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

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.

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

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

The unstable os acromiale: a cause of pain in the young athlete

Purpose

Os acromiale is a common entity in the middle-age group, in whom it is frequently associated with rotator cuff tears. However, it can be a cause of shoulder pain in the young athletes. We want to increase awareness of this pathology that may occultly affect the young athlete as well as to present the results of a perfusion-preserving arthrodesis.

Methods

Four consecutive young patients (17-21 years old) with a history of at least 6 months of unrecognized shoulder pain were surgically treated for os acromiale. Through a superior approach, stabilization of the neo-joint by means of cannulated screws and autogenic graft augmentation was performed.

Results

Union of the os acromiale was achieved in all the patients. They had an excellent functional outcome, reaching all the maximum Simple Shoulder Test (12) and Oxford shoulder Score (48) scores. All the patients were able to return to their previous sports level.

Conclusion

Awareness of the os acromiale in the young athlete, appropriate clinical examination, and image studies are crucial to confirm diagnosis. Surgical treatment aiming at fusion in situ has shown excellent result.

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.

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.

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.

Prebending of osteosynthesis plate using 3D printed models to treat symptomatic os acromiale and acromial fracture

BACKGROUND

A symptomatic os acromiale can lead to impingement syndrome and rotator cuff tendinopathy. An acromion fracture is often part of a more complex scapular trauma that needs stabilisation.

METHODS

We developed a new technique using a three-dimensional (3D) model and a distal clavicle reconstruction plate to treat os acromiale and acromion fractures. Our hypothesis was that such an approach would be a useful addition to the existing techniques. First, a 3D model of the acromion was printed, then an osteosynthesis plate was pre-bent to fit the exact shape and curve of the acromion. We tested this technique and present reports on five patients, three with os acromiales and two with acromial fractures. We followed these patients during their rehabilitation and evaluated them using the Constant-Murley and the Disabilities of the Arm, Shoulder and Hand scores.

RESULTS

In every case the fracture or non-union healed. If the surgery was performed before additional damage (such as an impingement syndrome) occurred, we saw that the patient's pain completely disappeared. This new technique also has other advantages because the surgeon can prepare the entire operation in advance, which reduces the duration of surgery. Another advantage of using a 3D model is that it can also be used to inform the patient and the surgical team about the planned operation.

CONCLUSION

This new technique using a preoperative patient-customized plate is a good alternative for use in open reduction and internal fixation, particularly if the patient has no other conditions.

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.

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.

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.

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.