal is forced to participate or is misused, abused or damaged in any way. However, after reading this analysis, some people may feel that they are so.
We identified independent experts in the field of orthopedic trauma surgery from Germany and the United States, with special attention to upper limb surgery, and invited them to participate in an anonymous online survey via email (SoSci Survey GmbH, Munich, Germany). The survey included nine case reports of acute proximal humeral fractures. The case display includes X-rays and reconstructed three-dimensional computed tomography (CT) images, patient demographic information, information about secondary diseases, and general health conditions before injury, using the three-level version of EuroQoL's five-dimensional instrument (EQ) The format is -5D-3L; 14 supplementary materials). All cases were randomly selected from a prospective and observational registry study (Hannover Humerus Registry, NCT03060876). Two independent research nurses conducted a 12-month clinical and radiological follow-up of all cases.
The Hannover Humerus Registry is a CT-based prospective single-center registration study for super-regional level 1 trauma centers to investigate the healing process of proximal humerus and humeral shaft fractures. We informed all experts of the intention of this analysis. They are only unaware of the actual treatment procedures and results. In addition to the detailed information and professional work experience of the expert members, their answers to the following questions and the corresponding answer options are also evaluated:
Which treatment would you recommend?
If you must have surgery, which surgery would you recommend?
Answer: Locking plate, cement-enhanced locking plate, intramedullary nail, half joint replacement, reverse shoulder arthroplasty, allograft enhanced locking plate or others.
After one year of conservative treatment, what kind of results do you expect (constant score 15 adjusted for age and gender)?
Answer: Less than or equal to 59, 60-69, 70-79, 80-89 or 90-100, out of 100 points.
Similarly, in the winter of January 2020, in one of the largest semi-free range pens in Europe (Affenwald Straußberg, Sonderhausen, Thuringia, Germany), the behavior of Barbary macaques was evaluated for the same 9 cases and questions . Excluded to ensure the anonymity of participating macaques. The web-based case presentation was printed as a 29.7 × 42 cm color poster, and the relevant and the above three questions were placed in the outer shell in succession using a customer stopper from a local ice cream supplier (Figure 2). With the help of internationally recognized and validated scoring scales, including disposable cellulose kidney discs and hierarchical pictograms, we observed the behavior of rhesus monkeys (Figure 2). Each kidney disc represents one of the possible reactions mentioned above. Equal amounts of Mediterranean raisins and peanuts (Nutwork GmbH, Hamburg, Germany) and California walnuts (Märsch Importhandel GmbH, Ulm, Germany) played a role in environmental enrichment and were placed in a kidney petri dish. Grabbing the kidney disc for the first time was defined as a treatment or outcome choice, and noticed this behavior. For the second question, any non-response in the macaque is defined as the response option "something else". In addition, macaques that did not fully respond to all cases and those with obvious serious conflicts of interest were excluded from the assessment (Figure 3).
The case report shows the condition of the verified scoring scale for Question 2 and Question 3 on the customer stopper of the local ice cream supplier in the fence and the analysis on the handling procedures and expected results. The two-piece scoring scale of question 1 and its two response options (non-surgical or surgical) are not shown because it cannot be kept intact from the macaque and cannot be followed up
A veteran macaque with obviously serious conflicts of interest is favoring one of its inferior subjects
Since this behavioral analysis is carried out voluntarily by macaques in their familiar enclosures under uncontrolled conditions, it is impossible to calculate the number of complete responses in advance. Therefore, it is necessary to analyze the macaques first, and then analyze the experts, to get a group of roughly the same size. For this reason, after receiving a considerable number of responses, the web-based survey was closed to experts.
In order to assess the reliability of the agreement among the raters, Fleiss's ĸ was determined. We use the benchmark scale developed by Landis and Koch to explain the consistency of Fleiss's ĸ value, as shown in Figure 4.16. SPSS 25 (IBM, Armonk, NY) was used in the analysis.
According to Landis and Koch's interpretation consistency benchmark scale, use Fleiss's ĸ value to evaluate
M sylvanus (Figure 5), also known as Barbary macaque or commonly known as maggot, is the only native primate living in Europe and the only macaque species found outside of Asia. 11 This species can live in a wide range of habitats, but prefers high-altitude forests and can also be found in coastal bushes and rocky slopes. As the habitat of Barbary macaques is threatened by human activities, their habitat availability and population have been greatly reduced in recent decades. 11 Therefore, macaques are listed as endangered species by the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. 11
Homo chirurgicusaccidentus and Macaca sylvanus in the scientific discourse on the principle of proximal humeral fractures
Barbary macaques are sociable and live in mixed gender groups, ranging in size from 13 to 80. Both sexes have their own hierarchy, and female Barbary macaques are strictly classified according to the matrilineal system. 171819 Their diet mainly consists of plant foods such as leaves, fruits and seeds, but they also like insects and mushrooms. 1719
H chirurgicusaccidentus (Figure 5), also known as orthopedic trauma surgeon or commonly known as cattle, 20 is a type of surgeon that is unique because of its wide distribution around the world. Although it can live in a wide range of habitats, it often appears in large medical centers in urban areas.
Sometimes, there are confrontational tensions between this species and other species, such as anesthesiologists, anesthesia nurses, anesthesia nurse assistants, and some orthopedic trauma surgeons who recommend non-surgical treatment, but these territorial conflicts are usually resolved without physical harm , But on the intellectual level. 20 Because of his extreme work spirit, his social and cultural ability and mating behavior are unknown. Both are the subject of in-depth research at present.
H chirurgicusaccidentus is active at night, so it is moody during most of the day, forming a group of equally moody men who are patriarchal and their rank is determined by the direct lineage or personal preference of the leader. Its diet mainly includes fractures, damaged cartilage, infected soft tissues and broken prostheses, but it also prefers profitable elective outpatient surgery.
The patient’s clinical and imaging records came from an observational registration study (Hanover Humerus Registry, NCT03060876) for investigation, and we thank them for their records. We did not involve patients in the design or analysis of the data.
Ten independent experts in the field of orthopedic trauma surgery from Germany and the United States pay special attention to upper limb surgery. The response rate of American experts is higher than that of Germany (5/10 v 5/20). Only 5 out of 22 macaques had a complete response to all cases, possibly because of fear of reputation damage. The responses of those who did not respond among experts ranged from diplomatic German "interesting ideas, but I'm going out, sorry" to an enthusiastic American "what my alma mater and former colleagues are now working on is crazy."
Figure 6 provides detailed information on the professional qualifications of experts. The professional qualifications or membership qualifications of rhesus monkeys are still uncertain, but it is clear that all of them have been trained in picking nostrils and removing lice from each other.
Professional qualifications of experts. All experts from the United States are members of the American Academy of Orthopaedic Surgeons (AAOS). All experts from Germany are members of the German Society of Shoulder and Elbow Surgery (DVSE), except for one, they are also members of the European Society of Shoulder and Elbow Surgery (SECEC-ESSSE). An expert is also a member of the American Shoulder and Elbow Surgeons (ASES). The icon is designed using free resources from Flaticon.com
Among experts, surgical treatment is the preferred treatment (51 out of 90 options), but macaques more often choose non-surgical treatment (25 out of 45 options). Although there are significant differences between the two different countries (Figure 7, Figure 8, and Figure 9), the overall agreement among experts on this choice is moderate, and the agreement between macaques is poor.
The inter-rater reliability of the species analyzed for the recommended treatment (non-surgical v surgical) is evaluated by Fleiss' ĸ
Conditional probability of recommending surgery
According to Question 1 and Question 2, select the number of recommended treatments and preferred surgical procedures respectively. The choices of experts and macaques are indicated by blue and red numbers, respectively. The icon is designed using free resources from Flaticon.com
In a post-event subgroup analysis of cases by patient age, for patients over 65 years of age, the agreement among experts on treatment options and surgical procedures was as poor as that of rhesus monkeys, while for 65-year-old patients, there was only slight agreement. Consistency or less (Figure 7 and Figure 10). Significant differences between countries have again appeared.
It is recommended that the inter-rater reliability of the species analyzed in surgery is evaluated by Fleiss' ĸ
Although American experts have reached a consensus on non-surgical treatment for patients over 65 years of age, the opinions of German experts are very poor. 4 out of 15 people (26.7%) tend to choose surgical treatment (Figure 7).
In the nine cases presented, all patients actually received non-surgical treatment, and the clinical results were excellent. The consistency of the results prediction between the macaques is poor, and the agreement between the experts is low (Figure 11). All experts almost always predict the result incorrectly and tend to underestimate it. Although only 4 of the 90 experts’ predictions (4.4%) were correct, 13 of the 45 macaques’ predictions (28.9%) were correct (Figure 12). Figure 9 provides detailed information on the selection of treatment methods and preferred surgical procedures by experts and rhesus monkeys.
Use Fleiss' ĸ to assess the inter-rater reliability of non-surgical treatment outcome predictions for the analyzed species
According to Question 3, the number of predictions for constant scores is adjusted according to age and gender and the actual results after one year of non-surgical treatment. *All patients received non-surgical treatment. The score is given as a score out of 100 points. The choices of experts and macaques are indicated by blue and red numbers respectively
This study investigated the inter-rater reliability of Barbary macaques and compared them with a panel of experts to manage and predict the clinical outcome of proximal humeral fractures. Compared with experts, Barbary macaques seem to be less reliable among evaluators in terms of treatment options (non-surgical and surgical), but their performance is similar to those most commonly affected by the humerus in terms of choice of treatment (non-surgical and surgical). Experts in the elderly group affected by end fractures choose similar treatment and surgical methods. These findings highlight the continuing controversy and lack of expert consensus regarding the best treatment for these fractures even outside the human species. 4621
Surgical treatment of proximal humeral fractures is associated with a complication rate of up to 49% and a reoperation rate of 14%. Increasing evidence from randomized controlled trials and meta-analysis shows similar results between surgical and non-surgical treatment of proximal humeral fractures, which question the surgical treatment of such fractures in patients older than 65.562122. A recent Cochrane review showed that during one to two years of follow-up, there were no clinically important differences between surgical and non-surgical treatment of proximal humeral fractures in terms of functional outcomes and quality of life. 816
Nevertheless, surgical treatment of this type of injury has been increasingly used in the past two decades. 5 Ironically, for the relevant age group over 65, the appraisers of these two species are also in poor agreement.
The significant differences between the two countries should be considered in the context of published national treatment trends. According to the analysis of the national inpatient database, the proportion of proximal humeral fractures undergoing surgical treatment in the United States increased by 6% between 2004 and 2012, but non-surgical treatment is still the most common treatment for 59% of patients. 23 On the contrary, according to a recent trend analysis of data from the German Federal Statistical Office, surgical operations in Germany increased by 39% from 2007 to 2016, and about 68.9% of operations were performed on elderly patients. twenty four
Locking plate fixation is the most commonly used surgery in all age groups, although compared with non-surgical hospitalization, it has been identified as an independent risk factor for hospital adverse events and mortality in patients over 65 years of age. 924 This risk is even higher. From the perspective of health economics, as previous epidemiology and cost analysis have shown, shoulder fractures have greatly contributed to the increase in the cost of upper limb fracture treatment. 5
Our research has some limitations that should be considered. Although it is a promising observation that rhesus monkeys choose non-surgical treatment more often than experts, their consensus on the best treatment has been poor. Unfortunately, the system's confounding behavior was seen throughout the research process. Some advanced primates with obvious serious conflicts of interest tend to favor responders in the selection process (Figure 3). We believe that this may adversely affect the results of these responders. Without this destructive factor, their consistency and predictability of results would be much better. Since this behavioral analysis was carried out voluntarily by macaques in their familiar enclosures under uncontrolled conditions, any attempts to prevent or minimize this occurrence were omitted. We chose to conduct this analysis in winter to avoid public access and ensure the anonymity of participating macaques; however, this choice may be bad because the author does not know that the conflict of interest between Barbary macaques started in November and lasted until March 3. Seasonal events of the month. 25
Self-reported conflicts of interest are also common among orthopedic trauma surgeons, and they are well known to affect the reported results. 26 The remarkable findings that all experts almost always underestimate and predict the outcome of non-surgical treatment of proximal humeral fractures indicate the possibility of interference among alleged independent experts. However, it is unclear whether, to what extent, and how the experts reviewed here were affected, as the self-disclosure only mentions detailed information about scientific members and professional work experience.
In addition, compared with 10 experts, there are only 5 rhesus monkeys in small numbers, which should be regarded as a limitation when explaining the overall inter-evaluator agreement between these two species.
In addition, in retrospect, a mixture of Mediterranean sultanas, peanuts, and California walnuts was an unfavorable choice for the author as an environmental enrichment. Unfortunately, a significant difference in the popularity of these snacks can be observed in the above order. This difference leads to a certain degree of dependent choice, when the kidney plate is not immediately refilled equally.
This form of selection bias must be regarded as the main methodological weakness. The author recommends California walnuts as the single food for future behavior analysis.
Even outside of humans, there is still a lack of consensus on the treatment and expected results of proximal humeral fractures. Although Barbary macaques tend to predict clinical outcomes more accurately, their reliability in helping surgeons make consistent decisions is limited. In the future, high-quality research is needed to guide surgeons in making decisions about the best treatment for this common injury.
To date, no consensus has been reached on the best treatment for proximal humeral fractures
There is increasing evidence that non-surgical treatment may have functional outcomes similar to surgical treatment, but the risk of complications and reoperation is lower
Lack of evidence-based guidelines to provide information for decision-making between different interventions, and expert consensus is considered poor
There is a lack of consensus on the treatment and expected results of proximal humeral fractures, even beyond the human species
High-quality research is needed in the future to guide surgeons in making decisions about the best treatment for this common injury
We thank Silvio Dietzel, a park ranger in Affenwald Straußberg (Sundhausen, Thuringia, Germany) and supervisor of this analysis, for his support of this research and non-commercial funding in the form of California walnuts.
Contributor: SR designed, implemented and wrote this analysis. BW conducted a statistical analysis. DZ, NH and CK determined and contacted experts to investigate. AH assisted in behavioral analysis and edited the manuscript. SR is the guarantor. The corresponding author certifies that all the listed authors meet the author criteria, and no other authors who meet the criteria are omitted.
Funding: Funding has not yet been obtained.
Competitive interest: All authors have completed the ICMJE uniform disclosure form on www.icmje.org/coi_disclosure.pdf and declared that the submitted works are not supported by any organization; and those who may be interested in the submitted work in the past three years Any organization has no financial relationship; there are no other relationships or activities that may affect the submitted work.
Patient consent: The manuscript contains images or information that may identify the patient. A signed consent form has been obtained.
Ethical approval: The analysis was performed in accordance with the ethical standards of the 1964 Declaration of Helsinki, which was updated in 2004. No animal is forced to participate or is misused, abused or damaged in any way. The behavioral analysis of Barbary macaques under uncontrolled conditions in their familiar enclosures was conducted under the supervision of responsible park rangers. The local ethics committee of the Hannover Medical School is required to comment on this behavioral analysis, but it does not assume responsibility for such satirical analysis (Supplementary material).
Data sharing: The complete data set can be obtained from the corresponding author sam.r@hotmail.de.
The guarantor of the manuscript confirms that the manuscript is an honest, accurate, and transparent description of the reported research; no important aspects of the research are omitted; and any differences from the planned research have been explained.
Dissemination to participants and relevant patients and the public community: In order to disseminate the results to the scientific community, it is planned to submit this topic to the Science-Slam event of the German Orthopedics and Traumatological Surgery Annual Conference (DKOU) in October 2021. In addition, if the article is published, We plan to use our institution website (https://www.mhh-unfallchirurgie.de/) and related attachments website (https://www.affenwald.info/) in order to provide patients and patients in a transparent and easy-to-understand manner. Non-experts disseminate results and information.
Provenance and peer review: not commissioned; external peer review.
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