Shoulder Resources

Shoulder and elbow injuries in the throwing athlete (R) Shoulder and elbow injuries in the throwing athlete (R)


Rotator cuff tears

Demands on the rotator cuff
In the acceleration phase of throwing angular velocities of 7000 degrees/second are generated.
In late cocking anterior glenohumeral translation forces of up to 40% of body weight are generated.
In follow through phases, glenohumeral distraction forces of 1 to 1.5 times body weight are generated.
The rotator cuff also has significant demands placed on it during swimming, particularly freestyle and butterfly; in a survey of Canadian swimmers 15% had impingement syndrome.

Role of rotator cuff
The rotator cuff acts to hold the humeral head in the glenoid, while muscles with longer lever arms generate movement of the humerus.

Rotator cuff lesions
The rotator cuff is subjected to repeated abnormally high tensile and compressive forces. These can eventually lead to tendon inflammation, degeneration and tear. Both intrinsic and extrinsic factors predispose to the tendon degeneration:
Extrinsic factors include compression, tensile overload and repeated stress.
Intrinsic factors include alterations in tendon vascularity, impaired healing response and alterations in matrix composition.
Rotator cuff abnormalities can result from primary cuff failure, or secondary to conditions such as instability.
The articular (undersurface) side of the cuff is weaker than the bursal side of the cuff and more prone to tearing. It is subject to greater shear forces. Accordingly, joint side tears are more common than bursal side tears.
There are different mechanisms of injury of the rotator cuff:
• Primary impingement: the cuff is compressed against the coracoacromial arch, undersurface of the acromion, acromial spur or os acromiale. The classic Neer impingement syndrome is more common in the older athlete, over 35.
• Primary tensile failure: the cuff tears as a result of the repeated forces upon it.
• Internal impingement: this is defined as impingement of the postero-superior rotator cuff between the humerus and postero-superior glenoid rim, which occurs in late cocking phase when the arm is maximally abducted and externally rotated. This actually physiologic, with 85% of patients demonstrating internal impingement in a position of 95 degrees of abduction and 74 degrees of external rotation
• Glenohumeral instability predisposes to cuff tear. Many throwers have increased laxity of their dominant shoulder, which may be due to capsular stretching anteriorly; they may also have posterior capsular contracture, which can lead to increased translation of the humeral head. Glenohumeral instability puts increased demands on the cuff.

Clinical evaluation
In the history important factors include the patient's age; onset, duration and location of the pain; and the phase of throwing when the pain occurs. Loss of velocity and control can be subtle early symptoms of rotator cuff disease.
In internal impingement the patient complains of posterior shoulder pain, particularly during the late cocking phase.
Younger patients often have problems with instability and secondary impingement. Older patients tend to have rotator cuff degeneration from primary impingement.
Points to note on examination include the normal asymmetry of the thrower's shoulder, and also a tendency towards inferior scapular displacement, and increased external rotation and decreased internal rotation.
Patients with partial thickness rotator cuff lesions often have strength preserved, although pain inhibition may lead to apparent loss of strength and motion. Marked weakness and muscular atrophy imply full thickness rotator cuff tear. Partial thickness rotator cuff tears may be more painful than full thickness tears. Bursal sided PTRCTs are the most painful variety.
Patients with internal impingement may have posterior shoulder pain on external rotation and abduction, which is relieved by pushing the humeral head backwards. In intra-articular lignocaine injection may also relieve pain.

Imaging
Standard XR should include AP in plane of scapula with external and internal rotation, axillary and supraspinatus outlet views.
OKU 7: MRI remains the diagnostic test of choice for evaluation of rotator cuff and labral pathology. Magnetic resonance arthrography can detect partial thickness cuff tears and labral lesions. Its accuracy is increased by the addition of fat-saturation to T2 weighted scans. Gadolinium arthrography may also increase accuracy. Note that Fukoda 2003 says “detection of partial tears by standard MRI techniques is not reliable”.
Typical MRI findings in PTRCTs are increases in signal on T1 and T2 weighted images without evidence of tendon discontinuity on T1 images. Rotator cuff tendonitis will also cause increased signal on T1 images, but moderate or decreased signal on T2 images (check).
The usefulness of ultrasound in detecting partial thickness tears is uncertain. Examination may reveal a focal hypoechoic area, representing fluid within the substance of the rotator cuff.
Classification of partial thickness rotator cuff lesions
The Ellman classification uses both the site of the lesion and the depth of the lesion. (Based on arthroscopic probe with 3mm hook).
Grade I: less than 3mm deep
Grade II: 3-6mm deep
Grade III: more than 50% cuff thickness

Treatment
Initially nonsurgical treatment unless there is a full thickness cuff tear.
The principles of nonsurgical treatment include:
• Elimination of pain, with rest, ice, anti-inflammatories
• Gain of full range of painless motion
• Then start on strengthening of the rotator cuff and scapular stabilizers, including eccentric cuff strength-ening exercises
• Once full motion and strength are regained, gradual return to throwing, during which attention is focused on throwing mechanics.
Hawkins mentions that TENS was useful as a last resort in a group of swimmers who had failed other treatments.
If three months of non-surgical treatment have failed, one should consider surgery. The surgery depends on correct diagnosis of the pathology.
Patients with primary impingement should be treated with arthroscopic subacromial decompression and debridement of the cuff tear. This SHOULD NOT BE DONE IN ATHLETES UNDER 35 BECAUSE THE CHANCE OF RETURN TO PREINJURY LEVEL OF FUNCTION IS POOR. In a series of young athletes treated with arthroscopic decompression and debridement only 45% returned to preinjury levels of competition. These patients should have a debridement only. Andrews' series of throwing athletes with an average age of 22 had 85% good or excellent results when treated with debridement alone.
Primary tensile failure is treated by surgical debridement of the cuff tear if it is less than 50-75% of the cuff thickness. If more than 50% is involved the cuff tear should be taken down and repaired.
Arthroscopic signs of evidence of instability include chondral lesions, labral tears and SLAP lesions. If there is associated instability this must be addressed, eg by open or arthroscopic capsulolabral reconstruction, or thermal capsular shrinkage.
A full thickness tear in a young throwing athlete needs to be repaired immediately but is not likely to do well, with few returning to prior level of competition. The repair should if possible be done via arthroscopic decompression and mini-open repair, which is better at preserving the deltoid.

Surgical treatment of internal impingement
The initial treatment is non-surgical and consists of cuff strengthening exercises focusing on improving glenohumeral instability, and stretching of the posterior capsule.
Surgical treatment is indicated if there is failure of 3 months of non-surgical treatment. At arthroscopy the kissing lesion of posterior labrum and cuff undersurface is debrided. If a SLAP lesion is present it is addressed. If there is posterior capsular laxity, capsular tightening is required.
Bennett lesions
This is an exostosis at the site of the posterior band of the inferior glenohumeral ligament.
It is thought to be caused by excessive traction on the IGHL due to posterior subluxation during cocking and or posterior deceleration forces during followthrough.
Patients may complain of posterior shoulder pain, and there may be tenderness of the posterior inferior glenoid rim.
There is a high association with posterior labral tears and undersurface tears of the rotator cuff.

Little leaguer's shoulder
This is a widening of the proximal humeral physis in young throwing athletes who pitch excessively.
Patients complain of pain localized to the proximal lateral humeral humerus.
Comparison XR are taken.
Treatment is three months' rest.
May result in overgrowth of the humeral head.

Elbow injuries
These typically result from repetitive stress. During late cocking and acceleration phases, tremendous valgus forces are transmitted across the medial aspect of the elbow. These forces are greater than the load to failure of the UCL, so muscle contraction is necessary to stabilize the joint.
The UCL may go on to midsubstance failure.
Lateral compressive forces of 1100 N are developed across the radial side of the joint during late cocking and acceleration, with shear forces during deceleration. These can lead to the development of osteochondral lesions of the radiocapitellar joint, eg osteochondritis dissecans or Panner's disease.

Ulnar collateral ligament injuries

Anatomy of ulnar collateral ligament
There are 3 bands, with the important structure of the anterior oblique band running from the anterior aspect of the medial epicondyle to the medial side of the coronoid process of the ulna, at the sublime tubercle, where it attaches 18mm dorsal to the tip of the coronoid (disrupted by type III coronoid fractures) . The posterior oblique ligament runs more in the line of the humerus to insert along the superomedial border of the olecranon.
Patients complain of medial elbow pain with pitching, decreased accuracy, velocity and pitch count. (Lateral collateral injuries are associated with instability). There is not usually pain with ADLs.
There may be pain along the medial collateral ligament.
Clinical laxity with opening up on valgus stress is seen in only 25%. When assessing for valgus instability, flex the elbow to 25 degrees to unlock the olecranon from the olecranon fossa and minimize contribution of bony congruity to stability. Keep the forearm pronated at the same time to remove possibility of any PLRI.
Ulnar nerve symptoms are common, and there is often an associated Tinel's sign.
XR should include comparison valgus stress views. They may show loose bodies. As little as 0.5mm extra opening on the affected side is significant.
Reconstruction of the ligament is preferred, and this is most commonly done with a palmaris longus graft passed through bony tunnels in a figure of eight fashion. If the ulnar nerve is symptomatic it is transposed. Calcified tissue is excised.
Return to normal level of activity is expected in 80%, although this may take a year.

Valgus extension overload
This is a spectrum of injuries comprising posterior medial olecranon impingement, UCL injury, flexor pronator injury and radiocapitellar overload.
Excessive elbow valgus can lead to the olecranon impinging on the medial edge of the olecranon fossa, causing the development of osteophytes that further narrow the fossa.
Patients complain of pain during the acceleration phase of pitching.
Tenderness is present along the posterior and posteromedial aspects of the olecranon tip during forced extension. A flexion contracture may be present.
If conservative treatment fails arthroscopic excision of osteophytes may be necessary.

Little leaguers' elbow
This is a fracture of the medial epicondylar physis.
Point tenderness is present over the medial epicondyle and a flexion contracture may be present.
XR may show widening or fragmentation of the epicondylar physis.
Treatment depends on the stability of the fragment, which is assessed on stress XR. If there is any instability the fragment needs to be openly fixed.

Javelin throwers' elbow
An overhead throwing action may lead to avulsion of the tip of the olecranon; a round arm action leads to avulsion of the medial epicondyle.

Osteochondritis dissecans and Panner's disease
Overuse injuries of the radiocapitellar joint include osteochondritis – Panner's disease; and OCD.
Panner's disease occurs in children age 4-8 years and involves the entire ossific nucleus of the capitellum. It occurs almost exclusively in boys. The disease is often self limiting and conservative treatment leads to reossification and resolution of symptoms with time.
OCD occurs in patients 10 years or older involved in throwing, weight lifting and gymnastics. It involves a portion of the capitellum and often leads to permanent deformity of the joint.
MRI in OCD shows low signal intensity on T1 and T2 images early; later MRI may show increase in T2 signal consistent with separation or detachment of a fragment.
Treatment for lesions with intact cartilage is conservative; for partially or completely detached fragments arthroscopic debridement is necessary, or fixation if large enough.

<< Back to Resource List
 
 
© NEWSEC :: Phone: (02) 4323 2683