[Correction of complex defomities around the Knee Joint]. / Komplexe Achskorrekturen um das Kniegelenk.

Complex deformities around the knee joint are usually severe and have several aetiologies. They can be present in one or more planes, with variations in severity between planes. The occurrence and progression of the deformity can be influenced by local and systemic factors. Several types of osteotomies and fixation methods are available to correct these complex deformities. The selection of the osteotomy used to correct a deformity depends on the type of deformity, its severity and its aetiology. Therefore, precise planning taking into consideration the above factors is necessary to achieve the goal.

Is there a correlation between static radiographs and dynamic foot function in pediatric foot deformities?

BACKGROUND: Idiopathic flexible flatfeet, congenital clubfeet and pes cavovarus are the most common foot deformities in children. Accurate assessment to quantify the severity of these deformities by clinical examination alone can be challenging. Radiographs are a valuable adjunct for accurate diagnosis and effective treatment. However, static radiographs during relaxed standing may not reflect the dynamic changes in the foot skeleton during functional activities such as walking. Therefore, the aim of this study is to predict dynamic foot movements during walking from planar standing radiographs to reveal the significance of the radiographic analysis for the assessment of foot function. METHODS: Patients 8-17 years with flexible flatfeet (FFF, n=217) recurrent clubfeet (RCF n=38) and overcorrected clubfeet (OCCF, n=71) of non-neurogenic or syndromic origin and pes cavovarus due to peripheral neuropathy (PNP, n=48) were retrospectively included. Patients underwent gait analysis with the Oxford Foot Model and radiographic examination in anterior-posterior and lateral view during standing. Multilinear predictor analysis of selected gait parameters was performed based on radiographic measures. RESULTS: The variance that was explained by radiography was greatest for the transverse plane forefoot abduction with 33% for OCCF, 50% for RCF and 59% for PNP. Flatfeet and foot kinematics in the other planes or between rearfoot and tibia showed little or no relation. CONCLUSIONS: The static measures of foot deformities by radiography could explain only a small amount of variance in foot kinematics during walking, in particular for FFF. An explanation may be that the forces during weight bearing bear little resemblance to those during gait in terms of neither magnitude nor direction. These findings suggest that foot function cannot be accurately assessed solely from static radiographic observations of the foot, commonly undertaken in clinical practice.

Long-term results of multilevel surgery in adults with cerebral palsy.

BACKGROUND: Deterioration of gait in adolescent and adult patients with cerebral palsy can be associated with multiple factors. Multilevel surgery (MLS) is one option in adults with cerebral palsy to improve gait function with encouraging short-term results. It is a question whether these improvements are maintained over time. METHODS: In a retrospective consecutive cohort study, adults with bilateral spastic cerebral palsy (BSCP) treated with MLS between 1995 and 2011 were scanned for potential inclusion. Patients needed to fulfill the following inclusion criteria: age at MLS > 17, standardized three-dimensional gait analysis (3D-GA) including clinical examination at pre-operative (E0), a short-term follow-up (E1) and at least seven years (E2) after the index MLS. Twenty adults (10 women, 10 men) with a Gross Motor Function Classification Level (GMFCS) I-III and a mean age at MLS of 24.8 years were included in this study. The average long-term follow-up was 10.9 years. The Gait Profile Score (GPS) was used as primary outcome measure. RESULTS: The GPS improved significantly from 13.8° before surgery to 11.2° at short-term (p = 0.007) and to 11.3° at long-term follow-up (p = 0.002). Mean GPS showed a slight deterioration between E1 and E2 due to a minority of six patients (30%) who showed a significant loss of correction. CONCLUSION: Surgical treatment in adults with BSCP was feasible and effective in the long-term. Significant improvement of gait and function was maintained in the majority of patients, while some patients were prone to develop crouch gait, hip flexion contractures, or pain.

Long-term development of gait after multilevel surgery in children with cerebral palsy: a multicentre cohort study.

AIM: We investigated the long-term efficacy and safety of multilevel surgery (MLS) in ambulatory children with bilateral spastic cerebral palsy (CP). METHOD: Two hundred and thirty-one children were evaluated at short term (1.1y, SD 0.4) and long term (9.1y, SD 3.0) follow-up using clinical examination and gait analysis. MLS was investigated by studying changes in the Gait Profile Score (GPS) referenced to the minimally important clinical difference. RESULTS: Ambulatory children aged 10 years and 7 months (SD 2y 11mo) at MLS in Gross Motor Function Classification System levels I (19), II (144), and III (68) showed a decrease (improvement) in preoperative GPS from 16.3° (SD 4.8) to 11.3° (SD 3.2) at short-term follow-up, an improvement of 5°. At long-term follow-up, GPS was maintained at 11.4° (SD 3.1). Overall, 177 (76.6%) children maintained their improvement in GPS after 9 years. INTERPRETATION: Multilevel surgery is a safe and effective surgical intervention, which leads to a significant improvement in gait kinematics in children with bilateral spastic CP. This study improves our understanding of MLS in the long term and will help to inform families and children when planning for MLS. WHAT THIS PAPER ADDS: Largest study of multilevel surgery (MLS) for children with bilateral spastic cerebral palsy, with longest follow-up. MLS resulted in significant long-term improvements in gait function. Minor adverse events were common, while events requiring intervention were uncommon (4% of children). Thirty-nine per cent of children required additional surgery during follow-up. 'Single-event multilevel surgery' was changed to the more realistic term 'multilevel surgery'.

Reliability and accuracy in three-dimensional gait analysis: a comparison of two lower body protocols.

The standard Plug-in-Gait (PiG) protocol used in three-dimensional gait analysis is prone to errors arising from inconsistent anatomical landmark identification and knee axis malalignment. The purpose of this study was to estimate the reliability and accuracy of a custom made lower body protocol (MA) compared with the PiG protocol. Twenty-five subjects volunteered to evaluate the intertrial reliability. In addition, intersession reliability was examined in 10 participants. An indirect indicator of accuracy according to the knee varus/valgus and flexion/extension range of motion (ROM) was used. Regarding frontal plane knee angles and moments as well as transverse plane motions in the knee and hip joint, the intersession errors were lower for the MA compared with the standard approach. In reference to the knee joint angle cross-talk, the MA produced 4.7° more knee flexion/extension ROM and resulted in 6.5° less knee varus/valgus ROM in the frontal plane. Therefore, the MA tested in this study produced a more accurate and reliable knee joint axis compared with the PiG protocol. These results are especially important for measuring frontal and transverse plane gait parameters.

Treatment of spastic varus/ equinovarus foot with split-tendon transfers in cerebral palsy: How does it affect the hindfoot motion?

INTRODUCTION: The flexible spastic varus foot in cerebral palsy is commonly corrected by split-tendon transfer of tibialis anterior or tibialis posterior. These tendon transfers are said to preserve hindfoot motion, which is until now not been proven. Therefore, the aim of the study was to show the hindfoot motion following split-tendon transfer in comparison to a midtarsal arthrodesis. MATERIALS AND METHODS: A retrospective study was done on patients with flexible spastic varus foot in cerebral palsy who underwent a combined split-tendon transfer of tibialis anterior and posterior. Patients with a rigid foot deformity underwent a midfoot arthrodesis. These children and normal children served as controls. An instrumented gait analysis was done in all patients before and at follow-up. A statistical analysis was done using 2-factor ANOVA with repeated measures on time. RESULTS: Thirteen children underwent a combined split-tendon transfers of tibialis anterior and posterior muscles and 14 children midtarsal arthrodesis. The mean follow-up was 2.4 (SD=0.8) years for flexible varus foot and 1.9 (SD=0.7) years for rigid foot deformity. The preoperative hindfoot range of motion in eversion-inversion was 54% and 49% of TD controls in flexible varus foot and rigid foot deformity respectively. At follow-up, it reduced further to 45% and 42% of TD controls in the respective groups. CONCLUSION: Both flexible and rigid hindfoot deformity reduced the hindfoot motion. However following surgery, the hindfoot motion reduced further and was identical in both groups independent of the type of surgery. This indicates a tenodesis-effect of split-tendon transfers on the hindfoot.

Pain in Adults With Cerebral Palsy After Single-Event Multilevel Surgery.

OBJECTIVE: The aim of the investigation was to assess the contribution of pain to functional, social, and health-related quality-of-life outcomes in adults with cerebral palsy. DESIGN: This monocentric, prospective study included long-term data for ambulant adults with cerebral palsy and at levels I-III in the Gross Motor Function Classification System who had received orthopedic multilevel surgery in adulthood and in whom preoperative and postoperative three-dimensional gait analysis was conducted, including the Gait Profile Score. A questionnaire including the Visual Analog Scale, Oswestry Disability Index, and European Quality of Life 5 Dimensions 3 Level was analyzed. RESULTS: Twenty-four adults at a mean age of 38.0 yrs were included. Sixteen patients (66.7%) indicated that they experienced pain and 10 patients (41.7%) had pain for more than 6 mos. Overall, 13 patients (54%) experienced both pain and anxiety. There was no correlation of the Gait Profile Score with pain, Gross Motor Function Classification System, and Oswestry Disability Index. The Oswestry Disability Index showed a positive correlation with the Gross Motor Function Classification System (r = 0.39, P = 0.05) and pain (r = 0.57, P = 0.004). CONCLUSIONS: Pain and anxiety represent relevant comorbidities in adults with cerebral palsy. The occurrence of pain correlates with the Oswestry Disability Index and is higher than in children with cerebral palsy.

Is shortening of Tibialis Anterior in addition to calf muscle lengthening required to improve the active dorsal extension of the ankle joint in patients with Cerebral Palsy?

INTRODUCTION: Shortening of the tibialis anterior tendon (TATS) has been shown to improve the ankle dorsiflexion in swing following the calf muscle lengthening procedure (CMLP) in patients with cerebral palsy (CP). Others have reported the similar improvements following CMLP but without TATS. However there are no studies comparing both procedures. Therefore the purpose of the study was to compare the ankle dorsiflexion in swing and foot position in the sagittal plane during gait following TATS and CMLP to that of CMLP alone. MATERIALS AND METHODS: A retrospective study was carried out in CP patients who presented with fixed equinus deformity. They were grouped into unilateral CP and bilateral CP. Depending on the procedures, each group was again subdivided into subgroup CMLP only and subgroup CMLP and TATS (CMLPTATS). All patients were subjected to pre and postoperative clinical and gait analysis. RESULTS: 44 feet in 44 patients were included in the study. Of these, 24 feet (24 patients) belonged to unilateral and 20 feet (20 patients) to bilateral CP group. The mean age of the patients at surgery was 11.5 years (6.0 - 29.0) in the unilateral CP group and 10.5 years (5.0-34.0) in the bilateral CP group. In the unilateral CP group, 12 feet belonged to subgroup CMLP and 12 to subgroup CMLPTATS with a mean equinus contracture of 7.5° in both subgroups. In bilateral CP group, 11 feet belonged to subgroup CMLP with a mean equinus contracture of 5° and 9 to subgroup CMLPTATS, with a mean equinus contracture of 10°. The subgroups did not vary significantly in the demographics, anthropometry, kinematics and kinetics of ankle joint preoperatively. The mean follow up time was 19.7 months. The surgery produced significant changes in both groups and subgroups. However, none of the relevant gait parameters were significantly different between groups and subgroups. SIGNIFICANCE: Adding TATS to CMLP, compared to CMLP alone did not improve ankle dorsiflexion in swing and the foot position more than CMLP alone.

The Ability to Run in Young People with Cerebral Palsy before and after Single Event Multi-Level Surgery.

The objective of the study is to identify and evaluate possible factors that influence the ability to run before and after single event multi-level surgery (SEMLS). Young patients (6-25 years) with spastic cerebral palsy (GMFCSI-II) were retrospectively included. Type and number of surgical procedures, time for recovery and 3D gait analysis variables were analyzed with respect to the ability to run. In total, 98 patients (38 females; 60 males) who received SEMLS (12 years, SD 3.4) were included and compared to a control group of 71 conservatively treated patients. Of 60 runners pre-surgery, 17 (28%) lost the ability, while gained in 8 of 38 (21%) non-runners. The number of surgical procedures was a significant predictor and those who lost their ability to run had significantly more (mean = 5.9, SD = 1.7), compared to the patients who gained the ability (mean = 3.5, SD = 0.9). Further, pre-surgical function (e.g., gait speed) was significantly different (p < 0.001). Pre-surgical function and the number of surgical procedures seem to play an important role for the gain or loss of the ability to run after surgery. Caution is warranted in patients with lower pre-surgical function and the ability to run, as they seem at a higher risk to lose the ability.

Does an overcorrected clubfoot caused by surgery or by the Ponseti method behave differently?

BACKGROUND: Overcorrection is a recognized problem following surgical treatment of congenital clubfoot. Recently this complication has also been mentioned following Ponseti treatment. RESEARCH QUESTION: Do overcorrected clubfeet (OCCF) caused by surgery behave differently from those caused by Ponseti treatment in terms of segmental motion of the feet and show differences in the severity of deformity on X-rays? METHODS: Children between 7 and 12 years with OCCF were included in this study. Depending on the aetiology causing them, the feet were divided into 2 groups (Ponseti and peritalar release surgery). 25 typically developing children served as controls. All subjects were subjected to clinical and radiological examination and 3-Dimensional gait analysis using the Oxford Foot Model. RESULTS: Thirty-two children with OCCF, of these 18 feet in the surgical and 14 feet in the Ponseti group, were included in the study. No radiological differences were seen in the flatfoot parameters between OCCF groups except in the calcaneal inclination angle that was more pathological in the Ponseti group. The clinical ankle plantar flexion was significantly reduced in the surgical group. During walking the range motion of the hindfoot in the frontal plane was significantly reduced in surgically treated feet compared to the Ponseti group. The other parameters did not show any significant difference between groups. SIGNIFICANCE: The overcorrected clubfeet following surgery and Ponseti showed similar appearance and showed no significant differences in 11/12 radiological parameters. The segmental motion of the feet showed no significant differences between groups except the in the range of motion of the subtalar eversion. A considerable subtalar joint motion was present even in the surgical group. These findings might help plan the treatment of these feet.

Self-perceived foot function and pain in children and adolescents with flexible flatfeet - Relationship between dynamic pedobarography and the foot function index.

BACKGROUND: There is considerable debate as to which parameters to include in the assessment of paediatric flatfeet. Dynamic pedobarography is an objective, dynamic method to measure foot function. Information about its associations to patient-reported measures may help to focus on the most relevant parameters. RESEARCH QUESTION: What is the association between the Foot Function Index and pedobarographic assessments in flatfeet of children and adolescents? METHODS: A consecutive clinical case series of 51 participants with idiopathic flexible flatfeet aged 7-17 years underwent barefooted pedobarography during gait and completed the Foot Function Index Questionnaire. Pedobarographic data categorized into values related to area, peak pressure and force with respect to the hind-, mid- and forefoot were extracted. To test the associations between the Foot Function Index and pedobarographic assessments, bivariate partial correlations were tested and contact times served as co-variate. RESULTS: Several significant associations between peak pressure or forces beneath the hindfoot, midfoot and hallux to self-perceived function were found (|rho| = 0.28-.46, P < 0.05). In particular, reduced peak forces and pressures underneath the hindfoot and hallux, a lateral shift (smaller medio-lateral ratios) of hindfoot pressure and force and a medial shift (larger medio-lateral ratios) of midfoot pressure seem to be negatively associated with foot-related disability. Overall, less evidence was noted for associations to pain scores. Area related outcomes (including the arch index) contained no information for function while a larger BMI was the strongest thread for disability (rho = 0.42, P = 0.002) and pain (rho = 0.31, P = 0.027). SIGNIFICANCE: When using pedobarography for the assessment of flexible flatfeet of children and adolescents, less attention should be paid to area related measurements which do not provide information about self-perceived function or disability. Instead, peak pressures or forces in the hind- or midfoot or beneath the hallux may be focussed. Weight reductions are potentially an effective strategy to reduce or prevent symptoms.

Kinematic adaptation and changes in gait classification in running compared to walking in children with unilateral spastic cerebral palsy.

BACKGROUND: Classification of sagittal gait patterns in unilateral spastic cerebral palsy (CP) provides direct implication for treatment. Five types are described: type 0 has minor gait deviation; type 1 has inadequate ankle dorsiflexion in swing; type 2 has inadequate ankle dorsiflexion throughout the gait cycle; types 3 and 4 have abnormal function of the knee and hip joint respectively. During gait analysis of children with unilateral spastic CP we observed frequently that a knee flexion deficit disappeared during running. That may have an impact on classification and treatment. RESEARCH QUESTION: Does the classification type change while running and how do patients' kinematics adapt to running? METHODS: 64 children with unilateral spastic CP were classified using instrumented gait analysis for walking and running. The deviation of four parameters from typically developing children (TD) were used to distinguish between types: peak ankle dorsiflexion in swing for type 1, peak ankle dorsiflexion in stance for type 2, knee range of motion for type 3, and hip range of motion for type 4. A three-factor ANOVA for factors group (CP/TD), locomotion (walk/run) and limb side (in-/uninvolved) was conducted. RESULTS: The number of patients with type 1, 3 and 4 decreased considerably from walking to running, whereas, the number of type 0 and 2 patients increased. The ANOVA showed that three of four parameters of patients' pathologic limb adapt similarly to TD to running, except for the ankle dorsiflexion in stance. SIGNIFICANCE: Running shows that there is a natural way to resolve abnormalities. Therefore, recommended treatments of hip and knee joint abnormalities based on the walking classification can be questioned and additional running analysis may be important for surgical decision making.

Cluster analysis to identify foot motion patterns in children with flexible flatfeet using gait analysis-A statistical approach to detect decompensated pathology?

INTRODUCTION: The paediatric flexible flatfoot constitutes the major cause of clinic visits for orthopaedic foot problems. It shows variations of deformities in different planes and locations of the foot and its indication for treatment have been extensively discussed. Despite its high prevalence there exists no classification of flatfeet during walking as a prerequisite for treatment decision. Therefore, the aim of this study is to classify flexible flatfeet based on 3D foot kinematics during walking. METHODS: Patients age 7-17 years with flexible flatfeet (N = 129, 255 feet) of non-neurogenic or syndromic origin, were retrospectively included. Patients underwent gait analysis using the Oxford Foot Model after standard clinical examination. A k-means cluster analysis was performed on 3 scores derived from the principal component analysis of the foot kinematic waveforms over the gait cycle. Gait and clinical parameters were then statistically tested between clusters. RESULTS: Cluster analysis revealed two groups of flexible flatfeet that were discriminated best by the inversion at push-off during walking. Cluster 2, including 110 feet, showed an average eversion instead of an inversion at push-off and a lower number of heel rises in the clinical test. Both was significantly different between clusters (p < 0.001). DISCUSSION: Based on the findings, the resultant clusters can be interpreted as describing compensated and decompensated feet, with the latter presenting a group that may require surgical interventions, even if they are not yet present with pain. The hindfoot inversion capability at push-off is the most important variable in the 3D gait analysis to classify flexible flat feet.

Dynamic assist by carbon fiber spring AFOs for patients with myelomeningocele.

Patients with calf muscle insufficiency and a calcaneus gait are often dependent on ankle-foot orthoses (AFO). The orthosis is intended to improve walking and posture and should prevent structural deformities. AFOs are often manufactured with a dorsiflexion stop. The design of this type of orthosis has been investigated in several previous studies. In the current study, orthoses with a dorsal carbon fiber spring were compared with the classic design. Five patients with Spina Bifida took part in the current study. All participants underwent a 3D gait analysis including kinematic (VICON infrared cameras) and kinetic (Kistler force plates) data collection. The measurements showed that the carbon spring was able to support the patient during the complete stance phase. It was found that the use of a carbon fiber spring significantly increases the energy return during the 3rd rocker, simulating the natural push-off action (p<0.05). Via a simple mechanical test, the contribution of the carbon spring to the overall kinetics could be estimated proving that the spring does assist the patient for push-off. The more physiological ankle and knee kinematics implies a functional improvement from the carbon springs compared to classic orthosis. This investigation showed, further, that in the fitting process a neutral alignment with the shoe wear has to be carefully checked since the spring kinematics and kinetics during stance phase were influenced significantly by the alignment. Further studies are needed to assess the clinical outcome and to prove the functional benefit of this kind of orthosis.

Foot motion in children shoes: a comparison of barefoot walking with shod walking in conventional and flexible shoes.

The increased prevalence for flatfoot and hallux valgus in modern societies may be the consequence of inadequate footwear in childhood. Based on the assumption that barefoot walking represents the best condition for the development of a healthy foot the objective of this study was to monitor the influence of commercial footwear on children's foot motion during walking. Furthermore, an attempt was made to reduce this influence by changing the physical properties of standard footwear. Children's barefoot motion pattern was monitored by a marker-based optical 3D-tracking method using a multi-segment foot model. In the study's first stage, barefoot walking was compared to walking with a commercial product. In the second stage it was compared to both, the pattern with the commercial product and with the shoe modified on the basis of the findings of the first stage of the study. Eighteen children (8.2+/-0.7 years old) with no foot deformity and with the same shoe size were recruited for this study. It was found that tibio-talar ROM increased in the commercial shoe (26.6 degrees ) compared to the barefoot condition (22.5 degrees , p=0.001) whereas the medial arch changes for push-off were diminished since the variation in arch length was reduced from 9.9% (barefoot) to 5.9% (shoe, p<0.001). Further, ROM in foot torsion along the long foot axis was reduced from 9.8 degrees (bare) to 4.7 degrees (shoe, p<0.001). These parameters could be improved with more flexible footwear. The present study shows that slimmer and more flexible children's shoes do not change foot motion as much as conventional shoes and therefore should be recommended not only for children in this age but for healthy children in general.

Prevalence and predictors for the ability to run in children and adolescents with cerebral palsy.

BACKGROUND: Running is a fundamental movement skill and a prerequisite for children to participate in numerous daily activities. The prevalence of the ability to run in people with Cerebral Palsy and the role of their impairments on running ability are unknown. Therefore, the aim of this study is to determine the prevalence of the ability to run and to identify contributing factors. METHODS: In this study, 280 children and adolescents with spastic Cerebral Palsy, Gross Motor Function Classification System level II were included. The ability to run was defined by instrumented running analysis. Runners and non-runners were compared regarding their clinical measures of spasticity, weakness, and postural control. Logistic regression was applied to identify the most important predictors for the ability to run. FINDINGS: The ability to run was significantly higher in unilateral (67%) than in bilateral (55%) affected patients. Significant differences between runners and non-runners were found for spasticity, BMI and postural control, but not for muscle strength. Lower M. rectus femoris spasticity, higher m gastrocnemius spasticity and enhanced postural control appear to be the best predictors for being able to run. INTERPRETATION: Patients with Gross Motor Function Classification System level II represent a large group in the gait laboratory and the functional impairment within this group differs greatly. Therefore, for clinical decision making we suggest to separate patients in this group based on their running ability. Spasticity and postural control affect the ability to run and needs to be accounted for in intervention programs.

Effect of floor reaction ankle-foot orthosis on crouch gait in patients with cerebral palsy: What can be expected?

BACKGROUND: Floor reaction ankle-foot orthoses are commonly prescribed to improve knee extension of children with cerebral palsy having crouch gait. Their effectiveness is debated. Therefore, the objective of this study is to optimize current prescription criteria for the improvement of crouch gait. STUDY DESIGN: Cross-sectional interventional study. METHODS: A total of 22 patients with bilateral spastic cerebral palsy, between 6 and 17 years, Gross Motor Function Classification System II-IV participated in this study. Instrumented gait analysis was done under three conditions: barefoot, shoed, and with orthotics. Patients were divided into two groups: good and non-responders with more and less than 8.8° improvement of knee extension during walking, respectively. A multiple predictor analysis was done on parameters that were different between groups. RESULTS: In total, 12 of 22 patients showed good response in knee extension with a mean change of 17° (standard deviation = 5°). Good responders showed a significantly smaller walking velocity, knee extension strength, ankle plantarflexion strength, and greater external foot progression angle compared to non-responders. Foot progression angle together with ankle plantarflexion strength explained 37% of the variance in improvement of knee extension. CONCLUSION: With appropriate patient selection, an improvement of crouch gait by ankle-foot orthoses of 17° (standard deviation = 5°) can be expected. Patients with slow velocity, weak plantarflexors, and external foot progression benefit most. Joint contractures were no contraindications. Clinical relevance This study showed that gait in patients with low functional level benefit most from ankle-foot orthoses. Unlike in patients with higher functional status, contractures of hip, knee, and ankle did not reduce the positive effects on gait. The suggested prescription criteria may help to better select appropriate patients for orthotics.

Relationship between radiographic patella-alta pathology and walking dysfunction in children with bilateral spastic Cerebral Palsy.

BACKGROUND: Patella-alta is very common in patients with Cerebral Palsy (CP). While several diagnostic x-ray indices have been developed for patella-alta in general, the specific relationship with walking dysfunction in CP is only partly understood. METHODS: 33 participants with bilateral spastic CP between 4 and 20 years (GMFCS I-II without previous surgery) that underwent 3D gait analysis as well as a radiographic exam within 0.8 (SD 1.2) months were retrospectively included. The Caton-Deschamps, the Insall-Salvati and the Koshino-Index, as well as the moment-arms of the quadriceps, the pattelar-tendon length and patellar tilt angle were analyzed from x-rays. During gait, tempo-spatial parameters, the knee flexion kinematics, the knee moments and the moment impulse were calculated and correlated to x-ray parameters. RESULTS: Smaller quadriceps moment-arms were related to slower walking speed (r=0.48, P=0.005) and less knee extension during stance (r=0.68 P<0.001). Smaller quadriceps moment arms and longer patellar-tendons were also significantly related to a larger knee flexion moment impulse in the second half of the stance phase (r=-0.36, P=0.045 and r=0.39, P=0.028) and hence to more abnormal knee loads. Yet, none of the traditional indices was related to any parameter of gait. INTERPRETATION: Traditional radiographic indices for patella-alta possess little to no informative value for walking dysfunction in individuals with CP suspected to have knee pathology. Smaller moment-arms are a key feature of patellofemoral pathology in CP reducing the knee extensor mechanism, an aspect which is not sufficiently picked up by traditional indices.

Effects of backward-downhill treadmill training versus manual static plantarflexor stretching on muscle-joint pathology and function in children with spastic Cerebral Palsy.

BACKGROUND: Patients with spastic Cerebral Palsy are prone to equinus deformities, likely affected by short and inextensible plantarflexor muscles. Manual stretching is a popular treatment but its effectiveness concerning joint mobility, muscle-tendon morphometrics and walking function is debated. Eccentric exercise by backward-downhill treadmill training could be a therapeutic alternative for ambulatory patients improving gait and muscle function. RESEARCH QUESTION: What are the effects of eccentric training by backward-downhill treadmill training and plantarflexor stretching concerning gait and muscle function in patients with spastic Cerebral Palsy? METHODS: 10 independent ambulators with spastic Cerebral Palsy (12 [SD 4] years old, 2 uni- and 8 bilaterally affected) participated in a randomized crossover-study. One group started with manual static stretching, the other one with backward-downhill treadmill training. Each treatment period lasted 9 weeks (3 sessions per week). Pre and post treatments, 3D gait was assessed during comfortable and during fastest possible walking. Ultrasonography and dynamometry were used to test plantarflexor strength, passive joint flexibility, as well as gastrocnemius morphometrics, stiffness and strain on muscle-tendon and joint level. RESULTS: When comparing both treatments, backward-downhill treadmill training lead to larger single stance dorsiflexion at comfortable walking speed (+2.9°, P = 0.041) and faster maximally achievable walking velocities ( + 0.10 m/s, P = 0.017). Stretching reduced knee flexion in swing, particularly at faster walking velocities (-5.4°, P = 0.003). Strength, ankle joint flexibility, as well as stiffness on muscle-tendon and joint level were not altered, despite similar increases in passive muscle and fascicle strain with both treatments (P ≤ 0.023). SIGNIFICANCE: Backward-downhill treadmill training can be an effective gait treatment, probably improving coordination or reducing dynamic stretch sensitivity. More intense BDTT might be necessary to further alter muscle-tendon properties. Manual static plantarflexor stretching may not be optimal in Cerebral Palsy patients with high ambulatory status.