Spondylometaphyseal Dysplasia - Causes, Symptoms, Diagnosis, and Treatment

Introduction

In 1967, Kozlowski et al. first identified spondylometaphyseal dysplasia (SMD), which they classified as a rare new kind of bone dysplasia characterized by several forms of chondrodystrophy and generalized platyspondyly of varied degrees in the spine. It results in a wide range of phenotypic abnormalities and is genotypically autosomal dominant. The most prevalent type of SMD is Kozlowski-type SMD, sometimes called type 1 SMD. Kozlowski-type spondylometaphyseal dysplasia is brought on by genetic abnormalities in the TRPV4 gene. It is autosomal dominant in inheritance.

What Does Spondylometaphyseal Dysplasia Mean?

• A bone condition known as spondylometaphyseal dysplasia, Kozlowski type, affects the trunk and is characterized by short stature.

• Spondylo denotes the spine (vertebrae), metaphysis denotes the broad region of the bone containing the growth plate (the portion of the bone that develops throughout infancy), and dysplasia means abnormal development.

• Early infancy is typical when it first becomes apparent, along with poor development, uneven size, and a waddling walk with bow legs (genu varum).

• The early stages of osteoarthritis can affect the joints. Little hands and fingers, spine abnormalities, flared iliac wings (the widest region of the pelvic bone), and a flat, uneven hip bone are further indications and symptoms.

What Are the Causes of Spondylometaphyseal Dysplasia?

Kozlowski-type spondylometaphyseal dysplasia is a genetic disorder that indicates that one or more malfunctioning genes are to blame for its development. It is understood that the following gene or genes cause this illness through disease-causing variations or differences: TRPV4.

Knowing what genes are and how gene mutations influence the body can aid in the diagnosis and treatment of a genetic condition. The majority of genes have two copies in each person. The number of copies of a gene that must have a disease-causing variation determines how a disease is passed down through the family.

What Are the Clinical Symptoms of Spondylometaphyseal Dysplasia?

Different individuals with this condition may have different numbers and intensities of symptoms. Several bodily systems may be impacted by the symptoms of this illness.

1. Unusual vertebral column structure.

2. Delayed development of the epiphysis.

3. A kind of small stature that is disproportionate, with a short trunk and average-sized limbs.

4. A shortage or retardation of prenatal and postnatal growth.

5. A compressed vertebral body forms with closer spacing between the endplates.

6. A condition that affects the acetabulum, or hip bone socket, combined with the head of the femur, makes up the hip joint.

7. Endochondral ossification, a kind of replacement ossification in which bone tissue replaces cartilage, is a process that can go wrong.

8. A malformation of the ilium, the biggest and highest bone in the pelvis.

9. Very short digits in comparison to the hand or foot. Here, the term brachydactyly refers to several distinctive patterns of reduced digits (brachydactyly types A-E).

10. Underdevelopment of one or more carpal bones.

11. Widening of the ilium ala, or the iliac wing, in conjunction with external rotation, causes the iliac wing to look flared.

12. Any interference with the capacity to walk is referred to as a gait disturbance. In general, this can apply to disorders of the nervous system as well as fractures or other causes of pain that are worse by walking. Nevertheless, gait disruption, in this sense, refers to difficulties walking as a result of a neurological or muscular condition.

13. When a person stands with their feet and ankles together, the stance is unnatural and is characterized by the outward bending of the legs.

14. The metaphyseal areas of long bones enlarge abnormally.

15. Early-onset arthritis.

16. The existence of a spine with an aberrant lateral curvature.

17. The distal interphalangeal joint flexion point or the most distal interphalangeal crease are both close to the finger's tip. Specifically, one or more of the finger's distal phalanxes have hypoplasia.

18. Feet with equiovarus (turned down and under).

19. Due to missing or undeveloped vertebrae, neck issues are a regular occurrence.

20. Infants with respiratory issues due to a tiny chest.

21. Eye issues are prevalent and include retinal detachment.

How Is Congenital Spondylometaphyseal Dysplasia Diagnosed?

Spondylometaphyseal dysplasia is diagnosed by a clinician using a thorough medical history, physical exam, thorough neurological exam, post-traumatic trochanteric elevation or femoral neck pseudarthrosis, and diagnostic testing.

Some diagnostic techniques include:

1. X-rays of the pelvis, lower limbs, neck, and spine.

2. MRI (magnetic resonance imaging) of the spinal cord to check for cord compression.

3. Arthrograms, in which the hips are injected with a dye to examine the cartilage.

Will Spondylometaphyseal Dysplasia Result in a Waddling Gait or Walk?

• In myopathies, for example, weak hip girdle and upper thigh muscles contribute to pelvic instability during standing and walking.

• Hip posture gets flexed, and lumbar lordosis rises if the muscles that stretch the hip joint are compromised. The patients typically struggle to get out of a seated position.

• The hip on the side of the swinging leg descends with each stride as a result of weakening in the gluteus medius muscle (referred to as the Trendelenburg sign).

• The movement seems to waddle.

• The patients typically attempt to turn their trunk toward the side that is in the stance phase to prevent the hip on the swinging side from falling.

What Is the Treatment of Spondylometaphyseal Dysplasia?

Depending on the orthopedic disorders it is connected with, spondyloepiphyseal dysplasia congenital treatment may include:

1. Halo and vest may be necessary for cervical fusion and potential cervical spine (neck) decompression.

2. If scoliosis and kyphosis are detected early, bracing is recommended.

3. Fusion of the spine for kyphosis and scoliosis.

4. Hip osteotomy to address misalignment and subluxation (partial dislocation and hip flexion contractures).

5. Casting for foot malformations.

6. Individualized complete joint replacements.

Conclusion

Spondylometaphyseal dysplasia, Kozlowski type, is a bone disorder that affects the trunk and is characterized by short stature. This disease's symptoms may first manifest in an infant. The age at which symptoms may first develop varies depending on the condition. A single age range may or may not see the onset of symptoms. Certain illnesses can manifest symptoms at any age. Knowing when symptoms first appeared might aid doctors in making the correct diagnosis.