Susan A. Rethlefsen

Prevalence of specific gait abnormalities in children with cerebral palsy: influence of cerebral palsy subtype, age, and previous surgery.

The authors retrospectively reviewed a series of 492 consecutive cerebral palsy patients undergoing computerized motion analysis. The prevalence of 14 specific gait abnormalities was evaluated and compared based on involvement (hemiplegia, diplegia, or quadriplegia), age, and history of previous surgery (lower extremity orthopaedic surgery or rhizotomy). Stiff knee in swing, equinus, and intoeing were all seen in more than 50% of the subjects in each of the hemiplegic, diplegic, and quadriplegic groups. Increased hip flexion and crouch were also present in more than 50% of the subjects in the diplegic and quadriplegic groups, and hip adduction occurred in more than 50% of the quadriplegic subjects. The likelihood of having stiff knee in swing, out-toeing, calcaneus deformity, and crouch increased with prior surgery. The likelihood of having rotational malalignment of the leg (internal hip rotation with out-toeing), calcaneus, out-toeing, varus and valgus foot deformities, and hip internal rotation increased with age. These findings provide important information for counseling ambulatory children with cerebral palsy and their families.

Cerebral palsy: clinical care and neurological rehabilitation

Cerebral palsy (CP) is defined as motor impairment that limits activity, and is attributed to non-progressive disturbances during brain development in fetuses or infants. The motor disorders of CP are frequently accompanied by impaired cognition, communication, and sensory perception, behavioural abnormalities, seizure disorders, or a combination of these features. CP is thought to affect three to four individuals per 1000 of the general population. The incidence, prevalence, and most common causes of CP have varied over time because of changes in prenatal and paediatric care. Medical management of children and adults involves care from primary-care physicians with input from specialists in neurology, orthopaedics, and rehabilitation medicine. Physicians should also work in conjunction with rehabilitation therapists, educators, nurses, social care providers, and schoolteachers. The focus of rehabilitation treatment has recently shifted to neurological rehabilitation in response to increasing evidence for neuroplasticity. This approach aims to improve development and function by capitalising on the innate capacity of the brain to change and adapt throughout the patients life. As the life expectancy of individuals with CP approaches that of the general population, therapies must be developed that address the needs of adults ageing with disability.

Botulinum Toxin as an Adjunct to Serial Casting Treatment in Children with Cerebral Palsy

BACKGROUND Although botulinum toxin A is frequently used to augment serial casting in the treatment of soft-tissue contractures in children with cerebral palsy, its effectiveness for this purpose has not been evaluated. The purpose of the present study was to determine whether botulinum toxin A injection increases the efficacy of serial casting. METHODS A prospective, randomized trial was undertaken to compare serial casting only with serial casting combined with botulinum toxin A (Botox) injection for the treatment of ankle equinus contractures in twenty-three children with cerebral palsy. Range-of-motion testing, spasticity assessment, and computerized gait analysis were performed as long as twelve months after treatment. RESULTS There was no difference between the groups with regard to the duration of casting required to correct the equinus contracture. Both groups maintained a significant improvement in passive ankle dorsiflexion throughout the follow-up period, although the group managed with casting and Botox had a significant loss of dorsiflexion when the values at six, nine, and twelve months were compared with the value at three months. Peak dorsiflexion during the stance and swing phases was significantly improved in both groups at three months but only in the group managed with casting alone at twelve months. Plantar flexor spasticity was significantly decreased at three months in both groups, but it was significantly decreased at six, nine, and twelve months only in the group managed with casting alone. Spasticity was significantly greater in the group managed with casting and Botox than it was in the group managed with casting only at six, nine, and twelve months. CONCLUSIONS The present study demonstrates the efficacy of serial casting in the treatment of equinus contractures in children with cerebral palsy who are able to walk. Contrary to our hypothesis, the addition of botulinum toxin A to a serial casting regimen led to earlier recurrence of spasticity, contracture, and equinus during gait. The results of the present study suggest that botulinum toxin combined with serial casting for the treatment of fixed contractures will lead to a recurrence of plantar flexor spasticity and equinus contracture by six months in this patient population. While previous research has indicated that the injection of botulinum toxin A is superior to casting for the treatment of dynamic equinus, the present study suggests that serial casting alone is preferable for the treatment of fixed equinus contractures in children with cerebral palsy.

The effects of fixed and articulated ankle-foot orthoses on gait patterns in subjects with cerebral palsy.

Twenty-one subjects with spastic diplegic cerebral palsy were studied to quantify the effects of fixed and articulated ankle-foot orthoses (AFOs) on gait and delineate criteria for their use. Children underwent gait analysis under three conditions, fixed AFOs (FAFOs), articulated AFOs (AAFOs), and shoes alone. Greater dorsiflexion occurred at initial contact with both FAFOs and AAFOs than shoes alone. Dorsiflexion at terminal stance was greatest in AAFOs. Plantarflexor power generation at preswing was preserved in AAFOs. No differences were found in knee position during stance. Knee-extensor strength was positively related to knee extension during stance. No relationships were found between dorsiflexion range of motion, calf spasticity and strength, and peak dorsiflexion during stance. AAFOs are appropriate for subjects with varying degrees of calf spasticity, as long as adequate passive range of motion is available. These findings can be applied primarily to children who do not have a preexisting tendency to crouch.

Comparison of proximal and distal rotational femoral osteotomy in children with cerebral palsy.

This study compares the complication rates and results of 27 proximal (intertrochanteric) and 51 distal femoral rotational osteotomies in 48 patients with static encephalopathy. There was no significant difference between the 14% rate of orthopaedic complications in the intertrochanteric osteotomy (ITO) group and the 10% rate in the distal osteotomy (DO) group. Loss of fixation occurred in three of 51 limbs (6%) in the DO group and in none of 27 limbs in the ITO group. If the results of one surgeon are excluded, fixation loss occurred in one of the 49 remaining DO cases (2%). There was one delayed union in the study population (1/27 limbs [4%] in the ITO group). Of the 33 limbs studied with postoperative gait analysis, overcorrection was present in two limbs (6%): one of 10 limbs (10%) in the ITO group and one of 23 (4%) in the DO group. Static and dynamic measures of femoral rotation improved in both groups, and no statistically significant differences were present between the two groups. Though variable, the mean change in dynamic and static measurements postoperatively was approximately 40% less than the amount of derotation reported at surgery.

Effect of high-frequency, low-magnitude vibration on bone and muscle in children with cerebral palsy.

Background Children with cerebral palsy (CP) have decreased strength, low bone mass, and an increased propensity to fracture. High-frequency, low-magnitude vibration might provide a noninvasive, nonpharmacologic, home–based treatment for these musculoskeletal deficits. The purpose of this study was to examine the effects of this intervention on bone and muscle in children with CP. Methods Thirty-one children with CP ages 6 to 12 years (mean 9.4, SD 1.4) stood on a vibrating platform (30Hz, 0.3 g peak acceleration) at home for 10 min/d for 6 months and on the floor without the platform for another 6 months. The order of vibration and standing was randomized, and outcomes were measured at 0, 6, and 12 months. The outcome measures included computed tomography measurements of vertebral cancellous bone density (CBD) and cross-sectional area, CBD of the proximal tibia, geometric properties of the tibial diaphysis, and dynamometer measurements of plantarflexor strength. They were assessed using mixed model linear regression and Pearson correlation. Results The main difference between vibration and standing was that there was a greater increase in the cortical bone properties (cortical bone area and moments of inertia) during the vibration period (all Ps⩽0.03). There was no difference in cancellous bone or muscle between vibration and standing (all Ps>0.10) and no correlation between compliance and outcome (all rs<0.27; all Ps>0.15). The results did not depend on the order of treatment (P>0.43) and were similar for children in gross motor function classification system (GMFCS) 1 to 2 and GMFCS 3 to 4. Conclusions The primary benefit of the vibration intervention in children with CP was to the cortical bone in the appendicular skeleton. Increased cortical bone area and the structural (strength) properties could translate into a decreased risk of long bone fractures in some patients. More research is needed to corroborate these findings, to elucidate the mechanisms of the intervention, and to determine the most effective age and duration of the treatment. Level of Evidence Level II, prospective randomized cross-over study.

Variability in gait analysis interpretation.

The purpose of this study was to assess the reliability of interpretation of gait analysis data between physicians and institutions. Gait analysis data from seven patients were reviewed by 12 experienced gait laboratory physicians from six institutions. Reviewers identified problems and made treatment recommendations based on the data provided. Agreement among physicians for the most commonly diagnosed problems was slight to moderate (kappa range, 0.14–0.46). Physicians agreed on identification of soft tissue more than bony problems (intraclass correlation, 0.56 vs. 0.37). Variability regarding surgical recommendations for soft-tissue procedures (kappa range, 0.20–0.64) was similar to that for diagnosis of both soft-tissue and bone problems, although recommendation for hamstring lengthening showed substantial agreement (kappa = 0.64). There was less agreement in recommendation of osteotomies (kappa range, 0.13–0.22). Physicians agreed more on the number of soft-tissue procedures than bone procedures recommended (intraclass correlation, 0.65 vs. 0.19). There was an interinstitutional difference in the frequency of soft-tissue (p = 0.0152) and osseous problem identification (p = 0.0002), as well as in the frequency of recommendations for soft-tissue surgery (p = 0.0004) and osteotomies (p < 0.0001). Although gait analysis data are themselves objective, this study demonstrates some subjectivity in their interpretation. The interobserver variability reported here is similar to that reported for established classification systems of various orthopedic conditions.

Outcome of medial versus combined medial and lateral hamstring lengthening surgery in cerebral palsy.

Pre- and postoperative gait analysis and static measurements from 37 children with cerebral palsy who underwent hamstring lengthening were evaluated. Significant improvements in static and kinematic measures were noted after surgery in both groups. Although the differences were not statistically significant, there was a suggestion that combined medial/lateral hamstring lengthening may provide greater improvement in popliteal angle and maximum knee extension in stance. However, there also appears to be a greater risk of knee hyperextension during gait after combined medial and lateral hamstring lengthening than after medial hamstring lengthening alone. Postoperative calf spasticity also appears to be a risk factor for postoperative knee hyperextension. Assessment of calf spasticity may be important in patients undergoing medial and lateral hamstring lengthening. Additional treatments such as bracing and/or botulinum toxin injections to the calf to control equinus and knee hyperextension may be beneficial.

Achilles Tendon Length and Medial Gastrocnemius Architecture in Children With Cerebral Palsy and Equinus Gait

Background The aim of this study was to examine both the tendon and muscle components of the medial gastrocnemius muscle-tendon unit in children with cerebral palsy (CP) and equinus gait, with or without contracture. We also examined a small number of children who had undergone prior surgical lengthening of the triceps surae to address equinus contracture. Methods Ultrasound was used to measure Achilles tendon length and muscle-tendon architectural parameters in children of ages 5 to 12 years. Muscle and tendon parameters were compared among 4 groups: Control group (N=40 limbs from 21 typically developing children), Static Equinus group (N=23 limbs from 15 children with CP and equinus contracture), Dynamic Equinus group (N=12 limbs from 7 children with CP and equinus gait without contracture), and Prior Surgery group (N=10 limbs from 6 children with CP who had prior gastrocnemius recession or tendo-achilles lengthening). The groups were compared using analysis of variance and Scheffe post hoc tests. Results The CP groups had longer Achilles tendons and shorter muscle bellies than the Control group (P<0.001). Normalized tendon length was also longer in the Prior Surgery group compared with the Static Equinus group (P<0.001). The Prior Surgery group had larger pennation angles than the CP groups (P≤0.009) and tended to have shorter muscle fascicle lengths (P≤0.005 compared with Control and Static Equinus, P=0.08 compared with Dynamic Equinus). Similar results were observed for pennation angles and normalized muscle fascicle lengths throughout the range of motion. Conclusions Children with spastic CP and equinus gait have longer-than-normal Achilles tendons and shorter-than-normal muscle bellies. These characteristics are observed even in children with dynamic equinus, before contracture has developed. Surgery further lengthens the tendon, restoring dorsiflexion but not normal muscle-tendon architecture. These architectural features likely affect function, possibly contributing to functional deficits such as plantarflexor weakness after surgery. Level of Evidence Level II, prospective comparative study.

Outcome of hamstring lengthening and distal rectus femoris transfer surgery.

To evaluate the outcome of hamstring lengthening and distal rectus femoris transfer, a retrospective study was performed comparing preoperative and postoperative gait analysis data from 16 children with neurologic involvement. Postoperatively, the timing of peak knee flexion during swing and the total arc of knee motion significantly improved. Hamstring range of motion and knee extension at terminal swing significantly improved, but stride length and gait velocity did not for the overall population. Patients who used braces postoperatively showed an improvement in stride length and velocity when wearing orthoses. This suggests that postoperative bracing may be needed in some patients to maximize the surgical outcome.