The treatment of symptomatic os acromiale

Pediatric Shoulder Girdle

The pediatric shoulder girdle is a complex anatomical structure uniting the upper extremity and trunk. The osseous structures, their articulations, and the surrounding soft tissue support structures (muscles, tendons, and ligaments) allow for a wide range of motion at the shoulder. Growth and maturation of the components at the shoulder girdle vary, particularly the osseous structures. This characteristic renders interpretation of imaging of the pediatric shoulder girdle more challenging because normal or variant anatomy can be confused for pathology. We review the physiologic growth and maturation of the shoulder girdle with special emphasis on the development of the bones and their articulations. The role of various imaging modalities and the common osseous and soft tissue variants in the pediatric shoulder are also discussed.

Use of Distal Clavicle Autograft in the Treatment of Os Acromiale Open Reduction Internal Fixation: A Surgical Case Report

CASE

We present a case of a 21-year-old male patient with a symptomatic os acromiale treated with open reduction internal fixation with distal clavicle autograft. The patient presented with right shoulder pain after a motor vehicle accident with tenderness over the acromion. Radiographs demonstrated an os meso-acromion with corresponding edema on Magnetic Resonance Imaging (MRI). The patient recovered uneventfully with radiographic fusion at 8 months of the os acromiale site.

CONCLUSION

This case used the excised distal clavicle as autograft. This technique has the added advantage of harvesting autograft from the same surgical approach and potential mechanical advantage of offloading the os acromiale site to promote healing.

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 "Wallow" Procedure for Resection of Symptomatic Os Acromiale Pseudoarthrosis

Os acromiale is a relatively common anatomic variant that can occasionally be associated with shoulder pain. Several surgical options to address a symptomatic os acromiale that has failed nonoperative treatment have been described. Published techniques, however, are often very invasive, technically challenging, and carry the risk of potential complications that can be difficult to manage. The technique presented here describes a relatively simple arthroscopic alternative, coined by the authors as the "Wallow technique" due to the fact that the arthroscopic shaver is used to rotate within and resect the os site, that results in complete resection of the os acromiale pseudoarthrosis and avoids the need for an open approach or the use of implants.

Contemporary imaging of the pediatric shoulder: pearls and pitfalls

In skeletally immature patients, the presence of growth plates and articular cartilage of the shoulder can create a predisposition for unique injuries not observed in adults. Furthermore, increasing participation in sports by children and adolescents appears to be leading to a corresponding increase in the number of sports-related injuries. The importance of radiologists being familiar with pediatric shoulder imaging and its associated injuries is therefore growing. In this article, we review the normal development and maturation pattern of ossification centers of the shoulder from the early gestational period through adolescence. Brachial plexus birth palsy, physeal injuries, shoulder dislocation, and internal impingement are discussed within the context of the child's age and the mechanism of injury to guide radiologists to a correct diagnosis.

Tension Band Wiring in Upper Extremity Surgery

Tension band wiring is a simple, inexpensive, and effective technique to treat many upper extremity fractures. When tension forces result in a mechanical failure of bone, tension band wiring provides stability and promotes early mobilization by converting tensile forces across a fracture into compressive forces. The tension band principle has distinct advantages of reducing periosteal stripping, technical ease, and cost effectiveness when compared with other operative strategies. This technique can be implemented in a variety of fractures and avulsions about the upper extremity as well as small bone arthrodeses.

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.

Fixation of os acromiale using polyester sutures: a novel surgical treatment

Background

Patients with unstable os acromiale often complain of shoulder pain. Numerous surgical treatment options have been introduced with inconsistent clinical results. In this study, a novel surgical treatment using polyester sutures to fix unstable os acromiale was introduced, and clinical results were reported.

Methods

We retrospectively studied 10 shoulders that were diagnosed with os acromiale from January 2014 to January 2016. All 10 cases were of the meso-acromion type. Except for the first case in our series, cases of os acromiale were fixed using polyester sutures arthroscopically. The standardized scores and visual analog scale (VAS) were recorded preoperatively and at each follow-up. A computed tomography (CT) scan was ordered at the follow-up of 12 months.

Results

The average follow-up length was 28.7 months, ranging from 26 to 33 months. The average Constant score before surgery was 40.50±4.53 points, which significantly improved to 75.60±5.17 points after surgery. The average VAS score was reduced from 5.20±1.14 points to 1.60±0.84. At the follow-up of 12 months, a CT scan was ordered. All the patients showed a bony union of the os acromiale. On the CT scan, two small pits could be seen on the medial and lateral side of the acromion, which indicated the level of the os acromiale. The position of the os acromiale was good, and no evident sclerosis was found on the edges of the fragments.

Conclusions

Polyester sutures could provide reliable strength for the fixation of os acromiale without any irritation from hardware.

Os Acromiale: Reviews and Current Perspectives

Os acromiale is a developmental defect which results from the lack of an osseous union between the ossification centers of the acromion, leading to the fibrocartilaginous tissue connection. The prevalence of os acromiale is 1% to 15%, and is quite common in the African American population. Os acromiale in adults is easily diagnosed by symptoms and X-ray, particularly on the axillary view; however, the differential diagnosis of adolescents may require MRI or SPECT-CT. Generally, nonoperative therapy for symptomatic os acromiale should be started, including physiotherapy, nonsteroidal anti-inflammatory drugs, and injections. Surgical treatment is indicated after failed conservative treatment. In symptomatic patients with fixable acromiale, the tension band technique should be used to make the anterior aspect of the acromion elevated from the humerus head. In patients with small fragments which are unsuitable for reattachment, excision might be the best therapeutic option and lead to good outcomes. Whether using internal fixation or resection, the arthroscopic technique results in a better outcome and fewer complications, especially in older patients or athletes with overhead movement, because of the high incidence of shoulder impingement or rotator cuff tears which can be treated concurrently.

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

The traumatic acromion fracture: review of the literature, clinical examples and proposal of a treatment algorithm

PURPOSE

Traumatic acromion fractures are rare and typically occur in patients with multiple fractures, which often delays diagnosis. Limited guidance exists on the treatment of these fractures. We present a review of the literature from the last 20 years and describe our experience in treating five patients-two conservatively and three with open reduction and internal fixations (ORIF).

METHODS

We used the U.S. National Library of Science database, MEDLINE^®, to search for all pertinent publications from January 1999 to December 2017. Included were retrospective or prospective studies, including case series and case reports, describing treatment for traumatic acromion fractures and clinical and/or radiological outcomes. For our case reports, we present five patients with traumatic acromion fractures who were treated at our institution between 2013 and 2017.

RESULTS

Through our review of 14 publications, we found that current recommendations are often based on a limited number of cases. No gold standard to treat these fractures exists. Most authors recommend anatomic reconstruction, especially for dislocated fractures, persistent symptomatic non-unions or additional injuries to the superior shoulder suspensory complex. There is no clear trend in terms of the operative technique. With regard to our five clinical examples that were all initially treated conservatively, two were successful and three eventually required reconstruction with ORIF. Based on the findings of this review, we proposed a treatment algorithm for traumatic acromion fractures.

CONCLUSIONS

A classification system providing clear guidance on treatment options is needed. Although the non-union rate with conservative treatment is relatively high, it is not always painful or limiting to shoulder function, especially in elderly or less active patients. Fixation seems to be a more suitable treatment option for active patients who are more likely to require revision of symptomatic non-unions.

Clinical results and complications following surgical management of symptomatic os acromiale: a systematic review

Background

This review compares the outcomes and complication rates of three surgical strategies used for the management of symptomatic os acromiale. The purpose of this study was to help guide best practice recommendations.

Methods

A systematic review of nine prospective studies, seven retrospective studies, and three case studies published across ten countries between 1993 and 2018 was performed. Adult patients (i.e., ≥ 18 years of age) with a symptomatic os acromiale that failed nonoperative management were included in this review. Surgical techniques utilized within the included studies include excision, acromioplasty, and open reduction and internal fixation (ORIF). The primary outcomes of interest included patient satisfaction. Range of motion and several standardized outcome measurement tools were also included in the final analysis.

Results

Patient satisfaction was highest in the excision and ORIF groups, with 92% and 82% of patients reporting good to excellent postoperative results, respectively, compared to 63% in the acromioplasty group. All three patient groups experienced improvements in postoperative outcomes (i.e., active range of motion and patient-reported outcome scores). The excision group experienced a complication rate of 1%, while the acromioplasty group experienced a complication rate of 11% and the ORIF group a rate of 67%.

Conclusion

This study reports on the largest sample of patients who underwent surgical treatment for a symptomatic os acromiale. We have demonstrated that excision of the os with meticulous repair of the deltoid resulted in the best clinical outcomes with the least complications. In healthy adult patients with a large os fragment and a normal rotator cuff, surgical fixation may provide increased preservation of deltoid function while offering good to excellent patient satisfaction. However, patients must be informed that a second procedure may be required to remove symptomatic hardware.

Management of symptomatic os acromiale: a survey of the American shoulder and elbow surgeons

BACKGROUND

The purpose of this paper was to survey members of the American Shoulder and Elbow Surgeons (ASES) to assess their opinion on management options, help highlight important clinical factors, and elucidate surgical preferences for the treatment of a symptomatic meso-os.

METHODS

An online questionnaire was distributed to the active members of the ASES. The survey queried surgeon demographics and perioperative management preferences, and presented multiple clinical case scenarios of patients with a presumed symptomatic, unstable os acromiale.

RESULTS

There were 116 ASES members who responded to the survey, and 26% (n = 30) who stated they do not operatively manage a symptomatic os. We identified two main clusters of respondents. Cluster 1 (n = 67) (as compared to cluster 2, n = 19) was comprised of surgeons with significantly more experience treating a symptomatic os acromiale (p < 0.05). These surgeons regarded gender, age, BMI, and hand dominance as important clinical factors when deciding when to proceed to surgery. Overall, arthroscopic management of the os was preferred, but those surgeons more experienced in treating os acromiale preferred open reduction and internal fixation (ORIF) in specific clinical cases.

CONCLUSION

The survey findings reflect the current lack of consensus in the treatment of a unstable, symptomatic os acromiale. Overall, arthroscopic management was preferred by most surgeons, though ORIF was preferred in certain clinical scenarios by those more experienced with os acromiale. The overall preference for arthroscopy suggests a possible shift in the treatment paradigm for patients with symptomatic meso-acromions, but higher level studies are needed to substantiate these findings.

Symptomatic, Unstable Os Acromiale

Management of a persistently symptomatic, unstable os acromiale remains controversial. An unstable os acromiale is an easy diagnosis to miss and should be specifically evaluated for in patients with shoulder pain and a high degree of clinical suspicion. Surgical options include open or arthroscopic excision and open reduction and internal fixation. Open excision of large fragments has had poor results. Arthroscopic treatment is commonly used for small fragments (preacromion), and the technique has also been used in larger fragments (meso-os), but concerns persist over postoperative weakness secondary to shortening of the deltoid lever arm. Open reduction and internal fixation through a transacromial approach has been shown to have predictable union rates but can be complicated by symptomatic implant. Recent biomechanical studies have expanded our understanding of optimal fixation constructs, which may also decrease implant-related issues. Ultimately, the choice of which procedure to use will be dictated by patient factors such as age, activity level, and the nature of rotator cuff pathology. LEVEL OF EVIDENCE:: Level V.

Small but troublesome: accessory ossicles with clinical significance

Accessory ossicles are supernumerary and inconstant structures that are not caused by fractures. Derived from unfused ossification centers, accessory ossicles were first described by Vesalius in 1543. For centuries, they were believed to be asymptomatic. However, with advances in radiology techniques, many have been associated with painful syndromes. Although the original descriptions date from the sixteenth century, the subject is little discussed and, in some cases, controversial. The objective of this study was to describe the radiological aspects of a series of accessory ossicles and to review the evolution of their various descriptions, in order to revive discussion of the subject.

Os Acromiale in Professional Tennis Players

Background:

Os acromiale is a rare condition mostly reported in the literature through case reports, imaging studies, or reports of surgical treatment. This condition is the result of nonunion of growth plates of the acromion during the natural developmental process that occurs between 15 and 25 years of age. Its incidence is low, and few studies are available in the literature on athletes with high functional demands, and particularly on athletes within a specific sport.

Purpose:

To collect epidemiological data and to report the amount of time out of play as well as the type of treatment and its efficiency in professional tennis players.

Study Design:

Case series; Level of evidence, 4.

Methods:

We performed a retrospective study using the medical data of athletes within our national tennis league who complained about their shoulder between 2011 and 2016. Nine professional tennis players (mean age, 20 years) with painful shoulders were diagnosed with os acromiale; 3 of them played at an international level, with the other 6 playing at a national level. The diagnosis was confirmed using radiography, including the axillary view, and magnetic resonance imaging (MRI). One female player had associated subacromial bursitis.

Results:

All cases of os acromiale were classified as involving the mesoacromion, following the Lieberson classification. No patient underwent surgery, and no patient was treated with local or subacromial infiltration. Patients stopped competition and training throughout the rehabilitation period. All patients received medical treatment with nonsteroidal anti-inflammatory drugs (NSAIDs), ice, and physical therapy with a specific rehabilitation program. All athletes returned to their former level of play after a mean of 37 days. No patient suffered from recurrent pain. One patient underwent MRI after 2 years, showing a normal bone signal and complete healing of the acromion.

Conclusion:

Conservative treatment including NSAIDs, rest, ice, and physical therapy allowed for good recovery and return to the former level of play. Surgical treatment is usually not indicated for os acromiale in the professional tennis player.

Os acromiale open reduction and internal fixation: a review of iliac crest autogenous bone grafting and local bone grafting

BACKGROUND

Symptomatic os acromiale are fairly uncommon, and treatment has included fragment excision, decompression, and open reduction and internal fixation. Nonunion rates as high as 40% have been reported after fixation of os acromiale. This study assessed whether union of an os acromiale could be reliably achieved without the use of an iliac crest bone graft.

METHODS

This was a retrospective study of 32 consecutive shoulders that were treated with screw fixation and a local bone graft or iliac crest bone graft. The mean age was 50.3 years (range, 21-74 years), and the mean follow-up was 46.9 months (range, 12-120 months). Fusion was assessed clinically and radiologically.

RESULTS

All 32 os acromiale were fused by 3 months on x-ray imaging. There were 18 shoulders in the iliac crest bone graft group and 14 in the local bone graft group. Rotator cuff repairs were performed concomitantly in 25 patients. Hardware was removed in 4 patients, a seroma was drained in 1 patient, and a superficial infection occurred in 1 patient.

CONCLUSION

This is the largest study of os acromiale fixation using screws and a tension band to our knowledge. We report a 100% union rate using this technique, with 13% requiring hardware removal and the occurrence of 1 superficial infection. This study shows a local bone graft is as effective as iliac crest bone graft in achieving fusion.

Optimal management of symptomatic os acromiale: current perspectives

The majority of os acromiale is asymptomatic and requires no treatment. In patients with shoulder pain, os acromiale is a possibility in the differential diagnosis and may imitate shoulder impingement. The diagnosis of symptomatic os acromiale can be proven by combining physical examination, conventional radiographs, magnetic resonance imaging, and selective injections. Surgical treatment is indicated in those patients with failed conservative therapy, in those with highly painful and unstable os acromiale, or in those with associated shoulder pathologies such as rotator cuff tears. Open or arthroscopic excision is indicated in patients with pre-type os acromiale. In meso-type acromiale, arthroscopic excision, acromioplasty, or open reduction and internal fixation have all been used, but fixation is usually preferred. Internal fixation should be done either with cannulated screws alone or in combination with tension band, which has biomechanical advantages.

Initial experience with 18F-sodium fluoride (NaF) PET-CT: a viable functional biomarker in symptomatic Os acromiale

OBJECTIVE

Os acromiale (OA) is a failure of complete fusion of the acromial process. It is usually asymptomatic and discovered incidentally. OA can contribute to shoulder impingement symptoms and rotator cuff tears. ¹⁸F Sodium Fluoride (NaF) Positron Emission Tomography -CT (PET-CT) is an emerging and highly sensitive modality for oncological skeletal staging, and can show a variety of non-malignant uptake. We have analysed the relationship between ¹⁸F-NaF uptake in OA and associated symptoms of shoulder pain.

METHODS

Study population included 21 patients (mean age 60.2 ± 12 years; 13 females and 8 males) with OA who underwent PET-CT scan by injecting 2.22 MBq kg^-1 of ¹⁸F-NaF. The relationship between ¹⁸F-NaF uptake and OA as a cause of pain was analysed. A 3-point grading system was used to evaluate uptake of ¹⁸F-NaF.

RESULTS

In total 27 OA (12 symptomatic and 15 asymptomatic) were enrolled. All symptomatic OA showed focal increase tracer uptake of Grade 2, while asymptomatic OA did not have significant activity Grade 0 (n = 11) and Grade 1 (n = 4).

CONCLUSION

¹⁸F-NaF PET-CT appears to be a useful adjunct in the assessment of symptomatic OA with its particular strength being its high negative predictive value. Advances in knowledge: ¹⁸F-NaF PET-CT may be used as an ancillary tool for identifying symptomatic OA  as a cause of shoulder pain in cases where other obvious causes of shoulder pain have been excluded.

Reverse shoulder arthroplasty in patients with os acromiale

BACKGROUND

Os acromiale has been reported in up to 15% of the general population. Reverse total shoulder arthroplasty (RTSA) increases deltoid tension, which could potentially lead to excessive stress on a pre-existent os acromiale. The purpose of this study was to determine the outcome and complications of primary RTSA in patients with radiographic evidence of an os acromiale.

METHODS

Between 2005 and 2013, 25 shoulders underwent primary RTSA with an associated os acromiale, which was classified preacromion (3), mesoacromion (20), and meta-acromion (2). All patients were observed for a minimum of 2 years or until reoperation. Mean follow-up time was 30.8 (range, 1-81.4) months. Outcomes included pain scores, range of motion, patient satisfaction, American Shoulder and Elbow Surgeons scores, and radiographic outcomes.

RESULTS

RTSA led to an improvement in pain scores in 24 of 25 shoulders. Mean elevation, external rotation, and internal rotation were improved at final follow-up (124°, 46°, and L4, respectively). Three patients required reoperation, including revision surgery for dislocation (2) and excision of a painful os acromiale (1). Postoperative tilting of the os acromiale was noted in 7 shoulders (28%). There was no statistically significant difference in any outcome measures between shoulders with and shoulders without postoperative tilt of the os acromiale.

DISCUSSION AND CONCLUSION

The outcome of RTSA does not seem to be negatively affected by the presence of an os acromiale. Pain around an os acromiale after RTSA is rare. Inferior tilting is observed in approximately one-third of the shoulders after RTSA and does not seem to change the overall outcome.

Operative Treatment of Symptomatic Meso-Type Os Acromiale

Os acromiale occur frequently in the population and can be a cause of significant shoulder dysfunction and rotator cuff impingement. When symptomatic os acromiale fail conservative management, surgical intervention may become necessary. The purpose of this article is to describe our preferred surgical technique for osteosynthesis of os acromiale using cannulated screws and tension-band wiring.

Os acromiale: frequency and a review of 726 shoulder MRI

Os acromiale consist in a lack of fusion between the different ossification spots of the acromial side of scapula from the age of 23-25 years. A relation between os acromiale and some shoulder pathology like impingement syndrome, cuff tear and subacromial bursitis has been described. The etiology is not already known. The aim of this study was to evaluate the frequency of os acromiale in our population, the link between os acromiale and sex, side and shoulder pathology. 1042 shoulder MRI were evaluated to find out os acromiale and the linked cuff pathology. In our population, the frequency of os acromiale was 3.44% without differences between sexes, with prevalence on the right shoulder. No differences in cuff and bursa pathology were present between affected and unaffected subjects. Os acromiale is an anomaly still underdiagnosed. It is important to be recognized because it allows to make an accurate pre-surgical plan. To make a correct diagnosis, axial MRI cut or TC is necessary.

Arthroscopic Excision of a Symptomatic Meso-acromiale

The surgical technique for the management of a symptomatic os acromiale remains unclear. Several operative techniques have been described including open excision, open reduction-internal fixation (ORIF), arthroscopic acromioplasty or subacromial decompression, and arthroscopic excision. There are 4 types of os acromiale, with the meso-acromion being the most common and difficult to treat. The excision of a pre-acromion arthroscopically or in an open manner usually produces satisfactory results. However, the open excision of a meso-acromion can lead to persistent pain and deltoid weakness and atrophy. The management of a meso-acromial fragment with ORIF can also result in persistent pain and deltoid weakness and atrophy with nonunion of the fragments. The purpose of this article is to describe an alternative surgical technique to open excision or ORIF when presented with a symptomatic meso-acromiale.

Arthroscopic excision of unstable os acromiale associated with impingement syndrome: a case report

Os acromiale is a rare anatomical variant that is caused by failure of fusion of the acromial apophysis and is usually asymptomatic. We report a case of impingement syndrome of the left shoulder secondary to unstable os acromiale, which was initially overlooked and confirmed only during arthroscopic examination. Arthroscopic excision of the unstable fragment was successful without residual dysfunction of the deltoid muscle.

Os acromiale fixation: a biomechanical comparison of polyethylene suture versus stainless steel wire tension band

BACKGROUND

Symptomatic hardware is a commonly reported complication after surgical fixation of an unstable meso-type os acromiale. This study compared the biomechanical properties of a cannulated screw tension band construct using a metal wire tension band vs. a suture tension band, considering that the suture construct could allow for decreased hardware burden in the clinical setting.

METHODS

A meso-type os acromiale was created in 16 cadaveric shoulders. Two cannulated 4-mm screws were placed in each specimen. Tension band augmentation was accomplished with a 1-mm stainless steel wire (wire group) or a #5 braided polyethylene suture (suture group), with 8 specimens in each group. An inferiorly directed force was applied to the anterior acromion at 1 mm/s on a materials testing machine. Stiffness and ultimate failure load were recorded and analyzed.

RESULTS

No significant difference (P = .22) was observed in the ultimate failure load between the wire (228  ± 85 N; range, 114-397 N) and the suture (275 ± 139 N; range, 112-530 N). No significant difference (P = .17) was observed in the stiffness between the wire (28  ± 12 N/mm; range, 18-53 N/mm) and the suture (38  ± 25 N/mm; range, 10-83 N/mm).

CONCLUSIONS

Stainless steel wire and polyethylene suture have similar biomechanical strength in the cannulated screw tension band fixation of meso-type os acromiale at time zero.

[Arthroscopic subacromial decompression]

OBJECTIVE

Coracoacromial ligament release to widen the subacromial space, resection of the anterior undersurface of the acromion and, if needed, caudal exophytes at the acromioclavicular joint.

INDICATIONS

All types of outlet impingement after 3 months of conservative treatment.

CONTRAINDICATIONS

Impingement syndrome with instability/muscular imbalance, massive rotator cuff tear, unstable os acromionale, posterior-superior impingement, joint infection, freezing phase of a secondary frozen shoulder.

SURGICAL TECHNIQUE

Lateral decubitus position with traction device for the arm. Diagnostic arthroscopy of the glenohumeral joint via standard portals. With arthroscope moved to the subacromial space, bursectomy, electrosurgical release of coracoacromial ligament, resection of acromial hook through standard posterior portal.

POSTOPERATIVE MANAGEMENT

Physiotherapy or self-exercises on postoperative day 1, pain-adapted analgesia to avoid shoulder stiffness.

RESULTS

Several studies present positive long-term results compared to conservative treatment (and open acromioplasty) for partial rotator cuff tears and for elderly patients. With a 20-year follow-up, successful results have been achieved for all patients with isolated impingement syndrome.

Differentiating os acromiale from normally developing acromial ossification centers using magnetic resonance imaging

OBJECTIVE

Acromial fusion may not be complete until age 18-25, making it questionable to diagnose os acromiale in adolescents. Os acromiale may exist in adolescents and can be differentiated from a developing acromial ossification center based on MRI findings.

MATERIALS AND METHODS

A total of 128 MRIs of the shoulder were randomly and blindly reviewed retrospectively by two musculoskeletal radiologists. The MRIs consisted of two groups: (1) 56 of os acromiale in adults (25-74 years old, mean, 50) and (2) 72 consecutive of adolescents (12-17 years old, mean, 14.5). The following were assessed at the interface between the distal acromion and os acromiale/developing ossification center(s): presence of os acromiale vs. developing acromion, orientation, margins, and edema within and adjacent to it.

RESULTS

Fifty-one adults and 49 adolescents were included. Exclusions were due to poor image quality or confounding findings (n = 7) or complete acromial fusion (n = 21 adolescents). Utilizing accepted definitions of os acromiale, all adult cases (100 %) were accurately diagnosed as os acromiale, with transverse interface orientation and irregular margins (94 %, R = 0.86, p < 0.00001). Forty-five (92 %) adolescent cases were accurately diagnosed as normally developing acromion with arched interface and lobulated margins (92 %, R = 0.92, p < 0.000001). Four (8 %) adolescent cases were diagnosed as having os acromiale, with transverse orientation and irregular margins. Thirty-five (69 %) and 46 (90 %) adults had marrow and interface edema, respectively. Six (12 %) and eight (16 %) adolescents had marrow and interface edema, respectively, including the four concluded to be os acromiale.

CONCLUSIONS

Adolescents may have imaging findings consistent with os acromiale. The diagnosis of os acromiale should be based on imaging features and not limited by age.

Biomechanical evaluation of internal fixation techniques for unstable meso-type os acromiale

BACKGROUND

Several internal fixation surgical techniques have been described for the treatment of symptomatic os acromiale. The purpose of this study was to compare the biomechanical characteristics of different internal fixation techniques for the operative treatment of unstable meso-type os acromiale in a cadaveric model.

METHODS

Testing was performed on 12 matched pairs of cadaveric acromia with simulated meso-type os acromiale. Twelve specimens were prepared with 2 cannulated 4.0-mm screws only (SO group), inserted in the anterior-posterior direction. Contralateral specimens were repaired with screws and a tension band (TB group). An inferiorly directed load to the anterior acromion was applied at a rate of 60 mm/min until failure. Ultimate failure load, stiffness, and fracture pattern were recorded and analyzed.

RESULTS

Ultimate failure load was significantly higher for the TB group (mean, 336 N ± 126 N; range, 166-623 N; P = .01) than for the SO group (mean, 242 N ± 57 N; range, 186-365 N). In contrast, no significant difference in stiffness was found between the SO group (mean, 22.1 N/mm ± 4.7 N/mm; range, 13.0-33.3 N/mm; P = .94)) and the TB group (mean, 22.2 N/mm ± 2.9 N/mm; range, 18.2-26.6 N/mm).

CONCLUSION

Surgical repair of simulated unstable meso-type os acromiale by a combination of cannulated screws with a tension band leads to significantly higher repair strength at time zero in a cadaveric model compared with cannulated screws alone.

Rotator cuff tear: A detailed update

Rotator cuff tear has been a known entity for orthopaedic surgeons for more than two hundred years. Although the exact pathogenesis is controversial, a combination of intrinsic factors proposed by Codman and extrinsic factors theorized by Neer is likely responsible for most rotator cuff tears. Magnetic resonance imaging remains the gold standard for the diagnosis of rotator cuff tears, but the emergence of ultrasound has revolutionized the diagnostic capability. Even though mini-open rotator cuff repair is still commonly performed, and results are comparable to arthroscopic repair, all-arthroscopic repair of rotator cuff tear is now fast becoming a standard care for rotator cuff repair. Appropriate knowledge of pathology and healing pattern of cuff, strong and biological repair techniques, better suture anchors, and gradual rehabilitation of postcuff repair have led to good to excellent outcome after repair. As the healing of degenerative cuff tear remains unpredictable, the role of biological agents such as platelet-rich plasma and stem cells for postcuff repair augmentation is still under evaluation. The role of scaffolds in massive cuff tear is also being probed.

The prevalence of Os acromiale: a systematic review and meta-analysis

Os acromiale (OA) results from a failure of consolidation between the ossification centers of the acromial epiphysis. Its prevalence and its interactions with ancestry, gender, laterality, and side have been variously reported in the literature. The aims of this review are to provide an accurate estimate of OA prevalence and to investigate its association with other variables in an attempt to comprehend its etiology. Twenty-three studies met the inclusion criteria. The results of meta-analyses of large-sample studies revealed: (a) a crude overall prevalence of 7.0%, (b) a crude cadaveric prevalence of 7.6%, (c) a crude archeological (skeletal) prevalence of 5.6%, (d) a crude radiological prevalence of 4.2%, (e) a true anatomical prevalence of 9.6%, (f) a significantly higher frequency in persons of black ancestry than in persons of white, Native American and Middle Eastern ancestries (OR ≈ 3), (g) significantly higher unilateral and bilateral frequencies in black ancestry (OR of 2 and 4, respectively), (h) nonsignificant interactions of OA frequency with gender and side. The commonest type of OA was the meso-acromion type (76.6%). Degenerative changes were present in 66.6% of OAs. The results of this evidence-based anatomical review support a genetic basis for OA rather than the mechanical trauma-induction hypothesis.

Degenerative joint disease of the acromioclavicular joint: a review

Osteoarthritis of the acromioclavicular (AC) joint is a common condition causing anterior or superior shoulder pain, especially with overhead and cross-body activities. This most commonly occurs in middle-aged individuals because of degeneration to the fibrocartilaginous disk that cushions the articulations. Diagnosis relies on history, physical examination, imaging, and diagnostic local anesthetic injection. Diagnosis can be challenging given the lack of specificity with positive physical examination findings and the variable nature of AC joint pain. Of note, symptomatic AC osteoarthritis must be differentiated from instability and subtle instability, which may have similar symptoms. Although plain radiographs can reveal degeneration, diagnosis cannot be based on this alone because similar radiographic findings can be seen in asymptomatic individuals. Nonoperative therapy can provide symptomatic relief, whereas patients with persistent symptoms can be considered for resection arthroplasty by open or arthroscopic technique. Both techniques have proven to provide predictable pain relief; however, each has its own unique set of potential complications that may be minimized with an improved understanding of the anatomical and biomechanical characteristics of the joint along with meticulous surgical technique.

Os acromiale: a review and an introduction of a new surgical technique for management

Os acromiale is a common finding in shoulder surgery. We review the anatomy, prevalence, pathophysiology, and treatment options for this diagnosis. In addition, we report on a case series of 6 patients with a symptomatic meso os acromiale who were treated with a new technique involving arthroscopic acromioplasty in conjunction with the excision of the acromial nonunion site. We have demonstrated this novel treatment method to be a safe and effective technique in this case series. This arthroscopic partial resection of an os acromiale is considered to be an alternative option for treating a symptomatic meso os acromiale.

The prevalence of os acromiale in Korean patients visiting shoulder clinic

Background

The prevalence of os acromiale has been documented to be between 1% and 15% and is known to be clinically associated with subacromial impingement or rotator cuff tear. However, the prevalence of os acromiale in Korea has not yet been determined. The purpose of this study is to evaluate the prevalence of os acromiale in Korean patients who visited shoulder clinics and to investigate the correlations with rotator cuff tear.

Methods

We retrospectively reviewed the X-rays of patients visiting a shoulder clinic at a tertiary hospital in Korea from January 2011 to January 2012 to determine the frequency of os acromiale. X-ray findings were confirmed with magnetic resonance imaging (MRI) for patients who had these images available. MRI was also used to assess the status of the rotator cuff. The correlation between the presence of os acromiale either with gender, hand dominance or rotator cuff tear was analyzed statistically.

Results

A total of 2,946 shoulders from 1,568 patients were analyzed with X-rays. Thirteen cases out of 1,568 patients had an os acromiale; and there were five and eight cases of pre-acromiale and meso-acromiale, respectively. Thus, the prevalence of os acromiale in this study population was found to be 0.7 (7 cases per 1,000 patients). Bilaterality was found in two cases. Os acromiale was not more frequent according to gender (five males versus eight females, p = 0.525) and hand dominance was not associated with frequency of os acromiale (seven dominant arms versus six non-dominant arms, p = 0.631). A sub-analysis of shoulders with available MRIs (1,074 shoulders) revealed that there were two rotator cuff tears (40%) out of five cases of os acromiale, whereas 607 rotator cuff tears were observed (57%) among 1069 cases without os acromiale. This difference was not statistically significant (p = 0.656).

Conclusions

The identified prevalence of os acromiale in Korean patients who visited shoulder clinics is 0.7%, which is much lower as compared with the prevalence of general population from other ethnic groups. No correlation was observed between rotator cuff tears and os acromiale in this study population.

Os acromiale, a cause of shoulder pain, not to be overlooked

INTRODUCTION

Os acromiale is a failure of fusion of the acromial process. It is usually asymptomatic and discovered by chance. When it is painful a differential diagnosis must be made in relation to the subacromial impingement syndrome.

HYPOTHESIS

Unstable os acromiale is the cause of atypical scapulalgias. Stabilization by tension band wiring and an embedded slot shaped graft achieves union and relieves pain. PATIENTS ET METHODS: This series includes 10 patients mean age 43 years old presenting with shoulder pain resistant to a mean 15 months of conservative treatment. Pain followed trauma in three cases. Three patients had a history of acromioplasty, which had not relieved pain. All had pain during palpation of the superior aspect of the acromion. The diagnosis was confirmed in eight patients by positive results to local injection of the os acromiale. The mean preoperative Constant score was 53.4. The procedure included open reduction and fixation of the acromion by tension band wiring and pinning associated with an embedded iliac crest graft without acromioplasty.

RESULTS

The mean follow-up was 48 months. Pain was relieved in seven cases and all patients had improved and were satisfied. Union of os acromiale was confirmed on CT scan in all patients. The mean Constant score was 82.2.

DISCUSSION

The role of os acromiale in the origination of pain is confirmed by the efficacy of preoperative injection of the os acromiale and pain relief after achieving union. Moreover, our technique is reliable and always resulted in union of the os acromiale. Internal fixation by tension banding favors minimal upward migration of the os acromiale and union. In case of subacromial impingement syndrome an os acromiale should be looked for, as this condition could deteriorate with simple acromioplasty.

LEVEL OF EVIDENCE

Level IV retrospective observational study.

Arthroscopically assisted internal fixation of the symptomatic unstable os acromiale with absorbable screws

BACKGROUND

Symptomatic meso- type os acromiale is a common pathology with inconsistent outcomes of treatment with various surgical techniques. We report the outcome of a new technique for arthroscopic fusion of symptomatic os acromiale with absorbable screws.

MATERIALS AND METHODS

The study included 8 shoulders in 8 patients with symptomatic meso- type os acromiale who were treated with the use of a new technique for arthroscopic fusion with absorbable screws. The mean age was 54 years (range, 38-67 years), and the mean time from onset of symptoms to surgery was 18 months (range, 9-25 months). No patients reported a specific traumatic event before the onset of symptoms, and all noted the insidious onset of pain with no precipitating event.

RESULTS

The average length of follow-up was 22 months (range, 12-36 month). The average Constant score improved from 49 points (range, 35-57 points) to 81 points (range, 75-86 points). The average satisfaction score improved from 4.5 of 10 (range, 2-6) to 8.5 of 10 (range 7-9). All patients made a good clinical recovery at 3 to 6 months after surgery. At the last follow-up, full radiographic union was observed in 6 patients, partial union in 1 patient, and persistent radiologic nonunion in 1 patient. Anterior bulging of the absorbable screws was noted in 2 patients, and the screws were trimmed 6 months after the first procedure.

CONCLUSIONS

We have found that this new arthroscopic technique of fixation of os acromiale with absorbable screws provides promising clinical, cosmetic, and radiologic results with high patient satisfaction.

Arthroscopic excision of os acromiale: effects on deltoid function and strength

Arthroscopic excision of os acromiale is a feasible alternative to open excision or fusion. This article describes the authors' experience with 28 patients (31 shoulders) who underwent arthroscopic excision of os acromiale and its effect on shoulder pain and function, with specific emphasis on deltoid strength measurement. Thirty-one os acromiale (all persistent unfused pre- and meso-acromions) in 28 patients were excised arthroscopically. Sixteen patients underwent concomitant rotator cuff repair (9 arthroscopic and 7 mini-open). At an average follow-up of 41 months, the patients were assessed using the American Shoulder and Elbow Surgeons (ASES) score, and deltoid function and strength were measured. Pain was completely alleviated postoperatively in 20 (65%) shoulders, and 9 (29%) shoulders had less pain postoperatively. Pain worsened postoperatively in 2 patients, both of whom had features of glenohumeral arthritis at arthroscopy. Average postoperative ASES score (80.33) was significantly improved compared with the average preoperative score (33.71). No significant loss of deltoid strength occurred compared with the contralateral side. No objective or subjective loss of normal deltoid appearance occurred. Rotator cuff repair did not compromise deltoid strength or significantly reduce ASES score irrespective of repair technique (arthroscopic vs mini-open). With careful attention to surgical technique maintaining an intact periosteal sleeve to preserve the integrity of the deltoid attachment, arthroscopic excision is an effective management tool for mobile os acromiale in a painful shoulder requiring surgical intervention.

Evaluation and treatment of rotator cuff tears

Rotator cuff injuries are common problems and a frequent reason for patients to present to primary care physicians. These injuries are seen more frequently now with the aging population. These muscles allow for movement of the arm in overhead activities and controlled movements through space. A thorough physical examination can lead to the diagnosis of rotator cuff pathology. Radiographic imaging may offer some insight into the underlying pathology, and magnetic resonance imaging provides for excellent visualization of the rotator cuff. Many rotator cuff tears, especially partial tears, will symptomatically improve with conservative management. Surgical treatment may offer improved pain relief and function in those patients for whom nonoperative care is insufficient. In cases in which rotator cuff repair is not possible, the reverse total shoulder arthroplasty is a possibility. New technologies are also under investigation that allow for biological augmentation of rotator cuff tears.

Magnetic resonance imaging of rotator cuff disease and external impingement

Magnetic resonance (MR) imaging plays a major role in helping to identify rotator cuff disease and in demonstrating the pathology associated with external impingement. Many surgeons rely on MR imaging to assist in decision making and presurgical planning for patients with rotator cuff pain. This article reviews the etiology of external impingement and rotator cuff tears, and describes the MR imaging appearance of the normal and the pathologic rotator cuffs. It focuses on the supraspinatus tendon because this is the tendon involved in 95% of rotator cuff tears.

Systematic review of the surgical treatment for symptomatic os acromiale

The optimal surgical treatment for symptomatic os acromiale that has failed nonoperative management is unclear in the literature. We conducted a systematic review of multiple medical databases for level I–IV evidence. Both radiographic and clinical outcomes were analyzed. Nine studies met the inclusion criteria (118 subjects, 125 shoulders). One hundred and fifteen subjects were treated surgically (122 shoulders). The mean age of the subjects was 49±11 years. The mean preoperative duration of symptoms was 12±8.6 months. Mesoacromiale was the most common type treated (94%). Internal fixation was the most common surgical technique used (60%), followed by excision (27%) and acromioplasty (13%). Rotator cuff repair was the most common concurrent surgical technique (performed in 59% of the surgically treated shoulders), followed by distal clavicle excision (25%). All surgical techniques resulted in improvement in clinical outcomes. Surgical management of symptomatic os acromiale that has failed nonoperative measures may predictably lead to improved outcomes.

[Reconstruction of an iatrogenic acromial pseudarthrosis: a case report]

Acromial fractures are rare but severe complications which can occur during subacromial decompression. We report a case of acromial pseudarthrosis which was discovered belatedly due to persistent pain after several operations. The pseudarthrosis was successfully treated by osteosynthesis with a distal radius plate and implantation of a monocortical bone graft from the iliac crest. Two years after surgery, the fracture has healed and the patient's pain improved significantly. In the constant score the patient achieved postoperatively 58 points compared to 25 points before surgery and 65 points compared to 25 points preoperatively in the subjective shoulder rating system (SSRS). Postoperatively, the patient had a better range of motion with active abduction/adduction of 50/0/25º (30/0/20° preoperatively), outward rotation/inward rotation of 35/0/45º (30/0/30° preoperatively) and anteversion/retroversion of 60/0/35° (35/0/20° preoperatively).

The diagnosis and prognosis of impingement syndrome in the shoulder with using quantitative SPECT assessment: a prospective study of 73 patients and 24 volunteers

BACKGROUND

Diagnosing impingement syndrome without rotator cuff tear usually depends on the physical examination and roentgenography, and obtaining objective evidence for this condition is at best difficult. The purpose of this study was to ascertain whether quantitatively assessing this condition with using single photon emission computerized tomography (SPECT) can diagnose impingement syndrome and predict the postoperative results.

METHODS

Before executing arthroscopic or open treatment, SPECT was performed on 73 patients and 24 volunteers and these people were followed up for 2 years. Any increased uptake on SPECT was investigated by using the axial view, which demonstrated the greatest uptake for the acromion, distal clavicle, greater tuberosity, lesser tuberosity and the coracoid process of the operated and non-operated sides.

RESULTS

The patients who were diagnosed as having impingement syndrome with or without rotator cuff tear showed increased uptake on the operative side compared to the non-operated side in the assessed locations. The greater tuberosity of the humerus could be used for quantitative measurement as a postoperative prognostic factor.

CONCLUSIONS

The bone SPECT method is useful for making the diagnosis of patients with impingement syndrome, and the results of quantitative assessment at the greater tuberosity can be used for evaluating the prognosis following the operation.