Correction of severe crouch gait in patients with spastic diplegia with use of multilevel orthopaedic surgery

ESMAC Best Paper Award 2023: Increased knee flexion in participants with cerebral palsy results in altered stresses at the distal femoral growth plate compared to a typically developing cohort

INTRODUCTION

Femoral deformities are highly prevalent in children with cerebral palsy (CP) and can have a severe impact on patients' gait abilities. While the mechanical stress regime within the distal femoral growth plate remains underexplored, understanding it is crucial given bone's adaptive response to mechanical stimuli. We quantified stresses at the distal femoral growth plate to deepen our understanding of the relationship between healthy and pathological gait patterns, internal loading, and femoral growth patterns.

METHODS

This study included three-dimensional motion capture data and magnetic resonance images of 13 typically developing children and twelve participants with cerebral palsy. Employing a multi-scale mechanobiological approach, integrating musculoskeletal simulations and subject-specific finite element analysis, we investigated the orientation of the distal femoral growth plate and the stresses within it. Limbs of participants with CP were grouped depending on their knee flexion kinematics during stance phase as this potentially changes the stresses induced by knee and patellofemoral joint contact forces.

RESULTS

Despite similar growth plate orientation across groups, significant differences were observed in the shape and distribution of growth values. Higher growth rates were noted in the anterior compartment in CP limbs with high knee flexion while CP limbs with normal knee flexion showed high similarity to the group of healthy participants.

DISCUSSION

Results indicate that the knee flexion angle during the stance phase is of high relevance for typical bone growth at the distal femur. The evaluated growth rates reveal plausible results, as long-term promoted growth in the anterior compartment leads to anterior bending of the femur which was confirmed for the group with high knee flexion through analyses of the femoral geometry. The framework for these multi-scale simulations has been made accessible on GitHub, empowering peers to conduct similar mechanobiological studies. Advancing our understanding of femoral bone development could ultimately support clinical decision-making.

Sagittal spinopelvic alignment in ambulatory persons with cerebral palsy

PURPOSE

This study aimed to describe the spinopelvic alignment of a cohort of young ambulatory individuals with cerebral palsy (CP) and compare it to published spinopelvic alignment data for the typically developing adolescents.

METHODS

Thirty-seven adolescents (18 females) with CP at GMFCS I-III were included in this retrospective case series. Lumbar lordosis and pelvic incidence were measured, and their mismatch was calculated. A model that calculates predicted lumbar lordosis based on pelvic incidence in normative data was utilized to calculate a predicted lumbar lordosis in this cohort with cerebral palsy.

RESULTS

At imaging, ages were mean and standard deviation 13.5 ± 3.0 years. Pelvic incidence was 46.2° ± 12.9°, pelvic tilt was 2.8° ± 9.4°, sacral slope was 43.6° ± 10.8°, and measured lumbar lordosis was 59.4° ± 11.6°. There were no differences in pelvic incidence or lumbar lordosis among the GMFCS levels; however, pelvic incidence was higher in females. Pelvic incidence-lumbar lordosis mismatch greater than 10° was found in 67% of the cohort. Mean predicted lumbar lordosis based on the model was 54.7° ± 8.5°, averaging 8° less than measured lordosis.

CONCLUSION

PI-LL mismatch was identified in 67% of this cohort of ambulatory adolescents with CP, in part due to greater lordosis than predicted by a model based on data from adolescents without CP. The implications of this finding, such as the correlation between sagittal spinopelvic alignment and quality of life in this population, should be assessed further in ambulatory patients with cerebral palsy.

LEVEL OF EVIDENCE

Level IV-retrospective cohort study and literature comparison.

Distal femoral osteotomy and patellar tendon advancement for the treatment of crouch gait in patients with bilateral spastic cerebral palsy

BACKGROUND

Crouch gait, or flexed knee gait, represents a common gait pattern in patients with spastic bilateral cerebral palsy (CP). Distal femoral extension and/or shortening osteotomy (DFEO/DFSO) and patellar tendon advancement (PTA) can be considered as viable options when knee flexion contractures are involved. Better outcomes have been reported after a combination of both, independently of the presence of knee extensor lag. In this study, we evaluated the clinical and kinematic outcomes of these procedures.

PATIENTS AND METHODS

We reviewed a cohort of 52 limbs (28 patients) who were treated for crouch gait by DFEO/DFSO alone (group 1, n = 15) or DFEO/DFSO + PTA (group 2, n = 37) as a part of single event multilevel surgery (SEMLS). The mean age at surgery was 14 years, and the mean follow-up time was 18 months. The physical examination data and three-dimensional standardized gait analysis were collected and analyzed before the surgery and postoperatively.

RESULTS

Overall knee range of motion improved in all limbs. The knee flexion decreased significantly in both groups at initial, mid, and terminal stance. Hip flexion significantly decreased in mid-stance for limbs in group 2. Both clinical and gait parameters were most improved in limbs who underwent DFEO/DFSO + PTA. Increased pelvic tilt was observed in both groups after surgery.

CONCLUSION

Although DFEO/DFSO alone was successful in correcting knee flexion contractures, PTA has helped to improve knee extensor lag and knee extension during gait.

LEVEL OF EVIDENCE

Therapeutic level IV.

The impact of hamstring lengthening on stance knee flexion at skeletal maturity in ambulatory cerebral palsy

This study reports the long-term outcomes of hamstring lengthening to treat flexed knee gait in children with ambulatory cerebral palsy (CP) after skeletal maturity. This retrospective longitudinal observational study used instrumented gait analysis (GA) <8 and >15 years old in children with bilateral CP. The primary variable was knee flexion in stance phase. Eighty children (160 limbs) were included; 49% were male, 51% female. Mean age at first GA was 6.0 (SD: 1.2) years and 19.6 (SD: 4.5) years at final GA. Mean follow-up was 13.7 (SD: 4.7) years. Children were classified as Gross Motor Function Classification System I-8, II-46 and III-26. Average Gross Motor Function Measure Dimension D was 72% (SD: 20%). Hamstring lengthenings occurred once in 82, twice in 54 and three times in 10 limbs. From initial to final GA, average knee flexion in stance was unchanged, 27.8° (SD: 14.8°) to final 27.0° (SD: 11.2°; P = 0.54). Knee flexion at foot contact was 39.6° (SD: 13.0°), improving to final GA of 30.7° (SD: 10.6°; P < 0.001). Initial gait deviation index was 65.8 (SD: 31.9), improving to final 78.9 (SD: 28.2; P < 0.001). Older age, males and concomitant plantar flexor lengthening predicted change toward more flexed knee gait. Hamstring lengthening did not lead to back-kneeing gait at maturity while maintaining childhood stance phase knee flexion. A subgroup still developed significant flexed knee gait posture and may have benefited from more aggressive treatment options. This outcome may also be impacted by diverse functional levels, etiologies and treatments of flexed knee gait.

Quantitative measures of motor development in Angelman syndrome

Angelman Syndrome is a rare neurodevelopmental disorder characterized by developmental delay, lack of speech, seizures, intellectual disability, characteristic behavior, and movement disorders. Clinical gait analysis provides the opportunity for movement quantification to investigate an observed maladaptive change in gait pattern and offers an objective outcome of change. Pressure-sensor-based technology, inertial and activity monitoring, and instrumented gait analysis (IGA) were employed to define motor abnormalities in Angelman syndrome. Temporal-spatial gait parameters of persons with Angelman Syndrome (pwAS) show deficiencies in gait performance through walking speed, step length, step width, and walk ratio. pwAS walk with reduced step lengths, increased step width, and greater variability. Three-dimensional motion kinematics showed increased anterior pelvic tilt, hip flexion, and knee flexion. PwAS have a walk ratio more than two standard deviations below controls. Dynamic electromyography showed prolonged activation of knee extensors, which was associated with a decreased range of motion and the presence of hip flexion contractures. Use of multiple gait tracking modalities revealed that pwAS exhibit a change in gait pattern to a flexed knee gait pattern.  Cross-sectional studies of individuals with AS show a regression toward this maladaptive gait pattern over development in pwAS ages 4-11. PwAS unexpectedly did not have spasticity associated with change in gait pattern. Multiple quantitative measures of motor patterning may offer early biomarkers of gait decline consistent with critical periods of intervention, insight into appropriate management strategies, objective primary outcomes, and early indicators of adverse events.

Surgical Management of Foot and Ankle Deformities in Cerebral Palsy

Children with cerebral palsy (CP) are at a high risk of developing foot and ankle deformities that can impact function, brace/shoe fit, and seating. The 3 commonly observed foot and ankle segmental malalignment patterns include equinus, planovalgus, and equinovarus. Assessment of foot deformities is multifaceted, requiring the collection and integration of data from a combination of sources that include the clinical history, standardized physical examination, observational and quantitative gait analysis, GMFCS classification, and radiographic findings. Surgical procedures are determined by identifying all segmental malalignments and assessing the contribution of dynamic or flexible soft-tissue imbalance, fixed soft-tissue imbalance, and skeletal deformities.

The change in sagittal plane gait patterns from childhood to maturity in bilateral cerebral palsy

BACKGROUND

The longitudinal stability of sagittal gait patterns in diplegic cerebral palsy (CP), stratified using the Rodda classification, is currently unknown.

RESEARCH QUESTION

What is the trajectory of sagittal plane gait deformities as defined by the Rodda classification in a large cohort treated with orthopedic surgery guided by gait analysis?

METHODS

A retrospective study utilized gait analysis to evaluate sagittal gait parameters before age 8 and after age 15 years. Individual limbs were categorized at each time point according to the Rodda classification based on mean sagittal plane knee and ankle angle during stance. Welch's t-tests compared gait variables from early childhood with maturity and examined changes associated with plantarflexor lengthening surgery.

RESULTS

100 youth with CP were evaluated twice: at a mean age of 5.49 ± 1.18 and 19.09 ± 4.32 years, respectively. Gross Motor Function Classification System distribution at maturity was I (10.5 %), II (55.2 %), III (28.6 %), and IV (5.7 %). At the initial visit, most limbs were in either true equinus (30 %) or jump-knee gait (26.5 %). At maturity, crouch gait (52.5 %) was the most common classification, of which 47.6 % were mild (1-3 standard deviations from age-matched norm; 21°-30°) and 52.4 % moderate or severe. For the entire cohort, at initial and final visits, respectively, mean knee flexion in stance was 26.8°±14.8° and 25.9°±11.4° (p = 0.320), ankle dorsiflexion in stance increased from -0.3°±11.5° to 9.0°±6.0° (p < 0.001), and passive knee flexion contracture was -2.3°±7.0° and -3.9°±8.0° (p = 0.043). In children who started in true equinus, apparent equinus, and crouch, there was no difference in stance phase knee flexion at maturity between those who underwent plantarflexor lengthenings versus those who did not (p > 0.18).

SIGNIFICANCE

The trend in this cohort was toward crouch with increased stance phase ankle dorsiflexion from early childhood to maturity. Plantarflexor lengthenings were not a significant factor in the progression of stance phase knee flexion.

Knee flexion contracture impacts functional mobility in children with cerebral palsy with various degree of involvement: a cross-sectional register study of 2,838 individuals

Background and purpose - The impact of knee flexion contracture (KFC) on function in cerebral palsy (CP) is not clear. We studied KFC, functional mobility, and their association in children with CP.Subjects and methods - From the Swedish national CP register, 2,838 children were defined into 3 groups: no (≤ 4°), mild (5-14°), and severe (≥ 15°) KFC on physical examination. The Functional Mobility Scale (FMS) levels were categorized: using wheelchair (level 1), using assistive devices (level 2-4), walking independently (level 5-6). Standing and transfer ability and Gross Motor Function Classification (GMFCS) were assessed.Results - Of the 2,838 children, 73% had no, 14% mild, and 13% severe KFC. KFC increased from 7% at GMFCS level I to 71% at level V. FMS assessment (n = 2,838) revealed around 2/3 were walking independently and 1/3 used a wheelchair. With mild KFC (no KFC as reference), the odds ratio for FMS level 1 versus FMS level 5-6 at distances of 5, 50, and 500 meters, was 9, 9, and 8 respectively. Correspondingly, with severe KFC, the odds ratio was 170, 260, and 217. In no, mild, and severe KFC 14%, 47%, and 77% could stand with support and 11%, 25%, and 33% could transfer with support.Interpretation - Knee flexion contracture is common in children with CP and the severity of KFC impacts function. The proportion of children with KFC rose with increased GMFCS level, reduced functional mobility, and decreased standing and transfer ability. Therefore, early identification and adequate treatment of progressive KFC is important.

The influence of preoperative knee flexion contracture severity on short-term outcome of orthopedic surgery in ambulatory children with bilateral cerebral palsy

BACKGROUND

Indications and cutoff value of deformities to determine surgical procedures for flexed knee gait are not clear. The aim was to determine the influence of none or mild, and moderate preoperative knee flexion contracture on the improvement of gait after orthopedic surgery in children with bilateral cerebral palsy (CP).

METHODS

Inclusion criteria; bilateral CP, Gross Motor Function Classification System level I-III, and pre- and post operative-gait analysis. The 132 individuals identified were categorized into 2 groups based on the severity of knee flexion contracture (group 1: none or less than 11°; group 2: greater than or equal to 11°), and then matched according to the exact same soft tissue and/or bony orthopedic surgical procedures performed. The indication for surgery was to prevent progressive development of knee flexion contracture and stance phase flexed knee gait. Pre- and postoperative physical examination and gait analysis data were analyzed retrospectively.

RESULTS

Sixty (30 + 30) children, with mean age 10.6 years in each group, were included. The average follow-up time was 17 months. Gait Deviation Index (GDI) improved in group 1 from mean 66 (SD 19) to 74 (15), p = 0.004, and in group 2 from 60 (13) to 69 (15), p = 0.001. Knee flexion in stance improved in group 1 from 21.4 (16.1) to 12.1 (16.0) degrees, p = 0.002, and in group 2 from 32.2 (14.2) to 17.0 (15.9), p = 0.001. Step length improved in both groups, p = 0.017 and p = 0.008, respectively. Only in group 2 significant improvement was noted in walking speed, p = 0.018 and standing function, Gross Motor Function Measure (GMFM-D), p = 0.001. Knee flexion contracture decreased in group 1 from mean 4.6 (5.3) to 2.1 (8.3) degrees, p = 0.071 and in group 2 from 17.2 (4.9) to 9.6 (9.3), p = 0.001. There was no statistical difference between groups in pre-post improvement of GDI or other variables, except GMFM-D.

CONCLUSIONS

Relative mild to moderate preoperative knee flexion contracture does not influence the short-term improvement of gait after orthopedic surgery in children with bilateral CP.

Toward a hybrid exoskeleton for crouch gait in children with cerebral palsy: neuromuscular electrical stimulation for improved knee extension

BACKGROUND

Neuromuscular Electrical Stimulation (NMES) has been utilized for many years in cerebral palsy (CP) with limited success despite its inherent potential for improving muscle size and/or strength, inhibiting or reducing spasticity, and enhancing motor performance during functional activities such as gait. While surface NMES has been shown to successfully improve foot drop in CP and stroke, correction of more complex gait abnormalities in CP such as flexed knee (crouch) gait remains challenging due to the level of stimulation needed for the quadriceps muscles that must be balanced with patient tolerability and the ability to deliver NMES assistance at precise times within a gait cycle.

METHODS

This paper outlines the design and evaluation of a custom, noninvasive NMES system that can trigger and adjust electrical stimulation in real-time. Further, this study demonstrates feasibility of one possible application for this digitally-controlled NMES system as a component of a pediatric robotic exoskeleton to provide on-demand stimulation to leg muscles within specific phases of the gait cycle for those with CP and other neurological disorders who still have lower limb sensation and volitional control. A graphical user interface was developed to digitally set stimulation parameters (amplitude, pulse width, and frequency), timing, and intensity during walking. Benchtop testing characterized system delay and power output. System performance was investigated during a single session that consisted of four overground walking conditions in a 15-year-old male with bilateral spastic CP, GMFCS Level III: (1) his current Ankle-Foot Orthosis (AFO); (2) unassisted Exoskeleton; (3) NMES of the vastus lateralis; and (4) NMES of the vastus lateralis and rectus femoris. We hypothesized in this participant with crouch gait that NMES triggered with low latency to knee extensor muscles during stance would have a modest but positive effect on knee extension during stance.

RESULTS

The system delivers four channels of NMES with average delays of 16.5 ± 13.5 ms. Walking results show NMES to the vastus lateralis and rectus femoris during stance immediately improved mean peak knee extension during mid-stance (p = 0.003*) and total knee excursion (p = 0.009*) in the more affected leg. The electrical design, microcontroller software and graphical user interface developed here are included as open source material to facilitate additional research into digitally-controlled surface stimulation ( github.com/NIHFAB/NMES ).

CONCLUSIONS

The custom, digitally-controlled NMES system can reliably trigger electrical stimulation with low latency. Precisely timed delivery of electrical stimulation to the quadriceps is a promising treatment for crouch. Our ultimate goal is to synchronize NMES with robotic knee extension assistance to create a hybrid NMES-exoskeleton device for gait rehabilitation in children with flexed knee gait from CP as well as from other pediatric disorders.

TRIAL REGISTRATION

clinicaltrials.gov, ID: NCT01961557 . Registered 11 October 2013; Last Updated 27 January 2020.

What is the functional mobility and quality of life in patients with cerebral palsy following single-event multilevel surgery?

PURPOSE

To report functional mobility in patients with diplegic cerebral palsy (CP) at long-term follow-up after single-event multilevel surgery (SEMLS). The secondary aim was to assess the relationship between functional mobility and quality of life (QoL) in patients previously treated with SEMLS.

METHODS

A total of 61 patients with diplegic CP, mean age at surgery 11 years, eight months (sd 2 years, 5 months), were included. A mean of eight years (sd 3 years, 10 months) after SEMLS, patients were contacted and asked to complete the Functional Mobility Scale (FMS) questionnaire over the telephone and given a weblink to complete an online version of the CP QOL Teen. FMS was recorded for all patients and CP QOL Teen for 23 patients (38%).

RESULTS

Of patients graded Gross Motor Function Classification System (GMFCS) I and II preoperatively, at long-term follow-up the proportion walking independently at home, school/work and in the community was 71% (20/28), 57% (16/28) and 57% (16/28), respectively. Of patients graded GMFCS III preoperatively, at long-term follow-up 82% (27/33) and 76% (25/33) were walking either independently or with an assistive device at home and school/work, respectively, while over community distances 61% (20/33) required a wheelchair. The only significant association between QoL and functional mobility was better 'feelings about function' in patients with better home FMS scores (r = 0.55; 95% confidence interval 0.15 to 0.79; p = 0.01).

CONCLUSION

The majority of children maintained their preoperative level of functional mobility at long-term follow-up after SEMLS.

LEVEL OF EVIDENCE

IV.

Distal Femoral Shortening Osteotomy for Severe Knee Flexion Contracture and Crouch Gait in Cerebral Palsy

Although there have been advancements of surgical techniques to correct gait abnormalities seen in patients with cerebral palsy, the crouch gait remains one of the most difficult problems to treat. The purpose of this retrospective study was to examine our results of distal femoral shortening osteotomy (DFSO) and patellar tendon advancement (PTA), performed in patients with crouch gait associated with severe knee flexion contracture. A total of 33 patients with a mean fixed knee contracture of 38° were included in the study. The mean age at the time of surgery was 12.2 years and the mean follow-up was 26.9 months. The measurements of clinical, radiological, and gait parameters were performed before and after surgery. The mean degrees of knee flexion contracture, Koshino index of patella height, and Gait Deviation Index were found to be significantly improved at the time of final follow-up. The maximum knee extension during the stance phase improved by an average of 25°, and the range of knee motion during gait increased postoperatively. On the other hand, the mean anterior pelvic tilt increased by 9.9°. Also, the maximum knee flexion during the swing phase decreased and the timing of peak knee flexion was observed to be delayed. We conclude that combined procedure of DFSO and PTA is an effective and safe surgical method for treating severe knee flexion contracture and crouch gait. However, the surgeons should be aware of the development of increased anterior pelvic tilt and stiff knee gait after the index operation.

Long-term muscle changes after hamstring lengthening in children with bilateral cerebral palsy

AIM

To evaluate short-term (1y postoperatively; E1) and long-term (at least 4y postoperatively; E2) changes in hamstring muscle-tendon length (MTL) and lengthening velocity after hamstring lengthening in children with bilateral cerebral palsy (CP).

METHOD

Three-dimensional gait analysis was performed in 19 children (16 males, 3 females; 36 limbs; mean age at surgery 9y [SD 3y]; range 6-10y) with flexed knee gait, preoperative ankle dorsiflexion lower than 20 degrees, and CP before bilateral hamstring lengthening (E0), at E1 and E2. Hamstring MTL (normalized by leg length) and velocity were assessed via OpenSim software.

RESULTS

MTL increased from E0 to E1 (p=0.004) and decreased from E1 to E2 (p<0.020). Hamstring lengthening velocity did not change. In the subgroup with short, not slow hamstrings, the increase in MTL was maintained at E2.

INTERPRETATION

Hamstring lengthening is an efficient procedure to lengthen short and/or slow hamstrings short-term. The desired outcome with maintenance of the postoperative changes in hamstring MTL is only achieved for preoperatively short, not slow hamstrings.

WHAT THIS PAPER ADDS

Surgical hamstring lengthening can be confirmed via musculoskeletal modelling in OpenSim software. Surgical hamstring lengthening in cerebral palsy does not change hamstring lengthening velocity. Short, not slow hamstrings present a long-lasting muscle-tendon length (MTL) increase after hamstring lengthening. Changes in MTL after hamstring lengthening cannot be maintained for slow hamstrings. MTL does not change after hamstring lengthening for neither short nor slow hamstrings.

Quantifying the velocity-dependent muscle response during gait of children with Cerebral Palsy

A new method is introduced quantifying the velocity-dependent muscle response during gait in spastic muscles of children with Cerebral Palsy. The velocity-dependent muscle activation Index is calculated during a 3-dimensional gait analysis using segment angular velocity and the Instantaneous Mean Frequency calculated from surface electromyography. Typical developed children (n = 11) and children with hemiplegia (n = 11) aging from 8 to 19 years participated in the study. The rectus femoris and the medial gastrocnemius were assessed by calculating the velocity dependent muscle activation Index and the modified Ashworth Scale. Greater velocity-dependent muscle activation Index values for both medial gastrocnemius and rectus femoris muscles were associated with greater Ashworth Scale. Post hoc analysis revealed significant lower velocity-dependent muscle activation Index means in the Typical developed group compared with Ashworth Scale scores of 1, 2, 3, and 5. In addition, velocity-dependent muscle activation Index for Ashworth Scale 0, 1, and 2 were significantly lower than for Ashworth Scale 3 and 5. The velocity dependent muscle activation Index showed negative low correlation with walking speed and cadence. Findings show that spastic muscles can be quantified during dynamic functional task such as walking. Future studies should investigate the reliability of the velocity-dependent muscle activation Index that may be used for the assessment of spasticity management such as Botulinum toxin A interventions.

Use of 3D gait analysis as predictor of Achilles tendon lengthening surgery outcomes in children with cerebral palsy

BACKGROUND

In children with spastic cerebral palsy (CP), the treatment of equinus foot with Achilles tendon lengthening (ATL) surgery is associated with high incidence of overcorrection, which may result in crouch gait.

AIM

We aimed to assess if gait pattern in preoperative time could be a predictor of the surgery outcome.

DESIGN

Cross-sectional retrospective study.

SETTING

Movement Analysis Lab of IRCCS San Raffaele Pisana Hospital in Rome (Italy).

POPULATION

Eighteen children (mean age 9.6±4.7 years) with spastic diplegia CP who underwent bilateral ATL surgery to correct equinus foot were involved.

METHODS

Participants underwent 3D gait analysis before and approximately 12 months after surgery. Primary measures were spatiotemporal, kinematic (summarized by Gait Variable Scores, GVSs) and kinetic parameters. The gait patterns for each leg was defined from kinematic data, using a quantitative classification: plantar flexor knee extension (PFKE) index. The CP group was split into true equinus and jump gait.

RESULTS

The equinus foot was successfully corrected as demonstrated by the improvement of GVS ankle dorsi-plantarflexion. However, there was a high rate of overcorrection in the true equinus, characterized by increases in knee flexion-extension GVS (8.7° pre vs. 16.7° post P<0.05) and knee flexion angle at initial contact (5.2° vs. 20.6° P<0.05) and by a decrease in the maximum ankle power generated at push-off (1.49 vs. 0.83 W/kg P<0.05).

CONCLUSIONS

Assessment of motor phenotype in preoperative time are good predictors of the results of ATL surgery. In children with true equinus gait, the increase of knee flexion subsequent to ATL is an early indicator that this technique will lead to crouch gait. These results show the influence of true equinus and jump gait patterns on the outcomes of the ATL.

CLINICAL REHABILITATION IMPACT

Therefore, we propose that this approach could have clinical value to evaluate and prescribe rehabilitation in children with CP disease, proposing different solutions depending on motor phenotype.

Multilevel Surgery for Children With Cerebral Palsy: A Meta-analysis

CONTEXT

Multilevel surgery (MLS) is standard care for reducing musculoskeletal disorders among children with spastic cerebral palsy (CP).

OBJECTIVE

To summarize the literature examining effects of MLS and satisfaction with MLS for children with CP.

DATA SOURCES

Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials were searched.

STUDY SELECTION

Studies in which authors reported effects of or satisfaction with MLS in children with CP were selected.

DATA EXTRACTION

Two authors screened and extracted data on gross motor function, gait speed, gait (eg, Gait Profile Score), range of motion, strength, spasticity, participation, quality of life, satisfaction, and adverse events.

RESULTS

Seventy-four studies (3551 participants) were identified. One was a randomized controlled trial (RCT) (n = 19); the remainder were cohort studies. Pooled analysis of cohort studies revealed that MLS did not have a long-term effect on gross motor function (standardized mean difference [SMD]: 0.38; 95% confidence interval [CI]: -0.25 to 1.01) or gait speed (SMD: 0.12; 95% CI: -0.01 to 0.25) but did improve gait (SMD: -0.80; 95% CI: -0.95 to -0.65). The RCT also revealed no effect of MLS on gross motor function but improvements in the Gait Profile Score at 1 year. Participation and quality of life were reported in only 5 studies, and adverse events were adequately reported in 17 studies.

LIMITATIONS

Data were largely from cohort studies.

CONCLUSIONS

Findings reveal that gait, but not gross motor function, improves after MLS. RCTs and improved reporting of studies of MLS are required.

Clinical Examination of Children with Cerebral Palsy

Cerebral palsy (CP), a heterogeneous disorder of movement and posture, is one of the most important causes of disability affecting children. With a wide variability in the clinical presentation and a paucity of reliable diagnostic tests, decision-making in CP is fraught with difficulties and challenges. The plethora of musculoskeletal manifestations includes poor muscle function, spasticity, rigidity, muscle weakness, poor selective motor control, soft-tissue and joint contractures, torsional malalignments, and lever arm dysfunctions. Children with CP are at a high risk of further worsening and progression of these musculoskeletal abnormalities with the natural course of the disease. A comprehensive assessment that includes a combination of detailed medical history, functional assessment, clinical examination, analysis of gait, and radiological assessment is required to provide a favorable treatment outcome in these children. A close surveillance is essential so as to identify risk factors for the development and progression of musculoskeletal problems so that early interventions can be carried out to circumvent them. This review article is to highlight the importance of clinical examination in the assessment of children with CP.

Management of the Knee Problems in Spastic Cerebral Palsy

Two common knee problems in cerebral palsy are increased knee flexion during stance phase and reduced knee flexion during the swing phase of gait. We reviewed the recent literature and based on that, we formed this review. Hamstring spasticity, quadriceps weakness, soleus weakness, and lever-arm dysfunction are few factors which lead to increased knee flexion during stance phase. Rectus spasticity diminishes knee flexion in the swing. Resulting gait-stiff knee gait interferes with ground clearance. Both gait patterns result into esthetically poor gait and increased energy consumption. Knee flexion gait may lead to pain in the knee. Natural history of knee flexion gait suggests deterioration over time. In the early stage, these gait abnormalities are managed by nonoperative treatment. Cases in which nonoperative measures fail or advance cases need surgical treatment. Various variables which are taken into consideration before selecting a particular treatment option are described. We also present an algorithm for decision-making. Nonsurgical options and surgical procedures are discussed.

Distal Femoral Extension Osteotomy with 90° Pediatric Condylar Locking Compression Plate and Patellar Tendon Advancement for the Correction of Crouch Gait in Cerebral Palsy

BACKGROUND

Various treatment modalities are available for the correction of crouch gait, ranging from hamstring lengthening to a combination of soft-tissue and bony procedures. We report the results of distal femoral extension osteotomy (DFEO) fixed with 90° pediatric condylar locking compression plate (LCP) and patellar tendon advancement (PTA) for crouch gait in children with cerebral palsy.

MATERIALS AND METHODS

A total of 26 patients (52 knees) with a mean age of 14.36 years (range 11.6-20 years) who presented with crouch gait were treated with DFEO and PTA. Patients were analyzed prospectively using clinical (knee flexion deformity, knee range of motion, extensor lag), functional (modified Ashworth, Tardieu scores, muscle strength, gross motor functional classification system [GMFCS], functional mobility scale [FMS], gross motor functional measure [GMFM]) and radiological (Koshino Index) outcome measures and followed up at a mean of 22 months (range 12-53 months).

RESULTS

There was an improvement in all outcome measures postoperatively, with improved function and independence. The mean knee flexion deformity improved significantly from 20.7° ± 6.59 to 0.67° ± 2.62, mean muscle strength of quadriceps improved from 3.01 ± 0.5 to 3.5 ± 0.54 and mean extensor lag improved from 20° ± 7.14 to 4.13° ± 4.16. The mean Koshino Index improved from 1.4 ± 0.16 to 1.0 ± 0.08. The mean GMFM-D improved from 15.58 ± 6.2 to 26.31 ± 5.8 and mean FMS for 5 m improved from 2.9 ± 1.09 to 3.6 ± 0.84, indicating significant improvement in household ambulation. There were four complications; transient peroneal nerve palsy in 3 patients, which recovered completely and 1 superficial wound dehiscence. There was no loss of fixation, tendon pull-out or deep infection.

CONCLUSION

The combined procedure of DFEO and PTA can correct knee flexion deformity, restore knee extensor strength, and improve function in patients with crouch gait. The pediatric condylar LCP provides stable fixation to allow early mobilization and faster rehabilitation.

Predictors affecting outcome after single-event multilevel surgery in children with cerebral palsy: a systematic review

AIM

To review the potential predictors of outcome after single-event multilevel surgery (SEMLS) in children with cerebral palsy (CP).

METHOD

A literature search using the following criteria was performed in six electronic databases: (1) children with cerebral palsy; (2) analysed potential predictors of outcome after SEMLS; (3) minimum 12 months follow-up. The potential predictors were predefined: sex; topographical distribution; socio-economic status; Gross Motor Function Classification System (GMFCS) level; preoperative kinematic summary statistic; age at surgery. Study quality was appraised with the methodological index for non-randomized studies (MINORS) and the Oxford Centre for Evidence-Based Medicine scale.

RESULTS

Of the seven studies identified, the MINORS scores ranged from 9 to 11 and all were graded 2b on the Oxford Centre for Evidence-Based Medicine scale. There was little or no evidence to support sex, topographical distribution, or socio-economic status as predictive factors after SEMLS. Preoperative Gait Profile Score (GPS) was the best measure of expected improvement in gait kinematics. Parent-reported satisfaction and GPS were best after SEMLS in children graded GMFCS II. The best long-term results were seen in those aged between 10 years and 12 years of age.

INTERPRETATION

The candidate who might expect to realize the most improvement from SEMLS is aged between 10 years and 12 years, is in GMFCS level II, and has a poor preoperative GPS.

WHAT THIS PAPER ADDS

Children aged 10 to 12 years, in Gross Motor Function Classification System level II, with a poor preoperative Gait Profile Score might expect to realize the most improvement after single-event multilevel surgery.

Mid-term development of hamstring tendon length and velocity after distal femoral extension osteotomy in children with bilateral cerebral palsy: a retrospective cohort study

AIM

Flexed knee gait can be treated with distal femoral extension osteotomy (DFEO) and additional patellar tendon advancement (PTA) in children with cerebral palsy (CP). This study assesses changes in hamstring muscle tendon length (MTL) and velocity after DFEO (+PTA).

METHOD

Nineteen children (mean age 13y [standard deviation 3y] at surgery) with CP and flexed knee gait who were treated with DFEO (15 limbs) or DFEO+PTA (10 limbs) were retrospectively included in this study. Gait analyses were performed preoperatively (E0), 1 year postoperatively (E1), and for 10 limbs additionally 2 to 5 years postoperatively (E2). Hamstring MTL and velocities were assessed at all examination dates using OpenSim.

RESULTS

Hamstring MTL and velocity did not change significantly over time. From E0 to E1, knee flexion in stance improved for both DFEO and DFEO+PTA (p<0.05), knee flexion in swing only improved after DFEO+PTA (p<0.05). The improved knee flexion in stance and swing was maintained at E2.

INTERPRETATION

DFEO led to a significant improvement in knee kinematics at E1 which was maintained at E2. DFEO seems to prevent recurrent hamstring tightness but does not lead to lengthened or fastened hamstrings.

WHAT THIS PAPER ADDS

Distal femoral extension osteotomy (DFEO) does not change hamstring muscle tendon length. DFEO does not change hamstring lengthening velocity. DFEO leads to a significant improvement in knee kinematics. Changes in knee kinematics after DFEO can be maintained at mid-term. DFEO seems to prevent recurrent hamstring tightness.

Retrospective Evaluation of Changes in Gait Patterns in Children and Adolescents With Cerebral Palsy After Multilevel Surgery

The purpose of this study was to retrospectively investigate changes in gait patterns after single-event multilevel surgery in children and adolescents with bilateral cerebral palsy. Three-dimensional instrumented pre- and postoperative gait data of 12 patients were compared to data of 12 healthy control subjects using principal component analysis to reduce the dimensionality of kinematic and kinetic gait data and detect gait differences. The differences between pre- and postoperative data and between postoperative data and data of control subjects were calculated using a linear mixed model. The results revealed 14 significant effects for pre- and postoperative waveforms and 11 significant effects for postoperative and control waveforms. Patients after single-event multilevel surgery walked with smaller internal foot progression angle throughout the gait cycle, lower knee flexion at initial swing, and earlier knee extension during terminal swing. Retained gait deviations included excessive pelvic tilt and internally rotated and flexed hips over the entire gait cycle. Contrary to our hypothesis, postoperative waveforms in the sagittal plane differed more from control waveforms than from preoperative waveforms. These results emphasize the importance of carefully planning further conservative therapy 2 years after single-event multilevel surgery.

Influence of surgery involving tendons around the knee joint on ankle motion during gait in patients with cerebral palsy

Background

Simultaneous motion of the knee and ankle joints is required for many activities including gait. We aimed to evaluate the influence of surgery involving tendons around the knee on ankle motion during gait in the sagittal plane in cerebral palsy patients.

Methods

We included data from 55 limbs in 34 patients with spastic cerebral palsy. Patients were followed up after undergoing only distal hamstring lengthening with or without additional rectus femoris transfer. The patients’ mean age at the time of knee surgery was 11.2 ± 4.7 years, and the mean follow-up duration was 2.2 ± 1.5 years (range, 0.9–6.0 years). Pre- and postoperative kinematic variables that were extracted from three-dimensional gait analyses were then compared to assess changes in ankle motion after knee surgery. Outcome measures included ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle. Various sagittal plane knee kinematics were also measured and used to predict ankle kinematics. A linear mixed model was constructed to estimate changes in ankle motion after adjusting for multiple factors.

Results

Improvement in total range of motion of the knee resulted in improved motion of the ankle joint. We estimated that after knee surgery, ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle decreased, respectively, by 0.4° (p = 0.016), 0.6° (p < 0.001), 0.2° (p = 0.038), and 0.5° (p = 0.006) per degree increase in total range of motion of the knee after either knee surgery. Furthermore, dynamic range of motion of the ankle increased by 0.4° per degree increase in postoperative peak knee flexion during swing.

Conclusions

Improvement in total knee range of motion was found to be correlated with improvement in ankle kinematics after surgery involving tendons around the knee. As motion of the knee and ankle joints is cross-linked, surgeons should be aware of potential changes in the ankle joint after knee surgery.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2003-0) contains supplementary material, which is available to authorized users.

Does additional patella tendon shortening influence the effects of multilevel surgery to correct flexed knee gait in cerebral palsy: A randomized controlled trial

BACKGROUND

The aims of this study were to investigate if patellar tendon shortening (PTS) as a part of SEMLS (single event multilevel surgery) is effective for reduction of flexed knee gait in children with cerebral palsy (CP) and, if PTS leads to stiff knee gait.

METHODS

In a randomized controlled study 22 children with flexed knee gait (age: 10.4 ± 2.6 years, GMFCS Level I-III) were randomized and allocated to two groups (1: SEMLS + PTS; 2: SEMLS no PTS): SEMLS was performed for correction of flexed knee gait either with or without additional PTS. Before and after surgery (follow up: 12.7 ± 1.6 months) kinematics (3-D motion analysis) and clinical parameters were compared.

RESULTS

Two children were lost to follow up. Maximum knee extension improved significantly in both groups after SEMLS while the patients with additional PTS showed much more correction (SEMLS + PTS: 37.6° to 11.4°, p = 0.007; SEMLS no PTS: 35.1° to 21.8°, p = 0.016). After surgery peak knee flexion decreased significantly (14.6°, p = 0.004) in the "SEMLS + PTS" group while there was no relevant change in the other group. There was a trend of increase in anterior pelvic tilt after surgery in both groups, but no statistical significant difference. After surgery knee flexion contracture (15.9°, p < 0.001) and popliteal angle (27.2, p = 0.009) measured on clinical examination only decreased significantly in the "SEMLS + PTS" group.

CONCLUSION

PTS is effective for correction of flexed knee gait and knee flexion contracture leading to superior stance phase knee extension. However, additional PTS may lead to stiff knee gait and a higher increase of anterior pelvic tilt.

Does patella lowering improve crouch gait in cerebral palsy? Comparative retrospective study

BACKGROUND

Patella lowering aims to improve quadriceps function as a means of correcting crouch gait in patients with cerebral palsy. Few studies have assessed the effects of patella lowering as a component of multilevel surgery.

HYPOTHESIS

Including patella lowering into the components of multilevel surgery is beneficial in patients with crouch gait and patella alta.

MATERIAL AND METHODS

In 12 lower limbs with patella alta (Caton-Deschamps index>1.4) in 41 children with cerebral palsy, patella lowering was performed, without distal femoral extension osteotomy or hamstring release. Among limbs with similar surgical procedures (e.g., hamstring lengthening, rectus femoris transfer) except for patella lowering, controls were selected retrospectively by matching on a propensity score for patella lowering. The propensity score was computed based on preoperative knee flexion contracture, knee extension lag, and minimum knee flexion at mid-stance. Clinical and 3D kinematic data were compared between the two groups.

RESULTS

The improvement in minimum knee flexion at mid-stance was significantly greater in the group with patellar lowering (-24°±12°vs. -12°±7°). The Gait Deviation Index improved similarly in the two groups. Knee flexion contracture improved only in the group with patellar lowering. Extension lag did not improve in either group. Peak knee flexion during the swing phase remained unchanged in both groups.

DISCUSSION

Patellar lowering is effective in diminishing minimum knee flexion at mid-stance in patients with patella alta and crouch gait due to cerebral palsy. Patellar lowering has not adverse effects on gait. These findings cannot be assumed to apply to patients with normal patellar height.

LEVEL OF EVIDENCE

IV (retrospective study).

Distal femoral extension and shortening osteotomy as a part of multilevel surgery in children with cerebral palsy

BACKGROUND

There are several reports describing an increase in anterior pelvic tilt after hamstring lengthening in children with cerebral palsy (CP). Distal femoral extension and shortening osteotomy (DFESO) is an alternative treatment for correction of flexed knee gait, but investigations analyzing outcome and influence on adjacent joint are few in the literature. The purpose of this study was to analyze the influence of DFESO on knee and pelvis in children with CP. Furthermore, it was of interest if an additional patellar tendon advancement (PA) influences outcome.

METHODS

In this retrospective study, 31 limbs of 22 children (GMFCS I-III; mean age: 12.1±3.1 years), who received DFESO were included and kinematic parameters (knee, pelvis) measured by 3-D-gait analysis were compared before and at least 1 year after surgery (mean follow-up period: 15.6 months).

RESULTS

After surgery, during stance phase minimum knee flexion improved significantly by 20.5° (P<0.001) and mean anterior pelvic tilt increased by 4.0 degrees (P=0.045). In 16 limbs, the postoperative increase in maximum anterior pelvic tilt was more than 5°. Limbs who received an additional PA showed the biggest increase in anterior pelvic tilt.

CONCLUSIONS

DFESO is an effective method for correction of flexed knee gait in children with CP. Furthermore, the results of this study indicate that DFESO may lead to an increase in anterior pelvic tilt, which may lead to a recurrence of flexed knee gait. In this context, PA seemed to aggravate the effect on the pelvis.

Effectiveness of surgical and non-surgical management of crouch gait in cerebral palsy: A systematic review

BACKGROUND

Cerebral palsy (CP) is a prevalent group of neuromotor disorders caused by early injury to brain regions or pathways that control movement. Patients with CP exhibit a range of functional motor disabilities and pathologic gait patterns. Crouch gait, characterized by increased knee flexion throughout stance, is a common gait pattern in CP that increases energy costs of walking and contributes to ambulatory decline. Our aim was to perform the first systematic literature review on the effectiveness of interventions utilized to ameliorate crouch gait in CP.

METHODS

Comprehensive searches of five medical databases yielded 38 papers with 30 focused on orthopaedic management.

RESULTS

Evidence supports the use of initial hamstring lengthenings and rectus femoris transfers, where indicated, for improving objective gait measures with limited data on improving gait speed or gross motor function. In contrast, evidence argues against hamstring transfers and revision hamstring lengthening, with recent interest in more technically demanding corrective procedures. Only eight studies evaluated alternatives to surgery, specifically strength training, botulinum toxin or orthoses, with inconsistent and/or short-lived results.

CONCLUSIONS

Although crouch in CP is recognized clinically as a complex multi-joint, multi-planar gait disorder, this review largely failed to identify interventions beyond those which directly address sagittal plane knee motion, indicating a major knowledge gap. Quality of existing data was notably weak, with few studies properly controlled or adequately sized. Outcomes from specific procedures are confounded by multilevel surgeries. Successful longer term strategies to prevent worsening of crouch and subsequent functional decline are needed.

LEVEL OF EVIDENCE

Systematic review.

Orthopedic surgery in cerebral palsy: Instructional course lecture

Orthopedic surgery (OS) plays an important role in the management of cerebral palsy (CP). The objectives of OS are to optimize functions and prevent deformity. Newer developments in OS for CP include emphasis on hip surveillance, minimally invasive procedures, use of external fixators instead of plates and screws, better understanding of lever arm dysfunctions (that can only be corrected by bony OS), orthopedic selective spasticity-control surgery, and single-event multilevel lever arm restoration and anti spasticity surgery, which have led to significant improvements in gross motor function and ambulation, especially in spastic quadriplegia, athetosis, and dystonia. The results of OS can be dramatic and life altering for the person with CP and their caregivers if it is performed meticulously by a specialized surgical team, at the appropriate age, for the correct indications, employing sound biomechanical principles and is followed by physician-led, protocol based, intensive, multidisciplinary, institutional rehabilitation, and long term followup. However, OS can be a double-edged sword, and if performed less than optimally, and without the supporting multidisciplinary medical and rehabilitation team, expertise and infrastructure, it often leads to significant functional worsening of the person with CP, including irretrievable loss of previous ambulatory capacity. OS must be integrated into the long term management of the person with CP and should be anticipated and planned at the optimal time and not viewed as a "last resort" intervention or failure of rehabilitation. This instructional course lecture reviews the relevant contemporary principles and techniques of OS in CP.

A Systematic Review of the Effects of Single-Event Multilevel Surgery on Gait Parameters in Children with Spastic Cerebral Palsy

BACKGROUND

Three-dimensional gait analysis (3DGA) is commonly used to assess the effect of orthopedic single-event multilevel surgery (SEMLS) in children with spastic cerebral palsy (CP).

PURPOSE

The purpose of this systematic review is to provide an overview of different orthopedic SEMLS interventions and their effects on 3DGA parameters in children with spastic CP.

METHODS

A comprehensive literature search within six databases revealed 648 records, from which 89 articles were selected for the full-text review and 24 articles (50 studies) included for systematic review. The Oxford Centre for Evidence-Based Medicine Scale and the Methodological Index for Non-Randomized Studies (MINORS) were used to appraise and determine the quality of the studies.

RESULTS

Except for one level II study, all studies were graded as level III according to the Oxford Centre for Evidence-Based Medicine Scale. The MINORS score for comparative studies (n = 6) was on average 15.7/24, while non-comparative studies (n = 18) scored on average 9.8/16. Nineteen kinematic and temporal-distance gait parameters were selected, and a majority of studies reported improvements after SEMLS interventions. The largest improvements were seen in knee range of motion, knee flexion at initial contact and minimal knee flexion in stance phase, ankle dorsiflexion at initial contact, maximum dorsiflexion in stance and in swing phase, hip rotation and foot progression angles. However, changes in 3DGA parameters varied based on the focus of the SEMLS intervention.

DISCUSSION

The current article provides a novel overview of a variety of SEMLS interventions within different SEMLS focus areas and the post-operative changes in 3DGA parameters. This overview will assist clinicians and researchers as a potential theoretical framework to further improve SEMLS techniques within different SEMLS focus groups. In addition, it can also be used as a tool to enhance communication with parents, although the results of the studies can't be generalised and a holistic approach is needed when considering SEMLS in a child with spastic CP.

Body mass index in ambulatory children with cerebral palsy: A cohort study

AIM

Children with cerebral palsy (CP) have reduced levels of physical activity compared with children without physical disability and experience risk factors for becoming overweight or obese. In the Australian CP population, there is little information available about the weight status of children with CP. The aims of this study were to compare the distribution of body mass index (BMI) in a cohort of ambulant children with CP with the BMI distribution of Australian children and explore the relationship between BMI and gross motor function.

METHODS

A retrospective cohort study of 587 children with CP Gross Motor Function Classification System (GMFCS) levels I-III who attended a Gait Laboratory between July 1995 and January 2012 was carried out. The BMI and Z-score were calculated at each assessment. Data were grouped into the categories of underweight, healthy, overweight and obese according to age-specific and sex-specific percentiles.

RESULTS

There were 348 boys and 240 girls with a mean age 11.2 (standard deviation 3.2) years. Mean BMI Z-score was 0.11 (standard deviation 1.33). Seven percent of children were underweight, 73.6% healthy, 7.3% overweight and 12.1% obese. This was similar to the distribution of children without disability. The largest percentage of children in the healthy group were classified GMFCS I. The largest percentage of children in the obese group were classified GMFCS III.

CONCLUSIONS

In this cohort, 19.4% of ambulant children with CP were overweight or obese. This is of concern as BMI may impact on the outcomes of surgical intervention and rehabilitation. Further research is needed to determine the consequences of obesity for children with CP.

Predictors of outcome after single-event multilevel surgery in children with cerebral palsy

Aims

Single event multilevel surgery (SEMLS) has been shown to improve gait in children with cerebral palsy (CP). However, there is limited evidence regarding long-term outcomes and factors influencing them.

Methods

In total 39 children (17 females and 22 males; mean age at SEMLS ten years four months, standard deviation 37 months) with bilateral CP (20 Gross Motor Function Classification System (GMFCS) level II and 19 GMFCS level III) treated with SEMLS were included. Children were evaluated using gait analysis and the Gait Deviation Index (GDI) before SEMLS and one, two to three, five and at least ten years after SEMLS. A linear mixed model was used to estimate the effect of age at the surgery, GMFCS and follow-up period on GDI.

Results

There was a mean improvement of 12.1 (-15.3 to 45.1) GDI points one year after SEMLS (p <  0.001) and 10.3 (-23.1 to 44.2) GDI points ten years after SEMLS compared with before SEMLS (p < 0.001). GMFCS level III children aged ten to 12 years had the most improvement. The GMFCS III group had more surgical procedures at the index SEMLS (p < 0.001) and during the follow-up period (p = 0.039). After correcting for other factors, age at surgery was the only factor predictive of long-term results. Our model was able to explain 45% of the variance of the change in GDI at the different time points. Take home message: Children with GMFCS III level aged ten to 12 are the benchmark responders to SEMLS in the long-term. Cite this article: Bone Joint J 2016;98-B:278–81.

Long-term outcomes after multilevel surgery including rectus femoris, hamstring and gastrocnemius procedures in children with cerebral palsy

BACKGROUND/AIMS

Multilevel surgical intervention is a common approach for the correction of gait abnormalities in children with cerebral palsy (CP). The short-term outcomes for the combination of rectus femoris transfer, hamstring lengthening and gastrocnemius lengthening have been well documented using three-dimensional motion analysis. However, the impact of time, growth, and puberty on these short-term outcomes of this combination of procedures is not well understood. The purpose of this study was to evaluate the long-term outcomes of these procedures on gait in patients with CP.

METHODS

Twenty-two patients underwent rectus femoris transfers, medial hamstring lengthenings and gastrocnemius lengthenings in combination with a selection of other soft tissue and/or bony procedures of the lower limb. All patients had a pre-operative motion analysis and post-operative analysis one and 11 years following surgery.

RESULTS

Significant changes in both clinical and gait variables from pre to 1 year post surgery confirmed the short-term gait benefits of this combination of surgical procedures. Long-term follow-up data indicated that the passive range of motion gains noted 1 year after surgery were lost at the knee and ankle. However, the improvements in ankle dorsiflexion and knee extension at initial contact were maintained over 11 years. As well, peak ankle dorsiflexion in stance was maintained and peak ankle plantar flexor moments and powers did not show declines long-term. Peak knee flexion showed a decline over the long-term, however, the timing of peak knee flexion in swing was maintained.

CONCLUSION

When compared to declines in gait kinematics in persons with CP without surgery, these results demonstrate the possible long-term benefits of surgical intervention.

Gait improvement surgery in ambulatory children with diplegic cerebral palsy

BACKGROUND AND PURPOSE

Instrumented 3-D gait analyses (GA) in children with cerebral palsy (CP) have shown improved gait function 1 year postoperatively. Using GA, we assessed the outcome after 5 years and evaluated parental satisfaction with the surgery and the need for additional surgery.

PATIENTS AND METHODS

34 ambulatory children with spastic diplegia had preoperative GA. Based on this GA, the children underwent 195 orthopedic procedures on their lower limbs at a mean age of 11.6 (6-19) years. On average, 5.7 (1-11) procedures per child were performed. Outcome measures were evaluation of gait quality using the gait profile score (GPS) and selected kinematic parameters, functional level using the functional mobility scale (FMS), and the degree of parental satisfaction.

RESULTS

The mean GPS improved from 20.7° (95% CI: 19-23) preoperatively to 15.4° (95% CI: 14-17) 5 years postoperatively. There was no significant change in GPS between 1 and 5 years. The individual kinematic parameters at the ankle, knee, and hip improved statistically significantly, as did gait function (FMS). The mean parental satisfaction, on a scale from 0 to 10, was 7.7 (2-10) points. There was a need for additional surgical procedures in 14 children; this was more frequent in those who had the index operation at an early age.

INTERPRETATION

The main finding was that orthopedic surgery based on preoperative GA gave marked improvements in gait function and quality, which were stable over a 5-year period. Nevertheless, additional orthopedic procedures were necessary in almost half of the children and further follow-up with GA for more than 1 year postoperatively is recommended in children with risk factors for such surgery.

The effects of progressive resistance training on daily physical activity in young people with cerebral palsy: a randomised controlled trial

PURPOSE

To examine if individualised resistance training increases the daily physical activity of adolescents and young adults with bilateral spastic cerebral palsy (CP).

METHOD

Young people with bilateral spastic CP were randomly assigned to intervention or to usual care. The intervention group completed an individualised lower limb progressive resistance training programme twice a week for 12 weeks in community gymnasiums. The primary outcome was daily physical activity (number of steps, and time sitting and lying). Secondary outcomes included muscle strength measured with a one-repetition maximum (1RM) leg press and reverse leg press. Outcomes were measured at baseline, 12 weeks and 24 weeks.

RESULTS

From the 36 participants with complete data at 12 weeks, there were no between-group differences for any measure of daily physical activity. There was a likely increase in leg press strength in favour of the intervention group (mean difference 11.8 kg; 95% CI -1.4 to 25.0). No significant adverse events occurred during training.

CONCLUSIONS

A short-term resistance training programme that may increase leg muscle strength was not effective in increasing daily physical activity. Other strategies are needed to address the low-daily physical activity levels of young people with bilateral spastic CP.

IMPLICATIONS FOR REHABILITATION

Progressive resistance training may increase muscle strength but does not lead to increases in daily physical activity of young people with bilateral spastic cerebral palsy (CP) and mild to moderate walking disabilities. Other strategies apart from or in addition to resistance training are needed to address the low daily physical activity levels of young people with bilateral spastic CP and mild to moderate walking disabilities.

A functional electrical stimulation system improves knee control in crouch gait

BACKGROUND

Crouch gait is a major sagittal plane deviation in children diagnosed with cerebral palsy (CP). It is defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase. To the best of our knowledge, functional electrical stimulation (FES) has not been used to decrease the severity of crouch gait in CP subjects and assist in achieving lower limb extension.

PURPOSE

To evaluate the short- and long-term effects of FES to the quadriceps muscles in preventing crouch gait and achieving ankle plantar flexion, knee and hip extension at the stance phase.

METHODS

An 18-year-old boy diagnosed with CP diplegia [Gross Motor Function Classification System (GMFCS) level II] was evaluated. The NESS L300(®) Plus neuroprosthesis system provided electrical stimulation of the quadriceps muscle. A three-dimensional gait analysis was performed using an eight-camera system measuring gait kinematics and spatiotemporal parameters while the subject walked shod only, with ground reaction ankle foot orthotics (GRAFOs) and using an FES device.

RESULTS

Walking with the FES device showed an increase in the patient's knee extension at midstance and increased knee maximal extension at the stance phase. In addition, the patient was able to ascend and descend stairs with a "step-through" pattern immediately after adjusting the FES device.

CONCLUSIONS

This report suggests that FES to the quadriceps muscles may affect knee extension at stance and decrease crouch gait, depending on the adequate passive range of motion of the hip, knee extension, and plantar flexion. Further studies are needed in order to validate these results.

Patellar tendon shortening for flexed knee gait in spastic diplegia

We evaluated the outcome of three different approaches to the management of flexed knee gait patients with spastic diplegia. The three surgical procedures were patellar tendon shortening (PTS), PTS combined with rotational osteotomies of the femur and/or tibia, and PTS combined with supracondylar extension osteotomy (SEO) of the distal femur. The primary outcome measure was gait kinematics. The knee gait variable score (GVS) and the gait profile score (GPS) were derived from gait kinematics. 24 patients (16 male and 8 female), mean age 16.1 years (SD 5.8 years), who had surgery between 2002 and 2008, were followed for a mean of 22 months. Knee extension during gait improved by a mean of 20° throughout the gait cycle, with an improvement in the knee GVS of 14° (p<0.001). The overall gait pattern improved with a mean decrease in GPS of 4.6°. Correction of patella alta was demonstrated by an improvement in the Koshino index from 1.34 pre-operatively to 1.10 post-operatively (p<0.001). Knee and gait kinematics, physical examination measures and Koshino Index improved in all three surgical groups, suggesting that a tailored approach to the correction of flexed knee gait in spastic diplegia is both feasible and appropriate.

LEVEL OF EVIDENCE

Level III.

Identification of common gait disruption patterns in children with cerebral palsy

Identification and classification of common gait deviation patterns in children with cerebral palsy facilitates communication between healthcare providers, provides insight into the natural history of functional ambulation, guides clinical decision making, and clarifies outcomes assessment. Previous classification schemes have been based on experiential and intuitive approaches or systematic and analytical approaches. The current gait disruption classification system has been refined to incorporate the most clinically useful aspects of previous systems. This paradigm uses the concept of primary versus compensatory deviations to identify common patterns and common causes for these patterns. The primary sagittal plane patterns include jump, crouch, and stiff gait. The primary transverse plane patterns include internal, external, and neutral progression gait. Apparent coronal plane deviation patterns are usually the consequence of sagittal and transverse plane deviations seen out of plane. Individualized assessment is essential because of the great variation in and combinations of possible patterns.

Comparison of hamstring transfer with hamstring lengthening in ambulatory children with cerebral palsy: further follow-up

BACKGROUND

Overactivity or contractures of the hamstring muscles in ambulatory children with cerebral palsy (CP) can lead to either a jump gait (knee flexion associated with ankle plantar flexion) or a crouch gait (knee flexion associated with ankle dorsiflexion). Hamstring lengthening is performed to decrease stance knee flexion. However, this procedure carries the potential risk of weakening hip extension power as well as recurrence over time; therefore, surgeons have adopted a modified procedure wherein the semitendinosus and gracilis are transferred above the knee joint, along with lengthening of the semimembranosus and biceps femoris.

PURPOSE

The purpose of our study is to evaluate the differences between hamstring lengthening alone (HSL group) and hamstring lengthening plus transfer (HST group) in the treatment of flexed knee gait in ambulatory children with CP. We hypothesized that recurrence of increased knee flexion in the stance phase will be less in the HST group at long-term follow-up, and hip extensor power will be better preserved.

METHODS

Fifty children with CP who underwent hamstring surgery for flexed knee gait were retrospectively reviewed. All subjects underwent a pre-operative gait study, a follow-up post-operative gait study, and a long-term gait study. The subjects were divided into two groups; HSL group (18 subjects) or HST group (32 subjects). The mean age at surgery was 9.9 ± 3.3 years. The mean follow-up time was 4.4 ± 0.9 (2.7-6.3) years.

RESULTS

On physical examination, both groups showed improvement in straight leg raise, knee extension, popliteal angle, and maximum knee extension in stance at the first post-op study, and maintained this improvement at the long-term follow-up, with the exception of straight leg raise, which slightly worsened in both groups at the final follow-up. Both groups improved maximum knee extension in stance at the initial follow-up, and maintained this at the long-term follow-up. Only the HST group showed significant (p < 0.05) improvement in the peak hip extension power in stance at the first post-op study, and this increased further at the final follow-up. In the HSL group, there was an initial slight decrease in the hip extension power, which subsequently increased to pre-operative values at the long-term study. Only the HST group showed increase of the average anterior pelvic tilt at the long-term follow-up study, although this was small in magnitude. There were two subjects who developed knee recurvatum at the post-op study, and both were in the HST group.

CONCLUSIONS

There is no clear benefit in regards to recurrence when comparing HST to HSL in the long term. In both HSL and HST, there was reduction of stance phase knee flexion in the long term, with no clear advantage in either group. Longer follow-up is needed for additional recurrence information. There was greater improvement of hip extension power in the HST group, which may justify the additional operative time of the transfer.

SIGNIFICANCE

This study helps pediatric orthopedic surgeons choose between two different techniques to treat flexed knee gait in patients with CP by showing the long-term outcome of both procedures.

Reported outcomes of lower limb orthopaedic surgery in children and adolescents with cerebral palsy: a mapping review

AIM

Lower limb surgery is often performed in ambulatory children with cerebral palsy (CP) to improve walking ability. This mapping review reports on outcome measures used in the published literature to assess surgical results, determine range and frequency of use, and map each measure to the International Classification of Functioning, Disability and Health.

METHOD

A mapped review of literature published between 1990 and 2011 was carried out to identify papers reporting the outcomes of lower limb orthopaedic surgery in ambulatory children with CP, aged 0 to 20 years.

RESULTS

A total of 229 published papers met the inclusion criteria. Thirty-two outcome measures with known psychometric properties were reported in the 229 papers. Twenty measures assess impairments in body structure and function and were used in 91% of studies. Ten measures assess restrictions in activity and participation and were used in 9% of papers. Two measures assessed quality of life. Since 1997, 29% of papers have used the Gross Motor Function Classification System to describe participants.

INTERPRETATION

The body of literature evaluating outcomes of lower limb orthopaedic surgery in CP is small but increasing. There is a need to develop a suite of outcome measures that better reflect outcomes across the International Classification of Functioning, Disability and Health, including activity and participation.

Assessment and treatment of children with cerebral palsy

Children with cerebral palsy are prone to development of musculoskeletal deformities. The underlying neurlogic insult may results in a loss of selective motor control, an increase in underlying muscle tone, and muscle imbalance, which can lead to abnormal deforming forces acting on the immature skeleton. The severely involved child is one who is at increased risk for developing progressive musculoskeletal deformities. Close surveillance and evaluation are key to addressing the underlying deformity and improving and maintaining overall function.

Quantification of patellar tendon shortening in a patient with cerebral palsy

PURPOSE

In the last few years the use of patellar tendon shortening procedure appears to give good results for the treatment of crouch gait in Cerebral Palsy (CP) patients. It offers a secondary approach in cases where conventional hamstrings lengthening failed. The evidence for the effectiveness of knee extensor shortening is poor and only one study quantitatively assessed the effects of this technique performed in addition to other procedures in CP patients. In this case study we used Gait Analysis (GA) to quantify the effects of patellar tendon shortening for the management of crouch gait persisting after hamstring lengthening.

METHODS

Crouch persisted seven years after a first multilevel procedure including hamstring lengthening in a 15-year old male. Gait was assessed over time (before and from six to 18 months after knee extensor shortening) with Gait Analysis (GA).

RESULTS

Before treatment the patient walked slowly and with a high duration stance phase; sagittal kinematics revealed excessive hip and knee flexion and ankle dorsiflexion during the whole gait cycle. After surgery, data showed progressive significant improvements at all lower limb levels during the follow-ups considered; gait became more physiologic and lower limb joint kinematics improved overall.

CONCLUSIONS

The results demonstrated that addressing the other side and shortening the antagonists may be a valuable option to treat crouch gait in patients with CP especially if this persists after hamstring and knee extension surgery.

The effects of surgical lengthening of hamstring muscles in children with cerebral palsy--the consequences of pre-operative muscle length measurement

Children with cerebral palsy often undergo multiple orthopaedic surgical procedures in a single episode. Evidence of the effectiveness of individual components within the overall package is sparse. The introduction of musculoskeletal modelling in Oswestry has led to a more conservative management approach being taken with hamstring muscles for children walking in a degree of crouch. Muscles which were shown to be of at least normal length at initial contact were not surgically lengthened, as would have been the case previously. A retrospective review of 30 such patients was therefore possible, comparing 15 patients treated before the policy change who had their hamstrings lengthened with 15 treated after who did not. All patients had pre and post operative gait assessments and significant changes were observed for each group separately and for the two groups when compared. The comparison revealed that preserving the hamstrings does tend to reduce, and therefore normalize, the dynamic muscle length. Examination of the two patient groups separately, however, reveals a more complex picture with more global gait improvements seen when the hamstrings were lengthened. No absolute recommendation can be made to inform the clinical management of all children with normal to long hamstring muscles during gait. The final decision of whether to include a hamstring lengthening will need to take into account the characteristics of the individual child.

Crouch gait changes after planovalgus foot deformity correction in ambulatory children with cerebral palsy

Ambulatory children with cerebral palsy (CP) may present with several gait patterns due to muscular spasticity, commonly with crouch gait. Several factors may contribute to continuous knee flexion during gait, including hamstring and gastrocnemius contracture. In planovalgus foot deformity, the combination of heel equinus, talonavicular joint dislocation, midfoot break and external tibial torsion also contribute to crouch gait as part of lever arm dysfunction. In this retrospective cohort study, we assessed 21 children with CP (34 feet) who underwent planovalgus foot correction as a single level surgery. Fifteen feet underwent subtalar fusion and 19 feet had lateral calcaneal lengthening. Patients who underwent knee, hip or pelvis surgeries were excluded from the study. The aim was to examine the changes in gait pattern and the correlation between the changes of knee flexion at stance phase with the other kinematic and kinetic parameters after foot surgery. Post surgery change of Maximum knee extension at stance (MKE-dif) was the outcome of interest. The magnitude of change in MKE after surgery increased (less crouch after surgery) in patients who had milder preoperative planovalgus feet and higher preoperative ankle maximum dorsiflexion at stance and ankle power. The gain of knee extension after surgery correlated with correction of ankle hyperdorsiflexion and with increase of knee extension at initial contact and knee power. Patients with high preoperative ankle maximum dorsiflexion may benefit from surgical foot deformity correction to achieve decreased ankle dorsiflexion with no knee surgical intervention.

[Spastic foot deformities in children: surgical management]

Although the neurological defects associated with cerebral palsy are not progressive, secondary musculoskeletal disorders due to growth and gravity are variable. In the clinical analysis of spastic foot deformities different mechanisms that produce a variety of deformities have to be analyzed. The goals of surgical treatment are correction of the deformity, reestablishment of stability of the foot and preservation of functionally important ranges of motion and muscle strength. The most common spastic foot deformities are equinus, planovalgus, equinovarus and calcaneus. For treatment soft tissue surgery, such as muscle lengthening and transfer together with bone surgery, such as osteotomy or arthrodesis are used and combinations of these methods are often required. Subsequently postoperative plasters are necessary followed by dynamic orthotic management.

Flexed-knee gait in children with cerebral palsy: a 10-year follow-up study

BACKGROUND

While several studies have evaluated the short-term effectiveness of conservative and surgical treatment of flexed-knee gait in children with cerebral palsy (CP), few have explored the long-term outcomes using gait analysis. The purpose of this study was to examine, through gait analysis, the 10-year outcomes of flexed-knee gait in children with CP.

METHODS

Ninety-seven children with spastic CP who walked with a flexed-knee gait underwent two gait evaluations [age 6.1 ± 2.1 and 16.2 ± 2.3 years, Gross Motor Function Classification System (GMFCS) I (12), II (45), III (37), IV (3)]. Limbs with knee flexion at initial contact >15° were considered walking with a flexed-knee gait and were included in the study (n = 185). Kinematic data were collected using an eight-camera motion analysis system (Motion Analysis, Santa Rosa, CA). Surgical and therapeutic interventions were not controlled.

RESULTS

A comparison between the two gait studies showed an overall improvement in gait at 10 years follow-up. Significant improvements were seen in knee flexion at initial contact, Gait Deviation Index (GDI), Gross Motor Function Measure (GMFM), and gait speed (P < 0.01 for all). Outcome was also evaluated based on the severity of flexed-knee gait at the initial visit, with functional skills and overall gait (GDI) improving in all groups (P < 0.01 for all). The group with a severe flexed-knee gait exhibited the most improvement, while subjects with a mild flexed-knee improved the least.

CONCLUSIONS

Children at a specialty hospital whose orthopedic care included gait analysis and multi-level surgery showed improvement of flexed-knee gait and gross motor function over a 10-year course, regardless of the initial severity.

Effects of simulated crouch gait on foot kinematics and kinetics in healthy children

Identification of secondary and tertiary impairments in neurologically induced gait deviations, such as crouch gait, is not always straightforward, but essential in order to decide upon the most efficient medical treatment in patients with cerebral palsy (CP). Until now, exact intersegmental dependency of the development of foot deformities has not been investigated. Therefore, the aim of this study was to explore if an artificially induced bilateral knee flexion contracture causes compensatory mechanisms in foot motion during gait in healthy children. Three-dimensional kinematic and kinetic data from 30 healthy children (mean age 10.6 years) were derived from the Oxford Foot model (OFM). Participants walked first in an artificially induced crouch gait (limitation of knee extension to 40°) and then normally. Walking speed was kept the same in both conditions. Analysis revealed small but significant (p<0.05) differences between the two conditions in hindfoot and forefoot kinematics in all three planes during the stance phase as well as for all peak internal moments within the foot. In general the foot tended to compensate for an artificial knee flexion contracture with an increase in maximal dorsiflexion, eversion and external rotation of the hindfoot, which also allowed increased foot motion in other foot segments. The results of this study showed that an isolated proximal joint contracture had an influence on foot position during stance in healthy children. Further interpretation of the data in relation to CP children will be possible as soon as comparable OFM data of pathological crouch gait is available.