Due to abnormal neuromuscular development, functional capability in children with cerebral palsy is often severely compromised. Single event multi-level surgery (SEMLS) is the gold standard surgical treatment for patients with cerebral palsy. It has been demonstrated to improve gait, however, how standing posture is affected is unknown.

The aim was to investigate the effect of SEMLS in patients with spastic cerebral palsy on walking and standing posture using 3D gait analysis.

Participants were identified from the One Small Step Gait Laboratory database. Standardised 3D-Gait analysis was performed within 2 years pre- and post-SEMLS. Gait abnormality was measured using the Gait Profile Score (GPS) index; standing abnormality was measured using the newly-developed Standing Profile Score (SPS) index. A control group (n=20) of age/sex-matched CP patients who did not undergo surgery were also assessed.

104 patients (73 boys, 31 girls) with spastic cerebral palsy underwent SEMLS with appropriate pre- and post-gait analyses (2000–2015). 91 patients had bilateral limb involvement, 14 had unilateral limb involvement. Average age at surgery was 10.38 years (range 4.85–15.60 years). A total of 341 procedures were performed, with hamstring and gastrocnemius lengthening representing approximately 65% of this.

There was a 20% mean improvement in walking (GPS reduced 2.4°, p<0.001) and standing (SPS reduced 3.4°, p<0.001) following SEMLS. No improvement was noted in the control group. Significant correlations were observed between the changes in SPS and GPS following surgery (r2, p<0.001). Patients with poorer pre-operative standing posture (SPS) reported the most significant improvement following surgery.

We confirmed improvement in walking following SEMLS using the Gait Profile Score (GPS). This is the first paper to report that standing posture is also improved following surgery using a novel index, the Standing Posture Score (SPS). SPS could be adopted as a tool to assess functional capability and predict post-operative changes.

The standard approach of diagnosing and monitoring scoliosis involves using the Cobb angle from posteroanterior (PA) radiograph. This approach has two key limitations: 1) It involves exposing the patients to ionising radiation during a period of heightened radiosensitivity. 2) The 2D x-ray image is a projection image of a 3D deformity and the Cobb angle represents only lateral rotation. 3DUS would overcome both these limitations.

We developed a 3DUS system by combining motion capture technology, a conventional 2D ultrasound scanner and bespoke software. An ex vivo experiment and a pilot clinical study were carried out to demonstrate the system's ability in identifying vertebrae landmarks and quantifying the curvature. For the ex vivo validation, a spine phantom was created by 3D-printing a segmented abdo-pelvis CT scan. The spine phantom was then scanned using 3DUS and the level of agreement in the dimensions measured using 3DUS and CT was assessed. An 11 year old female with adolescent idiopathic scoliosis (AIS) was scanned with 3DUS. The SP co-ordinates were projected on a plane of best-fit to compare the curvature angle from 3DUS with the Cobb angle from the x-ray image.

The spinous (SP), transverse processes and the laminae demonstrated high echogenicity and were easily identifiable. The difference between the spine phantom inter-SP dimension measurements made in 3DUS and CT was <2.5%. The PA x-ray of the AIS patient revealed 47° (L4-T11) and 52° (T6-T11) curves. 3DUS was able to represent the deformity in 3D revealing complex curvatures in all planes. The curvature angle from derived from 3DUS for the L4-T11 and T6-T11 curves were 132° (48°) and 125° (55°) respectively.

The results of this pilot study demonstrate 3DUS as a promising tool for imaging spine curvature

Ambulating children with bilateral spastic cerebral palsy (BSCP) demonstrate atypical posture and gait due to abnormal muscle and skeletal growth when compared to typically–developing (TD) children. Normal postural alignment in standing facilitates many of the tasks of daily living because it allows a stable base of support without requiring significant muscular effort. Similarly, increasing gait abnormality is associated with poorer functional capacity. Our aims were to compare the standing posture of TD children and children with BSCP using the Standing Profile Score and identify if any abnormality in standing is correlated with abnormality in walking in children with BSCP using the Gait Profile Score index.

We retrospectively compared 44 typically-developing children to 74 age-matched children with BSCP (GMFCS I & II). We performed 3D Gait Analysis during long-standing (10seconds) and in gait after application of 16 retro-reflective markers on anatomical landmarks of the lower limb and pelvis. Analysis of all kinematics was performed for movements in the sagittal, coronal and axial planes. The Gait Profile score (GPS) is a validated index of overall gait pathology. The Standing Profile Score (SPS) was developed using the same calculations for GPS but during static trials.

A significant correlation was observed between the Standing Profile Score (SPS) and Gait Profile Score (GPS) in children with BSCP (p<0.001). Significant differences were exhibited in GPS between the two groups, across all parameters, except the pelvic obliquity (p<0.05). A significant positive correlation existed for hip rotation in both groups, however the correlations observed at hip flexion and ankle dorsiflexion were significantly greater in the BSCP group compare to the TD group (p<0.01).

We have shown that posture during gait (GPS) is predictable from standing posture (SPS) in patients with BSCP. This biomechanical relationship can aid surgical decision-making.