The 'Holy Grail' of shoulder dislocations: a systematic review on traumatic bilateral luxatio erecta; is it in reality a once-in-a-lifetime experience for an orthopaedic surgeon?

According to our literature review, TBLE seems to be an extremely rare injury, with only 51 cases to date in the literature. Forty-one papers (forty-two cases) were originally published in English and nine in other languages (German [8, 11‐13], Japanese [14], Korean [15], Spanish [16], Bosnian [17], French [18]). Mean age of the patients in the English literature was 55 years old (range 19–80 years). There is a predominance of males compared to females with an incidence of 67% (28 out of 42 cases).

Falls were the commonest mechanism of injury in 32 out of 42 cases (76.2%), particularly high energy falls (fall from a height [19‐23], ladder [10, 24‐34] from a horse [35], and from a boat [36] accounting to 20 out of 42 cases (45,2%), while fall from standing height [37‐46] accounting to 10 out of 42 cases (23,8%)). Road traffic accident was the cause of TBLE in eight cases [47‐54] (19%). In two cases, the injury was related to an attempt to hold/prevent a heavy object from falling above the head [55, 56]. In one case, the patient fell from a docked boat while she was trying to grab a tree [36], while another patient sustained a fall against a wall [37]. Only two of the above-mentioned cases were related to a sports injury [56, 57]. No other information about the exact mechanism of fall were found in one report [53]. In the most uncommon mechanism of injury, patients’ arms were trapped in a cement mixer when the machine started accidentally [58], this mechanism of injury was categorized by the authors as a work-related one.

Two main reduction techniques for LE have been described in the literature. The traction–counter-traction technique has been described by Freundlich et al. [59] and the two-step technique by Nho et al. [60] The second one involves a gentle rotation to change the position of the humeral head transforming the dislocation to an anterior one, and then on the second step, the reduction of the anterior shoulder dislocation with a maneuver of choice. These techniques may be performed with or without general anesthesia.

Close reduction has been achieved with traction–counter-traction in both sides in 30 cases [19, 23, 25, 27‐30, 32‐43, 45‐53, 55, 58]. Different technique on each side was used in two cases [21, 44] and the two-step technique has been used in three cases [20, 56, 57]. General anesthesia was used in only four of the above-mentioned cases [25, 26, 28, 42]. Only one case required open reduction due to concomitant injuries [22].

Finally, in six cases, the reduction technique which has been used is not mentioned [10, 24, 26, 31, 54]

TBLE is highly associated with neurovascular injuries. In our systematic review, out of 42 cases, neurological deficits were found in 18 [10, 19, 21, 26, 29‐31, 35, 36, 38, 39, 41, 47‐49, 52, 53, 58] (42,8%) including 1 case with bilateral complete brachial plexus tear [38] (accompanied with rotator cuff tear). On the other hand, vascular complications have been found in only one case. Particularly, Garcia et al. reported deep vein thrombosis extended from the left axillary to the proximal portion of the left brachial vein [49].

Proximal humeral fractures were reported in nine patients [21, 22, 26, 40, 42, 43, 50‐52] (21,42%). Unilateral fracture of the greater tuberosity was found in five of these cases [21, 22, 40, 50, 51], while bilateral involvement was found in four patients [26, 42, 43, 52]. More severe fractures of the proximal humerus have been reported in only one case. In this case, a greater tuberosity fracture has been combined with a split head fracture [26].

Rotator cuff tears have been noted in nine patients [10, 28, 29, 33, 34, 38, 39, 45, 53] (21,42%), which were usually accompanied with concomitant injuries (mainly nerve injuries). The vast majority of the tears were bilateral [28, 29, 33, 34, 38, 39, 45, 53]. Labral tear has been reported in one case [21]. Redislocations were presented in three papers, including a case of bilateral redislocation after successful close reduction, which has been reported by Newman and Bendal [47], while Kessler et al. referred subsequent unilateral non-traumatic anterorinferior shoulder dislocation [44]. Somville [26] reported a case of an in-hospital humerus fracture and dislocation of the humerus head infraglenoidal in the left armpit after an initially successful reduction documented on a radiological basis.

No complications were reported in nine cases [20, 23, 25, 27, 32, 37, 46, 56, 57], while no further information was given in two papers [24, 54].

Summary of demographics, mechanism of injury, reduction technique, and complication rates of the cases published or officially translated in English is summarized in Table 4.

Based on the aforementioned findings, bilateral cases of LE are associated with a notably higher rate of complications compared to unilateral cases. Specifically, 73.8% of the patients (31 out of 42) with TBLE experienced some form of complication or concomitant injury (Tables 2, 4). When considering injured shoulders, the percentage of complications or concomitant injuries was also found to be substantial. Out of the 84 injured shoulders, 56 (57.2%) had some kind of complication or concomitant injury (Table 4). Furthermore, the incidence of soft tissue injuries like the ones on the rotator might be even higher, as in older published papers, there are no references regarding MRI results, a fact that could lead to the underestimation of this complication.

Nambiar et al. [4], in their systematic review regarding LE, reported a rate of neurological complications of 29%, while Gökkus et al. [61] estimated this incidence after LE to be up to 28%. Both studies included bilateral cases as well; particularly, Nambiar et al. encompassed 29 cases of TBLE, without providing further information regarding the analysis of papers with neurological complications. Conversely, Gökkus et al. presented a more comprehensive analysis, reporting 16 cases of LE with neurological deficits, of which 7 were bilateral. In both papers, the percentages were calculated on a per-patient basis. After analyzing these two systematic reviews, we hold a strong belief that incorporating bilateral cases does not offer a precise estimation of the rate of neurological complications. Our exclusive review, focusing solely on patients with TBLE, indicates that the rate of neurological deficits is approximately 42.8% on a per-patient basis (18 out of 42 cases). However, when considered on a per-shoulder basis, this percentage decreases to 28.57% (24 out of 84 injured shoulders) and remains consistent with the findings reported in the aforementioned analyzed papers regarding unilateral LE.

But which are the reasons behind the higher per-patient incidence of neurological complications in TBLE cases? The primary and clearly apparent answer for this question is the bilateral involvement itself. When both shoulders are dislocated, it mathematically doubles the potential for complications or concomitant injuries. Furthermore, to provide possible alternative explanations for this higher incidence of neurological complications on a per-patient basis, we propose a twofold hypothesis: first, the mechanism of injury in TBLE cases tends to be more severe compared to unilateral ones. The substantial forces involved in such injuries have the potential to inflict additional trauma upon the surrounding anatomical structures, including the nerves. Consequently, the likelihood of neurological complications is amplified, resulting to the observed higher incidence in TBLE cases. Second, the simultaneous dislocation of both shoulders in TBLE renders the upper trunk vulnerable and unprotected. This lack of safeguarding exposes critical neurovascular structures, such as the brachial plexus and the axillary nerve, to potential secondary damage. The compromised integrity of these vital components may contribute significantly to the increased occurrence of neurological complications.

While our hypothesis is based on the available evidence and logical reasoning, we acknowledge that further research is needed to validate and explore these factors in greater detail.

In this article, we performed a systematic review of a rare clinical entity such as Traumatic Bilateral Luxatio Erecta. The results are based only on case reports that have been published and not on a general setting of large series, as the rareness of this traumatic pathology does not allow broader investigation settings. As a result, the quality of the reviewed article could not be documented.

The inclusion of only two databases in our review could be a limitation, but we strongly believe that the selected ones are ideal for the publication of this kind of reports and the number of cases, which are presented in this manuscript and the total number of cases is reflecting the reality.