Kniest Syndrome: What You Need to Know
- Kniest syndrome is a form of skeletal dysplasia affecting the cartilage.
- A physical exam is used to diagnose Kniest syndrome, along with X-rays and/or arthrograms.
- Treatment is usually based on the associated orthopaedic conditions that present in a patient with Kniest syndrome.
What is Kniest syndrome?
Kniest syndrome is a genetic disorder stemming from a type 2 collagen defect (COL2A1) passed on autosomal dominant (one parent passes on the disorder). It affects the cartilage, making it soft and crumbly with a Swiss cheese appearance.
What are the symptoms of Kneist syndrome?
Common symptoms seen in patients with Kniest syndrome include:
- Prominent eyes and foreheads
- A depressed midface
- Large joints (hips and knees) are big, stiff and knobby
- Small joints (fingers) are affected as the patient ages
- Cleft palate
- Chronic hearing loss
- Eye problems, such as glaucoma and retinal detachment
The spine and epiphysis (the rounded end of the long bones) are also affected by Kniest syndrome.
Orthopedic Conditions Seen with Kneist Syndrome
Orthopaedic conditions commonly associated with Kniest syndrome include:
- Cervical instability if there is an abnormal amount of motion the cervical spine needs to be stabilized
Kyphosis and or scoliosis (curvature and or rounding of the back) may be present early and can be progressive.
- Stiff joints and premature arthritis
- Lower extremity misalignment
Kneist Syndrome Diagnosis
The doctor makes the diagnosis of Kniest syndrome with a complete medical history, physical examination and diagnostic tests.
Diagnostic procedures may include:
X-rays of the spine—to check for cervical instability, scoliosis and kyphosis—and lower extremities
Arthrograms: Injection of dye in the hips, knees and or ankle to assess the cartilage in the joints and evaluate for lower limb misalignment prior to surgical correction
Kneist Syndrome Treatment
Treatment for Kniest syndrome varies depending on the associated orthopaedic conditions that present in the patient. The following includes information about individual treatment options by condition:
- Cervical fusion and placement of a halo and vest may be done if the patient has cervical instability
- Growing rods to control scoliosis when young
- Posterior spinal fusion for scoliosis and kyphosis when growth is complete
- Aqua therapy to keep muscles strong and preserve motion.
- Osteotomies for hip containment, contracture correction and misalignment
- Clubfeet casting, releases and/or fusions of feet if they are rigid