summary Gait Disorders in Cerebral Palsy are commonly caused by lower limb spasticity and are the primary reason for orthopaedic consultations in CP patients. Diagnosis is made with quantitative evaluation using kinematic, kinetic and EMG analysis. Treatment is usually physical therapy, orthotics and bracing in patients with mild gait disorders. Single-event, multi-level surgery (SEMLS) has become the gold standard surgical intervention for patients with continued difficulty with gait. Epidemiology Incidence gait disorder is the primary reason for orthopaedic consultations in CP patients independent gait expected between 12 to 18 months old in non-CP children Etiology Cerebral Palsy General Pathophysiology Divided into: primary deviations those caused by the primary CNS insult including spasticity weakness compromised proprioceptive pathways secondary deviations growth-related deviations that arise due to abnormal loading in the setting of primary gait deviations, including: anatomic shortening of muscle-tendon units (e.g., myotatic contractures) persistent bony deformities (e.g., femoral anteversion) joint subluxations/dislocations (e.g., hip subluxation or equinoplanovalgus feet) tertiary deviations compensations related to secondary gait deviations Etiology both qualitative and quantitative analysis has been used to describe gait quantitative evaluation (kinematic/kinetic/EMG analysis) have changed how we understand, classify, and treat this condition new treatment strategies focus on understanding the underlying pathophysiology (deviations) planes of deformity (sagittal, coronal, transverse) anatomic level (hip, knee, ankle) Classification Descriptive (Qualitative) classification useful for simplification, though high variability of segmental deviations in each pattern descriptive classifications have been unsuccessful at classifying up to 40% of CP gait patterns. common descriptive classifications are shown in table below. Descriptive Classification Equinus Gait Term "equinus" used to refer to the isoloated abnormality in foot position relative to the tibia, i.e. a one-level deviation (e.g. no knee/hip involvement) characterized by absence of heal strike during gait isolated equinus gait is common in hemiplegics Equinus is either: true equinus: defined by the foot position in relationship to the tibia being less than plantigrade apparent equinus: defined by a foot position that is normal in relationship to the tibia, however heel strike does not occur due to more proximal deviations (flexion of the knee most common) Jump Gait Deformity includes hip flexion, knee flexion, and equinus ankle deformity ( could result in apparent ankle equinus) Multi-level gait deviations where treatment of underlying spasticity should be considered Crouch Gait A combination of hip flexion, knee flexion, and excessive ankle dorsiflexion (the latter may be represented by flatfoot or calcaneus) Common in diplegic CP Pathophysiology: often an iatrogenic consequence of isolated lengthening the achilles in a jump gait pattern if the other levels of gait deviations are not addressed properly Levels of deviation Calcaneal contact pattern throughout stance phase Increased knee flexion throughout stance phase due to disruption of the ankle plantar flexion-knee extension couple Compensated crouch gait refers to tertiary deviations that allow the knee extensor mechanism to be off-loaded during stance phase (e.g. pelvic or truncal forward tilt) - this may be well-tolerated by younger children with CP and low body mass Uncompensated crouch gait occurs secondary to persistent overloading of the extensor mechanism. This occurs in all crouch eventually, if untreated Stiff Knee Gait Common in spastic diplegic CP Characterized by limited knee flexion in swing phase due to rectus femoris firing out of phase (seen on EMG) note the above gait decriptions are stance phase deviations Evaluation gait analysis reveals quadriceps activity from terminal stance throughout swing phase Complications Stiff knee gait can be a compensation due to deviations at the hip; surgical management will not help this subset of stiff-knee gait Term "equinus" used to refer to the isoloated abnormality in foot position relative to the tibia, i.e. a one-level deviation (e.g. no knee/hip involvement) characterized by absence of heal strike during gait isolated equinus gait is common in hemiplegics Equinus is either: true equinus defined by the foot position in relationship to the tibia being less than plantigrade apparent equinus defined by a foot position that is normal in relationship to the tibia, however heel strike does not occur due to more proximal deviations (flexion of the knee most common) Quantitative classification uses technology to better characterize the pathoanatomy of abnormal gait, particularly when multiple planes and segments of deformity exist characterizes gait into 3 planes of deformity sagittal plane includes: anterior or posterior pelvic tilt hip flexion/extension knee flexion/extension ankle dorsiflexion/plantarflexion coronal plane includes: pelvic elevation/depression hip abduction/adduction transverse plane transverse plane is least reliable plane described in instrumented gait analysis includes: pelvic and hip internal and external rotation deformities, foot progression angle Comprehensive Gait Analysis Gait analysis has helped identify distinct problems and guide orthopaedic treatment quantitative gait analysis is more accurate at detecting gait abnormalities than is qualitative assessment alone comprehensive gait analysis may include the following components: physical exam findings spasticity assessment, contractures and torsional abnormalities kinetic analysis forces (procuce linear accelerations) and moments (produce rotational accelerations) acting on and within the body kinematic analysis description of movement, typically described in segments and joints in 3 planes sagittal/coronal/transverse pedobarography special force plate that shows contact pressures through the stance phase dynamic electromyography muscle activation detected at different (normal or abnormal) start points in gait video Treatment Nonoperative physical therapy indications plays an important role in both operative an nonoperatively treated patients chemodenervation (botulinum neurotoxin A) may be used to temporize certain muscle groups in order to delay surgical management or as a primary treatment modality indications hamstring spasticity without fixed deformity in ambulatory patient orthoses solid ankle foot orthosis (AFO) indications flexible equinus deformities ankle is passively correctable to neutral while maintaining a subtalar neutral position posterior leaf-spring (or hinged) orthoses indications used in presence of excessive ankle plantar flexion in the swing phase Operative single-event, multi-level surgery (SEMLS) overview SEMLS approach has become the gold-standard of CP gait surgery goal is to address all primary (spasticity) and secondary (i.e. contractures) deviations at multiple levels during a single surgery addressing multiple deviations at once is essential to avoiding iatrogenic worsening of gait procedures used during a SEMLS lever arm dysfunction due to increased femoral anteversion: external rotation proximal femur osteotomy hip flexion contracture: intramuscular psoas lengthening knee contractures medial hamstring lengthening(lateral may result in excessive weakness) if minimal fixed contracture guided growth distal femur extension osteotomy rectus transfer for stiff knee gait equinus: tendo-achilles lengthening or gastrocnemius recession flatfoot reconstruction rehabilitation AFOs and aggressive physical therapy for re-training and strengthening following releases is an essential component of SEMLS intervention expect one year for recovery Techniques External rotation proximal femur osteotomy indications femoral anteversion / hip internal rotation deviation Rectus Transfer indications stiff knee gait technique create knee flexion vector with rectus activation by transferring it posterior to the center of rotation of the knee Medial hamstring lengthening indications for mild knee dysfunction, usually younger patients with less than 5 degrees knee flexion deformity technique fractional lengthening at the myotendinous junction is ideal complications hamstring contractures often recur, especially in jump gait Guided growth surgery indications knee flexion deformities of 10-25 degrees in the patients with at least two years of growth remaining Supracondylar femur extension osteotomy +/- patellar tendon advancement or shortening indications for knee flexion deformities of 10-30 degrees, with severe quadriceps lag close to or already at skeletal maturity Gastrocnemius recession indications Silfverskiöld test positive technique horizontal or vertical incision at the level of the myotendinous junction of the gastroc identify and protect the sural nerve (superficial to fascia) sharply divide the tendon only, preserving the muscle fibers not yet joined to the tendon incise all deeper bands that prevent release of contracture (small raphes may be present in the tendon manipulate the ankle goal of treatment is 10 degrees of dorsiflexion Tendo-achilles lengthening indications rigid deformities - ankle is not passively correctable to neutral true equinus Silfverskiöld negative contraindications spastic diplegia leads to excessive weakening and development of calcaneus/crouch gait techniques multiple hemi-lengthenings or a Z-lengthening can be performed avoid overlengthning Complications Recurrent hamstring contracture Worsening crouch gait secondary to isolated and overlengthening of achilles Patella alta elongated patellar tendon (patellar alta) is another complication of this condition that is difficult to treat Multiple simultaneous soft tissue releases without careful gait analysis Knee pain tendo-achilles lengthening may worsen knee pathology if careful gait analysis isn't performed