- Email: [email protected]
Predicting surgery effect on knee kinematics in cerebral palsy
S2
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
foot Study Group score, PODCI = Pediatric outcomes Data Collection Instrument and FRS = Functional Rating Score). Moreover, instrumented 3D gait analysis using the Oxford Foot Model was performed. The results were compared statistically by a nonparametric Mann–Whitney U test. Results: Both groups were comparable at the beginning of treatment with no significant difference in the Pirani score (p = 0.623). After 9.8 years of follow-up the Ponseti group presented superior in morphology (p = 0.024), functional (p = 0.006) as well as radiologic (p = 0.023) evaluation according to ICFSG. Also PODCI (p = 0.016) and FRS (p = 0.005) showed better functional status of children treated with the Ponseti method. Children treated with surgery had more troubles performing sports (p = 0.003) and experienced more pain (p = 0.006), which might also led to inferior results in happiness domain of PODCI (p = 0.03). Moreover, the gait analysis showed deficient hindfoot dorsiflexion (p = 0.039) in the surgical group. The forefoot kinematics did not show any differences between groups. Discussion: The most important finding comparing the longterm outcomes of Ponseti and surgical treatment is the increased stiffness and decreased range of motion at the ankle joint. The most probable reason for that is the scarring. Over time and with longer follow-up studies surgeons began to realize that scarring can lead to stiffness, residual and/or recurrent deformity and pain. This negatively influenced the activities of daily living and resulted in a significantly poorer outcome within the PODCI. The most important limitation of the study is a smaller number of included subjects and therefore limited power of the study. This long-term, prospective, randomized and controlled trial showed the Ponseti method to be superior to surgical treatment in idiopathic clubfeet. Thanks to better morphology, function, radiological outcomes as well as the patient’s overall health and a better ability to participate in activities of daily living seems Ponseti method be a low cost low-tec technique available for the widest spectrum of patients. http://dx.doi.org/10.1016/j.gaitpost.2015.06.011
Session OS01 Best-Paper-Session – Outcomes Long-term effects of patellar tendon advancement on patella height and proximal tibial growth J. Stout 1,∗ , C. Beimesch 2 , R. Varghese 3 , M. Schwartz 1 , T. Novacheck 1 1
Gillette Children’s Specialty Healthcare, Center for Gait & Motion Analysis, St. Paul, United States 2 Shriners Hospitals for Children-Shreveport, Pediatric Orthopaedic Surgeon, Shreveport, United States 3 Johns Hopkins Children’s Center, Baltimore, United States Research question: What are the long-term effects of PTA prior to skeletal maturity on patella height and proximal tibia growth? Introduction: Correcting extensor lag using patellar tendon advancement (PTA) is an essential aspect of the treatment of crouch gait in children with cerebral palsy (CP). When performed prior to skeletal maturity, the patellar tendon is shaved from the tibial tubercle preserving the proximal tibial growth plate [1,2]. Concerns exist for potential altered growth, early physeal closure, patella baja, and clinical recurvatum [3]. The altered loads
on the skeletally immature anterior tibia have not been fully evaluated. Materials and methods: A retrospective radiographic review was conducted of patients who underwent PTA prior to skeletal maturity. Patients had a minimum of 3 years of expected growth remaining at the time of surgery. All had a diagnosis of CP. Koshino Index (KI) and tibial-physeal angle (TPA) were measured to assess patellar height and growth of the proximal tibia on pre-operative, 3 month post-operative, and yearly follow-up X-rays (minimum 3 years or until skeletal maturity). The change of KI and TPA over time was evaluated. A step-wise linear regression was used for analysis. Predictor variables included: age at surgery, time from surgery, surgery type, amount of deformity, and amount of correction. Results: Thirty-eight patients (average age: 11.6 ± 1.5 years; 23 male, 15 female) met inclusion criteria. Average length of follow-up was 4.3 ± 1.5 years. 83% had reached skeletal maturity at final measurement. All TPA measurements were within typical limits pre-operatively. Average pre-op KI Z-score was 1.3. KI demonstrated an over-correction immediately post-surgery (average −3.3) and remained stable at final follow-up (average −2.9). TPA measurements remained within typical limits for most subjects. Regression analysis revealed main effects for age at surgery, time from surgery, and amount of correction, but not whether DFEO was performed (p < .001). Significant interactions were noted between: (1) age at surgery and time from surgery; (2) age at surgery and amount of correction; and (3) time from surgery and amount of correction (p < .001). Growth arrest was identified in 2 patients (4 knees). The percentage change in TPA between radiographs was greater in those subjects. Seven subjects were noted to exhibit recurvatum in at least one knee after surgery. Recurvatum was not exclusive to change in TPA beyond typical values. Discussion: PTA in patients prior to skeletal maturity is not associated with progressive patella baja, changes in physeal slope or recurvatum with subsequent growth. Change in TPA over time is a useful monitor of proximal tibial growth status after PTA. Age at PTA and amount of correction appear to be predictors for alterations of proximal tibial growth. Conservative management to delay PTA until closer to the end of growth is recommended. References [1] Stout JL, et al. J Bone Joint Surg 2008;90:2470–84. [2] Novacheck TF, et al. J Bone Joint Surg 2009;91(Suppl. 2):71–86. [3] Patthanacharoenphon C, et al. J Child Orthop 2013;7:139–46.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.012
Session OS01 Best-Paper-Session – Outcomes Predicting surgery effect on knee kinematics in cerebral palsy C.O.A. Galarraga 1,∗ , V. Vigneron 2 , B. Dorizzi 3 , N. Khouri 4 , E. Desailly 5 1 Fondation Ellen Poidatz, IBISC, Université d’Evry Val d’Essonne, St Fargeau-Ponthierry, France 2 IBISC, Université d’Evry Val d’Essonne, Courcouronnes, France 3 SAMOVAR, TELECOM SudParis, Evry, France 4 Fondation Ellen Poidatz, Hôpital Necker-Enfants Malades, Paris, France 5 Fondation Ellen Poidatz, St Fargeau-Ponthierry, France
Research question: Can we predict orthopedic surgery effect on knee flexion during gait of cerebral palsy (CP) children?
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Introduction: In order to lessen gait deviations, orthopedic surgery is usually performed on CP patients. Multiple bones and soft tissues are modified during a single-event multilevel surgery (SEMLS), which combines several surgical gestures in the same operation. The objective of this work is to predict postoperative knee flexion during gait of CP children, knowing preoperative gait, physical examination and surgery type. The purpose of the system is to be used as a decision-making tool for SEMLS. Materials and methods: Data is composed of clinical gait analyses and physical examinations of 230 lower limbs corresponding to 115 CP children that have undergone surgery. Missing data belonging to physical examination were replaced using the iterative robust model-based imputation algorithm (IRMI) [1]. The gathered preoperative kinematic and physical examination data were projected into a lower dimension space using principal component analysis (PCA) [2]. Different PCA dimensions were tested. Then a multiple linear regression [3] is performed between postoperative knee flexion during gait and the dimensionality-reduced preoperative vector plus a surgery code. The surgery code is a binary vector whose elements are ‘1’ if a surgery category was conducted and ‘0’ if not. Nine surgery categories are considered: hip bone surgery (BS), hip soft tissue surgery (STS), rectus femoris transfer, hamstring lengthening, patella lowering, distal femoral osteotomy, shank BS, ankle-foot STS and foot BS. Finally the confidence intervals are computed and evaluated for 80% reliability of prediction with the expression: 128 v((SSE/(n − p − 1)) × (1 + x0T (X T X)x0 )), where n is the number of examples, p the number of parameters of the regression, SSE is the sum of quadratic errors per point, x0 is the input vector and X is the matrix with all the input vectors of all available examples. Results: Best results were obtained with a PCA dimension of 9, which contains 82% of the information. On test, the mean RMSE is 8.75◦ (s = 3.9◦ ). The prediction intervals vary from 10◦ to 15◦ depending on the patient and the point of the knee flexion curve. The mean confidence interval is 12◦ . 19.73% of test limbs are outside the prediction intervals. Discussion: The proposed system predicts postoperative knee flexion during gait knowing preoperative state (kinematics and physical exam) and surgery type. The prediction intervals are given with 80% reliability, which is respected when testing new data. The size of these intervals varies depending on preoperative state and surgery type. The system could help clinicians to validate or modify surgical plans and to show the probable outcomes to the patients. References [1] Templ, et al. Iterative stepwise regression imputation using standard and robust methods. Comp Stat Data Anal 2011. [2] Duda, et al. Pattern classification. Wiley; 2012. [3] Bishop. Pattern Recogn Mach Learn; 2006.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.013
Session OS01 Best-Paper-Session – Outcomes Effect of continuous intrathecal baclofen therapy on ambulatory children with cerebral palsy J. Sees ∗ , F. Miller, J. Henley, C. Church, T. Niiler, B. Pruszczynski Nemours Dupont, Wilmington, United States Research question: This study assessed the effects of continuous intrathecal infusion of baclofen (CITB) on the function and gait in ambulatory children with cerebral palsy (CP).
S3
Introduction: CITB is effective in management of severely involved children with CP. However little is known regarding the effect of CITB in ambulatory patients. Materials and methods: Data collected before and after pump implantation were retrospectively analyzed. We compared scores of GMFCS, GMFM-D, step length, velocity, and gait deviation index (GDI). In addition, the usage or discontinuation of CITB was gathered from clinical records. Data were analyzed using oneway ANOVA for multiple comparisons as well as paired sample Wilcoxon test (WT). Results: Twenty-seven ambulatory children with cerebral palsy were included. The mean clinical follow-up for all patients was 5y3m (SD: 2y3m, range 1y–9y7m). The mean follow-up for gait parameters was 2y5m (SD: 1y9m, range 9m–7y6m). Seven patients were quadriplegic, 18 were diplegic, and two were hemiplegic. Five patients had dystonia and 22 patients were spastic or mixed tone. On the pre-op examination the GMFCS level was as follows: 2 patients were level I, 6 level II, 11 level III, and 8 level IV. There was no significant change in the group as a whole in gait velocity or GDI; however, children with less functional impairment, GMFCS I and II, demonstrated significant improvement in function and gait pattern (p < 0.05), GMFM and GDI, while GMFCS levels III and IV showed no significant change post ITB. Discussion: CITB treatment did not significantly change the gait parameters as a whole; however, CITB did change gait parameters for less functionally involved children. Three teenage patients discontinued CITB therapy due to patient complaints of weakness and decreased walking endurance (diplegic pattern, GMFCS II and III). Thus, CITB may not be well tolerated in some CP children who rely on the positive effects of tone for ambulation. CITB continues to have potential for positive effects in ambulatory patients if careful patient selection is considered. The flexibility of dose control and the reversibility of treatment make this therapy very adaptive to patient needs. http://dx.doi.org/10.1016/j.gaitpost.2015.06.014
Session OS02 Rehab Adults Cognitive function and walking speed in older adults performing four walking tasks K. Duffy 1,∗ , J. Jackson 2 , M. Taylor 1 1
University of Essex, School of Biological Science, Colchester, United Kingdom 2 University of Essex, School of Health and Human Sciences, Colchester, United Kingdom Research question: Is there a correlation between walking speed and cognitive function in older adults during different tasks? Introduction: Independent living for older adults is reliant on maintaining cognitive and functional ability (i.e. walking). Older adults with good cognitive function tend to walk faster [1]. However, more complex walking tasks are likely to require higher cognitive abilities which may result in reduced walking speed (WS). This study explored the relationship between cognitive function and WS in older adults performing 4 walking tasks. Materials and methods: 136 community-dwelling older adults aged 55–84 participated. The mini-mental state examination (MMSE) assessed cognitive function prior to data collection. Participants performed 4 tasks: normal walking (NW), carrying a cup of water (dual-task, DT), obstacle clearance (0.10 m × 1.6 m × 0.4 m)
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
foot Study Group score, PODCI = Pediatric outcomes Data Collection Instrument and FRS = Functional Rating Score). Moreover, instrumented 3D gait analysis using the Oxford Foot Model was performed. The results were compared statistically by a nonparametric Mann–Whitney U test. Results: Both groups were comparable at the beginning of treatment with no significant difference in the Pirani score (p = 0.623). After 9.8 years of follow-up the Ponseti group presented superior in morphology (p = 0.024), functional (p = 0.006) as well as radiologic (p = 0.023) evaluation according to ICFSG. Also PODCI (p = 0.016) and FRS (p = 0.005) showed better functional status of children treated with the Ponseti method. Children treated with surgery had more troubles performing sports (p = 0.003) and experienced more pain (p = 0.006), which might also led to inferior results in happiness domain of PODCI (p = 0.03). Moreover, the gait analysis showed deficient hindfoot dorsiflexion (p = 0.039) in the surgical group. The forefoot kinematics did not show any differences between groups. Discussion: The most important finding comparing the longterm outcomes of Ponseti and surgical treatment is the increased stiffness and decreased range of motion at the ankle joint. The most probable reason for that is the scarring. Over time and with longer follow-up studies surgeons began to realize that scarring can lead to stiffness, residual and/or recurrent deformity and pain. This negatively influenced the activities of daily living and resulted in a significantly poorer outcome within the PODCI. The most important limitation of the study is a smaller number of included subjects and therefore limited power of the study. This long-term, prospective, randomized and controlled trial showed the Ponseti method to be superior to surgical treatment in idiopathic clubfeet. Thanks to better morphology, function, radiological outcomes as well as the patient’s overall health and a better ability to participate in activities of daily living seems Ponseti method be a low cost low-tec technique available for the widest spectrum of patients. http://dx.doi.org/10.1016/j.gaitpost.2015.06.011
Session OS01 Best-Paper-Session – Outcomes Long-term effects of patellar tendon advancement on patella height and proximal tibial growth J. Stout 1,∗ , C. Beimesch 2 , R. Varghese 3 , M. Schwartz 1 , T. Novacheck 1 1
Gillette Children’s Specialty Healthcare, Center for Gait & Motion Analysis, St. Paul, United States 2 Shriners Hospitals for Children-Shreveport, Pediatric Orthopaedic Surgeon, Shreveport, United States 3 Johns Hopkins Children’s Center, Baltimore, United States Research question: What are the long-term effects of PTA prior to skeletal maturity on patella height and proximal tibia growth? Introduction: Correcting extensor lag using patellar tendon advancement (PTA) is an essential aspect of the treatment of crouch gait in children with cerebral palsy (CP). When performed prior to skeletal maturity, the patellar tendon is shaved from the tibial tubercle preserving the proximal tibial growth plate [1,2]. Concerns exist for potential altered growth, early physeal closure, patella baja, and clinical recurvatum [3]. The altered loads
on the skeletally immature anterior tibia have not been fully evaluated. Materials and methods: A retrospective radiographic review was conducted of patients who underwent PTA prior to skeletal maturity. Patients had a minimum of 3 years of expected growth remaining at the time of surgery. All had a diagnosis of CP. Koshino Index (KI) and tibial-physeal angle (TPA) were measured to assess patellar height and growth of the proximal tibia on pre-operative, 3 month post-operative, and yearly follow-up X-rays (minimum 3 years or until skeletal maturity). The change of KI and TPA over time was evaluated. A step-wise linear regression was used for analysis. Predictor variables included: age at surgery, time from surgery, surgery type, amount of deformity, and amount of correction. Results: Thirty-eight patients (average age: 11.6 ± 1.5 years; 23 male, 15 female) met inclusion criteria. Average length of follow-up was 4.3 ± 1.5 years. 83% had reached skeletal maturity at final measurement. All TPA measurements were within typical limits pre-operatively. Average pre-op KI Z-score was 1.3. KI demonstrated an over-correction immediately post-surgery (average −3.3) and remained stable at final follow-up (average −2.9). TPA measurements remained within typical limits for most subjects. Regression analysis revealed main effects for age at surgery, time from surgery, and amount of correction, but not whether DFEO was performed (p < .001). Significant interactions were noted between: (1) age at surgery and time from surgery; (2) age at surgery and amount of correction; and (3) time from surgery and amount of correction (p < .001). Growth arrest was identified in 2 patients (4 knees). The percentage change in TPA between radiographs was greater in those subjects. Seven subjects were noted to exhibit recurvatum in at least one knee after surgery. Recurvatum was not exclusive to change in TPA beyond typical values. Discussion: PTA in patients prior to skeletal maturity is not associated with progressive patella baja, changes in physeal slope or recurvatum with subsequent growth. Change in TPA over time is a useful monitor of proximal tibial growth status after PTA. Age at PTA and amount of correction appear to be predictors for alterations of proximal tibial growth. Conservative management to delay PTA until closer to the end of growth is recommended. References [1] Stout JL, et al. J Bone Joint Surg 2008;90:2470–84. [2] Novacheck TF, et al. J Bone Joint Surg 2009;91(Suppl. 2):71–86. [3] Patthanacharoenphon C, et al. J Child Orthop 2013;7:139–46.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.012
Session OS01 Best-Paper-Session – Outcomes Predicting surgery effect on knee kinematics in cerebral palsy C.O.A. Galarraga 1,∗ , V. Vigneron 2 , B. Dorizzi 3 , N. Khouri 4 , E. Desailly 5 1 Fondation Ellen Poidatz, IBISC, Université d’Evry Val d’Essonne, St Fargeau-Ponthierry, France 2 IBISC, Université d’Evry Val d’Essonne, Courcouronnes, France 3 SAMOVAR, TELECOM SudParis, Evry, France 4 Fondation Ellen Poidatz, Hôpital Necker-Enfants Malades, Paris, France 5 Fondation Ellen Poidatz, St Fargeau-Ponthierry, France
Research question: Can we predict orthopedic surgery effect on knee flexion during gait of cerebral palsy (CP) children?
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Introduction: In order to lessen gait deviations, orthopedic surgery is usually performed on CP patients. Multiple bones and soft tissues are modified during a single-event multilevel surgery (SEMLS), which combines several surgical gestures in the same operation. The objective of this work is to predict postoperative knee flexion during gait of CP children, knowing preoperative gait, physical examination and surgery type. The purpose of the system is to be used as a decision-making tool for SEMLS. Materials and methods: Data is composed of clinical gait analyses and physical examinations of 230 lower limbs corresponding to 115 CP children that have undergone surgery. Missing data belonging to physical examination were replaced using the iterative robust model-based imputation algorithm (IRMI) [1]. The gathered preoperative kinematic and physical examination data were projected into a lower dimension space using principal component analysis (PCA) [2]. Different PCA dimensions were tested. Then a multiple linear regression [3] is performed between postoperative knee flexion during gait and the dimensionality-reduced preoperative vector plus a surgery code. The surgery code is a binary vector whose elements are ‘1’ if a surgery category was conducted and ‘0’ if not. Nine surgery categories are considered: hip bone surgery (BS), hip soft tissue surgery (STS), rectus femoris transfer, hamstring lengthening, patella lowering, distal femoral osteotomy, shank BS, ankle-foot STS and foot BS. Finally the confidence intervals are computed and evaluated for 80% reliability of prediction with the expression: 128 v((SSE/(n − p − 1)) × (1 + x0T (X T X)x0 )), where n is the number of examples, p the number of parameters of the regression, SSE is the sum of quadratic errors per point, x0 is the input vector and X is the matrix with all the input vectors of all available examples. Results: Best results were obtained with a PCA dimension of 9, which contains 82% of the information. On test, the mean RMSE is 8.75◦ (s = 3.9◦ ). The prediction intervals vary from 10◦ to 15◦ depending on the patient and the point of the knee flexion curve. The mean confidence interval is 12◦ . 19.73% of test limbs are outside the prediction intervals. Discussion: The proposed system predicts postoperative knee flexion during gait knowing preoperative state (kinematics and physical exam) and surgery type. The prediction intervals are given with 80% reliability, which is respected when testing new data. The size of these intervals varies depending on preoperative state and surgery type. The system could help clinicians to validate or modify surgical plans and to show the probable outcomes to the patients. References [1] Templ, et al. Iterative stepwise regression imputation using standard and robust methods. Comp Stat Data Anal 2011. [2] Duda, et al. Pattern classification. Wiley; 2012. [3] Bishop. Pattern Recogn Mach Learn; 2006.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.013
Session OS01 Best-Paper-Session – Outcomes Effect of continuous intrathecal baclofen therapy on ambulatory children with cerebral palsy J. Sees ∗ , F. Miller, J. Henley, C. Church, T. Niiler, B. Pruszczynski Nemours Dupont, Wilmington, United States Research question: This study assessed the effects of continuous intrathecal infusion of baclofen (CITB) on the function and gait in ambulatory children with cerebral palsy (CP).
S3
Introduction: CITB is effective in management of severely involved children with CP. However little is known regarding the effect of CITB in ambulatory patients. Materials and methods: Data collected before and after pump implantation were retrospectively analyzed. We compared scores of GMFCS, GMFM-D, step length, velocity, and gait deviation index (GDI). In addition, the usage or discontinuation of CITB was gathered from clinical records. Data were analyzed using oneway ANOVA for multiple comparisons as well as paired sample Wilcoxon test (WT). Results: Twenty-seven ambulatory children with cerebral palsy were included. The mean clinical follow-up for all patients was 5y3m (SD: 2y3m, range 1y–9y7m). The mean follow-up for gait parameters was 2y5m (SD: 1y9m, range 9m–7y6m). Seven patients were quadriplegic, 18 were diplegic, and two were hemiplegic. Five patients had dystonia and 22 patients were spastic or mixed tone. On the pre-op examination the GMFCS level was as follows: 2 patients were level I, 6 level II, 11 level III, and 8 level IV. There was no significant change in the group as a whole in gait velocity or GDI; however, children with less functional impairment, GMFCS I and II, demonstrated significant improvement in function and gait pattern (p < 0.05), GMFM and GDI, while GMFCS levels III and IV showed no significant change post ITB. Discussion: CITB treatment did not significantly change the gait parameters as a whole; however, CITB did change gait parameters for less functionally involved children. Three teenage patients discontinued CITB therapy due to patient complaints of weakness and decreased walking endurance (diplegic pattern, GMFCS II and III). Thus, CITB may not be well tolerated in some CP children who rely on the positive effects of tone for ambulation. CITB continues to have potential for positive effects in ambulatory patients if careful patient selection is considered. The flexibility of dose control and the reversibility of treatment make this therapy very adaptive to patient needs. http://dx.doi.org/10.1016/j.gaitpost.2015.06.014
Session OS02 Rehab Adults Cognitive function and walking speed in older adults performing four walking tasks K. Duffy 1,∗ , J. Jackson 2 , M. Taylor 1 1
University of Essex, School of Biological Science, Colchester, United Kingdom 2 University of Essex, School of Health and Human Sciences, Colchester, United Kingdom Research question: Is there a correlation between walking speed and cognitive function in older adults during different tasks? Introduction: Independent living for older adults is reliant on maintaining cognitive and functional ability (i.e. walking). Older adults with good cognitive function tend to walk faster [1]. However, more complex walking tasks are likely to require higher cognitive abilities which may result in reduced walking speed (WS). This study explored the relationship between cognitive function and WS in older adults performing 4 walking tasks. Materials and methods: 136 community-dwelling older adults aged 55–84 participated. The mini-mental state examination (MMSE) assessed cognitive function prior to data collection. Participants performed 4 tasks: normal walking (NW), carrying a cup of water (dual-task, DT), obstacle clearance (0.10 m × 1.6 m × 0.4 m)