Introduction
Perioprosthetic infections are very rare; however, due to the resulting high morbidity rate, endoprosthesis (EP) complications require very complex therapy by an interdisciplinary team, and they often have an unsatisfying prognosis [
1]. Therefore, the prevention of such infections is a mandatory aim in pre- and postoperative care. As potential sources of infection, various bacterial foci may be able to cause haematogenous spread, thus leading to EP infection [
2]. As one of these outcomes, the oral cavity and related inflammatory diseases have been repeatedly mentioned as being causes of EP infections; however, results of studies regarding this scenario have been controversial [
3‐
5].
Although clear evidence for oral disease-induced EP infections remains unclear, several implications for dental care in patients prior to EP have been discussed. For example, dental clearance prior to EP surgery, such as the rehabilitation or removal of all potential infectious foci in the mouth, teeth, periodontium and jaws, has been mentioned as being highly relevant [
6,
7]. Moreover, appropriate dental maintenance care, including prevention-oriented therapy via regular dental consultations and preventive measures to reduce the risk for de novo development of potential oral foci, can be regarded as a major task to reduce the risk of EP infections [
6,
7]. In this context, the potential usage of antibiotic prophylaxis for dental interventions is controversial; additionally, recent literature clearly does not recommend antibiotic prophylaxis for patients with EP prior to dental measures [
7,
8]. However, antibiotic prophylaxis may be reasonable in patients who are selected as being at-risk for EP infection [
6]. Accordingly, uniform guidelines are still missing. Furthermore, regardless of the existing controversies, all of the abovementioned considerations require the following two circumstances: (I) patients need to be informed, should perform oral hygiene as appropriately as possible and should visit the dentist in a control/prevention-oriented manner; and (II) EP centres and dentists should work together and communicate to ensure appropriate dental care of the patients. For this scenario, referral of the patients for dental consultation should be applied, which has been previously reported as a concept [
9]. Until now, these two issues have remained unclear. In particular, there is no information on whether the EP centres are aware of oral health concerns and whether they cooperate with dentists.
Therefore, the current questionnaire-based study had two aims. First, oral behaviour, oral hygiene, oral complaints and information on oral health (as well as its possible influence on EP) should be examined in patients prior to EP in one orthopaedic (endoprosthetic) centre in Germany. Second, German orthopaedic surgeons should be evaluated regarding their handling of oral health topics, potential patient referrals and available concepts to ensure appropriate dental care for the patients. To investigate these aims, two surveys were administered to patients and orthopaedic surgeons. It was hypothesised that patients are not aware of the potential importance of oral health for their EP; thus, they will not exhibit increased oral health behaviour. The second hypothesis was that EP centres rarely refer patients to a dentist and do not have a dental care concept for the respective patients prior to EP.
Discussion
Only one-third of the patients prior to EP were informed about the potential relationship between EP and oral health. Regular professional tooth cleaning and interdental cleaning were comparably rare, thus indicating deficits in oral hygiene behaviour of the patients (especially in home care for interdental cleaning, as well as professional care involving regular professional tooth cleaning). However, information about oral hygiene and EP was associated with regular tooth cleaning. Although orthopaedic centres stated that they were familiar with the relationship between oral health and EP, dental collaboration and/or referral was not a common practice. Although several minor associations between the characteristics of the centre and their handling of dental health issues were confirmed, no clear difference was observed between different types of EP centres.
Based on the potential relationship between oral inflammation and EP infections, one may have expected that the oral health behaviour of patients prior to EP should be increased. However, the current study demonstrated that there is a lack of information on the oral hygiene behaviour of patients. In this regard, patients in this EP study cohort showed approximate equal rates of oral health behaviours compared to a representative German population of the Fifth German Oral Health Study (DMS V) at a similar age (65–74 years). Likewise, approximately one-third of participants used an electric toothbrush (EP: 35.5%, DMS V: 31.3%), as well as interdental cleaning (EP: 29.1% vs. DMS V: 28.6%). Although almost half (48.3%) of all of the patients prior to EP received regular professional tooth cleaning, this scenario only applied to 30% of the DMS V population [
14].
Moreover, other patient groups exhibited deficits in oral hygiene and oral health behaviour; in particular, severely diseased patients showed insufficient oral behaviour, including patients with heart diseases, dialysis or organ transplantation [
11,
15,
16]. Therefore, it has been concluded that patients with severe general diseases often exhibit a decreased perception of oral conditions (
response shift) [
17]. Patients prior to EP regularly suffer from pain in the respective joints [
18]. Moreover, the impaired quality of life and pain may displace other health concerns, such as oral health. Therefore, patients foster neither their oral hygiene nor their prevention-oriented dental behaviour. This highlights the potential necessity of appropriate information and motivation of patients for oral health issues. When compared to previous findings of this working group, whereby one-third of patients prior to EP surgery had at least one potential oral focus [
9], an improvement in oral behaviour would be highly recommended. As the results demonstrated, the minority of patients were informed about oral health and EP. Therefore, only information on the importance of oral hygiene for EP led to a higher utilisation of professional tooth cleaning (Table
4). Accordingly, more patient-oriented forms of information and sensibilisation may be needed, such as the application of visual metaphors or comprehensive information based on flyers, as has been previously performed [
19]. Therefore, when regarding the average age of the patients, the EP study population also included elderly patients who may have been geriatric. In this context, the age-related increasing risk of (perioperative) inflammatory diseases due to the less efficiently working immune system (known as “immune senescence”) must be considered [
20].
When considering the insufficient information and the oral behaviour of patients, the results of orthopaedic clinics are of considerable interest. Therefore, we observed that EP surgeons are aware of the importance of oral health and perceive its importance as being high (see Fig.
1); however, they refer only half of patients to a dentist, whereas the minority have dental contacts (Table
6). This scenario is similar to a small previous survey in 2011, although the previous study observed that only 3% of orthopaedic clinics had dental contacts [
12]. Although evidence is limited, there appears to be a lack of cooperation between orthopaedic surgeons and dentists; this result has already been observed in the context of osteoporosis treatment and risk of osteonecrosis of the jaw [
21], which is a far more evident and common topic than oral health-induced EP infections. Different views between dentists and other medical professionals, such as general physicians, have also been previously demonstrated [
13]. Based on the separate education of dentists and physicians in Germany, divergent expectations and insufficient knowledge have appeared to result in a lack of collaboration [
22,
23]. Therefore, this problem appears to require changes in education (undergraduate and postgraduate) to create awareness of the respective other fields. Another topic of the survey was the need for antibiotic prophylaxis for dental interventions in patients with EP. Seventy-six percent of EP centres stated of informing their patients on the necessity of antibiotic prophylaxis for dental interventions after EP insertion. This rate is considerably greater than that reported in a previous study (55%) [
12]. However, current literature and international recommendations no longer recommend antibiotic prophylaxis for these patients [
7,
8]. In contrast, recent clinical data suggest that dental rehabilitation and maintenance would be most appropriate to support EP health [
7], which necessitates an improvement in the collaboration between dentists and orthopaedic surgeons. As Table
2 illustrates, only one-quarter of patients informed their dentist about the planned EP. Therefore, the main task in informing/educating patients appears to be focused on orthopaedic surgeons, who should refer the patients to a dentist prior to EP surgery.
Additionally, the current study examined the potential associations between the characteristics of the centre and their handling with oral health concerns. Although the number of inhabitants of the city in which the centre was located had an incongruent association with the centres’ care of oral health issues, another finding was of potential interest. Specifically, University Medical Centres had significantly more frequent dental contacts; this may be explained by the structure of university clinics, which often also have a dental faculty of dentistry, thus facilitating interdisciplinary collaboration. As shown in a previous study conducted within a university setting, this type of collaborative/cooperative partnership is a working but elaborative relationship [
9]. Accordingly, in addition to improved interdisciplinary collaboration, easily applicable and practical solutions are needed to simplify the transfer of such concepts into broad practice.
This current questionnaire-based study applied two comprehensive surveys to both patients and orthopaedic surgeons, whereby a reasonable cohort of each group could be included. To the authors’ knowledge, these represent the largest surveys for both patients prior to EP and orthopaedic centres. The fact that centres throughout Germany were included ensured that the survey was quite representative. However, the study was restricted to Germany; therefore, the generalizability of the results to other countries with distinct health systems is limited. Additionally, patients were only surveyed in one centre. Moreover, the perspective of respective dentists is still missing. A similar questionnaire for the related dentists would have provided interesting information about the “other side” of the cooperation. Furthermore, the response rate of orthopaedic clinics was quite low but comparable with previous research [
12]. This may have also limited the results, as the surgeons answering the questionnaire may have a certain interest or motivation in the topic of dental care. It can be presumed that a survey including all centres would have demonstrated an even worse situation.
In addition, EP patients are often seniors with specific geriatric problems. For this reason, it may be of interest to determine which centres provide an orthogeriatric specialty and consequently focus more on oral health than nonorthogeriatric centres. This point was not mentioned in the current survey of EP centres. Altogether, the current survey provides novel information and potential implications to improve the interdisciplinary care of patients prior to EP.
In summary, based on the current scientific evidence, a recommendation for dental examination and focal restoration (intervention) prior to EP can be suggested to prevent oral health statuses from becoming a potential risk for possible EP infections [
7,
24]. Nevertheless, for practical implementation and a scientific outlook, interdisciplinary collaboration between orthopaedic clinicians and dentists is important and should be considered in future research. Further research efforts are required to prove causality between oral health and EP infections, including (1) evidence that dental visits and (as needed) focused rehabilitation (intervention) prior to EP reduces the number of infections compared to missing dental visits prior to EP, (2) the detection of oral pathogenic bacteria (both orally and on EP) at infected EP and (3) comparison with another patient group (under risk) that is particularly susceptible to oral-related EP infections [
7,
24].
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