Tendon injuries

Differential diagnosis: muscle injuries

The symptomatology of tendon injuries often overlaps with injuries to the muscle bellies themselves.

For example, in a rupture of the biceps brachii muscle (due to forced loading or a direct blow to a tensed muscle), the patient hears a snap and feels acute pain similar to a tendon rupture, although less pronounced. A hematoma and local tenderness form at the injury site.

• An important distinguishing feature: palpation along the course of the tendons remains painless, and pain increases only upon tension of the muscle itself.
• In a partial rupture of the biceps muscle, the tension of the tendon can be felt during its contraction.

Another example is a plantaris muscle rupture. The main complaint is deep, aching pain in the leg, increasing with walking. Treatment here is conservative: physical therapy (PT), analgesics, and mandatory offloading (wearing shoes with a stable high heel is used).

A special place is occupied by muscle hernia — a pathology that occurs with partial muscle damage and concomitant complete rupture of the fascia covering it.

• Most often localized on the lateral surface of the thigh and lower leg.
• The formation has an elastic consistency.
• Specific symptom: the hernia increases when the muscle is relaxed, and decreases (disappears) when it is tensed. Palpation reveals a fascial defect ("herniated ring").

Classification of tendon injuries

In relation to the external environment, injuries to the tendinous apparatus are divided into two large groups:

1. Open injuries. Accompanied by a breach of the integrity of the skin. As a rule, these are the result of chop or stab wounds. A characteristic feature of open injuries is that they are very frequently combined with damage to adjacent blood vessels, nerve trunks, and bones.
2. Closed (subcutaneous) injuries. The skin remains intact. In clinical practice, such ruptures are most typical for extensor tendons. The main mechanism of injury is either a sharp, sudden muscle contraction or a strong blow with a blunt object to the limb.

Clinical presentation and diagnostic principles

In a complete rupture of a tendon, a characteristic displacement of its proximal end (the part connected to the muscle belly) occurs. Due to the muscle pull, it "slips away" along its course. If surgical intervention is delayed, a cicatricial thickening eventually forms on this torn end. Subsequently, this thickening often becomes adherent to the surrounding tendon sheath, which makes the operation more complex.

The general diagnostic algorithm for such injuries is similar to that for muscle injuries:

• Clinically: the physician identifies a gross functional impairment of the corresponding muscle and a visible deformation in the injury zone.
• Instrumentally: ultrasound examination (US) or magnetic resonance imaging (MRI) is used to accurately assess the defect, the degree of displacement, and the state of the surrounding tissues.

Surgical treatment and tendon repair

The tactics of muscle function restoration directly depend on the localization of the injury, the exact level of damage, and the time that has elapsed since the rupture.

Main surgical options:

• Suturing the ruptured ends of the tendon (the most frequent and demanded method).
• Tendon reconstruction (tendoplasty).
• Suturing the tendon end directly to the bone (at the former anatomical attachment site or a new point).

Surgeons pay special attention to the so-called "critical zone". This term refers to the area of the digital tendon sheaths of the hand. It is here that tendon suturing yields the poorest functional results due to the high risk of adhesion formation.

An ideal tendon suture should be simple to perform, securely hold the ends against separation, prevent fraying, not impede smooth gliding within the sheath, and, crucially, cause minimal disruption to the tissue blood supply.

Special sutures include intrastromal non-absorbable adapting sutures (e.g., where the suture material is almost entirely hidden within the tendon shaft).

• Cuneo's suture offers extremely high strength, but has a major drawback: it severely disrupts the blood supply, impairing regeneration.
• Rozov's suture is considered the least traumatic among the intrastromal options.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Conservative treatment of plantaris muscle rupture: physical therapy regimens
• Complications of muscle hernias: aseptic inflammation in the hernia ring
• Technique of Rozov's suture and its modern modifications
• Proximal blocking sutures and tendon transfixation
• Method of removing pull-out tendon sutures

Other topics in the "Specialized Adult Traumatology" section

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