Brachial plexus injury after shoulder dislocation: a literature review

Anatomical variations of the brachial plexus in adult cadavers: A descriptive study and clinical significance

BACKGROUND

Brachial plexus injury is recognized as one of the most severe clinical challenges due to the complex anatomical configuration of the brachial plexus and its propensity for variation, which complicates safe clinical interventions. This study aimed to ascertain the prevalence and characterize the types of brachial plexus variations, and to elucidate their clinical implications.

MATERIALS AND METHODS

We conducted meticulous dissections of 60 formalin-fixed cadavers' upper arm, axilla and lower neck to reveal and assess the roots, trunks, divisions, cords, and branches of the brachial plexus. The pattern of branching was noted by groups of dissecting medical students and confirmed by the senior anatomists. The variations discovered were record and photographed using a digital camera for further analysis.

RESULTS

Variations in the brachial plexus were identified in 40 of the 60 cadavers, yielding a prevalence rate of 66.7%. These variations were classified into root anomalies (2.1%), trunk anomalies (8.5%), division anomalies (2.1%), and cord anomalies (4.3%). Notably, anomalies in communicating branches were observed in 39 cadavers (83.0%): 14 with bilateral anomalies, 14 with anomalies on the left side, and 11 on the right side. These communicating branches formed connections between the roots and other segments, including trunks, cords, and terminal nerves, and involved the median, musculocutaneous, and ulnar nerves.

CONCLUSION

The frequency and diversity of brachial plexus variations, particularly in communicating branches, are significant in cadavers. It is imperative that these variations are carefully considered during the diagnostic process, treatment planning, and prior to procedures such as supraclavicular brachial plexus blocks and nerve transfers, to mitigate the risk of iatrogenic complications.

Adherence of Patients to Methods of Self-Reduction of Shoulder Dislocation Taught via Smartphones: A Medium-Term Follow-up Survey

INTRODUCTION

Self-reduction of a shoulder dislocation may reduce the time from injury to reduction and to the relief of patient discomfort. The purpose of this study was to assess adherence to earlier acquired self-reduction techniques during real-time recurrent shoulder dislocation.

METHODS

A telephone survey was conducted among 58 patients previously taught shoulder self-reduction via an instructional video sent to their smartphones during a visit to the emergency department (ED) for the treatment of anterior shoulder dislocation. Participants were queried on recurrent dislocations, use of self-reduction methods, success rate, the effect that instruction in self-reduction had on their willingness to participate in recreational sports activities, on the decision to avoid surgery, and on the overall level of satisfaction with self-reduction methods.

RESULTS

Forty-five patients (77.6%; average age 31.4±11.7 y, 10 females) were available for follow-up at an average 60.8±11.0 mo after the index visit to the ED. Eighteen of 23 patients (78.2%) who experienced a recurrent dislocation during the follow-up period attempted self-reduction, and 12 of them successfully achieved self-reduction. Sixteen patients (35.6%) reported that the knowledge in self-reduction increased their willingness to participate in recreational sports activities, whereas 4 (8.9%) patients reported that knowledge in self-reduction affected their decision not to undergo surgical stabilization.

CONCLUSIONS

Individuals who sustain recurrent shoulder dislocations should be educated on shoulder self-reduction with the aims of minimizing discomfort, obviating referral to the ED, and motivating participation in recreational activities.

Traumatic brachial plexus injury: proposal of an evaluation functional prognostic scoring system

BACKGROUND

Until now, a scoring system for determining functional prognosis in traumatic brachial plexus injury (TBPI) does not yet exist.

MATERIALS AND METHODS

This research is a retrospective study with analytic design to find data for each parameter that affect the functional prognosis in patients with TBPI and assess these factors for comparison using the DASH score. The parameters that are proven to affect the functional prognosis included in a scoring system that we have designed.

RESULTS

It resulted that the functional prognosis of TBPI patients can be determined based on the mechanism of injury, initial pain scale, pain time, level of injury, time of surgery, and initial electromyography (EMG) result.

CONCLUSION

Based on the scoring system created in this study, we can conclude that the total score <15 has a good functional prognosis, while a score of ≥15 has a bad functional prognosis, with sensitivity and specificity of 76.6% and 70.2% respectively. This research is categorized as level 3 of evidence.

Median Nerve Palsy after Shoulder Dislocation in a 10-year-old Girl: A Case Report

Introduction

Traumatic glenohumeral dislocation is very rare in skeletally immature patients, and there are no reports in the literature describing the risk of associated nerve injuries. In the general population, the most commonly affected nerve is the axillary, but anatomical variations with a common origin between the musculocutaneous and median nerves exist that alter the respective positions and courses of these nerves and can make them more prone to injury during a glenohumeral dislocation.

Case Report

A 10-year-old girl presented with incomplete median nerve palsy without any recuperation 8 months after an anterior glenohumeral dislocation. Surgical exploration was performed and revealed a common origin of the musculocutaneus and median nerve, with bifurcation just distal to the glenohumeral joint, making it susceptible to compression-elongation trauma during dislocation. A careful neurolysis was performed, and there was a complete recovery of median nerve function.

Conclusion

Glenohumeral dislocation associated with nerve injury is very rare in children. When a nerve injury occurs, one should be aware of possible anatomical variations of the infraclavicular plexus.

Anatomy and Deficiency of the Deltoid Muscle: A Review of Literature

BACKGROUND/OBJECTIVE

The deltoid muscle is impacted by common injuries and clinical procedures. This study aims to summarize the anatomy, injuries, and clinical considerations involving the deltoid muscle.

METHOD

A literature search was performed using PubMed and Google Scholar using keywords that focused on the deltoid muscle in the shoulder. Primary research articles and appropriate summary articles were selected for review.

RESULTS

Reduced deltoid muscle function can be caused by axillary nerve injury, rupture of the deltoid itself, or iatrogenic damage to the muscle. The deltoid muscle has an intimate relationship with the axillary nerve and neighboring rotator cuff muscles. Injury to these nearby structures may be masked by compensating deltoid strength. Examination maneuvers in clinic such as the Akimbo Test should be used to isolate the deltoid muscle to determine if the presenting weakness is from the deltoid itself or from other surrounding injury. Additionally, prior to performing clinical procedures, it is important to be cognitive of the injuries that can occur. For example, incisions that extend distally from the acromion should not extend beyond 5-7 cm as this is the common location of the axillary nerve and vaccine administration should take measures to avoid misplaced injections to avoid unnecessary trauma.

CONCLUSION

Deficiency of the deltoid muscle can be debilitating to patients and it is best clinical practice be aware of the anatomy, various causes, tests, and avoidance measures to help diagnose, restore or preserve normal functioning.

Axillary and musculocutaneous neuropathies

This chapter covers axillary and musculocutaneous neuropathies, with a focus on clinically relevant anatomy, electrodiagnostic approaches, etiologic considerations, and management principles. Disorders of the lateral antebrachial cutaneous nerve, a derivative of the musculocutaneous nerve, are also reviewed. We emphasize the importance of objective findings, including the physical examination and electrodiagnostic evaluation in confirming the isolated involvement of each nerve which, along with the clinical history, informs etiologic considerations. Axillary and musculocutaneous neuropathies are both rare in isolation and most frequently occur in the setting of trauma. Less commonly encountered etiologies include external compression or entrapment, neoplastic involvement, or immune-mediated disorders including neuralgic amyotrophy, postsurgical inflammatory neuropathy, multifocal motor neuropathy, vasculitic neuropathy, and multifocal chronic inflammatory demyelinating polyradiculoneuropathy.

Performance of the Fresno-Quebec Rule in identifying patients with concomitant fractures not requiring a radiograph before shoulder dislocation reduction: a multicenter retrospective cohort study

BACKGROUND AND IMPORTANCE

Although shoulder dislocation diagnosis is often solely based on clinical examination, physicians may order a radiograph to rule out a concomitant shoulder fracture before performing reduction. The Fresno-Québec decision rule aims to identify patients requiring a radiograph before reduction to avoid unnecessary systematic imaging. However, this novel approach needs further validation.

OBJECTIVE

To evaluate the performance of the Fresno-Québec rule in identifying patients who do not require a prereduction radiograph and assess the variables associated with a clinically significant fracture.

DESIGN, SETTINGS, AND PARTICIPANTS

A multicenter, retrospective cohort study from 2015 to 2021. Data were extracted from three ED university-affiliated tertiary-care centers. Patients aged ≥18 years with a final diagnosis of anterior glenohumeral dislocation were included.

OUTCOMES MEASURE AND ANALYSIS

Accuracy metrics [sensitivity (Se), specificity (Sp), positive (PPV), negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR)] of the Fresno-Québec rule were measured. Multivariable logistic regression model was used to identify variables associated with the presence of a concomitant clinically significant fracture.

MAIN RESULTS

A total of 2129 patients were included, among whom 9.7% had a concomitant fracture. The performance metrics of the Fresno-Québec rule were as follows: Se 0.96 95% confidence interval (0.92-0.98), Sp 0.36 (0.34-0.38), PPV 0.14 (0.12-0.16), NPV 0.99 (0.98-0.99), PLR 1.49 (1.42-1.55) and NLR 0.12 (0.06-0.23). A total of 678 radiographs could have been avoided, corresponding to a reduction of 35.2%. Age ≥40 years, first dislocation episode [odds ratio (OR) = 3.18 (1.95-5.38); P  < 0.001], the following mechanisms: road collision [OR = 6.26 (2.65-16.1)], low-level fall [OR = 3.49 (1.66-8.28)], high-level fall [OR = 3.95 (1.62-10.4)], and seizure/electric shock [OR = 10.6 (4.09-29.2)] were associated with the presence of a concomitant fracture.

CONCLUSION

In this study, the Fresno-Québec rule has excellent Se in identifying concomitant clinically significant fractures in patients with an anterior glenohumeral dislocation. The use of this clinical decision rule may be associated with a reduction of approximately a third of unnecessary prereduction radiographs.

Terrible Triad of the Shoulder: A Case Series and Literature Review

INTRODUCTION

The shoulder terrible triad is an underdiagnosed injury pattern consisting of anterior shoulder dislocation, rotator cuff tear, and nerve injury from the brachial plexus in its original description. The purpose of this study is to raise awareness of the condition, suggest treatment strategies, and emphasize the difficulties in treating this condition.

METHODS

This case series of seven patients from the same institution. All patients underwent x-rays before and after the reduction of the dislocation, MRI to assess the musculoskeletal injuries, and EMG and clinical examination to assess the nerve lesions. Early arthroscopic repair was opted for the rotator cuff tears. A conservative approach was chosen for the nerve lesions. Active forward flexion and external rotation, Constant score, and Visual to Analogue Scale (VAS) were recorded pre- and post-operatively.

RESULTS

All the patients showed an improvement in function postoperatively. However, four of the seven patients did not recover fully. The mean Constant and VAS scores were improved from 15.2 +/- 2.8 (12 to 19) to 67 +/- 16.6 (44 to 86) and from 7.5 +/- 1 (6 to 9) to 2.3 +/- 0.8 (1 to 3), respectively. The patients were followed up for a mean time of 28.2 +/- 10.1 months (18 to 43 months). Time-to-surgery shorter than four weeks showed better results, but not statistically significant.

CONCLUSIONS

The diagnosis of the shoulder terrible triad requires a high level of suspicion. Early arthroscopic repair for the rotator cuff tears and waiting for the nerve recovery is suggested. Delayed time from injury to surgery might be related to worse outcomes, but higher-level research is needed in this direction.

[Relevance of Early Structured Diagnosis to Successful Nerve Reconstruction: A Case Report of an Alpine Professional Skier with an Axillary Nerve Injury]

Among high-speed sports, an increased number of high-speed injuries have been observed in alpine downhill racing. We report the case of a young professional ski racer who sustained a shoulder dislocation with an avulsion of the axillary nerve during a World Cup race. After initial treatment was provided for the shoulder dislocation, the patient was left with abduction weakness and a sensory deficit in the region of the deltoid muscle. She underwent electrophysiological and clinical examinations and visited our centre with delay. We immediately performed surgical treatment with a nerve transfer and nerve transplantation. After only 11 months following her fall, she was able to resume her training program. This case report shows the importance of early diagnostic investigation, a visit to a centre of plastic surgery and the good outcome after surgical treatment in patients with peripheral nerve injuries.

The clinical diagnosis and treatment of the shoulder terrible tetrad: a case report and literature review

Traumatic anterior dislocation of the shoulder is often associated with anterior glenoid fracture or bankart injury. It can also be associated with rotator cuff injury, humeral greater tuberosity fracture, or brachial plexus injury. However, there are few clinical reports of all the above-mentioned injuries at the same time. We report a case of the left "Shoulder terrible tetrad." After closed reduction of the left shoulder dislocation, we performed one-stage arthroscopic massive rotator cuff repair (Chinese-Way technique) and anchor repair of the bony bankart injury. After 2 years follow-up, the left shoulder function recovered well and the range of motion was satisfactory. A detailed physical examination and electromyography (EMG) examination should be performed in time to avoid misdiagnosis and missed diagnosis, when the clinical manifestation of brachial plexus nerve injury appears after shoulder dislocation. The repairable rotator cuffs tears and bankart injuries can be repaired under shoulder arthroscopy in one stage.

Promotion effect of TGF-β-Zfp423-ApoD pathway on lip sensory recovery after nerve sacrifice caused by nerve collateral compensation

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.

Time to surgery and myo-d expression in biceps muscle of adult brachial plexus injury: a preliminary study

BACKGROUND

Brachial Plexus Injury (BPI) is one of the peripheral nerve injuries which causes severe functional impairment and disability. Without prompt treatment, prolonged denervation will cause severe muscle atrophy. MyoD, which is expressed by satellite cells, is one of the parameters that relate to the regeneration process in post-injury muscle and it is presumed to determine the clinical outcome following neurotization procedure. This study aims to understand the correlation between time to surgery (TTS) and MyoD expression in satellite cells in the biceps muscle of adult brachial plexus injury patients.

METHODS

Analytic observational study with a cross-sectional design was conducted at Dr. Soetomo General Hospital. All patients with BPI who underwent surgery between May 2013 and December 2015 were included. Muscle biopsy was taken and stained using immunohistochemistry for MyoD expression. Pearson correlation test was used to assess the correlation between MyoD expression with TTS and with age.

RESULTS

Twenty-two biceps muscle samples were examined. Most patients are males (81.8%) with an average age of 25.5 years. MyoD expression was found to be highest at TTS of 4 months and then dropped significantly (and plateau) from 9 to 36 months. MyoD expression is significantly correlated with TTS (r=-0.895; p = 0.00) but not with age (r=-0.294; p = 0.184).

CONCLUSION

Our study found, from the cellular point of view, that treatment of BPI needs to be done as early as possible before the regenerative potential - as indicated by MyoD expression - declined.

Axillary Artery Transection and Brachial Plexus Injury After Open Inferior Glenohumeral Dislocation: A Case Report

CASE

A judo athlete presented with an open inferior shoulder dislocation that occurred during competition. Examination revealed a transection of the axillary artery and neuropraxia of the posterior cord. Neuropraxia was resolved within 2 weeks. The axillary artery was repaired with a femoral vein graft. He regained full strength, range of motion, and function at 8 months.

CONCLUSION

Inferior glenohumeral dislocations are rare, and their management can be complicated by vascular and neurological injuries. We emphasize the importance of examination, diagnosis, and treatment of neurovascular pathologies to avoid catastrophic outcomes.

Proximal Humerus Fracture/Dislocation: Look for the Greater Tuberosity

The shoulder is the commonest major joint involved in dislocations. These are often associated with fractures of the surgical neck and/or of the greater tuberosity of the proximal humerus. A good functional recovery is associated with a successful union of the tuberosity fragment, as this carries the insertion of the superior and posterior rotator cuff tendons. A 29-year-old male patient presented to our Emergency Department (ED) after a fall off his motorbike, resulting in a left shoulder fracture dislocation and an axillary nerve injury. His shoulder was reduced under sedation in the ED, with post-reduction radiographs demonstrating a seemingly satisfactory fracture position. Later on, a computerized tomography (CT) scan was arranged which actually confirmed significant displacement of his greater tuberosity, which was not picked up on initial post-reduction radiographs. As a result of identifying the displacement, surgical fixation with a locking plate and suture construct was undertaken. This case demonstrates the ease with which greater tuberosity fractures can mistakenly be presumed as reduced on post-reduction films, whilst in fact they can be significantly displaced. This risk is especially great when only one radiographic view is obtained. The sign of the 'disappearing tuberosity' on a plain radiograph should prompt the clinician to seek further imaging by way of CT, to uncover the true position of the greater tuberosity.

Which is the most appropriate anterior glenohumeral dislocation reduction technique among three different techniques? A prospective, randomized clinical trial

OBJECTIVES

This study aims to compare three glenohumeral dislocation (GHD) reduction techniques in terms of pain and reduction time and to offer clinicians an idea of the selection of the most appropriate technique.

PATIENTS AND METHODS

This multi-center, prospective, randomized clinical study included a total of 90 patients (55 males, 35 females; median age: 29 years; range, 22 to 41 years) who had isolated anterior GHD without complication between December 2019 and December 2021. The patients were divided into three equal groups (traction-countertraction [TCT], external rotation [ExR], and Cunningham) using the block randomization method, and reductions were performed. Pre-reduction, intra-reduction, and post-reduction Visual Analog Scale (VAS) scores, reduction times, success rates, and complication rates were analyzed.

RESULTS

There was no statistically significant difference among the groups in terms of age (p=0.414), sex (p=0.954), pre-reduction VAS (p=0.175), and post-reduction VAS (p=0.204). The median intra-reduction VAS values in the TCT, the external rotation, and the Cunningham groups were 8 (range, 7 to 9), 5 (range, 4 to 7), and 4 (range, 2.75 to 5), respectively (p<0.001). The median reduction time and IQR were 105 (range, 82.5 to 120) sec for TCT, 270 (range, 232.5 to 300) sec for ExR, and 630 (range, 540 to 780) sec for Cunningham (p=0.001).

CONCLUSION

The fastest, but most painful technique is TCT, while the longest and the least painful technique is Cunningham. An inverse relationship is found between time and pain. Based on these findings, it seems to be reasonable to leave the choice of the ideal reduction technique to the clinician. The clinician should choose the technique to be used according to the conditions in the emergency department.

Patterns of Nerve Injury and Recovery Rates of Infraclavicular Brachial Plexus Lesions Following Anterior Shoulder Dislocation

PURPOSE

We reviewed our cases of infraclavicular brachial plexus injuries associated with anterior shoulder dislocation to determine patterns of injury, recovery rates, and factors associated with a poor motor outcome.

METHODS

This was a retrospective review of patients who had sustained a concomitant nerve injury following dislocation of the glenohumeral joint treated with closed manipulation. The data collected included patient demographics, injury factors, and patterns of neurological deficits. The Medical Research Council (MRC) grade for motor power was the primary outcome measure, where a grade of 4 or 5 was regarded as achieving good motor recovery. Univariate and multivariable analyses were used to identify factors associated with persistent motor weakness (MRC grades 0-3) at the final follow-up.

RESULTS

Between 2015 and 2019, 61 patients were assessed. There were 36 males and 25 females, with a median age of 64 years (interquartile range [IQR], 53-73 years). Four patterns of injury were identified: (1) isolated axillary nerve lesions; (2) single cord lesions; (3) combined lesions involving the medial and posterior cords; and (4) diffuse lesions affecting all 3 cords. Of 28 patients with isolated axillary nerve injuries, 22 recovered. All lateral cord injuries (11/11) and 20 of 24 posterior cord injuries recovered spontaneously. Recovery of hand intrinsic function from medial cord injuries had the worst outcome, with 14 of 27 patients not recovering beyond MRC grades 0 to 3. The median duration of dislocation before reduction was 6 hours (IQR, 3-12 hours). A multivariate analysis showed an association between the duration of shoulder dislocation and the likelihood of persistent motor weakness.

CONCLUSIONS

Shoulder dislocations with motor deficits should be regarded as orthopedic emergencies and reduced expediently. Persistent motor weakness may be associated with a prolonged duration of dislocation prior to glenohumeral relocation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Luxatio erecta of the humerus: the spectrum of injury of inferior shoulder dislocation and analysis of injury mechanisms

Erecta dislocation/inferior dislocation of the shoulder is considered an uncommon injury and the present knowledge stems from case reports or compilation of cases. We believe that there are reasons to believe that the injury is much more prevalent than previously stated. In this review, we discuss the mechanism of injury and based on the number of patients with unusual injury patterns at our hospitals and in the literature, the anatomical features of different variants of inferior dislocation are described. Only a few patients present with their arm still locked in abduction, and most patients with initial inferior dislocation are diagnosed with other types of dislocation or injury. Irreducible dislocation, with tissue blocking the glenoid appears to be a consequence typical of an initial inferior dislocation. Nerve and vascular injuries are overrepresented, as are humeral avulsion glenohumeral ligaments-injuries. The description of shoulder dislocations should ideally include the dislocation path and not only the final position of the humeral head.

Evaluation and Management of the Contact Athlete's Shoulder

Shoulder injuries are common in contact athletes and vary in severity because of the required complex interplay of shoulder stability and range of motion for proper function. Pathology varies based on sport but most commonly includes shoulder instability, acromioclavicular injuries, traumatic rotator cuff tears, and brachial plexus injuries. Acute management ranges from reduction of shoulder dislocations to physical examination to determine the severity of injury. Appropriate radiographs should be obtained to evaluate for alignment and fracture, with magnetic resonance imaging commonly being necessary for accurate diagnosis and management. Treatments range from surgical stabilization in shoulder instability to repeat examinations and physical therapy. Return-to-play decision making can be complex with avoidance of reinjury and player safety being of utmost concern. Appropriate evaluation and treatment are vital because repeat injury can lead to long-term effects due to the relatively high effectsometimes seen in contact sports.

Delayed Onset of Subclavian Artery Pseudoaneurysm With Brachial Plexus Compression Following Gunshot Wound Injury

Early diagnosis of brachial plexus injuries is crucial to prevent long-term morbidity and improve outcomes. We present a unique case of delayed onset of brachial plexus compression two months following a traumatic gunshot injury causing multiple injuries including a T1 vertebral body comminuted fracture and pneumothorax. The patient experienced significant pain and progressive neurological examination changes during follow-up visits, and thus duplex ultrasound and computed tomography (CT) angiography were performed, which demonstrated a left subclavian artery pseudoaneurysm. This was managed operatively by evacuation and interposition bypass. Injuries to the cervical and upper thoracic spine are complex, and when patients present with new-onset neurological findings, axillary swelling, or significant uncontrolled postoperative pain, secondary complications should be suspected. Patients at a high risk of vascular reinjury should be routinely monitored at follow-up to prevent the development of progressive neurological damage to the brachial plexus.

«Terrible triad» of the shoulder. Biomechanicalsemi-natural modeling andjustificationto rotator cuff restoration

The aim of this study: was determine the force of tension and deformation of axillary nerve in rupture rotator cuff and paresis of deltoid muscle of the shoulder joint. Material and methods: Semi-natural modelling based on the axial scans spiral computed tomography of the intact shoulder joint was performed to determine the degree of traction load on the axillary nerve with distal displacement shoulder head and tendon rupture which paresis of the deltoid muscle. Result: The values of deformations for axillary nerve being at the limit of tissue strength at distal displacement of humeral head of the model by 50 %, progressively increased with increasing distal displacement of humeral head to 100 % of its diameter, reaching values 1.7 times higher than the strength nervous tissue. Conclusion: The progressive changes occurring in the axillary nerve under the action of traction loads, and as a consequence of its ischemia, over time can lead not only to demyelination, but also to the defeat of the axons themselves atrophy of its fibers. In turn, deltoid muscle atrophy increases the traction load on the affected axillary nerve, which forms a vicious circle. The only possible option to "break" the vicious circle is restore the stabilizing structures damaged during the injury, among which one of the most important is the tendons of the rotator cuff of the shoulder. Surgical restoration of the integrity rotator cuff of the shoulder reduces the traction load acting on the axillary nerve, which in turn significantly improves the conditions for reinnervation of the deltoid muscle.

Functional deficits as a result of brachial plexus injury in anterior shoulder dislocation

The incidence of brachial plexus injuries in anterior shoulder dislocation remains relatively uncommon. A retrospective study was conducted to observe the natural neurological recovery of patients following these injuries over a 2-year period. Muscle power according to the Medical Research Council scale and sensation were measured from presentation to discharge. In 28 patients, the power grade of proximal muscles supplied by nine injured nerves failed to improve over a median follow-up of 5 months. There was no statistically significant improvement in sensation over a median follow-up of 6 months. Poorer recovery in muscle power score was related to advancing age, whereby every decade increased the risk by approximately 30%. Anterior shoulder dislocation with a plexus injury carries a risk of permanent nerve injury. Patients should be referred for specialist nerve assessment leading to rehabilitation and timely early nerve reconstruction, if indicated.Level of evidence: IV.

Quadrangular Space Syndrome: A Narrative Overview

OBJECTIVE

The purpose of this narrative review of the literature is to provide an overview of quadrangular space syndrome with special attention to its clinical presentation, differential diagnosis, and treatment.

METHODS

A narrative review of the English-language, peer-reviewed literature was performed using the key words "axillary nerve," "quadrangular space," "quadrilateral space," and "posterior humeral circumflex artery." Databases searched were Medline Complete, Cumulative Index to Nursing and Allied Health Literatures, and Index to Chiropractic Literature. The search period was from 1983 through January 2020.

RESULTS

There were 85 articles selected for this review. A summary and overview are provided.

CONCLUSION

Quadrangular space syndrome is an uncommon cause of shoulder pain. Clinicians should consider it as a diagnosis after ruling out more common shoulder conditions and examining other concurrent diseases.