Single-Event Multilevel Surgery

Also known as: SEMLS

What is single-event multilevel surgery?

For some children with medical conditions like cerebral palsy, spina bifida and other neuromuscular disorders, they may have multiple issues with the soft tissue and bones in their lower extremities that require correction.

Single-event multilevel surgery, or SEMLS, is a surgical procedure that aims to correct many of these issues in just one orthopedic surgical procedure.

This results in fewer procedures and a shorter rehabilitation for the patient. It often results in better mobility, improved walking ability and reduced pain for patients over time.

What happens during the treatment?

SEMLS is a major surgery and, depending on what procedures are performed, can last several hours. Children who undergo the procedure often stay in the hospital for one to three days, and physical therapy can start during the hospital stay.

Before the surgery, a child will receive general anesthesia and will be unconscious for the procedure. They will also receive both a breathing tube and an IV tube that delivers fluids and anesthesia during the procedure. The surgeon will mark the areas on the body where incisions will be made, and then begin the process of correcting bone and soft tissue problems within the lower extremities.

In some cases, your child may require a special pillows, braces, or casts to immobilize and protect the repairs while they heal.

Is any special preparation needed?

Because neuromuscular patients have other medical conditions, your pediatrician, neurologist, cardiologist and other members of your child’s health care team may visit the child and provide their recommendations around the time of the surgery. This may involve adjusting or stopping certain medications prior to the procedure.

Our surgical nurses will guide you in this preparation. In addition, eating a healthy diet and managing stress can help with recovery both before and after the procedure.

What are the risk factors?

SEMLS is a major surgical procedure. Your child may experience pain, redness and puffiness and may require a casts and braces after the procedure.

The surgery is also followed by a lengthy recovery and rehabilitation process that can last up to a year in order to achieve new baseline.  However, many patients have very good outcomes from SEMLS and experience great improvements in mobility and reduced pain over time.


Reviewed by: Monica Payares-Lizano, MD

This page was last updated on: October 27, 2021 04:00 PM

Neuromuscular and Movement Disorders Program

Specializing in the treatment of muscular dystrophies, neuropathies, spinal muscular atrophy and congenital myopathies.

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Spina Bifida

Please see Myelomeningocele for further information.

Cerebral Palsy

Cerebral palsy (CP) is a neurological disorder, often as a consequence of events in the early years of life, which affect the neurological function at various levels. Children may have difficulty in moving in a coordinated manner, learning and behavioral problems or seizures. Learn more