The tendons are part of the musculoskeletal system, constituting the union of the muscle with the bone, allowing the mobilization of the muscle contraction. The transition zone between the muscle and the tendon is called the myotendinous junction zone.
The tendons are fibrous structures, pearly white, and strong, to allow the transmission of the contractile force of the muscle to the bone, and thus mobilize it.
The tendon is formed by fibers oriented in the same direction and surrounded by connective tissue constituting the endothenon, which facilitates movement. These fascicles in turn are surrounded as a whole by another layer of connective tissue constituting the epitenon. The next wrap of which they are is the paratenon, which in the areas of union of the tendon to the bone is reinforced by a resistant fibrous sheath, called peritenon, and in areas subject to great tension appear the pulleys that are reinforcements of the wraps that just like mechanical pulleys favor the change of the direction of the forces increasing muscular power. In summary the tendons are like strings formed by different layers in order to increase the resistance of this and promote movement.
The degree of elasticity of the tendon depends on the force applied and the position of the tendon at the moment of the beginning of the movement. In addition, the patient’s age, previous training and other factors related to the patient’s general condition influence tendon resistance.
Depending on the duration:
Acute: those that occur suddenly and after the application of an intense force.
Subacute / Chronic: those that occur progressively and in which there is usually a previous deterioration of tendon fibers. Subacute lesions are those that remain over time, although in a limited way, and chronicles if they remain beyond three weeks, so in many cases both terms overlap.
-Tendinitis: The clinic presents as localized pain in the course of a tendon, usually of inflammatory cause with a traumatic antecedent either direct (contusion) or indirect (overexertion of the muscle group) accompanied by a certain degree of functional impotence.
-Tendinosis: This term encompasses a marked tendonitis in time, in which pain and inflammatory signs cease, but the degree of functional impotence continues. In most cases, a local thickening will be felt. In short, tendinosis, rather than a group of symptoms, refers to a deterioration of the fibers that make up the tendon; usually due to prolonged tendinitis over time or to repetitive tendonitis.
Both frames are produced mainly by a mechanical overload, punctual or repetitive microtrauma, although there are other causes such as increased intensity or frequency of overexertion, error in training technique or malposition during the same. The degree of injury is related to the base pathology of the tendon.
If the inflammation corresponds to the structure that contains the tendon, we speak of paratendinitis or synovitis, being its diagnosis and treatment very similar.
Depending on the production mechanism:
Among the acute injuries we can distinguish the injuries due to direct trauma or indirect trauma.
Direct trauma: They occur after a wound or contusion, which produces section of it, total or partial, which will be accompanied by functional impotence or inability to move depending on the degree of injury, and in all cases significant pain. More frequent in upper limb.
Indirect trauma: They are produced by excessive traction on it or by repeated tractions of great intensity, which can break or lacerate. These lesions are more frequent in the myotendinous junction, and in most cases, we must suspect that there is a previous degeneration of the same.
The diagnosis is based mainly on the clinical history and the exploration of the area, checking painful points and functional capacity, or, in case of tendinous sections, proceed to the examination of the wound.
In cases of breaks without trauma, sometimes, you can resort to the ultrasound of the area to corroborate the clinic.
It varies according to the production mechanism.
The involvement of the tendon in a wound necessitates its repair by suture, followed by immobilization several weeks to allow its total repair. The type of suture and the time of immobilization vary depending on the injured tendon.
Atraumatic rupture (overexertion or spontaneous rupture):
This picture is presented in tendons with some degree of previous degeneration, so, the healing will be somewhat defective, and may end up producing some limitation of the strength in the area.
The main treatment in these cases is immobilization, allowing the tendon to heal on its own.
Surgical intervention for suturing in these cases is very limited, at young ages or great physical activity, since the results obtained with it are unsatisfactory due to the base pathology of the tendon.
Tendinitis, paratendinitis or tendinosis:
The initial treatment is based on local cold, rest of the area and anti-inflammatory therapy, followed by functional reeducation of the affected area.
In cases of prolonged pain and time, local infiltration of corticosteroids may be performed, depending on the case, to reduce pain and inflammation, although the results are quite controversial.