The biggest problem in the lives of individuals with achondroplasia is their spine. Spinal stenosis and all the ramifications of it is the primary reason for pain and disability in the achondroplasia population.
Spinal stenosis is the narrowing of the spinal column causing compression of the spinal cord and/or nerve roots. The spinal cord has various important functions like controlling breathing, bowel and bladder function as well as movement of the legs, feet, arms and hands. When the spinal cord is compressed, these functions become compromised. Pain in the limbs is also a significant component of spinal stenosis.
This is the most common complaint and source of disability for patients with achondroplasia. Intervention and treatment should not wait until the individual is weak, parlayzed or urinary incontinent. There are solutions that are quite effective and can be life changing.
Why is spinal stenosis common in achondroplasia?
Due to the abnormal formation of the vertebrae (bones making up the spine) in achondroplastic patients, the spinal column is narrowed providing less room for the spinal cord/nerve roots. Other factors that come into play such as excessive lumbar lordosis/kyphosis. These all can lead to compression.
Who does it affect?
Both children and adults with achondroplasia can suffer from the impact of spinal stenosis. Infants and young children should be closely monitored for foramen magnum stenosis (cervical cord compression). Stenosis of the thoracic and lumbar spine is most often seen in adults beginning in their twenties but can also occur as young as adolescence.
Area of the spine impacted
While generalized spinal canal stenosis is a consistent complication in individuals with achondroplasia, there are two areas of the spine that are particularly vulnerable. These are the foramen magnum (opening at the base of the skull where the brainstem and spinal cord pass through) and the thoracolumbar region (mid to lower back).
Regardless of whether the stenosis occurs in the cervical, thoracic or lumbar vertebrae, symptoms can lead to significant limitations in physical functioning and quality of life for patients.
Significant compression at the foramen magnum can lead to several neurological complications, including sleep apnea, disrupted breathing pattern, hydrocephalus, myelopathy and even sudden infant death.
The most common symptom of lumbar and thoracic stenosis is pain which occurs in the lower back, buttocks and/or front of the thighs. Patients often recall having to squat down or bend forward to relieve discomfort when walking even short distances. The severity of the pain increases with activity. Numbness, tingling and weakness can be experienced. Loss of bowel or bladder control can also occur and is an indication of severe stenosis that requires immediate attention.
Patients with achondroplasia should be seen by a physician, who is familiar with skeletal dysplasia, to monitor the spine and ensure that the individual is not showing signs of early onset stenosis beginning in infancy. Physical evaluation as well as x-ray, Cat scan or MRI are very important. It may be recommended that infants also undergo a sleep study. Parents and caretakers need to be educated regarding safe early positioning and handling of an infant with achondroplasia as it is beneficial in reducing the risks associated with cervical compression. Careful handling around the head and neck area in young infants and the avoidance of baby equipment like seats to prop up the baby such as the Bumbo and carrying slings, all of which may trigger sudden, uncontrolled head movements and/or compromise the child’s ability to develop core stability.
Screening for thoracolumbar stenosis is much easier to evaluate in older children and adults with regular doctor visits and routine x-ray and when needed MRI.
Treatment is always determined on a case by case basis.
To relieve the pressure on the cervical spinal cord a proportion of young children with achondroplasia will require cervicomedullary decompression (CMD) surgery. A foramen magnum decompression involves removing a small part of the base of the skull and sometimes parts of the top of the spine to take the pressure off the top of the spinal cord and should be performed by a team familiar with treating individuals with skeletal dysplasia.
For treatment of thoracic or lumbar stenosis, surgical procedures such as a decompressive laminectomy to spinal fusion are necessary. A spinal fusion is the most effective surgical treatment option for severe cases of spinal stenosis associated with spinal deformity such as Kyphosis. Rods and screws are attached to the vertebrae to fuse (weld) the bones together helping to straighten the spine and open up the spinal canal relieving the compression on the spinal cord.
While many individuals with achondroplasia fear spinal fusion, if there is a deformity of the spine, fusion is the only viable option. If the spine is left unfused then instability will often ensue and lead to severe kyphosis (hunchback). The fusion is safe and effective in preventing this problem. Often to ensure fusion, a minimally invasive anterior fusion is performed at the lowest level.
Recovery time and Rehabilitation
It can take anywhere from 2 to 6 weeks to get back to doing simple activities, like driving a car. The important thing to remember is not to rush the healing process. Most patients will tell you that it takes a year to fully heal. Complete recovery from spinal fusion surgery usually takes up to 8 months, with the bone continuing to harden up to 12 months. In some situations where the nerves had significant injury prior to surgery, it may take up to 1 to 2 years to see how well the nerves will heal.
Although surgeons may not stress physical therapy for the first few months following a spinal fusion, it is important to not be sedentary. It is advisable to attend a few sessions of physical therapy so therapists can establish your restrictions with body mechanics, ensure your safety while using a walker, if necessary, and create a home exercise program for you. Walking is the best modality for the patient along with pool therapy once the incision has healed. While the fusion is growing together and strengthening, movements such as lifting anything heavier than 10 to 15 pounds, excessive bending and twisting side to side should be avoided.
As the surgical pain subsides, returning to physical therapy or seeking help from a personal trainer to work on core strengthening exercises and stability is important. The more intense rehabilitation becomes required after you are completely healed. Techniques are tailored to the individual, with more and more activities added as strength builds. Physical therapy helps patients stay aware of how they walk, sit, stand, and lie down to help prevent back pain from recurring. Safe ways to lift, pull, or push objects are also covered.
Due to the trauma of surgery, the patient’s core and back muscles, and overall condition will most often become weakened. A loss of muscle tone and reduced range of motion can lead to stiffness. Although this can be addressed with exercise and physical therapy, patients may also benefit from integrative massage, acupuncture and other methods of wellness.
Individuals who undergo an extensive fusion may want to have the conversation regarding arm lengthening. The restrictive motion from being fused can make personal hygiene and other activities of daily living very challenging. We have several patients who have chosen to have their humeri (upper arms) lengthened to make such activities easier.
Moving forward after a fusion.
Dedication to rehabilitation and healing after a fusion for spinal stenosis cannot be stressed enough. It is a process that also cannot be rushed. It is also important to see your surgeon for routine yearly x-rays and appointments to continue monitoring the spine and fusion.
Living life in pain should never be an option. With the proper course of treatment, individuals with achondroplasia who undergo fusions make a full recovery and are able to live their lives free of pain. Our team is dedicated to ensuring the best outcome for our patients.