The Shoulder Joint also called the Gleno-Humeral joint is a ball and socket like structure between the scapula and the humerus. It is the major joint connecting the arm to the thorax. It is the most mobile joint in the human body and as such it is frequently injured. The shoulder joint is formed by the articulating surface of the humerus and the scapula. They are joined at the glenoid fossa of the scapula. Therefore, the synonym, glenohumeral joint.
As with all synovial joints, the articulating surfaces are covered with cartilage and bathed in synovial fluid. As the head of the humerus is much larger than the fossa and can be placed in a wide range of motions, there is inherent instability. The glenoid labrum is a fibrocartilage rim that stabilizes the joint.
Major Ligaments of the Shoulder Joint
The major ligaments stabilize the humerus from dislocating out of the joint space.
- Transverse humeral ligament- Holds the bicep tendon in place in the bicipital groove
- Glenohumeral ligament- Major source of stability and prevent anterior dislocation
- Coracohumeral ligament- supports the superior portion of the capsule
- Coracoclavicular ligament- maintain the clavicle in relation to the scapula
- Coracoacrominal ligament- forms an arch and prevents superior displacement of the humeral head
Movements of the joint
As a ball and socket joint there is a wide range of motion. The range of motion is caused by action of the rotator cuff acting on the humerus. The wide range of mobility causes a lack of stability.
The movements of the joint are:
- Extension- the arm moves backward- caused by pectoralis major, latissimus dorsi and the teres major
- Flexion- upper limb moves forward- pectoralis major, deltoid and coracobrachialis
- Abduction- the arm moves away from the body at the side- produced by the supraspinatus and deltoid
- Adduction- arm is moved back to the side- produced by pectoralis, latissimus dorsi and teres major
- Internal rotation- rotation toward the midline so that the thumb is pointing medially- subscapularis, pectoralis, latissimus, deltoid and teres major
- External rotation- rotation away from midline so the thumb is pointing laterally- infraspinatus and teres minor
- Circumduction- moving in a circle- combination of all the movements
Four muscles comprise the rotator cuff:
- Teres Minor
Rotator cuff tears often occur in people who repeatedly perform the same shoulder motions. They are very common in the U.S., about 3 million cases per year. All the tendons in the rotator cuff attach to the humerus, in a rotator cuff tear, the tendon is no longer fully attached to the boneThe supraspinatus is the most common tendon torn. Tendon tears begin by fraying and as the damage progresses, the tendon can completely tear away from the bony attachment
Risk Factors for Rotator Cuff Tears
- Occupation- Jobs such as painters or construction workers where the arm is extended overhead
- Diminished blood supply to area as we age-
- Age- most common in people over 60 ,frequently starting at age 40
- Family History- very common in families and there could be a genetic predisposition
- Athletics- where stress is repeatedly placed on the rotator cuff as in base3ball pitchers and cricket
- Bony Spurs- which can rub and fray the tendon ultimately leads to tearing
Different types of rotator cuff tears
- Partial tear also referred to an incomplete tear. There is still some attachment
- Full Thickness tear or a complete tear basically a hole in the tendon and separated from the bone
- Pain at rest especially at night
- Pain on lifting with specific movements
- Weakness or inability to raise arm or hold up against resistance
- When acutely injured, a snap or cracking sensation accompanied with severe pain
- Overall arm weakness that may progress over time
- Pain can be referred down the arm or into neck area
- No symptoms at all but usually arm weakness still present
Usually done during a physical exam by a healthcare professional with a range of motion exam and history
X Rays- may show bony spur formation and arthritis but tears cannot be visualized
MRI- Usually done to make the diagnosis. The tears can be seen and quantified
Ultrasound- tears can also be seen
- Rest- is the principal treatment allowing the inflammation to reduce and healing if possible
- Physical Therapy- strengthening the supporting structures and increase the range of motion
- Drugs- to reduce pain and inflammation such as NSAIDS and Tylenol
- Steroid injections- to reduce inflammation however can further degenerate the area and repeated use is not recommended
- Surgery- even though most tears cannot heal on their own good function can often be achieved without surgery
Types of Surgical Procedures
In cases of deep tears or complete tears where greater than 90% of the tendon is torn and symptoms cannot be controlled with conventional therapy. However, some patients with massive rotator cuff tears may still have good active range of motion by balanced forces across the glenohumeral joint and recruitment of other muscles such as the deltoid. However, this can still cause weakness and pain and repetitive overhead movement may not be accomplished
- Mini open- using a smaller incision and arthroscopic visualization with less instrumentation if possible
- Tendon Transfer- tendon taken from another area and transplanted into the area for repair
- Shoulder replacement
Platelet-Rich-Plasma is an autologous blood product presenting a super-physiologic concentration of growth factors, cytokines and other regenerative properties. The many factors contained in Platelet-Rich-Plasma are essential for cell recruitment, multiplication and specialization required in tissue healing.
Platelet- Rich-Plasma can be used both as a treatment in partial tears in the rotator cuff as well as post operatively in the treatment for full thickness tears where surgery has been deemed the only option.
(Use of Platelet-Rich-Plasma for the Improvement of Pain and Function in Rotator Cuff Tears: A Systemic Review and Meta-Analysis
Am J Sports Med 2020 Jul;48(8)_: 2028-2041 PMID 31743037)
The purpose of this analysis was to assess the efficacy of PRP for rotator cuff related abnormalities and evaluate specific tendon involvement , the inclusion of leukocytes, and the use of gel formulations affect pain and functional outcomes.
A total of 18 level 1 studies were included in this review, with a total of 1116 patients.
Conclusion: Patients who received PRP were significantly better short term. Long term re-tear rates were significantly decreased in the PRP treated patients and significant improvements in the PRP groups for multiple outcomes. Overall, the results suggest PRP may positively affect clinical outcomes
(The Efficacy of Injections for Partial Rotator Cuff Tears: A Systemic Review J Clin Med 2020 Dec 25;10(1):51 PMID 33375716)
The purpose of this review is to compare corticosteroid injections to other drugs in the treatment of partial rotator cuff teras focusing on effectiveness in terms of pain and shoulder functionality. Nine studies were included and a total of 494 patients
Conclusion: The treatment of partial rotator cuff tears with PRP seems to lead to significant better outcomes in terms of pain and shoulder function in the long term
(Efficacy of Intraoperative Platelet-Rich-Plasma Augmentation and Platelet -Rich-Plasma Booster Injection for Rotator Cuff Healing: A Randomized Controlled Clinical Trial J Sports Med 2021Jun4;9(6):232596712110006100 PMID 34159208)
The purpose was to assess the efficacy of intraoperative augmentation and postoperative injection of PRP in patients with arthroscopic rotator cuff repair
Conclusion- Intraoperative PRP augmentation during arthroscopic repair demonstrated superior anatomic healing results in patients as well as reduced pain and increased subjective satisfaction. In patients with tears greater than 2 cm, the rate of healing failure at 1 year follow up was significantly less in the PRP group.
(Platelet-Rich Product Supplementation in Rotator Cuff Repair Reduces Retear Rates and Improves Clinical Outcomes: A Meta-Analysis of Randomized Controlled Trials
Arthroscopy 2021 Aug;37(8):2608-2624 PMID 33744318)
The purpose of this study was to conduct a comprehensive systemic review and meta-analysis to investigate the clinical and imaging outcomes of types of PRP therapies in rotator cuff repairs.
Conclusion- the analysis demonstrated significant reductions in retear rates and clinical outcome scores when rotator cuff repair is augmented with PRP
Juventix Regenerative Medical offers a FDA approved Platelet-Rich-Plasma Kit that is not only cost effective but easy to use. The Juventix kit provides scientifically proven repeated outcomes when taken from the same source.
Juventix has a patent pending LED activation process that activates the platelets without the use of additives such as Thrombin or Calcium Chloride.
Juventix Bio-Incubator allows the PRP to be converted to Injectable Platelet Rich Fibrin to augment the overall healing process.
Restore, Revive, Regenerate – Juventix Regenerative Medical
Dr. Robert McGrath