WordNet

come into the company of; "She joined him for a drink"
cause to become joined or linked; "join these two parts so that they fit together" (同)bring together
make contact or come together; "The two roads join here" (同)conjoin
become part of; become a member of a group or organization; "He joined the Communist Party as a young man" (同)fall_in, get together
united or combined; "a joint session of Congress"; "joint owners"
marijuana leaves rolled into a cigarette for smoking (同)marijuana cigarette, reefer, stick, spliff
a disreputable place of entertainment
junction by which parts or objects are joined together
(anatomy) the point of connection between two bones or elements of a skeleton (especially if it allows motion) (同)articulation, articulatio
provide with a joint; "the carpenter jointed two pieces of wood" (同)articulate
affecting or involving two or more; "joint income-tax return"; "joint ownership"
fasten with a joint
fit as if by joints; "The boards fit neatly"
involving both houses of a legislature; "a joint session of Congress"
separate (meat) at the joint
the act of bringing two things into contact (especially for communication); "the joining of hands around the table"; "there was a connection via the internet" (同)connection, connexion
having joints or jointed segments;

PrepTutorEJDIC

〈二つ以上のもの〉‘を'『つなぐ』,結合する《+『名』+『together』(『up』)》;(…に)…‘を'つなぐ《+『名』+『to』(『onto』)+『名』》 / (線などで)〈二つ以上のもの〉‘の'間を結ぶ(つなぐ)《+『名』+『by』(『with』)+『名』》 / (友情・結婚などで)〈人〉‘を'結びつける《+『名』+『in』+『名』》 / 〈川・道などが〉…‘と'いっしょになる,合流する / 〈会など〉‘に'『加入する』 / (…で)〈人〉‘の'『仲間に入る』,‘と'いっしょになる《+『名』〈人〉+『in』(『for』)+『名』,+『名』〈人〉+『in』do『ing』》 / (…に)『加わる』《+『in』+『名』〈事〉/+『in』『with』+『名』〈人〉》 / (人と…を)『ともにする』《+『with』+『名』〈人〉+『in』+『名』(doing)》 / 〈川・道などが〉『いっしょになる』,合流する / 接合箇所(点,面,線);継ぎ目
『関節』 / 『継ぎ目』,接合箇所,合わせ目 / 継ぎ目と継ぎ目の間の部分,節 / (二つの部分を継いだり支えたりするのに用いる)継ぎ手,ジョイント / (枝や葉の)つけ根,節 / (骨付きの)肉の大切り身 / 《俗》安酒場,とばく宿,アヘン窟(くつ) / 『共同の』,共有の;連帯の,連合の / 両院合同の;二院制議会の両院の / …‘を'継ぎ合わせる;…‘を'継ぎ目(関節)でつなぐ / …‘を'継ぎ目で分ける;〈鳥・肉など〉‘を'関節で切り分ける
継ぎ目のある;関節のある

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/06/11 13:19:17」(JST)

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The acromioclavicular joint, or AC joint, is a joint at the top of the shoulder. It is the junction between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle.^[1] It is a plane synovial joint.

Structure

Ligaments

The joint is stabilized by three ligaments:

The acromioclavicular ligament, which attaches the clavicle to the acromion of the scapula.

Superior Acromioclavicular Ligament This ligament is a quadrilateral band, covering the superior part of the articulation, and extending between the upper part of the lateral end of the clavicle and the adjoining part of the upper surface of the acromion.

It is composed of parallel fibers, which interlace with the aponeuroses of the Trapezius and Deltoideus; below, it is in contact with the articular disk when this is present.

Inferior Acromioclavicular Ligament This ligament is somewhat thinner than the preceding; it covers the under part of the articulation, and is attached to the adjoining surfaces of the two bones.

It is in relation, above, in rare cases with the articular disk; below, with the tendon of the Supraspinatus

The coracoacromial ligament, which runs from the coracoid process to the acromion.

The Coracoacromial Ligament is a strong triangular band, extending between the coracoid process and the acromion.

It is attached, by its apex, to the summit of the acromion just in front of the articular surface for the clavicle; and by its broad base to the whole length of the lateral border of the coracoid process.

This ligament, together with the coracoid process and the acromion, forms a vault for the protection of the head of the humerus.

It is in relation, above, with the clavicle and under surface of the Deltoideus; below, with the tendon of the Supraspinatus, a bursa being interposed.

Its lateral border is continuous with a dense lamina that passes beneath the Deltoideus upon the tendons of the Supraspinatus and Infraspinatus.

The ligament is sometimes described as consisting of two marginal bands and a thinner intervening portion, the two bands being attached respectively to the apex and the base of the coracoid process, and joining together at the acromion.

When the Pectoralis minor is inserted, as occasionally is the case, into the capsule of the shoulder-joint instead of into the coracoid process, it passes between these two bands, and the intervening portion of the ligament is then deficient.

The coracoclavicular ligament, which consists of two ligaments, the conoid and the trapezoid ligaments.

The Coracoclavicular Ligament serves to connect the clavicle with the coracoid process of the scapula.

It does not properly belong to the acromioclavicular joint articulation, but is usually described with it, since it forms a most efficient means of retaining the clavicle in contact with the acromion. It consists of two fasciculi, called the trapezoid ligament and conoid ligament.

These ligaments are in relation, in front, with the Subclavius and Deltoideus; behind, with the Trapezius.

Variation

An X-ray study of 100 shoulders in US soldiers found considerable variation in the size and shape of the joint.^[2] The articular surfaces were notably different in size and form. On some they are separated by a meniscus attached to the superior acromioclavicular ligament. This meniscus may be a blade of fibrocartilage that extends nearly halfway into the joint or it may form a complete disc that divides the joint into two parts. In other joints no synovial joint is present with the joint being made by a pad of fibrous tissue attached to the outer end of the clavicle, and no articular cavity.^[2]

Function

The acromioclavicular joint allows the ability to raise the arm above the head. This joint functions as a pivot point (although technically it is a gliding synovial joint), acting like a strut to help with movement of the scapula resulting in a greater degree of arm rotation.

Clinical significance

Injury

A common injury to the AC joint is dislocation, often called AC separation or shoulder separation. This is not the same as a "shoulder dislocation," which refers to dislocation of the glenohumeral joint.

Acromioclavicular joint dislocation is particularly common in collision sports such as ice hockey, football, Judo, rugby and aussie rules, and is also a problem for those who participate in swimming, horseback riding, mountain biking, biking, snow skiing and skateboarding. The most common mechanism of injury is a fall on the tip of the shoulder or FOOSH (Fall On OutStretched Hand).

Acromioclavicular joint dislocations are graded from I to VI. Grading is based upon the degree of separation of the acromion from the clavicle with weight applied to the arm. Grade I is slight displacement of the joint, and a badly stretched or partially torn AC ligament. It has the normal separation of <4mm. Grade II is a partial dislocation of the AC joint with a complete disruption tear of the AC joint and a partial disruption of coracoclavicular ligament. The AC gap is >5mm. Grades I and II never require surgery and heal by themselves, though physical therapy may be required. Grade III is complete disruption of AC and CC ligaments. On plain film the inferior aspect of the clavicle will be above the superior aspect of the acromion. This can also be assessed with an MRI scan, which will also demonstrate disruption of the coracoclavicular ligaments (the degree depending on the severity of AC joint disruption) as well as tearing of the joint capsule. The joint will be very tender and swollen on examination. Grade III separations most often do not require surgery and shoulder function should return to normal after 16–20 weeks. However, there will be some physical deformity of the shoulder with a noticeable bump resulting from the dislocation of the clavicle. Grades IV-VI are complications on a 'standard' dislocation involving a displacement of the clavicle, and will almost always require surgery. Dynamic US is critical to detect mild (grade I) dislocations, especially because they may present as a normal joint in static images. Doppler US may also be used to increase diagnostic confidence to detect low-grade injuries because it depicts reparative process to injured ligament.^[3]

Osteoarthritis

Osteoarthritis of the acromioclavicular joint is not uncommon. It may be caused by a prior trauma (secondary osteoarthritis) or occur as a chronic degenerative disorder. In the latter cases the condition often co-exist with subacromial impingement.

Additional images

Diagram of the human shoulder joint

References

^ SimonMoyes.co.uk. "What is Acromioclavicular Joint Osteoarthritis?".
^ ^a ^b URIST, M. R. (1946). COMPLETE DISLOCATIONS OF THE ACROMIOCLAVICULAR JOINT: The Nature of the Traumatic Lesion and Effective Methods of Treatment with an Analysis of Forty-One Cases. J. Bone Joint Surg. Am.28: 813 - 837.
^ Arend CF. Ultrasound of the Shoulder. Master Medical Books, 2013

External links

Images from an MRI scan demonstrating AC Joint Injury - Grade II sprain
What is Acromioclavicular Joint Osteoarthritis? - www.SimonMoyes.co.uk
Acromioclavicular joint disease

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 肩鎖関節損傷 acromioclavicular joint injuries
2. 肩鎖関節障害 acromioclavicular joint disorders
3. 肩部の身体診察 physical examination of the shoulder
4. 小児および思春期における急性肩痛および傷害の外傷性原因 traumatic causes of acute shoulder pain and injury in children and adolescents
5. 患者情報：肩鎖関節損傷（肩鎖関節の離開）（詳細） acromioclavicular joint injury shoulder separation beyond the basics

English Journal

Biomechanical loading of the shoulder complex and lumbosacral joints during dynamic cart pushing task.

Nimbarte AD, Sun Y, Jaridi M, Hsiao H.SourceDepartment of Industrial and Management Systems Engineering, PO Box 6070, West Virginia University, Morgantown, WV 26506-6107, USA. Ashish.Nimbarte@mail.wvu.edu
Applied ergonomics.Appl Ergon.2013 Sep;44(5):841-9. doi: 10.1016/j.apergo.2013.02.008. Epub 2013 Apr 5.
The primary objective of this study was to quantify the effect of dynamic cart pushing exertions on the biomechanical loading of shoulder and low back. Ten participants performed cart pushing tasks on flat (0°), 5°, and 10° ramped walkways at 20 kg, 30 kg, and 40 kg weight conditions. An optoelec
PMID 23566675

The prevalence of chondrocalcinosis (CC) of the acromioclavicular (AC) joint on chest radiographs and correlation with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease.

Parperis K, Carrera G, Baynes K, Mautz A, Dubois M, Cerniglia R, Ryan LM.SourceDivision of Rheumatology, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI, 53226, USA, kparperis@mcw.edu.
Clinical rheumatology.Clin Rheumatol.2013 Sep;32(9):1383-6. doi: 10.1007/s10067-013-2255-x. Epub 2013 Apr 23.
Digital imaging combined with picture archiving and communication system (PACS) access allows detailed image retrieval and magnification. Calcium pyrophosphate dihydrate (CPPD) crystals preferentially deposit in fibrocartilages, the cartilage of the acromioclavicular (AC) joint being one such struct
PMID 23609408

What Role Do Plain Radiographs Have in Assessing the Skeletally Immature Acromioclavicular Joint?

Lee SY, Kwon SS, Chung CY, Lee KM, Park MS.SourceDepartment of Orthopaedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-Dong, Bundang-Gu, Sungnam, Kyungki, 463-707, Korea.
Clinical orthopaedics and related research.Clin Orthop Relat Res.2013 Aug 20. [Epub ahead of print]
BACKGROUND: Because of incomplete ossification of the coracoid process and acromion, acromioclavicular joint configuration in the skeletally immature patient differs from that of adults. Although comparison to radiographic standards for this joint is critical in the evaluation of acromioclavicular j
PMID 23959906

Japanese Journal

肩鎖関節脱臼の治療・第1報 : 保存療法に対する超音波検査が有用であった一例

増田雅保,森加奈子,増田博之
日本柔道整復接骨医学会誌 = Journal of judo therapy 20(2), 83-88, 2012-05-15
NAID 10030648212

肩鎖関節脱臼に対する術後成績の検討

福井友章,渡辺裕介,堀芳郎,青木謙二,高山博行,原田俊彦
中部日本整形外科災害外科学会雑誌. 中部日本整形外科災害外科学会抄録 55(2), 339-340, 2012-03-01
NAID 10030521202

Related Pictures

★リンクテーブル★

リンク元	「肩鎖関節」
関連記事	「join」「joint」

「肩鎖関節」

Acromio-clavicular joint
	The left shoulder and acromioclavicular joint
	Glenoid cavity of the right scapula
Details
Latin	Articulatio acromioclavicularis
Identifiers
Gray's	p.315
MeSH	A02.835.583.032
Dorlands; /Elsevier	a_64/12160945
TA	A03.5.03.001
FMA	25898
	Anatomical terminology