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Supervised classification of the effect of hamstrings lengthening in cerebral palsy children after single event multilevel surgery
ESMAC 2012 abstract / Gait & Posture 38 (2013) S1–S116
Reference [1] Ma FY, Selber P, Nattrass GR, Harvey AR, Wolfe R, Graham HK. Lengthening and transfer of hamstrings for a flexion deformity of the knee in children with bilateral cerebral palsy. Journal of Bone and Joint Surgery – British Volume 2006;88B:248–54.
http://dx.doi.org/10.1016/j.gaitpost.2013.07.078 O65 Supervised classification of the effect of hamstrings lengthening in cerebral palsy children after single event multilevel surgery
S39
validation and 6.5% in generalization. In view of the classification system 1/3 of G1 LL were not improved by HL. Discussion and conclusions: This supervised classification and data conditioning techniques are able to categorize the specific effect of HL among all the associated performed procedures in two classes “positive effect” and “not-positive effect”. While 83% of patients were improved by SEMLS, HL had positively contributed to this improvement in only 70% of these cases. This methodology can be generalized to study the effect of other surgical procedures.
Reference [1] Schwartz M., Rozumalski A., Gait and Posture, 28(3), 351–357.
Eric Desailly 1 , Abdennour Sebsadji 1 , Daniel Yepremian 1 , Khalifa Djemal 2 , Philippe Hoppenot 2 , Néjib Khouri 3,1
http://dx.doi.org/10.1016/j.gaitpost.2013.07.079 O66
1 Fondation Ellen Poidatz, Motion Analysis Unit, St Fargeau Ponthierry, France 2 Université d’Evry, IBISC, Evry, France 3 Armand Trousseau Hospital, Department of Pediatric Orthopaedic Surgery, Paris, France
Proximal rectus femoris release does not influence the effects of distal rectus femoris transfer on the knee in cerebral palsy
Introduction: Single event multilevel surgery (SEMLS) purpose is to improve the cerebral palsy (CP) children’s gait by associating multiple surgeries on the same therapeutic time. It is therefore complex to isolate the effect of these actions in this multifocal context. To address this problem we chose to specifically identify the effect of hamstrings lengthening (HL) in CP children with crouch gait. The aims of this study were to describe the specific parameters influenced by HL and to classify the positive or not-positive effect of HL in SEMLS. Patients/materials and methods: 42 CP children (12 ± 3 years) were divided into two groups: 31 (G1 = 60 lower limbs (LL)) and 11 (G2 = 20 LL), respectively having followed and not-followed HL among all the associated surgeries. All patients had clinical gait analysis before and 1.9 ± 0.8 years after surgery. The GDI is calculated [1]. All kinematic data (angles, velocities) were doublenormalized and conditioned in two vectors. A homogeneity test (G1 vs G2) selected the kinematic parameters influenced by HL (t-test, p < 0.005). Principal component analysis identified the minimum descriptors characterizing the effect of HL. Several classifiers (Regularized Discriminant Analysis (RDA) and linear or nonlinear Support Vector Machines (SVM)) were supervised by 6 experts’ opinions. Experts’ opinions were based on video and kinematic curves comparison between pre and post-surgery conditions. The classifiers performances in learning, validation (leave one out) and generalization were compared. Results: GDI results showed that 83% of the subjects of G1 were globally improved by SEMLS. Among all the kinematic data, 16 sub-vectors, significantly influenced by HL were selected. Their dimensionality was reduced by principal component analysis. The 6 experts have classified the effect of HL for 37 LL: 24 were positive and 13 not-positive. The classification method with the best performance was the linear SVM with error rate 0% in learning, 5.4% in
Dóra Vegvari 1 , Sebastian I. Wolf 2 , Daniel Heitzmann 2 , Frank Braatz 2 , Matthias Klotz 2 , Thomas Dreher 2 1 Semmelweis University, Department of Orthopaedics, Budapest, Hungary 2 Heidelberg University Clinics, Department for Orthopedics and Trauma Surgery, Heidelberg, Germany
Introduction: Dysfunction of the biarticular rectus femoris (RF) muscle is common among CP children [1,2]. While the proximal part works as a hip flexor, the distal part extends the knee [3]. In CP children with increased anterior pelvic tilt and hip flexion contracture proximal RF release was considered [4]. At the knee, pathological RF activation leads to stiff knee gait, which is commonly treated by distal rectus femoris transfer (DRFT) [1,2]. The benefits after DRFT for knee joint motion are well described. However, no reports evaluated if a concomitant proximal RF release affects the knee kinematics. Patients/materials and methods: In a matched pair analysis, the short- and long-term outcome of 20 patients with spastic diplegic cerebral palsy, who were treated with DRFT and concomitant proximal RF release (RTRR group) was compared with the outcome of 20 patients, in which DRFT but no proximal RF release (RT group) was done. The matching criteria included: maximum knee flexion in swing and ROM in swing as well as age at surgery, BMI and GGI. Standardized three-dimensional gait analysis was done before (E0), 1 year (E1) and 8–9 years (E2; RT: 8.1 ± 2.1; RTRR: 9.2 ± 2.2) after surgery. Results: Knee kinematics no group differences were found at any examination (Table 1). Peak knee flexion in swing (pKFSw) showed a slight but not significant increase in both groups at E1. While this was maintained in RTRR group at E2, there was a minimal
Table 1 Gait analysis outcome. RT
Mean anterior pelvic tilt pKFSw Timing of pKFSw Knee ROM in swing Knee flexion velocity
[deg.] [deg.] [%GC] [deg] [deq./%GCl
RTRR
Group diff
E0
E1
E2
E0
E1
E2
167) 52(12) 81()4 22(8) 0.8(0.4)
19(7) 55(8) 79 (5)* 37(10)* 1.2(0.4)*
17(9) 53(10) 78 (3)* 34(11)* 1.0 (0.5)*
20(7) 51 (10) 80 (5) 22 (8) 0.8 (0.3)
22(7) 54(9) 78(5) 37(10)* 1.2 (0.4)*
20(7) 55(8) 78(5) 33(10)* 1.0(0–6)*
Two-way ANOVA: * significant difference from E0, pKFSw [peak knee flexion in swing). ROM (range of motion).
E0,E1 – – – –
Reference [1] Ma FY, Selber P, Nattrass GR, Harvey AR, Wolfe R, Graham HK. Lengthening and transfer of hamstrings for a flexion deformity of the knee in children with bilateral cerebral palsy. Journal of Bone and Joint Surgery – British Volume 2006;88B:248–54.
http://dx.doi.org/10.1016/j.gaitpost.2013.07.078 O65 Supervised classification of the effect of hamstrings lengthening in cerebral palsy children after single event multilevel surgery
S39
validation and 6.5% in generalization. In view of the classification system 1/3 of G1 LL were not improved by HL. Discussion and conclusions: This supervised classification and data conditioning techniques are able to categorize the specific effect of HL among all the associated performed procedures in two classes “positive effect” and “not-positive effect”. While 83% of patients were improved by SEMLS, HL had positively contributed to this improvement in only 70% of these cases. This methodology can be generalized to study the effect of other surgical procedures.
Reference [1] Schwartz M., Rozumalski A., Gait and Posture, 28(3), 351–357.
Eric Desailly 1 , Abdennour Sebsadji 1 , Daniel Yepremian 1 , Khalifa Djemal 2 , Philippe Hoppenot 2 , Néjib Khouri 3,1
http://dx.doi.org/10.1016/j.gaitpost.2013.07.079 O66
1 Fondation Ellen Poidatz, Motion Analysis Unit, St Fargeau Ponthierry, France 2 Université d’Evry, IBISC, Evry, France 3 Armand Trousseau Hospital, Department of Pediatric Orthopaedic Surgery, Paris, France
Proximal rectus femoris release does not influence the effects of distal rectus femoris transfer on the knee in cerebral palsy
Introduction: Single event multilevel surgery (SEMLS) purpose is to improve the cerebral palsy (CP) children’s gait by associating multiple surgeries on the same therapeutic time. It is therefore complex to isolate the effect of these actions in this multifocal context. To address this problem we chose to specifically identify the effect of hamstrings lengthening (HL) in CP children with crouch gait. The aims of this study were to describe the specific parameters influenced by HL and to classify the positive or not-positive effect of HL in SEMLS. Patients/materials and methods: 42 CP children (12 ± 3 years) were divided into two groups: 31 (G1 = 60 lower limbs (LL)) and 11 (G2 = 20 LL), respectively having followed and not-followed HL among all the associated surgeries. All patients had clinical gait analysis before and 1.9 ± 0.8 years after surgery. The GDI is calculated [1]. All kinematic data (angles, velocities) were doublenormalized and conditioned in two vectors. A homogeneity test (G1 vs G2) selected the kinematic parameters influenced by HL (t-test, p < 0.005). Principal component analysis identified the minimum descriptors characterizing the effect of HL. Several classifiers (Regularized Discriminant Analysis (RDA) and linear or nonlinear Support Vector Machines (SVM)) were supervised by 6 experts’ opinions. Experts’ opinions were based on video and kinematic curves comparison between pre and post-surgery conditions. The classifiers performances in learning, validation (leave one out) and generalization were compared. Results: GDI results showed that 83% of the subjects of G1 were globally improved by SEMLS. Among all the kinematic data, 16 sub-vectors, significantly influenced by HL were selected. Their dimensionality was reduced by principal component analysis. The 6 experts have classified the effect of HL for 37 LL: 24 were positive and 13 not-positive. The classification method with the best performance was the linear SVM with error rate 0% in learning, 5.4% in
Dóra Vegvari 1 , Sebastian I. Wolf 2 , Daniel Heitzmann 2 , Frank Braatz 2 , Matthias Klotz 2 , Thomas Dreher 2 1 Semmelweis University, Department of Orthopaedics, Budapest, Hungary 2 Heidelberg University Clinics, Department for Orthopedics and Trauma Surgery, Heidelberg, Germany
Introduction: Dysfunction of the biarticular rectus femoris (RF) muscle is common among CP children [1,2]. While the proximal part works as a hip flexor, the distal part extends the knee [3]. In CP children with increased anterior pelvic tilt and hip flexion contracture proximal RF release was considered [4]. At the knee, pathological RF activation leads to stiff knee gait, which is commonly treated by distal rectus femoris transfer (DRFT) [1,2]. The benefits after DRFT for knee joint motion are well described. However, no reports evaluated if a concomitant proximal RF release affects the knee kinematics. Patients/materials and methods: In a matched pair analysis, the short- and long-term outcome of 20 patients with spastic diplegic cerebral palsy, who were treated with DRFT and concomitant proximal RF release (RTRR group) was compared with the outcome of 20 patients, in which DRFT but no proximal RF release (RT group) was done. The matching criteria included: maximum knee flexion in swing and ROM in swing as well as age at surgery, BMI and GGI. Standardized three-dimensional gait analysis was done before (E0), 1 year (E1) and 8–9 years (E2; RT: 8.1 ± 2.1; RTRR: 9.2 ± 2.2) after surgery. Results: Knee kinematics no group differences were found at any examination (Table 1). Peak knee flexion in swing (pKFSw) showed a slight but not significant increase in both groups at E1. While this was maintained in RTRR group at E2, there was a minimal
Table 1 Gait analysis outcome. RT
Mean anterior pelvic tilt pKFSw Timing of pKFSw Knee ROM in swing Knee flexion velocity
[deg.] [deg.] [%GC] [deg] [deq./%GCl
RTRR
Group diff
E0
E1
E2
E0
E1
E2
167) 52(12) 81()4 22(8) 0.8(0.4)
19(7) 55(8) 79 (5)* 37(10)* 1.2(0.4)*
17(9) 53(10) 78 (3)* 34(11)* 1.0 (0.5)*
20(7) 51 (10) 80 (5) 22 (8) 0.8 (0.3)
22(7) 54(9) 78(5) 37(10)* 1.2 (0.4)*
20(7) 55(8) 78(5) 33(10)* 1.0(0–6)*
Two-way ANOVA: * significant difference from E0, pKFSw [peak knee flexion in swing). ROM (range of motion).
E0,E1 – – – –