Mode of Anesthesia and Bladder Management Following Orthopaedic Surgery in Children With Cerebral Palsy: A System Level Analysis.

BACKGROUND: Postoperative urinary retention (POUR) is a surgical complication more prevalent in children with neurodisability and associated with an increase length of hospitalization. Risk factors include pre-existing bladder dysfunction, type and duration of surgery, anesthesia medications, postoperative opioid pain management, and patient demographics. The purpose of this investigation was (1) to determine the frequency of POUR following hip/lower limb orthopaedic procedures in which epidural analgesia was used for pain management; (2) to explore factors influencing postoperative bladder management. METHODS: A retrospective analysis of clinical data was performed in an orthopaedic specialty care health care system. A health outcomes network was queried for patients with a diagnoses of cerebral palsy (ICD-9/10 codes) who had one of 57 unique CPT procedure codes corresponding to hip osteotomies or tenotomies from 2011 to 2019. All surgical observations included in analysis required a discrete data element and the confirmation of a secondary proxy. The database was also queried for postoperative medications received and patient demographics of interest. RESULTS: A total of 704 surgical procedures met inclusion criteria resulting in a patient population with a mean age of 11 years, 58% male, 53% Caucasian, and 55% classified as quadriplegia [51% Gross Motor Function Classification System (GMFCS) levels IV/V]. Three hundred and thirty-five procedures (48%) involved epidural anesthesia. Sixty-five patients required intermittent catheterization (9.2%) postoperatively following foley catheter removal, of which 23 (3.3%) required recatheterization. The rate of recatheterization was similar regardless of anesthesia mode; 1.8% for general and 1.4% for epidural and was associated with a greater number of pain medications. Epidural anesthesia resulted in significantly longer periods of catheterization. For the total group the time to urinary catheter removal differed significantly among cerebral palsy subtypes, GMFCS Level, race, and ethnicity. Factors identified as significant predictors of the length of catheterization were epidural analgesia, number of pain medications, and osteotomy. CONCLUSIONS: The number of postoperative pain medications utilized was more predictive of POUR than the mode of analgesia delivery; however, epidural analgesia and the type of surgical procedure did significantly impact the length of catheterization. LEVEL OF EVIDENCE: Level III.

A degradation fragment of type X collagen is a real-time marker for bone growth velocity.

Despite its importance as a key parameter of child health and development, growth velocity is difficult to determine in real time because skeletal growth is slow and clinical tools to accurately detect very small increments of growth do not exist. We report discovery of a marker for skeletal growth in infants and children. The intact trimeric noncollagenous 1 (NC1) domain of type X collagen, the marker we designated as CXM for Collagen X Marker, is a degradation by-product of endochondral ossification that is released into the circulation in proportion to overall growth plate activity. This marker corresponds to the rate of linear bone growth at time of measurement. Serum concentrations of CXM plotted against age show a pattern similar to well-established height growth velocity curves and correlate with height growth velocity calculated from incremental height measurements in this study. The CXM marker is stable once collected and can be accurately assayed in serum, plasma, and dried blood spots. CXM testing may be useful for monitoring growth in the pediatric population, especially responses of infants and children with genetic and acquired growth disorders to interventions that target the underlying growth disturbances. The utility of CXM may potentially extend to managing other conditions such as fracture healing, scoliosis, arthritis, or cancer.

Safety and Efficacy of Botulinum Toxin A in Children Undergoing Lower Limb Lengthening and Deformity Correction: Results of a Double-blind, Multicenter, Randomized Controlled Trial.

BACKGROUND: Lengthening of the lower limb is a complex procedure in which pain management and complications such as pin-site infections and muscle contractures impact the family and affect the child's quality of life. As a result, the paralytic and antinociceptive actions of neurotoxins may be indicated in managing these complications; however, few studies have explored ways to improve outcomes after lengthenings. The objective of this study was to evaluate the safety and efficacy of botulinum toxin A (BTX-A) in children undergoing lower limb lengthenings and deformity correction. METHODS: Participants with a congenital or acquired deformity of the lower extremity requiring surgery to one limb were randomized to receiving either BTX-A as a single dose of 10 units per kilogram body weight, or an equivalent volume of saline solution. Pain, medication, quality of life, and physical function were assessed at different time-points. Adverse events were recorded in all participants. T test and χ tests were used to compare potential differences across both groups. RESULTS: Mean age of the 125 participants was 12.5 years (range, 5 to 21 y), and lengthenings averaged 4.2 cm. Maximum pain scores on day 1 postoperatively were lower in the BTX-A group (P=0.03) than in the placebo group, and remained significant favoring botox when stratifying by location of lengthening (femur vs. tibia). Clinical benefits for BTX-A were found for 3 quality of life domains at mid-distraction and end-distraction. When stratifying according to location of lengthening, there were significantly fewer pin-site infections in the tibia favoring botox (P=0.03). The amount of adverse events and bone healing indices were no different in both groups. CONCLUSIONS: The clinical differences in quality of life, the lower pain on the first postoperative day, and the lower number of pin-site infections in the tibia favoring BTX-A support its use as an adjunctive treatment to the lengthening process. The detailed analyses of pain patterns help inform families on the pain expectations during lower limb lengthenings. The amount of adverse events were no different in both groups, and bone healing rates were similar, indicating that the use of BTX-A in children undergoing limb lengthening and deformity correction is safe. LEVEL OF EVIDENCE: Level I.

A comparison of the changes in the energy cost of walking between children with cerebral palsy and able-bodied peers over one year.

For ambulatory children with cerebral palsy, the assessment of walking energy efficiency is utilized to determine functional changes following surgical, pharmacologic, or orthotic interventions. While the assessment of energy efficiency is considered a useful outcome tool, minimal information exists about the changes in energy efficiency over one year in children with cerebral palsy at different gross motor function classification system (GMFCS) levels and whether the patterns of change are similar to their able-bodied peers. The purpose of this study was to determine whether energy efficiency variables change similarly over one year in children with cerebral palsy by GMFCS level and whether they differ from their age-matched peers. Forty-five able-bodied children and 34 children with cerebral palsy, GMFCS levels I-III participated in the study. Energy efficiency variables were measured at baseline and at 12 months using a Cosmed K4b2. All subjects walked at their self-selected velocity for testing around a 33 m track. Baseline velocity and net non-dimensional cost (NNcost) differed by GMFCS level and between the able-bodied peers and all GMFCS levels. Children in GMFCS level III had the highest cost and the slowest velocity. When controlling for age and baseline values, significant differences in the magnitude of change were seen in velocity between children in GMFCS level III and children in GMFCS level I and II and their able-bodied peers. In comparison to their able-bodied peers, all GMFCS levels had an increase in NNcost over one year when controlling for age and baseline NNcost, with the difference in magnitude increasing by GMFCS level. Consistent with the literature, children with cerebral palsy had an increase in NNcost over one year in comparison to their able-bodied peers, which increased with GMFCS level. This finding demonstrates that when evaluating the change in walking energy efficiency with maturation and therapeutic intervention, comparisons should be made by GMFCS level.

Varus derotation osteotomy for the treatment of hip subluxation and dislocation in GMFCS level III to V patients with unilateral hip involvement. Follow-up at skeletal maturity.

PURPOSE: Hip displacement is common in children with cerebral palsy (CP). The risk of hip displacement is related to gross motor function level as graded with the Gross Motor Function Classification System (GMFCS). Most clinicians agree that surgical treatment is indicated for progressive hip subluxation in patients with CP. However, it is unclear whether unilateral bony surgery and musculotenduous release is effective in cases in which the contralateral hip is well seated. The purpose of this study is to describe the fate of the original and the contralateral hip of severely involved patients with CP, GMFCS III to V, with unilateral hip subluxation or dislocation treated by unilateral femoral osteotomy with or without pelvic osteotomy along with unilateral or bilateral soft tissue release when the contralateral hip was well seated followed to skeletal maturity. METHODS: A continuous group of GMFCS III to V CP patients with unilateral hip subluxation or dislocation who underwent soft tissue release (adductor and iliopsoas) and unilateral intertrochanteric varus, rotation and shortening osteotomy with or without pelvic osteotomy are included. All patients were clinically and radiologically followed from the time of presentation until skeletal maturity. RESULTS: Twenty-seven children and adolescents with GMFCS level III, IV, and V met the inclusion criteria. Two patients (7.4%) were GMFCS III, 5 (18.5%) were GMFCS IV and 20 (74.1%) GMFCS V. The male:female ratio was almost 1 (13 boys and 14 girls). At the time of chart and radiograph review, the average age of this patient group was 20.4 years (range: 14 to 25 y). Twelve patients (44%) required subsequent bony surgical management of the contralateral hip for subluxation or dislocation after the index procedure. Initially, in all cases there was pelvic obliquity with the operative side higher, which reversed in cases in which the contralateral hip deteriorated, and did not reverse when the contralateral hip remained stable. Nine of them were treated with femoral varus osteotomy alone and 3 underwent a combination of femoral and pelvic osteotomy. Three of these 12 (25%) patients had revision of the first hip and bony correction of the contralateral hip. Age at surgery did not seem to have a significant effect on maintaining reduction or in preventing the contralateral hip to deteriorate. CONCLUSIONS: The rates of recurrence of the original hip and contralateral hip subluxation and dislocation after unilateral bony surgery in GMFCS III to V spastic patients are higher than those of other earlier series. However, in this series patients were followed until skeletal maturity. It is prudent to warn families of the possibility of long-term subluxation or dislocation of the original hip and development of the hip dysplasia requiring surgery on the contralateral side. Consideration should be given to adductor and iliopsoas release and bony surgery on the contralateral side in a GMFCS level III to V child undergoing surgery for hip displacement, even when the hip seem radiologically normal. If unilateral bony surgery is carried out, close radiological follow-up of both hips is recommended. It also seems that unilateral hip surgery alters the forces maintaining pelvic alignment, which can lead to destabilization of the contralateral hip. LEVEL OF EVIDENCE: Case series. Level IV.

Variability and minimum detectable change for walking energy efficiency variables in children with cerebral palsy.

For individuals with neuromuscular disorders, the assessment of walking energy efficiency is useful as a clinical outcome measure. Issues surrounding data collection methodology, normalization of the data, and variability and clinical utility of energy efficiency data preclude universal application. This study examined the variability and the clinical utility of velocity, energy efficiency index (EEI), gross cost, and net nondimensional cost (NNcost) in children and adolescents with spastic diplegic cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels I to III. The energy efficiency of walking was evaluated in 23 children and adolescents (12 males, 11 females, mean age 11y 3mo [SD 3y 5mo]; range 7-17y). Day-to-day variability was similar for all energy efficiency variables, with no significant differences in magnitude of variability between GMFCS levels. Correlations between EEI and gross cost and EEI and NNcost were fairly good (r=0.65, p<0.001, and r=0.74, p<0.001 respectively). However, only gross cost and NNcost discriminated between GMFCS levels in children with CP. Gross cost required the greatest amount of change to be considered clinically significant, whereas NNcost and EEI required a similar amount of change. For cohorts of children with CP who are evaluated over time, NNcost is the best normalization method as it reduces the variability between participants of different ages, height, and weight while evaluating only the amount of energy used to ambulate.

Botulinum toxin type A injection in alleviating postoperative pain and improving quality of life in lower extremity limb lengthening and deformity correction: a pilot study.

BACKGROUND: The Ilizarov technique is commonly used for lengthening and deformity corrections of the lower limbs in children. Postoperative pain can be significant, affecting quality of life and functional mobility, and often requiring prolonged medication use. Several studies have investigated the antinociceptive actions of botulinum toxin type A (BtX-A), yet evidence for its use in this population is limited. The objectives were to (1) establish the feasibility of a randomized clinical trial in children undergoing limb lengthening or deformity correction and (2) provide preliminary evidence of the beneficial effects of BtX-A in this population. METHODS: Fifty-two patients with a mean age of 13.7 years (range, 5 to 21 y) were randomized to receive either BtX-A or an equivalent volume of sterile saline solution (placebo group), as a single dose during the surgical procedure. Pain, medication use, quality of life, and functional mobility outcomes were assessed in all patients. Adverse events were reported for all patients and classified as minor or major. RESULTS: Differences between groups did not reach statistical significance; however, pain at mid-distraction was found to be slightly lower in the BtX-A group, as compared with the placebo group. Patients in the BtX-A group used less parenteral pain medication in the first 4 days after the surgery, had higher quality of life scores at 3 of the 5 time points assessed, and slightly higher functional mobility scores. All adverse events were expected complications of the lengthening process. No event was considered to be a serious adverse event related to the BtX-A injection itself. There was a trend toward fewer major adverse events in the BtX-A group. CONCLUSIONS: This pilot study established the feasibility of a randomized controlled trial design for in this population. Its findings indicate that BtX-A injections appear to be safe and effective for reducing pain and improving the quality of life and functional mobility of children undergoing lengthening or deformity corrections of the lower limbs. A larger-scale study is currently underway to confirm these preliminary findings.

Iliopsoas tenotomy at the lesser trochanter versus at the pelvic brim in ambulatory children with cerebral palsy.

BACKGROUND: Progressive hip flexion deformity is a common problem in ambulatory children with spastic cerebral palsy, causing static and dynamic deformity. The iliopsoas muscle is recognized as a major deforming force in the development of this problem. Many clinicians address this problem by lengthening the iliopsoas, either in an intramuscular location at the pelvic brim or by complete tenotomy at the lesser trochanter. The goal of this study was to compare the outcomes of patients with ambulatory cerebral palsy who had intramuscular lengthening at the pelvic brim to those who underwent complete release of the iliopsoas tendon at the level of the lesser trochanter. METHODS: Twenty patients were included in the study, 11 of whom had iliopsoas release at the lesser trochanter (group 1) and 9 of whom had intramuscular lengthening at the pelvic brim (group 2). All patients had physical examinations, plus kinematic and kinetic analyses in our gait laboratory before and 1 year after surgery. RESULTS: Hip flexion contracture was decreased significantly only in group 1, although there was a trend of decrease in group 2. There was a significant increase in maximum hip extension in terminal stance and a reciprocal decrease in maximum swing phase hip flexion in group 1, with a similar trend that did not reach significance in group 2. Stride length increased significantly in both groups. There was no significant change in power generation of hip flexion during the swing phase in either group. CONCLUSIONS: We found improved static and dynamic parameters of hip extension after iliopsoas lengthening and did not detect any adverse kinematic or kinetic change in hip function after surgery. The improvement was more robust in the group who underwent release at the lesser trochanter. Because there are no adverse effects of iliopsoas release from the lesser trochanter and the improvement in hip extension is greater, this approach should be considered in ambulatory patients with spastic diplegia when a hip flexor weakening procedure is considered. LEVEL OF EVIDENCE: Comparative cohort study, level III, case-control study.

Walking energy expenditure in able-bodied individuals: a comparison of common measures of energy efficiency.

Assessment of walking energy efficiency is potentially useful for objectively quantifying gait efficiency; however, issues regarding methodology, day-to-day variability, inter subject variability (age and size differences) and clinical relevance prevents the assessment of walking energy efficiency from being used as a standard assessment tool. Volume of oxygen (VO(2)) and heart rate were assessed to determine the intra-subject (day-to-day) variability, the impact of age and body parameters and the clinical relevance of gross cost, Net non-dimensional Cost (NNcost) and Energy Efficiency Index (EEI) in able-bodied individuals. Gross cost demonstrated the least amount of day-to-day variability, in comparison to NNcost and EEI. Age and body parameters contributed more to the variability in gross cost than NNcost and EEI. Only net non-dimensional oxygen consumption was related to the velocity of walking. EEI did not correlate with direct measures of oxygen cost. The results from this study demonstrate that utilization of NNcost, a measure that subtracts resting oxygen consumption from walking oxygen consumption and scales for body parameters, is preferable to the traditional measures for comparing individuals of different ages and sizes and is related to the speed that the individual walks.

Comparison of rectus femoris transposition with traditional transfer for treatment of stiff knee gait in patients with cerebral palsy.

PURPOSE: To assess the outcome of children with cerebral palsy following reposition of the distal rectus femoris tendon for treatment of stiff knee gait. METHODS: Children with cerebral palsy with stiff knee gait who underwent rectus femoris transfer were studied retrospectively. Inclusion criteria were cerebral palsy of diplegic or quadriplegic type, preoperative and 1 year postoperative three-dimensional motion analysis, and no other surgery except rectus femoris transfer at the time of study. The patients were separated into two groups: in group I, the rectus femoris was transferred to the distal medial hamstring tendons, either the gracilis or the semitendinosus; in group II, the distal tendon of the rectus femoris was transposed laterally and attached to the iliotibial band/intermuscular septum. RESULTS: Peak knee flexion during swing phase, total dynamic knee range of motion, knee range of motion during swing phase, and time to peak knee flexion during swing phase were all improved in both groups. Hip and pelvic kinematics were not influenced by the surgery. Velocity, stride length, and cadence were all improved following the surgery. There was no difference between the transfer group and the transposition group. CONCLUSION: These findings suggest that distal transfer of the rectus femoris is effective in improving swing phase knee function by diminishing the mechanical effect of the dysphasic swing phase activity of the rectus femoris, not by converting the rectus femoris to an active knee flexor.

Outcome of patients after Achilles tendon lengthening for treatment of idiopathic toe walking.

Fifteen children who were diagnosed with idiopathic toe walking that cannot be corrected by nonoperative treatment were assessed by clinical examination and computer-based gait analysis preoperatively and approximately 1 year after Achilles tendon lengthening. Passive dorsiflexion improved from a mean plantarflexion contracture of 8 degrees to dorsiflexion of 12 degrees after surgery. Ankle kinematics normalized, with mean ankle dorsiflexion in stance improving from -8 to 12 degrees and maximum swing phase dorsiflexion improving from -20 to 2 degrees. Peak ankle power generation increased from 2.05 to 2.37 W/kg but did not reach values of population norms. No patient demonstrated clinically relevant triceps surae weakness or a calcaneal gait pattern. Seven patients had a stance phase knee hyperextension preoperatively, and 6 of these corrected after surgery. Achilles tendon lengthening improves ankle kinematics without compromising triceps surae strength; however, plantarflexion power does not reach normal levels at 1 year after surgery.

Comparing botulinum toxin A with casting for treatment of dynamic equinus in children with cerebral palsy.

The purpose of this study was to compare the cumulative efficacy (three treatment sessions) of botulinum toxin A (BTX-A) alone, casting alone, and the combination of BTX-A and casting in the management of dynamic equinus in ambulatory children with spastic cerebral palsy (CP). Thirty-nine children with spastic CP (mean age 5y 10mo, range 3 to 9y) were enrolled in the study. A multicenter, randomized, double blind, placebo-controlled prospective study was used. Children were randomly assigned to one of three treatment groups: BTX-A only (B), placebo injection plus casting (C), or BTX-A plus casting (B+C). The dosage for the BTX-A injections was 4U/kg per extremity. Assessments were performed at baseline, 3, 6, 7.5, and 12 months with a total of three treatments administered after the evaluations at baseline, 3, and 6 months. Primary outcome measures were ankle kinematics, velocity, and stride length. Secondary outcome measures were ankle spasticity, strength, range of motion, and ankle kinetics. Group B made no significant change in any variable at any time. Groups C and B+C demonstrated significant improvements in ankle kinematics, spasticity, passive range of motion, and dorsiflexor strength. Results of this 1-year study indicate that BTX-A alone provided no improvement in the parameters measured in this study, while casting and BTX-A/casting were effective in the short- and long-term management of dynamic equinus in children with spastic CP.

Triceps surae force, length and velocity during walking.

Individuals with neuromuscular conditions may develop muscle contractures that limit joint motion. Decreased muscle length is clinically obvious, but deviations in other functional characteristics of muscle, such as underlying weakness or decreased shortening velocity are more obscure. Therefore, a more comprehensive assessment of muscle characteristics may be required to fully restore function in these individuals. To provide normative comparison data on the force, length and velocity of the triceps surae during walking, 20 adults free from neuromuscular and orthopedic problems were assessed using instrumented gait analysis. Kinematic and kinetic data were used to calculate gastrocnemius and soleus length and velocity, and plantarflexor force during walking. Gastrocnemius length was shortest in early swing and longest in terminal swing and again in midstance. Soleus length was longest throughout the period of single limb stance and was shortest at foot-off. Gastrocnemius shortening velocity was greatest in early swing phase whereas soleus shortening velocity was greatest in pre-swing. Plantarflexor force increased steadily throughout stance phase and peaked in terminal stance at 33.8+/-3.6 N/kg bodyweight. These data provide target levels on the functional parameters of plantarflexor force, length and velocity in order that therapeutic and surgical interventions could be focused on the deviations observed, and the outcomes of these interventions more objectively assessed.

A 2-year follow-up of outcomes following orthopedic surgery or selective dorsal rhizotomy in children with spastic diplegia.

The purpose of this study was to prospectively compare the effect of orthopedic surgery (OS) and selective dorsal rhizotomy (SDR) on muscle tone, range of motion, gait and energy efficiency in ambulatory children with spastic diplegia. Twenty-five children with a diagnosis of spastic diplegia, with a mean age of 73 months, were evaluated prior to surgery and 1 and 2 years postoperatively; however, only the preoperative and 2-year postoperative data are reported here. Eighteen children received SDR and seven received OS. Children were evaluated with the Ashworth scale for muscle tone, passive range of motion (PROM), gait analysis and oxygen consumption for energy cost. Significant improvements were seen in PROM, muscle tone, gait kinematics and oxygen cost regardless of surgical intervention. Although OS and SDR interventions influence motor function through different mechanisms, the gait and energy outcomes 2 years following OS or SDR are similar.

Treatment of spastic diplegia in patients with cerebral palsy: Part II.

This review article describes the evaluation, treatment options, and expected outcomes for many of the common deformities of the lower extremities in patients with cerebral palsy. The evaluation tools including gait analysis will be applied to each specific deformity. Dynamic components are addressed with spasticity management and appropriate muscle and tendon procedures. The static components are treated with bony procedures, including various osteotomies and arthrodesis, incorporating biomechanical principles.

Treatment of spastic diplegia in patients with cerebral palsy.

Appropriate treatment, which includes orthopaedic surgery, physical and occupational therapy, recreational therapy, orthotics, and utilization of assistive devices, will improve the functional outcomes of children with cerebral palsy. Medical modalities such as intramuscular injections of botulinum toxin, and constant intrathecal administration of Baclofen via an implanted pump may also be of benefit. There is a defined set of orthopaedic surgical procedures that can enhance function, and the challenge for the surgeon is to identify which combination of procedures is appropriate for each individual patient and at what point during development to implement them. Some surgeons prefer to wait until patients are older (8-10 years) and perform all of their surgical interventions in one sitting. We, however, favor a different approach wherein surgical procedures are done as indicated during childhood development to enhance function and allow further improvement of motor skills. We refer to this approach as 'Staged Multilevel Interventions in the Lower Extremity' or 'SMILE'. This paper will discuss the rationale for this approach and our recommendations regarding the indications and timing of surgical interventions, as well as techniques and outcomes as reported in the literature.

Selective dorsal rhizotomy versus orthopedic surgery: a multidimensional assessment of outcome efficacy.

OBJECTIVE: To compare the efficacy of selective dorsal rhizotomy (SDR) and orthopedic surgery using multidimensional (National Center for Medical Rehabilitation Research disablement framework) outcome measures. DESIGN: Prospective outcome study. SETTING: Pediatric orthopedic hospital. PARTICIPANTS: Twenty-five children with spastic diplegia. Eighteen participants (mean age, 71.3 mo) chose SDR. Seven participants (mean age, 78.6 mo) chose orthopedic surgery. INTERVENTIONS: Children were evaluated 2 days before surgical intervention and at 6 months, 1 year, and 2 years postsurgically. MAIN OUTCOME MEASURES: The Gross Motor Performance Measure, the Gross Motor Function Measure, and the Pediatric Evaluation of Disability Inventory. RESULTS: The SDR group improved significantly in quality of movement attributes 6 months postsurgically; however, gross motor skills (standing; walking, running, and jumping) gains were seen 2 years postsurgically. The orthopedic group improved significantly in select quality of movement attributes 6 months postsurgically and in standing skills within the first postsurgical year. Self-care skills, mobility, and social function gains were seen earlier and with greater frequency in the SDR group. CONCLUSIONS: Both surgical interventions demonstrated multidimensional benefits for ambulatory children with spastic diplegia. The results suggest that qualitative changes in movement, achieved by spasticity reduction, have a greater effect on the enhancement of functional skill proficiency, thus independence, than recognized.

Stair locomotion in children with spastic hemiplegia: the impact of three different ankle foot orthosis (AFOs) configurations.

The purpose of this study was to investigate the impact of three different ankle foot orthoses (AFO) configurations on the function and kinematics of stair locomotion in children with spastic hemiplegia. Nineteen children were evaluated barefoot and with a hinged, posterior leaf spring (PLS) and solid AFO during stair ascent and descent. Stair specific items from the Pediatric Evaluation of Disability Inventory (PEDI) were used to evaluate function, while a motion measurement system was used to evaluate kinematics. The PEDI revealed no significant differences between AFOs and barefoot, although a greater percentage of children were able to keep up with their peers while wearing a hinged AFO. At the ankle, the hinged AFO provided the greatest amount of dorsiflexion during stance. All AFOs reduced plantarflexion in comparison to barefoot. The results of this study indicate that for children with spastic hemiplegia the use of an AFO did not impair stair ambulation.

Objective measurement of muscle strength in children with spastic diplegia after selective dorsal rhizotomy.

OBJECTIVES: To examine changes in isometric muscle strength at the elbow, knee, and ankle at 6 months and 1 year after selective dorsal rhizotomy (SDR) and to determine if SDR altered the frequency of muscle cocontraction. DESIGN: Prospective outcome study of a consecutive sample. SETTING: Children's hospital. PATIENTS: Ten children with spastic diplegia (7 independent and 3 dependent ambulators who used assistive devices) and 8 age-matched controls. INTERVENTIONS: SDR; physical and occupational therapy; elbow, knee, and ankle measured for flexion and extension strength during three 10-second isometric contractions for each muscle group; and monitored cocontraction measured via muscle electrodes. MAIN OUTCOME MEASURES: Absolute and normalized values of isometric strength; and alterations in the frequency of cocontraction at 6 months and 1 year postoperatively. RESULTS: Children with spastic diplegia showed significantly weaker knee extensors, ankle dorsiflexors, and ankle plantarflexors than age-matched controls. There were no significant differences in strength between the 2 groups in the elbow flexors, elbow extensors, and knee flexors. Isometric strength did not increase or decrease significantly after SDR. Cocontraction during knee extension was normalized after SDR, whereas cocontraction during ankle plantarflexion was unchanged by SDR in the majority of children. CONCLUSION: SDR did not result in a significant decrease in muscle strength in ambulatory children with spastic diplegia. The normalization of the electromyographic patterns at the knee and not the ankle after SDR lends support to the premise that in children with cerebral palsy cocontraction is multifaceted, representing a volitional strategy to enhance control, as well as a disorder of the mechanisms that govern patterns of muscle activity.

Length and force of the gastrocnemius and soleus during gait following tendo Achilles lengthenings in children with equinus.

Nine subjects (12 sides) with cerebral palsy who walked in equnius were evaluated prior to and 1 year after surgical tendo Achilles lengthening. Gastrocnemius and soleus length [Gait Posture, 6 (1997) 9] and plantarflexor force [Gait Posture, 6 (1997) 9; J Biomech, 23 (1990) 495] were calculated. The length of the gastrocnemius and soleus increased significantly (P<0.01) following the intervention. Force output of the triceps surae during push-off increased significantly (13.95 N/kg body weight (BW) preop to 30.31 N/kg BW postop; P<0.01). Assessment of the force-length capacity of the triceps surae in candidates for tendo Achilles lengthenings may identify individuals at risk of residual weakness and iatrogenic crouch.