[Spontaneous tendon ruptures. Etiology, pathogenesis and therapy].

Spontaneous tendon ruptures are ascribed to recurrent microtrauma resulting from continuous mechanical loading in a critical zone, to muscular imbalance combined with poor coordination as a result of inappropriate training, and also to deteriorating circulation with increasing age. Ruptures of the rotator cuff occur more frequently with increasing age, and the size of the rupture also correlates with age. The frequency of the complaint in men, the predominant involvement of the dominant shoulder, and also the above-average occurrence in occupations involving strenuous physical work indicate that degenerative change plays a role. In about 50% of patients presenting with a ruptured rotator cuff, the genesis is clearly traumatic. A trauma will almost always be the cause of an isolated rupture of the subscapularis tendon. The choice of reconstruction technique for a ruptured rotator cuff depends on the patient's age and level of activity in daily life. In the case of young patients, further surgical measures to repair the defect are indicated following failure of primary suture of the tendon, but in older patients subacromial debridement alone is considered the appropriate procedure. Rupture of the long head of the biceps tendon is usually a sequela of a rotator cuff rupture and the resulting loss of protective cover. Isolated ruptures of the long head of the biceps tendon are much rarer. They tend to occur in middle-aged patients and are usually the result of a relatively minor trauma. Ruptures of the distal biceps tendon are also relatively rare (3%) and are always of traumatic origin. There is no absolute indication for surgical intervention for a ruptured long head of the biceps tendon. Surgical repair is essential in the case of rupture of the distal biceps tendon. Transosseous reinsertion at the tuberosity of the radius is the recommended method of repair. Today's frequent cases of rupture of the Achilles tendon in the framework of sports activities are ascribed to inappropriate training procedures in combination with poor muscular coordination. An exogenous cause is the administration of local injections for pain relief in the form of a so-called tendon anesthetic. Today an increasingly important role is assigned to functional therapy with ultrasound support, although suturing the tendon is still the intervention of choice to meet the high functional demands imposed in the framework of top-level sports.(ABSTRACT TRUNCATED AT 400 WORDS)