Cerebral palsy (CP) is a neural condition that impacts and impairs the musculoskeletal system. Skeletal muscles, particularly in the lower limb, have previously been shown to be significantly reduced in volume in CP compared to typical controls. Muscle volume is a gross measure, however, and does not capture shape characteristics which—if quantified—could offer a robust and novel assessment of how this condition impacts skeletal muscle form and function in CP. In this study, we used mathematical shape modelling to quantify not just size, but also the shape, of soleus muscles in CP and typically developing (TD) cohorts to explore this question.

Shape modelling is a mathematical technique used previously for bones, organs, and tumours. We obtained segmented muscle data from prior MRI studies in CP. We generated shape models of CP and TD cohorts and used our shape models to assess similarities and differences between the cohorts, and we statistically analysed shape differences.

The shape models revealed similar principal components (PCs), i.e. the defining mathematical features of each shape, yet showed greater shape variability within the CP cohort. The model revealed a distinct feature (a superior –> inferior shift of the broad central region), indicating the model could identify muscular features that were not apparent with direct observation. Two PCs dominated the differences between CP and TD cohorts: size and aspect ratio (thinness) of the muscle.

The distinct appearance characteristic in the CP model correspond to specific muscle impairments in CP to be discussed further. Overall, children with CP had smaller muscles that also tended to be long, thin, and narrow. Shape modelling captures shape features quantitatively, which indicate the ways that muscles are being impacted in CP. In the future, we hope to tailor this technique toward informing diagnosis and treatments in CP.

Cannulated screw fixation is currently the treatment of choice for slipped capital femoral epiphyses (SCFE). A SCFE module of the Bonedoc simulator was created in order to test the ability of advanced trainees to place the screw in the correct position, and the practicality of using the simulator within the orthopaedic surgery training curriculum.

Bonedoc (University of Auckland) is a virtual reality simulator of image guided orthopaedic operations1. This simulator runs in Internet Explorer (Microsoft, USA) using the Octaga (Octaga, Norway) plugin. The total download is around 4 MB. The SCFE module was created from a CT scan of a Grade 2 acute on chronic SCFE. DICOM images were imported into 3DView (www.rmrsystems.co.uk) and a mesh created. The generic femur from the DHS module was morphed within the CAD package Blender (Blender.org) to conform to this reconstructed SCFE mesh.

Forty two advanced trainees operated on the same virtual SCFE during a training weekend. The trainees had 25 minutes to become familiar with the simulator and complete the operative case. The trainees performed all tasks relevant to the operation. At the operation’s conclusion the trainees self-assessed their performance. Subsequently the simulator provided surgically relevant objective feedback on aspects such as exact position of the screw, misplaced attempts and the number of x-rays. The results were analysed using SAS (SAS Institute, USA) in subgroups based on year on the scheme, as well as correlated within each operation.

There was no difference in the accuracy with which the virtual slipped capital femoral epiphysis was pinned by trainees in different years in the training programme. However, 26 of the 39 of the virtual screws were placed in the superior direction. There was no correlation between number of X-ray images taken and final accuracy of screw placement. The number of misplaced drill holes was correlated both with number of X-ray images taken (p< 0.01) and operative time (p< 0.01) but not with final accuracy of the screw. An increase in misplaced attempts was correlated with angulation errors in the anterior plane (p< 0.01). There was no correlation between the trainees’ self assessment and any of the measured variables.

The Bonedoc simulator provides a means to test trainees on technical aspects of a surgical procedure. It provides objective results, which can mimic real world outcomes. In addition, the ability to test all trainees on the same virtual operative case allows standardisation of assessment. All trainees completed the task to a similar level of accuracy, which may reflect the overall skill level in advanced trainees within the New Zealand. However, many trainees placed the screw in the superior portion of the femoral head, which is thought to increase the risk of avascular necrosis2. Further work is required to evaluate how accurately performance on the simulator predicts performance in the operating theatre

The aim of this study was to investigate upper limb botulinum toxin A (BTX-A) injections in children with spastic hemiplegia.

Ten children with hemiplegia, aged 10–17 years, received upper limb BTX-A injections and 6 weeks therapy. BTX-A was injected using EMG guidance into elbow and wrist flexors, and forearm pronators (dose 1–2 units/kg body wt (Botox®) per muscle). Follow-up assessments continued to 24 weeks post BTX-A. Outcome measures included three-dimensional (3-D) upper limb analysis of functional tasks, Melbourne Assessment; passive range of motion (PROM), and muscle tone.

There were no serious adverse effects. Elbow flexor muscle tone was reduced to 12 weeks post BTX-A (p < 0.05). Mean passive elbow supination increased by 19 degrees (not significant, p= 0.3). Pre-injection 3-D analysis showed that, compared to controls, children with hemiplegia were slower at performing upper limb reaching tasks, using less elbow extension and supination, and utilising increased compensatory trunk forward flexion. Post BTX-A, the time to complete upper limb tasks did not change (p> 0.15). However, at least six subjects had increased elbow extension (average 17 degrees) and decreased trunk forward flexion (average 16 degrees) during upper limb reaching tasks. Five subjects improved their Melbourne Assessment score by 5% or greater.

Decreased tone and individual improvements in upper limb functional tasks were seen post BTX-A and therapy. However deficits in timing of upper limb movements did not change post BTX-A.

We studied the results of multi-level surgical intervention for children with cerebral palsy.

Thirty patients, aged 7–16 years, with spastic diplegia (n=20), or spastic hemiplegia (n=10) were studied prospectively by gait analysis. Multilevel surgery included a combination of psoas lengthening, medial hamstring lengthening, rectus femoris transfer and gastrocnemius lengthening +/− foot surgery or femoral derotation osteotomies. Gait analyses were carried out pre-op and at 6 and 24 months post-op.

Children with spastic diplegia increased their walking velocity by an average of 20% at two years (p< 0.05). Mean stride length increased from 89cm pre-op to 102cm at two years (p< 0.05) with similar improvements in both groups of children. Maximum knee extension in stance improved from an average 17.5 degrees flexion pre-operatively to an average 5 degrees flexion postoperatively (p< 0.05). Peak knee flexion in swing was maintained and the timing improved. Peak ankle dorsiflexion in stance was unchanged following surgery but the timing of peak ankle dorsiflexion was normalised to late stance (from 24% of cycle pre-operatively to 48% of cycle post-operatively (norm = 48%). Average maximum hip extension in stance did not change. The mean anterior pelvic tilt did not change post-operatively. However, a number of children with spastic diplegia had increased anterior pelvic tilt post-operatively.

These results are similar to those reported internationally, with most improvement seen distally at the knee and ankle and less improvement at the hip. Increased anterior pelvic tilt was seen as a consequence of hamstring lengthening in some more involved patients.

Femoral fractures are a common injury in the paediatric population. The purpose of this study was to audit the cost and early outcomes of femur fractures treated at the Starship Childrens Hospital

Forty-eight femur fractures treated between January 1998 and December 2002 were reviewed. 25 fractures were treated by application of an early hip spica, 12 by IM nails and 11 by other methods.

Children treated by early hip spica averaged 3.8 years in age. They went to theatre an average of 29.1 hours after admission and had an average length of stay of 3.8 days. In the 30 days after discharge, five patients were readmitted for loss of fracture position.

Children treated with IM elastic nails averaged 9.5 years and went to theatre on average 35.1 hours after admission. Their length of stay averaged 8.3 days. Complications in hospital included return to theatre to shorten a wire (1 patient), remanipulation and application of a hip spica (2 patients) and difficulty mobilizing (1 patient). In the first 30 days after discharge, two patients required readmission for further surgery due to prominence of the wire.

Children treated with external fixator (7), femoral rod (1) or crossed k-wires (3) averaged 8.7 years in age. They went to theatre on average 58 hours after injury and had an average length of stay of 24 days. Two patients were readmitted with superficial pin-site infections.

Most femur fractures are being operated on the next day, however surgery is delayed in some patients. The readmission rate in the first 30 days is significant and is not reduced by operative fixation. Cost containment should focus on ways to reduce the early readmission rate.

The purpose of the study was to document the outcome in adulthood of treatment for idiopathic toe walking.

Twenty of 23 adults who had been previously treated for idiopathic toe walking from 1984 to 1990 were contacted. Three of the 20 subjects lived outside Auckland and four subjects declined to participate, giving a total of 13 subjects suitable for study. All but one of the subjects had had serial casts between the ages of 3.7 to 9.5 years. Six subjects had no further treatment while the other seven subjects went on to surgical lengthening of either TA or calf (average age 10.7 years). All participants underwent 3-D gait analysis and heel-rise test. Average follow-up was 10.8 years (range 5.4–15.6 years). Three patients still had signs of toe walking on visual observation of their gait. The maximum ankle dorsiflexion in stance averaged 90 on 3-D gait analysis (range 20 to 140). Eleven subjects showed maximum ankle dorsiflexion in stance greater than 2 standard deviations below normative values. Nine subjects had abnormal timing of maximal ankle dorsiflexion in stance with maximum ankle dorsiflexion prior to 50 percent of the gait cycle. Only two patients had ankle push off powers below normative values of 2 watts/kg.

This is the first study to report on adults treated for idiopathic toe- walking as children. Most subjects showed restricted range and altered timing of ankle dor-siflexion in gait, however this was detectable visually in only three subjects.

Prophylactic pinning of the contralateral hip remains controversial in the management of unilateral SUFE. This paper reviews our experience, with particular reference to the fate of the non-operated hip.

We reviewed the charts and radiographs of 218 patients who were admitted to Starship Children’s Hospital between 1988 and 2000 with a diagnosis of SUFE. Of the 211 patients with data sufficient for analysis, 168 (80%) had unilateral hip pinning and 43 (20%) had bilateral pinning. 32.8% of patients with a unilateral slip were subsequently readmitted for pinning of the contralateral hip. The time between the two operations averaged 7.5 months and did not vary with race or gender. European females had an almost 50% readmission rate for pinning of the opposite hip while Maori females had the lowest readmission rate (15%). All European females less than 11.5 years with unilateral slips returned for pinning of the opposite hip. 28 of the initial unilateral hip pinnings were for an unstable SUFE. Only 8 of the 28 patients were readmitted for pinning of the opposite hip, all with stable slips. Only one patient with a stable first slip presented with an unstable second slip.

Despite a high incidence of bilateralism, this study shows that it is very uncommon for a patient to present with an unstable second slip. Prophylactic pinning can have complications. We therefore recommend follow-up rather than prophylactic pinning for patients presenting with unilateral SUFE. Caucasian females less than 11.5 years represent a group at high risk of a second slip.

We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild osteogenesis imperfecta with an age- and sex-matched control group. The patients had only mild clinical symptoms but DEXA detected highly significant differences in BMD between them and the controls. The mean BMD in the children with osteogenesis imperfecta was 76.7% of normal in the lumbar spine (p < 0.001) and 71.2% of normal in the femoral neck (p < 0.001). DEXA is an objective, reproducible and sensitive method of measurement of BMD in children. It may help to establish the diagnosis, to assess prognosis and possibly to monitor the response to different types of treatment.