Do Spanish surgeons trust hip stabilizing devices to prevent prosthetic dislocation?

Abstract

Introduction

One of the most common complications that can occur after total hip arthroplasty (THA) is dislocation. Prosthetic dislocation is described as one of the main causes of revision surgery. After a first episode most studies conclude that conservative treatment is acceptable. However, there is no consensus on a standardised treatment to help prevent further episodes. The goal of our study was to describe the preferences and reliance in clinical practice of hip-stabilizing devices among Spanish hip surgeons. It was hypothesized that no clear consensus exists among Spanish hip surgeons regarding the use of anti-dislocation devices.

Material and methodology

The survey was conducted to assess use of orthopaedic immobilisations. A total of eighty-three hip surgeons from hospitals in Spain responded about the volume of THA surgeries, the incidence of dislocation and the use of orthopaedic immobilisation devices after an episode of dislocation.

Results

There were 46% of surgeons who came from medium volume hospitals. The majority were senior surgeons. Up to 42% of the participants did not use any immobilization after the episode. The survey showed some variability among those who used some kind of immobilization orthosis regarding length of immobilization (from less than 2 weeks (14.6%) to more than 6 weeks (15.9%), as well as preference for different types of devices. We found no consensus on the use and trust of the device, for example 33% of surgeons who believed the orthosis ineffective affirmed they continued to use them in their clinical practice.

Conclusions

There is no consensus on the use of hip stabilizing devices. The survey reveals a very heterogeneous, surgeon and center-dependent use of orthopaedic devices.

Resumen

Introducción

Una de las complicaciones más comunes tras una artroplastia total de cadera (ATC) es la luxación, considerada una de las principales causas de cirugía de revisión. Actualmente no existe consenso sobre qué tratamiento es mejor para prevenir episodios de luxación. El objetivo de nuestro estudio es describir las preferencias del tipo de dispositivo estabilizante de cadera y la confianza que generan en la práctica clínica entre los cirujanos españoles de cadera. La hipótesis planteada fue que no existe homogeneidad en el uso de dispositivos estabilizadores de cadera entre los cirujanos españoles de cadera.

Material y métodos

Se realizó una encuesta para evaluar el uso de inmovilizaciones ortopédicas. Un total de 83 cirujanos de cadera respondieron sobre el volumen de cirugías de ATC, la incidencia de luxaciones y el uso de dispositivos de inmovilización ortopédica tras un episodio de luxación.

Resultados

El 46% de los cirujanos procedían de hospitales con un volumen medio de pacientes. La mayoría eran cirujanos experimentados. Hasta un 42% de los participantes no utilizaron ningún tipo de inmovilización tras el episodio. La encuesta mostró variabilidad en cuanto a la duración de la inmovilización, desde menos de 2 semanas (14,6%), hasta más de 6 semanas (15,9%), así como la preferencia por diferentes tipos de dispositivos. No hubo consenso sobre el uso y la confianza en el dispositivo; el 33% de los cirujanos que consideraban la órtesis ineficaz afirmaron que seguían utilizándola en su práctica clínica.

Conclusiones

No existe consenso sobre el uso de dispositivos estabilizadores de cadera. La encuesta revela un uso muy heterogéneo de dispositivos ortopédicos, que depende del cirujano y del centro.

Introduction

Total hip arthroplasty (THA) is one of the most successful procedures in the field of orthopaedic and trauma surgery,^1,2 with excellent results and a low complication rate. However, dislocation is a serious and difficult-to-manage complication.^3,4

Prosthetic dislocation is associated with multiple variables, such as soft tissue stability, which may be reduced in cases of muscle atrophy or abnormal tone due to advanced age or concomitant neurological diseases.¹ In addition, there are technical variables such as inadequate rehabilitation^2,5 or factors related to the surgical technique, such as improper implant placement or inadequate soft tissue tension.^1,3,6 Wera et al.,⁷ described six possible aetiologies to classify prosthetic instability: malposition of the acetabular component; malposition of the femoral component; abductor mechanism deficiency; impingement; late wear, and unresolved aetiology. Among these, the most frequently described are acetabular malposition and abductor mechanism deficiency, considered determining factors in the occurrence of dislocation after total hip replacement (THR). All these factors must be considered in the analysis of a prosthetic hip dislocation.

Dislocation rates of primary hip prostheses have been reported to range from .2% to 10%. During the first year, the risk is considered to be 2%. After revision THR surgery, the risk increases to between 9% and 28%, depending on patient characteristics, the follow-up interval, and the type of implant.^6,8

After reduction of a first episode of prosthetic dislocation, most studies conclude that, if malposition of the components is ruled out, conservative treatment based on physical and occupational therapy could be initiated during hospitalisation.^3,9 Anti-dislocation devices can be used during admission or even continued after hospital discharge. However, there is no evidence of their benefit, so their use remains controversial.^6,10,11 Furthermore, these devices are often poorly tolerated^9,11 and can lead to complications such as functional limitations and skin lesions, resulting in inconsistent adherence. Although no review listing the most commonly used devices in clinical practice has been found in the literature, published studies examining device use predominantly feature abduction orthoses.^10–13

This study aims to describe the preferences and confidence in the clinical practice of hip stabilisation devices among Spanish surgeons. Secondly, it seeks to describe the most frequently used type of device and the duration of use. The hypothesis was that there is no uniformity in the use of hip stabilisation devices among Spanish hip surgeons.

Material and methods

A questionnaire was developed by consensus among the authors and sent to the 259 members registered at the 22nd Congress of the National Hip Surgery Society in 2021. All attendees were invited to participate voluntarily and anonymously in the survey via email, where the study objectives were described and access to the online survey software was provided. By accessing the survey, they gave their consent to participate and for the publication of the results.

The survey consisted of a total of 7 multiple-choice questions. Four of these questions offered a free-choice option if the appropriate answer was not found among the available choices.

The first questions described the characteristics of the participants. Those related to the centre's experience included the volume of activity, the surgeon's experience (as assessed by professional career), and the surgical approach. The centre's annual total hip arthroplasty (THA) volume was classified as high (>200 THAs/year), medium (101–200 THAs/year), and low (<100 THAs/year), based on the volume reported in the national arthroplasty registry system. The annual volume of revision surgery for instability, based on the same criteria, was divided into high (>20), medium (11–20), and low (<10). Surgeon experience, based on professional career (status according to professional experience within the country's public health system), was categorised as low, medium, and high. The surgical approach used was categorised as anterolateral, posterior, anterior, and direct superior approach (DSA).

The variables included in the study were qualitative: most frequently used hip stabilisation device, duration of device use, and surgeon confidence in the device, as shown in Table 1.

Table 1.

Survey sent to attendees of the 2021 Spanish Hip Surgery Society Congress.

Most commonly used orthotic device at your center for prosthetic joint dislocation	- Braun traction
	- Knee extension orthosis
	- Abduction orthosis
	- Posterior splint
	- Abduction wedge
	- Anti-rotation boot
Time since device prescription	- <2 weeks
	- 3–6 weeks
	- >6 weeks
Confidence in the device	- Ineffective/useless
	- Valid for some specific situations
	- Useful for most cases
	- Always effective

In the question about the most frequently used hip stabilisation device, we offered a multiple-choice response with the most commonly used orthoses to our knowledge, as well as a free-choice field in case the preferred device was not among the options.

The duration of device use was divided into: <2 weeks, between 3 and 6 weeks, or more than 6 weeks. Confidence in the device was categorised into four options: ineffective, suitable for some situations, useful for most cases, or always effective.

We performed the following analysis: correlation between (1) the centre's hip arthroplasty surgical volume and device use; (2) surgical approach and confidence in the orthosis and its use; (3) surgical approach and the anti-dislocation system used; (4) surgeon's experience and confidence in the device; (5) surgeons’ experience with the type of orthosis used; and (6) confidence in the device and its use.

Data analysis was performed using RStudio 2023.03.0, version 4.3.0 (April 21, 2023, UCRT). To identify differences between groups, Kendall's correlation test was performed. Statistical significance was determined with a p-value <.05. Consensus on the variable used was considered to exist if a positive correlation was found and a p-value <.05.

Results

A total of 83 of the 259 registered participants at the congress responded to the survey, representing a 32% participation rate.

Forty-six percent of the surgeons came from medium-volume hospitals, followed by 36.1% from high-volume hospitals, and 18.1% from low-volume hospitals.

The majority of centres had a volume of revision surgeries for dislocation or instability of fewer than 10 surgeries per year (62.7%).

The majority of respondents (87%) were senior surgeons, some holding positions such as department or unit head, as well as emeritus surgeons.

The most frequently used approach among surgeons was the posterolateral approach (52%), followed by the anterolateral approach (42%). The modified anterior approach and DSA were also reported, but much less frequently.

The majority (58%) of participants used some type of device, the most common being a hip abduction orthosis (56.3%). Immobilisation time varied, with most participants using it for 3–6 weeks (45.8%), followed by those who prescribed it for more than 6 weeks. The smallest group used it for less than 2 weeks, with no significant differences between these latter groups. Forty-two percent of participants did not use any orthosis after the event.

Most participants considered the devices effective in selected cases (39.8%) and continued to use them. Within the group that considered the devices ineffective, some surgeons continued to use them (n = 11 of 33, 33%).

When comparing the variables, it was observed that the higher the number of hip arthroplasties performed at the centre, the lower the use of devices (Fig. 1).

Fig. 1.

Relationship between the centre's prosthetic volume and the use of devices.

All groups of surgeons in the study used the abduction orthosis as their preferred orthosis. Within the group of less experienced surgeons, the knee extension orthosis was used more frequently (Fig. 2). The more experienced the surgeon, the lower their confidence in the devices (Fig. 3).

Fig. 2.

Relationship between surgical experience and device type.

Fig. 3.

Relationship between surgical experience and confidence in the device.

Comparisons of device reliability showed that, in both the anterolateral and posterior approaches, most participants considered them useful in some situations (Fig. 4).

Fig. 4.

Relationship between surgical approach and confidence in the device.

The results obtained from the comparison of variables are presented in Table 2 and Figs. 1–6.

Table 2.

Results obtained from the comparison of the variables studies.

Comparison	Correlation	Yes/no	p-Value
Prosthetic volume of the centre and device use	−.118	No	.401
Surgical approach and device use	.194	Yes	.374
Surgical approach and confidence in the device	−.116	No	.750
Surgical approach and type of device	.206	Yes	.779
Surgeon's experience and confidence in the device	.011	Yes	.828
Surgeon's experience and immobilisation device	.027	Yes	.913
Confidence and use of the device	.374	Yes	.002

Fig. 5.

Relationship between surgical approach and device use.

Fig. 6.

Relationship between surgical approach and device type.

Discussion

To achieve the proposed objective, we decided to conduct a survey, since it is considered a useful method for understanding the clinical practice of hip surgeons in a reliable and relatively quick manner, while also providing an opportunity to see how current scientific evidence is integrated into patient management.^14,15

Current literature on the use of surveys among healthcare professionals has shown a decrease in response rates. The standard response rate in studies ranges between 35% and 45%, although studies with response rates below 20% are also published.^16,17 Our study has a response rate of 32%, which places it almost at the average response rate for survey-type studies published in the literature.

The majority of surgeons who responded to the survey had a high level of experience (87%), a fact that may introduce bias into the responses, as they may not be representative of the population of Spanish hip surgeons.

We observed a greater tendency to use the device among less experienced surgeons and in centres with a low volume of prostheses (<100), but this difference was not statistically significant (p > .5).

The use of the knee extension brace was very similar in the anterolateral (11%) and posterior (12%) approaches, although, due to the typical dislocation mechanism, it might be more effective in the posterior approach.

Most of the devices used were administered outside the hospital (77%, n = 37), including the abduction and extension braces. Only 11 surgeons (13.25%) used devices during hospitalisation. Another variable that would have been interesting to analyse would be the continued use of both inpatient and outpatient devices after the patient was discharged.

No studies were found in the current literature evaluating the use of hip stabilisation devices in routine clinical practice following a dislocation, whether the first or recurrent, or following primary or revision arthroplasty. Therefore, our results could not be compared. Furthermore, the literature on the effectiveness of these devices is also very limited. Most available studies have little scientific evidence, and most are retrospective with a limited sample size. These studies have not found any benefit in using orthoses to prevent dislocations.^6,10,11

Murray et al. (2012) conducted a retrospective, non-randomised observational study comparing the dislocation rate between patients treated with or without a hip stabilisation device after revision total hip arthroplasty (THA). This study included 1211 revision prostheses, making it one of the largest studies on devices. Based on surgeon preference, 502 patients wore an abduction brace, and 650 did not wear any device. After a minimum follow-up of 90 days, no statistically significant differences were found in the prevention of dislocation episodes. Of all the prostheses analysed, only 204 were revised for instability. The authors evaluated the prophylactic use of the devices without a prior episode, a factor we did not consider in our study, as we inquired about the use of the devices after a dislocation episode.

Dewal et al. (2004) presented another retrospective, non-randomised observational study that evaluated the effectiveness of abduction orthoses in preventing recurrent episodes after total hip replacement dislocation. A total of 149 patients who had suffered a dislocation were included, and the study differentiated between orthosis use after a first episode (n = 91) and after recurrent episodes (n = 58). None of the studies found significant differences between the use and absence of abduction orthoses.

None of these studies^6,10 compared different types of hip stabilisation devices; they only evaluated abduction orthoses compared to no device. However, this study showed that various types of orthoses, such as knee extension braces and abduction wedges, among others, continue to be used in clinical practice. These studies^6,10 also did not evaluate the surgical approach in relation to the device. Murray et al. (2012) only included patients who underwent a posterolateral approach, while Dewal et al. reported that the majority underwent the procedure via a posterolateral approach without specifying the percentage. In this study, a very similar frequency of use was reported between the posterolateral and anterolateral approaches. The immobilisation period was also not evaluated. Both studies maintained the immobilisation device for 6 weeks at the surgeon's discretion. In contrast, our study observed that there is also no consensus on the immobilisation time, which varies from less than 2 weeks to more than 6. Another variable that was not studied was adherence to the use of hip stabilisation orthoses. The fact that adherence is an important factor in the efficiency of their use may influence the lack of significance of the results.

We have not found a unified national or European clinical practice guideline regulating the use of devices after a dislocation. Published recommendations typically originate from information leaflets, such as those from the UK National Health Service,¹⁸ which leave the decision of these devices usage to the surgeon, without specifying the recommended type after a dislocation. The only published review that attempted to unify clinical practice guidelines regarding device use was an article by Ruspi et al.,¹⁹ which aimed to investigate whether a protocol without movement restrictions or assistive devices should be recommended to patients after total hip arthroplasty (THA), but without assessing its effectiveness after a dislocation.

One of the key findings is that no studies were found evaluating the effectiveness of currently marketed hip stabilisation devices or the characteristics of their use in clinical practice.

Limitations

This is a descriptive survey study with the inherent limitations of its design. The lack of a larger sample size, as well as the absence of randomisation of the surgeons and a trained interviewer to review and clarify the questions during the survey, may reduce the reproducibility and validity of the results.

When providing the questions, respondents were not asked to specify whether it was a first or recurrent episode, nor whether it occurred after primary or revision surgery.

The questions were based on the centre's experience and not on the individual experience of each surgeon. However, given that most of the surgeons held positions of responsibility, it is likely that there was a standardisation of criteria among the surgeons at the centre.

We excluded some results to avoid bias. Because the study sample was small, we chose not to consider, for example, the results of the correlation between the surgical approach and the volume of surgical revisions for dislocation or instability, as this would not be representative of routine clinical practice and would only introduce bias. We also excluded results related to the DSA surgical approach, as only one surgeon used it.

Conclusions

Participants considered that immobilisation devices can have a valid role in specific situations, although there is no consensus on which is the most appropriate or on the optimal duration of use.

The perception of usefulness and confidence, measured by belief in the device's usefulness, did not depend significantly on the surgical approach or the surgeon's experience, suggesting that its use is based more on subjective beliefs than on objective evidence.

Confidence in the device was the main factor associated with its use, statistically significantly so (p < .05). Even so, current literature does not demonstrate clear clinical or biomechanical benefits, which should prompt a reassessment of its routine use and, in turn, encourage research to support its usefulness.

Level of evidence

Level of evidence III.

Funding

No funding was obtained for the development of this study.

Ethical considerations

Ethical approval was not required. The survey did not include human or biological data. Also, no personal information was collected from the respondent.

Conflict of interests

The authors have no conflict of interests to declare.