Large femoral bone loss after hip revision using the uncemented proximally porous-coated Bi-Metric prosthesis: 22 hips followed for a mean of 6 years

Background and purpose Periprosthetic bone loss after uncemented femoral hip revision is a matter of concern. We have used a proximally porous- and hydroxyapatite-coated prosthesis (Bi-Metric) in revision since 1989 and now we report the bone changes. This prosthesis is intended to distribute the forces more evenly and to avoid proximal femoral unloading.Methods 22 patients were unilaterally reoperated because of aseptic loosening. Only patients with a healthy contralateral hip were included. Mean age at revision was 69 (55–80) years. Bone defects were graded by Gustilo-Pasternak and Endo-Klinik classifications. Clinical assessment was performed with Harris hip score. We used radiographs and dual-energy X-ray absorptiometry to evaluate migration, femoral remodeling, and bone mineral density after 72 (30–158) months.Results The mean Harris hip score was 74 (30–100) points at follow-up. Mild thigh discomfort was present in 1 patient and moderate thigh pain in 3 patients. There was no loosening or subsidence. Osteolysis seen at revision had diminished in 19 of the 22 hips at follow-up. We noted a large reduction in bone mineral density. It was most pronounced in Gruen regions 1, 2, 6, and 7.Interpretation Revision with this stem is a reliable procedure; however, we noted a large degree of proximal bone loss that could lead to later mechanical complications or fractures.     

Bed‐sharing among six‐month‐old infants in western Sweden

Aim: In spite of several reports of an increased risk of sudden infant death syndrome (SIDS) in connection with bed‐sharing, it is not an uncommon practice. The aim of this study was to examine bed‐sharing at 6 months of age and the factors that are associated with bed‐sharing. Methods: Our cohort comprised 8176 randomly chosen families. At 6 month of age, the families received an invitation to the study, with a questionnaire, which was completed by 5605 families (response rate 68.5%). Results: Of the families, 19.8% bed‐shared. In the multivariate analysis, we found a correlation between breast‐feeding and bed‐sharing (breast‐feeding at 6 months: OR 1.94; 95% CI 1.56, 2.41). Moreover, we found an association with 3+ nightly awakenings at 6 months (2.70; 2.20, 3.32). It was more common to share a bed if the parent was single (2.04; 1.19, 3.51) and less common if the infant was bottle‐fed in the first week (0.70; 0.54, 0.90). Never using a pacifier was associated with a higher frequency of bed‐sharing. Conclusion: We found a correlation between breast‐feeding and bed‐sharing as well as between sleeping problems and a single parent. A lower percentage of infants sleeping in the parental bed were seen in association with formula feeding in the first week after birth.     

A second locus (GLC3B) for primary congenital glaucoma (Buphthalmos) maps to the 1p36 region

Primary congenital glaucoma (gene symbol: GLC3) is an ocular disorder that occurs for 0.01-0.04% of blind people. In the majority of familial cases reported so far, this condition is inherited as an autosomal recessive trait. We have recently used a group of 17 GLC3 families with a minimum of two affected offspring and consanguinity in most of the parental generation and mapped the first GLC3 locus (GLC3A) to the 2p21 region. Six families did not show any linkage to the GLC3A locus and thus provided evidence for genetic heterogeneity of this disorder. A total of eight families unlinked to the 2p21 region were used to search for the chromosomal location of the second GLC3 locus. Herein, we describe mapping of a new locus (designated GLC3B) for primary congenital glaucoma to the short arm of chromosome 1 (1p36.2-36.1) that is situated centromeric to the neuroblastoma and Charcot-Marie-Tooth type 2A (CMT2A) loci. A total of 17 DNA markers were genotyped from this region of chromosome 1. Four families showed no recombination with the two markers D1S2834 and D1S402 with a maximum lod score of 4.510 and 4.157 respectively. Pairwise and multipoint linkage analysis and inspection of the haplotypes revealed that the remaining four families are not linked to this part of chromosome 1, thus providing further evidence that at least one more locus for the autosomal recessive form of GLC3 must exist in the genome. Based on the recombination events, the overall linkage map of this region is: tel-D1S1192-D1S1635-D1S1193 - (D1S1597/-D1S489/D1S228)- [GLC3B/D1S2834/D1S402] - (D1S1176/D1S507/D1S407) - D1S2728-(MFAP2/D1S170) - D1S1368 - D1S436- D1S1592-cen.      

Favorably skewed X‐inactivation accounts for neurological sparing in female carriers of Menkes disease

Desai V, Donsante A, Swoboda KJ, Martensen M, Thompson J, Kaler SG. Favorably skewed X‐inactivation accounts for neurological sparing in female carriers of Menkes disease. Classical Menkes disease is an X‐linked recessive neurodegenerative disorder caused by mutations in ATP7A, which is located at Xq13.1‐q21. ATP7A encodes a copper‐transporting P‐type ATPase and plays a critical role in development of the central nervous system. With rare exceptions involving sex chromosome aneuploidy or X‐autosome translocations, female carriers of ATP7A mutations are asymptomatic except for subtle hair and skin abnormalities, although the mechanism for this neurological sparing has not been reported. We studied a three‐generation family in which a severe ATP7A mutation, a 5.5‐kb genomic deletion spanning exons 13 and 14, segregated. The deletion junction fragment was amplified from the proband by long‐range polymerase chain reaction and sequenced to characterize the breakpoints. We screened at‐risk females in the family for this junction fragment and analyzed their X‐inactivation patterns using the human androgen‐receptor (HUMARA) gene methylation assay. We detected the junction fragment in the proband, two obligate heterozygotes, and four of six at‐risk females. Skewed inactivation of the X chromosome harboring the deletion was noted in all female carriers of the deletion (n = 6), whereas random X‐inactivation was observed in all non‐carriers (n = 2). Our results formally document one mechanism for neurological sparing in female carriers of ATP7A mutations. Based on review of X‐inactivation patterns in female carriers of other X‐linked recessive diseases, our findings imply that substantial expression of a mutant ATP7A at the expense of the normal allele could be associated with neurologic symptoms in female carriers of Menkes disease and its allelic variants, occipital horn syndrome, and ATP7A‐related distal motor neuropathy.