A combination of elements defines a comprehensive physical examination including: observation of gait and posture, assessment of motor function (GMFCS and functional mobility scale [FMS]), assessment of muscle spasticity and presence of dystonia, evaluation for the presence of joint contractures, quantification of torsional abnormalities of the long bone including femoral neck anteversion and tibial rotation, selective motor assessment, and sensory examination.

When considering SEMLS, it is important to assess for the presence of hip subluxation or acetabular dysplasia, pes valgus, scoliosis and torsional abnormalities. An anteroposterior view of the pelvis will identify hip pathology related to subluxation. A computed tomography (CT) scan, specifically a murphy protocol can identify torsional abnormalities of the femur (anteversion) and tibia (torsion). Standing scoliosis radiographs should be taken in those children where clinical examination demonstrates pelvis obliquity or concern for scoliosis. In addition, standing foot x-rays are important to demonstrate lever arm dysfunction and significant pes planus.

Spastic hemiplegia has been classified into 4 patterns by Winters et al.⁶ These 4 patterns have been used as a template for the prescription of orthoses, spasticity management, and musculoskeletal surgery.

Type I hemiplegia: Characterized by drop foot in swing phase and loss of motor function to tibialis anterior without evidence of contracture. Management here can be with a hinged ankle foot orthosis (AFO) or posterior leaf spring AFO.

Type II hemiplegia: Spasticity of the gastrocsoleus complex and development of contracture are present. First and second rockers of the gait cycle have been disrupted, seen with excessive plantar flexion. Correction of the fixed contracture can be achieved with soft tissue lengthening at the gastrocsoleus complex (typically a Vulpius calf lengthening).

Type III hemiplegia: In addition to gastrocsoleus contracture, there is now cocontracture of the rectus and hamstring muscles. Spasticity management and consideration of lengthening of the medial hamstrings and rectus femoris transfer/lengthening.

Type IV hemiplegia: In this pattern, in addition to the gastrocsoleus and hamstring/rectus spasticity, there is now femoral anteversion, hip adduction, and flexion with the presence of acetabular dysplasia. This pattern typically requires femoral and acetabular surgery in addition to the surgical recipe outlined below.

Spastic diplegia has 4 sagittal gait patterns coined: true equinus, jump gait, apparent equinus, and crouch gait.⁷

True equinus: Characterized by overactivity of the plantar flexion knee extension couple, with the resultant ground reactive force lying anterior to the knee throughout stance phase. Often single-level surgery for the gastrocsoleus contracture is the incorrect strategy as there is often concomitant contractures of the hamstring and iliopsoas.

Jump gait: This gait pattern is characterized by spasticity of the hip flexors, hamstrings, and gastrocsoleus complex with incomplete hip and knee extension coupled with equinus at the ankle. This is the most common preadolescent pattern of spastic diplegia and these children typically benefit from SEMLS.

Apparent equinus: Many children may walk on their toes, but be wary of falling into the trap of assuming that ankle equinus is driving the observed incomplete heel strike seen with observational gait analysis (OGA). The savvy practitioner must examine the joint above and below the main deviation as often hip or knee flexion contractures may be responsible for the appearance of ankle equinus. The neuromuscular orthopedic surgeon must first recognize this gait pattern and then understand that calf lengthening here will worsen this gait pattern. IGA is helpful to differentiate true versus apparent equinus. Apparent equinus is often a transitional gait pattern from jump gait to crouch gait as lever arm dysfunction progress with growth and worsening spasticity. If you see a child who continues with an incomplete heel strike despite being in AFOs, consider apparent equinus.

Crouch gait: Crouch gait is described as increased hip and knee flexion and excessive ankle dorsiflexion in midstance. The soleus muscle is often overlengthening in this gait pattern and is commonly seen in adolescence. Overlengthening of the Achilles tendon can cause this gait pattern. Hamstring length can be assumed to be short due to this gait pattern but rarely is hamstring lengthening necessary, which will further exacerbate anterior pelvic tilt in this cohort of adolescents.

A series of surgical interventions can be included in the surgical recipe for SEMLS. The overarching theme is to preserve muscle length and strength and improve lever arm dysfunction and torsional abnormalities. It is important not to only focus on the physical deformities or anatomic abnormalities when considering SEMLS surgery. To be successful, one must consider the patient in the context of the World Health Organization—International Classification of Function,⁸ where we consider not only the body and structural abnormalities of the patient but how the child interacts and functions within their environment. Trying to align the goals of the surgeon and child/family are critical at the outset to have a successful surgical intervention. The goal in SEMLS is not only to improve the anatomic and structural deficits but also to improve the child’s function, mobility, and participation in their current environment. Spend time and identify what is important to your child and the family and make sure that the surgical goals or interventions that you are recommending are aligned with their goals and expectations. This is critical as the rehabilitation after SEMLS is long, challenging, and slow. It is important to outline that most ambulant children undergoing multilevel surgery will continue to see surgical gains 12 to 24 months after surgery. As a result, having an established therapy plan preoperatively is also important to ensure success of your surgical intervention.

Many of the soft tissue procedures utilized in SEMLS have been described elsewhere in the neuromuscular section; however, here we will describe iliopsoas lengthening over the brim, transfer of the semitendinosus around the adductor magnus tendon, and gastrocsoleus lengthening. Furthermore, bony correction for lever arm dysfunction has also been described elsewhere in the NM chapter, but we will outline some elements in the decision-making for isolated femoral and tibial derotation osteotomy.