Osteoarthritis of the hip joint (coxarthrosis)

Coxarthrosis - osteoarthritis of the hip joint. Most often, the pathological process develops in the upper pole of the hip joint with upper lateral displacement of the femoral head (about 60% of patients with coxarthrosis, men suffer more often than women). Less common is a lesion of the medial pole of the joint with a medial displacement of the femoral head and protrusion of the acetabulum (about 25% of patients with coxarthrosis, women suffer more often than men). Concentric lesion, in which the entire joint is affected, is the most rarely encountered coxarthrosis (about 15% of patients with coxarthrosis, women suffer more often than men). It is extremely rare that there is a lesion in the back part of the joint, which can only be detected on the X-ray in the lateral projection.

[1], [2], [3], [4], [5]

What causes coxarthrosis?

Coxarthrosis usually affects people between the ages of 40-60. The main predisposing factors to the development of osteoarthritis of the hip joint are its congenital dysplasia, Perthes disease, anomalies of the length of the lower limb, acetabular dysplasia. Unilateral coxarthrosis is much more common than bilateral.

What are the symptoms of coxarthrosis?

Coxarthrosis has the main symptom - pain when walking and resting on the leg in the thigh, buttock, groin, sometimes only in the knee joint, which makes diagnosis much more difficult. Patients are concerned about stiffness in the affected joint after a period of rest; a painful decrease in the range of motion, with the volume of the inner and then outer rotation and the leg abduction angle being reduced first. The functional ability of the patient decreases: it is difficult to bend over, put on socks, shoes, lift anything from the floor. In the most severe cases, you can hear (but not palpable) crepitations during movements in the joint. Soreness over the lateral surface of the joint may be due to secondary trochanteric bursitis. In the later stages, coxarthrosis is characterized by the appearance of lameness due to shortening of the leg due to the migration of the femoral head, and in bilateral lesions - the “duck walk”. Atrophy of the muscles of the thigh and buttocks develops, characteristic “antalgic” (coxalgic) gait and the so-called Trendelenburg sign appear: when the patient tries to lean on the affected limb, the pelvis descends.

Coxarthrosis is the most severe form of osteoarthritis. The course of the disease is chronic and progressive. The rate of disease progression varies. In most cases, patients who need surgical treatment, have a relatively short history - from 3 to 36 months. With a rapidly progressing course of coxarthrosis, the patient’s complete disability occurs over several years, especially with bilateral lesions. According to LG Danielsson (1964), in some of the patients examined, the condition remained stable for 10 years or more. Coxarthrosis with a concentric lesion of the hip joint and hypertrophic variant has a more favorable prognosis. For coxarthrosis, cases of spontaneous reverse progression of the disease are described in case surgical treatment was delayed.

Most often coxarthrosis is complicated by the destruction of bone tissue. Other complications of coxarthrosis include aseptic necrosis of the femoral head, protrusion of the acetabulum, destruction of cysts of the acetabulum. In some cases, rapidly progressing coxarthrosis can lead to an unusual pattern - pronounced destruction of bone tissue and a wide articular gap. This variant of coxarthrosis is called the “analgesic hip joint,” because it is associated with the use of painkillers. However, it can develop in patients who do not take it at all or take little analgesics and NSAIDs.

Coxarthrosis may occur secondarily against the background of contralateral or ipsilateral gonarthrosis. Among the complications of the periarticular structures, trochanteric bursitis most often develops.

Coxarthrosis: species

Coxarthrosis is radiologically divided into two types: hypertrophic coxarthrosis, in which signs of an increased reparative response (osteophytes, subchondral sclerosis) predominate, and atrophic coxarthrosis, in which signs of an increased reparative response are not expressed. Some authors describe a particular form of rapidly progressive coxarthrosis, in which the narrowing of the joint space occurs within a few months.

A study of joint biomechanics has demonstrated that the load on the hip joint consists of the load of body weight and the forces that cause the thigh. The upper pole of the joint is the zone through which the load axis of the body mass passes, therefore the upper pole is the most vulnerable area.

According to some data (54 patients with coxarthrosis and 40 people without pathology on the part of the musculoskeletal system were examined, the groups were comparable in age and sex), a decrease in the range of motion in the hip joint was associated with the severity of the clinical and X-ray stage of the disease. However, not all types of movements were associated with the progression of coxarthrosis; for example, the greatest correlation was noted for flexion (r = -0.84), abduction and internal rotation of the thigh (r = -0.69 and r = -0.67, respectively), weaker correlation - for external rotation (r = -0.40); no correlative relationship was found for the cast.

Consequently, a decrease in the range of motion in the hip joint (flexion, abduction and internal rotation of the hip) is strongly correlated with the severity of the X-ray stage of coxarthrosis.

In the late stages of coxarthrosis, significant changes in the synovial membrane and thickening of the articular capsule are found. A study of material obtained during hip arthroplasty suggests that coxarthrosis often has small areas of aseptic necrosis of the femoral head.

[6], [7]