SHOULDER

Hombro

The shoulder is one of the most complex parts of the human body in design and functionality and is considered the joint with the greatest range of motion.

It allows us to perform simple actions like lifting objects or scratching our back as well as large, complex movements like swimming, climbing, and throwing objects long distances. Many different structures play a role in the process of granting us such mobility; these same structures open the door to a wide range of possible injuries.

The shoulder is formed by the humerus, shoulder blade, and clavicle, however this is only the bony frame. The joint’s functional mobility is due to a complex musculotendinous unit, which is why the shoulder suffers such a high rate of sports-related injuries or degenerative injuries caused by daily activities. The main culprit behind shoulder injuries is mechanical. That is to say that what went wrong, be it in the part of the shoulder that creates stability or mobility, is due to trauma, a fall, or from overuse.

The type of injury depends as much on the activity the patient is engaged in as on the patient’s age and timeframe in which the injury developed.

 

DEGENERATIVE INJURIES

This type of injury is associated more with age-related problems and activities repeated over the course of a lifetime, and may be related to previous injuries, treated or untreated.

The most common are those associated with the degeneration of the shoulder tendons, better known as the rotator cuff.

Rotator Cuff Injuries

The humeral head is in direct relation to the glenoids (the bony counterpart to the scapula) and joined at the joint capsule. The principal muscles in charge of shoulder movement are the following:

  • • Supraspinatus muscle
  • • Infraspinatus muscle
  • • Subscapularis muscle
  • • Teres minor muscle

These muscles, in turn, insert themselves into the humeral head through their tendons, meaning that each muscle, to be joined to the bone, needs a tendon, and these tendons share the same name as the muscles they are attached to.

These tendons make up what is known as the rotator cuff.

The rate of injury is higher in the tendon that initiates abduction (moving the arm away from the body) and is called supraspinatus. 

 

Massive Rotator Cuff Tears

When two or more tendons are torn, the injury is considered massive. It is more commonly found in patients 60 years or older and technically is the most difficult to repair.

Repairing it depends on the tendons that are affected.

It’s important that these injuries, due to the deficiency they create, are repaired according to the mechanical alteration they produce, and therefore usually engender another type of problem, known as Rotator Cuff Arthropathy.

 

Supraspinatus Tendon Injury

This is the most common injury, with pain experienced in the shoulder over a long period of time.

This injury is associated with a mechanical deficiency in the shoulder caused by different reasons. One of them is the shape of the acromion (the bone above the tendon). When performing movements of flexion (arm moving forward) and rotation (both internal and external) the tendon is pinched between the humeral head and acromion.

This condition better known as subacromial impingement may, either chronically o acutely, tear the tendon. The type of condition is often accompanied by a sensation of “popping” in the shoulder during movements.

It’s important to know that, in spite of the tendon being torn, the shoulder is capable of compensating with its strongest muscle: the deltoids. This permits most patients, in spite of the pain, to the move the shoulder almost normally.

Mechanically the supraspinatus tendon is incapable of healing at its insertion point due to the force of the muscle upon it.

This injury requires a arthroscopic repair; returning the tendon to its place and setting it through various methods, the most common is to set it with anchors. 

 

Subscapularis Tendon Injury

This injury is related in an indirect way to a problem in the biceps pulley. The subscapularis tendon is in charge of performing internal rotation (bringing the hand to the back).

Tearing this tendon not only produces pain but also limits the force of internal rotation. If the long biceps tendon is affected, it is quite common to experience pain during external, as well as internal, rotation.

Similar to injuries in the supraspinatus tendon, mechanically the tendon is unable to return to its insertion point, thus an arthroscopic repair is the only method to reestablish its full function.

 

Glenohumeral arthrosis

The shoulder, as with the humeral head and the glenoids, moves thanks to cartilage. The joint cartilage may be lost for various reasons, such as previous surgeries, traumas, insufficient blood flow the humeral head, or for idiopathic or unknown reasons.

The loss of joint cartilage generates constant pain in the shoulder and progressive loss of mobility, along with continuous “popping.”

In the case of specific cartilage loss that doesn’t affect rotator cuss integrity, treatment focuses on replacing the cartilage with an artificial surface layer.

 

Rotator Cuff Arthropathy

When the rotator cuff ceases to function for a prolonged time, the general mechanics of the shoulder are abnormal and stresses the forces that hold the humeral head in place.

This condition always wears away at the humeral head. This pathology produces chronic pain that does not improve with medication or with physical therapy. Shoulder mobility is seriously compromised. Because this injury disables tendon function and the humeral head suffers wear and tear, the entire joint is incapacitated.

The treatment of choice for this problem is a complete replacement of the joint, better known as shoulder prosthesis. However, this is not a conventional prosthesis, but one that substitutes the dysfunctional tendons. This shoulder prosthesis is a reverse anatomy replacement and provides a replacement of the injured parts.

This surgery is technically more demanding and requires special care, such as in-depth knowledge of the injury and the technique.

 
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background
Slide background