**1. Basic shoulder anatomy**

The shoulder is a ball and socket type of synovial joint. It is one of the largest and most complex joints in the body. Its dynamic and hypermobility make it susceptible to many injuries.

DOI: 10.5772/intechopen.76187

The shoulder girdle comprises of glenohumeral joint, acromioclavicular joint, scapulothoracic articulation, and coracoclavicular articulation.

Deltoid, one of the strongest muscles in the body, encircles the shoulder joint all around. It provides the shape and bulk to the shoulder joint. It works in almost all the functions of the joint from forward flexion, abduction, and adduction to rotations. It is supplied by the axillary nerve. The pectoralis major and minor, rhomboids, latissimus dorsi, teres major, and trapezius are other major muscles that play an important part in the function and stability of shoulder girdle (**Figure 1**).

Rotator cuff provides concentric compression, dynamic stability, and smooth arc of motion to the glenohumeral joint. The subscapularis along with the anterior part of the supraspinatus provides excellent anterior stability. The posterior part of the supraspinatus, infraspinatus, and teres minor provides posterosuperior stability and resists superior pull of deltoid. In addition to the glenoid labrum, rotator cuff muscles are the dynamic stabilizers of the shoulder joint. Injury, dysfunction, or degenerative tears of these muscles hampers the shoulder function to a great extent.

The subdeltoid bursa cushions and protects the tendons of the rotator cuff. It also provides nutrition and lubrication to the rotator cuff tendons. The subacromial bursa can get inflamed in impingement syndrome, RA, calcific tendinitis, and other subacromial painful pathologies causing severe pain and movement restrictions [1].

#### © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### 2 Advances in Shoulder Surgery

Rotator cuff tears can be traumatic or degenerative in older age groups from repeated overuse. It causes pain, functional, and motion restrictions. As per the recent research publications, many patients with full-thickness rotator cuff showed fair to good functional results. These are called compensated rotator cuff tears. On the contrary tear goes on progressing over the period. Patients who do not improve with all these conservative measures are treated with either open or arthroscopic repair techniques. Arthroscopic techniques are far better than the open one, giving the patient the benefits of minimally invasive surgery, anatomic repairs, and

Introductory Chapter: Shoulder Joint http://dx.doi.org/10.5772/intechopen.76187 3

Shoulder dislocation can be anterior, posterior, or multidirectional. It can be traumatic or due to generalized ligament laxity. Traumatic dislocations are usually associated with tear of the labrum, humeral head bony defect, capsular tears, and muscle and nerve injuries. In emergency settings it is reduced under anesthesia, and sling is applied followed by physiotherapy. Most of the patients do well with this, but if it becomes recurrent due to capsulolabral nonhealing, big humeral bone defect (Hill-Sachs lesion), and/or glenoid bone loss, surgery is indicated. Most of the patients can be managed with arthroscopic repair, but few may require

Since the biceps plays an important role in shoulder stability and function, many biceps pathologies may cause pain and disability. Biceps tendon problems like tendinopathy or tenosynovitis as well as SLAP lesions compromise optimal shoulder function and may result in impingement. Biceps tenotomy in older population and tenodesis in younger patients are the

Glenohumeral internal rotation deficit, often referred to as GIRD, is a sport-specific adaptation of posterior shoulder structures to chronic excessive overload of these structures during frequent throwing. Burkhart et al. [13] report that GIRD occurs before any other motion adaptation, suggesting that contracture of the posterior capsule is to blame for this change in range

rapid recovery (**Figure 2**).

bony procedures like Latarjet, etc. (**Figure 3**).

treatments of choice (**Figure 4**) [3].

**Figure 2.** Arthroscopic view of Rotator cuff tear.

**Figure 1.** Muscles and nerves.

On the inner most aspect of the joint is an intracapsular structure called glenoid labrum which not only deepens the glenosphere but also provides strong all-round stability to the shoulder joint through the tension and compression it creates through capsular ligaments like superior, middle, and inferior glenohumeral ligaments in association with rotator cuff. The anterior part of inferior glenohumeral ligament is the most important anteroinferior stabilizer. Long head of biceps originating from the superior labrum helps in shoulder stability.

The shoulder joint is surrounded by many neurovascular structures like the brachial plexus, axillary nerve, suprascapular nerve, musculocutaneous nerve, brachial artery, and lungs. These structures are always vulnerable to injury in shoulder trauma.
