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Xray of Wrist Showing Carpal Bones

May 20, 2012 By Leave a Comment

Xray of wrist showing carpal bones.

Each carpal bone has been marked. Readers not used to read xrays might have in understanding overlapping bones.

Carpal Bones

Carpal Bones- See theText For Details

The carpus has eight bones in two rows

The proximal row consists of the scaphoid, the lunate, and the triquetrum.

The distal row consists of Trapezium, trapezoid, capitate and hamate.

In the xray the bones have been mareked as follows.

S – Scaphoid
L- Lunate
T – Triquetrum
P – Pisiform
Tm – Trapezium
Td – Trapezoid
C – Capitate
H – Hamate

Filed Under: Musculoskeletal Anatomy, Musculoskeletal Radiology, Orthopaedic Images Tagged With: , , ,

Lamina

April 10, 2012 By Leave a Comment

Lamina means a very thin layer. [Plural - laminae]

In medicine, lamina mostly refers to lamina of vertebral arch.

The laminæ are two broad plates, extending dorsally and medially from the pedicles. [See image below]

Lamina Vertebra

The both laminae fuse posteriorly and along with pedicles they constitute vertebral arch.

Filed Under: Definitions, I-M, Musculoskeletal Anatomy, Spine Tagged With: ,

Os Vesalianum

February 10, 2012 By 1 Comment

Os vesalianum pedis is an accessory bone of the foot located proximal to the fifth metatarsal and found within the peroneus brevis tendon. It is a rare occurrence [Incidence-0.1% and 0.4%]

The Os Vesalianum should be differentited in cases of fifth metatarsal avulsion fracture, ossifying apophysis of the fifth metatarsal base, Iselin’s disease, an ununited apophysis of the fifth metatarsal base and a fracture of the tuberosity of the fifth metatarsal, nonunion of a tuberosity fracture of the fifth metatarsal and an os peroneum. [Read more...]

Filed Under: Definitions, Musculoskeletal Anatomy, N-R Tagged With: , , ,

Anatomical Considerations In Treatment Of Distal Radius Fractures

December 28, 2011 By Leave a Comment

The distal radius is made up of metaphysis and  three articular surfaces

  • Laterally the scaphoid facet
  • Medially, the lunate facet
  • Sigmoid notch for distal radio ulnar joint

The ulna plays an important part of the ligamentous integrity of the DRUJ and TFCC.

The metaphysis is flared distally in both the AP and the lateral planes.

There is a thin cortical bone on dorsal and radial aspect making the fractures typically collapse dorsoradially. [Read more...]

Filed Under: Musculoskeletal Anatomy, Wrist Injuries Tagged With: , , , ,

Radial Length In Distal End Radius

December 16, 2011 By Leave a Comment

It is also called radial height.

Radial length is measured on the postreoanterior radiograph.

It is measured as the distance between following two lines.

First line is drawn perpendicular to the long axis of the radius passing through the distal tip of the radial styloid.

Second line is along the articular surface of radius.

The average value of this measurement averages 10-13 mm.

http://www.radiologyassistant.nl/images/477754a4cbaf0radial-height.jpg

Filed Under: Musculoskeletal Anatomy, Musculoskeletal Radiology, Wrist Injuries Tagged With: , , ,

Radial Inclination

December 16, 2011 By 1 Comment

Radial inclination is also termed as radial angle.

This measurement is taken in posteroanterior radiograph of the wrist.

Radial inclination represents the angle between one line connecting the radial styloid tip and the ulnar aspect of the distal radius and a second line perpendicular to the longitudinal axis of the radius.

Radial Inclination

Radial Inclination

The radial inclination ranges between 21° and 25°.

Radial inclination value would change in  fractures of articular surface.

Loss of radial inclination will increase the load across the lunate.

Filed Under: Musculoskeletal Anatomy, Musculoskeletal Radiology, Wrist Injuries Tagged With: , ,

Erb’s Point

December 9, 2011 By 1 Comment

Also called punctum nervosum, Erb’s point is a a landmark of the brachial plexus on the upper trunk, located about 1 inch (2.5 cm) above the clavicle at about the level of the sixth cervical vertebra.

It is located on the posterior border of the sternocleidomastoid muscle midway between its attachments to the mastoid process, and the sternum and clavicle.

Erb’s point is formed by the union of the C5 and C6 nerve roots, which later converge. Branches of suprascapular nerves and the nerve to the subclavius also merge. The merged nerve divides into the anterior and posterior division of C5 and C6.

Injury to Erb’s point is commonly sustained at birth or from a fall onto the shoulder.

The nerve roots normally involved are C5 and partly C6. [Read more...]

Filed Under: Definitions, E-H, Musculoskeletal Anatomy Tagged With: , ,

Distal Radio Ulnar Joint

December 1, 2011 By 1 Comment

The distal radioulnar articulation or inferior radioulnar joint is a joint formed between the head of the ulna and the ulnar notch on the distal radius.

The articular surfaces are connected together by the following ligaments:

  • Volar radioulnar ligament
  • Dorsal radioulnar ligament
  •  Articular disk (Triangular fibrocartilage)

Triangular fibrocartilage complex is ulnar continuation of distal radius & presents concave surface for articulation with lunate and triquetrium. [Read more...]

Filed Under: A-D, Definitions, Joints, Musculoskeletal Anatomy Tagged With: , ,

What is Ulnar Variance?

November 30, 2011 By 3 Comments

Ulnar variance refers to the difference between the levels of radial and ulnar articular surfaces. Normally, the articular surface lies slightly in distal position than the ulnar articular surface.

Ulnar variance is said to be neutral if articular surfaces of radius and ulna are at the same level.

Ulnar variance is positive if ulnar articular surface is distal to radial.

Ulnar variance is Negative if ulnar articular surface is proximal to radial.

Normal Ulnar Variance

There are a lot of studies measuring ulnar variance. Most cited value of  mean ulnar variance is 0.9 mm (range: -4.2 to +2.3 mm) [ref-Schind et al]

Ulnar variance determines the distribution of load in wrist joints. If ulnar variance is neutral, 80% of load is born by radius and 20% by ulna. [Read more...]

Filed Under: Musculoskeletal Anatomy Tagged With: , ,

Atlanto Axial Joint

March 11, 2011 By Leave a Comment

The Atlas or C1 is the first bone in the neck,  is simply a ring, with facets above and below to articulate with occiput above, and the Axis (C2) below.

The Axis (C2) too is quite unique. There is a pivot articulation between the odontoid process of the axis and the ring formed by the anterior arch and the transverse ligament of the atlas.

Atlas and Axis Vertebrae

Image Credit: http://www.chiropractic-help.com/Atlanto-axial-joint-anatomy.html

 

 

There are two atlanto-axial joints: median and lateral. [Read more...]

Filed Under: A-D, Cervical Spine, Definitions, Musculoskeletal Anatomy Tagged With: , ,
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