SHOULDER ANATOMY
In order to understand the different conditions that can affect the shoulder joint an understanding of the basic anatomy of the joint is important.
In order to understand the anatomy of the shoulder joint, it is important to note that the joint consist of a round ball (humeral head) that articulates on a flat surface (the glenoid) with no bony contour to keep the humeral head in place.
Therefore, in the shoulder joint the surrounding ligaments and muscles are vitally important for function and stability of the joint.
Anatomy Explained.
Bone Components
Humerus head: Upper arm bone
The upper part of the humerus is called the head and it articulates with the glenoid.
Scapula: Shoulder blade
The scapula has four parts that form an integral part of the joint.
Glenoid:
This is the flat surface that articulates with the humeral head.
Acromion:
This is the protrusion at the top of the shoulder joint.
Coracoid:
This is the protrusion on the inside (medial side) of the glenoid.
Blade of the scapula:
The blade of the scapula moves and articulates against the chest wall at the back.
Clavicle: Collar bone
The clavicle forms the upper part of the joint with the acromion and has a stabilization function on the joint.
Joints that form part of the shoulder girdle:
Humeral joint:
(that is the shoulder joint) (GH joint). This is the articulation between the humeral head and the glenoid. This is a very mobile joint with a wide range of movement.
AC joint (Acromioclavicular joint):
This is the articulation between the inner edge of the acromion and the outer end of the clavicle. This is a non-mobile joint with a limited range of motion.
Ligaments
A ligament is a structure connecting between two bony components for stability.
Ligaments of the glenohumeral joint:
There are multiple ligaments in the front and the back of the glenohumeral joint that attached between the glenoid and the upper part of the humerus. They are all an integral part of the joint capsule (this is the structure that surrounds and defines the joint cavity) and the associated tendons.
Ligaments of the AC joint:
There are four important ligaments that play a part in the stability of the AC joint.
Two ligaments form a direct part of the joint at the top and the bottom of the joint (the AC joint ligaments).
The ligaments that attached to the top part of the coracoid and the bottom part of the outer third of the clavicle (the conoid and trapezoid ligaments).
The coraco-acromial ligament (CA ligament):
The CA ligament attaches on the inside edge of the acromion and stretches to the outside edge of the coracoid. It forms part of the roof of the subacromial space (discussed later).
Tendons
A tendon is the attachment of a muscle to bone. Important tendons in the shoulder joint are as follows:
Rotator cuff (upper):
The upper part of the rotator cuff is formed by fusion of the supraspinatus and infraspinatus and teres minor tendons. These tendons form the upper part of the glenoral humeral joint and attaches to the outside of the humeral head (on the greater tuberosity).
Rotator cuff (lower):
The lower or (front) part of the cuff is formed by the subscapularis tendon and attaches to the front part of the humeral head (on the lesser tuberosiry).
Biceps tendon:
This tendon is one of the attachments of the biceps muscle. It is a thin round structure that runs in a long groove on the humeral head into the glenural humeral joint and attaches to the top part of the glenoid labrum (discussed later).
Pectoralis major tendon:
The pectoralis major muscle tendon runs in front of (anterior) and below (inferior) to the glenoral humeral joint and attaches to the upper part of the humerus.
Conjoint tendon:
The conjoint tendon is the tendon that is been formed by fusion of the other head of the biceps muscle as well as the brachialis muscle and the tendon attaches to the tip of the coracoid.
Join Spaces
Glenohumeral joint space:
This is the space between the glenoid and the humeral head and is the true shoulder joint space.
Sub-acromial space:
This space is formed between the acromion and the AC ligament and the rotator cuff at the bottom. This space is filled with the sub-acromial bursa.
A bursa is a fluid filled sack inter positioned between a bony area and tendon to facilitate easy movement with less friction between these two structures.
The AC joint space:
The space between the acromion and the clavicle. This space is filled with a cartilage insert for joint stability.
OTHER IMPORTANT SOFT TISSUE STRUCTURES
The glenohumeral joint capsule:
The capsule is the sack surrounding the joint that defines the joint space.
The glenoid labrum:
The labrum is a structure that attaches circumferentially onto the edge of the glenoid. It plays a very important role in the stability (location) of the humeral head on the glenoid. It also serves as the point of attachment of various of the ligaments and is important for stability of the glenohumeral joint.
Understanding the anatomy gives a much better understanding of the pathology and surgery involving the shoulder joint.
Consultation.
APPOINTMENTS
To book an appointment for a consultation please contact the rooms on 021 883 9311.
When you come for the first appointment please bring the following:
- Referal letter from your GP or physiotherapist (although this is not compulsary, it is always preferred).
- Medical Aid details (Card)
- Copies of previous x-rays, CT Scans, Ultrasound or MRI or reports related to the above and any other information relevant to your condition.
- If you had any previous surgery, any information regarding this surgery might be very helpful.
- Workman’s Compensation claim details if applicable.
CANCELLATION OF YOUR APPOINTMENT
If at all possible, it will be appreciated if appointments can be cancelled 48 hours prior to the appointment.
INITIAL CONSULTATION (FIRST CONSULTATION
The cost of the first consultation is South African Rand. This is payable on the day of consultion and a portion can be claimed from your medical aid. (The amount claimed from your medical aid may differ between medical aids and options)
FOLLOW UP CONSULTATION
You may be required to return for a review consultation. This might be either for re-assesment or to discuss results after futher investigation. The cost of this consultation is South African Rand and again a portion can be claimed from your medical aid.
POST OPERATIVE CONSULTATION
On discharge from the hospital post surgery arrangements will be made for follow up consultations post surgery. These are important for accessing progress and rehabilitation. These consultations are free for the first eight weeks post surgery.
EXTRA COSTS
At times a extra minor procedure might be performed associated with the consultation i.e. a steroid injection or ultrasound examination. This will incur extra cost which also can be claimed from your medical aid (partially or fully).
PAYMENT INFORMATION
Payment is required at the time of your consultation. Payment can be made in cash, credit card of EFT. As already mentioned a portion can then be claimed from your medical aid if applicable.