A Retrospective Study of 1076 Cases of Shoulder Dislocation at a Single Center in Türkiye to Evaluate the Role of Post-Reduction Radiography in the Detection of Clinically Significant Fractures

Introduction

Shoulder dislocations account for half of all major joint dislocations, with anterior dislocation being the most prevalent [1]. The shoulder’s instability is attributed to its shallow glenoid, which only connects with a small portion of the humeral head. It is the most frequently dislocated joint in the body, capable of dislocating anterior, posterior or inferior, either fully or partially, although anterior dislocations are most common [1,2]. Dislocations can result in stretching or tearing of the fibrous tissue that binds the bones together, complicating the injury. A significant force, such as a blow to the shoulder, is typically required to displace the bones. Excessive rotation can also dislodge the shoulder from its socket [3,4]. Sports-related injuries, particularly those from contact sports, are common causes of shoulder dislocation. Additionally, trauma from motor vehicle accidents and falls frequently leads to dislocations [1–4].

Anterior shoulder dislocation is a common orthopedic injury that can occur in both traumatic and non-traumatic settings. After reduction, a control radiograph is sometimes taken to assess the adequacy of reduction and to rule out associated fractures [5,6]. However, the necessity of routine post-reduction radiographs has been a topic of debate in the medical community. In this article, we will review the available evidence to answer the question of whether a control radiograph should be taken after reduction in anterior shoulder dislocations [7].

Anterior shoulder dislocation is a common injury, with an incidence of 23.9 per 100 000 person-years in the general population [5,8]. It is more common in young males and in those who engage in contact sports or other activities that involve repetitive overhead motions [9–11]. The most common mechanism of injury is a fall onto an outstretched hand with the arm abducted and externally rotated [12]. Anterior shoulder dislocation is a painful condition that requires prompt medical attention. Reduction of the dislocated shoulder should be performed as soon as possible to alleviate pain and prevent further damage to the joint [13].

After reduction of the anterior shoulder dislocation, a control radiograph is often taken to evaluate the adequacy of reduction and to rule out associated fractures (Figure 1) [11–14]. The most commonly used radiographic views are anteroposterior (AP) and axillary views. The AP view is useful for assessing the alignment of the humeral head with the glenoid fossa, while the axillary view provides information about the presence of associated fractures, such as Hill-Sachs lesions or Bankart fractures [15].

The use of post-reduction control radiographs in anterior shoulder dislocation has been a subject of debate among healthcare professionals [16]. Some argue that routine post-reduction radiographs are unnecessary and can lead to increased radiation exposure and healthcare costs, but others believe that post-reduction radiographs are essential in detecting fractures and ensuring that the reduction is successful. Therefore, this retrospective study of 1076 cases of shoulder dislocation at a single center in Türkiye aimed to evaluate the role of post-reduction radiographs in the detection of clinically significant fractures (Figure 2) (requiring repeat intervention, surgery, or follow-up).

Material and Methods

PATIENT COHORT:

This study was conducted at a tertiary educational research hospital with an annual emergency department admission rate of approximately 470 000. The study retrospectively examined patients with radiographically confirmed anterior shoulder dislocation who presented to the Ankara Bilkent City Hospital Emergency Department between March 2019 and November 2022, after study approval by the hospital’s ethics committee (approval number E. Committee-E1-22-3080). The patients’ demographic data, mechanism of injury, pre- and post-reduction radiograph readings, reduction method and which clinic performed it, sedation or analgesia administered, previous history of shoulder dislocation, whether the shoulder was reduced, patient outcome, and time of emergency department admission and discharge were recorded. Patients whose data could not be accessed from the hospital automation system were excluded from the study.

RADIOLOGICAL ASSESSMENT:

We included patients who had pre- and post-reduction anterior-posterior (AP) and axillary shoulder radiographs. The radiographs were obtained using the GE Optima XR646 machine (Genera Electric Healthcare, Chicago, Illinois, USA) in our emergency radiology department. The AP radiographs were obtained using 60–70 kVp and 10–18 mAs values and a technique that includes the proximal third of the humerus and the sternoclavicular joint. The axillary shoulder radiographs were obtained using 50–60 kVp and 8–15 mAs values and a technique that includes the proximal third of the humerus and the glenohumeral joint. These radiographs were retrospectively scanned and included in the study. All evaluations were performed by a senior radiologist using the picture archiving and communication system workstation (Centricity; GE Healthcare, Chicago, Illinois, USA).

STATISTICAL ANALYSIS:

The research data underwent analysis using the IBM SPSS Statistics for Windows, Version 22.0 (Armonk, NY: IBM Corp.) software package. The normality of the data distribution was assessed through the Kolmogorov-Smirnov test. Normally distributed data are presented as mean±standard deviation. Statistical comparisons were performed with the independent samples t test for normally distributed quantitative data and the Pearson chi-squared test was used to compare ratios for categorical variables, with a significance threshold set at P<0.05.

Results

During the 44-month study period, radiographically confirmed anterior shoulder dislocation was identified in 1138 patients, of which we excluded 62 patients for whom we could not access data from the information automation system. The mean age of the 1076 included patients was 43.3±21.6 years, with 809 (75.1%) being male (Table 1).

When the injury mechanisms of the patients were examined, 185 (17%) had non-traumatic and 891 (82.8%) had traumatic causes for their admission. Among traumatic causes, the most common form of admission was simple falls from the same level in 825 (76.6%) patients, followed by 38 (3.5%) sports injuries, 21 (1.9%) blunt traumas, and 7 (0.6%) traffic accidents. Anterior shoulder dislocation was cause of the first emergency department visit for 924 patients, while 152 (14%) patients had recurrent dislocations with a non-traumatic mechanism (Table 1).

The most commonly used reduction technique was traction/counter-traction, which was applied to 828 (76.9%) patients, followed by the Kocher method, which was applied to 171 (15.8%) patients. Among them, 28 (2.6%) patients were reduced by scapular manipulation, 15 (1.3%) by the Milch technique, and 3 (0.2%) by other methods. A total of 31 (2.8%) patients underwent surgery and a total of 128 (11.7%) patients received sedo-analgesia in the emergency department (Table 1).

Overall, 878 (81.5%) patients were reduced by orthopedists, while 196 (18.2%) patients were reduced by emergency physicians. The reduction procedure performed by emergency physicians was found to be statistically significantly lower (P<0.01).

A total of 63 (6.2%) patients did not have a post-reduction radiograph. Pre-reduction and post-reduction radiographs of the remaining 1076 patients were read by an independent radiologist. In 27 (2.6%) of the pre-reduction radiographs of the 1076 patients, a fracture was detected (9 greater tuberosity fractures, 11 Hill-Sachs fractures, and 7 Bankart fractures), while a total of 32 (3.1%) patients had a fracture on the post-reduction radiographs (9 greater tuberosity fractures, 15 Hill-Sachs fractures, and 8 Bankart fractures), and there was no statistically significant difference between the 2 groups (P=0.142). Four patients with newly detected Hill-Sachs fractures and 1 patient with a newly detected Bankart fracture on the post-reduction radiographs did not have a record of hospital readmission or surgery during retrospective follow-up after discharge from the emergency department (Table 2).

The duration of time for the 63 patients who did not have a post-reduction radiograph was 106 min, whereas the average time taken for the 986 patients who were discharged from the emergency department after undergoing a post-reduction radiograph was 237 min. Additionally, the hospital stay of patients who were discharged after a post-reduction radiograph was read was significantly longer, with a P value of less than 0.01 (Table 2).

Discussion

LIMITATIONS:

One limitation of our study is that it was conducted retrospectively, which may have led to incomplete data. Moreover, the study was conducted in a single center, which limits the generalizability of our findings. Further research is needed to confirm our results and to determine the cost-effectiveness of routine post-reduction radiographs in anterior shoulder dislocation. Overall, our findings suggest that routine post-reduction radiographs may not be necessary in all cases of anterior shoulder dislocation, and that the decision to perform a post-reduction radiograph should be based on the individual patient’s clinical presentation and risk factors.

Conclusions

In conclusion, the decision to perform a post-reduction control radiograph in anterior shoulder dislocation should be based on clinical judgment and individual patient factors. Our study supports that routine use of post-reduction radiographs in all cases of anterior shoulder dislocation may not be necessary and could potentially expose patients to unnecessary radiation exposure and healthcare costs. Additionally, shortening the examination time in the emergency department by not taking a follow-up radiograph will help prevent overcrowding. However, in cases where there is concern for a possible associated fracture or a complicated reduction, a post-reduction radiograph should be obtained to ensure proper diagnosis and treatment.