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Os Acromiale PDF Evidence

A hand-drawn illustration of an anatomical drawing of an os acromiale, the acromion with a separate unfused bony fragment.
Os acromiale: the front portion of the acromion has not fused with the rest of the acromion during skeletal maturation. Kieran Hirpara 4.0

Patient-facing topic on os acromiale — failed fusion of an acromial ossification centre that may cause shoulder pain and contribute to subacromial impingement.

What you're feeling

You may feel pain in the top of your shoulder. This condition affects about 2.13% of patients with shoulder problems who need an MRI. The pain often comes from a tear in the rotator cuff, which is a group of muscles and tendons that move your arm. This tear happens because the extra bone piece moves abnormally and rubs against your other tissues.

Your pain might flare up after you do certain activities. It can also wake you up at night or hurt when you try to sleep on that side. Simple daily tasks can become difficult. You might struggle to reach behind your back to fasten a bra or tuck in a shirt. These movements put pressure on the area where the bone pieces do not fully join together.

If you have had shoulder replacement surgery, you might notice tenderness right over this bone piece. This happens in 1 out of 4 patients after the procedure. The good news is that this soreness usually goes away on its own over time for most people. Your surgeon will check your symptoms to decide if this extra bone piece is the main cause of your pain.

What's actually happening

Your shoulder has a small bone fragment called the os acromiale that hasn't fused to the main bone. This happens in about 2.13% of patients with shoulder problems needing an MRI. Think of this unfused spot as a loose gasket between two parts of your shoulder bone. Instead of moving as one solid piece, this loose fragment can rub and shift when you move your arm.

This abnormal motion often irritates the soft tissues nearby. The rotator cuff is a group of tendons that act like ropes to lift and rotate your arm. Because the loose bone moves strangely, it can pinch these tendons. This pinching, or impingement, often leads to a rotator cuff tear. In young athletes, this specific injury pattern is common and needs careful checking to confirm the diagnosis.

Sometimes this loose bone can get hurt after a fall or injury, though this is rare. If you have surgery for other reasons, like a reverse total shoulder replacement, you might feel local tenderness at this spot in 1 out of 4 patients. This soreness usually goes away on its own over time. Having this extra bone fragment does not seem to hurt your overall results from major shoulder replacement surgery.

What we can do about it

Most people start with self-care and physical therapy to manage pain. Your therapist will guide exercises to strengthen the shoulder muscles and improve movement. This approach aims to reduce friction where the extra bone piece sits. You should give this non-surgical plan a fair trial before considering other steps.

If pain persists, your surgeon may discuss medication or injections. Anti-inflammatory drugs can help reduce swelling and soreness around the joint. In some cases, a cortisone injection is used to calm inflammation quickly. While the evidence does not specify exact durations for these treatments, many patients find relief while the medication works. If you are a competitive athlete, your surgeon will weigh the risks carefully, as surgery is often not recommended for professional tennis players.

Surgery is usually considered only if these conservative measures fail to control your symptoms. The goal of the operation is to remove the unstable bone fragment or fix it in place to stop the painful motion. This decision is made together with your surgeon after reviewing your specific case and imaging results.

When to see someone

See your GP if you have persistent shoulder pain that does not improve with rest. Ask for a specialist review if you notice weakness, instability, or your shoulder locks or gives way. Symptoms that interfere with sleep or work also require attention. Seek help if you experience a sudden worsening of pain. This condition is linked to rotator cuff injuries, which may cause impingement from abnormal motion. While rare, the joint can be injured after trauma. If you are a professional tennis player, surgical treatment is usually not indicated, but a specialist can confirm the diagnosis through examination and imaging.

Reviewed by AI synthesis (v2) — pending human review · 2026-05-18 19:02:24.996868+00:00.

Want the clinical detail? Read the clinician version.

Talk to your treating clinician for advice specific to you.

For an appointment with the CQ Hand + Upper Limb team, ask your GP about a referral or visit www.cqupperlimb.com.

Evidence & references

title: "Os Acromiale" slug: os-acromiale region: shoulder audience: patient mesh_terms: [] article_count: 28 model_used: qwen3.5-35b-a3b-q8 generated_at: '2026-05-18T14:14:36+00:00' key_articles: - title: "Prevalence of Os Acromiale in Thai Patients With Shoulder Problems: A Magnetic Resonance Imaging Study" ref_num: 1 evidence_tier: paper evidence_level: 3 doi: 10.1177/23259671221078806 year: 2022 - title: "Os acromiale: systematic review of surgical outcomes" ref_num: 2 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.jse.2019.05.047 year: 2020 - title: "Os Acromiale in Reverse Total Shoulder Arthroplasty: A Cohort Study" ref_num: 3 evidence_tier: paper evidence_level: 3 doi: 10.1177/2325967120965131 year: 2020 - title: "Clinical implications of reverse total shoulder arthroplasty with an os acromiale: a systematic review" ref_num: 4 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.xrrt.2025.01.002 year: 2025 - title: "Prevalence and factors associated with os acromiale: a multicenter study" ref_num: 5 evidence_tier: paper evidence_level: 3 doi: 10.1016/j.jseint.2025.05.015 year: 2025 - title: "The prevalence and associated factors of os acromiale: a multicenter study" ref_num: 6 evidence_tier: paper evidence_level: 3 doi: 10.1016/j.jse.2025.01.008 year: 2025 - title: "Os Acromiale in Professional Tennis Players" ref_num: 7 evidence_tier: paper evidence_level: 4 doi: 10.1177/2325967118773723 year: 2018 - title: "Rotator cuff tears associated with os acromiale." ref_num: 8 evidence_tier: paper evidence_level: 4 doi: 10.2106/00004623-198466080-00029 year: 1984 - title: "Reverse shoulder arthroplasty in patients with os acromiale" ref_num: 9 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.jse.2017.02.012 year: 2017 - title: "Os Acromiale: Frequency, Anatomy, and Clinical Implications*" ref_num: 10 evidence_tier: paper evidence_level: 4 doi: 10.2106/00004623-200003000-00010 year: 2000 - title: "The unstable os acromiale: a cause of pain in the young athlete" ref_num: 11 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.jseint.2020.02.008 year: 2020 - title: "Os acromiale may be a contraindication of the clavicle hook plate: case reports and literature review" ref_num: 12 evidence_tier: paper evidence_level: 4 doi: 10.1186/s12891-021-04841-1 year: 2021 - title: "Fracture of an os acromiale with associated rupture of the coracoclavicular ligaments" ref_num: 13 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.jse.2008.02.012 year: 2008 - title: "Rare Symptomatic Meta–Os Acromiale in an Athlete" ref_num: 15 evidence_tier: paper evidence_level: 4 doi: 10.1177/03635465211028238 year: 2021 - title: "Symptomatic, Unstable Os Acromiale" ref_num: 16 evidence_tier: paper evidence_level: 5 doi: 10.5435/jaaos-d-17-00011 year: 2018 - title: "Arthroscopically assisted internal fixation of the symptomatic unstable os acromiale with absorbable screws" ref_num: 17 evidence_tier: paper evidence_level: 4 doi: 10.1016/j.jse.2011.12.011 year: 2012 - title: "Os acromiale: a review of its incidence, pathophysiology, and clinical management" ref_num: 19 evidence_tier: paper evidence_level: 4 doi: 10.1302/2058-5241.4.180100 year: 2019 - title: "Surgical Stabilization of Os Acromiale in a Fast-Pitch Softball Pitcher" ref_num: 21 evidence_tier: paper evidence_level: 4 doi: 10.1177/0363546506288305 year: 2006 - title: "Reverse shoulder arthroplasty with os acromiale" ref_num: 24 evidence_tier: paper evidence_level: 4 doi: 10.5397/cise.2019.00409 year: 2020 synthesis_version: "v2" verifier_status: skipped

Overview

  • In Thai patients with shoulder problems requiring MRI evaluation, the prevalence of os acromiale was 2.13% [1].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A multicenter study aimed to determine the prevalence of and factors associated with os acromiale in the Japanese population [6].
  • Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes [2].
  • Surgical options for symptomatic os acromiale include arthroscopic sub-total excision [16].
  • Surgical options for symptomatic os acromiale include arthroscopic subacromial decompression of stable fragments [16].
  • Surgical options for symptomatic os acromiale include open reduction and internal fixation of unstable fragments [16].
  • Surgical treatment is usually not indicated for os acromiale in the professional tennis player [7].
  • Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate [12].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients after reverse total shoulder arthroplasty [3].
  • Postoperative local tenderness at the os acromiale resolves spontaneously over time in the majority of patients after reverse total shoulder arthroplasty [3].
  • The presence of os acromiale does not appear to have a negative impact on clinical outcomes after reverse total shoulder arthroplasty [4].
  • The outcome of reverse total shoulder arthroplasty does not seem to be negatively affected by the presence of an os acromiale [9].

Anatomy & Pathophysiology

  • The prevalence of os acromiale in Thai patients with shoulder problems requiring MRI evaluation is 2.13% [1].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site [8].
  • Fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting [10].
  • Awareness of the os acromiale in the young athlete is crucial to confirm diagnosis through appropriate clinical examination and image studies [11].
  • The synchondrosis of an os acromiale can be injured following trauma, though rarely [13].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients after reverse total shoulder arthroplasty [3].
  • Postoperative local tenderness at the os acromiale resolves spontaneously over time in the majority of patients [3].
  • The presence of os acromiale does not appear to have a negative impact on clinical outcomes after reverse total shoulder arthroplasty [4].
  • The outcome of reverse total shoulder arthroplasty does not seem to be negatively affected by the presence of an os acromiale [9].
  • Reverse shoulder arthroplasty improves range of motion, decreases pain, and increases patient satisfaction in patients with os acromiale and cuff tear arthropathy [24].
  • Surgical treatment is usually not indicated for os acromiale in the professional tennis player [7].

Classification

  • The prevalence of os acromiale in Thai patients with shoulder problems requiring MRI evaluation is 2.13% [1].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site [8].
  • Fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting [10].
  • Awareness of the os acromiale in the young athlete, appropriate clinical examination, and image studies are crucial to confirm diagnosis [11].
  • The synchondrosis of an os acromiale can be injured following trauma, though rarely [13].
  • Meta-os acromiale is the rarest subtype of os acromiale [15].

Clinical Presentation

  • The prevalence of os acromiale in Thai patients with shoulder problems requiring MRI evaluation was 2.13% [1].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site [8].
  • The presence of os acromiale does not appear to have a negative impact on clinical outcomes after reverse total shoulder arthroplasty (rTSA) [4].
  • The outcome of reverse total shoulder arthroplasty (RTSA) does not seem to be negatively affected by the presence of an os acromiale [9].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients following rTSA [3].
  • Postoperative local tenderness at the os acromiale resolves spontaneously over time in the majority of patients [3].
  • Surgical treatment is usually not indicated for os acromiale in professional tennis players [7].
  • Awareness of the os acromiale, appropriate clinical examination, and image studies are crucial to confirm diagnosis in young athletes [11].
  • Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate [12].
  • The synchondrosis of an os acromiale can be injured following trauma, though rarely [13].
  • Fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting [10].
  • Meta-os acromiale is the rarest subtype of os acromiale [15].
  • Liberson reviewed 1800 shoulder girdles and identified an incidence of os acromiale of 1.4% [14].
  • The lesion of os acromiale is bilateral in 62% of patients according to Liberson's review [14].

Investigations

  • The prevalence of os acromiale in Thai patients with shoulder problems requiring MRI evaluation is 2.13% [1].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site [8].
  • Awareness of the os acromiale in the young athlete, appropriate clinical examination, and image studies are crucial to confirm diagnosis [11].
  • The synchondrosis of an os acromiale can be injured following trauma, though rarely [13].
  • Appropriate radiographic investigation for os acromiale injury includes axillary views [13].
  • Fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting [10].
  • Liberson reviewed 1800 shoulder girdles and identified an incidence of os acromiale of 1.4% [14].
  • The lesion of os acromiale is bilateral in 62% of patients according to Liberson's review [14].

Treatment

  • Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes [2].
  • Surgical options for symptomatic os acromiale include arthroscopic sub-total excision, arthroscopic subacromial decompression of stable fragments, and open reduction and internal fixation of unstable fragments [16].
  • 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 [19].
  • A new arthroscopic technique of fixation of os acromiale with absorbable screws provides promising clinical, cosmetic, and radiologic results with high patient satisfaction [17].
  • A symptomatic os acromiale in a competitive female fastball pitcher was treated successfully with open reduction and internal fixation [21].
  • Special consideration must be given to the type of tension-band construct used to achieve adequate compression and fixation for meta-os acromiale, the rarest subtype of os acromiale [15].
  • Surgical treatment is usually not indicated for os acromiale in the professional tennis player [7].
  • Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate [12].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients but resolves spontaneously over time in the majority of patients [3].
  • The presence of os acromiale does not appear to have a negative impact on the clinical outcomes after reverse total shoulder arthroplasty (rTSA) [4].
  • The outcome of reverse total shoulder arthroplasty (RTSA) does not seem to be negatively affected by the presence of an os acromiale [9].

Complications

  • The prevalence of os acromiale in Thai patients with shoulder problems requiring MRI evaluation was 2.13% [1].
  • Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes [2].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients following reverse total shoulder arthroplasty [3].
  • Postoperative local tenderness at the os acromiale resolves spontaneously over time in the majority of patients [3].
  • The presence of os acromiale does not appear to have a negative impact on clinical outcomes after reverse total shoulder arthroplasty [4].
  • Reverse total shoulder arthroplasty remains a safe and effective treatment option in the presence of os acromiale [4].
  • Os acromiale is associated with rotator cuff injuries [5].
  • A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site [8].
  • Surgical treatment is usually not indicated for os acromiale in professional tennis players [7].
  • Fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting [10].
  • The incidence of os acromiale identified by Liberson was 1.4% [14].
  • The lesion of os acromiale was bilateral in 62% of patients in Liberson's review [14].

Recovery

  • Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes [2].
  • Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients but resolves spontaneously over time in the majority of patients [3].
  • The presence of os acromiale does not appear to have a negative impact on the clinical outcomes after reverse total shoulder arthroplasty (rTSA) [4].
  • Reverse total shoulder arthroplasty (rTSA) remains a safe and effective treatment option in patients with os acromiale [4].
  • The outcome of reverse total shoulder arthroplasty (RTSA) does not seem to be negatively affected by the presence of an os acromiale [9].
  • Surgical treatment is usually not indicated for os acromiale in professional tennis players [7].

Key Evidence

  • [L3] In Thai patients with shoulder problems who required MRI evaluation, the prevalence of os acromiale was 2.13%. (10.1177/23259671221078806)
  • [L4] Operative management of a symptomatic os acromiale that has failed initial nonoperative treatment leads to decreased symptoms and improvement in clinical outcomes. (10.1016/j.jse.2019.05.047)
  • [L3] Postoperative local tenderness at the os acromiale can be expected in 1 out of 4 patients but resolves spontaneously over time in the majority of patients. (10.1177/2325967120965131)
  • [L4] The presence of os acromiale does not appear to have a negative impact on the clinical outcomes after surgery and rTSA remains a safe and effective treatment option. (10.1016/j.xrrt.2025.01.002)
  • [L3] The study supports previous findings that os acromiale is associated with rotator cuff injuries. (10.1016/j.jseint.2025.05.015)
  • [L3] This multicenter study aimed to determine the prevalence of and factors associated with os acromiale in the Japanese population. (10.1016/j.jse.2025.01.008)
  • [L4] Surgical treatment is usually not indicated for os acromiale in the professional tennis player. (10.1177/2325967118773723)
  • [L4] A tear of the rotator cuff may often be associated with os acromiale, likely due to impingement from abnormal motion at the fibrous union site. (10.2106/00004623-198466080-00029)
  • [L4] The outcome of RTSA does not seem to be negatively affected by the presence of an os acromiale. (10.1016/j.jse.2017.02.012)
  • [L4] An anatomical study showed that fused os acromiale, which has not been described previously, might be mistaken for a free ossicle in the clinical setting. (10.2106/00004623-200003000-00010)
  • [L4] Awareness of the os acromiale in the young athlete, appropriate clinical examination, and image studies are crucial to confirm diagnosis. (10.1016/j.jseint.2020.02.008)
  • [L4] Ipsilateral os acromiale may be a relative contraindication to the clavicle hook plate. (10.1186/s12891-021-04841-1)
  • [L4] This case highlights that the synchondrosis of an os acromiale can be injured following trauma, though rarely, and emphasizes the need for appropriate radiographic investigation including axillary views and a flexible surgical approach. (10.1016/j.jse.2008.02.012)
  • [L4] Meta–os acromiale is the rarest subtype of os acromiale, and special consideration must be given to the type of tension-band construct used to achieve adequate compression and fixation. (10.1177/03635465211028238)
  • [L5] Surgical options for symptomatic os acromiale include arthroscopic sub-total excision, arthroscopic subacromial decompression of stable fragments, and open reduction and internal fixation of unstable fragments. (10.5435/jaaos-d-17-00011)
  • [L4] This new arthroscopic technique of fixation of os acromiale with absorbable screws provides promising clinical, cosmetic, and radiologic results with high patient satisfaction. (10.1016/j.jse.2011.12.011)
  • [L4] 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. (10.1302/2058-5241.4.180100)
  • [L4] A symptomatic os acromiale in a competitive female fastball pitcher was treated successfully with open reduction and internal fixation. (10.1177/0363546506288305)
  • [L4] Reverse shoulder arthroplasty improved ROM, decreased pain, and increased patient satisfaction in patients with os acromiale and cuff tear arthropathy. (10.5397/cise.2019.00409)

References

[1] Prevalence of Os Acromiale in Thai Patients With Shoulder Problems: A Magnetic Resonance Imaging Study. Orthopaedic Journal of Sports Medicine. 2022. DOI: 10.1177/23259671221078806 [2] Os acromiale: systematic review of surgical outcomes. Journal of Shoulder and Elbow Surgery. 2020. DOI: 10.1016/j.jse.2019.05.047 [3] Os Acromiale in Reverse Total Shoulder Arthroplasty: A Cohort Study. Orthopaedic Journal of Sports Medicine. 2020. DOI: 10.1177/2325967120965131 [4] Clinical implications of reverse total shoulder arthroplasty with an os acromiale: a systematic review. JSES Reviews, Reports, and Techniques. 2025. DOI: 10.1016/j.xrrt.2025.01.002 [5] Prevalence and factors associated with os acromiale: a multicenter study. JSES International. 2025. DOI: 10.1016/j.jseint.2025.05.015 [6] The prevalence and associated factors of os acromiale: a multicenter study. Journal of Shoulder and Elbow Surgery. 2025. DOI: 10.1016/j.jse.2025.01.008 [7] Os Acromiale in Professional Tennis Players. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118773723 [8] Rotator cuff tears associated with os acromiale.. The Journal of Bone & Joint Surgery. 1984. DOI: 10.2106/00004623-198466080-00029 [9] Reverse shoulder arthroplasty in patients with os acromiale. Journal of Shoulder and Elbow Surgery. 2017. DOI: 10.1016/j.jse.2017.02.012 [10] Os Acromiale: Frequency, Anatomy, and Clinical Implications. The Journal of Bone and Joint Surgery-American Volume. 2000. DOI: 10.2106/00004623-200003000-00010 [11] The unstable os acromiale: a cause of pain in the young athlete. JSES International. 2020. DOI: 10.1016/j.jseint.2020.02.008 [12] Os acromiale may be a contraindication of the clavicle hook plate: case reports and literature review. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04841-1 [13] Fracture of an os acromiale with associated rupture of the coracoclavicular ligaments. Journal of Shoulder and Elbow Surgery. 2008. DOI: 10.1016/j.jse.2008.02.012 [14] Types of os acromiale according to Liberson. 2006. [15] Rare Symptomatic Meta–Os Acromiale in an Athlete. The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211028238 [16] Symptomatic, Unstable Os Acromiale. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-17-00011 [17] Arthroscopically assisted internal fixation of the symptomatic unstable os acromiale with absorbable screws. Journal of Shoulder and Elbow Surgery. 2012. DOI: 10.1016/j.jse.2011.12.011 [19] Os acromiale: a review of its incidence, pathophysiology, and clinical management. EFORT Open Reviews. 2019. DOI: 10.1302/2058-5241.4.180100 [21] Surgical Stabilization of Os Acromiale in a Fast-Pitch Softball Pitcher. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546506288305 [24] Reverse shoulder arthroplasty with os acromiale. Clinics in Shoulder and Elbow*. 2020. DOI: 10.5397/cise.2019.00409

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a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.