Ankylosis of the hip joint.

The extreme degree of disruption of the statodynamic function of the hip joint in the form of its complete immobility is defined by physicians as ankylosis of the hip joint (ankylos means curved in Greek).

Epidemiology

According to some clinical data, the prevalence of hip joint damage in ankylosing spondylitis reaches 24-36%. Hip replacement surgery is required in more than 5% of patients with this disease.

Causes of the ankylosis of the hip joint.

Ankylosis is a specific lesion of the joints, the causes of which are associated with a number of destructive processes occurring in the joint and affecting the articulating bone surfaces in it in case of trauma (fractures, dislocations and/or subluxations of the femoral head), as well as due to inflammatory and degenerative changes in joint diseases of various etiologies.

Loss of mobility can be iatrogenic: after fixation of the joint during arthrodesis, osteosynthesis or as a result of prolonged immobilization with plastering. [1]

Risk factors

In orthopedics, the major risk factors for the development of hip ankylosis include patients having:

• coxatrosis or hip osteoarthritis, especially dysplastic and deforming hip osteoarthritis;
• Ankylosing spondylitis or Bechterew's disease - with spread to the hip joint;
• Juvenile ankylosing spondylitis;
• Long-standing inflammation of the hip joint in rheumatoid arthritis, tuberculous and septic arthritis, tendinitis of the greater trochanter or hip bursitis;
• inflammation affecting the tendons of the hip joint in the area of their attachment to the femur - trochanteritis;
• Pelvic bone tuberculosis leading to ostitis;
• hip osteochondropathy - Legg-Calve-Perthes disease;
• Acetobular (acetabular) protrusion of the hip joint, often associated with trauma, osteoarthritis, osteomalacia, fibrous dysplasia, or deforming osteitis;
• lumbosacral arthritis and osteoarthritis;
• hemophilic osteoarthritis;
• Diffuse idiopathic skeletal hyperostosis.

Pathogenesis

Biomechanical dysfunction hip can result from the fusion of articulating bone structures - the subchondral trabecular (cancellous) bone tissue of the femoral head and the acetabulum of the pelvic bone. Such ankylosis is called bony ankylosis.

If immobilization of the joint parts occurs due to their pathological connection of articular and periarticular fibrous tissue - in the process of replacement of osteoblasts of damaged bone tissue by fibroblasts, ankylosis fibrosis is defined.

The pathogenesis of such spontaneous fusion/union of joint structures - with loss of both active and passive motion - is due to their morphological changes (in the above diseases), including bone destruction; osteophyte formation; alteration of epiphyseal cartilage tissues (with thinning); thickening of the synovial bag with hyperplasia of synovial membrane tissues, reduction of the joint cavity and overgrowth of the joint gap with fibrous tissue, which may ossify over time. [2]

Symptoms of the ankylosis of the hip joint.

The first signs of joint ankylosis are manifested by impaired mobility in the form of morning "stiffness" after prolonged standing in one position. With progressive changes in and around the hip joint in cases of bony ankylosis, symptoms such as pain when walking are usually absent. But in the so-called vicious position of the ankylosed hip joint - with a significant deviation of the limb from its functionally correct position - there is a dramatic change in gait and a severe limp. More serious problems with walking - up to its complete impossibility, leading to a wheelchair - occur if the ankylosis is bilateral.

Fibrous ankylosis of the hip joint causes intense arthralgia, and with any movement of the affected lower limb, the pain increases, radiating to adjacent joints.

Significant fibrous ankylosis limits the range of motion of the joint, such as flexion-extension rotations, movements along the frontal and sagittal axes. In addition, there is a marked shortening of the limb with the affected hip joint when standing on both legs. [3]

Complications and consequences

Partial or complete ankylosis of the hip joint adversely affects the biomechanics of other joints, including the contralateral hip and both knees, and increases stress on the lumbosacral spine.

This pathology causes weakening of the hip muscles, affects the state of the intervertebral discs and can even provoke curvature of the lumbar spine. [4]

Diagnostics of the ankylosis of the hip joint.

Joint diagnosis when ankylosis is suspected involves a complete examination of patients to identify the causes of hip dysfunction.

Appropriate blood tests (general, for rheumatoid factor, C-reactive protein, etc.) and synovial fluid analysis are taken.

Instrumental diagnostics include radiography, ultrasound and hip MRI.

Differential diagnosis

The differential diagnosis is made with contracture and stiffness (arthrogryposis) of the hip joint.

Treatment of the ankylosis of the hip joint.

Hip ankylosis is treated surgically. In cases of insignificant fibrous fusion, excision is used.

Surgical treatment for bony and severe fibrous ankylosis may be performed using corrective joint osteotomy, arthroplasty, or arthrodesis.

In order to provide more complete joint functionality and improve the quality of life of patients, a very complex operation with complete replacement of the joint surface with a biocompatible construction is performed - total hip replacement.

And to relieve the pain of fibrous ankylosis, physiotherapy treatment is carried out using various methods, for more information see. - Physiotherapy for joint diseases [5]

Prevention

Prevention of ankylosis - timely detection and proper treatment of inflammatory and destructive-dystrophic diseases of the hip joints, as well as prevention of their injuries.

Forecast

In hip ankylosis without surgical intervention, the prognosis is reduced to inevitable disability. If arthroplasty is performed, joint function is partially restored (although recurrence of pathology is not excluded); arthrodesis only slightly improves joint mobility, but successful endoprosthetics can restore mobility with the ability to walk without any orthopedic mobility devices.