Upper Limb Joints

1. Plane Joints

• Acromioclavicular Joint: The joint surface includes the acromial facet of the acromion, the clavicular facet of the lateral end of the clavicle, and the articular disc.

• Sternoclavicular Joint: The joint surface includes the sternal end of the clavicle, the clavicular notch of the sternum, and the articular disc.

• Radiocarpal Joint: The joint surface includes the radius, scaphoid, lunate, and triquetrum.

2. Shoulder Joint

• Type of Joint: Ball and socket joint.

• Joint Surfaces:

• Head of the humerus.

• Glenoid cavity of the scapula (joint socket).

• Glenoid labrum.

• Weak Point: Located between the superior and inferior glenohumeral ligaments.

• Dislocation: Anteriorly, the acromion is not visible (sign of a “humped shoulder” / “saber cut”).

• Approach to Joint: Incise along the anterior border of the Deltoid muscle (following the deltopectoral groove).

3. Elbow Joint

• Includes:

• Humeroulnar joint (hinge joint).

• Humeroradial joint (condyloid joint).

• Proximal radioulnar joint (pivot joint).

• Cartilage Lining: Present at the elbow joint.

• Approach to Joint: Incise in the posterior aspect (along the midline of the olecranon process).

4. Wrist and Hand Joints

• Joint 1: Saddle joint.

• Carpometacarpal joints: Ball and socket joints.

5. Triangular Ligament

• A fibrocartilaginous sheet, acting as an articular disc between the ulna, triquetrum, and lunate.