Sprengel Deformity - Pathogenesis, Causes, Symptoms, and Diagnosis

Introduction:

Sprengel deformity, also referred to as Sprengel shoulder deformity, is a condition that is present from birth. This condition is often accompanied by thinning or weakening of the muscle mass. This results in functional disabilities and disfigurement of the shoulder. This condition usually requires surgical correction of the deformity. This article will discuss Sprengel deformity, its pathogenesis, causes, symptoms, and treatment in detail.

What Is Sprengel Deformity?

Sprengel deformity affects the shoulder girdle of the affected individuals, which includes the scapula (shoulder blade) and clavicle (collarbone). This deformity is characterized by an elevated shoulder blade on one or both sides. It occurs due to a malformation of the shoulder during embryonic development. The Sprengel deformity causes cosmetic deformity and functional limitations of the shoulder.

What Is the Pathogenesis of Sprengel Deformity?

During embryogenesis, the shoulder blade develops along with the upper limb during the fifth week of gestation along the upper cervical region with the arm bud. By the twelfth week of gestation, It migrates to its last anatomical position near the second to the eighth backbone.

• Failure in the migration of the shoulder blade during embryonic development results in protrusion of them in the neck.

• The horizontal diameter of the deformed shoulder blade is more than the vertical diameter of the shoulder blade.

• The affected shoulder is unusually connected to the backbone and involves the movement of the shoulder blade. Sometimes this results in ossification, which causes the hardening of the structure (omovertebral bone).

• The surrounding musculature is also affected, resulting in weakening and muscle wastage.

• The shoulder girdle muscles, such as the trapezius, sternocleidomastoid, latissimus dorsi, rhomboids, and levator scapulae, are often poorly developed and sometimes absent.

What Are the Causes of Sprengel Deformity?

The Sprengel deformity is a developmental anomaly caused due to failure in the migration of the shoulder blade to its original position during embryonic development. Sometimes it can result from a genetic defect caused by harmful changes or alterations in the DNA (deoxyribonucleic acid) material. It is inherited in an autosomal dominant pattern.

They also occur in association with other syndromes, such as:

• Iniencephaly (an uncommon neural tube defect that is characterized by occipital bone defect, incomplete closure of the spine, and backward bending of the head).

• Fused ribcage (abnormal fusion of bones in the chest called the ribcage).

• Cleft palate (an abnormal opening in the roof of the palate).

• Cervical ribs (an additional rib formed above the first rib).

• Kilppel-Feil syndrome (a rare condition that causes abnormal fusion of vertebral bones in the neck region).

• Omovertebral connection (an abnormal fibrous or osseous connection of shoulder blade and backbone).

How Common Is Sprengel Deformity?

Most literature reports that females are more likely to get affected by Sprengel deformity. However, other reports show it is common in males and females. They are often seen in association with other disorders or syndromes.

What Are the Symptoms of Sprengel Deformity?

In most cases, the shoulder deformity occurs unilaterally and rarely occurs bilaterally. The severity of symptoms differs for each individual. The affected individual has one shoulder higher and elevated than the other. Cavendish classifies the appearance of the Sprengel shoulder deformity into four grades.

• Grade 1 (Very Mild): The shoulder levels are flat in level, and the deformity is invisible when dressed.

• Grade 2 (Mild): The shoulder level is almost in the plane. A visible lump is noticed when the patient is dressed.

• Grade 3 (Moderate): The shoulder level is elevated by two to three centimeters. The deformity is visible.

• Grade 4 (Severe): Shoulder level is elevated. The superior angle of the shoulder blade lies near the back of the head.

Other symptoms of the Sprengel deformity are:

• Restricted arm movements.

• Limitations of shoulder movements.

• Deformities of the neck range from torticollis (twisting or tilting of the cervical spine) to severe backbone deformity.

• Some cases show a webbed neck.

• Scoliosis (abnormal sideways curvature of the backbone).

• Abnormalities of the collar bone.

• Underdeveloped shoulder and neck muscles.

How Is Sprengel Deformity Diagnosed?

The diagnosis of Sprengel deformity is based on the thorough physical examination of the patient. The doctor may perform various other specialized tests to assess the symptoms. The effective investigation method is the radiographic examination of the shoulder.

• Imaging studies such as plain radiography along the anteroposterior view are used in visualizing the rotated and elevated shoulder blade.

• Other imaging studies, such as Magnetic resonance imaging (MRI) and Computed Tomography (CT), are used to confirm the diagnosis.

The radiographic findings of the frontal view of the affected individuals with Sprengel deformity are classified by Rigault into three grades. It is based on the relationship between the superomedial angle (SM) (above and toward the midline) and the vertebral column.

• Grade 1: SM angle lower than the second thoracic vertebrae but above the transverse process (bony projection along both sides of vertebrae) of the fourth thoracic vertebrae.

• Grade 2: SM angle between the fifth cervical vertebrae and the transverse process of the second thoracic vertebrae.

• Grade 3: SM angle above the transverse process of the fifth cervical vertebrae.

What Are the Treatment Options for Sprengel Deformity?

The most effective treatment option is the surgical management of shoulder deformity.

• The patients are referred for surgical management based on their age, severity of the condition, and associated conditions.

• Patients with deformities on both sides and grade 1 of the Cavendish classification are kept under observation and advised for treatment only when they have functional disabilities.

• Surgical management is generally avoided in patients with grade 4 deformity, short neck, surrounding muscle, and structural deformity.

• Affected patients between the ages of two to five have better prognoses with surgical management.

• There are various surgical techniques for treating Sprengel deformity; however, the more commonly performed procedures are the Woodward and Green scapuloplasty.

• The surgical procedure involves; surgical displacement of the origin or insertion of the scapular muscles, surgical removal of the superomedial border of the shoulder blade, and removal of omovertebral bone.

Conclusion:

Sprengel deformity, or the high scapula, is a rare congenital deformity affecting the shoulder girdle. They are sometimes associated with other conditions or syndromes. Defects in the surrounding muscles and structures accompany them. This results in functional limitations and cosmetic deformity of the shoulder. Plain radiography is the commonly performed investigation method. Surgical intervention is the ideal treatment option, especially between the ages of three to five. Post-operatively, the affected child is referred to a physical therapist to improve the range of motion in the shoulder.