[Principles in motion...conservative treatment of orthopedic diseases in children].
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Child↗
Biomedical subjects
C Carstens
Publications and source records attributed to C Carstens.
[Biomechanical properties of bioabsorbable cannulated screws for surgical fixation of dislocated epiphysiolysis capitis femoris].
Bioabsorbable materials are well suited for fixation of slipped capital femoral epiphysis (SCFE) as they are resorbable, compatible with magnetic resonance imaging, and well tolerated by the pediatric population. We compared cannulated 4.5-mm bioabsorbable screws made of self-reinforced polylevolactic acid (SR-PLLA) to cannulated 4.5-mm steel and titanium screws for their resistance to shear stress and ability to generate compression in a polyurethane foam model of SCFE fixation. The maximum shear stress resisted by the three screw types was similar (SR-PLLA 371 +/- 146, steel 442 +/- 43, titanium 470 +/- 91 MPa, NS). The maximum compression generated by both the SR-PLLA screw (68.5 +/- 3.3 N) and the steel screw (63.3 +/- 5.9 N) was greater than that for the titanium screw (3.0 +/- 1.4 N, p < 0.05). These data suggest that cannulated SR-PLLA screws have sufficient biomechanical strength to be used in the treatment of SCFE.
Absorbable Implants↗
[Post-traumatic loss of function and malunion of the elbow].
Post-traumatic contracture and malunion of the elbow in pediatric patients may result from a combination of injury-related, diagnostic-related and therapy-related factors. Typical pediatric elbow injuries are associated with different patterns of these risk factors. Etiological differentiation allows for initial risk prediction, improves diagnostic awareness and provides adequate treatment in order to prevent unsatisfactory results.
Child↗
Long-term review of the lumbar spine in javelin throwers.
We studied 21 former top-class competitive javelin throwers to investigate radiological and clinical symptoms in the lumbar spine many years after the end of their athletic careers. The athletes underwent clinical and radiological examinations at an average of 20 years after retiring from athletics. The Hannover questionnaire was used to evaluate functional restrictions in daily living. Degenerative changes in the lumbar spine were more marked towards the caudal aspect of the spine. Ten athletes also had spondylolisthesis, but with little progression (< 15%) throughout the observation period. Athletes both with and without radiologically demonstrated spondylolisthesis, complained of no more back problems than the normal population (93% for athletes v 86% for controls). Slight progression followed their retirement from athletics.
Adult↗
The effect of spinal fusion on the long-term outcome of idiopathic scoliosis. A case-control study.
We have investigated the effect of multisegmental spinal fusion on the long-term functional and radiological outcome in patients with scoliosis. We compared these patients both with those whose spine had not been fused, and with a control group. We studied 68 patients with idiopathic scoliosis (34 operative and 34 non-operative) who had been followed up for a minimum of five years after treatment. They were matched for age (mean 44 years) and Cobb angle (mean 54 degrees) at follow-up. An age- and gender-matched control group of 34 subjects was also recruited. All participants completed a questionnaire to assess spinal function and to grade the severity of back pain using a numerical rating scale. Radiographs of the spine were taken in the patients with scoliosis and lumbar degenerative changes were recorded. The spinal function scores for the patients with scoliosis who had had a fusion were similar to those who had not. Both scoliosis groups, however, had lower scores than the control group (p < 0.001). The frequency and severity of back pain were lower for patients with scoliosis and fusion than for those without, but higher for both scoliosis groups compared with the control group. Radiographs showed similar degenerative changes in both scoliosis groups.
Adult↗
Surgical management of paralytic scoliosis in myelomeningocele.
A retrospective analysis of 54 patients with paralytic scoliosis due to myelomeningocele, who underwent surgical treatment, was performed. The aim of this study was to compare different surgical techniques and to identify clinical parameters influencing primary and midterm results. Three surgical techniques were used: 1) group I, posterior fusion/instrumentation; 2) group II, anterior fusion/no instrumentation combined with posterior fusion/instrumentation; and 3) group III, anterior and posterior fusion/instrumentation. Average age at surgery was 13.1 years. A preoperative scoliosis angle of 90 degrees [interquartile range (25th-75th percentile) (IQR), 76-106 degrees] was primarily reduced to 38 degrees (IQR, 30-50 degrees). At final follow-up (mean, 3.3 years), correction deteriorated to 44 degrees (IQR, 38-65 degrees). The group III procedure resulted in a better midterm correction of scoliosis compared with group I (P = 0.02). The extension of anterior fusion correlated with primary and midterm correction of scoliosis (P < 0.03). Patients with a thoracic level of paralysis had a higher relative loss of correction compared with patients with a lumbar level (P < 0.06). This finding can be attributed mostly to group I patients (P = 0.011). Hardware complications occurred in 16 patients (30%). Relative loss of correction among these patients was high (P < 0.01) and relative midterm correction low (P = 0.001). We recommend anterior and posterior fusion, each with instrumentation for the treatment of paralytic scoliosis in myelomeningocele. In patients with a thoracic level of paralysis, the two-stage procedure is mandatory to reduce the risk of hardware complications and subsequent major loss of correction.
Female↗
Congenital limb deficiences associated with Klippel-Feil syndrome: a survey of 57 subjects.
We reviewed data from 57 patients (40 women) with Klippel-Feil syndrome to identify and characterize limb deficiencies. The cervical synostosis was classified according to the description of Feil (1919). Limb deficiencies were classified according to Henkel et al. (1978) and compared with the sclerotome theory of McCredie and Willert (1999). In a wide variety of combinations of Klippel-Feil syndrome (types I-III) and other anomalies, only 5 patients had a longitudinal upper limb deficiency (one arm or both arms). 4 patients had Klippel-Feil syndrome type II and 1 had type I. 4 patients had "longitudinal distal radial deficiencies", Henkel types 1, 2, 4 and 5 and 1 patient showed "longitudinal combined humero-ulna deficiencies" types 2 and 3 of both arms. The lower limb was not affected. The combination of Klippel-Feil syndrome and upper limb deficiency shows that the defect occurred between the 4th and 5th week of gestation. Sclerotome 6 was mainly affected in our study. In 4 of the 5 patients, the cervical fusion level and sclerotome level of the limb deficiency clearly or partly matched, whereas there was no agreement in 1 patient.
Adolescent↗
Invariant chains with the class II binding site replaced by a sequence from influenza virus matrix protein constrain low-affinity sequences to MHC II presentation.
Presentation of antigenic peptides by MHC II molecules is required to initiate CD4 T(h) cell responses. Some peptides, however, because of low affinity for MHC II, are not efficiently presented. A segment of the MHC II chaperon molecule, invariant chain (Ii), is known to bind early in biosynthesis with low affinity to the peptide binding groove. Here we have exploited the properties of Ii to manipulate the MHC II-loading pathway and to present low-affinity sequences. We used a deletion mutant of Ii where the promiscuous binding site to MHC II, which is adjacent to the groove binding segment, was deleted. A recombinant Ii (rIi) chimera, derived from this construct, was made in which the class II binding segment was exchanged for wild-type or single amino acid substitution variants of an HLA-DR1-restricted sequence from influenza matrix protein (MAT), which leads to MHC II allotype-specific binding. This rIi was expressed in antigen-presenting cells (APC) and introduced the MAT sequence into the MHC II-processing pathway. As expected, rIiMAT elicited antigen-specific, DR1-restricted T cell cytokine production and proliferation. Significantly, rIiMAT, that binds the HLA-DR4 allele with low affinity, elicited DR4-restricted IL-2 production but not proliferation. In contrast, exogenously provided MAT peptide failed to elicit any responses from DR4-restricted T cells. Compatible results were obtained with a single amino acid substitution variant (MAT(T)), which binds with high affinity to DR4 but low affinity to DR1. We conclude that loading of MHC II with antigenic peptides from endogenously synthesized rIi chimeras allows presentation of low-affinity sequences that cannot be presented if provided exogenously as peptides. Ii fusion proteins containing low-affinity antigenic sequences might be useful for vaccination with tumor antigens to overcome deficiencies in antigen presentation.
Adult↗
Results of kyphectomy with the technique of Warner and Fackler in children with myelodysplasia.
Pathological lumbar kyphosis occurs in approximately 8% to 20% of patients with myelomeningocele. During the past 4 years, nine patients with an average preoperative kyphosis of 152 degrees were surgically corrected. They had a short fusion and a long stabilization with Luque rod instrumentation using a technique described by Warner and Fackler (1993). The average degree of correction was 104 degrees and, on average, 2.5 vertebrae were resected. The average surgical time was 225 minutes, and blood loss averaged 635 ml. We saw two complications: one penetration of the distal part of the rod through the sacrum after 32 months, and a dislocation of the rods out of the first sacral foramen after 33 months. From our experience, this procedure is highly demanding, but effective. It should be limited to patients below the weight of 30 kg.
Adolescent↗
Complications of scoliosis surgery in children with myelomeningocele.
The purpose of the present study was to evaluate whether the high incidence of complications in scoliosis surgery in myelomeningocele (MMC) could be attributed to the surgical technique and whether improvements were possible. Between 1984 and 1996, 77 patients with MMC and scoliosis were treated surgically. The clinical and radiological follow-up ranged from 1 to 10 years with a mean follow-up of 3.6 years. The mean age at time of surgery was 12 years 8 months. The average preoperative scoliosis measured 90.20 degrees and was corrected by 47%. The first four patients were stabilized with Harrington rods after anterior correction with a Zielke device (group 1). Twenty-five patients were operated only from posterior, using Cotrel-Dubousset (CD) instrumentation (group 2). In 13 patients an anterior release and discectomy was performed prior to CD posterior instrumentation (group 3). In 26 patients (group 4) this was combined with an anterior instrumentation. The 9 patients of group 5 had congenital vertebral malformations which made a special treatment necessary. Complications could be divided into hardware problems, such as implant failure, dislocation or pseudarthrosis, infections, anesthetic, and neurologic complications. Hardware problems were seen in 29% of all patients. More hardware problems were seen with the Harrington rod (75%) and after solitary posterior instrumentation (30%). The occurrence of pseudarthrosis was dependent on the surgical technique, the extent of posterior spondylodesis, and lumbosacral fusion. Patients with hardware problems had a mean loss of correction of 49% compared to 13% in the other patients. Depending on the different surgical techniques a loss of more than 30% was seen in 12-75% of the cases. Early postoperative shunt failure occurred in four cases; delayed failure - after more than 1 year - in three cases. One patient died within 1 day due to an acute hydrocephalus, another died after 2 1/2 years because of chronic shunt insufficiency with herniation. Wound problems were not dependent on the surgical technique, but on the extent of posterior spondylodesis and the lumbosacral fusion. Based on this analysis we believe our current practice of instrumented anterior and posterior fusion is justified. Further, we are very careful to check shunt function prior to acute correction of spinal deformity.
Adolescent↗
C-terminal extension of the MHC class II-associated invariant chain by an antigenic sequence triggers activation of naive T cells.
In vitro and in vivo activation of T cells was investigated with invariant chain-antigen fusion protein. The CD4 T cell epitope amino acid 52-61 of hen egg lysozyme (HEL) was attached to the C-terminal end of invariant chain (Ii). Expression of this recombinant Ii HEL directs the T cell epitope to the class II processing pathway. Class II molecules of transfected antigen presenting cells (APC) are charged with this HEL epitope. The endogenously provided epitope competes with processing and presentation of exogenously added antigen. APC expressing recombinant Ii HEL stimulate a maximal IL-2 response of HEL-specific T hybridoma cells. Nonprofessional APC expressing recombinant Ii HEL and H2-Ak are also able to activate naive T cells from 3A9 TCR transgenic mice, a result not achieved with peptide pulsed APC. To elicit an in vivo immune response dendritic cells (DC) were transfected with rIi HEL cDNA: following immunization of CBA mice with transfected DC, a primary T cell response against the HEL epitope was induced. Thus the procedure described here could be used to introduce antigens into the class II processing pathway and to elicit T cell activation both in vitro and in vivo.
Alcohol Oxidoreductases↗
Identification of a sequence that mediates promiscuous binding of invariant chain to MHC class II allotypes.
The invariant chain (Ii) shows promiscuous binding to a great variety of MHC class II allotypes. In contrast, the affinities of the Ii-derived fragments, class II-associated Ii peptides, show large differences in binding to class II allotypes. The promiscuous association of Ii to all class II polypeptides therefore requires an additional contact site to stabilize the interaction to the polymorphic class II cleft. We constructed recombinant molecules containing the class II binding site of Ii (CBS) and tested their association with HLA-DR dimers. The CBS fused to the transferrin receptor mediates binding of transferrin receptor-CBS to class II dimers. Within the CBS, deletion of a sequence N-terminal to the groove-binding motif abolished binding of Ii to DR. A promiscuous class II binding site was identified by reinsertion of the N-terminal residues, amino acids 81-87, of Ii into an Ii mutant that lacks the groove-binding segment. DR allotype-dependent association of Ii was achieved by insertion of antigenic sequences. The promiscuous association, in contrast to the class II allotype-dependent binding of Ii, is important to prevent interaction of class II dimers to nascent polypeptides in the endoplasmic reticulum.
Amino Acid Sequence↗
Thanatophoric dysplasia type II: new entity?
There is some question about whether the two forms of thanatophoric dysplasia (TD), Type II with and Type I without cloverleaf skull, belong to the same entity. Thus, we investigated one 6-day-old TD with cloverleaf skull using examination of the external phenotype, radiology, autopsy, skeleton preparation, large section histology, detailed section histology, and ultrastructure. The loss of the three-phase contours-characteristics for Type I (54)--in certain metaphyses, the absence of the perichondral spurs to some extent, and their substitution by a structure similar to the perichondral "ring of Lacroix" have a suggested origin in normal cartilage-bone tissue. The same mechanism is postulated (a) for the appearance of less bent or normally shaped tubular bones compared with TD Type I, and their corresponding increased mechanical stability, and (b) for the less amount of platyspondyly in Type II than in Type I. We suggest that the malformation of the cloverleaf skull has its origin in the promontory growth of the relatively normal cartilage-bone tissues at the skull base resulting in an early synostosis and a consecutive fusion of the cranial sutures. The ultrastructural analysis of chondrocytes demonstrates the significant contribution of electron microscopy for TD studies. We suggest that pathologically altered light chondrocytes accounts for plump cross-striated collagen fibrils, the reduced cellular proliferation, and the impaired formation of columnar and hypertrophic zones. It is clear that normal cartilage-bone tissue distributed among "thanatophoric" tissue is the reason for the differences between Type I and Type II. Hypotheses are presented that explain this tissue mosaicism. Thus, TD Type I and TD Type II do not represent two different entities but the same entity with varying features due to mutational events occurring at different times.
Bone and Bones↗
Sequence divergence of measles virus haemagglutinin during natural evolution and adaptation to cell culture.
Phylogenetic analysis of the sequence of the H gene of 75 measles virus (MV) strains (32 published and 43 new sequences) was carried out. The lineage groups described from comparison of the nucleotide sequences encoding the C-terminal regions of the N protein of MV were the same as those derived from the H gene sequences in almost all cases. The databases document a number of distinct genotype switches that have occurred in Madrid (Spain). Well-documented is the complete replacement of lineage group C2, the common European genotype at that time, with that of group D3 around the autumn of 1993. No further isolations of group C2 took place in Madrid after this time. The rate of mutation of the H gene sequences of MV genotype D3 circulating in Madrid from 1993 to 1996 was very low (5 x 10(-4) per annum for a given nucleotide position). This is an order of magnitude lower than the rates of mutation observed in the HN genes of human influenza A viruses. The ratio of expressed over silent mutations indicated that the divergence was not driven by immune selection in this gene. Variations in amino acid 117 of the H protein (F or L) may be related to the ability of some strains to haemagglutinate only in the presence of salt. Adaptation of MV to different primate cell types was associated with very small numbers of mutations in the H gene. The changes could not be predicted when virus previously grown in human B cell lines was adapted to monkey Vero cells. In contrast, rodent brain-adapted viruses displayed a lot of amino acid sequence variation from normal MV strains. There was no convincing evidence for recombination between MV genotypes.
Animals↗
Development of pathological lumbar kyphosis in myelomeningocele.
We analysed the cases of lumbar kyphosis in 151 (21%) of a series of 719 patients with myelomeningocele. Three different types were distinguished: paralytic, sharp-angled and congenital. In a cross-sectional and partly longitudinal study the size and magnitude of the kyphosis, the apex of the curve and the level of paralysis of each group were recorded and statistically analysed. Paralytic kyphosis (less than 90 degrees at birth) occurred in 44.4% and increased linearly during further development. Sharp-angled kyphosis (90 degrees or more at birth) was present in 38.4% and also showed a linear progression. In both types, progression seemed to depend also on the level of paralysis. Congenital kyphosis occurred in 13.9% and we could find no significant factor which correlated with progression.
Cross-Sectional Studies↗
Late results after subtrochanteric angulation osteotomy in young patients.
Young patients with painful congenital dislocation of the hips need surgery if conservative treatment is unsuccessful. A total of 24 patients after 28 subtrochanteric angulation osteotomies without resection of the femoral head were followed up (mean, 17 years) to evaluate long-term results. Most patients maintain improved function: 20 hips showed persistent gain of abduction, 14 patients showed improvement of gait, and 18 patients described less pain. The degree of angulation must equal the inclination of the pelvic wall to influence hip stability as well as hip range of motion. Osseous reactions of support-seen in 10 hips-are not proof of operative success. Angulation osteotomy does not exclude later surgical procedures such as total hip replacement.
Adolescent↗
Intense gallbladder uptake associated with chemotherapy. An unusual finding in pediatric skeletal scintigraphy.
Focal and diffuse hepatic uptake of bone-seeking radiopharmaceuticals may be due to a variety of conditions including tumors and radiopharmaceutical impurity. However, uptake in the gallbladder is unusual with currently used skeletal agents. Three patients (aged 10, 15, and 16 years) underwent routine whole-body bone scans during a course of intensive chemotherapy with VP-16 and ifosphamide. Images showed intense gallbladder and faint liver uptake. No patient had symptoms of cholecystitis. Radiopharmaceutical quality control revealed no impurities. Repeat bone scans after completion of chemotherapy showed no liver or gallbladder uptake. The authors conclude that this finding represents altered distribution induced by the chemotherapy regimen, and should not be misinterpreted as intrinsic liver or gallbladder disease.
Adolescent↗