Causes and classification
The disease remains not fully understood to this day. Currently, medicine considers three main theories for its origin:
- Mechanical: fetal development is disrupted due to external physical factors, such as oligohydramnios, polyhydramnios, or abnormal intrauterine position.
- Infectious: a pathogen (amniotic infection) penetrates the central nervous system of the embryo in the early stages—around the 4th–5th week of development.
- Hereditary: confirmed by documented cases of familial inheritance of the pathology.
Depending on the extent of tissue involved in the pathological process, arthrogryposis is divided into several forms. The most severe is generalized, affecting muscles and joints throughout the body, including the jaw, neck, and trunk. Other forms include involvement of all four limbs, isolated involvement (upper or lower limbs only), and involvement of a single segment.
Symptomatology and clinical paradoxes
The appearance of a child with the typical form of the pathology is very specific. Lesions most often affect the distal extremities (hands and feet), forming radial or ulnar clubhand and atypical clubfoot.
In upper limb involvement, the arms appear thin due to muscle atrophy, with shoulders pressed against the body and internally rotated. Elbows are usually fixed in extension, and hands are pressed against the forearms. Fingers are straight, thin, gathered together, and deviated, with the thumb often tucked beneath the others. Some patients develop a "claw hand" deformity (hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints).
A crucial feature of the disease is the clinical paradox. The functional capabilities of the patient are determined not by the angle of joint flexion/extension, but by the state of the muscle tissue:
- If contractures are massive but muscles are preserved, the patient will be able to move actively within the available range of motion.
- If muscles are profoundly hypoplastic, the patient remains completely helpless even with minimal contractures.
Features of lower limb involvement
The lower extremities are affected no less severely. Complex flexion-abduction-external rotation contractures form in the hip joints. These are often accompanied by hip dislocations. Unlike typical dysplasia, these dislocations are of embryonic origin and are fully formed by birth. Pronounced spinal hyperlordosis is also observed.
Flexion contractures predominate in the knee joints, though extension contractures also occur, up to and including subluxation of the tibia with hyperextension. The feet are almost always affected, developing rigid, treatment-resistant clubfoot.
诊断与治疗原则
Diagnosis is established based on the striking clinical picture immediately at birth. Radiography confirms joint dyscongruence and dysplasia, deformities, bone tissue atrophy, and osteoporosis.
Treatment of arthrogryposis is an extremely complex task, as deformities are highly resistant and rigid. Physicians aim to cover all affected areas with therapy as comprehensively as possible.
A comprehensive approach includes:
- The use of serial plaster casts to correct the wrist joints.
- Special orthopedic positioning devices (e.g., for shoulder abduction).
- Remedial gymnastics and general massage.
It is impossible to completely eliminate the consequences of the disease; the prognosis only allows for partial restoration of functions. The main goal of orthopedists is to restore the weight-bearing and static function of the lower limbs so the patient can stand and walk.
简述：主题相关问答
What pathomorphological tissue-level changes occur in muscles during arthrogryposis?
In arthrogryposis, hypoplasia of muscle tissue and pronounced muscle atrophy are observed.
What types of surgical interventions are used to correct contractures in arthrogryposis?
Various surgical interventions on the upper and lower extremities are used for the surgical correction of contractures and deformities in arthrogryposis. The list of main surgical methods includes:
- Shoulder arthrodesis — intervention on the shoulder joint.
- Elbow arthrolysis — operations on the elbow joint.
- Wrist arthrodesis — stabilization of the wrist joint.
- Derotational osteotomy — correction of the forearm bones.
- Soft tissue procedures — surgical interventions on the hand.
- Open reduction of the femoral head — operations on the hip joint.
- Corrective femoral osteotomies — interventions in the subtrochanteric and supracondylar regions.
- Knee arthrolysis — operations on the knee joint.
- Myotenoligamentotomy — interventions in the popliteal region.
- Corrective procedures — interventions on the feet.
To remember the typical arm posture in arthrogryposis, imagine a "doll with rusted joints": shoulders pressed, elbows non-flexing (straight), hands turned inward, and thin fingers angled to one side.
课堂与考试常见问题
What is more important for the motor activity prognosis: joint involvement severity or muscle status?
The state of the muscular system plays a decisive role. When muscles are preserved, active movements are possible even in the presence of severe joint contractures.
How does hip dislocation in arthrogryposis differ from typical congenital dislocation?
In arthrogryposis, dislocations occur in the early stages of intrauterine development (embryonic) and are fully formed by the time the child is born.
Can arthrogryposis be completely cured?
Unfortunately, deformities are extremely rigid due to profound changes in all tissues. Treatment allows only partial restoration of limb functions, focusing on the ability to independently bear weight on the legs.
该主题的其他拓展内容
- Features and differences of atypical clubfoot in arthrogryposis versus idiopathic clubfoot
- Radiological signs of joint dysplasia and dyscongruence
- Technique of serial casting for contractures
- Surgical treatment of embryonic hip dislocations
“骨科”板块的其他主题
本资料由 WhiteCoat Pro 讲师根据医学院校教学大纲编写。仅供教育参考。