Aim. The aim of the study was to characterise gait in patients with achondroplasia post lengthening. Patients/Materials and Methods. Full kinematic and kinetic lower limb gait analysis was performed at the Sheffield Children's Hospital gait laboratory, Sheffield, using a Vicon system (6 cameras working at 50Hz) and processed using Plug In Gait modelling software. The lengthened Achondroplasia group (n=11, mean age = 24.5 ± 6.1) had previously undergone surgical lengthening of the legs. The lengthened Achondroplasia group was compared to a control group of 11 adult normal subjects. Results. Averaged sagittal plane kinematics are shown in Figure 1. The key sagittal plane characteristics we found were increased anterior pelvic tilt (Achondroplasia mean = 22.2 ± 7.1°, normal mean = 14.2 ± 5.3°), decreased peak hip extension (Achondroplasia = 10.5 ± 11.2°, normal = −5.8 ± 5.3°), increased peak hip flexion (Achondroplasia = 49.3 ± 9.8°, normal = 40.0 ± 5.2°), and reduced knee extension in midstance (Achondroplasia = 14.0 ± 8.5°, normal = 4.4 ± 8.5°) At the ankle the mean of the lengthened Achondroplasia group lies within one standard deviation of the normal dataset throughout the gait cycle. Summary and Conclusions. Three dimensional gait analysis of people with Achondroplasia following lower limb-lengthening surgery showed characteristic Achondroplasic gait, that is: increased anterior pelvic tilt, reduced hip extension and increased hip flexion. The group of lengthened Achondroplasia participants also failed to extend the knees fully in midstance. At the ankle the sagittal plane kinematics were within one standard deviation of the normal dataset

Aims

The purpose of this study was to evaluate the long-term outcome of adolescents with cerebral palsy who have undergone single-event multilevel surgery for a flexed-knee gait, followed into young adulthood using 3D motion analysis.

Between July 2000 and April 2004, 19 patients with bilateral spastic cerebral palsy who required an assistive device to walk had combined lengthening-transfer of the medial hamstrings as part of multilevel surgery. A standardised physical examination, measurement of the Functional Mobility Scale score and video or instrumented gait analysis were performed pre- and post-operatively. Static parameters (popliteal angle, flexion deformity of the knee) and sagittal knee kinematic parameters (knee flexion at initial contact, minimum knee flexion during stance, mean knee flexion during stance) were recorded. The mean length of follow-up was 25 months (14 to 45).

Statistically significant improvements in static and dynamic outcome parameters were found, corresponding to improvements in gait and functional mobility as determined by the Functional Mobility Scale. Mild hyperextension of the knee during gait developed in two patients and was controlled by adjustment of their ankle-foot orthosis. Residual flexion deformity > 10° occurred in both knees of one patient and was treated by anterior distal femoral physeal stapling. Two children also showed an improvement of one level in the Gross Motor Function Classification System.

This study compares the initial outcomes of minimally invasive techniques for single-event multi-level surgery with conventional single-event multi-level surgery. The minimally invasive techniques included derotation osteotomies using closed corticotomy and fixation with titanium elastic nails and percutaneous lengthening of muscles where possible. A prospective cohort study of two matched groups was undertaken. Ten children with diplegic cerebral palsy with a mean age of ten years six months (7.11 to 13.9) had multi-level minimally invasive surgery and were matched for ambulatory level and compared with ten children with a mean age of 11 years four months (7.9 to 14.4) who had conventional single-event multi-level surgery. Gait kinematics, the Gillette Gait Index, isometric muscle strength and gross motor function were assessed before and 12 months after operation.

The minimally invasive group had significantly reduced operation time and blood loss with a significantly improved time to mobilisation. There were no complications intra-operatively or during hospitalisation in either group. There was significant improvement in gait kinematics and the Gillette Gait Index in both groups with no difference between them. There was a trend to improved muscle strength in the multi-level group. There was no significant difference in gross motor function between the groups.

We consider that minimally invasive single-event multi-level surgery can be achieved safely and effectively with significant advantages over conventional techniques in children with diplegic cerebral palsy.