Identification of complications in paediatric cerebral palsy treated with intrathecal baclofen pump: a descriptive analysis of 15 years at one institution

PURPOSE

Intrathecal baclofen (ITB) treatment is used with increasing frequency in the cerebral palsy population. We describe the complications of ITB treatment, the incidence of complications, and our experience with their treatment.

METHODS

In a period of 15 years, 341 paediatric patients with cerebral palsy treated with ITB were evaluated. Device problems associated with the catheter or pump, or infection and complications such as cerebrospinal fluid (CSF) leak and postdural spinal headache, were reviewed. Infection was classified as early (≤ 90 days) or late (> 90 days) according to the time of onset.

RESULTS

The infection rate was 6.9% per procedure (50/720) and 14.6% per patient (50/341) over a mean 6.3 ± 3.9 years. There was a positive correlation between the risk of infection and preoperative comorbidities including epilepsy/seizure history, feeding tube, and mixed type cerebral palsy (p < 0.05, p = 0.03, p = 0.01, respectively). Eighty-five (24.9%) patients experienced 90 CSF leak episodes; 61 of these 85 patients had headache complaints as a result of CSF leak. There was a positive correlation between the risk of early infection and CSF leak (p < 0.05).

CONCLUSIONS

The most common complication related to ITB was associated with pump and catheter problems. The rate of complications with the use of ITB is relatively high; however, based on the literature reports, it is the most effective treatment for severe spasticity and dystonia in patients with severe cerebral palsy.

LEVEL OF EVIDENCE

III.

Management practices associated with strongylid parasite prevalence on horse farms in rural counties of Kentucky

Anthelmintic resistance among cyathostomin parasites is a wide-spread problem. The parasite control guidelines written by the American Association of Equine Practitioners (AAEP) encourages the preservation of anthelmintic efficacy by reducing treatment frequency, using targeted deworming, and implementing environmental management practices. While there is knowledge regarding parasite management practices of affluent horse farms in the United States, surveys rarely explore the rural and underserved regions. The purpose of this study was to observe the management practices of horse farms in rural regions Kentucky, including working Amish farms, and determine factors associated with strongyle prevalence. A total of 160 horses among 38 owners from 28 different farms were enrolled in this study. A questionnaire survey regarding equine information, farm management, and deworming history was performed with each owner. Fecal samples were collected to determine fecal egg counts, perform coprocultures for subsequent strongyle larvae identification, and Strongylus vulgaris specific PCR. Serum samples were collected for the S. vulgaris antibody specific ELISA. The mean number of deworming treatments given in the last year was 2.1 with a 95% confidence interval of 1.9-2.3 with ivermectin being the most common active used. Statistical analysis showed horses treated within the last three months with a macrocylic lactone (ML) drug had significantly lower egg counts than horses treated with a ML 7-9 months ago (p = .0005). Despite the AAEP recommendations to reduce the overall number of treatments by using a surveillance-based approach and to no longer rotate treatments, only 17 horses reportedly had a fecal sample submitted for a fecal egg count and 65 horses were dewormed in a rotational manner. Horses whose owners utilized an informative deworming source (i.e., veterinarian, internet, magazine, local feed store) also had significantly lower counts (p = .0026). All coprocultures were negative for S. vulgaris while five horses were PCR positive. Interestingly, 95 horses tested ELISA positive for S. vulgaris. The strongyle egg counts of the working Amish horses were not significantly different from the other horses in this study and deworming practices including the use of efficacious drugs and low treatment frequencies were in accordance with the AAEP guidelines. This study was the first to summarize deworming management practices of rural regions in Kentucky, including a working Amish community. Overall, horse owners employed deworming practices recommended by the AAEP, however rotational deworming is still commonly implemented and fecal egg counts are rarely used.

Prophylactic antibiotics in soft-tissue procedures in children with cerebral palsy

PURPOSE

Data on the benefits of perioperative prophylactic antibiotics in the paediatric population are lacking. In this study, we aimed to assess the rate of infection after isolated soft-tissue procedures in patients with cerebral palsy with and without preoperative prophylactic antibiotics between 2009 and 2015.

METHODS

We reviewed the records of all children with cerebral palsy who underwent isolated soft-tissue procedures (on the upper and lower limb) at our hospital between 2009 and 2015. Children with at least 30-day postoperative follow-up were included. Children who had groin incisions were excluded.

RESULTS

Two groups were identified: the antibiotic group (77 children with 203 incisions and 343 procedures) had one surgical site infection; the no-antibiotic group (48 children with 102 incisions and 177 procedures) had no surgical site infections.

CONCLUSION

These results suggest that the use of preoperative antibiotics does not change the rate of postoperative surgical site infections.

LEVEL OF EVIDENCE

Level III therapeutic study.

Foot and ankle deformities in children with Down syndrome

PURPOSE

Foot and ankle deformities are common orthopaedic disorders in children with Down syndrome. However, radiographic measurements of the foot and ankle have not been previously reported. The aim of this study is to describe the foot and ankle deformity in children with Down syndrome.

METHODS

Children who had foot and ankle radiographs in the standing weight-bearing position were selected. Three groups of patients were identified. The relationship of radiographic measurements with age, body mass index and pain is discussed. In all, 41 children (79 feet) had foot radiographs and 60 children (117 ankles) had ankle radiographs, with 15 children overlapping between Groups I and II.

RESULTS

In Group I, hallux valgus deformity was seen before ten years of age and hallux valgus angle increased afterwards. Metatarsus adductus angle showed a significant increase (p = 0.006) with obesity and was higher in patients who had foot pain (p = 0.05). In Group II, none of the ankle measurements showed a significant difference with age or body mass index percentiles. Tibiotalar angle (TTA) and medial distal tibial angle (MDTA) were higher in patients who had ankle pain. In Group III, correlation analysis was performed between the different measurements with the strongest correlations found between TTA and MDTA.

CONCLUSION

In children with Down syndrome, radiographic evaluation of the foot and ankle reveals higher prevalence of deformities than clinical examination. However, foot and ankle radiographs are needed only for symptomatic children with pain and gait changes.

LEVEL OF EVIDENCE

Level IV - Prognostic Study.

Patient-reported mobility function and engagement in young adults with cerebral palsy: a cross-sectional sample

PURPOSE

To describe self-reported life satisfaction and motor function of young adults with cerebral palsy (CP).

METHODS

A total of 57 young adults with spastic CP classified as levels I (seven), II (25), III (16), IV (nine) by the Gross Motor Function Classification System, followed from childhood by our CP clinic, returned at a mean age of 27 years two months (SD 3 years 4 months). Self-reported life satisfaction and mobility status were measured by the Pediatric Outcomes Data Collection Instrument (PODCI), Patient-Reported Outcomes Measurement Information System (PROMIS), Functional Mobility Scale (FMS) and a project questionnaire. Surgical history and childhood mobility were confirmed from medical records.

RESULTS

The Functional Mobility Scale demonstrated limited but stable mobility function from childhood to adulthood. The PROMIS and PODCI revealed limited motor function compared with a non-disabled normative reference (p < 0.05). Descriptive results showed high dependence on transportation, housing and income; although PROMIS subscales revealed satisfaction with social activities. Self-recall of childhood mobility function using the FMS correlated highly (r = 0.8; p < 0.0001) with historical records.

CONCLUSION

Although functional mobility is limited and community independence is not fully achieved in young adults with CP, these participants maintained childhood levels of mobility function into young adulthood, were satisfied with social roles and had minimal reports of pain.

Flexed-knee gait in children with cerebral palsy

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.

Patients and Methods

A total of 59 young adults with spastic cerebral palsy, with a mean age of 26 years (sd 3), were enrolled into the study in which their gait was compared with an evaluation that had taken place a mean of 12 years (sd 2) previously. At their visits during adolescence, the children walked with excessive flexion of the knee at initial contact and surgical or therapeutic interventions were not controlled between visits.

Results

Based on the change in flexed-knee gait over approximately ten years, improvements were seen in increased Gait Deviation Index (p < 0.001) and decreased flexion of the knee at initial contact (p < 0.001). Greater popliteal angle (p < 0.001), reduced Gross Motor Function Measure section D (p = 0.006), and reduced speed of gait (p = 0.007) suggested a mild decline in function. Quality-of-life measures showed that these patients fell within normal limits compared with typical young adults in areas other than physical function.

Conclusion

While some small significant changes were noted, little clinically significant change was seen in function and gait, with gross motor function maintained between adolescence and young adulthood. Cite this article: Bone Joint J 2018;100-B:549–56.

Modeling the Recovery from Depressive Illness by an Exponential Model with Mixed Effects

In clinical trials of antidepressant treatments, a depression rating score is usually measured at several points of time for each patient. We propose an approach to fit data from this type of clinical trial using an exponential mixed-effects model. Compared to previous proposals, this approach has the advantage that individual recovery curves are fitted rather than curves of means. Furthermore, no artificial fixing of model parameters is needed as in other approaches. The flexibility of the proposed model is shown for various situations. The approach is illustrated by an example from a placebo-controlled study for the treatment of depression with St. John’s Wort (Hypericum perforatum).

Longitudinal change in foot posture in children with cerebral palsy

PURPOSE

Foot deformities are common in children with cerebral palsy (CP), yet the evolution of such deformities is not well documented. We aimed to observe and analyse changes in foot posture during growth in children with CP. Methods We followed 51 children (16 unilateral, 35 bilateral; 37 Gross Motor Function Classification Scale (GMFCS) I/II, 14 III/IV) aged two to 12 years in this level II, IRB-approved prospective longitudinal study. Data after bony foot corrections were excluded. Outcome measures included coronal plane pressure index (CPPI) and pressure impulses from the heel, medial midfoot and medial forefoot. Data were LOESS smoothed and resulting models were compared for significant differences across time using a derived FANOVA method.

RESULTS

The GMFCS I/II group had more foot valgus than typically developing (TD) children until seven years which normalised thereafter. From two to 12 years, GMFCS III/IV children had more foot valgus than TD children. Heel impulse was significantly reduced in both GMFCS groups compared with TD children, and the III/IV group had less heel contact than the I/II group.

CONCLUSIONS

Due to early variability and the tendency for resolving valgus foot posture in children with CP, conservative management of coronal plane foot deformity is suggested in early childhood, especially for children classified as GMFCS I and II.

Underdevelopment of trabecular bone microarchitecture in the distal femur of nonambulatory children with cerebral palsy becomes more pronounced with distance from the growth plate

SUMMARY

We found that the underdeveloped trabecular bone microarchitecture in the distal femur of children with cerebral palsy (CP) who are unable to ambulate independently becomes more pronounced with increased distance from the growth plate. This suggests that the degree of underdevelopment in trabecular bone in children with CP is greater than previously understood.

INTRODUCTION

Children with CP who are unable to ambulate independently have severely underdeveloped trabecular bone microarchitecture in the distal femur. The aim of the study was to determine if the level of underdevelopment in trabecular bone microarchitecture is consistent across the distal femur in children with CP.

METHODS

Children with quadriplegic CP and typically developing children were studied (n=12/group, 5-14 years). Apparent bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th), and trabecular separation (appTb.Sp) were estimated in each of 20 magnetic resonance images collected above the growth plate in the distal femur.

RESULTS

For the total region, appBV/TV, appTb.N, and appTb.Th were lower (30, 21, and 12%, respectively) and appTb.Sp was higher (52%) (all p≤0.001) in children with CP than in controls. Distance from the growth plate was inversely related to appBV/TV and appTb.N and was positively related to appTb.Sp at the same distance in children with CP and controls (all p<0.01). However, the relationships were stronger (r2=0.87 to 0.92 versus 0.36 to 0.65) and the slopes were steeper in children with CP (all p<0.01). Furthermore, the steepness of the slopes in children with CP was positively related to appBV/TV, appTb.N, appTb.Th, and appTb.Sp for the total region (r2=0.37 to 0.75, p<0.05).

CONCLUSIONS

The underdeveloped trabecular bone microarchitecture in the metaphysis of the distal femur in children with CP becomes more pronounced with greater distance from the growth plate. This pattern is most profound in children with the least developed trabecular bone microarchitecture.

[Variability in the implementation of health-promoting community activities in Spain]

BACKGROUND

To describe the variability in the application of community activities (CA) promoting health, in support received, in training, and in evaluation of the participation of professionals, administration and social partners in these.

METHODS

Survey to key informants identified in each region with the help of the Spanish Society of Family and Community Medicine. The questionnaire included a definition of a health promotion community activity. The study was conducted in 2008.

RESULTS

There was variability in community activities by region. The most involved professionals are nurses and social workers. Most of the regions (15 of 17) offer training in these issues to their professionals, especially in health education. It is less frequent to offer training to family medicine residents (10 of 17 regions) and to the different nursing specialties (6 of 17). The main institutional support comes from primary health care management, regional health services, municipalities, and public health services, and non-institutional support from scientific societies, civic associations and NGOs. On the evaluation of the involvement of different organizations and institutions in these activities, the only entities receiving pass grades were NGOs (3 out of 5) and primary health care (2.5 out of 5).

CONCLUSIONS

There is a high variability in the ways of supporting and promoting community activities in each region and consequently in their dissemination and implementation by primary health care teams. Nurses and social workers are key players in this process.

Energy cost of walking in children with spastic cerebral palsy: relationship with age, body composition and mobility capacity

The energy cost (EC) of walking is different for typically developing (TD) and children with cerebral palsy (CP). The associated factors of EC are not fully understood in children with CP. We assessed the relationship between EC and age, body surface area (BSA), and gross motor function measure (GMFM). We retrospectively examined data collected between 2003 and 2011 on 276 children aged 4-18 years who were classified as Gross Motor Function Classification System level I, n=79; II, n=123; and III, n=74. Energy cost was assessed while children walked 6-8 min at a comfortable, self-selected speed using their typical walking aids and/or orthoses as part of a clinical gait analysis. During the test, participants wore a breath-by-breath portable gas analysis system, measuring oxygen consumption. To calculate EC (J/kg/m), oxygen consumption was converted to J/kg/min and divided by walking speed. Data were analyzed using linear regression model. Energy cost correlated inversely with age (β=-0.16, R2=0.02, P=0.01), BSA (β=-3.35, R2=0.11, P<0.0001), and GMFM (β=-0.12, R2=0.42, P<0.0001). In the multiple linear regression model, GMFM was the most potent correlate of EC, BSA explained another 10% of the variance (R2=0.53), and age was a marginally significant correlate of EC (P=0.08). In summary, in children with CP in our study, EC decreased as GMFM and BSA increased, and GMFM was the most potent correlate of EC.

Psychometric evaluation of ADAS-Cog and NTB for measuring drug response

AIMS

To conduct a psychometric analysis to determine the adequacy of instruments that measure cognition in Alzheimer's disease trials.

BACKGROUND

Both the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog) and the Neuropsychological Test Battery (NTB) are validated outcome measures for clinical trials in Alzheimer's disease and are approved also for regulatory purposes. However, it is not clear how comparable they are in measuring cognitive function. In fact, many recent trials in Alzheimer's disease patients have failed and it has been questioned if ADAS-Cog still is a sensitive measure.

MATERIALS AND METHODS

The present paper examines the psychometric properties of ADAS-Cog and NTB, based on a post hoc analysis of data from a clinical trial (NCT01024660), which was conducted by AstraZeneca, in mild-to-moderate Alzheimer's disease (AD) patients, with a Mini Mental State Examination (MMSE) Total score 16-24. Acceptability, reliability, different types of validity and ability to detect change were assessed using relevant statistical methods. Total scores of both tests, as well as separate domains of both tests, including the Wechsler Memory Scale (WMS), Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency Condition, were analyzed.

RESULTS

Overall, NTB performed well, with acceptable reliability and ability to detect change, while ADAS-Cog had insufficient psychometric properties, including ceiling effects in 8 out of a total of 11 ADAS-Cog items in mild AD patients, as well as low test-retest reliability in some of the items.

DISCUSSION

Based on a direct comparison on the same patient sample, we see advantages of the NTB compared with the ADAS-Cog for the evaluation of cognitive function in the population of mild-to-moderate AD patients. The results suggest that not all of ADAS-Cog items are relevant for both mild and moderate AD population.

CONCLUSIONS

This validation study demonstrates satisfactory psychometric properties of the NTB, while ADAS-Cog was found to be psychometrically inadequate.

Long-term outcome of reconstruction of the hip in young children with cerebral palsy

We reviewed the long-term radiological outcome, complications and revision operations in 19 children with quadriplegic cerebral palsy and hip dysplasia who underwent combined peri-iliac osteotomy and femoral varus derotation osteotomy. They had a mean age of 7.5 years (1.6 to 10.9) and comprised 22 hip dislocations and subluxations. We also studied the outcome for the contralateral hip. At a mean follow-up of 11.7 years (10 to 15.1) the Melbourne cerebral palsy (CP) hip classification was grade 2 in 16 hips, grade 3 in five, and grade 5 in one. There were five complications seen in four hips (21%, four patients), including one dislocation, one subluxation, one coxa vara with adduction deformity, one subtrochanteric fracture and one infection. A recurrent soft-tissue contracture occurred in five hips and ten required revision surgery.

In pre-adolescent children with quadriplegic cerebral palsy good long-term outcomes can be achieved after reconstruction of the hip; regular follow-up is required.

Cite this article: Bone Joint J 2013;95-B:259–65.

Multipotent human breast stem cell line MCF1OAT

Human breast epithelial MCF10AT cells injected with Matrigel into the subcutis of nude/beige mice form simple ducts which, with time, resemble human proliferative breast disease and sporadically progress to carcinoma. Basement membrane was visualized with a silver stain and myoepithelial cells detected by their reactivity with antibody against smooth muscle actin. The ducts formed in situ are bilayered, composed of both myoepithelial and luminal epithelial layers circumscribed by a distinct basement membrane. The human origins of both luminal and myoepithelial layers were confirmed with fluorescent in situ hybridization with a probe for human chromosome 9. Electron microscopic studies reveal actin bundles and the formation of hemidesmosomes bordering the basement membrane, consistent with myoepithelium, as well as the formation of desmosomes between luminal and myoepithelial cells.

The structure of eosinophil leukocyte granules in rodents and in man

The structure of the specific granules of eosinophil leukocytes has been studied by electron microscopy in sections of tissues, buffy coats, and sediments of peritoneal washings of rats, mice, guinea pigs, and men. The core of eosinophil granules is a crystal which has a cubic lattice with a repeat of approximately 30 A in rodents and approximately 40 A in man. The chemical composition of the core is discussed in connection with recent cell fractionation studies, and the hypothesis that the core is a crystal of peroxidase is considered.

THE PATHOLOGIC EFFECTS OF INTRAVENOUSLY ADMINISTERED SOLUBLE ANTIGEN-ANTIBODY COMPLEXES : II. ACUTE GLOMERULONEPHRITIS IN RATS

The intravenous administration to rats of soluble antigen-antibody complexes in antigen excess resulted in acute glomerulonephritis. This occurred with both rabbit antiovalbumin and rabbit anti-BSA systems. The rats so treated regularly showed proteinuria and elevation of blood urea nitrogen. These findings are compared with those reported in rats injected with anti-kidney serum.

SENSITIZATION TO DENATURED AUTOLOGOUS GAMMA GLOBULIN

Immunization of guinea pigs with denatured autologous gamma globulin results in the development of delayed hypersensitivity to some form of gamma globulin. When the autologous gamma globulin is subjected to denaturation with alkaline treatment as employed in this study, guinea pigs regularly develop reactivity to the immunizing material and occasionally to some form of heterologous gamma globulin. With other forms of denaturation, such as produced by urea, ultrasound, or heat, guinea pigs rarely develop sensitivity to the immunizing material but frequently exhibit delayed reactivity to native or denatured heterologous gamma globulin. Reactivity against native autologous gamma globulin does not occur. Guinea pigs immunized with undenatured autologous gamma globulin fail to develop reactivity to any form of gamma globulin. Rabbits immunized with denatured autologous gamma globulin develop circulating antibodies against some form of gamma globulin. Rabbits immunized with alkaline denatured autologous gamma globulin develop antibodies against the preparation used for immunization and against heterologous gamma globulin; rabbits immunized with autologous gamma globulin subjected to freeze-thaw or heat denaturation develop antibodies against heterologous globulin, but antibodies against the immunizing material can only rarely be demonstrated.

[Blood-brain barrier part III: therapeutic approaches to cross the blood-brain barrier and target the brain]

Over the last few years, the blood-brain barrier has come to be considered as the main limitation for the treatment of neurological diseases caused by inflammatory, tumor or neurodegenerative disorders. In the blood-brain barrier, the close intercellular contact between cerebral endothelial cells due to tight junctions prevents the passive diffusion of hydrophilic components from the bloodstream into the brain. Several specific transport systems (via transporters expressed on cerebral endothelial cells) are implicated in the delivery of nutriments, ions and vitamins to the brain; other transporters expressed on cerebral endothelial cells extrude endogenous substances or xenobiotics, which have crossed the cerebral endothelium, out of the brain and into the bloodstream. Recently, several strategies have been proposed to target the brain, (i) by by-passing the blood-brain barrier by central drug administration, (ii) by increasing permeability of the blood-brain barrier, (iii) by modulating the expression and/or the activity of efflux transporters, (iv) by using the physiological receptor-dependent blood-brain barrier transport, and (v) by creating new viral or chemical vectors to cross the blood-brain barrier. This review focuses on the illustration of these different approaches.

[Implication of the blood-brain barrier in neurological diseases: part II]

The main characteristic of the blood-brain-barrier (BBB) is its extremely low permeability, due to tight intercellular endothelial junctions and a variety of transporters, which provides the brain with a unique protection against the potential toxicity of several xenobiotics, but also constitutes a major limitation to drug delivery to the central nervous system. Several dysfunctions of the BBB have been recently implicated in the pathophysiology of neurological diseases: inflammatory, vascular, tumoral, infectious and neurodegenerative diseases. Based on a better knowledge of the BBB biology, new therapeutic strategies are emerging, which by-pass the BBB or take advantage of the selective expression of membrane proteins by brain endothelial cells or circulating leucocytes to target new drugs, such as the anti-VLA4 antibody recently approved for multiple sclerosis treatment. This review will focus on the recently described BBB dysfunctions presumably involved in various neurological diseases.

[Biology of the blood-brain barrier: Part I]

The blood-brain barrier provides the central nervous system with a unique protection against the toxic effects of many xenobiotics. This protection results from the unique anatomic and biological structure of the endothelium of blood vessels in the brain. The main features of the blood-brain barrier are the presence of tight intercellular junctions which strictly limit the diffusion of blood-borne solutes and cells into the brain and the polarized expression of transporters which specifically control the cerebral availability of nutrients, drugs or xenobiotics. Recent findings in molecular and cellular biology improved our knowledge of blood-brain barrier permeability and its regulation. The importance of these findings has been recently highlighted by the description of dysfunctions of the blood-brain barrier which could have an impact on the pathophysiology of several neurological diseases. This review focuses on recent advances in our understanding of blood-brain barrier biology and physiology, presenting the structural organization of the blood-brain barrier and the functional regulation of solute permeability and cellular transendothelial migration.

Evaluation of the femoral midshaft in children with cerebral palsy using magnetic resonance imaging

SUMMARY

Magnetic resonance imaging was used to show that children with quadriplegic cerebral palsy and unable to ambulate independently compared to typically developing children have a remarkably underdeveloped femoral midshaft as indicated by a very thin diameter, a very thin cortical wall, and very low strength estimates.

INTRODUCTION

The femoral shaft is very susceptible to fracture in children with quadriplegic cerebral palsy (QCP); however, its structure and strength have not been evaluated.

METHODS

The volume and width of the middle third of the femur (midfemur) and its cortical wall and medullary cavity were assessed in children with QCP and unable to ambulate independently and typically developing children (n = 10/group) using magnetic resonance imaging (MRI). Estimates of cross-sectional moment of inertia (CSMI), section modulus (Z), and polar moment of inertia (J) were also determined.

RESULTS

Total volume of the midfemur and volume of its cortical wall and medullary cavity were substantially lower in children with QCP than controls (51-55%; p < 0.001). In addition, the total midfemur, its medullary cavity and the anterior, posterior, and lateral sections of its cortical wall were thinner (27-43%) in children with QCP (p < 0.001). The midfemur in children with QCP also had remarkably lower CSMI, Z, and J (60-71%; p < 0.001).

CONCLUSIONS

Children with QCP who lack the ability to ambulate independently have midfemurs that are very thin with very thin cortical walls and very low estimated strength. The disparity can be detected using MRI.

Underdeveloped trabecular bone microarchitecture is detected in children with cerebral palsy using high-resolution magnetic resonance imaging

Using high resolution magnetic resonance imaging, we detected severely underdeveloped trabecular bone microarchitecture in the distal femur of children with cerebral palsy who can not ambulate independently vs. typically developing controls. Furthermore, very good short-term reliability of trabecular bone microarchitecture measurements was observed in both groups of children.

INTRODUCTION

Severe forms of cerebral palsy (CP) are associated with very low areal bone mineral density and a very high incidence of fracture in the distal femur; however, the state of trabecular bone microarchitecture has not been evaluated. Furthermore, the short-term reliability of trabecular bone microarchitecture assessment in children using high-resolution magnetic resonance imaging (MRI) has not been determined.

METHODS

Apparent bone volume to total volume (appBV/TV), trabecular number, (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp) were determined in the distal femur of non-ambulatory children with CP and typically developing children using MRI.

RESULTS

Children with CP had a 30% lower appBV/TV, a 21% lower appTb.N, a 12% lower appTb.Th and a 48% higher appTb.Sp in the distal femur than controls (n = 10/group; P < 0.001). The short-term reliability of the trabecular bone microarchitecture measures was very good, with coefficients of variation ranging from 2.0 to 3.0% in children with CP (n = 6) and 1.8 to 3.5% in control children (n = 6).

CONCLUSIONS

Underdeveloped trabecular bone microarchitecture can be detected in the distal femur of children with CP who can not ambulate independently using high-resolution MRI. Furthermore, MRI can be used to assess trabecular bone microarchitecture in children with a high degree of reliability.