Skip to content

Patients › Ankle

Charcot neuroarthropathy

PDF Evidence
Updated Sep 2026
Illustration: ankle

Ang pahinang ito ay isinalin ng makina at hindi pa nasusuri ng isang doktor. Ang bersyong Ingles ang siyang opisyal.

Ang iyong nararamdaman

Ang Charcot neuroarthropathy ay nakakaapekto sa mga taong nawalan ng bahagi ng pakiramdam sa kanilang mga paa, kadalasan dahil sa diabetes. Dahil hindi nararamdaman ng mga kasukasuan (joints) ang strain sa paraang dapat, ang paglalakad at pagtayo ay maaaring tahimik na makapinsala sa mga ito. Ang kasukasuan ay nagiging namamagâ, mainit at mapula, at ang paa ay maaaring magsimulang magbago ng hugis. Maraming tao ang nakapapansin ng kaunting sakit lamang sa simula, na bahagi ng dahilan kung bakit madaling makaligtaan ang kondisyong ito.

Kapag may discomfort, karaniwan itong nararamdaman sa gitna ng paa o sa bukung-bukong (ankle). Madalas itong lumalala pagkatapos ng oras na nakatayo, at maaaring mas malala sa gabi o kapag bagong gising. Ang pahinga ay nakakatulong upang kumalma ito, ngunit ang pamamaga ay maaaring matagalan bago humupa. Habang nagbabago ang hugis ng paa, nagiging mas mahirap ang mga pang-araw-araw na gawain: ang mga sapatos ay maaaring kumiskis o hindi na kasya, ang pagtayo sa bench para magluto ay nakakapagod, at ang paglalakad papunta sa letterbox o sa mga tindahan ay maaaring maramdamang hindi matatag. Ang ilang tao ay nagkakaroon ng rocker-bottom shape sa paa, kung saan ang arch ay naging patag at bumagsak, at ang mga pressure point ay maaaring maging mga ulcer sa talampakan.

Inaalam ng iyong surgeon kung ano ang nangyayari sa pamamagitan ng pakikinig sa iyong mga sintomas at pagsusuri sa iyong paa, pagkatapos ay itutugma ang iyong nararamdaman sa kanilang natuklasan. Kung ang iyong kwento at ang pagsusuri ay hindi tugma, ang mga karagdagang scan tulad ng CT o MRI ay maaaring makatulong upang malaman ang sanhi. Ang mga buto sa apektadong paa ay maaari ring numipis, na nagpapataas ng panganib ng pagkakaroon ng maliliit na bali (breaks) sa mismong kasukasuan.

Kung ikaw ay may diabetes at nakapansin ng mainit at namamagang paa na may kaunti o walang sakit, mahalagang maipasuri ito agad. Ang maagang diagnosis ay nagbibigay sa iyong paa ng pinakamahusay na pagkakataon na manatiling matatag.

Ano ang aktwal na nangyayari

Ang Charcot neuroarthropathy ay nangyayari kapag ang isang joint ay nawawalan ng proteksyong karaniwang ibinibigay ng pakiramdam. Ang mga malulusog na joint ay nagpapadala ng mga babalang signal kapag ang mga ito ay sobra ang karga, kaya ikaw ay nagpapahinga, nagpapalit ng sapatos, o nag-aalis ng bigat mula sa masakit na bahagi. Kapag wala ang mga signal na iyon, patuloy na sumasalo ng karga ang joint. Nagpapatong-patong ang mga maliliit na pinsala, at ang buto ay nagsisimulang masira at magbago ng hugis.

Dalawang bagay ang tila nangyayari sa loob ng joint. Ang isa ay ang pagkapudpod nang walang karaniwang warning system: dahil hindi mo nararamdaman ang strain, patuloy kang naglalakad gamit ang isang joint na ipapahinga sana ng isang taong may normal na sensation. Ang isa naman ay ang mga pagbabago sa daloy ng dugo sa loob ng buto, na maaaring magpahina rito mula sa loob. Sa isang active Charcot foot, ang mga cell na sumisira sa lumang buto ay nagiging mas aktibo habang ang mga cell na bumubuo ng bagong buto ay hindi nakakasabay. Ang buto ay nagiging mas manipis at mas mahina, kung kaya't maaaring mangyari ang mga maliliit na bali sa mismong joint.

Ang mga joint na madalas maapektuhan ay nasa gitna ng paa at sa ankle, kung saan ang mga buto at ligament ay karaniwang humahawak sa lahat sa isang stable na frame. Ang mga ligament ay malalakas na band na nagkokonekta ng buto sa buto at nagpapanatili sa alignment ng joint habang ikaw ay naglalakad. Habang lumalambot ang buto at nababanat ang mga ligament, ang frame na iyon ay nagsisimulang bumigay. Ang arch ay maaaring pumapatag at gumuho patungo sa rocker-bottom shape na inilarawan kanina, at ang mga joint ay maaaring mawala sa alignment. Dahil kakaunti o walang sakit na magbabala sa iyo, ang pinsala ay maaaring unti-unting maipon nang tahimik hanggang sa magbago ang hugis ng paa o masira ang balat.

Walang sinuman ang lubos na nakakaunawa kung bakit ito nangyayari, at malamang na higit sa isang mekanismo ang gumagana. Ang mahalaga para sa iyo ay ang praktikal na punto: ang isang joint na hindi nakakaramdam ng pinsala ay hindi kayang protektahan ang sarili, kaya ang pamamaga, init, at pagbabago sa hugis na iyong napapansin ay mga palatandaan ng isang joint na tahimik na na-overload.

Ano ang maaari naming gawin tungkol dito

Ang unang hakbang ay ang pagbabawas ng bigat (weight) mula sa mga apektadong joint upang hindi na sila ma-overload. Maaari kaming magmungkahi ng mga pagbabago sa iyong aktibidad, at mga orthotics, na mga device na isinusuot sa loob o sa ibabaw ng iyong mga sapatos upang suportahan at protektahan ang paa. Ang mga orthotic device ay maaaring magkaroon ng tunay na epekto sa kung gaano kahusay gumagana ang iyong paa sa araw-araw. Layunin ng physiotherapy na panatilihin kang gumagalaw nang ligtas habang pinoprotektahan ang mga joint na nawalan na ng kanilang mga warning signal. Binibigyan namin ang approach na ito ng sapat na pagsubok bago pag-usapan ang anumang susunod na hakbang.

Ang pain relief at anti-inflammatory medicine ay maaaring makatulong na pagaanin ang discomfort sa short term. Ginagamit namin ang mga ito kasabay ng mga hakbang sa itaas, hindi bilang kapalit ng mga ito.

Kung ang mga hakbang na ito ay hindi nagbigay ng sapat na pagbuti, maaari naming talakayin ang operasyon. Ang pangunahing opsyon ay arthrodesis, na nangangahulugang pagdurugtong sa mga apektadong buto upang ang paa o bukung-bukong (ankle) ay maging stable at mapanatili ang hugis nito habang may weight-bearing. Ang isang stable at flat-on-the-ground na paa ay lubos na nagbabawas ng pagkakataon na bumalik ang mga ulcer at impeksyon sa talampakan. Sa ilang mga kaso, gumagamit kami ng rod na inilalagay pababa mula sa bukung-bukong patungo sa sakong upang panatilihin ang mga buto sa kanilang posisyon habang sila ay nagdurugtong. Kung kailangan ng karagdagang suporta, maaari kaming magdagdag ng bone graft, na buto na kinuha mula sa iyong sariling katawan upang tulungan ang mga buto na gumaling nang magkasama. Ang operasyon ay isang shared decision, at pag-uusapan namin kung ito ay angkop para sa iyong paa at sa iyong mga layunin.

Ano ang dapat asahan

Ang Charcot neuroarthropathy ay isang pangmatagalang kondisyon. Ang pamamaga at init sa isang aktibong paa ay karaniwang humuhupa sa loob ng ilang linggo hanggang buwan, lalo na kapag inalis na ang bigat sa kasukasuan. Ngunit ang mga pagbabago sa hugis ng paa ay madalas na nananatili. Kung walang gamutan, patuloy na tumatanggap ng karga ang kasukasuan na hindi nito nararamdaman, at ang pinsala ay tahimik na naiipon hanggang sa maging unstable ang paa o ang balat ay magkaroon ng mga ulcer.

Sa pamamagitan ng maayos na pangangalaga, maraming paa ang nananatiling stable at magagamit. Ang mga orthotics at iba pang non-operative na hakbang ay maaaring magdulot ng malaking pagkakaiba sa araw-araw na paggana ng iyong paa. Kung kinakailangan ang operasyon, ang pagsasama ng mga apektadong buto ay nagbibigay ng stable na paa sa karamihan ng mga kaso, kung saan ang mga buto ay matagumpay na nagsasama sa higit sa 80% ng mga hindfoot reconstruction. Sa pangkalahatan, ang operasyon upang itama ang malalang deformity ay nagreresulta sa stability sa 93% ng mga pasyente. Karamihan sa mga taong sumailalim sa ganitong uri ng operasyon ay nag-uulat ng mas mabuting pagkawala ng sakit at mas mabuting function, at nasisiyahan sa resulta sa loob ng maraming taon pagkatapos nito.

Katapatan na sabihin na ang operasyon sa paang nawalan ng pakiramdam ay mapanghamon. Minsan ay nabibigong magsama ang mga buto, at maaaring mangyari ang impeksyon o mga problema sa sugat, lalo na sa mga taong may diabetes, mahinang sirkulasyon ng dugo sa balat, o sa mga naninigarilyo. Mahalaga ang maingat na pagpili, at ang operasyon ay karaniwang isang salvage option para sa mga paang hindi humupa sa pamamagitan ng iba pang mga hakbang. Sa maliit na bilang ng mga kaso, hindi na posible ang pagliligtas sa limb at amputation ang tinatalakay sa halip.

Ang maaari mong makatotohanang asahan ay ito: sa pamamagitan ng maagang diagnosis, proteksyon mula sa overload, at isang team approach, karamihan sa mga paa ay maaaring mapanatiling stable at komportable. Habang mas maagang natutukoy ang kondisyon, mas napapanatili ang hugis at function ng iyong paa.

Kailan dapat magpatingin

Sa Charcot neuroarthropathy, ang mga babalang senyales ay hindi ang mga karaniwan. Ang mainit, namamagang, at pulang paa na may kaunti o walang sakit ang senyales na mahalaga, at kailangan itong masuri agad sa halip na maghintay kung ito ay huhupa. Mas mahalaga ito kung mayroon kang diabetes, dahil ang paang nawalan ng pakiramdam ay hindi makakapagbabala sa iyo tungkol sa pinsala gaya ng dapat nito. Humingi ng pagsusuri ng isang espesyalista kung ang ulcer sa paa ay hindi gumagaling, kung nagbabago ang hugis ng iyong paa, o kung may napapansin kang bagong pamamanhid o tila tinutusok ng mga karayom (pins and needles) sa iyong mga paa. Pumunta sa emergency department kung ang iyong paa ay biglang naging napakasakit, malalang namaga, o kung ang balat ay nasisira na may kumakalat na pamumula, dahil ang mga ito ay maaaring mangahulugan ng isang problema na nangangailangan ng pangangalaga sa mismong araw na iyon.

Reviewed by AI synthesis (v2) — pending human review · 9 September 2026.

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

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Anatomy & Pathophysiology

Bony Anatomy

  • The ankle mortise is formed by the tibial plafond, medial malleolus, and lateral malleolus [3].
  • The ankle mortise articulates with the dome of the talar body [3].
  • The talar dome is wider anteriorly and narrower posteriorly [3].
  • The ankle mortise widens 1 to 1.5 mm during motion from plantar flexion to dorsiflexion [3].
  • Medial and superior clear spaces appear wider with the foot in plantar flexion [3].
  • The distal fibula has a convex medial surface that articulates with the concave incisura fibularis of the distal lateral tibia [3].
  • The fibula rotates approximately 2 degrees within the incisura during ankle motion and ambulation [3].
  • Ankle dorsiflexion results in external rotation and proximal translation of the fibula [3].
  • The primary functions of the foot and ankle are to provide weight-bearing support and forward ambulation [3].

Ligamentous Anatomy

  • The lateral ankle ligaments function as restraints to varus and inversion forces at the ankle [3].
  • The anterior talofibular ligament (ATFL) originates from the anteroinferior aspect of the lateral malleolus, 1 cm proximal to its tip, and extends to the lateral aspect of the talar neck [3].
  • The calcaneofibular ligament (CFL) extends from the tip of the lateral malleolus to the lateral aspect of the calcaneus [3].
  • The posterior talofibular ligament (PTFL) extends from the posterior lateral malleolus to the posterolateral talus [3].
  • The ATFL is the weakest ankle ligament [3].
  • The PTFL is the strongest ankle ligament [3].
  • The distal tibiofibular joint (ankle syndesmosis) and fibula provide stability against lateral talar translation [3].
  • The deltoid ligament complex is the primary ankle stabilizer during stance [3].
  • The deep deltoid ligament extends from the apex of the medial malleolus to the medial talar body [3].
  • The deep deltoid ligament functions primarily to resist lateral talar translation and external rotation [3].
  • The posterior deep deltoid is the most important component of the deep deltoid ligament [3].
  • The superficial deltoid ligament extends from the distal medial malleolus to the navicular bone, sustentaculum tali of the calcaneus, medial talus, and spring ligament [3].
  • The superficial deltoid ligament functions primarily to resist valgus and eversion ankle forces [3].
  • The deltoid ligament consists of superficial and deep layers, with at most six bands, of which only three are constant: the tibionavicular ligament, tibiospring ligament, and deep posterior tibiotalar ligament [8].
  • The superficial layer of the deltoid ligament originates from the anterior malleolus and inserts into the navicular, neck of the talus, sustentaculum tali, and posteromedial talar tubercle [8].
  • The tibiocalcaneal portion of the superficial deltoid ligament is the strongest component and resists eversion of the calcaneus [8].
  • The deep portion of the deltoid ligament is organized into two short, thick, discrete bands: the anterior and posterior deep tibiotalar ligaments [8].
  • The anterior and posterior deep tibiotalar ligaments are intra-articular but extrasynovial [8].
  • The deep posterior band comprises the largest band of the deltoid complex [8].
  • The anterior deep tibiotalar ligament arises from the anterior malleolus and attaches to the medial aspect of the talus [8].
  • The posterior deep tibiotalar ligament originates from the posterior malleolus and inserts on the medial body of the talus [8].
  • The deltoid ligament has a rich vascular supply from three extraosseous sources: the medial tarsal artery, posterior tibial artery, and tibialis anterior artery [8].
  • The deltoid ligament also has an intraosseous vascular supply from either the talus or the medial malleolus [8].
  • The deep deltoid ligament has the highest load to failure at 713.8 N ± 69.3 compared with the lateral collateral ligaments [8].
  • The dominant mode of failure for the deep deltoid ligament is an intrasubstance rupture near its talar insertion [8].
  • The dominant mode of failure for the superficial deltoid ligament is at its insertion on the anterior malleolus [8].

Biomechanics

  • The ankle joint is responsible for most sagittal plane motion of the foot and ankle [3].
  • Ankle plantar flexion ranges from 23 to 48 degrees [3].
  • Ankle dorsiflexion ranges from 10 to 23 degrees [3].
  • The ankle joint also contributes to inversion, eversion, and rotation [3].
  • A simplified model of the ankle joint has a horizontal axis from anteromedial to posterolateral [3].
  • A simplified model of the ankle joint has a coronal axis from superomedial directed distally and laterally to the tip of the fibula [3].
  • The deltoid ligament, specifically the tibiocalcaneal ligament, primarily prohibits eversion and abduction [8].
  • The deep deltoid ligament, primarily the deep posterior tibiotalar ligament, resists external rotation when the foot is dorsiflexed [8].
  • The deep deltoid ligament is responsible for the greatest restraint against lateral translation [8].
  • Valgus tilting of the talus within the mortise requires complete rupture of both the superficial and deep deltoid ligaments [8].

Neurovascular Anatomy

  • The superficial peroneal nerve penetrates the deep fascia and lies subcutaneously 8 to 10 cm proximal to the tip of the lateral malleolus, anterior to the subcutaneous border of the fibula shaft [6].
  • The deep peroneal nerve accompanies the anterior tibial artery between the tendons of the anterior tibial and extensor digitorum longus muscles [6].
  • The deep peroneal nerve lies just lateral to the anterior tibial artery and just lateral to the extensor hallucis longus tendon [6].
  • The saphenous nerve is located just medial or posterior to the saphenous vein in a slightly deeper plane, 3 to 5 cm proximal to the tip of the medial malleolus [6].
  • The anterior tibial artery can usually be palpated beneath the superior extensor retinaculum 4 to 5 cm proximal to the distal articular surface of the tibia [6].
  • The peroneal tendons and superficial peroneal nerve are at the highest risk during intramedullary nailing of distal fibular fractures [11].
  • An accessory incision for arthroscopic repair of the lateral ligament should not surpass 22 mm distance from the lateral malleolus in the anterior direction to avoid damaging the superficial peroneal nerve [11].

Fracture Classification

  • The Danis–Weber Type A classification describes a transverse fracture of the fibula below the tibiofibular syndesmosis, sometimes associated with an oblique or vertical fracture of the medial malleolus [7].
  • The Danis–Weber Type B classification describes an oblique fracture of the fibula in the sagittal plane at the level of the syndesmosis, often accompanied by an avulsion injury on the medial side [7].
  • The Danis–Weber Type C classification describes a fracture above the level of the syndesmosis, indicating that the tibiofibular ligament and part of the interosseous membrane must have been torn [7].
  • To achieve a reduced ankle, the fibula must be restored to its full length [7].
  • To achieve a reduced ankle, the talus must sit squarely in the mortise with no tilt [7].
  • To achieve a reduced ankle, the medial joint space must be restored to its normal width [7].
  • To achieve a reduced ankle, there must be no tibiofibular diastasis [7].

Investigations

General Imaging Principles

  • Advanced imaging is often helpful in diagnosis when combined with a thorough clinical examination [15].
  • MRI is sensitive for all osteochondral lesions of the ankle, but the edema pattern frequently overestimates the severity of injury [12, 13].
  • Linear fluid signal deep to subchondral bone on MRI indicates an unstable osteochondral injury [12, 13].
  • MRI has a sensitivity of 92% for predicting stable versus unstable osteochondral lesions [12, 13].

Osteochondral Lesions

  • Osteochondral lesions are seen in up to 70% of ankle sprains and 75% of ankle fractures [12, 13].
  • The most common location for osteochondral lesions is the medial talar dome [12, 13].
  • Modern data prove that the most common location for medial talar dome osteochondral lesions is central [12, 13].
  • Medial talar dome osteochondral lesions are larger and deeper than lateral lesions [12, 13].
  • The most common location for lateral talar dome osteochondral lesions is central [12, 13].
  • Lateral talar dome osteochondral lesions are more often unstable, displaced, or symptomatic than medial lesions [12, 13].
  • AP, mortise, and lateral weight-bearing ankle x-rays may not demonstrate subtle osteochondral lesions [12, 13].
  • CT scan is helpful for determining the integrity of subchondral bone and identifying cysts in osteochondral lesions [12, 13].

Ankle Fractures and Syndesmosis

  • MRI lacks additional diagnostic value for stability assessment of the ankle mortise in supination-external rotation-type ankle fractures [16].
  • Preoperative computed tomography scans are used in operative planning for malleolar ankle fractures [16].
  • Malreduction of the posterior malleolus is significantly more likely to lead to malreduction of the syndesmosis [16].

Ligamentous and Soft Tissue Pathology

  • MRI is used for the evaluation of posterior tibial tendon dysfunction with relevance to clinical staging [1].
  • MRI is used for the evaluation of anterolateral soft tissue impingement of the ankle [1, 17].
  • MRI is used for the evaluation of osteochondral lesions of the talus [1].
  • MRI is used for the diagnosis of ligamentous and chondral pathology in the ankle [1].
  • MRI and stress radiography are used in the evaluation of chronic lateral ankle instability [1].
  • MRI is used for pre-operative evaluation of the anterior talofibular ligament in chronic ankle instability [1].
  • MRI findings are associated with symptoms in patients with chronic ankle sprain [1].
  • MRI is used for the imaging evaluation of traumatic ligamentous injuries of the ankle and foot [1].
  • MRI is used for the musculotendinous imaging of the ankle [1].
  • CT and MR imaging are used for the evaluation of the postoperative ankle and foot [1].
  • MRI is used for the diagnosis of plantar plate injury with reference to intraoperative findings [1].
  • MRI is compared to physical examination for the diagnosis of syndesmotic injury after lateral ankle sprain [2].
  • Peroneal tendon abnormalities are identified on routine magnetic resonance imaging of the foot and ankle [14].

Entrapment Neuropathies

  • MR imaging is used for the evaluation of entrapment neuropathies of the lower extremity, including the knee, leg, ankle, and foot [18].
  • Point-of-care ultrasonography is used in the diagnosis and management of superficial peroneal nerve entrapment [18].

References

[1] Campbell S Operative Orthopaedics 4 Volume Set. REFERENCES > FOOT AND ANKLE.

[2] Campbell S Operative Orthopaedics 4 Volume Set. REPAIR OF ACUTE RUPTURE OF LATERAL LIGAMENTS > ACUTE ANKLE LIGAMENT INJURIES, CHRONIC ANKLE INSTABILITY.

[3] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > BIOMECHANICS OF THE FOOT AND ANKLE.

[6] Campbell S Operative Orthopaedics 4 Volume Set. MULTIPLE Z-PLASTY RELEASE OF A CONGENITAL RING > ANKLE BLOCK.

[7] Apley And Solomon S Concise System Of Orthopaedics And Trauma. Treatment.

[8] Orthopaedic Knowledge Update Sports Medicine 6. Ankle and Foot Injuries and Other Disorders > Ankle Sprains > Medial Ankle Injury.

[11] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Foot and Ankle Anatomy and Biomechanics > Annotated References.

[12] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > OSTEOCHONDRAL LESIONS.

[13] Miller S Review Of Orthopaedics. OSTEOCHONDRAL LESIONS.

[14] Campbell S Operative Orthopaedics 4 Volume Set. MULTIPLE Z-PLASTY RELEASE OF A CONGENITAL RING > PERONEAL TENDONS.

[15] Orthopaedic Knowledge Update Sports Medicine 6. Ankle and Foot Injuries and Other Disorders > Summary.

[16] Orthopaedic Knowledge Update Trauma. Ankle Fractures > Annotated References.

[17] Campbell S Operative Orthopaedics 4 Volume Set. ARTHROSCOPIC EXAMINATION AND DEBRIDEMENT OF THE ANKLE JOINT > IMPINGEMENT.

[18] Campbell S Operative Orthopaedics 4 Volume Set. COMBINED HAMMER TOE AND MALLET TOE DEFORMITY WITH ASSOCIATED DOUBLE CORNS > REFERENCES > TARSAL TUNNEL SYNDROME.

Creative Commons BY-NC 4.0

CC Creative Commons licence
BY Attribution — you must credit the source
NC NonCommercial — not for commercial use

Attribution-NonCommercial 4.0 International

Creative Commons Corporation ("Creative Commons") is not a law firm and does not provide legal services or legal advice. Distribution of Creative Commons public licenses does not create a lawyer-client or other relationship. Creative Commons makes its licenses and related information available on an "as-is" basis. Creative Commons gives no warranties regarding its licenses, any material licensed under their terms and conditions, or any related information. Creative Commons disclaims all liability for damages resulting from their use to the fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and conditions that creators and other rights holders may use to share original works of authorship and other material subject to copyright and certain other rights specified in the public license below. The following considerations are for informational purposes only, are not exhaustive, and do not form part of our licenses.

Considerations for licensors: Our public licenses are intended for use by those authorized to give the public permission to use material in ways otherwise restricted by copyright and certain other rights. Our licenses are irrevocable. Licensors should read and understand the terms and conditions of the license they choose before applying it. Licensors should also secure all rights necessary before applying our licenses so that the public can reuse the material as expected. Licensors should clearly mark any material not subject to the license. This includes other CC- licensed material, or material used under an exception or limitation to copyright. More considerations for licensors: wiki.creativecommons.org/Considerations_for_licensors

Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees

Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

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.