Rotator Cuff Repair With or Without Acromioplasty: A Systematic Review of Randomized Controlled Trials With Outcomes Based on Acromial Type

BACKGROUND

It is unclear whether the use of concomitant acromioplasty during rotator cuff repair (RCR) improves clinical outcomes and whether the outcomes are affected by acromial type.

PURPOSE

To perform a systematic review of randomized controlled trials comparing clinical outcomes of RCR with and without acromioplasty, with a subanalysis of outcomes based on acromial type.

STUDY DESIGN

Systematic review; Level of evidence, 2.

METHODS

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify randomized controlled trials that directly compared outcomes between RCR with versus without acromioplasty. A subanalysis was performed on the studies that provided outcomes based on acromial type. The search phrase used was rotator cuff repair (acromioplasty OR subacromial decompression) randomized. Patients were evaluated based on retear rate, reoperation rate, and patient-reported outcomes (PROs).

RESULTS

Application of inclusion criteria yielded 5 studies (2 studies were level 1, and 3 studies were level 2) including a total of 409 patients, with 211 patients undergoing RCR alone (group A) and 198 patients undergoing RCR with acromioplasty (group B). The mean patient age was 58.5 and 58.3 years in groups A and B, respectively. The mean follow-up time was 52.9 months, and the overall percentage of male patients was 54.1%. The rotator cuff tear size was 20.7 mm and 19.8 mm for groups A and B, respectively. No significant differences were found between groups for any of the PROs at final follow-up. Overall retear rates did not significantly differ between groups based on acromial type. Between 2 studies that measured reoperation rate, a significantly higher reoperation rate was found for the nonacromioplasty group (15%) versus the acromioplasty group (4.1%) (P = .031). One of these studies found that 5 of 9 patients (56%) with a type III acromion in the nonacromioplasty group underwent reoperation compared with 0 of 4 patients with a type III acromion in the acromioplasty group.

CONCLUSION

There is some evidence that acromioplasty during RCR reduces the risk for later reoperation. This may be particularly true for patients with type III acromions, although further studies with larger sample sizes are needed to corroborate these data.

Giant Cell Tumor of the Acromion: Case Report and Literature Review

BACKGROUND/AIM

Giant cell tumor of bone (GCTB) is a locally aggressive neoplasm that typically occurs in the ends (epiphyses) of long bones of young adults. Flat bones are uncommon sites of involvement. Herein, we describe an unusual case of pathologically proven GCT of the acromion.

CASE REPORT

The patient was a 39-year-old woman with no history of trauma who presented with a 3-month history of right posterior shoulder pain. Physical examination revealed mild swelling and tenderness in the posterior aspect of the right shoulder. Plain radiograph showed a purely lytic lesion, suggestive of a bone tumor. Computed tomography demonstrated an intraosseous lytic lesion with associated cortical thinning and lack of periosteal reaction. On magnetic resonance imaging, the lesion exhibited slightly higher signal intensity compared to skeletal muscle on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. Strong enhancement was observed following gadolinium administration. The lesion was treated by extensive curettage with adjuvant therapy comprising ethanol and the remaining cavity was filled with polymethylmethacrylate bone cement. Histologically, the lesion was composed of round or spindle-shaped mononuclear cells admixed with numerous osteoclast-like giant cells. Immunohistochemically, the mononuclear neoplastic cells were diffusely positive for H3.3 G34W. The patient was asymptomatic and there was no evidence of local recurrence or distant metastasis 5 months after surgery.

CONCLUSION

Although rare, acromial GCTB should be considered in the differential diagnosis of posterior shoulder pain, especially in young and early middle-aged adults.

MRI is a Reliable Method for Measurement of Critical Shoulder Angle and Acromial Index

Objective  The objectives of this study are to compare absolute values of acromial index (AI) and critical shoulder angle (CSA) obtained in both radiographs and magnetic resonance image (MRI) of the shoulder; and to compare the interobserver and intra-observer agreement for AI and CSA values measured in these image modalities. Methods  Patients who had medical indication of investigating shoulders conditions through radiographs and MRI were included. Images were taken to two fellowship-trained shoulder surgeons, which conducted measurements of AI and CSA in radiographs and in MRI. Twelve weeks after the first evaluation, a second evaluation was conducted. Inter- and intra-observer reliability was presented as an Intraclass Correlation Coefficient (ICC) and agreement was classified according to Landis & Koch criteria. The differences between two measurements were evaluated using Bland-Altman plots. Results  134 shoulders in 124 subjects were included. Mean intra-observer ICC for CSA in X-rays and in MRI were 0.936 and 0.940, respectively; for AI, 0.908 and 0.022. Mean inter-observer ICC for CSA were 0.892 and 0.752 in X-rays and MRI respectively; for AI, ICC values were 0.849 and 0.685. All individual analysis reached statistical power ( p  < 0.001). Mean difference for AI values measured in X-rays and in MRI was 0.01 and 0.03 for observers 1 and 2, respectively. Mean difference for CSA values obtained in X-rays and MRI was 0.16 and 0.58 for observers 1 and 2, respectively. Conclusion  Both MRI and X-rays provided high intra- and interobserver agreement for measurement of AI and CSA. Absolute values found for AI and CSA were highly correlated in both image modalities. These findings suggest that MRI is a suitable method to measure AI and CSA. Level of Evidence II , Diagnostic Study.

Acromion morphology is associated with glenoid bone loss in posterior glenohumeral instability

BACKGROUND

The acromion morphology in a shoulder with posterior instability differs from that of a shoulder without glenohumeral instability. Specifically, the acromion with a flatter sagittal tilt, greater posterior acromial height, and less posterior coverage is associated with posterior instability. However, the association between acromion morphology and glenoid bone loss (GBL) in the setting of posterior glenohumeral instability has not previously been investigated. The purpose of this study was to determine whether acromial morphology influences the extent or pattern of posterior GBL in a cohort of patients with posterior glenohumeral instability.

METHODS

This multicenter retrospective study identified 89 shoulders with unidirectional posterior glenohumeral instability. Total area GBL was measured using the best-fit circle method on magnetic resonance imaging (MRI). Shoulders were divided into 3 groups: (1) no GBL (n = 30), (2) GBL 0%-13.5% (n = 45), or (3) GBL ≥13.5% (n = 14). Acromion measurements were performed on MRI and included acromial tilt, posterior acromial height, anterior acromial coverage, and posterior acromial coverage.

RESULTS

Patients without GBL had a steeper acromial tilt (58.5° ± 1.4°) compared with those with 0%-13.5% GBL (64.3° ± 1.5°) or GBL ≥13.5% (67.7° ± 1.8°) (P = .004). Patients without GBL also had greater posterior coverage (65.4° ± 1.7°) compared with those with GBL (60.3° ± 1.4°) (P = .015). Posterior acromion height was not significantly different among groups.

CONCLUSION

The results demonstrate that an acromion with a flatter sagittal tilt and less posterior coverage is associated with GBL in the setting of posterior glenohumeral instability. This is important to consider as posterior GBL has been identified as a risk factor for failure of posterior soft tissue-stabilizing procedures.

Octogenarian With Acromion Stress Fracture Nonunion With Reverse Total Shoulder Prosthesis Reconstructed With Plates and Screws: A Case Report

An 85-year-old male underwent open reduction and internal fixation (ORIF) for a displaced acromion stress fracture that occurred two years prior. The complete fracture occurred two months after an ipsilateral reverse total shoulder arthroplasty (RTSA). Four weeks after his RTSA, the pain was felt at the posterior-superior shoulder with activities of his daily living as a rancher, reflecting non-compliant use. A stress fracture was suspected but not detected radiographically. Four weeks later, higher pain occurred after he lifted a hay bale, and a displaced basilar acromion fracture was detected. Non-operative management spanned 20 months, which he ultimately deemed unacceptable because of pain with minor activities. ORIF was then done. Approximately 10 months after the ORIF surgery, both plates sustained fatigue breakage; however, the fracture consolidated, and his pain remained low. He is the oldest patient described to ultimately have a successful acromion fracture ORIF and only the third reported acromion fracture ORIF in octogenarians following RTSA. We report the ORIF technique, its good outcome, and a literature review of elderly patients who had ORIF for this problem.

[Association of morphological variables of acromion type with rotator cuff lesions by nuclear magnetic resonance]

INTRODUCTION

the acromion is a small portion of the scapula that extends towards the anterior region from the spine of the scapula. Traditionally, the acromion is classified by the shape of its inferior surface in a sagittal plane. Acromial morphology has been found to be related to rotator cuff injury.

OBJECTIVE

to determine the association between the type of acromion with a higher incidence of rotator cuff rupture. Study population: patients who come to the Traumatology and Orthopedics Service of a third level hospital at Monterrey, Mexico, due to a painful shoulder and who have undergone a simple magnetic resonance of the shoulder.

MATERIAL AND METHODS

a cross-sectional, retrospective and descriptive study was carried out, in which 273 magnetic resonance studies were reviewed in patients who met the inclusion criteria. The type of acromion was reported according to the morphological classification in type I to IV and the state of the rotator cuff: without rupture, partial rupture or complete rupture, making a comparison between right and left shoulder.

RESULTS

in this study we found a value of p = 0.473 which concludes that there is no relation between the type of acromion and the injury of the rotator cuff.

CONCLUSION

in the present study, unlike what has been published in the literature, it was found that type II acromion was the one that was associated in most cases with a rotator cuff tear.

Effect of Reverse Shoulder Arthroplasty Humeral Component Retroversion on Acromial Strain

INTRODUCTION

Acromion and scapular spine stress fractures can be catastrophic complications following reverse shoulder arthroplasty (RSA). A variety of host, implant, and technical factors have been identified that increase the risk of this complication. The glenoid component in particular has been closely evaluated for its impact on rates of stress fractures following RSA. The goal of this biomechanical study is to evaluate if humeral stem version has an impact on acromion and scapular spine strain after RSA.

METHODS

Eight cadaveric specimens were tested on a custom dynamic shoulder frame. Commercially available RSA components were implanted with the humeral component inserted in 0 degrees of retroversion. Acromion and scapular spine strain were measured at 0, 30, and 60 degrees of abduction using strain rosettes secured to the acromion and scapular spine in the typical locations for Levy Type 2 and Type 3 stress fractures, respectively. The humeral stem was then removed and reimplanted in 30 degrees of retroversion and the measurements were repeated. Student t-test was performed to analyze the relationship between humeral stem version and acromion and scapular spine strain at various abduction angles.

RESULTS

Strain at the both the acromion and scapular spine were found to have no significant difference at any abduction angle when comparing 0- and 30-degree version of the humeral stem. With 0-degree and 30-degree versions pooled together, there is significantly lower acromion and scapular spine strain at 60 degrees of abduction when compared to 0 degrees of abduction [Strain at 0 degrees abduction - strain at 60 degrees abduction: Acromion 313.1 μꜪ; p = 0.0409, Scapular spine 304.9 μꜪ; p.= 0.0407]. There was no significant difference in strain at either location when comparing 0 degrees of abduction to 30 degrees of abduction and when comparing 30 degrees of abduction to 60 degrees of abduction.

CONCLUSIONS

This biomechanical study found no significant difference in scapular spine and acromion strain after RSA when comparing variations in humeral stem version. There does appear to be lower strain at both the acromion and scapular spine at 60 degrees of abduction when compared to 0 degrees of abduction regardless of stem version.

Reliability of Bigliani's Classification using Magnetic Resonance Imaging for Determination of Acromial Morphology

Introduction

Bigliani classification is used for determination of acromial morphology, but poor inter-observer reliability has been reported on conventional radiographs. This study aims to assess inter- and intra-observer reliability using magnetic resonance imaging (MRI).

Materials and methods

Forty consecutive patients diagnosed with subacromial impingement syndrome were included to study. All subjects underwent standard shoulder MRI scan and acromial shape was evaluated by nine observers of different level of expertise (three attending surgeons, three senior orthopaedic residents and three radiologists). A second set of evaluation was performed in order to assess intra-observer reproducibility. Kappa (κ) coefficient analyses both for interobserver reliability and intra-observer reproducibility were then performed.

Results

Overall inter-observer agreement among nine observers was fair (κ=0.323). κ values for all 4 individual types ranged from 0.234 to 0.720 with highest agreement for type 4 and lowest agreement for type 3. Second evaluation did not result with an increase of inter-observer agreement (κ=0.338, fair). The κ coefficients for intra-observer reproducibility of nine observers ranged from 0.496 to 0.867. Overall intra-observer reproducibility was substantial. Comparison of inter- and intra-observer reliability among three groups showed no significant difference (p=0.92 and 0.22, respectively).

Conclusion

Results showed that MRI did not show superior reliability compared to conventional radiographs. Moreover, inter- and intra-observer agreement did not differ between observers of different level of expertise. Findings of present study suggest that despite a sophisticated imaging modality like MRI, Bigliani's classification apparently lacks accuracy and additional criteria, or different assessment methods are required to assess acromial morphology for clinical guidance.

The correlation between acromial osteolysis and acromion types in the treatment of acromioclavicular joint dislocation with hook plate

This study aimed to radiologically evaluate the effect of hook plates used in the treatment of acromioclavicular joint (ACJ) dislocations on the development of subacromial osteolysis (SAO) according to acromion types. A total of 43 patients with mean age of 38.5 (19-77) years who were diagnosed with AC dislocation and applied neutral clavicular hook plate between 2013 and 2020 were retrospectively evaluated. Acromion types were determined by measuring acromion slope angle on lateral shoulder radiography and 3-dimensional (D)-CT of the patients. Presence of SAO was classified according to the severity of erosion in the subacromial region (grade I: minimal osteolysis, grade II: subacromial erosion <2 mm, grade III: subacromial erosion >2 mm, grade IV: cut-through of the acromion) on postoperative 3D - CT and correlation with acromion types was analyzed. Incidence of SAO was significantly higher among type 1 acromion compared to type 2 and type 3 acromion (P = .003). While osteolysis was observed in 21 patients, no osteolysis was observed in 22 patients. Osteolysis occurred in all patients with type 1 acromion, 7 patients with type 2 acromion, and 5 patients with type 3 acromion. Since the hook tip in the sagittal plane passes posterior to the center of the acromion and the concavity of the subacromial surface is inadequate in the type 1 acromion, we believe that the increased pressure applied by the hook tip on the subacromial cartilage increases the risk of SAO. We predict that the use of hook plates with an angle of 15-20 degrees, similar to the patient's AC angle, rather than neutral hook plate, will reduce the risk of osteolysis in patients with type 1 acromion.

Acromial fractures following reverse shoulder arthroplasty: the role of the acromial morphology and a comparison of clinical outcomes

BACKGROUND

The purpose was to evaluate the relationship between acromial morphology and the location of acromial fractures following reverse shoulder arthroplasty and determine whether fracture location and displacement impact clinical outcomes.

METHODS

We performed a multicenter retrospective review of reverse shoulder arthroplasties complicated by acromial fractures. Radiographs were compared to determine the differences in acromial morphology, as well as fracture orientation and pattern, between patients with Levy type I (n = 17) and Levy type II (n = 25) fractures. Patients with a minimum of 2 years' follow-up were selected to examine the association between clinical outcomes and fracture location and displacement. Twenty-two patients were stratified based on whether they achieved the minimal clinically important difference (MCID) in the American Shoulder and Elbow Surgeons score (20 points). The groups were then compared regarding fracture location and displacement using measurements such as the acromiohumeral distance.

RESULTS

The Levy type I group had a higher acromial slope than the Levy type II group (127° vs. 117°, P < .001). Levy type I fractures had a transverse pattern occurring in the coronal plane, whereas Levy type II fractures had an oblique pattern occurring in the sagittal plane (P < .001). At final follow-up, 12 of 22 patients (55%) achieved the MCID. Those who did not achieve the MCID had more displaced fractures including a lower acromiohumeral distance (8 mm vs. 20 mm, P = .007). There was no difference in the distribution of Levy type I and type II fractures based on the MCID cutoff (P = .093).

CONCLUSION

An increased acromial slope is associated with transverse fractures in the Levy I region, whereas a lower acromial slope is associated with oblique fractures in the Levy II region. Overall, 55% of patients achieved the MCID at mid-term follow-up. The outcomes of those who did not achieve the MCID became worse postoperatively, and this was associated with increased fracture displacement.

Mechanical complications and fractures after reverse shoulder arthroplasty related to different design types and their rates: part I

The initial reverse shoulder arthroplasty (RSA), designed by Paul Grammont, was intended to treat rotator cuff tear arthropathy in elderly patients. In the early experience, high complication rates (up to 24%) and revision rates (up to 50%) were reported.The most common complications reported were scapular notching, whereas clinically more relevant complications such as instability and acromial fractures were less commonly described.Zumstein et al defined a 'complication' following RSA as any intraoperative or postoperative event that was likely to have a negative influence on the patient's final outcome.High rates of complications related to the Grammont RSA design led to development of non-Grammont designs, with 135 or 145 degrees of humeral inclination, multiple options for glenosphere size and eccentricity, improved baseplate fixation which facilitated glenoid-sided lateralization, and the option of humeral-sided lateralization.Improved implant characteristics combined with surgeon experience led to a dramatic fall in the majority of complications. However, we still lack a suitable solution for several complications, such as acromial stress fracture. Cite this article: EFORT Open Rev 2021;6:1097-1108. DOI: 10.1302/2058-5241.6.210039.

Acromion types and morphometric evaluation of painful shoulders

BACKGROUND

Due to its many variations, the scapula is among the most frequently examined bones. Especially the acromion can be of different shapes and sizes. Measurements of the morphometric structures in the shoulder joint make it easier to explain the cause of the various shoulder problems. The objective of this study is putting emphasis on the importance of acromion types, os acromiale presence and acromial morphometric measurements in the aetiology and diagnosis of shoulder pain.

MATERIALS AND METHODS

A retrospective study, based on 100 patients of both genders who presented with the complaints of shoulder pain and underwent magnetic resonance imaging, was conducted. Within this scope, types of acromion, slope of acromion, length of acromion, length of coracoid process, the distance between acromion and coracoid process, lateral acromial angle (LAA), critical shoulder angle (CSA), acromial index (AI) and acromiohumeral distance were measured. The data were analysed considering the gender and acromion types and the presence of os acromiale is investigated.

RESULTS

The most common acromion was type II (curved) (frequency rate 62%) while the rate of type I (flat) and type III (hooked) acromions were 21% and 17%, respectively. The length of acromion and coracoid process were found to be significantly longer in males, while no significant difference between genders in terms of the distance between acromion and coracoid process were observed. Furthermore, while negative correlation between LAA and AI as well as LAA and CSA were observed; positive correlation between AI and CSA was found. In addition, there was negative correlation between slope of acromion and acromiohumeral distance. Besides, acromiohumeral distance was significantly higher in males. Regarding the presence of os acromiale, it was observed in 3 women out of 59 and 2 men out of 41, which indicated no significant difference between genders.

CONCLUSIONS

It is evaluated that the morphometric measurement is of importance in contributing clinically in distinguishing the problems that may occur according to gender and acromion types.

Does Preservation of Coracoacromial Ligament Reduce the Acromial Stress Pathology Following Reverse Total Shoulder Arthroplasty?

Introduction

Acromial pathologies (AP), such as acromial stress reaction (ASR), acromial stress occult fracture (ASOF), and acromial stress fracture (ASF), are known as complications that deteriorate the clinical score and patient satisfaction after reverse total shoulder arthroplasty (RSA). Several factors that increase stress on the acromion have been reported as risk factors for AP, but this is also unclear. Thecoracoacromial ligament (CAL) is a structure that distributes the stress loading on such an acromion, although its importance has been mentioned, there is a lack of research. Therefore, we investigated the incidence of AP according to the preservation of the CAL and whether it is a risk factor.

Methods

The study was retrospectively conducted on patients who underwent RSA from 2016 and 2018. Patients with CAL transection was classified into group 1 and CAL preservation was classified into group 2. ASR and ASOF were identified through symptoms and ultrasound, and ASF identified through simple radiograph or computed tomography. The incidence of AP in each group was checked and compared.

Results

Of the total of 265 patients. Among 197 cases of group 1, 21 cases of ASR(10.7%), 28 cases of ASOF (14.2%),10 cases of ASF (5.1%), and 59 cases of total AP (29.4%). Among 68 cases in group 2, 2 cases (2.9%) of ASR, 6 cases of ASOF(8.8%), 1 case of ASF (1.5%), and 9 cases of total AP (13.2%). It was confirmed that ASR and ASOP were significantly decreased in the group preserving CAL. (P = .008)

Conclusion

In the case of preservation of CAL during surgery, it was confirmed that the incidence of ASR, ASOF was reduced. Therefore, preservation of CAL can be regarded as a modifiable risk factor that can reduce the risk of AP by distributing the stress applied to acromion after RSA surgery.

Three-dimensional evaluation of scapular morphology in primary glenohumeral arthritis, rotator cuff arthropathy, and asymptomatic shoulders

BACKGROUND

Recently, the 3-dimensional (3D) morphology of the coracoacromial complex in nonpathologic shoulders has been described. The aim of this study was to evaluate and compare the coracoacromial complex in pathologic shoulders (glenohumeral osteoarthritis [GHOA] and cuff tear arthropathy [CTA]) and nonpathologic shoulders.

METHODS

A 3D computed tomography reconstruction of 205 scapulae was performed (49 with GHOA, 48 with CTA, and 108 in normal shoulders [NL]). Subsequently, the center of the glenoid circle and several points at the coracoid, acromion, and glenoid were determined. The distances between these points and the rotation of the coracoacromial complex were calculated, and the acromion-glenoid angle was measured.

RESULTS

The acromial overhang was significantly different between the NL (37 mm) and CTA (35 mm) groups (P = .045), as well as between the CTA and GHOA groups (33 mm) (P = .010). The acromion-glenoid angle showed a significant difference between the NL (mean, 50°) and GHOA (mean, 42°) groups (P < .001) and between the CTA (mean, 50°) and GHOA groups (P < .001). Furthermore, a significant difference was found in the acromial height, which was larger in the GHOA group (36 mm) than in the CTA group (30 mm) (P < .001) or NL group (30 mm) (P < .001).

CONCLUSION

This 3D morphologic study showed that the acromial part of the complex was turned more posteriorly in both pathologic groups. Furthermore, we found the coracoacromial complex to be more cranial to the glenoid center in the GHOA group. Finally, a significant difference in the lateral overhang of the coracoacromial complex was observed between the 3 groups. The NL group had a larger overhang than the CTA group, and the CTA group in turn had a larger overhang than the GHOA group.

A Simple Bone Cyst of the Acromion: Case Report

Simple bone cysts rarely occur in the scapula, and, to our knowledge, they have not been reported in the acromion. In the present report, we present the case of a 24-year-old female patient who was successfully treated by curettage and grafting using xenografting. No recurrence findings were observed during the follow-up six months postoperatively, the patient had recovered full range of motion, and she was able to perform all routine activities satisfactorily.

Morphology of the Undersurface of the Anterolateral Acromion and Its Relationship to Surrounding Structures

Background:

A better understanding of the morphology underneath the acromion is needed to prevent complications after arthroscopic subacromial decompression. The precise correlations between the morphologic features underneath the acromion and the surrounding structures including the attachment of the coracoacromial ligament (CAL) and the origin of the deltoid middle head have not yet been determined in the absence of artifacts on the bony surface caused by dissection techniques. Moreover, anatomic findings in previous studies using only older-aged cadavers or dried bones may not reflect the morphologic features of younger and healthy specimens.

Purpose:

To characterize the anterolateral structures morphologically in the inferior aspect of the acromion, assess the relationships of these structures with surrounding structures without dissection artifacts on the bony surface, and verify the cadaveric data in the asymptomatic shoulders of living middle-aged patients.

Study Design:

Descriptive laboratory study.

Methods:

We initially analyzed the relationship between the morphology of the anterolateral structures and surrounding structures in 18 cadaveric shoulders (mean age, 81.8 years), 15 of which were subjected to macroscopic investigation of the CAL attachment and 3-dimensional micro—computed tomography investigation with radiopaque markers and 3 of which were subjected to histologic examination. We also analyzed the morphology underneath the anterolateral acromion in 24 asymptomatic shoulders of middle-aged patients (mean age, 54.8 years) to verify the cadaveric data. In both the cadaveric shoulders and the asymptomatic shoulders of live patients, the long axis, width, and height of the anterolateral prominence were measured by use of 3-dimensional CT imaging.

Results:

In cadavers, the anterolateral prominence underneath the acromion corresponded to the attachment of the CAL. Histologic evaluation revealed that the CAL was continuous to the deep layer of the deltoid middle head in the lateral acromion. The study in asymptomatic shoulders of middle-aged patients revealed bony prominences similar to those observed in cadavers.

Conclusion:

The anterolateral prominence, which corresponds to the attachment of the CAL below the acromion, may be a native structure below the acromion. Moreover, the CAL is continuous to the deep layer of the deltoid middle head in the lateral acromion.

Os Acromiale in Reverse Total Shoulder Arthroplasty: A Cohort Study

Background:

Increased passive deltoid tension after reverse total shoulder arthroplasty (RTSA) potentially leads to displacement or tilting of a preexisting os acromiale.

Purpose:

To analyze patients with an os acromiale who underwent RTSA and compare their outcomes and complications with a matched control group without an os acromiale.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

In this study, 45 shoulders in 42 patients with an os acromiale (cases) were matched to 133 patients without os acromiale (controls) who underwent RTSA between 2005 and 2016. The mean follow-up was 52 ± 32 months. Matching criteria included sex, type of surgery, duration of follow-up, and age. The Constant score (CS), Subjective Shoulder Value (SSV), and radiological outcomes were assessed postoperatively at 1-year, 2-year, and final follow-up visits.

Results:

The mean CS, SSV, and range of motion improved from preoperative levels to the final follow-up in both groups (P < .01). Patients with an os acromiale had a relative CS of 70 ± 23 versus 76 ± 21 points (P = .15) and an SSV of 70 ± 30 versus 73 ± 24 (P = .52) compared with controls at the final follow-up visit. Patients with an os acromiale had significantly decreased active flexion of 104° ± 33° versus 114° ± 33° (P = .03) at 1 year and active abduction of 103° ± 37° versus 121° ± 38° at 2 years postoperatively (P = .02). A postoperatively painful os acromiale was found in 12 cases (27%) and spontaneously resolved in 8 cases after a mean of 33 months (range, 12-47 months; P = .04).

Conclusion:

RTSA reliably restores patient satisfaction despite the presence of an os acromiale, with a slightly impaired range of motion. Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients, but this resolves spontaneously over time in the majority of patients.

Influence of Acromial Morphologic Characteristics and Acromioclavicular Arthrosis on the Effect of Platelet-Rich Plasma on Partial Tears of the Supraspinatus Tendon

OBJECTIVE. The purposes of this study were to determine the medium-term effect of ultrasound-guided infiltration of platelet-rich plasma (PRP) on partial tears of the supraspinatus tendon (SST) and to identify prognostic indicators of an unfavorable outcome. SUBJECTS AND METHODS. Over a period of 4 years, patients with a partial SST tear smaller than 1.5 cm referred for ultrasound-guided PRP infiltration (1 mL) for shoulder pain lasting more than 3 months were recruited consecutively. MRI was used to analyze the type of acromion and presence of acromioclavicular (AC) arthrosis. Primary (size of the tear and associated bursitis) and secondary (mobility and pain) results were collected at 3 months. RESULTS. The study included 128 patients (66 men, 62 women; mean age, 48.3 years; range, 20-59 years). At 3 months, favorable evolution of the tear repair was recorded in 71.1% (91/128) of patients and resolution of bursitis in 66.7% (42/63). Changes in tear size had large effect sizes (Cohen d ≥ 1.16), as did pain and shoulder mobility (Cohen d ≥ 0.95). The strongest predictors of unfavorable evolution of tear and bursitis were type 3 acromion and types 1 and 2 acromion with AC arthrosis (p < 0.001; β = 20.412). CONCLUSION. Ultrasound-guided PRP infiltration of partial tears of the SST relieves pain and improves shoulder mobility, but its effect on the size of the tear is influenced by the morphologic characteristics of the acromion and the presence of AC arthrosis. The effect of PRP is insufficient in patients with a type 3 acromion or severe AC arthrosis.

Extended Curettage and Fibular Grafting in Enchondroma of the Acromion

We report the case of a six-year-old male child with progressive pain and swelling of the right shoulder for six months. On examination, there was a 7x7 cm globular, tender swelling with firm consistency over the posterolateral corner of the right shoulder. Radiographs showed an expansile lytic lesion in the acromion process of the scapula. Biopsy showed lobules of hypocellular cartilage separated by fibroconnective stroma suggestive of an enchondroma. Extended curettage and fibular bone grafting of the lesion was done. At one-year follow-up, the patient was symptom-free and had full, painless shoulder range of motion. To the best of our knowledge, there is no published record of an enchondroma of the acromion.

Os acromiale: systematic review of surgical outcomes

BACKGROUND

The literature is unclear as to the optimal surgical management of a symptomatic os acromiale that has failed nonoperative treatment. Surgical options include excision, acromioplasty, and open reduction and internal fixation. The purpose of this study is to summarize the described methods and compare their reported outcomes with the goal to provide direction on how to surgically manage os acromiale.

METHODS

We performed a systematic review of the current medical literature. Fifteen studies met all the inclusion criteria. Two hundred eleven total subjects (220 shoulders) underwent surgical treatment for a symptomatic os acromiale. There were 140 men and 71 women with a mean age of 49.6 ± 9.1 years. The mean follow-up duration was 40 ± 11.6 months. Surgical techniques used in the included studies were excision, acromioplasty, and open reduction with internal fixation. Concurrent surgical procedures performed were also included.

RESULTS

Meso-os acromiale was the most common type (167 cases, 94.4%). The most common surgical technique was internal fixation (135 cases, 60.8%), with screw fixation being the majority (76 cases, 56.3%). Excision (65 cases, 29.3%) was the second most used technique. The most common concurrent surgical procedure performed was rotator cuff repair (125 cases, 56.3%), followed by distal clavicle excision (31 cases, 14%).

CONCLUSIONS

All surgical techniques employed resulted in improvement in postsurgical clinical outcomes without any technique demonstrating superior results. Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes.

Correlation of acromial morphology in association with rotator cuff tear: a retrospective study

Purpose

There have been many studies that have attempted to correlate radiographic acromial characteristics with rotator cuff tears, but the results have not been conclusive. Rotator cuff tears (RCT) are the common aetiology of shoulder pain. We assessed the association of rotator cuff tears with commonly used radiographic parameters of acromial morphology and their different radiographic characteristics.

Material and methods

From a retrospective study of 98 patients, we characterised acromial type and measured acromial thickness (AT), critical shoulder angle (CSA), lateral acromial angle (LAA), acromiohumeral distance (AHD), and acromion index (AI) on a 1.5T MRI, from 68 patients with partial or full-thickness supraspinatus tendon tears and 30 controls without tears.

Results

Out the 68 patients with rotator cuff tear, supraspinatus was the most commonly affected tendon, with 86% (59) cases showing abnormalities. The average age of the patients was 45.11 ± 21.45 years with male dominance (80%). Partial tears of rotator cuff were more common than complete tears. Forty-eight cases showed partial tears in supraspinatus as compared to 11 cases of complete tears. The acromial type did not show any correlation with any particular cuff lesion. The AT and AI of controls were significantly smaller than cuff-tear patients. The LAA of cuff-tear patients was significantly different from that of control patients. The impingement patients demonstrated a significantly greater acromial thickness, larger CSA, decreased AHD, and decreased LAA than their control counterparts.

Conclusions

A higher prevalence of rotator cuff tears and impingement associated with low lateral acromial angle, larger CSA and decreased AHD was observed. AT and AI have a direct correlation with rotator cuff tear.

Safe zone for lateral pin placement for external fixation of the distal humerus

External fixation is a common, efficient technique used for humeral shaft stabilization and elbow fractures. There are reports of radial nerve injuries associated with this procedure. In this study, we investigated the course and variability of the radial nerve along the lateral humerus in relation to the elbow joint to determine a relatively safe zone for lateral pin placement in external fixation. Twenty upper extremities from 10 cadavers were studied. The nerve branches and course of the radial nerve along the lateral humerus were carefully dissected. Straight lines (a, b, and c) were made connecting three landmarks (the acromion, coracoid process, and anterior wall of the axilla) in the proximal upper extremity to the lateral condyle (LC) of the humerus; their intersections with the radial nerve (A, B, and C) were marked. We analyzed whether the intersection positions were correlated with the connecting line lengths. The mean lengths of the connecting lines were (a) 27.24 ± 2.57, (b) 26.18 ± 2.79, and (c) 20.95 ± 1.44 cm; the distance between the intersection points and the LC of the humerus were (Aa) 7.56 ± 1.31, (Bb) 6.90 ± 2.27, and (Cc) 5.01 ± 0.83 cm; and the measured intersection points of the radial nerve in the lateral aspect of the humerus were (A) 18.48%-34.82%, (B) 13.48%-40.00%, and (C) 19.27%-28.05% of the lengths of lines a, b, and c, respectively. Our data provide a more reliable reference to predict the course of the radial nerve on the lateral humerus and define a safe zone for pin placement. Clin. Anat., 33:637-642, 2020. © 2019 Wiley Periodicals, Inc.

Os acromiale: a review of its incidence, pathophysiology, and clinical management

An os acromiale occurs when any of the primary ossification centres of the acromion fail to fuse with the basi-acromion. It is present in approximately 8% of individuals, and whilst the majority of these individuals are unaffected it can cause significant pain and disability. It can impact seemingly unrelated surgical intervention in the region such as subacromial decompression and reverse shoulder arthroplasty. A painful os acromiale can be both a diagnostic challenge, and difficult to manage. There remain a wide variety of surgical practices with variable outcomes achieved. We present an evidence-based discussion of the surgical techniques described to date in the literature, alongside a comprehensive review of the incidence and pathophysiology of os acromiale.

This review was written after a comprehensive analysis of the literature to date relating to os acromiale. Particular focus was given to material examining surgical management techniques, and the condition’s incidence across different population groups.

Open reduction and internal fixation using cannulated screws, or tension band wiring have superior outcomes in the literature in the treatment of symptomatic os acromiale. There may be a biomechanical advantage of combining the two techniques. Preservation of large anterior deltoid attachment is necessary, with consideration being given to the local blood supply. There is likely no additional benefit from iliac crest vs local bone grafting. Research in this area remains of a low evidence level with small samples sizes. Appropriately powered clinical research of a higher-level evidence methodology is needed in order to differentiate further in the choice of surgical intervention.

Cite this article: EFORT Open Rev 2019;4:525-532. DOI: 10.1302/2058-5241.4.180100

Voluntary acromioclavicular joint dislocation: a case report and literature review

Voluntary glenohumeral dislocations have been reported in academic literature; however, voluntary dislocations of the acromioclavicular joint are rare, with four cases previously reported in published literature. We present a case of an adolescent female with bilateral, atraumatic acromioclavicular joint dislocation who ultimately was treated with arthroscopic reconstruction of the coracoclavicular ligament. The case is discussed in addition to a review of previously reported cases of voluntary acromioclavicular joint dislocations. Treatment methods in each of the four previously reported cases are discussed with recommendation for surgeons that may encounter this rare shoulder problem in future patients.

Grammont Award 2018: Scapular fractures in reverse shoulder arthroplasty (Grammont style): prevalence, functional, and radiographic results with minimum 5-year follow-up

BACKGROUND

Scapular fractures after reverse shoulder arthroplasty (RSA) are an increasingly reported complication. Information is missing regarding midterm to long-term follow-up consequences. The aim of this study was to determine the rate of scapular fracture (acromial base and spine) after Grammont-style RSA and to report functional and radiographic results of patients with a minimum 5-year follow-up.

MATERIALS AND METHODS

We retrospectively reviewed 1953 Grammont-style RSAs in 1745 patients in a multicenter study. Of these, 953 patients (1035 RSAs) had minimum 5-year follow-up for functional and radiographic assessment (anteroposterior and scapular Y views.

RESULTS

Twenty-six patients (1.3%) had sustained a scapular fracture; of these, 19 (10 acromial base and 9 spine fractures) had minimum 5-year follow-up and were reviewed at a mean follow-up of 97 months. Three patients (15.8%) were diagnosed at the last follow-up after an undiagnosed fracture. There were 3 traumatic cases (15.8%) and 13 (68.4%) without antecedent trauma. These 16 patients underwent nonoperative treatment. The fracture was healed in 8 (4 acromion and 4 spine). The average active forward elevation was 109° (range, 50°-170°), and the Constant score was 47.0 points (range, 8-81 points).

CONCLUSIONS

Scapular fractures after Grammont-style RSAs are rare (1.3%) but remain a concern. These fractures occur mainly in the early postoperative 6 months. Immobilization with an abduction splint frequently resulted in nonunion or malunion. Final functional outcomes are poor regardless of acromial or spine fracture compared with primary RSA without fracture.

Symptomatic pseudoarthrosis secondary to a stress fracture of the acromion

Fractures of the acromion are uncommon clinical entities, and stress fractures are even more rare, with few cases reported. Due to their rarity, stress fractures are often misdiagnosed. Here, we report a case of an elderly patient with an acromion stress fracture, which was overlooked, resulting in nonunion followed by the displacement of the distal portion of the acromion. The purpose of this report was to discuss this rare fracture, highlighting the importance of an accurate evaluation of radiological imaging as well as clinical data. (www.actabiomedica.it).

Increased scapular spine fractures after reverse shoulder arthroplasty with a humeral onlay short stem: an analysis of 485 consecutive cases

BACKGROUND

Scapular stress fractures after reverse shoulder arthroplasty (RSA) are a potentially serious complication with modern lateralized and onlay implants. The aim of this study was to report the scapular spine stress fracture rate after RSA with an onlay, 145° humeral stem, analyzing potential fracture risk factors and clinical outcomes in a large cohort of patients.

METHODS

A consecutive series of 485 RSAs were implanted with the Aequalis Ascend Flex stem. Data collection included preoperative and postoperative clinical and radiographic assessment findings (rotator cuff Goutallier grade; Hamada, Walch, and Favard classifications; range of motion; Constant score) and perioperative data. Patients with a scapular spine fracture following RSA were matched with nonfracture control patients, and preoperative variables were tested to determine whether they were predictive of a scapular spine fracture.

RESULTS

A scapular spine fracture following RSA occurred in 21 patients (4.3%), with a mean time to diagnosis of 8.6 months (range, 1-34 months). No preoperative factor was found to be a significant predictor of scapular spine fracture. Both groups showed significant improvements in active mobility measurements and Constant scores from preoperatively to final follow-up (P < .001). The control group scored significantly better than the scapular spine fracture group regarding the Constant score and forward flexion.

CONCLUSION

Scapular spine fractures have shown an increased prevalence after onlay-design RSA. This series was not able to link any clear risk factors. Functional results are limited, regardless of the fracture management.

The critical acromial point: the anatomic location of the lateral acromion in the critical shoulder angle

BACKGROUND

Acromioplasty has been proposed as a means of altering elevated critical shoulder angles (CSAs). We aimed to localize the critical acromion point (CAP) responsible for the acromial contribution of the CSA and determine whether resection of the CAP can alter the CSA to a normal range.

METHODS

The CAP and 3-dimensional (3D) CSAs were determined on 3D computed tomography reconstructions of 88 cadaveric shoulders and compared with corresponding CSAs on digitally reconstructed radiographs. The position of the CAP was fluoroscopically isolated in 20 of these specimens and the resulting fluoroscopic CSA compared with the corresponding 3D CAP and 3D CSA. We investigated the CSA before and after a virtual acromioplasty of 2.5 and 5 mm at the CAP in specimens with a CSA greater than 35°.

RESULTS

The mean CAP was 21% ± 10% of the acromial anterior-posterior length from the anterolateral corner. There was no difference between the mean 3D CSA and the CSA on digitally reconstructed radiographs (32° vs 32°, P = .096). No difference between the mean fluoroscopic CSA and 3D CSA was found (31° vs 31°, P = .296). A 2.5-mm acromial resection failed to reduce the CSA to 35° or less in 7 of 13 shoulders, whereas a 5-mm resection reduced the CSA to 35° or less in 12 of 13.

CONCLUSION

The CAP was localized to the anterolateral acromial edge and was easily identified fluoroscopically. A 5-mm acromial resection was effective in reducing the CSA to 35° or less. These data can guide surgeons in where and how to alter the CSA if future studies demonstrate a clinical benefit to surgically modifying this radiographic parameter.

Acromion and glenoid shape: Why are they important predictive factors for the future of our shoulders?

The shape of the acromion differs between patients with degenerative rotator cuff tears and individuals without rotator cuff pathology.It can be assessed in the sagittal plane (acromion type, acromion slope) and in the coronal plane (lateral acromion angle, acromion index, critical shoulder angle).The inter-observer reliability is better for the measurements in the coronal plane.A large lateral extension (high acromion index or high critical shoulder angle) and a lateral down-sloping of the acromion (low lateral acromion angle) are associated with full-thickness supraspinatus tears.The significance of glenoid inclination for rotator cuff disease is less clear.The postulated patho-mechanism is the compression of the supraspinatus tendon between the humeral head and the acromion. Bursal side tears might be caused by friction and abrasion of the tendon. Articular side tears could be due to impairment of the gliding mechanism between tendon fibrils leading to local stress concentration. Further research is needed to understand the exact pathomechanism of tendon degeneration and tear. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160076. Originally published online at www.efortopenreviews.org.

Is There an Association Between the "Critical Shoulder Angle" and Clinical Outcome After Rotator Cuff Repair?

BACKGROUND

Variations in scapular morphology have been associated with the development of atraumatic rotator cuff tears (RCTs). The critical shoulder angle (CSA) accounts for both glenoid inclination and lateral extension of the acromion. The impact of the CSA on outcomes after rotator cuff repair (RCR) has not been investigated previously.

HYPOTHESIS

Our hypothesis was that individuals with smaller CSAs will have better patient-reported outcome scores over time compared with those with larger CSAs. Theoretically, a smaller CSA minimizes the biomechanical forces favoring superior translation of the humeral head, which may be advantageous after RCR. This is the first study to examine the relationship between the CSA and clinical outcomes after RCR.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Fifty-three patients (mean age, 61 years) with atraumatic full-thickness RCTs who underwent arthroscopic RCR were prospectively evaluated. Demographic data as well as the Western Ontario Rotator Cuff Index (WORC) score, American Shoulder and Elbow Surgeons (ASES) score, and a visual analog scale (VAS) for pain were prospectively collected at various time points up to 24 months postoperatively. Statistical analysis included longitudinal multilevel regression modeling to investigate the association between the CSA and the WORC, ASES, and VAS scores.

RESULTS

The overall clinical outcome, as measured by the WORC, ASES, and VAS, improved significantly (P < .0001). Controlling for demographic and clinical characteristics, a multilevel regression analysis demonstrated that the CSA was not a significant independent predictor for change in WORC (P = .581), ASES (P = .458), or VAS (P = .859) scores at 24 months after arthroscopic RCR. Interobserver and intraobserver reliability for CSA measurements resulted in interclass correlation coefficients of 0.986 and 0.982, respectively (P < .001), indicating excellent agreement.

CONCLUSION

The CSA did not appear to be a significant predictor of patient-reported outcomes after arthroscopic repair of atraumatic full-thickness RCTs.

Acromial and scapular spine fractures after reverse total shoulder arthroplasty

Acromial and scapular spine fractures after reverse total shoulder arthroplasty occur predominantly as a result of bony insufficiency secondary to patient and intra-operative technical factors. The spectrum of the pathology can range from a stress reaction to an undisplaced or displaced fracture. Prompt diagnosis of these fractures requires a high suspicion in the postoperative patient with a clinical presentation of acute onset of pain along the acromion or scapular spine and/or deterioration of shoulder function. Conventional shoulder radiographs are frequently unreliable in identifying these fractures, especially if they are undisplaced. Computed tomography (CT) and/or single photon emission computed tomography/CT scans are useful imaging modalities for obtaining a definitive diagnosis. Early diagnosis and non-operative treatment of a stress reaction or undisplaced fracture is essential for preventing further displacement and potential disability. The management of displaced fractures is challenging for the orthopaedic surgeon as a result of high rates of mal-union or non-union, decreased functional outcomes, and variable results after open reduction and internal fixation. Strategies for preventing these fractures include optimizing the patient's bone health, correct glenoid baseplate screw length and position, and avoiding excessive deltoid tension. Further research is required to identify the specific patient and fracture characteristics that will benefit from conservative versus operative management.

Does scapular morphology affect the integrity of the rotator cuff?

BACKGROUND

Current evidence suggests that distinct scapular morphologies may predispose patients to a rotator cuff tear. The objective of this longitudinal study was to evaluate the relationship between symptomatic degenerative cuff tears and different radiographic acromial characteristics, including acromion shape, indices (acromial index [AI], critical shoulder angle [CSA]), and acromial spur.

METHODS

We divided 166 patients into 3 groups matched for age and sex: group 1, degenerative full-thickness tear; group 2, partial thickness bursal tear; and group 3, normal cuff. Patients were evaluated with standard radiographs and ultrasonography.

RESULTS

The presence of an acromial spur was strongly associated with a full-thickness cuff tear (odds ratio, 3.5; P = .001). AI and CSA revealed a statistically significant difference between means of group 1 (P = .006) and group 3 (P < .001). There was no statistically significant difference in means of AI between groups 1 and 2 (P = .695) and between groups 2 and 3, with respect to AI (P = .071) and CSA (P = .125). Receiver operating characteristic curve revealed a higher area for CSA (0.70) than for AI (0.61). Stepwise logistic regression rejected AI as a cuff tear predictor but confirmed CSA and a spur to be stronger predictors of a full-thickness cuff tear. There was no association between the Bigliani acromial type and rotator cuff tear (P = .06).

CONCLUSIONS

The presence of an acromion spur is strongly associated with full-thickness cuff tear. Higher AI and CSA are associated with a full-thickness tear but not with partial tears. The type of acromion is not related to cuff tear.

Acromial approach for treating glenoid fractures: A report of two cases and a literature review

Surgery is usually recommended for displaced glenoid fractures, with open reduction and internal fixation as the standard operative treatment. Three approaches have been recommended in the reduction of glenoid fractures: Anterior, posterior and combined; however, a traditional approach may be difficult due to a high position or a comminuted Ideberg type III fracture. The combined approach results in a longer incision and more soft tissue injury when associated with an acromial fracture. The present study describes two complicated glenoid fractures: One case was a comminuted Ideberg type III fracture associated with an Ogawa type II acromial fracture; the second case was an Ideberg type IV fracture with associated superior shoulder suspensory complex injuries. In these cases, the acromial approach was modified to achieve satisfactory exposure and fixation of the complicated fracture. After a 1-year follow-up, the patients had a satisfactory outcome.

Development of secondary ossification centres of the acromion in Japanese youth: a computed tomographic study

PURPOSE

To determine the age range when the secondary ossification centres of the acromion appear and fuse in Japanese youth using computed tomography (CT).

METHODS

CT scans of 85 shoulders in 35 male and 14 female consecutive patients aged 6 to 20 (mean, 16) years were reviewed. No patient had pain or tenderness at the acromion. Appearance and fusion of the secondary ossification centres of the acromion were determined twice by an orthopaedist. A secondary ossification centre was considered to have appeared when a low-density line was noted at the juxta-epiphyseal area and to have fused when the line had disappeared. Intra-observer reliability was determined.

RESULTS

The intra-observer reliability was 0.93. The secondary ossification centres of the acromion had appeared at around 10 years of age and had fused at around 15 years of age, with one exception.

CONCLUSION

In these Japanese subjects, the secondary ossification centres of the acromion had appeared at around 10 years of age and had fused at 15 to 16 years.

Three-dimensional analysis of acromial morphologic characteristics in patients with and without rotator cuff tears using a reconstructed computed tomography model

BACKGROUND

The relationship between rotator cuff tears and acromial shape has yet to be clarified. As a result, the most suitable location for acromioplasty for the treatment of rotator cuff tears is not known.

PURPOSE

To determine whether any particular change in acromial shape is significantly associated with the presence of rotator cuff tears.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

From 2007 to 2010, we examined 25 consecutive patients with unilateral full-thickness rotator cuff tears who underwent arthroscopic repair and 17 consecutive patients with adhesive capsulitis but intact rotator cuffs who underwent arthroscopic capsular release. Before surgery, a reconstructed 3-dimensional computed tomography model was used to evaluate the acromial structure. Changes in the shape of the affected scapula were qualitatively evaluated relative to the unaffected, contralateral scapula by use of proximity mapping. Differences in acromial structure between affected and unaffected shoulders were assessed at the anterior, lateral, and medial edges and the inferior surface. The association between rotator cuff tear size and change in acromial structure was also evaluated.

RESULTS

Rates of bony projection at the anterior (>2 mm) and lateral (>3 mm) edges of the acromion in patients with rotator cuff tears were significantly greater compared with rates in patients without rotator cuff tears (P < .01). Tear size was not correlated with changes in acromial structure (P = .37-.73).

CONCLUSION

Bone spurs at the anterior and lateral edges of the acromion are associated with the presence of full-thickness rotator cuff tears in symptomatic patients.

Reliability of the posterolateral corner of the acromion as a landmark for the posterior arthroscopic portal of the shoulder

HYPOTHESIS

The present study aimed to evaluate the variability of the posterolateral corner of the acromion (PCA) position in relation to the glenohumeral joint, in a craniocaudal direction, to assess whether the universal use of a certain distance from that point will always lead to a consistent placement of the posterior arthroscopic portal of the shoulder.

METHODS

The study used 140 dried scapulae (36 women and 34 men). Measurements included the glenoid height and the perpendicular distance between the PCA and the most superior point of the glenoid. The percentage of coverage of the glenoid by the acromion was defined as the ratio between the 2 measurements. The Student t test was used to examine for significant differences between the sexes and the Student paired t test between sides (P < .05).

RESULTS

The average glenoid height was 3.37 ± 0.29 cm (range, 2.69-4.00 cm). The perpendicular distance between the PCA and the most superior point of the glenoid was 0.82 ± 0.69 cm (range, -0.35 to 2.27 cm). The percentage of coverage of the glenoid by the acromion was 24% ± 20% (range, -10% to 64%).

CONCLUSIONS

The position of the PCA in relation to the glenohumeral joint is quite variable. Therefore, the use of a universal distance from the PCA will not always lead to a consistent placement of the posterior arthroscopic portal of the shoulder. Future research is needed in this area to develop techniques to individualize placement of the posterior portal.

Arthroscopic Repair of Full-Thickness Rotator Cuff Tears With and Without Acromioplasty: Randomized Prospective Trial With 2-Year Follow-up

BACKGROUND

Acromioplasty is commonly performed during arthroscopic rotator cuff repair, but its effect on short-term outcomes is debated.

PURPOSE

To report the short-term clinical outcomes of patients undergoing arthroscopic repair of full-thickness rotator cuff tears with and without acromioplasty.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Patients undergoing arthroscopic repair of full-thickness rotator cuff tears were randomized into acromioplasty or nonacromioplasty groups. The Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) score, Constant score, University of California-Los Angeles (UCLA) score, and Short Form-12 (SF-12) health assessment were collected along with physical examination including range of motion and dynamometer strength testing. Intraoperative data including tear size, repair configuration, and concomitant procedures were recorded. Follow-up examination was performed at regular intervals up to 2 years. Preoperative imaging was reviewed to classify the acromial morphologic type, acromial angle, and lateral acromial angulation.

RESULTS

A total of 114 patients were initially enrolled in the study, and 95 (83%; 43 nonacromioplasty, 52 acromioplasty) were available for a minimum 2-year follow-up. There were no significant differences in baseline characteristics, including number of tendons torn, repair configuration, concomitant procedures, and acromion type and angles. Within groups, there was a significant (P < .001) improvement in all functional outcome scores from preoperatively to all follow-up time points, including 2 years, for the nonacromioplasty and acromioplasty groups (ASES score: 55.1-91.5, 48.8-89.0; Constant score: 48.3-75.0, 51.9-78.7, respectively). There were no significant differences in functional outcomes between nonacromioplasty and acromioplasty groups or between subjects with different acromial features at any time point.

CONCLUSION

The results of this study demonstrate no difference in clinical outcomes after rotator cuff repair with or without acromioplasty at 2 years postoperatively.

Painful os Acromiale: Conservative Management in a Young Swimmer Athlete

An os acromiale (OA) arises from a fusion failure of the anterior acromial apophysis. This case report presents the successful management of a painful OA associated to rotator cuff impingement in a competitive swimmer, based on ultrasonographic diagnosis and conservative management. Rest from sport activity, oral anti-inflammatory drugs and previous attempt of treatment of shoulder pain were ineffective. After two months of conservative treatment consisting of avoidance of swimming, local anti-inflammatory, physical therapy with ice, strengthening exercises with elastic bands to strengthen the scapular stabilizing muscles, rotator cuff and lowering humeral head muscles, the patient was pain free and all specific clinical tests for impingement syndrome (Neer, Hawkins, Whipple and Yocum tests) were negative. Digital compression of the OA site was not painful, and the Jobe and Palm-up tests were negative. The athlete returned to swim continuing the rehabilitation exercises, and the successful results were maintained at one year follow up. An unstable and symptomatic OA can be easily diagnosed with ultrasound exam. Rehabilitation for rotator cuff tendinopathies or/and bursitis can be a valid alternative to surgery. Key pointsAn os acromiale (OA) arises from a fusion failure of the anterior acromial apophysis.A correct diagnosis of OA associated to rotator cuff impingement can be performed by ultrasonographic exam.A conservative management of rotator cuff impingement syndrome, associated to OA, can be planned in athletic patients as a valid alternative to surgery.

Reliability of determining and measuring acromial enthesophytes

BACKGROUND

Although the reliability of determining acromial morphology has been examined, to date, there has not been an analysis of interobserver and intraobserver reliability on determining the presence and measuring the size of an acromial enthesophyte.

QUESTIONS/PURPOSES

The hypothesis of this study was that there will be poor intraobserver and interobserver reliability in the (1) determination of the presence of an acromial enthesophyte, (2) determination of the size of an acromial enthesophyte, and (3) determination of acromial morphology.

PATIENTS AND METHODS

Fifteen fellowship-trained orthopedic shoulder surgeons reviewed the radiographs of 15 patients at two different intervals. Measurement of acromial enthesophytes was performed using two techniques: (1) enthesophyte length and (2) enthesophyte-humeral distance. Acromial morphology was also determined. Interobserver and intraobserver agreement was determined using intraclass correlation and kappa statistical methods.

RESULTS

The interobserver reliability was fair to moderate and the intraobserver reliability moderate for determining the presence of an acromial enthesophyte. The measurement of the enthesophyte length showed poor interobserver and intraobserver reliability. The measurement of the enthesophyte-humeral distance showed poor interobserver reliability and moderate intraobserver reliability. The interobserver and intraobserver reliability in determining acromial morphology was found to be moderate and good, respectively.

CONCLUSIONS

There is fair to moderate reliability among fellowship-trained shoulder surgeons in determining the presence of an acromial enthesophyte. However, there is poor reliability among observers in measuring the size of the enthesophyte. This study suggests that the enthesophyte-humeral distance may be more reliable than the enthesophyte length when measuring the size of the enthesophyte.