Navicular bone type

Accessory navicular boneThree distinct types of accessorynavicular bones have beendescribed (Fig. 1): (1) a small, roundseparate ossicle imbedded withinthe posterior tibial tendon

(type 1);(2) a larger, triangular Ossification centre adjacent to the navicular tuberosity and connected by a Synchondrosis (type 2); and (3) An enlarged medial horn of the Navicular itself, called a cornuate navicular(type 3). These three types have acollective incidence of 4 to

21% (3).

• Shoulder impingement SD– 임상적 진단 , Tendinosis 에서 rotator

cuff tear 까지 다양한 MR finding 의 특징을 보임 .

– Intrinsic; shoulder instability Extrinsic; acromion 의 inferior sur-

face 에 의해 rotator cuff 의 abrasion이 나타남 .

– Pathogenesis• Impingement; rotator cuff 의 tendinous

fiber 가 greator tuberosity 에 부착하는 부위에 degenerative change 가 일어나면서 발생함 , SST 가 부착하는 부위에 m.c

• Bursa inflammation and tendinitis caused by compression

• Hooked type 3 acromion and muscle weakness

• Chronic compressiv and irritative force-> CA lig. 에 변화 -> anterior spur-> fur-ther impingement

-> m/c location of impingement SD ;anterior 1/3 of acromion and underly-

ing tendon

– X-ray; anterior tilr /low posiotion of acromion

• Radial head fracture– Classification

• Mason type1; undisplaced frx.• Mason type2; marginal fracture with

displacement angulation, depression, impaction• Mason type3; comminuted frx,

– Complication• Essex-Lopresti injury; comminuted and

dispaced radial head frx, disruption of distal radioulnar jt.

-> longitudinal force applied to out-stretched hand that lead to impaction of radial head and capitulum

-> immediate prox. migration of radial shaft related to severity of radial head fracture

->interosseous mb disrupted,

Ligaments of Humphrey & Wrisberg

Discussion:     - the ligaments of Humphrey and Wrisberg are meniscofemoral ligaments which run from the posterior horn of the          lateral meniscus to the lateral aspect of the medial femoral condyle;    - these ligaments are named based on their location in relation to the PCL;          - the anterior meniscofemoral ligament is known as the ligament of Humphrey where as the posterior meniscofemoral                 ligament is known as the ligament of Wrisberg;    - in about 70 % of knees, there is either anterior meniscofemoral ligament of Humphrey or posterior          meniscofemoral ligament of Wrisberg;          - latter is more common and is characterized by femoral origin merging w/ that of posterior cruciate ligament;          - in 6% of knees, both ligaments will be present;    - these meniscofemoral ligaments may play minor role as secondary restraints to poste-rior tibial translation after complete          transection of the posterior cruciate ligament;    - Humphrey ligament: (anterior meniscofemoral ligament);          - is less than 1/3 the diameter of the PCL;          - arises from the posterior horn of the lateral meniscus, runs anterior to the to the PCL and inserts at the                 distal edge of the femoral PCL attachment;          - may be confused for the PCL during arthroscopy;                 - in this situation, tug on the ligament while observing for motion of the lateral meniscus;    - Wrisberg's ligament: (posterior meniscofemoral ligament);          - usually larger than ligament of Humphrey (upto 1/2 the diameter of the PCL diame-ter);          - extends from the posterior horn of lateral meniscus to medial femoral condyle;

• 황후주 052Y/M 10197197 2008-12-12

• [Reading]• Distal L5 spine level에서 central canal에서 주변의 muscular struc-

ture로 extension을 보이는 molded loculated 양상의 lesion이 관찰되며 , T2WI에서 high signal intensity를 보이고 T1WI에서 low signal intensity를 보여 cystic lesion으로 보임 . 이 lesion은 mass ef-fect를 보이며 thecal sac을 left side로 compression하고 있음 .

• Lumbar spine에 small marginal osteophyte들이 있음 .• L5에 bilateral total laminectomy state임 .• L4-5에 central to right aspect에서 right extraforaminal aspect

까지 asymmetric diffuse disc bulging을 보이고 있음 .• L5-S1에 central to right disc extrusion이 있음 .• Scan이 cover된 level에 neural foraminal canal narrowing evi-

dence 보이지 않음 .• 그 외 soft tissue에 다른 abnormality 보이지 않음 .

• --------------------------------• [Conclusion]• 1. Hematoma in central canal to adjacent muscular structure

around distal L5 level, most likely.• DDx.Loculated CSF. • 2. Lumbar spondylosis.• 3. S/P Bilateral total laminectomy at L5-S1.• 4. Asymmetric diffuse disc bulging at L4-5.• 5. Central to right disc extrusion at L5-S1.• 6. No evidence of central canal narrowing or neural foraminal

canal narrowing.

• MR arthrography• TechniqueThe T1-weighted signal intensity of contrast material depends on the concentration of gadolinium and the magnetic field strength. To optimize theparamagnetic effect of gadolinium at 1.5 T, pharmaceutic preparations should bediluted to a concentration of 2 mmol/L (9). There are numerous ways to obtain this concentration, depending onwhether iodinated contrast material is mixed with the gadolinium. If iodinated contrast material is used, 0.8 mL of gadopentetate dimeglumine orsome other form of gadolinium can be added to 100 mL of normal saline solution. Ten mL of this solution can then be mixed with 5 mL of iodinatedcontrast material and 5 mL of lidocaine 1% (final gadolinium dilution ratio 1:250). Following aspiration of any joint fluid, this mixture isinjected until the joint capsule is properly distended (approximately 12 mL in the shoulder). Single-contrast technique is necessary to avoidmagnetic susceptibility artifact from intraarticular gas. The use of iodinated contrast material allows fluoroscopic confirmation of intraarticular needleplacement and acquisition of standard pre- and Post image• MR ARTHROGRAPHY TECHNIQUE AND CLINICAL INDICATIONS Bolog N1, Mangrau Angelica1, Oancea Irinel 1, Banicescu Antonia 1, Andreisek G2

1 Phoenix Diagnostic Clinic, Bucharest, Romania, 2 University Hospital Zurich, Switzerland

• Direct magnetic resonance (MR) arthrography consists of direct injection of di-luted gadolinium in the joints. The technique is used mostly for evaluating certain pathologic conditions of the shoulder and hip. During the MR arthrog-raphy of the shoulder, the joint is in a neutral position and is punctured with a 21-gauge spinal needle under fluoroscopic guidance. Approximately 1-2 mL of contrast medium is injected under fluoroscopic guidance for confirmation of the intraarticular location of the needle tip and is followed by slow injection of 15-20 mL of diluted MR contrast medium. MR arthroagraphy of the shoulder is indicated in patients with suspected labral tears, shoulder instability, loose bodies. Practically, at this moment more than 90% of the shoulder MR exami-nations in clinical practice are performed with this technique. For MR arthrog-raphy of the hip a direct anterior or anterolateral approach to the hip is used. A small amount of iodinated contrast material is injected to document intraar-ticular needle position. Once the intraarticular position is fluoroscopically con-firmed, 8-15 mL of dilute solution of gadopentetate dimeglumine is injected. MR arthrography may depict intraarticular loose bodies, osteochondral ab-normalities, and abnormalities of the supporting soft-tissue structures.

• Oreo cookie sign• Schematic representations in

coronal plane of single and double "Oreo cookie" configu-rations.

Single Oreo cookie configura-tion is characterized by fluid between labrum and glenoid cartilage. This finding could be observed with either sublabral recess (arrow) or type II supe-rior labral anteroposterior le-sion.

• Schematic representations in coronal plane of single and double "Oreo cookie" configu-rations. Double Oreo cookie configuration is characterized by fluid between labrum and glenoid cartilage and between two pieces of labrum. Arrow indicates sublabral recess and arrowhead indicates labral tear.

AJR

• The polka-dot sign is seen on trans-verse computed tomographic (CT) im-ages of vertebral bodies. The medullary cavity of the vertebral body shows numerous high attenuation dots (Figure), simulating the polka-dot pat-tern on clothing.

• Transverse CT image of a lumbar ver-tebra demonstrates typical polka-dot appearance of a vertebral heman-gioma involving most of the medullary cavity.

• Discoid Meniscus•

- Dicussion:    - a thickened and wafer shaped lateral meniscus varient;    - discoid meniscus may range from complete disc to a ring shaped meniscus;    - occurs in upto 5% of population (but only a % of these are symptomatic) (prevalence may be higher in orientals (15%));    - usually involves lateral meniscus and is frequently bilateral (20% of pts);    - although a congenital etiology for discoid menisci has been proposed, the discoid variant is not normally  found in the fetus;    - clinically patients may complain of pain, swelling, and snapping;          - the classic discoid snapping knee is usually caused by a discoid meniscus w/ a deficient menisco-tibial ligament;    - classification:             - based on the degree of peripheral attachments to the tibia plateau;             - complete vs. incomplete                    - the terms complete and incomplete are sometimes used to describe the shape of the discoid meniscus (incomplete having a more semilunar shape);                    - the same terms (complete and incomplete have also been used to describe whether the meniscus is stable vs unstable;             - stable                    - complete type has normal peripheral attachments & normal mobility.                    - these meniscal varients tend to be stable due to the presence of a posterior menisco-femoral ligament;                    - when symptomatic, either a tear or a posterior menisco-femoral detachment is usu-aly present;                    - treatment: arthroscopic partial menisectomy and meniscoplasty             - unstable (wrisberg)                    - these are unstable and hypermobile to due lack of posterior tibio-meniscal liga-ments;                    - has only one attachment posperiorly, posterior meniscofemoral ligament,                    - on knee extension, abnormal meniscus is pulled posteromedially into the intercondy-lar notch (instead of gliding forward) due to the action of the meniscofemoral ligaments;                           - probably responsible for the true "snapping knee;"                    - total menisectomy is recommended for Wrisberg type deformity since lacks posterior meniscal tibial attachments & has unstable posterior horn;             - varients:                    - anterior or posterior megahorn;

- Radiographs:    - x-rays:             - lateral joint space widening and cupping of lateral tibial plateau;             - hypoplasia of the lateral tibial spine;    - MRI:             - suggestive finding include meniscal tissue on 3 or more contiguous saggital cuts;             - note: a classic false negative can occur w/ an unstable (Wrisberg) type of discoid menis-cus which maintains a relative semilunar shape;

- Non Operative Treatment:    - an asymptomapic discoid meniscus does not require treatment and prognosis is generally good;    - symptoms of popping by itself is not harmful unless it is accompanied by pain or swelling of the knee;

- Operative Treatment:    - all forms of operative treatment are controversial;    - pain, swelling, & a history of trauma are relative indications for arthroscopy;    - tears of a stable meniscus may require resection of the discoid lateral meniscus, leaving pe-ripheral rim intact (meniscoplasty);          - rescetion is often difficult because of increased meniscal thickness    - w/ a unstable discoid meniscus, a complete menisectomy is required;

Discoid MeniscusBy Jonathan Cluett, M.D., About.comAbout.com Health's Disease and Condition content is

reviewed by the Medical Review Board

Definition: A discoid meniscus is an abnormally shaped meniscus within the knee joint. The meniscus is a C-shaped wedge of cartilage that helps support and cushion the knee joint. In each knee there are two menisci, one on the inside (me-dial) and one on the outside (lateral) of the knee joint. In some people the lateral meniscus is shaped more like a solid disc rather than the normal C-shape. Most people with a discoid meniscus never know they have it! Many people live normal, active lives with a discoid meniscus--even high perfor-mance athletes. Therefore, if your doctor finds that you have a discoid meniscus, but it is not the cause of your symptoms, it would be left alone.

In some people, the discoid meniscus can cause prob-lems, usually a popping sensation with pain over the outside part of the knee joint. This is why some people use the phrase 'popping knee syndrome' when talking about a discoid meniscus. In these pa-tients, conservative treatment consisting of exer-cises and stretching can be performed. If these treatments do not relieve the symptoms, patients may choose arthroscopic surgery on the discoid meniscus. If the discoid meniscus is torn, the torn portion can be removed. In addition, the discoid meniscus can be shaved into a more normal appear-ing meniscus.

• Disc protrusion/ extrusion• Definition: Several words are used to describe

the extent of a disc herniation seen on MRI ex-amination. A disc herniation occurs when the soft cushion between the spinal bone ruptures. A portion of that disc can herniate, or push out-wards, against the spinal cord or the spinal nerves. The pressure on the nerves causes the symptoms typical of a disc herniation. The types of disc herniation that occur include:

• Disc ProtrusionCommonly called a disc bulge, a disc protrusion occurs with the spinal disc and the associated ligaments remain in tact, but form an outpouch-ing that can press against the nerves.

• Disc ExtrusionA disc extrusion occurs when the outer part of the spinal disc ruptures, allowing the inner, gelatinous part of the disc to squeeze out. Disc extrusions can occur with the ligaments in tact, or damaged.

• Disc SequestrationA disc sequestration occurs when the center, gelatinous portion of the disc is not only squeezed out, but also separated from the main part of the disc.

Disc Extrusion, Protrusion, and SequestrationBy Jonathan Cluett, M.D., About.comAbout.com Health's Disease and Condition content

is reviewed by the Medical Review Board

• Tarsal Tunnel Syndrome• Posted July 22nd, 2002 by Matt in Foot • A Patient's Guide to Tarsal Tunnel Syndrome• Introduction• Tarsal tunnel syndrome is a condition that occurs from abnormal

pressure on a nerve in the foot. The condition is similar to carpal tunnel syndrome in the wrist. The condition is somewhat uncom-mon and can be difficult to diagnose.

• This guide will help you understand• where the tarsal tunnel is located • how tarsal tunnel syndrome develops • what can be done to treat the condition • Anatomy• Where is the tarsal tunnel, and what does it do?• The tibial nerve runs into the foot behind the medial malleolus, the

bump on the inside of the ankle. As it enters the foot, the nerve runs under a band of fibrous tissue called the flexor retinaculum. The flexor retinaculum is a dense band of fibrous tissue that forms a sort of tunnel, or tube. Several tendons, as well as the nerve, artery, and veins that travel to the bottom of the foot pass through this tunnel. This tunnel is called the tarsal tunnel. The tarsal tunnel is made up of the bone of the ankle on one side and the thick band of the flexor retinaculum on the other side.

• Causes• In many cases, doctors aren't sure what causes tarsal tunnel syn-

drome. Inflammation in the tissues around the tibial nerve may contribute to the problem by causing swelling in the tissues and pressure on the nerve.

• Anything that takes up space in the tarsal tunnel can increase pressure in the area because the flexor retinaculum cannot stretch very much. This can occur from swollen varicose veins, a tumor (noncancerous) on the tibial nerve, and swelling caused by other conditions, such as diabetes. As pressure increases in the tarsal tunnel, the nerve is the most sensitive to the pressure and is squeezed against the flexor retinaculum. This causes problems in the nerve that may lead to symptoms of tarsal tunnel syndrome.

• In the case of a nerve, the area of skin supplied by the nerve usu-ally feels numb, and the muscles controlled by the nerve may be-come weak. Pain is sometimes felt near the area where the nerve is squeezed or pinched.

• Femoral anteversion and an-tetorsion

• Both anteversion and antetorsion are trans-verse plane measures (Hertling & Kessler, 1996, pp.286-287)

• Anteversion is an angular measurement that re-lates the femoral neck's position or posture to the frontal plane. The figure (Wheeless, 1996) illus-trates anteversion angle

The long axis of the femur is the line defined by two points: the center of the knee(the centroid of the distal femoral metaphysis on a cross section through the femoral condyles)K, and the center of the base of the femoral neck (the centroid of the femoral diaphysis on a cross section through the base of the femoral neck), 0 (Fig. 1 ). The axis of the femoral neck is the line defined by two points: the center of the femoral head, H, and the center of the base of the femoral neck, The plane of anteversion is the plane that containsboth the long axis of the femur and the axis of the femoral neck. The condylar axis is the line that is parallel to theposterior aspects of the femoral condyles and passes through the center of the knee, K. The condylar plane contains boththe long axis of the femur and the condylar axis. The angle of anteversion is the angle in the transverse plane between the plane of anteversion and the condylar plane.

• Meniscal flounce• Definition:Uncommon normal

variant of meniscus character-ized by redundancy or fold oc-curring along free edge of meniscus

• Bowtie app. Normal meniscus: bowtie ap-

pearance on peripheral sagittal slices

Figure 6 Meniscal flounce. Sagittal FSE PD (TR/TE 2200/15) image through the knee. There is redundancy in the posterior horn of the me-dial meniscus, consistent with a meniscal flounce

• Normal development• Femoral anteversion decreases from approximately 40° at birth to approximately 15°

at maturity. Lateral rotation of the tibia increases from approximately 5° at birth to ap-proximately 15° at maturity.

• Tibial torsion• Medial torsion improves with time. Lateral torsion often worsens because the natural

progression is toward increasing external torsion. The ability to compensate for tibial torsion depends on the amount of inversion and eversion present in the foot and on the amount of rotation possible at the hip. Internal torsion causes the foot to adduct, and the patient tries to compensate by everting the foot and/or by externally rotating at the hip. Similarly, persons with external tibial torsion invert at the foot and internally rotate at the hip.

• Femoral anteversion• Normal femoral anteversion is 40° in the newborn and decreases to 10-15° by the age

of 8 years. The acetabulum is angled forward 15°. Femoral anteversion does not in-crease the risk of arthritis of the hip. Spontaneous improvement in the anatomic posi-tion can occur until the patient is aged 8 years and by improving the gait through con-scious effort until adolescence.

• Examination• The diagnosis is based on clinical findings, and other investigations generally are not

required. Examination must include tests to exclude hip dysplasia, hip and ankle ranges of motion, and knee varus or valgus, which can cause apparent errors in exam-ination. In some cases, imaging studies may be helpful (see Imaging Studies). How-ever, not every child who undergoes an evaluation because of torsional issues requires any or all of these imaging tests.

• A rotational profile consists of the following:Foot progression angle (FPA)

• Tibial version or torsion – Thigh foot axis (TFA) www.emedicine.com/orthoped/

TOPIC450– Transmalleolar angle

• Femoral anteversion (hip rotation) • Shape of the foot• The FPA is the angular difference between the axis of the foot and the line of progres-

sion. Normal FPA is 10-15° of external rotation. By convention, external rotation values are positive, and internal rotation values are negative. Degrees of intoeing are as fol-lows:Mild is -5 to -10°.

• Moderate is -10 to -15°. • Severe is more than -15°.• Tibial version or torsion is the degree of rotation of the tibia along its long axis from the

knee to the ankle. It is measured with the patient prone with his or her knees flexed to 90°. It is assessed by using the following 2 measures:Thigh foot axis: This is measured with the patient prone and the knees flexed to 90°, with the examiner looking at the feet from above. It is the angle between the line of axis of the thigh and the line along axis of foot. A normal TFA is 10-15° of external rota-tion. By convention, external rotation values are positive, and internal rotation values are negative.

• The transmalleolar axis is the axis of the line joining the 2 malleoli. Because the lateral malleolus is normally posterior to the medial malleolus, the transmalleolar axis is ex-ternally rotated by 15-20°, as measured with reference to the coronal plane axis. A transmalleolar axis rotated externally greater than 20° signifies external tibial torsion, and a transmalleolar axis rotated externally less than 10° signifies internal tibial tor-sion.

• Femoral anteversion is the axial angle between the plane of the neck of the femur and the femoral condyles. It can be clinically deduced by measuring the hip rotation. Nor-mal range of external rotation is 45-70°, and internal rotation is 10-45°. As femoral an-teversion increases, the amount of internal rotation increases and external rotation de-creases. These children can have as much as 90° of internal rotation and 0° of external rotation. They sit in the W position with their legs turned out (a position not attainable by normal adults), but they cannot sit cross-legged.

• The shape of the foot is best assessed with the patient standing and examined from the back, or the patient is prone and the feet are assessed by looking at the soles of the feet. Metatarsus adductus (or uncommonly, abductus) can be seen.

• Enthesophyte• a bone excrescence at the site of tendon or

ligament attachment to bone. Common sites of enthesophyte formation are given in Table 1. Hyperostosis is frequent in older patients and may occur in degenerative diseases or in diffuse idiopathic skeletal hyperostosis DISH . Such excrescences may involve the ischial tuberosity, trochanters, calcaneus, ulnar ole-cranon and patella. The bone outgrowth may also be called a spur.

• Table 1. Common sites of enthesophytes. – Calcaneus – Ulnar olecranon – Patella – Acromion – Innominate bone

Lateral radiograph of the heel demonstrates ossifica-tion in the Achilles tendon and plantar fascia at the posterior and plantar as-pect of the calcaneus, re-spectively.

• Diffuse Idiopathic Skeletal Hyperostosis• General Considerations

– More common in Caucasian males aged 50-75 years – Ossification of anterior longitudinal ligament with or without osteophytes is the primary pathol-

ogy – DISH is an enthesopathy – there is reaction at the sites of tendinous insertions (entheses) – Laminated, flowing ossification – Should involve four contiguous vertebral bodies – Ossification is usually quite thick – Disc height is maintained in affected area – Does not have ankylosis of SI joints

• Involvement of SI joints excludes DISH

– Involves lower thoracic spine most often, but also cervical and lower lumbar spine most fre-quently

• Left side of spine in thoracic area tends to not have ossification because of pulsations of aorta

• Clinical Findings – Back stiffness or, less frequently, back pain

• Stiffness is worse in the morning

– Large osteophytes have also been reported to compress or obstruct a number of structures, in-cluding:

• Bronchus • IVC • Esophagus • Increased incidence of calcification in surgical scars • Associated with

– Hyperostosis frontalis interna – Ossification of the posterior longitudinal ligament (OPLL) – Ossification of the vertebral arch ligaments (OVAL)

• Imaging Findings – Conventional radiography is usually study of choice – Flowing ossification along anterior aspect of vertebral bodies, but separated from them and the

body – Should involve 4 levels – Ossification may thicken as disease becomes more chronic – “Whiskering” at the sites of tendinous insertion (entheses)

• Pelvic involvement – Iliac crests – Ischial tuberosities – Iliolumbar ligaments – Lesser trochanter

• Deltoid tuberosities of humerus • Olecranon spurs

– Also may have ossification of the • Achilles tendon • Plantar aponeurosis • Triceps tendon

• DDX: – Ankylosing spondylitis

• Has involvement of SI joints • Syndesmophytes are thinner

– Degenerative disc disease • Osteophytes form only at corners of vertebral bodies • Narrowing and desiccation of disc

– Acromegaly • May produce osteophytes but they are not flowing

– Fluorosis may produce osteophytes, whiskering and ligamentous ossification • But all bones are uniformly increased in density

• From Learinig radiology.com

• Types of SLAP Tears• Lennard Funk

If you have been diagnosed with a SLAP tear, your surgeon may have called it a 'Type 1 or 2 or 3, etc'. SLAP tears have been classified according to their severity of tear. Please note that it does not mean that the outcome of surgery is worse, it just gives us surgeons a guide to management and a form of communication. The common types are types 1 to 4. There are other types, but these are rare.

• SLAP Type 1• This is a partial tear of the labrum, where the edges are rough but not completely

detached. • Treatment is usually to 'debride' (clean) the edges. • SLAP Type 2• Type 2 is the comonest type of SLAP tear. The labrum is completely torn off the

bone, due to an injury (often a shoulder dislocation).• Treatment is reattachment of the labrum (SLAP repair). This is done

arthroscopically (keyhole) using suture anchors.• SLAP Type 3• A Type 3 tear is a 'bucket-handle' tear of the labrum, where the torn labrum hangs

into the joint and causes symptoms of 'locking' and 'popping' or 'clunking'.• Treatment usually involves removal of the 'bucket-handle' segment and then re-

pair of any remaining detached, unstable labrum (SLAP repair). This is done arthroscopically (keyhole) using suture anchors.

•  • SLAP Type 4• The Type 4 SLAP tear is one where the tear of the labrum extends into the long

head of biceps tendon.• Treatment is reattachment of the labrum (SLAP repair) and repair of the biceps

tear, or a biceps tenodesis. This is done arthroscopically (keyhole) using suture anchors.

• For more information, please see the Education Section

Shoulderdoc.co.uk

• Ossification of the posterior lon-gitudinal ligament – OPLL

The ligament between the vertebrae and the spinal dura is called the posterior longitudinal ligament. Ossi-fication – or bone formation - in the ligament can com-press the spinal cord. The existence of OPLL requires special planning for surg-eries done from the front of the cervical spine.

Oxford university on line

From Wikipedia, the free encyclopedia

• Hand extensor compartment• The extensors are located on the back of

the forearm and are connected in a more complex way than the flexors to the dor-sum of the fingers. The tendons unite with the interosseous and lumbrical muscles to form the extensorhood mechanism. The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm; the tendons of these form the anatomical snuff box. Also, the index finger and the little finger have an extra extensor, used for instance for pointing.

• The extensors are situated within 6 sepa-rate compartments. The 1st compartment contains abductor pollicis longus and ex-tensor pollicis brevis. The 2nd compart-ment contains extensors carpi radialis longus and brevis. The 3rd compartment contains extensor pollicis longus. The ex-tensor digitorum indicis and extensor digi-titorum communis are within the 4th com-partment. Extensor digiti minimi is in the fifth, and extensor carpi ulnaris is in the 6th.

• TFCC• Anatomy of TFCC:

    - consists of articular disc (triangulyar fibrocartilage), meniscus homo-logue (lunocarpal), ulnocarpal ligament, dorsal & volar radioulnar liga-ment, and ECU sheath;    - it originates from firm attachments on medial border of distal radius and inserts into the base of the ulnar styloid;    - it separates the radiocarpal from the distal radioulnar joint;    - thickness of TFCC is roughly 5 mm at ulnar side and 2 mm thick at ra-dial side;    - vascular anatomy: only the peripheral 15-20% of the TFCC has a blood supply;    - ligamentous attachements: (see ligament of the wrist)           - ulnar attachment of the TFCC is anchored by two bands inserting to the styloid process and fovea (base of the styloid);           - volar ulnocarpal ligaments run from the base of the ulnar styloid process across the volar surface of the TFCC, and then insert on the lunate and triquetrum;           - ulnocarpal ligaments include:                   - volar ulnolunate:                   - ulnotriquetral ligaments:           - these ligaments prevent dorsal migration of the distal ulna;           - because the ulnar styloid moves away from the carpi in supina-tion, these ligaments are more taught in supination;    - blood supply:           - central disk is avascular;           - peripheral vessels penetrate approximately 10-40% of the TFCC margins;

- Function:    - TFCC is main stabilizer of distal radioulnar joint, in addition to con-tributing to ulnocarpal stability;           - its important in loading & stabilizing of distal radioulnar joint;           - TFCC normally not only stabilizes the ulnar head in sigmoid notch of radius but also acts as a buttress to support proximal carpal row;    - during axial loading, the radius carries the majority of load (82%), and the ulna a smaller load (18%);           - increasing the ulnar variance to a positive 2.5 mm increases the load transmission across the TFCC to 42%;           - w/ the TFCC excised, the radial load increases to 94%;    - stabilizing role: (see DRUJ instability)           - volar TFC prevents dorsal displacement of ulna and is tight in pronation;           - dorsal TFC prevents volar displacement of ulna and is tight in supination;

Wheeless' Textbook of Or-thopaedics

24

a Bankart lesion

b bony Bankart lesion

c Perthes lesion

d ALPSA lesion

e GLAD lesion

f HAGL lesion.

Eur Radiol. 2006 Dec;16(12):2622-36.

Bankart and Vari-ants

25

Current SLAP Lesion Classifica-tion with Associated

Clinical Findings and Mecha-nisms of Injury

 I Fraying Could be incidental finding; more significant in young people involved in overhead activities   

 II Tear with biceps extension Most common type; association with acute traction, repetitive overhead motion, and microinstability; could be associated with type IV   

 III Bucket-handle tear with intact biceps Less se-vere than type IV; association with fall on out-stretched arm    

IV Bucket-handle tear with biceps extension More severe than type III because of biceps extension; could be associated with type II; association with fall on outstretched arm.   

V Not specified Either a Bankart lesion with superior extension or a SLAP lesion with anterior inferior ex-tension    

VI Anterior or posterior flap tear Probably repre-sents type IV or less likely type III with tear of the bucket-handle component    

VII Not specified Type of middle glenohumeral liga-ment extension (avulsion or split) not specified; association with acute trauma with anterior disloca-tion   

VIII Not specified Similar to type IIB but with more ex-tensive abnormalities; association with acute trauma with posterior dislocation   

IX Not specified Global labrum abnormality; proba-bly traumatic event  

X Not specified +Rotator interval extension; articu-lar side abnormalities   

26

I FrayingII TearIII Bucket

handle tearIV Biceps ten-

don

V Bankart Fray-ing

VI FlapVII MGHLVIII PosteriorIX AnteriorPos-

teriorX RCI

SLAP lesion

27

SLAP lesion

Cisterna chyliFrom Wikipedia, the free encyclopediaThe cisterna chyli (or Cysterna chyli, receptaculum chyli) is a dilated sac at the lower end of the thoracic duct into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow.

[edit] Flow of lymphIt forms the primary lymph vessel transporting lymph and chyle from the abdomen to the left subclavian vein. It occurs inconsistently and when present is located posterior to the aorta on the anterior aspect of the bodies of the first and sec-ond lumbar vertebrae. The cisterna chyli receives fatty chyle from the intestines and thus acts as a conduit for the lipid products of digestion.

[edit] Additional imagesScheme showing relative positions of primary lymph sacs.Deep lymph nodes and vessels of the thorax and abdomen (diagrammatic).The relations of the viscera and large vessels of the abdomen.Lymphatic system

• Discussion:     - a common congenital fragmentation or synchondrosis of the patella

    - occurs in approximately 1% of population but some have observed a much higher incidence;     - most remain asymptomatic, but direct trauma may disrupt the synchondroses, causing symtoms that mimic those of fracture;     - classification:           - type I: inferior pole of the patella;           - type II: lateral margin type;           - type III: superolateral type;     - diff dx:           - stress frx: look for verticle fracture line;           - Sindig-Larsen-Johanssen disease may resemble a type I bipar-tite patella;           - patellar sleeve fracture           - osteochondral frx:                  - is distinguished from biparte patella:                        - on basis of history of trauma;                        - hemarthrosis of knee;                        - point tenderness over defect                        - distinct outline of frx on radiographs;                        - unilateral defect (less than 45% of patients will have bi-lateral bipartite patella);                        - rapid resolution of symptoms w/ fracture (w/ immobi-lization);

- Treatment:     - type I patella:           - patient with type I bipartite frx (lower pole) may at risk for frac-ture;           - patients that present with pain and tenderness at the lower pole, should have all activites curtailed;           - fractures occur along the synchondrosis and when displaced, operative fixation is considered;     - type III patella:           - superolateral bipartite patellae may become symptomatic and in some cases may require excision;           - also consider limited detachment of vastus lateralis from the bipartite fragment which removes the stress on the fragment and which can allow spontaneous union;

• Unhappy triad: (or terrible triad, or O'Donoghue's triad[1]) is an injury to the knee. It commonly occurs in contact sports (such as American football). The mecha-nism for this injury occurs when a lateral (outside) force to the knee is received while the foot is fixed on the ground in external rotation.

• Structures in triad• This scenario causes an injury to three knee structures:• the anterior cruciate ligament • the medial collateral ligament (or "tibial collateral liga-

ment") • the medial meniscus • The inclusion of the lateral meniscus in the triad has been

recently ascertained as it previously had been incorrectly postulated that the medial meniscus was the third com-ponent.[2]

• [edit] Terminology• The term "unhappy triad" was coined by O'Donoghue in

1950.[2][3][4] However, since then, this term and the term "terrible triad" have also been used to describe several other combinations of joint injuries, including those of the elbow[5] and shoulder.[6]

• The term "terrible triad" is also sometimes used in the popular press to describe conditions relating to pain, or even to refer to the MacDonald triad of sociopathic behav-ior.

uncovertebral hypertro-phy

Ghelman, B, Freiberger, RH. The limbus vertebra: an anterior disc

herniation demonstrated by discography. Am. J. Roentgenol. 1976 127:

854-855.

• Limbus vertebra– A limbus vertebra is a defect in the anterior margin of the vertebral body – The anterosuperior corner of a single vertebral body in the mid lumbar spine is most fre-

quently affected. – The inferior and posterior margin and other re-

gions are less frequently affected. – Limbus is a common radiologic finding. – Results from an intra-vertebral body herniation

of disc material (Schmorl's nodes is a more central herniation into the vertebral end plate).

– The anterior herniation of the nucleus pulposus may cause a separation of a triangular smooth bone fragment which apparently represents the ring apophysis. – This ring apophysis remains separate from the vertebral body.

• Imaging Findings for Limbus verte-bra– Triangular bone fragment at anterosu-

perior corner of a vertebral body.

Am. J. Roentgenol. Haims et al. 180 (3): 647.

(13661K)

• Popliteus tendon• Lateral rotation is always said to occur at

the beginning of flexion and to be due to the muscle popliteus whose tendon inserts onto the outer margin of the lateral condyle of the femur. Popliteus also at-taches to the lateral meniscus and this may ensure that the latter is moved out of the way and not damaged during "unlock-ing" of the knee.

The popliteus tendon originates on the anterior aspect of the popliteus groove just anterior and in-ferior to the origin of the lateral collateral liga-ment and extends inferiorly and medially to insert on the posterior medial aspect of the tibia (Fig. 4A, 4B). The popliteus tendon has strong attachments to the lateral meniscus posteriorly.

Original Text by Clif-ford R. Wheeless, III,

MD.

• Atlantoaxial Subluxation • - refers to loss of ligamentous stability between atlas and axis;

    - occurs most often in older children and adolescents;    - mechanism of injury in atlantoaxial rotatory subluxation is

unknown, but is usually due to forced rotation of the neck along w/ some element of lateral tilt;

               - pts complain of neck pain, occipital neuralgia, and

occassionally symptoms of vertebrobasilar artery insufficiency;    - prognosis:            - significant potential for continued displacement of

atlas on axis w/ resultant pressure on spinal cord;            - vertebrobasilar artery insufficiency may lead to

cerebral infarcts;    - Atlanto-Axial Articulation:            - approx 50 % of cervical rotation takes place between

atlas and axis, around laterally central but anteriorly eccentric odontoid process;

            - lateral wall of atlas rotates to across canal of axis, physiologically decreasing opening between these 2 segments;

            - spinal canal of the atlas is large compared w/ that of other segments, which rotation around axis along w/ translational

             displacement without pressure on the spinal cord;            - Steele's Rule of Thirds:                    - canal of atlas is about 3 cm in its AP diameter;                    - spinal cord, odontoid process, and free space for cord

are each about 1 cm in diameter;                    - anterior displacement of the atlas that exceeds one

centimeter may jeopardize the adjacent segment of spinal cord;

Radiographs:    - Lateral View:          - ADI < 3.5 mm in flexion, implies that the transverse ligament is

intact;          - ADI 3-5 mm, transverse ligament is insufficient;

(this is a type II injury);                - in children upto 4.5 mm may be normal;          - ADI > 5 mm:                - indicates failure of the alar ligaments;                - consistent w/ type III rotatory subluxation;

Wikipedia

• Calcific tendinitis• Calcific tendinitis (also calcific/

calcifying/calcified/calcareous tenonitis/tendonitis/tendinopathy, and tendinosis calcarea) is a disorder charac-terized by deposits of hydroxyapatite (a crys-talline calcium phosphate) in any tendon of the body, but most commonly in the tendons of the rotator cuff (shoulder), causing pain and inflammation.

• Pain is often aggravated by elevation of the arm above shoulder level or by lying on the shoulder. Pain may awaken the patient from sleep. Other complaints may be stiffness, snapping, catching, or weakness of the shoulder.

• The condition is related to and may cause frozen shoulder.

• The calcific deposits are visible on X-ray as discrete lumps or cloudy areas. The deposits look cloudy on X-ray if they are in the process of re-absorption, and this is also when they cause the most pain. The deposits are crystalline when in their resting phase and like toothpaste in the re-absorptive phase. However, poor correlation exists be-tween the appearance of a calcific deposit on plain x-rays and its consistency on needling.

Original Text by Clifford R. Wheeless, III, MD.

• Bipartitie patella• Discussion:

    - a common congenital fragmentation or synchondrosis of the patella     - occurs in approximately 1% of population but some have ob-served a much higher incidence;     - most remain asymptomatic, but direct trauma may disrupt the synchondroses, causing symtoms that mimic those of fracture;     - classification:           - type I: inferior pole of the patella;           - type II: lateral margin type;           - type III: superolateral type;     - diff dx:           - stress frx: look for verticle fracture line;           - Sindig-Larsen-Johanssen disease may resemble a type I bi-partite patella;           - patellar sleeve fracture           - osteochondral frx:                  - is distinguished from biparte patella:                        - on basis of history of trauma;                        - hemarthrosis of knee;                        - point tenderness over defect                        - distinct outline of frx on radiographs;                        - unilateral defect (less than 45% of patients will have bilateral bipartite patella);                        - rapid resolution of symptoms w/ fracture (w/ immobi-lization);

- Treatment:     - type I patella:           - patient with type I bipartite frx (lower pole) may at risk for fracture;           - patients that present with pain and tenderness at the lower pole, should have all activites curtailed;           - fractures occur along the synchondrosis and when displaced, operative fixation is considered;     - type III patella:           - superolateral bipartite patellae may become symptomatic and in some cases may require excision;           - also consider limited detachment of vastus lateralis from the bipartite fragment which removes the stress on the fragment and which can allow spontaneous union;

Original Text by Clif-ford R. Wheeless, III,

MD.

• Talocalcaneal Coalition• - See: Tarsal Coalition:

- Discussion:    - talocalcaneal coalitions are characteristically on medial side of sub-talar joint;    - coalition tends to ossify between 12 and 15 years;    - although coalition between calcaneus & talus may occur in any of three facets, middle facet is most commonly involved;           - note that the anatomy of the middle & anterior facet may vary among individuals;           - four patterns are recognized;                 - a single, small middle facet;                 - a single middle facet that extends posteriorly and is almost as large as the posterior facet;                 - middle facet that extends anteriorly                 - two facets - middle & anterior facet- in medial compartment;    - classification of coalition:           - type I: osseous bridging of the middle facet joint;           - type II: cartilagenous coalition;           - type III: fibrous coalition;                 - shows only slight narrowing of the middle facet joint;                 - the coalition is located posterior to the sustentaculum tali (and in most cases standard CT scan protocols do not image this area);                 - these can be difficult to detect and may require bone scan to make the dx;

- Clinical Manifestations:    - talocalcaneal coalition generally becomes symptomatic in early teenage years when the preexisting cartilagenous coalition ossifies;    - patients often note repeated ankle sprains and may not be able to partici-pate in sports;    - contraction and spasm of the peroneal muscles w/ forced inversion may be noted;    - subtalar motion is reduced;    - in few pts w/ large middle facet, tarsal tunnel syndrome develops from pressure on the median plantar nerve;    - large middle facet may also prevent full plantar flexion of the ankle, since it abuts the posterior portion of ankle joint;             - in these patients, resection will not improve subtalar motion;

- Radiographic Features:

- CT Scan:     - can be used to make the diagnosis and can also be used to judge the rela-tive size of the coalition;