Tibial Bowing Research Articles

Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN): Phenotypic analysis of a new skeletal dysplasia caused by a Lys650Met mutation in fibroblast growth factor receptor 3

We previously discovered a novel missense mutation (Lys650Met) in the tyrosine kinase domain of the fibroblast growth factor receptor 3 (FGFR3) gene in four unrelated individuals with a condition we called "severe achondroplasia with developmental delay and acanthosis nigricans" (SADDAN) [Tavormina et al., 1999: Am. J. Hum. Genet. 64:722-731]. Here we present a more detailed clinical account of the SADDAN phenotype. The FGFR3 Lys650Met mutation results in severe disturbances in endochondral bone growth that approach and overlap those observed in thanatophoric dysplasia, type I. However, this mutation is most often compatible with survival into adulthood. Other unusual bone deformities, such as femoral bowing with reverse (i.e., posterior apex) tibial and fibular bowing and "ram's horn" bowing of the clavicle, are also seen in some patients. In addition to skeletal dysplasia, progressive acanthosis nigricans, and central nervous system structural anomalies, seizures and severe developmental delays are observed in surviving SADDAN patients. Despite its location within the same FGFR3 codon as the thanatophoric dysplasia type II mutation (Lys650Glu) and a similar effect on constitutive activation of the FGFR3 tyrosine kinase, the Lys650Met is not associated with cloverleaf skull or craniosynostosis.

Descriptive analysis of tibial pseudarthrosis in patients with neurofibromatosis 1.

Five percent of individuals with neurofibromatosis type 1 (NF1) present with congenital long bone pseudarthrosis (PA). In large series, 50-80% of patients with congenital long bone PA also have NF1. Very little information exists on the natural history and pathogenesis of PA in NF1. This report is a descriptive analysis of a large series of patients with NF1 and tibial bowing or PA. Study A is a case-control study using the National Neurofibromatosis Foundation International Database (NNFFID). Eighty-five patients with PA were compared to a control group from the same database. There was a statistically significant male predominance of NF1 cases with PA (54 males to 31 females), compared to controls (85 males to 87 females) (chi2 = 4.0, P = 0.046, using a two-tailed test with Yates' correction). There was no significant difference in the clinical presentation of NF1 manifestations in NF1 patients with PA than in NF1 patients without PA. Of the affected individuals with PA, there were 24 de novo cases and 21 familial cases (9 through maternal and 12 through paternal inheritance). Questions that could not be answered by Study A were addressed by a partially overlapping case-series report, Study B, in which data on 75 cases ascertained through questionnaires completed by NF center directors were collected. From Study B we determined that half of the patients who had a fracture sustained it before age 2, and approximately 16% of the pseudarthrosis patients had an amputation. Our data indicate a male predominance and no parent-of-origin effect. Male gender may be a susceptibility factor for pseudarthrosis in NF1.

Blepharophimosis, hypoplastic radius, hypoplastic left heart, telecanthus, hydronephrosis, fused metacarpals, and ?prehensile? halluces: A new syndrome?

We report on the prenatal ultrasound and postnatal findings in an infant born to a healthy, nonconsanguineous couple. The infant had microcephaly, telecanthus, blepharophimosis, cleft palate, micrognathia, abnormally modeled ears, hypoplastic left heart, hypoplastic radii and ulnae with radial subluxation, pseudoarthrotic distal humeri, fused metacarpals, tibial bowing, unusual feet with long halluces, hydronephrosis, patent urachus, abnormal electroencephalogram, and normal karyotype. To our knowledge, this combination of anomalies has not been recognized previously and may represent a new condition.

Blepharophimosis, hypoplastic radius, hypoplastic left heart, telecanthus, hydronephrosis, fused metacarpals, and “prehensile” halluces: A new syndrome?

We report on the prenatal ultrasound and postnatal findings in an infant born to a healthy, nonconsanguineous couple. The infant had microcephaly, telecanthus, blepharophimosis, cleft palate, micrognathia, abnormally modeled ears, hypoplastic left heart, hypoplastic radii and ulnae with radial subluxation, pseudoarthrotic distal humeri, fused metacarpals, tibial bowing, unusual feet with long halluces, hydronephrosis, patent urachus, abnormal electroencephalogram, and normal karyotype. To our knowledge, this combination of anomalies has not been recognized previously and may represent a new condition. Am. J. Med. Genet. 80:309–313, 1998. © 1998 Wiley-Liss, Inc.

FISH analysis of a complex chromosome rearrangement involving nine breakpoints on chromosomes 6, 12, 14 and 16

We report the prenatal diagnosis of an apparently balanced de novo complex chromosome rearrangement (CCR) which involved nine breakpoints on four different chromosomes. Fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY) were performed as an adjunct to G-banding for characterization of the abnormal chromosomes. The 22-week female fetus showed minor dysmorphic features including dolichocephaly, broad fingernails, tibial bowing, clubfoot, thoracolumbar scoliosis and hypoplastic toenails. Autopsy revealed gall-bladder hypoplasia and an atrial septal defect. Chromosome analysis of fetal tissue confirmed the presence of the complex rearrangement.

Medical complications of achondroplasia: a multicentre patient review.

Achondroplasia is the most prevalent chondrodysplasia and numerous authors have documented the varied social and medical complications that may compromise a full and productive life. Complications include cervicomedullary compression, spinal...

Endosteal referencing in revision total knee arthroplasty

A method of orienting the femoral and tibial bone cuts relative to the endosteal cortex of the femur and tibia was used in 32 patients who underwent revision total knee arthroplasty. The mean orientation of the femoral component was 96.74° ± 1.03°, mean orientation of the tibial baseplate was 90.71° ± 1.10°, mean anatomic tibiofemoral alignment was 7.42° ± 1.69° of valgus, and mean mechanical tibiofemoral alignment was 1.09° ± 1.83° of valgus. Mean tibial bowing was 1.63° ± 1.57° of valgus, and mean femoral bowing was 0.58° ± 1.53° of varus. Valgus tibial bowing was correlated with valgus orientation of the tibial component ( r = .86, P < .000001), and varus femoral bowing was correlated with orientation of the femoral component ( r = .54, P = .0054). Referencing the implant position from the endosteal cortex of the intramedullary canals provides a reliable method of achieving satisfactory alignment in most revision total knee arthroplasties; however, bowing of the femur or tibia can affect alignment.

Congenital deficiency of the fibula with ipsilateral iliac horn and absence of the kidney

Congenital deficiency of the fibula is sometimes accompanied by femoral hypoplasia, genu valgum, patellar a/hypoplasia or dislocation, tibial bowing, foot deformity, and toe deficiency in the affected limb. 'Iliac horns' are bony projections extending posterolaterally from the ilium and considered to be pathognomonic of nail-patella syndrome. We report a 5-year-old Japanese girl with congenital complete deficiency of the left fibula, ipsilateral iliac horn and absence of the left kidney.

Longitudinal deficiency of the fibula. Operative treatment.

We reviewed the results of early amputation and prosthetic fitting in twenty-five children (thirty-one extremities) who had longitudinal deficiency of the fibula and were managed between 1977 and 1992. The median age at the time of the initial operation was thirteen months (range, eight months to nine years and eight months). The median duration of follow-up was eight years and ten months (range, two years and six months to sixteen years and eleven months). A Syme amputation was performed on fifteen extremities (thirteen children), and a modified Boyd amputation (which included resection of the distal tibial physis) was performed on sixteen extremities (thirteen children). (One child had a Syme amputation on one side and a Boyd amputation on the other and is thus included in both groups). In twenty-seven extremities, simultaneous excision of the fibular anlage was performed to prevent the development of a deformity secondary to the potential tethering effect. In twelve extremities, a diaphyseal osteotomy of the tibia also was performed to correct tibial bowing and to improve the mechanical alignment of the extremity. At the time of follow-up, the patients who had had a Syme amputation had more problems related to reformation of the calcaneus, instability of the heel pad, prosthetic suspension, and excessive length of the residual extremity. The modified Boyd amputation improved the function of the heel pad and the prosthetic suspension and provided the optimum length of the residual extremity. We also found that an early diaphyseal osteotomy of the tibia to correct severe bowing improved prosthetic fitting. This study did not support the concept that early resection of the fibular anlage or a diaphyseal osteotomy of the tibia prevents the development of hypoplasia of the lateral femoral condyle and associated genu valgum deformity.

Unilateral Duplication of the Great Toe with Anterolateral Tibial Bowing

Summary A syndrome consisting of unilateral duplication of the great toe in association with anterolateral bowing of the tibia is described. Patients with this syndrome have significant pedal difficulties after surgical management, but the tibial bowing spontaneously resolves without treatment. Tibial shortening is noted relative to the fibula. Associated clinodactyly and dysharmonic maturation of carpals and metacarpals are also seen. Current data are most consistent with a developmental rather than a genetic etiology.

Osteofibrous dysplasia: Clinicopathologic study of 80 cases

A thorough review of the clinical, radiologic, and histologic features of 80 cases of long bone osteofibrous dysplasia is presented. Of the six cases of osteofibrous dysplasia immunostained with a cytokeratin antibody, two were cytokeratin positive; however, the five cases of fibrous dysplasia that were stained were all negative. Follow-up (mean, 5.4 years; range, 1 month to 31 years) data were available for 41 cases (51%). From the consultation series nine of the 18 patients studied had recurrences, regardless of the different treatment regimens. The average recurrence interval in these patients was 2.7 years. Two patients had incomplete excision and six had biopsy only. All eight of these patients had residual tumors. Among the 16 Mayo Clinic patients, one had recurrence 5 years after the initial treatment. In two cases, 7-year-old and 6-year-old boys, histologic maturation to fibrous dysplasia was observed 4 and 10 years later, respectively. Adamantinoma has not developed in any of the 41 cases of osteofibrous dysplasia for which we have follow-up information. It seems clear that osteofibrous dysplasia does not progress to adamantinoma. Our study suggests that osteofibrous dysplasia is probably a variant of fibrous dysplasia, as demonstrated by the maturation of two lesions of osteofibrous dysplasia to fibrous dysplasia. Surgical treatment may be appropriate in cases with an extensive lesion, pseudoarthrosis, and accentuated tibial bowing. The overall prognosis is good, even with recurrence.

Campomelic dysplasia: evidence of autosomal dominant inheritance.

We present a mother and daughter with clinical and radiological findings consistent with the diagnosis of campomelic dysplasia. Milder tibial bowing and significant shortening of the phalangeal bones of both...

Avian tibial dyschondroplasia as a cause of bone deformity

The course of tibial dyschondroplasia (TD) was followed in 20 broiler fowl fed ad libitum. TD initially developed between 2 and 5 weeks of age in all the birds. Tibial plateau angles (TP degrees ) were measured in the radiographs and used as an assessment of tibial bowing. There was a significant correlation between abnormal TP degrees and the age of onset, severity and persistence of TD, indicating that TD can be associated with the development of bone deformity in the form of tibial bowing (abnormal TP degrees ). Lameness and abnormal tibiotarsal torsion were only seen in broilers with abnormal TP degrees ; suggesting that altered TP degrees , may through altered biomechanical loading lead to other bone deformities and can contribute to gait abnormalities.

Craniofacial abnormalities in mice with X‐Linked hypophosphatemic genes (Hyp or Gy)

X-Linked hypophosphatemia is the most common cause of metabolic rickets in humans and is characterized by a reduced renal TmP/GFR and hypophosphatemia. Clinically, these changes are associated with growth retardation including attenuated craniofacial growth, femoral and tibial bowing, and radiologic and histomorphometric evidence of rickets and osteomalacia. Similar mutations occur in mice at the Hyp and Gy gene loci. Direct craniometric measurements were made on mouse skulls to investigate the pattern of craniofacial growth differences in the Hyp/+, Hyp/Hyp and Gy/+ genotypes and to compare these to littermate normals in the C57BL/6J mouse strain. There was generalized attenuation in craniofacial growth in all mutants. The heterozygous Hyp and Gy mutants showed similar patterns of craniofacial growth with diminished neurocranial length, viscerocranial length, and mandibular height. The Gy/+ was significantly smaller than the Hyp/+ in neurocranial width. The homozygous Hyp mouse was not affected more severely than the heterozygous Hyp except in overall cranial length, nasal bone length, and mandibular length from mandibular foramen to third molar. In summary, the heterozygous Hyp and Gy mutant mice showed similar patterns of craniofacial growth. The homozygous Hyp mouse was not affected more severely than the heterozygous Hyp except in three of the 15 measured variables. Thus, these data demonstrate the almost complete dominance of the Hyp gene. In contrast, the Gy gene is incompletely dominant. The heterozygous Gy females survive, but the hemizygous Gy males do not, on a C57BL/6J background. This suggests that there is a family of closely linked genes on the X chromosome which, while similar in their effects on phosphate homeostasis, have differing mechanisms of action.

Sibs with a disorder resembling Blount disease (tibia vara)

Radiographic investigation of 3 Turkish sibs presenting with bowed legs disclosed physiological tibial bowing in the 7-month-old girl. Stage I Blount disease in the 26 month-old boy and Stage II Blount disease in the 45 month-old girl. The reported cases provide evidence for autosomal recessive inheritance. This observation points to genetic heterogenity, i.e. the existence of 2 genetically different, but radiologically indistinguishable disorders.

The accuracy of tibial intramedullary alignment devices in total knee arthroplasty

The accuracy of a tibial medullary alignment device is assessed radiographically in 30 varus and 30 valgus knees undergoing total knee arthroplasty. The results suggest that although the device is reliable and accurate for varus knees, it may lead to malalignment of up to 5° in valgus knees. Overall neutral alignment was achieved in 83% of the varus knees and 37% of the valgus knees. Tibial bowing was the main source of error and was present in 66% of the valgus knees, with mean of 3°. Preoperative long films or cross-checking with external alignment devices is recommended to assure neutral alignment in genu valgus deformity.

Rehabilitation of Children and Infants With Osteogenesis Imperfecta

Management of children and infants with osteogenesis imperfecta (OI) poses difficult decisions for pediatricians, orthopedists, and physiatrists. These children are frequently frail with disabling bone and joint deformities and fractures. In an eight-year cumulative management of 12 children with OI, a comprehensive program included strengthening exercises to the pelvic girdle and lower extremity muscles, in addition to pool exercises and molded seating to support upright posture. Long leg braces were fitted when the children were able to sit unsupported. All 12 were fitted with braces; nine were functional ambulators, and three were home ambulators. Six children required femoral plating or rodding, two of whom subsequently had the metal removed. Lower extremity fractures averaged one and one-half per year prior to bracing for nine children who had fractures. There was 0.83 fracture per year for the ten children who had fractures after bracing. The degree of femoral bowing increased in four, decreased in four, and remained unchanged in four, while the degree of tibial bowing increased in two, decreased in nine, and remained unchanged in one during the observation period. A comprehensive rehabilitation program and long leg bracing with surgical operations on the femur result in a high level of functional activity for children with OI with an acceptable level of risk for fracture.

Distal tibial deformity in bowlegs.

Serial radiographic measurements of the tibias of 14 children 12 months to 5 years of age who were being evaluated for bowleg deformities showed both proximal and distal tibial bowing. With time, the distal bowing in both the children with physiologic bowing (metaphyseal/diaphyseal angles of greater than 11 degrees) and those being treated in braces generally decreased. When the ratios of proximal to distal bowing at initial examination were compared with this ratio at the final examination, it was apparent that both the proximal and distal bowing remodeled at approximately the same rate.

Osteogenesis Imperfecta (Correction of Anterior Tibial Bowing): A case report

Osteogenesis imperfecta has been categorized as a heritable disorder of connective tissue affecting both bone and soft tissues and is characterized by fragility of bone, blue sclerae, and deafness, less frequently by dentinogenesis imperfecta and laxity of ligament. The goals of orthopedic management with osteogenesis imperfecta are the treatment of acute fractures and long-term rehabilitation in an effort to maintain ambulation. We report a case of osteogenesis imperfecta with anterior bowing of tibia which was successfully corrected by multiple osteotomies and intramedullary fixation by Sofield method and reviewed literatures.

Posteromedial bowing of the tibia. Progression of discrepancy in leg lengths.

Thirteen children with posteromedial bowing of the tibia were followed clinically and radiographically for a mean of four years from the time of original diagnosis. At follow-up, the discrepancy in leg lengths as determined by scanograms ranged from 1.9 to 5.6 centimeters, with a mean of 3.1 centimeters; usually there was progression of the discrepancy. Nine of the thirteen children had a discrepancy of more than 2.5 centimeters. There appeared to be a direct relationship between the degree of initial tibial bowing and the severity of the subsequent leg-length discrepancy.