Deformed trunk

Introduction The deformity of the trunk is the crankshaft phenomenon. The crankshaft phenomenon refers to the phenomenon that the bones are not matured and the posterior spinal fusion is performed. The posterior spine is firmly fused and the spine continues to grow in front of the spine, thus the phenomenon of spinal deformity is aggravated. Loss, increased vertebral rotation, and increased rib bulge.

Cause

The crankshaft phenomenon is caused by the imbalance of the spine growth caused by partial osteophyte blockage in the growth center of the vertebral body after the strong spinal fusion of the posterior road, which causes the spinal deformity to progress.

an examination

Related inspection

Spinal MRI

The longitudinal growth behind the spine stops, and the growth of the anterior column of the spine continues, but the strong fusion at the back prevents the development of the lordosis, which eventually leads to aggravation of the deformity. Generally, the angle of coronal malformation is increased by 10° or more. The reason for the phenomenon is that the growth potential of the anterior and posterior vertebral column is asymmetric after the strong fusion of the posterior tract, and the severity is proportional to the number of growth centers and growth capacity in front of the fusion zone.

Differential diagnosis

Idiopathic scoliosis Although scoliosis is a lateral curvature of the spine, scoliosis is usually accompanied by rotation and produces a typical paravertebral rib hump. The rotation of the torso, the vertebral ribs and the bulging of the lateral paravertebral muscles are visible deformities of the scoliosis. The Adam flexion test is often used to screen for paravertebral deformities of scoliosis. The method is as follows: the patient faces the examiner, and the patient bends forward until the trunk is parallel to the horizontal plane to see if the back is symmetrical. One side of the ridge indicates the rib and vertebral rotation deformity. .

The longitudinal growth behind the spine stops, and the growth of the anterior column of the spine continues, but the strong fusion at the back prevents the development of the lordosis, which eventually leads to aggravation of the deformity. Generally, the angle of the coronal malformation is increased by 10° or more. The reason for this phenomenon is that the growth potential of the front and rear of the spine is asymmetrical after the strong fusion of the posterior tract, and its severity is directly proportional to the number of growth centers and growth capacity in front of the fusion zone.

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