Patella displacement: symptoms, treatment methods, prognosis

Sports injuries

2K 1 20.04.2019 (last revised: 20.04.2019)

The patella (patella, patella) is a wide bone plate located inside the joint and designed to protect the cartilage. Represents the sesamoid bone - a bone formation inside the tendon fibers of the quadriceps of the thigh. The inside of the patella is covered with a layer of smooth, slippery cartilage that allows the condyles to move freely. Patellar displacement is a rare pathology caused by traumatic injury to the knee joint or caused by chronic diseases of the human musculoskeletal system. It implies a change in the position of structural elements relative to each other while maintaining their integrity.

Displacement classification

Pathological changes in the position of the patella based on pathogenetic factors can be:

• habitual - with a regular change in the position of the patella, accompanied by a pronounced painful symptom complex;
• partial - with an unstable position of the patella, prone to displacement with minor effects on the knee joint;
• congenital - due to joint injuries sustained at birth.

Depending on the scale, the displacement is classified into:

• partial - provoked by a sharp turn of the leg;
• full - represents a dislocation of the patella with displacement forward or backward due to a strong impact.

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Factors in the development of pathology

Displacement of the patella can be caused by:

• injuries (bumps and falls);
• high loads (weightlifting or triathlon);
• damage to the menisci, tendons and ligaments, increasing the vulnerability of the patella;
• hypotrophy of the muscles of the legs (quadriceps of the thigh) due to a sedentary lifestyle;
• anomalies in the development of the legs, including their deformity in the X-shaped type;
• dysplasia of the femoral condyles;
• abnormally high localization of the patella;
• knee tumors;
• chronic lesions of the knee joints (brucellosis), leading to their instability.

Trauma-induced dislocation is usually accompanied by tears of the lateral ligaments. With torsional horizontal displacement, the tendon of the quadriceps with the ligamentous apparatus of the patella is damaged.

Congenital pathologies predisposing to the habitual displacement of the patella include:

• hallux valgus;
• patellar hypermobility;
• hyperextension of the lower leg;
• hypoplasia of the femur.

The horizontal and habitual patellar displacements described above are treated surgically, followed by a rehabilitation period of up to six months.

Typical symptoms of dislocation

Most often, the displacement occurs outward, extremely rarely - medially. Accordingly, lateral or medial hypertension is diagnosed. Clinical symptoms are determined by the stage of the disease:

1. There is a feeling of discomfort in the patella area. Perhaps its temporary displacement, accompanied by acute pain.
2. Deformity of the knee is determined by palpation. The pain is moderate. It occurs with mechanical stress on the knee area.
3. Deformation is determined visually. The pain is pronounced, the movements are constrained.

Common symptoms include:

• pain localized in different areas of the joint, depending on the topography of the injury;
• crunching or clicking feeling when moving;
• limitation of joint mobility;
• decreased sensitivity of the skin in the injured areas;
• change in the shape of the knee;
• hyperemia of the skin and periarticular edema.

A displaced patellar fracture is a serious complication. It is manifested by pronounced edema and hemarthrosis. The upper fragment of the patella as a result of reflex contraction of the quadriceps muscle is displaced upward, and the rapidly growing bruise goes down to the foot.

Congenital patellar displacement

Congenital dislocation is extremely rare. Usually directed outward. Can be single or double-sided. There are three degrees of the disease:

• complaints may be absent, the knee is abnormally mobile;
• there is instability when walking with the patella unfolding outward;
• there are periodic blockages that prevent flexion; the calyx is in an unnatural position with a pathological lateral deviation of the lower leg.

It becomes possible to diagnose congenital displacement of the patella after the little patient begins to walk. Therefore, early diagnosis of pathology is difficult.

Usually, conservative therapy is prescribed, aimed at strengthening the muscles and ligaments:

• electromyostimulation;
• massage;
• exercise therapy complex.

If congenital displacement becomes habitual, surgery is indicated.

Examination by an orthopedist, analyzes and diagnosis

Diagnosis is based on:

• typical patient complaints;
• anamnestic data indicating the fact and mechanism of injury;
• the results of an objective examination;
• data of instrumental research methods:
• radiography (both joints in a standing position in the lower anterior and lateral projections);
• Ultrasound (to verify soft tissue injuries);
• CT (can be done with a flexed joint)
• MRI (the most accurate method, allows you to identify damage to tendons and muscles);
• the results of biochemical studies indicating an inflammatory process in the joint area:
• examination of the joint fluid (articular puncture is done);
• biochemical and general blood tests.

Treatment methods

The classic treatment regimen for patellar displacement is:

1. reduction of the patella by a traumatologist;
2. local use of cold (in the first 48 hours);
3. if necessary, the use of anesthetics (Novocaine derivatives) and analgesics (Diclofenac);
4. immobilization of the damaged joint with rigid orthoses or a plaster cast (within 1 month, movement on crutches is allowed);
5. FZT (usually - UHF, magnetic and laser therapy, electrophoresis);
6. Exercise therapy and massage in order to gradually develop the damaged joint and strengthen the musculo-ligamentous apparatus.

Surgical treatment is indicated for:

• damage to soft tissues;
• lack of effect from conservative treatment.

The method of choice is arthroscopy - a minimally invasive approach using an arthroscope, under the control of which surgical procedures are performed.

Forecast

If untreated, the injury can be complicated by the following pathological changes in the joint:

• synovitis;
• arthritis;
• arthrosis;
• deformation;
• chronic instability.

Treatment and rehabilitation period take from six months to a year, depending on the presence of concomitant injuries. Rehabilitation activities are carried out under the supervision of a traumatologist. Supportive dressings can be used for prevention. At the end of the recovery period, spa treatment is recommended. The forecast is favorable. Usually after 6-9 months, efficiency is restored.

Watch the video: dislocated knee or patella (January 2025).