Hip displacement in children with cerebral palsy in Scotland: a total population study

PURPOSE

The purpose of this study is to report the number of children from a total population of children with cerebral palsy (CP) in Scotland who had a displaced or dislocated hip at first registration in a national surveillance programme.

METHODS

Migration percentage (MP), laterality, Gross Motor Function Classification System (GMFCS) level, CP subtype, distribution of CP and age were analyzed in 1171 children. Relative risk was calculated with 95% confidence intervals. Hip displacement and dislocation were defined as a MP of 40 to 99 and > 100 respectively.

RESULTS

Radiographs were available from the first assessment of 1171 children out of 1933 children registered on the system. In all, 2.5% of children had either one or both hips dislocated (29/1171) and dislocation only occurred in children of GMFCS levels IV and V. A total of 10% of children had a MP 40 to 99 in one or both hips (117/1171). An increasing GMFCS level was strongly associated with an abnormal MP. Hip dislocation was unusual in patients under the age of seven years. A MP of 40 to 99 was not seen in children with isolated dystonia. Displacement was more frequent in children with bilateral involvement and dislocation was only seen in spastic and mixed tone groups.

CONCLUSION

This data gives an overview of the number of CP children who have hip displacement/dislocation in Scotland and who will possibly require surgery.

LEVEL OF EVIDENCE

I.

The head shaft angle is associated with hip displacement in children at GMFCS levels III-V - a population based study

Background

An increased Head Shaft Angle (HSA) has been reported as a risk factor for hip displacement in children with cerebral palsy (CP) but opinions differ in the literature. The purpose of this study was to re-evaluate the relationship between HSA and hip displacement in a different population of children with CP.

Methods

The Cerebral Palsy Integrated Pathway Scotland surveillance programme includes 95% of all children with CP in Scotland. The pelvic radiographs from 640 children in GMFCS levels III-V were chosen. The most displaced hip was analysed and the radiographs used were those taken at the child’s first registration in the database to avoid the potential effects of surveillance on subsequent hip centration. A logistic regression model was used with hip displacement (migration percentage [MP] ≥40%) as outcome and HSA, GMFCS, age and sex as covariates.

Results

The MP was ≥40% in 118 hips with a mean HSA of 164° (range 121–180°) and < 40% in 522 hips with a mean HSA of 160° (range 111–180°). The logistic regression analysis showed no significant influence of age and sex on MP in this population but a high GMFCS level was strongly associated with hip displacement. An increased HSA was also associated with hip displacement, a 10° difference in HSA for children adjusted for age, sex, and GMFCS gave an odds ratio of 1.26 for hip displacement equal or above 40% (p = 0.009) and hips with HSA above 164.5 degrees had an odds ratio of 1.96 compared with hips with HSA below 164.5 degrees (p = 0.002).

Conclusion

These findings confirm that HSA is associated with hip displacement in children in GMFCS levels III-V.

A cohort study of tibialis anterior tendon shortening in combination with calf muscle lengthening in spastic equinus in cerebral palsy

The aim of this study was to evaluate the outcome of combined tibialis anterior tendon shortening (TATS) and calf muscle-tendon lengthening (CMTL) in spastic equinus. Prospectively collected data was analysed in 26 patients with hemiplegic (n=13) and diplegic (n=13) cerebral palsy (CP) (GMFCS level I or II, 14 males, 12 females, age range 10-35 years; mean 16.8 years). All patients had pre-operative 3D gait analysis and a further analysis at a mean of 17.1 months (±5.6months) after surgery. None was lost to follow-up. Twenty-eight combined TATS and CMTL were undertaken and 19 patients had additional synchronous multilevel surgery. At follow-up 79% of patients had improved foot positioning at initial contact, whilst 68% reported improved fitting or reduced requirement of orthotic support. Statistically significant improvements were seen in the Movement Analysis Profile for ankle dorsi-/plantarflexion (4.15°, p=0.032), maximum ankle dorsiflexion during swing phase (11.68°, p<0.001), and Edinburgh Visual Gait Score (EVGS) (4.85, p=0.014). Diplegic patients had a greater improvement in the EVGS than hemiplegics (6.27 -vs- 2.21, p=0.024). The originators of combined TATS and CMTL showed that it improved foot positioning during gait. The present study has independently confirmed favourable outcomes in a similar patient population and added additional outcome measures, the EVGS, foot positioning at initial contact, and maximum ankle dorsiflexion during swing phase. Study limitations include short term follow-up in a heterogeneous population and that 19 patients had additional surgery. TATS combined with CMTL is a recommended option for spastic equinus in ambulatory patients with CP.

Using a goal attainment scale in the evaluation of outcomes in patients with diplegic cerebral palsy

A goal attainment scale (GAS) was used to evaluate outcomes of surgical and non-surgical interventions to improve gait in 45 children with diplegic cerebral palsy. Personal goals were recorded during pre-intervention gait analysis in two groups. Twenty children underwent orthopaedic surgery (Group 1) and 25 children received a non-operative intervention (Group 2). Children and/or their carers were contacted post-intervention by telephone to complete a GAS questionnaire, rating the achievement of goals on a 5-point scale. The goals were similar in both groups. The composite GAS was transformed into a standardised measure (T-score) for each patient. Both groups on average achieved their goals (mean T-score for Group 2 was 56.3, versus 47.1 for Group 1). The difference between these two means was significant (p=0.010). Additionally, 16 children had undergone a follow-up gait analysis during the study period, but the relationship between their Gait Profile Score and GAS was not statistically significant. Both surgical and non-surgical interventions enabled children to achieve their goals, although Group 1 reported higher achievements. The GAS reflects patient's/parent's/carer's aspirations and may be as relevant as post-intervention kinematic or kinetic outcomes.

The relationship between the Edinburgh Visual Gait Score, the Gait Profile Score and GMFCS levels I-III

OBJECTIVE

To determine the relationship between the Edinburgh Visual Gait Score (EVGS) and the Gait Profile Score (GPS).

METHOD

Three dimensional gait data and EVGS scores from 151 diplegic children (Gross Motor Function Classification System (GMFCS) levels I-III) were used for analysis.

RESULTS

The EVGS correlated strongly with GPS (r=0.816). There was a significant difference in both gait scores between each level of the GMFCS.

CONCLUSIONS

The strong correlation of GPS with EVGS implies that any advantages of using GPS can also be applied to centres without 3-dimensional gait analysis facilities if the EVGS is used.

Hip surveillance and management of the displaced hip in cerebral palsy

INTRODUCTION

This article provides an overview of the management of a displaced hip in children with cerebral palsy and considers surveillance programmes, principles of surgical reconstruction and options for the salvage of an unreconstructable hip in these children.

CONCLUSION

Hip dislocation in CP is potentially preventable if children are included from an early age in a surveillance programme that includes repeat radiographic and clinical examinations, and preventive treatment for hips that are displacing. A surveillance programme should be based on the child's age, GMFCS level and migration percentage (MP), and surgical prevention may be considered in children with a MP exceeding 33 %.

Pathological femoral fracture caused by primary bone tumour: a population-based study

This population-based study aimed to analyse the demographic, clinical and histological features of patients with a malignant primary bone tumour of the femur presenting with a pathological fracture. Eighty-four patients were identified from a prospectively gathered national tumour database between 1960 and 2004. Demographic data, presenting features, tumour location, histological diagnosis, treatment, local recurrence, metastasis and survival data were gathered. An estimate of the annual incidence was obtained using population data from the General Register Office and was 0.4 per million population per annum. The mean age was 56 years (range 4-87 years) with a bimodal distribution and 46% were men or boys. Forty-one percent of patients presented with a history of trauma. The average duration of symptoms before presentation was 1-3 months. The most common histological diagnoses were osteosarcoma (14 patients) and Paget's sarcoma (12 patients). The local recurrence rate was 38% and the overall five-year survival was 22%. The prognosis was made worse by local tumour recurrence, the development of metastasis and age at diagnosis greater than 21 years. Limb salvage surgery did not alter the prognosis. Patients who present with pathological fracture of a primary malignant bone tumour, carry a poor prognosis in all tumour types and no improvement in survival was identified over the period of the study.

Natural history of flexed knee gait in diplegic cerebral palsy evaluated by gait analysis in children who have not had surgery

Eighteen children with diplegic cerebral palsy and no history of orthopaedic surgery had two gait analyses a mean of 6.3 years apart to analyse the effects of time on their gait. The mean age of the children at first analysis was 7.7 years (range 4.4-13.3 years). The data was analysed as a whole group (18 children) and as two sub-groups of nine children: those with a shorter follow-up (mean 5.0 years) and those with a longer follow-up (mean 7.5 years) between analyses. The following significant bilateral changes were seen in the whole group and longer follow-up sub-group: deterioration in the range of knee flexion, mid-stance knee flexion, peak knee extension in stance and hamstring length and an improvement in mean and maximum hip rotation. Temporal data showed no significant changes once normalised. There were no bilateral significant changes in data from children evaluated at a mean of 5 years follow-up. GMFCS scores generally improved over time despite the significant increase in flexed knee gait. There was no significant change in gait deviation index in any group over time. There was an increase in body mass index in 16 children but there was no correlation between this and the degree of mid-stance knee flexion. These findings may have implications for longer term follow-up of children with cerebral palsy into adulthood.

The pink, pulseless hand after supracondylar fracture of the humerus in children

This annotation discusses the findings of two papers in the current issue describing the management of the neurovascular complications of supracondylar fractures of the humerus in childhood, with particular reference to the indications for and the timing of exploration of the brachial artery and the affected nerves.

Reliability and validity of the Visual Gait Assessment Scale for children with hemiplegic cerebral palsy when used by experienced and inexperienced observers

This study investigated the reliability and validity of the Visual Gait Assessment Scale when used by experienced and inexperienced observers. Four experienced and six inexperienced observers viewed videotaped footage of four children with hemiplegic cerebral palsy on two separate occasions. Validity of the Scale was obtained by comparison with three-dimensional gait analysis (3DGA). The experienced observers generally had higher inter-observer and intra-observer reliability than the inexperienced observers. Both groups showed higher agreement for assessments made at the ankle and foot than at the knee and hip. The experienced observers had slightly higher agreement with 3DGA than the inexperienced observers. The inexperienced observers showed a learning effect and had higher inter-observer agreement and higher agreement with 3DGA in the second assessment of the videotapes. This scale can be used by inexperienced observers but is limited to observations in the sagittal plane and by poor reliability at the knee and hip for experienced and inexperienced observers.

The effect of simulated hamstring shortening on gait in normal subjects

The purpose of this study was to determine the effect of simulated hamstring shortening on gait in normal subjects. Six normal subjects wore an adjustable brace to simulate three different hamstring lengths. Evaluation of the physiological cost index (PCI) and gait analysis revealed that simulated hamstring shortening produced adverse affects in the gait of normal subjects. Significant effects were only observed when the popliteal angle exceeded 85 degrees (p<0.001) and included increased effort of walking (PCI), decreased speed, stride and step length; decreased hip flexion and increased knee flexion in stance, increased posterior pelvic tilt, decreased pelvic obliquity and rotation and premature ankle dorsi- and plantar-flexion in stance. These results emphasise the need to consider the effects of changing the length of the hamstrings on joints other than the hip and knee when assessing patients for hamstring lengthening.

The Footprint method to assess transmalleolar axis

Torsional deformities of the lower extremities are a common reason for an orthopaedic consultation and are also part of the evaluation of a patient in gait analysis. This study assessed the level of agreement between, and the repeatability of, the Footprint method and two other methods (Prone and Jig) of measuring the transmalleolar axis (TMA) clinically. The Footprint method measures the TMA as the patient sits by projecting the position of the malleoli downwards onto lined paper while the lines of the paper are aligned with the knee axis. The Prone method projects the position of the malleoli upwards onto the sole of the foot and this is related to the visually estimated knee axis. The Jig method uses a tropometer to relate the angle between the tibial tubercle and the two malleoli. Two assessors measured twelve subjects using the three methods and six subjects were re-measured approximately 1 week later for repeatability. There was poor agreement between the three methods but the Footprint method was the most repeatable (coefficient of repeatability: 5.4). One observer then assessed the repeatability of the effect of simulated equinus on the Footprint method in 10 normal subjects on 2 separate occasions 1 week apart. Equinus was obtained by having the subjects sit and firstly extend their knee and place the foot on the floor and secondly by placing the foot under consideration on a wedge. Both conditions introduced an offset into the measurement of the TMA when compared to the measurements with the ankle at neutral in the same subjects. The reliability of the Footprint method was then assessed using 10 inexperienced observers who measured nine normal subjects each on 2 separate occasions and their results compared with those from an experienced observer. The inexperienced observers were less repeatable than an experienced observer (coefficients of repeatability 9.2 and 6.9, respectively). We recommend that different methods of measuring TMA should not be used interchangeably in clinical practice. The Footprint method was the most repeatable of the three methods tested and can be used for patients who have fixed equinus but the measurement was less repeatable when used by inexperienced observers.

The conjoint junction of the triceps surae: Implications for gastrocnemius tendon lengthening

Forty embalmed cadaver lower limbs were dissected to identify the morphology of the conjoint junction of the tendons of gastrocnemius and soleus and the location of the gastrocnemius tendon relative to bony landmarks. Five patterns of conjoint junction morphology were found: transverse (25%), oblique passing distally and medially (45%), oblique passing distally and laterally (5%) and arcuate as an inverted U (17.5%) and a U-shape (7.5%). Left-right asymmetry of the junction was observed in 31.6% of 19 paired cadaver legs. On the medial side of the calf the gastrocnemius tendon could be located between 38 and 46% of the proportion of the distance between the upper border of the calcaneus and the fibular head. Corresponding values for the midline and lateral side of the calf were 45-58% and 48-51%. The location of the gastrocnemius tendon relative to bony landmarks may help to guide incision planning for open or endoscopic division of the tendon.

A Dega-type osteotomy after closure of the triradiate cartilage in non-walking patients with severe cerebral palsy

A total of 47 non-walking patients (52 hips) with severe cerebral palsy and with a mean age of 14 years, (9 to 27) underwent a Dega-type pelvic osteotomy after closure of the triradiate cartilage, together with a derotation varus-shortening femoral osteotomy and soft-tissue correction for hip displacement which caused pain and/or difficulties in sitting. The mean follow-up was 48 months (12 to 153). The migration percentage improved from a pre-operative mean of 70% (26% to 100%) to 10% (0% to 100%) post-operatively. In five hips the post-operative migration percentage was greater than 25%, which was associated with continuing pain in two patients. Three patients had persistent hip pain and a migration percentage less than 25%. In five hips a fracture through the acetabulum occurred, and in another there was avascular necrosis of the superior acetabular segment, but these had no adverse effect on functional outcome. We conclude that it is possible to perform a satisfactory pelvic osteotomy of this type in these patients after the triradiate cartilage has been closed.

Regression analysis of gait parameters with speed in normal children walking at self-selected speeds

Dimensionless analysis ensures that differences in sizes (e.g. height and weight) of children have a minimal influence on gait parameters. The results of changes in speed on gait parameters were examined using dimensionless analysis on data from a prospective 5-year study of 16 children. Linear regression analysis of peak and trough values of temporal distance parameters, ground reaction forces, joint angles, moments and powers provide a quantitative description of gait development with normalised speed. These linear relationships can be used to estimate gait parameters from speed measurements for normal subjects. However, caution is advised in using the data to attempt to predict an individual's gait parameters due to the wide spread of data about the regression lines and we do not recommend that the data be used to extrapolate the regression data to wider speed ranges.

Delay increases the need for open reduction of type-III supracondylar fractures of the humerus

Recent reports have suggested that a delay in the management of type-III supracondylar fractures of the humerus does not affect the outcome. In this retrospective study we examined whether the timing of surgery affected peri-operative complications, or the need for open reduction. There were 171 children with a closed type-III supracondylar fracture of the humerus and no vascular compromise in our study. They were divided into two groups: those treated less than eight hours from presentation to the Accident and Emergency Department (126 children), and those treated more than eight hours from presentation (45 children). There were no differences in the rate of complications between the groups, but children waiting more than eight hours for reduction were more likely to undergo an open reduction (33.3% vs 11.2%, p < 0.05) and there was a weak correlation (p = 0.062) between delay in surgery and length of operating time. Consequently, we would still recommend treating these injuries at the earliest opportunity.

Effects of methotrexate on human bone cell responses to mechanical stimulation

OBJECTIVES

Methotrexate (MTX), which is prescribed in the treatment of malignancy and autoimmune disease, has detrimental effects on a number of organ systems, including bone. At present, the exact mechanism of action of MTX on bone at the cellular level is unclear. Mechanical stimuli imparted by stretch, pressure, fluid flow and shear stress result in a variety of biochemical responses that are important in bone metabolism. Cyclical mechanical stimulation at 0.33 Hz induces rapid cell membrane hyperpolarization of human bone cells (HBC) via an integrin-mediated pathway which includes an IL-1beta autocrine/paracrine loop. This study was undertaken to investigate the effect of MTX on responses of HBC to 0.33 Hz mechanical stimulation.

METHODS

Electrophysiological responses of HBC were measured before and after mechanical stimulation at 0.33 Hz in the presence or absence of MTX. Semiquantitative RT-PCR was used to investigate effects of MTX on relative levels of type-1 collagen and bone morphogenetic protein-4 (BMP-4) following 0.33 Hz mechanical stimulation.

RESULTS

MTX dose-dependently inhibited HBC hyperpolarization in response to 0.33 Hz mechanical stimulation. Production/release of IL-1beta was inhibited by MTX, whereas its effects on target cells were not. Mechanical stimulation of HBC at 0.33 Hz caused a significant decrease in relative levels of BMP-4 mRNA, whereas relative levels of type-1 collagen mRNA were consistently increased, although these increases did not reach statistical significance. These trends were unaffected by MTX.

CONCLUSIONS

These studies show that MTX affects HBC mechanotransduction by interfering with integrin-mediated signalling. The data also suggest that the mechanotransduction pathway responsible for the regulation of type-1 collagen and BMP-4 gene expression may be distinct from the IL-1beta-mediated signalling pathway.

Electrical stimulation of gluteus maximus in children with cerebral palsy: effects on gait characteristics and muscle strength

The purpose of this study was to determine whether electrical stimulation of the gluteus maximus would improve hip extensor strength, decrease excessive passive and dynamic internal hip rotation, and improve gross motor function in children with cerebral palsy (CP). Twenty-two ambulant children (15 females, 7 males, mean age 8 years 6 months, SD 2 years 9 months, aged 5 to 14 years) with diplegic (n = 14), hemiplegic (n = 7), and quadriplegic (n = 1) CP participated in this study. All were randomly assigned to either the stimulation or control group. The stimulation group (n = 11) received electrical stimulation of the gluteus maximus of the most affected legs for 1 hour a day, 6 days a week for a period of 8 weeks. Electrodes were applied proximally and distally over the gluteus maximus, with the active electrode initially positioned over the motor points. The control group (n = 11) did not receive any extra treatment. Measurements of hip extensor strength, gait analysis, passive limits of hip rotation, and section E of the Gross Motor Function Measure were made before and after treatment for both groups. Subjectively, 7 of the 11 parents thought that the treatment made a difference to their child. However, no statistically or clinically significant improvement was found in the stimulation group when compared with the control group.

Normalisation of gait data in children

The comparative effect of semi-dimensional (SD) and non-dimensional (ND) normalisation on the results of a longitudinal study of gait in 5-12-year old children was investigated. The use of both height and leg length in the normalisation was examined. Only ND analysis could be used to identify subjects with the same accelerations. ND analysis of the children's gait indicated that there was little change in the combination of step length and cadence used to achieve a particular velocity between 5 and 12. The first peak and mid-stance trough values of the vertical component of ground reaction force did not change with age. We recommend the use of ND normalisation rather that SD to allow comparisons between individuals of differing size and mass.

Management of completely displaced metaphyseal fractures of the distal radius in children. A prospective, randomised controlled trial

In a prospective, randomised controlled trial, 68 children who had a completely displaced metaphyseal fracture of the distal radius were treated either by manipulation (MUA) and application of an above-elbow cast alone or by the additional insertion of a percutaneous Kirschner (K-) wire. Full radiological follow-up to union was obtained in 65 children and 56 returned for clinical evaluation three months after injury. Maintenance of reduction was significantly better in the K-wire group and fewer follow-up radiographs were required. There was no significant difference in the clinical outcome measured three months after injury. Seven of 33 patients in the MUA group had to undergo a second procedure because of an unacceptable position compared with none of the 35 in the K-wire group (chi-squared test, p < 0.01). One patient in the K-wire group required exploration for recovery of a migrated wire. We conclude that the use of a percutaneous K-wire to augment the reduction of the fracture in children who have a completely displaced metaphyseal fracture of the distal radius is a safe and reliable way of maintaining alignment of the fracture.

Management of completely displaced metaphyseal fractures of the distal radius in children

In a prospective, randomised controlled trial, 68 children who had a completely displaced metaphyseal fracture of the distal radius were treated either by manipulation (MUA) and application of an above-elbow cast alone or by the additional insertion of a percutaneous Kirschner (K-) wire. Full radiological follow-up to union was obtained in 65 children and 56 returned for clinical evaluation three months after injury.

Maintenance of reduction was significantly better in the K-wire group and fewer follow-up radiographs were required. There was no significant difference in the clinical outcome measured three months after injury. Seven of 33 patients in the MUA group had to undergo a second procedure because of an unacceptable position compared with none of the 35 in the K-wire group (chi-squared test, p < 0.01). One patient in the K-wire group required exploration for recovery of a migrated wire.

We conclude that the use of a percutaneous K-wire to augment the reduction of the fracture in children who have a completely displaced metaphyseal fracture of the distal radius is a safe and reliable way of maintaining alignment of the fracture.

Sagittal joint kinematics, moments, and powers are predominantly characterized by speed of progression, not age, in normal children

Twenty-six healthy 7-year-old children were enrolled in a 5-year longitudinal study to examine the importance of age and speed in the characterization of sagittal joint angles, moments, and powers. In 740 gait trials, children walking at self-selected speeds were examined on the basis of age and normalized speed [speed/(height x g)1/2]. The kinematics and kinetics in these children were characterized predominantly by normalized speed of progression and not age. The clinical relevance of these findings is that normalized speed of walking, rather than age, should be considered when comparing normal with pathologic gait.

Normalized speed, not age, characterizes ground reaction force patterns in 5-to 12-year-old children walking at self-selected speeds

Twenty-six healthy 5-year-old children were enrolled in a 7-year longitudinal study to examine the importance of age and speed in the characterization of ground reaction forces. One thousand forty gait trials of children walking at self-selected speeds were examined on the basis of age and normalized speed [speed/(height x g)(1/2)]. Results, presented as discrete peak and trough values and as continuous trace plots over the stance phase, indicated that there was little change in ground reaction forces with age, but there were significant changes in vertical force and anterior-posterior force values with normalized speed. The ground reaction force patterns in these children were characterized predominantly by normalized speed of progression and not age. The clinical relevance of these findings is that normalized speed of walking, rather than age, should be considered when comparing normal with pathological gait.

Human bone cell hyperpolarization response to cyclical mechanical strain is mediated by an interleukin-1beta autocrine/paracrine loop

Mechanical stimuli imparted by stretch, pressure, tension, fluid flow, and shear stress result in a variety of biochemical responses important in bone (re)modeling. The molecules involved in the recognition and transduction of mechanical stimuli that lead to modulation of bone cell function are not yet fully characterized. Cyclical pressure-induced strain (PIS) induces a rapid change in membrane potential of human bone cells (HBC) because of opening of membrane ion channels. This response is mediated via integrins and requires tyrosine kinase activity and an intact actin cytoskeleton. We have used this electrophysiological response to further study the signaling events occurring early after mechanical stimulation of HBC. Stimulation of HBC at 0.33 Hz PIS, but not 0.104 Hz PIS, results in the production of a transferable factor that induces membrane hyperpolarization of unstimulated HBC. The production of this factor is inhibited by antibodies to beta1-integrin. Interleukin-1beta (IL-1beta and prostaglandin E2 (PGE2) were identified as candidate molecules for the transferable factor as both were shown to induce HBC hyperpolarization by opening of small conductance calcium-activated potassium channels, the means by which 0.33 Hz PIS causes HBC hyperpolarization. Antibodies to IL-1beta, but not other cytokines studied, inhibit the hyperpolarization response of HBC to 0.33 Hz PIS. Comparison of the signaling pathways required for 0.33 Hz PIS and IL-1beta-induced membrane hyperpolarization shows that both involve the phospholipase C/inositol triphosphate pathway, protein kinase C (PKC), and prostaglandin synthesis. Unlike 0.33 Hz PIS-induced membrane hyperpolarization, IL-1beta-induced hyperpolarization does not require tyrosine kinase activity or an intact actin cytoskeleton. These studies suggest that 0.33 Hz PIS of HBC induces a rapid, integrin-mediated, release of IL-1beta with a subsequent autocrine/paracrine loop resulting in membrane hyperpolarization. IL-1beta production in response to mechanical stimuli is potentially of importance in regulation of bone (re)modeling.

A comparison of hip guidance with reciprocating gait orthoses in children with spinal paraplegia: results of a ten-year prospective study

Twenty-two children with spinal paraplegia were entered into a prospective randomised study to assess the efficacy of two reciprocating orthoses and to identify any prognostic factors that might affect continuing use of the devices. Thirteen received a hip guidance orthosis (HGO) and nine a reciprocating gait orthosis (RGO). They were followed for a mean of ten years. At one year follow-up there were three statistically significant differences between the two groups at the 5% level: repairs were commoner in the RGO group, the RGO group improved in their ability to walk over difficult outdoor surfaces and the HGO group improved more in their ability to rise from a sitting to standing position. At one year follow-up there was a positive parental and child's view of the benefits of the orthoses, but by ten years only 24% of the patients were still using the orthoses. We were not able to show any definite advantage of one device over the other or any statistically significant prognostic factors for walking in the longer term with a reciprocating orthosis. We question whether or not the routine provision of these types of orthosis is justifiable when it appears that, in the longer term, the patients we studied preferred wheelchair mobility.

Extension of the elbow and supracondylar fractures in children

We tested the hypothesis that children who sustain a supracondylar fracture have a greater range of elbow hyperextension than those with a fracture of the distal radius. Three observers made 358 measurements in 183 children (114 boys and 69 girls). There were 119 fractures of the distal radius and 64 supracondylar fractures. Initially, the group with a supracondylar fracture appeared to have extension 1.7 degrees greater than that of the group with fracture of the distal radius. On average, there was a maximum variation of 3 degrees between observers. After allowing for age, gender and observer, there was no significant difference between the groups. Our study had greater than 80% power to detect a difference in hyperextension of 2 degrees at the 5% level with the above observer variability. When age and gender are taken into account, any variation in the amount of hyperextension at the elbow is not sufficient to explain the occurrence of a supracondylar fracture.

Can transverse plane rotations be estimated from video tape gait analysis?

The use of video tape in gait analysis is widespread and is frequently used when more sophisticated 3-dimensional analysis systems are not available or cannot be used. Its major shortcoming however is that it does not readily yield information about rotations in the transverse plane which may be amongst the most diagnostically significant features of pathological gait. This paper describes an inexpensive device which may be used, in conjunction with video taping, to aid visual estimation of transverse plane rotations, and quantifies the accuracy with which this was done by experienced observers. Copyright 1998 Elsevier Science B.V.

Synovial presentation of non-Hodgkin's lymphoma

The MRI appearances of synovial involvement from non-Hodgkin's lymphoma are described in a 61-year-old man. These appearances have not previously been described and the differential diagnosis is discussed.

Electrophysiological responses of human bone cells to mechanical stimulation: evidence for specific integrin function in mechanotransduction

Bone cells respond to mechanical stimuli, but the transduction mechanisms responsible are not fully understood. Integrins, a family of heterodimeric transmembrane glycoproteins, which link components of the extracellular matrix with the actin cytoskeleton, have been implicated as mechanoreceptors. We have assessed the roles of integrins in the transduction of cyclical mechanical stimuli to human bone cells (HBCs), which results in changes in membrane potential. HBC showed membrane depolarization following 0.104 Hz mechanical stimulation and membrane hyperpolarization following stimulation at 0.33 Hz. The membrane depolarization response involved tetrodotoxin-sensitive sodium channels and could be inhibited by antibodies against alpha V, beta 1, and beta 5 integrins. In contrast, the hyperpolarization response was inhibited by gadolinium and antibodies to the integrin-associated protein (CD47), alpha 5 and beta 1 integrin. Both responses could be abrogated by ARg-Gly-Asp (RGD)-containing peptides, inhibition of tyrosine kinase activity, and disruption of the cytoskeleton. These results demonstrate differential electrophysiological responses of HBC to different frequencies of mechanical strain. Furthermore, they suggest that integrins act as HBC mechanoreceptors with distinct signaling pathways being activated by different frequencies of mechanical stimuli.

Inaccuracy of the migration percentage and center-edge angle in predicting femoral head displacement in cerebral palsy

Six patients (seven hips) with total-body-involvement cerebral palsy were assessed for a hip reconstruction. Four patients (five hips) underwent three-dimensional computerized tomographic (3D CT) scans, and in two patients, faux profile views were obtained. The femoral head was subluxed or dislocated anteriorly in all seven hips. The migration percentage (MP) and center-edge angle (CEA) underestimated the pathology. We conclude that the MP and CEA do not exclude an anterior displacement of the femoral head and calls into question the accuracy of methods relying on two-dimensional imaging in assessing hip containment in this group of patients. The faux profile view is sufficient to show an anterior hip displacement but a 3D CT gives superior detail to help in planning a surgical reconstruction.

Gait patterns in children with hemiplegic spastic cerebral palsy

Twenty-six nonoperated spastic hemiplegic children underwent three-dimensional kinetic gait analysis. We identified five patterns based on sagittal plane kinetics. Group I had a minimal gait disturbance, a drop foot pattern, and normal kinetics, Group II had a flexed knee but normal hip extension, Group III a flexed knee and hip, Group IV knee hyperextension and tibial arrest, and Group V knee hyperextension and persistent ankle dorsiflexion. We concluded that Group I had weak anterior tibial muscles, and in stance Group II a functionally tight gastrocnemius, Group III a functionally tight gastrocnemius and hip flexors, and Group IV a functionally tight soleus, and in Group V the patients generated an abnormally large fore-aft shear force and the gastrocnemius and soleus were not tight. Kinetics help in the understanding of gait aberrations in spastic hemiplegia.

The value of internal fixation and radiotherapy in the management of upper and lower limb bone metastases

Fifty-four consecutive patients underwent 61 orthopaedic operations for metastatic bone disease affecting the upper and lower limbs. These patients were subsequently managed using a consistent postoperative radiotherapy (RT) policy. There were 27 prophylactic internal fixations and 34 internal fixations of pathological fractures. There was a marked difference in survival between these groups. The median postoperative survival of the prophylactic (P) group was 15 months whereas that of the fracture (F) group was 2 months (P less than 0.0001). Ninety-three per cent of the P group and 59% of the F group were able to be discharged home following treatment. Subsequent local fracture requiring further surgical intervention occurred in 11% of the P group and in none of the F group. Seventy-eight per cent of the P group and 62% of the F group did not suffer any further sequelae at the operation site until the time of death or last follow-up. Patient mobility following surgery and RT for metastatic lesions occurring in the lower limb was significantly improved in both the P group (P less than 0.05) and in the F group (P less than 0.0001) such that 91% and 58%, respectively, of these patients were subsequently able to walk.

Ankle-foot orthosis function in low-level myelomeningocele

Six children with low-level myelomeningocele underwent gait analysis. All showed excessive ankle dorsiflexion and knee flexion when walking barefoot. A rigid thermoplastic ankle-foot orthosis (AFO) improved gait by preventing ankle dorsiflexion and reducing knee flexion. Biomechanically, the AFO caused a reduction in external knee moment by aligning the knee with the ground reaction force. Small changes in the foot-shank angle of the orthosis had profound effects on knee mechanics. Knee hyperextension could be controlled by a rocker sole. Kinetic gait analysis permits understanding of the biomechanical effects of orthoses.

Reliability of the acetabular teardrop as a landmark

This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.

Double dislocations of digits

We report eight patients who sustained simultaneous dislocations of two joints in a digit. The little finger was involved in five patients.

Biomechanical effects of rockers on walking in a plaster cast

Rockers are applied to lower limb casts to assist walking but there is little information on their biomechanical effects. The performances of 10 commercially available rockers were compared. They were applied to a below-knee cast worn by a normal subject who was also tested walking in the cast alone. Gait analysis was used to evaluate kinematic and kinetic data. The design of rocker had no effect upon the kinematics of walking. However, using new criteria for kinetic assessment of rocker function (tibial floor angular velocity and centre of pressure progression), most designs had a deleterious effect on the biomechanics of gait. Only two rockers approached the ideal kinetic criteria.

Treatment of congenital pseudarthrosis of the tibia by the Ilizarov method

Three cases of congenital pseudarthrosis were treated by the Ilizarov method. Consolidation was obtained by 3.5 months in three patients who had undergone several previous surgical procedures. Although the length of follow-up was short (maximum 3.5 years), consolidation occurred more quickly than by traditional methods. This technique also permitted both simultaneous correction of axial malalignment and leg lengthening. We think that this method has a place as a salvage procedure except where the distal fragment is very thin or dystrophic.

The isoelastic hip prosthesis followed for 5 years

In 1981 and 1982, 58 patients (61 hips) received an isoelastic noncemented femoral component and a bipolar cup for nontraumatic hip disease. Three patients were lost to follow-up and 8 died, leaving 47 patients (51 hips) for review after a minimum of 5 years. There were seven failures--two infections, four technical errors, and one migration of an acetabular component. Of the remaining 44 hips, 42 scored good or better at review.

Hard labour: injury to wife and husband during forceps delivery

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Bilateral Salter-Harris type II upper tibial epiphyseal fractures

We present a case of bilateral Salter-Harris type II epiphyseal injury to the proximal tibial epiphysis that occurred during gentle exercise. The mechanism and the likely contribution of preexisting Osgood-Schlatter disease are discussed.

Is elective surgery in the elderly worthwhile?

In a prospective study 102 patients (median age 70.9 years) were interviewed at home before and after elective surgery to assess whether they would have any difficulties in managing their activities of daily living (ADL) post-operatively. The patients were consecutive admissions in general surgery, gynaecology and urology. All patients were alive six months after surgery and 98 were cured of their condition. Twelve patients suffered a deterioration in their ability to perform various ADLs but none was institutionalised as additional help was given either by a spouse or by a home help. Elective surgery in this age group is worthwhile and carries with it minimal deleterious effects on social rehabilitation and few demands on community resources.

An unusual case of torticollis

A case is presented of a 9-year-old boy who developed torticollis caused by fibrosis at the site of a former ventriculoperitoneal shunt.

Normal electroencephalograms in idiopathic scoliosis

Twenty-five children with idiopathic scoliosis and without known neurologic disease and 25 age- and sex-matched controls had a standard electroencephalogram (EEG) performed and scrutinised blind. The EEGs were normal in the 25 children with idiopathic scoliosis and 24 controls were normal. Our study does not support the view that idiopathic scoliosis has a central neurologic cause.

Primary acute haematogenous osteomyelitis of an isolated metatarsal in children

Acute haematogenous osteomyelitis of an isolated metatarsal is a rare condition in childhood. Fourteen children diagnosed with this condition were followed up for an average of 3 years. Organisms responsible were found to be either Staphylococcus aureus or Streptococcus pyogenes. Growth disturbances of the metatarsal were seen in the majority, but the radiographic features were not serious in the long term, and no child was subsequently disabled. Since these children often present with symptoms akin to trauma, a better recognition of the condition is required to avoid misdiagnosis.

The results of surgery for nail dystrophy of the hallux in children

The efficacy of surgery for nail dystrophy of the hallux has been evaluated in 52 children studied retrospectively. 69 primary procedures were carried out with an overall symptomatic recurrence rate of 40%. When used as a primary procedure, avulsion alone had a symptomatic recurrence rate of 54% and Zadik 's procedure 29%. When avulsion was repeated, the recurrence rate rose to 100%. Avulsion alone cannot be recommended, but if surgery is contemplated Zadik 's procedure is the most effective.

Phenol cauterization in the management of ingrowing toenails

Phenol cauterization has been carried out on 150 toes in 121 patients with an ingrowing toenail. There was no significant morbidity and the procedure was tolerated well by all patients. Overall recurrence rate was found to be 4 per cent after nine months. This figure compares favourably with surgical ablation techniques and when combined with improved patient tolerance indicates that phenol cauterisation may be the ablation procedure of choice in the treatment of an ingrowing toenail.

Surgical treatment of ingrowing toenails in infancy and childhood

76 patients were reviewed retrospectively to assess the efficacy of surgery for ingrowing toenails. 110 primary procedures were carried out with an overall symptomatic recurrence rate of 415. When used as a primary procedure, avulsion alone has a symptomatic recurrence rate of 45%, wedge excision 33% and Zadik's procedure 16%. A nail-bed ablation is the most effective treatment for ingrowing toenails.