pathology: rotator cuff insertional tendinopathy

yogabook / pathology / rotator cuff insertional tendinopathy

Definition of

Insertional tendinopathies of the rotator cuff are thought to affect 30% of the population and may be the most common cause of shoulder pain. The affected tendons tend to rupture over a longer period of time. These are atraumatic in 50% of cases and are caused by pre-existing degeneration, where inadequate trauma is sufficient to trigger the rupture. From the age of 50, the incidence of ruptures increases significantly; by the age of 80, the incidence of partial or complete ruptures is already 80%. However, the radiologically detectable ruptures are very loosely related to the observed symptoms.
In younger people, degeneration-related ruptures are naturally not to be expected, but avulsions rather than tendon ruptures often occur even with adequate trauma. The cranial pole of the greater tuberosity is frequently affected. Ruptures are also frequently (63%) detectable with initial dislocation of the shoulder joint and are presumably predisposing.
It is not uncommon for initial damage to become apparent from the age of 40, usually affecting the supraspinatus and less frequently the infraspinatus. From the age of 70, all 4 muscles are usually affected, with ruptures occurring in 26% of cases, compared with 5% up to the age of 50.

This disorder affects the quality of life through functional limitations, restricted ROM, especially in the direction of exorotation and abduction, as well as restricted ability to perform overhead activities, and of course associated pain, which often projects to the area of the greater tuberosity and the attachment area of the deltoid.
The pain often creeps in, is sometimes intermittent and cannot necessarily be clearly localised; often only the painful arc triggers the pain. Atrophy of the supraspinatus and infraspinatus or biceps tendinitis is often already present.

Passive mobility of the shoulder joint is usually not impaired, but active pain hinders utilisation of the ROM. Palpation reveals crepitations, particularly when the arm is rotated, and the tendon may also snap. A painful arc is often present, as strength deficits in the rotator cuff predispose to external impingement due to humeral elevation. There is also often a noticeable strength deficit, especially with lateral flexion and exorotation. Pure tendopathy does not necessarily involve a strength deficit.

Insertional tendopathies and partial ruptures

Underlying rotator lesions are tendopathies such as tendinitis, tendinosis, paratendinosis and partial tears. Extrinsic pathomechanisms include wear of the tendon by the neighbouring bone structure such as the humeral head or the acromion based on muscular fatigue, weakness, pain and inadequate muscle performance. Half of those affected suffer from a reduced subacromial space and are therefore predisposed to external impingement. The intrinsic factors include

The more frequent occurrence in the dominant arm when used in sport and work indicates excessive strain on the tissues as the cause. Here too, ultrasound proves to be very helpful, followed by MRI. Medical history and physical examination with clinical testing are very important. They also indicate the possible need for further investigations.

The supraspinatus plays a special role in rotator cuff injuries. Its tendon covers the humeral head from the cranial side and has a non-vascularised area near the greater tuberosity, which makes it particularly susceptible. Furthermore, the tendon is all too easily trapped in the coracoacromial arch consisting of the acromion, acromioclavicular joint, coracoid process and coracoacromial ligament. If an inflammatory reaction is necessary to repair the tendons (phase 1 of tendon healing), this takes up additional space due to the oedema that develops in the tendon, of which there is already little in the subacriomial space. The resulting deterioration in the supply situation at the base of an existing disorder predisposes to tears and ruptures. Degenerative damage, on the other hand, is more common in non-athletic people over the age of 40. This often results in fibrosing subacromial bursitis, which consumes further space.
Insertional tendopathies can cause subacromial impingement with pain in the range of 60-120° frontal abduction or 60-120° lateral abduction. Overuse-related damage can be accompanied by acute trauma, so that inadequate trauma leads to a rupture.

Surgery is performed primarily on young, physically active patients, preferably within a few weeks of the triggering event, as the prognosis after surgery deteriorates over time. The following factors tend to speak in favour of conservative therapy:

  • older age (from 65)
  • Less physical activity
  • Minor pain or absence of pain
  • degenerative genesis
  • gradual onset
  • Lack of patient compliance
  • Frozen shoulder as a comorbidity
  • Concomitant diseases: Diabetes mellitus, RA, prolonged cortisone therapy, osteoporosis

Partial ruptures are generally treated conservatively. After initial rest and, if necessary, drug therapy with analgesics and anti-inflammatory drugs, pain-free active exercises for all unaffected muscles are started from week 4 onwards. 2 weeks later, the affected tendon can be trained with the weight of the limb, a further 3 weeks later progressively with resistance. Sports that put strain on the shoulder are suspended for six months. Comorbid or co-causing scapular dyskinesia must also be treated. The PT to be performed is similar to that for impingement, but the affected tendon is omitted here. If the posterior capsule is thickened and contracted and a GIRD is present, this must also be treated. If mobility deficits and flexibility restrictions of the capsule are also treated, this is superior to strengthening monotherapy. Arthroscopy can only be indicated after 6 months of unsuccessful conservative therapy.

A partial rupture may also be associated with a pulley lesion, which in 3/4 of cases is due to isolated ruptures of the glenohumeral ligament, but in 1/4 of cases rotators are also defective .

Complete rupture

Complete ruptures are definitely associated with partial loss of function of the shoulder joint if they affect the teres minor or the subscapularis. Even isolated complete ruptures of the subscapularis tendon contraindicate conservative therapy.
If the rotatory ligament system of subscapularis and infraspinatus is still intact and the genesis is degenerative, the patient is older and has rather low demands on function and resilience, conservative treatment can be considered (3-6 months). If frontal abduction and lateral abduction are still available to a limited extent and the ability to exorotate is given, conservative treatment is clearly recommended (no less than 6 months). However, complete ruptures predispose to omarthrosis, even if they are functionally well compensated. In any case, regardless of the chosen form of therapy, restrictions in strength and strength endurance during overhead activities are to be expected. If a frozen shoulder (adhesive capsulitis, periarthropathia humeroscapularis) is also present, treatment of the complete rupture must wait until the movement restriction of the frozen shoulder has largely subsided (i.e. towards the end of phase 3).

Complete rupture of the subscapularis

A complete rupture of the subscapularis cannot be functionally compensated for conservatively, which is why several surgical procedures are available in which parts of other muscles are used, including the pectoralis major and deltoid pars clavicularis. Biomechanically, the transfer of the cranial parts of the pectoralis major more profound than the coracobrachialis and short biceps shows the best results.

Complete rupture of the infraspinatus

In the case of an infraspinatus tendon tear that cannot be repaired surgically, part of the latissimus dorsi can be used.

Multiple complete rupture

If there is a compensated rupture of the infraspinatus and subscapularis and the supraspinatus tendon is also torn, this can often no longer be treated arthroscopically, but only openly.

The aim of the surgery is to largely restore function and resilience, especially of the subscapularis and infraspinatus ligament system. The treatment is similar to that for external impingement.
Conditions for cancelling conservative therapy are

  • an occurring drop arm sign
  • Persistent pain at the same level after 6 weeks
  • Functional deterioration after initial improvement

The necessary rehabilitation after surgery follows a complex individualised protocol.

Cause

  1. traumatic (50%)
  2. degenerative, especially in older non-athletes, partly due to inadequate trauma (50%)

Predisposing

  1. Age
  2. genetic
  3. Altered biomechanics such as scapular dyskinesia
  4. vascular changes
  5. inflammatory processes

Diagnosis

  1. Sono
  2. MRI
  3. clinical tests

Symptoms

  1. restricted ROM
  2. Reduction in strength, especially in the direction of lateral bending and exorotation
  3. Limited ability to perform overhead activities
  4. Movement-dependent pain, partly projected into the area of the greater tuberosity and the attachment area of the deltoid muscle
  5. Frequent: Painful arc due to external impingement
  6. Divergence of passive and active mobility
  7. possibly crepitations or snapping tendons

Therapy

  1. Surgery for younger patients or functionally non-compensable complete ruptures
  2. Conservative in the presence of corresponding negative factors (see above)

Complications

  1. Complete rupture
  2. Partial loss of function
  3. Omarthrosis

DD