Compensatory and adaptive mechanisms in children with congenital multiple arthrogryposis in the absence of active flexion in the elbow joint

Arthrogryposis is one of the most severe congenital orthopedic diseases, characterized by multiple joint contractures, hypoplasia or aplasia of the skeletal muscles of the extremities, as well as severe motor disorders. The use of compensatory strategies allows patients to improve the ability to self-care. OBJECTIVE To study the compensatory strategies in children with arthrogryposis with absent of active flexion in the elbow joint and estimate their dynamic after surgical treatment. MATERIAL AND METHODS We performed a clinical examination of 236 patients with arthrogryposis with deformities of the upper extremities due to arthrogryposis at the age of 10 months to 16 years. The examination was carried out before the operation, as well as at various times (from 1 month to 8 years) after. In 87 cases (67 patients), restoration of active elbow flexion was performed by transposition of latissimus dorsii or pectoralis major to the biceps position. The activity of the muscles involved that most commonly used in compensatory strategies (synergy of m. biceps brachii and m. deltoideus or m.biceps brachii and m. quadriceps femoris) in 10 patients (from 3 to 10 y.o.), was evaluated before and after (from 2 months to 2 years) surgery by surface electromyography. RESULTS It was found that children's compensatory strategies are formed at the age of 6 months to 1 y.o.6 months after surgery, the using of compensatory strategies becomes more rare, and 12-18 months after surgery, when the strength of the forearm muscles was 4 points, they were not used at all. CONCLUSIONS Compensatory strategies in children with the absence of active and preservation of passive flexion in the elbow joint are diverse. They depend on the amplitude of passive and active movements in the shoulder, the function of the hand and deformities of the lower extremities. These strategies in children with arthrogryposis are unstable and completely disappear when active movements in the elbow joint are restored in the functional range.