Elsevier

Journal of Shoulder and Elbow Surgery

Volume 11, Issue 5, September–October 2002, Pages 521-528
Journal of Shoulder and Elbow Surgery

Review article
Surgical management of the symptomatic os acromiale*

https://doi.org/10.1067/mse.2002.122227Get rights and content

Abstract

Os acromiale is an uncommon cause of shoulder pain with symptoms often resulting from an unstable meso-acromion. The associated pain may be due to impingement from the unfused fragment, a concomitant rotator cuff tear, or gross motion at the os acromiale site. Currently, initial treatment includes physical therapy, nonsteroidal anti-inflammatory agents, and subacromial corticosteroid injections. Surgical intervention is reserved for patients who do not respond to nonoperative treatment. Treatment options include open fragment excision, open reduction and internal fixation, and arthroscopic decompression. Open fragment excision can lead to persistent deltoid dysfunction and should be reserved for small fragments or after failed internal fixation. Open reduction and internal fixation allows for both preservation of large fragments and anterior deltoid function. Internal fixation is technically difficult, has led to frequent nonunion rates and often requires hardware removal as a result of postoperative irritation. Arthroscopic subacromial decompression with complete or nearly complete resection of the unstable meso-acromion can be performed without the aforementioned complications. The surgical technique requires no special instrumentation and may be performed reproducibly by those familiar with arthroscopic techniques of the shoulder. Advantages include more rapid rehabilitation, better range of motion, and shorter surgical times. Satisfactory short-term results have shown this to be an effective treatment option for the unstable meso-acromion. (J Shoulder Elbow Surg 2002;11:521-8)

Section snippets

Anatomy

The acromion develops from 3 separate ossification centers. The preacromion, meso-acromion, and meta-acromion typically fuse to each other between the 15th and 18th year10 (Figure 1).

. Drawing of ossification centers and potential sites of os acromiale formation.

Osseous union between the acromial apophysis and the spine of the scapula may occur as late as the 25th year. Persistence of the unfused acromial apophysis is called an os acromiale. Failure of ossification is most common between the

Diagnosis

Patients frequently describe symptoms similar to subacromial impingement,19 including difficulty in overhead activities and trouble sleeping on the affected side. Physical examination reveals positive impingement signs, rotator cuff weakness, and loss of active forward elevation. Furthermore most patients will have pain on palpation directly over the acromion in the region of the os acromiale, and gross motion is occasionally detectable.28 Although symptoms may occur after minor or repetitive

Treatment options

All patients with a symptomatic unstable os acromiale should be given a trial of conservative treatment for at least 6 months. Physiotherapy similar to a standard subacromial impingement protocol should be prescribed in addition to nonsteroidal anti-inflammatory agents and 1 to 2 subacromial corticosteroid injections over a 6-month period. The regimen will allow some patients to avoid surgical intervention. Contraindications to these guidelines include large or acute rotator cuff tears that may

Summary

Treatment options for the unstable meso-acromion include fragment excision, open reduction internal fixation, and arthroscopic subacromial decompression. Open excision has had mixed results primarily related to deltoid dysfunction. In addition, open reduction internal fixation is technically difficult, has a moderate nonunion rate, and often requires reoperation for hardware irritation. In contrast, arthroscopic subacromial decompression with complete or nearly complete resection of the

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  • Cited by (36)

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      Table II lists the complications. Surgical treatment of symptomatic os acromiale is well documented, with various techniques ranging from excision to acromioplasty through to fusion.1,5,7,10-12,14,15 Fusion of the os acromiale has been associated with variable results in union rates and function.

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      The clinical relevance of this finding remains unclear as the loading that acts on the repair site due to the deltoid muscle contraction is unknown. However, a wide range of union rates after surgical repair of os acromiale (25% to 100%) has been reported,1,13,21 perhaps indicating that some techniques were not able to produce sufficient biomechanical stability. Furthermore, more stable fixation would theoretically permit a more aggressive postoperative rehabilitation protocol.

    • Acromion reconstruction after failed subacromial decompression in shoulders with os acromiale (meso-acromion): The tongue-and-groove assembly

      2014, Journal of Shoulder and Elbow Surgery
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      Various options have been reported in the treatment of symptomatic os acromiale, including open excision of the bone fragment,3,12,18 arthroscopic acromioplasty (resulting in complete or nearly complete excision of the fragment),19 or open fixation and bone grafting.9,16,18 Arthroscopic subacromial decompression has yielded variable results from satisfactory to unsatisfactory outcomes.10,15,19 Open fixation–internal fixation with concomitant bone grafting is the most-documented treatment option.

    • Os acromiale. A review and an introduction of a new surgical technique for management.

      2013, Orthopedic Clinics of North America
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      Because complications arise from the fragment excision, many surgeons advocate internal fixation of the unfused os acromiale with bone grafting. Techniques to provide stability include the use of tension-band wires, sutures, or cannulated screws with or without the use of bone graft.34 Peckett and colleagues3 reviewed 26 patients presenting with symptomatic meso os acromiale that were treated with either K-wires or screws and a tension band.

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

      2013, Orthopaedics and Traumatology: Surgery and Research
      Citation Excerpt :

      A painless os acromiale becomes symptomatic when it is unstable. The diagnosis of painful os acromiale in the presence of scapulalgia is based on a radiological and clinical examination that should confirm the role of os acromiale as the source of pain [21] and exclude the main differential diagnoses [22] (rotator cuff damage and subacromial impingement of an “aggressive” acromion). A causative factor should be looked for including direct or indirect trauma to the shoulder or a history of surgery, even if this is not always found (four cases in our series, two cases in the series by Pagnani et al. [11] and 58% in the series by Abboud et al. [23]).

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