Os Acromiale: Reviews and Current Perspectives

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.

The frequency of os acromiale in 751 shoulder MRI of Saudi population

Background: Os acromiale (OA) is an uncommon pathology with a variable prevalence rate among different populations. Objectives: The aim of this study was to report the frequency of OA utilizing shoulder MRI of patients with shoulder pathology. Methods: It was a retrospective study. After obtaining our IRB approval, we gathered all shoulder and upper arm MRIs from the radiology department and evaluated them. Results: The prevalence of OA was found to be 3.32%. The mean age of the affected patients was 50.87 years (25-81). Conclusion: The rate of OA in patients presenting with shoulder pain is 3.32% in Saudi Arabia, which correlates with what has been previously reported in the literature.

Physeal injuries of the clavicle: pediatric counterparts to adult acromioclavicular and sternoclavicular joint separations

The epiphyses at the medial and lateral ends of the clavicle are small, ossify relatively late, and may not fuse until early adulthood. Because of this unique anatomy, pediatric and young adult injuries that involve the clavicle often differ from the patterns typically seen in older adults. Clavicular trauma that affects the acromioclavicular joint laterally or sternoclavicular joint medially often results in a physeal fracture and as such, can go unrecognized or be mistaken for a joint dislocation. Radiographic assessment is challenging, particularly when the epiphysis is not yet ossified. However, MR imaging allows for visualization of the cartilage, periosteum and perichondrium, and ligaments of the affected joints. Lateral clavicle physeal injuries can be categorized by the Dameron and Rockwood system, the pediatric correlate to the Rockwood classification of adult acromioclavicular joint injuries. Medial clavicle physeal fractures, similar to adult sternoclavicular joint dislocations, may result in anterior or posterior displacement. Because of their great ability to heal and remodel, clavicular physeal fractures respond better to conservative management than true acromioclavicular or sternoclavicular joint dislocations. Therefore, it is essential to recognize the true nature of these injuries, as there are implications for successful treatment and appropriate prognosis.

Living with lower limb traumas and below-knee amputation in a Jordanian Late Ottoman nomadic community

OBJECTIVE

Paleopathological analysis is combined with ethnohistorical, ethnographic and ethnomedical reports to assess the sociocultural implications for a historical nomadic Bedouin female following her survival of a below-knee amputation and multiple injuries to the stump.

MATERIALS

A middle-aged female recovered from a nomadic-style burial dated to the Late Ottoman Period (1789-1918) in Jordan's Wadi ath-Thamad region.

METHODS

Macroscopic and radiographic assessment.

RESULTS

A supracondylar femur (Hoffa) fracture, knee complex injury and lower leg amputation were observed on the right lower limb. Other pathological lesions that may have affected movement included bilateral os acromiale, intervertebral disc disease, osteoarthritis and right hook of hamate fracture.

CONCLUSIONS

The individual survived a below-knee amputation, two injuries to the stump, and likely experienced lower back pain. Mobility may have been painful, but she likely functioned within the community performing gender-specific daily tasks within the family tent and designated community female workspaces. Ethnohistoric and ethnographic reports suggest that marital demotion by other wives or a return to her father's tent may have occurred.

SIGNIFICANCE

Healed multiple injuries and amputation affecting one limb are rare in paleopathological literature.

LIMITATIONS

It is uncertain whether the amputation or either of the stump injuries occurred during the same event. If they resulted from separate events, slight hip joint osteoarthritis suggests that the amputation preceded the other injuries.

SUGGESTIONS FOR FURTHER RESEARCH

Full pathological assessment of individuals with amputations may provide additional insight into impairment resolution, health problems and injury arising from impairment following amputation.

Subacromial impingement syndrome: association of multiple magnetic resonance imaging parameters with shoulder function and pain

INTRODUCTION

Shoulder pain is one of the most common complaints in orthopaedics. This study focusses on the relationship between shoulder function in subacromial impingement syndrome and imaging criteria in magnetic resonance imaging (MRI).

MATERIALS AND METHODS

This prospective clinical trial included 69 patients treated for subacromial impingement syndrome. Shoulder function (Constant Score, range of abduction, abduction force) and pain were correlated with the following MRI parameters: tendinosis of the rotator cuff, "halo-sign" around the biceps tendon, subacromial distance, critical shoulder angle, size of subacromial osteophytic spurs and maximum width of subacromial and subdeltoid bursa. Statistical analyses included Pearson's and Spearman's coefficients of correlation, multiple regression analysis and Student's t-test.

RESULTS

The Constant Score was correlated positively with the critical shoulder angle (r = 0.313; p = 0.009) and inversely with a "halo-sign" around the biceps tendon (rho =  -0.384; p = 0.001). There was no significant correlation between spur size and shoulder function, but the size of the subacromial and subdeltoid bursae was positively correlated with the subacromial spur's size (subacromial bursa: coronal plane: r = 0.327; p = 0.006; sagittal view: r = 0.305; p = 0.011; subdeltoid bursa coronal view: r = 0.333 p = 0.005). The width of the subdeltoid bursa in coronal plane was positively correlated with shoulder pain (r = 0.248; p = 0.004) and negatively with the range of abduction (r =  -0.270; p = 0.025), as well as the mean (r =  -0.332; p = 0.005) and maximum (r =  -0.334; p = 0.005) abduction force.

CONCLUSIONS

Shoulder function and pain in subacromial impingement are best predicted by the width of the subdeltoid bursa measured in the coronal MRI plane as an indicator of bursitis as well as the presence of a "halo-sign" around the biceps tendon indicating glenohumeral joint effusion. Presence of a subacromial spur could lead to subacromial and subdeltoid bursitis, which impairs shoulder function. Shoulder function seems not to be compromised by the presence of a subacromial spur in absence of bursitis. This study was registered at the German Clinical Trials Register on 08 February 2013 (ID: DRKS00011548).

Surgical treatment of a symptomatic os acromiale by arthroscopy-assisted double-button fixation: a case report

CASE

We present the case of a symptomatic os acromiale in a 51-year-old female patient. Arthroscopy-assisted treatment was performed using a double-button fixation system and additional suture cerclage. The patient presented with complete radiographic bone union, pain relief, improved range of motion and did not require hardware removal at the 12-month follow-up.

CONCLUSION

The achievement of persistent consolidation between the two fragmented bone surfaces, without further need for hardware removal and improved clinical outcome, suggests that our minimally invasive technique is appropriate for this specific indication. To our knowledge, this technique has not been described in the literature yet.

Arthroscopic Fixation of Symptomatic Meso-Type Os Acromiale: Technical Note

Symptomatic Os acromiale can cause pain, impingement, and reduced range of movement. Disruption of the syndesmosis can result in significant pain and functional impairment; this may occur after trauma. Symptomatic Os acromiale is treated by either excision or fixation. Fixation via open technique is the mainstay of surgical intervention; however, recently, arthroscopic methods were used. In this technical note, we discuss the modification for all arthroscopic Os acromiale fixation; the fixation screws are introduced in anteroposterior fashion, employing the advances in orthopaedic fixation devices. Arthroscopic fixation is not widely adopted, possibly due to availability of implants and perceived difficult learning curve. We report this technique and demonstrate reproducibility with excellent results.

Anatomical variants of the acromioclavicular joint influence its visibility in the standard MRI protocol in patients aged 18-31 years

Purpose

Visualization of a structure in orthogonal planes is essential for correct radiological assessment. The aim was to assess the utility of the standard MRI protocol for the shoulder in the assessment of the acromioclavicular joint (ACJ).

Methods

A total of 204 MRI scans of the shoulder were re-reviewed. Visibility of the ACJ in orthogonal planes was assessed, and the type of acromion and the angle between the ACJ and the glenoid cavity were assessed by two observers.

Results

Agreement in the assessment of ACJ visibility was moderate to substantial. The ACJ was visible in the three anatomical views in 48% (confidence interval [CI] 95% = [41–54%]) of the examinations, and no significant difference regarding gender or age was noticed. The mean angle between the ACJ and the glenoid cavity was 41.12 deg. CI95% = (39.72, 42.53) in the axial plane, 33.39 deg. CI95% = (31.33, 35.45) in the coronal plane and 52.49 deg. CI95% = (50.10, 54.86) in the sagittal plane. When the ACJ was visible in the sagittal and axial planes, significant differences were noticed in the remaining planes (p < .05).

Conclusion

Anatomical variations of the ACJ influence its visibility in the standard MRI protocol for examining the shoulder, making this protocol insufficient for ACJ assessment in the examined population.

Prevalence of Os Acromiale in Thai Patients With Shoulder Problems: A Magnetic Resonance Imaging Study

Background:

Os acromiale is an anatomic variant in which the acromial ossification center fails to fuse. It may lead to painful shoulder conditions and surgical intervention may be required for treatment. The prevalence of os acromiale in South Koreans (0.7%) has previously been the representative number for the Asian population, and it is lower than that in the Black and White populations.

Purpose:

To determine the prevalence of os acromiale in Thai patients with shoulder disabilities who underwent magnetic resonance imaging (MRI).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We retrospectively reviewed the MRI scans of patients with shoulder disabilities between January 2019 and May 2021 at a single institution. The relationship of sex, age, and shoulder diagnosis to the presence of os acromiale was then analyzed.

Results:

A total of 940 MRI scans in 848 patients were evaluated, of which 20 shoulders were detected to have os acromiale, a prevalence of 2.13%. The mean age of the patients was 60.25 years, with 60% being female and 40% male. Of the 20 os acromiale cases, 17 (85%) were preacromiale, 1 (5%) mesoacromiale, and 2 (10%) meta-acromiale. The associated diagnoses were as follows: 75%, full-thickness rotator cuff (RC) tear; 10%, partial-thickness RC tear; 5%, RC tendinopathy with symptomatic os acromiale; 5%, anterior shoulder instability with full-thickness RC tear; and 5%, frozen shoulder. Age, sex, and associated shoulder disability were not associated with the presence of os acromiale.

Conclusion:

In Thai patients with shoulder problems who required MRI evaluation, the prevalence of os acromiale was 2.13%. This is lower than the prevalence from other ethnic groups but slightly higher than that from the same ethnic group (Korea). There was no relation between the presence of os acromiale and shoulder pain, regardless of diagnosis.

Shoulder impingement: various risk factors for supraspinatus tendon tear: A case group study

A total of 680 cases of monolateral shoulder pain and functional impairment were included, and Chi-Squared tests was incorporated to test for possible associations.No relation between impingement syndrome and potential risk factors was found, such as presence of down slopping (P = .083), presence of ossification acromiale (P  = .102), presence of calcific tendinitis (P  = .144), types of acromion (I [P = .600], II [P = .536], III [P = .633] and IV [P = .832]) and grade of acromioclavicular degenerative changes (mild [P = .077], moderate [P = .111], and severe [P = .700]). However, a significant relationship was uncovered between impingement syndrome and risk factors such as gender (X2 = 7.004, df = 1, P = .08) (where females were more prone), history of shoulder dislocation (X2 = 19.440, df = 1, P = .001), presence of supraspinatus tendon tear or tendinopathy (X2 = 69.344, df = 1, P = .001) and supraspinatus complete tear (X2 = 13.593, df = 1, P = .001). A significant relationship was found between the type of supraspinatus pathology and factors such as gender (female more prone) (X2 = 34.719, df = 3, P = .01), presence of down slopping (X2 = 57.765, df = 3, P = .01), history of shoulder dislocation (X2 = 148.880, df = 3, P = .001), type III of the acromion (X2 = 12.979, df = 3, P = .005), presence of acromioclavicular generative changes mild (X2 = 76.408, df = 3, P = .001) and moderate (X2 = 29.697, df = 3, P = .001), and acromiohumeral distance of ≤3 mm (X2 = 18.915, df = 3, P = .001), 3.1 to 6 mm (X2 = 13.212, df = 3, P = .004), and 9.1-12 mm (X2 = 15.066, df = 3, P = .002). Overall, the Magnetic Resonance Imaging results yielded high sensitivity for detecting full-thickness supraspinatus tears.Considering the findings, this study may help radiologists understand the salient risk factors and identify which factors are mainly responsible for supraspinatus tendon tears and the respective grade of tear (articular partial, bursal partial, complete, or tendinopathy).

Os acromiale may be a contraindication of the clavicle hook plate: case reports and literature review

Background

Os acromiale can be potentially missed or misdiagnosed as acromion fracture, and this can affect treatment determination if it is complicated with an ipsilateral shoulder injury. The clavicle hook plate is a widely used technique for distal clavicle injuries, leading to transacromial erosion, particularly when in the presence of os acromiale.

Case presentation

A 70-year-old man and a 78-year-old man who had limited mobility and severe pain in their right shoulders following falls attended the emergency center. Both patients were diagnosed with os acromiale with CT or MRI and acute distal clavicle fracture or acromioclavicular joint dislocation. Following a comprehensive evaluation, os acromiale may limit the application of a clavicle hook plate due to potential transacromial erosion. The distal clavicle fracture with ipsilateral os acromiale received treatment with a volar radius locking T plate, and the acromioclavicular joint dislocation with ipsilateral os acromiale was reconstructed using suture anchors. Both yielded satisfactory outcomes and voided transacromial erosion.

Conclusions

Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate. An axillary lateral radiograph is recommended to detect potential os acromiale in patients using a hook plate.

Superior Capsular Reconstruction With Autologous Fascia Lata Using a Single Lateral-Row Technique Is an Effective Option in Massive Irreparable Rotator Cuff Tears: Minimum 2-Year Follow-Up

PURPOSE

The purpose of this study was to evaluate clinical and radiologic outcomes of arthroscopic superior capsular reconstruction (ASCR) with fascia lata autograft in patients with irreparable rotator cuff tears (IRCTs) performed using a single lateral-row fixation technique.

METHODS

We studied a retrospective case series of patients with large or massive IRCTs for ASCR with fascia lata autograft. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and the Constant score. Healing of the graft was assessed by magntic resonance imaging or ultrasound. Acromiohumeral distance was evaluated by radiographs.

RESULTS

Thirty-one patients with an average age of 61 years and an average follow-up of 35 months (24-51 months) underwent ASCR with fascia lata autograft. There was a significant improvement in VAS (7.7-0.7), Constant score (36.0-78.7), forward elevation (115°-171°), external rotation (33°-50°), strength (0.3 kg-2.3 kg), and acromiohumeral distance (6.1 mm-8.6 mm) (P < 0.001). Graft failure was present in 13.8% of patients, as shown by magnetic resonance imaging (26 patients) or ultrasound (3 patients). Patients with failed ASCR showed worse Constant scores (68.5.8 vs 80.2, P = 0.007), worse VAS (2.5 vs 0.4, P = 0.00002), worse external rotation (20° vs 54°, P = 0.004), lower acromiohumeral distance (5mm vs 9mm, P = 0.007), and a high association with the presence of os acromiale (χ²P = 0.003). No revision or subsequent surgical procedures were required.

CONCLUSIONS

ASCR, with autologous fascia lata and single lateral row configuration, is an effective option in irreparable rotator cuff tears and results in clinical and radiologic improvement.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Rotator cuff assessment on imaging

The rotator cuff is a group of four muscles and tendons surrounding the shoulder joint providing it strength and stability. The rotator cuff consists of the subscapularis, supraspinatus, infraspinatus and teres minor. Many shoulder complaints are caused by rotator cuff pathology such as impingement syndrome, tendon tears and other diseases e.g. calcific tendonitis. Diagnosis starts with clinical history and physical examination, after which imaging is often used to help confirm clinical findings depending on the differential diagnosis. The aim of the article is to review the frequently used imaging modalities to assess the rotator cuff and cuff-related disease, specifically focusing on radiography, ultrasonography and magnetic resonance imaging. This article will outline the advantages and disadvantages for each modality and illustrate typical radiological findings of common rotator cuff pathologies.