Resection Arthroplasty Is a Valuable Strategy for Humeroradial Synostosis - A Case Report.

A 15-year-old girl with humeroradial synostosis since birth underwent a resection arthroplasty. A trapezoidal resection osteotomy of approximately 2 cm was performed at the anterior part of the bone flexure. This resulted at 18 months in an elbow arc of motion of 60°-110° and forearm pronation/supination of 40° and 60° without postoperative complications and improved disabilities of the arm, shoulder and hand and Hand 20 scores. Radiographic analysis revealed a humeroradial joint with a maintained pseudarthrosis and hinged motion at the humeroulnar joint. When performed by an experienced surgeon, resection arthroplasty corrects humeroradial synostosis, resulting in improvement in range of motion and quality of life. Level of Evidence: Level V (Therapeutic).

Novel form of rhizomelic skeletal dysplasia associated with a homozygous variant in GNPNAT1.

BACKGROUND: Studies exploring molecular mechanisms underlying congenital skeletal disorders have revealed novel regulators of skeletal homeostasis and shown protein glycosylation to play an important role. OBJECTIVE: To identify the genetic cause of rhizomelic skeletal dysplasia in a consanguineous Pakistani family. METHODS: Clinical investigations were carried out for four affected individuals in the recruited family. Whole genome sequencing (WGS) was completed using DNA from two affected and two unaffected individuals from the family. Sequencing data were processed, filtered and analysed. In silico analyses were performed to predict the effects of the candidate variant on the protein structure and function. Small interfering RNAs (siRNAs) were used to study the effect of Gnpnat1 gene knockdown in primary rat chondrocytes. RESULTS: The patients presented with short stature due to extreme shortening of the proximal segments of the limbs. Radiographs of one individual showed hip dysplasia and severe platyspondyly. WGS data analyses identified a homozygous missense variant c.226G>A; p.(Glu76Lys) in GNPNAT1, segregating with the disease. Glucosamine 6-phosphate N-acetyltransferase, encoded by the highly conserved gene GNPNAT1, is one of the enzymes required for synthesis of uridine diphosphate N-acetylglucosamine, which participates in protein glycosylation. Knockdown of Gnpnat1 by siRNAs decreased cellular proliferation and expression of chondrocyte differentiation markers collagen type 2 and alkaline phosphatase, indicating that Gnpnat1 is important for growth plate chondrocyte proliferation and differentiation. CONCLUSIONS: This study describes a novel severe skeletal dysplasia associated with a biallelic, variant in GNPNAT1. Our data suggest that GNPNAT1 is important for growth plate chondrogenesis.

Comparison of curettage and bone grafting combined with elastic intramedullary nailing vs curettage and bone grafting in the treatment of long bone cysts in children.

To compare the efficacy of curettage and bone grafting combined with elastic intramedullary nailing (EIN) vs curettage and bone grafting in the treatment of long bone cysts in children and to clarify the necessity of using EIN in the treatment of bone cysts.Sixty-two patients were involved in this study from Jan. 2009 to Sept. 2017 (43 males, 19 females; 27 humeri, 35 femurs); the patients were assigned to an EIN group, comprising 30 patients who underwent curettage and bone grafting combined with EIN, or to a non-elastic intramedullary nailing (NEIN) group, comprising 32 patients who underwent curettage and bone grafting alone. The prognosis of the 2 groups was assessed with reference to the standard of Capanna.No statistically significant differences in sex, age, location, activity, pathological fracture, cyst volume, operative time and intraoperative blood loss were found between the 2 groups (P > .05). The effective rate was 90.0% in the EIN group and 68.8% in the NEIN group, and the difference was statistically significant (P < .05).Compared to simple curettage and bone grafting, curettage and bone grafting combined with EIN treatment can significantly improve the prognosis of children with bone cysts. It is recommended that EIN be added to bone cyst curettage and bone grafting.

[Treatment of severe distal humeral bone defects with three-dimensional printing technology].

Objective: To explore the application of three-dimensional (3D) printing technology in precise and individualized surgical treatment of severe distal humeral bone defect. Methods: Five patients with severe distal humeral bone defects were treated with customized 3D printing prostheses between December 2010 and December 2015. There were 4 males and 1 female, with an age of 23-57 years (mean, 35 years); and the length of the bone defect was 5-12 cm (mean, 8 cm). The cause of injury was mechanical injury in 2 cases and strangulation in 3 cases. All of them were the open fracture of Gustilo type Ⅲ. There were 2 cases of radial fracture, 1 case of cubital nerve injury, and 3 cases of radial nerve injury. The time from injury to one-stage operation was 6-18 hours (mean, 10 hours). The operation time, intraoperative blood loss, and intraoperative fluoroscopy were recorded. During follow-up, the anteroposterior and lateral X-ray films of the elbow joints were performed to identify whether there was prosthesis loosening; Mayo Elbow Performance Score (MEPS) and upper extremity Enneking score were used to evaluate limb function. Results: The operation time was 140-190 minutes (mean, 165 minutes). The intraoperative blood loss was 310-490 mL (mean, 415 mL). The intraoperative fluoroscopy was 1-3 times (mean, 1.6 times). Five patients were followed up 14-38 months (mean, 21 months). The wound exudate occurred in 1 case and cured after anti-inflammatory local dressing change; the subcutaneous hematoma occurred in 1 case, and improved after color Doppler ultrasound guided puncture and drainage. The MEPS scores and the Enneking scores were all significantly improved when compared with preoperative ones ( P<0.05). Except MEPS score between 6 and 12 months after operation had no significant difference ( P>0.05), there were significant differences in MEPS scores and Enneking scores between the other time points ( P<0.05). During the follow-up, no prosthetic loosening or joint dislocation occurred. Conclusion: 3D printing technology can achieve personalized treatment of severe distal humeral bone defects, obtain relatively good elbow joint function, and has less postoperative complications and satisfactory effectiveness.

Trabecular bone microarchitecture analysis, a way for an early detection of genetic dwarfism? Case study of a dwarf mother's offspring.

A 66 year-old woman with a disproportionate dwarfism and who bore seven children was discovered at the Middenbeemster archaeological site (The Netherlands). Three are perinates and show no macroscopic or radiological evidence for a FGFR3 mutation causing hypo-or achondroplasia. This mutation induces dysfunction of the growth cartilage, leading to abnormalities in the development of trabecular bone. Because the mutation is autosomal dominant, these perinates have a 50% risk of having been affected. This study determines whether trabecular bone microarchitecture (TBMA) analysis is useful for detecting genetic dwarfism. Proximal metaphyses of humeri were µCT-scanned with a resolution of 7-12 µm. Three volumes of interest were segmented from each bone with TIVMI© software. The TBMA was quantified in BoneJ© using six parameters on which a multivariate analysis was then performed. Two of the Middenbeemster perinates show a quantitatively different TBMA organization. These results and the family's medical history suggest a diagnosis of genetic dwarfism for this two perinates. This study provides evidence to support the efficacy of µCT for diagnosing early-stage bone disease.

Nonsense mutations in FZD2 cause autosomal-dominant omodysplasia: Robinow syndrome-like phenotypes.

Omodysplasia-2 (OMOD2; OMIM%16475) is a rare autosomal dominant (AD) skeletal dysplasia characterized by shortened humeri, short first metacarpal, craniofacial dysmorphism (frontal bossing, depressed nasal bridge, bifid nasal tip, and long philtrum), and variable degrees of genitourinary anomalies. This clinical phenotype overlaps with that of AD type Robinow syndrome. Recently, a mutation in FZD2 encoding a Frizzled Class Receptor 2 has been identified in a family with AD omodysplasia (an affected girl and her affected mother). Here, we present the second report on a heterozygous novel nonsense FZD2 mutation in OMOD2 or Robinow syndrome-like phenotype. The proband was a 16-year-old boy, who has been followed from infancy to adolescence. He presented with rhizomelic short stature with elbow restriction, mild facial dysmorphism (depressed broad bridge, short nose, anteverted nostrils, long philtrum, and low-set ears), and genital hypoplasia. Radiological examination in infancy showed short, broad humeri with relatively narrow distal ends, mildly broad femora, thick proximal ulnae with hypoplastic, dislocated proximal radii, and short first metacarpals. The abnormal skeletal pattern was persistent in adolescence; however, the humeri and femora became less undermodeled, while the humeri and radii became mildly bowed. Molecular analysis identified a de novo, heterozygous, nonsense mutation (c.1640C>A, p.S547*) in FZD2. The affected codon was next to the previously reported mutation (p.Trp548*). The results indicate that OMOD2 or Robinow syndome-like phenotype can be caused by a heterozygous nonsense FZD2 mutation impairing Wnt signaling. Further molecular studies will permit better clarification of the phenotypic spectrum in patients with OMOD2.

Initial Experience With Percutaneous IM Rodding of the Humeri in Children With Osteogenesis Imperfecta.

BACKGROUND: To report a single-center surgical experience treating humeral deformity and fractures in children with osteogenesis imperfecta (OI) using the Fassier-Duval (FD) intramedullary elongating rods. METHODS: A retrospective review was conducted between December 2005 and July 2013 of all OI patients who underwent FD rodding with a minimum of 1-year follow-up. All patients were also being concurrently treated with bisphosphonates. RESULTS: Eighteen patients underwent internal fixation on a total of 35 humeri: 7 males and 11 females with an average age of 49 months. Thirty-five procedures were performed using FD rodding, with 5 utilizing only the male portion. Thirty procedures were primary FD implantation and 5 were revisions. Twelve patients had type III OI and 6 patients type IV OI. Indications for surgery included recurrent fracture, severe bowing deformity, and pain. Osteotomy methods included closed osteoclasis, percutaneous, or open osteotomies. Two patients required transfusions during their hospital stay. At our determined endpoint, 23 humeri (65.7%) had acceptable results with a mean follow-up time of 43 months (SD=27) with no revision. The remaining 12 humeri (34.3%) necessitated revision with a mean time to revision of 35 months (SD=29). Reasons for revision included: migration resulting in pain and functional difficulty (8.6%), migration with bowing (8.6%), and hardware failure secondary to trauma (8.6%). In addition, 2 revisions were required for nonunion (5.7%) and 1 for malunion (2.9%). To our knowledge, all other osteotomies performed during surgery resulted in bony union. CONCLUSIONS: The use of the FD system for correction of humeral deformity demonstrates a reasonable option to improve comfort and function in children with recurrent fractures and deformity secondary to OI. The FD system allows for decreased revision rates and less morbid instrumentation. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Fishtail deformity of the distal humerus: association with osteochondritis dissecans of the capitellum.

BACKGROUND: Fishtail deformity is a rare deformity of the humerus exhibiting concavity of the lateral trochlea, resulting in ulnotrochlear joint derangement. We wanted to share our experience that osteochondritis dissecans of the capitellum is a common associated complication. OBJECTIVE: To summarize imaging of fishtail deformity in children centered on complications of the radiocapitellar joint. MATERIALS AND METHODS: From the radiology information system, we identified all patients <18 years with the diagnosis of fishtail deformity. We included only patients with V-shaped deformity of the distal humerus due to concavity at the lateral trochlea (fishtail deformity). Each patient's initial injury, most recent radiograph and available MRI were evaluated for radiocapitellar joint derangement. RESULTS: Seven patients (4 males) with a mean age of 12.9 years (range: 9.7 to 14.4 years) were identified. Radiocapitellar joint abnormalities were identified in six patients including osteoarthritis (n=5), flattened and sclerotic capitellum (n=4), osteochondritis dissecans (2 associated with loose body, n=4) and radial head subluxation (n=2). In 4 patients, MRI detected changes of osteoarthritis (n=4), osteochondritis dissecans (n=2) and loose body (n=1) not identified on radiography. Two patients with osteochondritis dissecans underwent surgery and one patient has planned surgery. CONCLUSION: Radiocapitellar joint abnormalities (particularly, capitellar osteochondritis dissecans) are common in patients with fishtail deformities. MRI should be performed in these patients since some abnormalities, possibly requiring surgery, are not detected on elbow radiographs.

Severe rhizomelic shortening in a child with a complex duplication/deletion rearrangement of chromosome X.

Mesomelic and rhizo-mesomelic dysplasias are a group of disorders characterized by abnormal shortening of the limbs. One of the most common causes of mesomelic shortening is the loss of the transcription factor SHOX. In this clinical report, we present a patient who in addition to mesomelic shortening has severe rhizomelic shortening and developmental delay. Karyotyping revealed a recombinant X chromosome in which the region distal to Xp22.33 (where SHOX is found) was replaced with material from Xq28. Included in the region distal to Xq28 is the gene MECP2 and this patient presents with features of MECP2 duplication syndrome. We find that this patient has skeletal features not typical with the loss of SHOX that are likely explained by the rearrangement of the X chromosome. Further delineation of this rearrangement may allow for the identification of additional genetic mechanisms critical for the development of the limbs.

[Accurate osteotomy assisted by individualized navigation templates for the treatment of children cubitus varus].

OBJECTIVE: To investigate the feasibility and accuracy of a new navigation template for osteotomy in cubitus varus based on computer assistant design and 3D printing technology. METHODS: The preoperative CT images of 15 children with cubitus varus from June 2015 to June 2016 were collected. According to the above data, the individual osteotomy navigate template match the distal humerus was designed by the software and printed by the 3D printer. Accurate osteotomy was performed with the assistant of the navigate template in the operation. Internal fixation of the osteotomy site was performed with 2 Kirschner wires. After surgery, a long arm plaster was applied with 20° of elbow flexion. All the patients underwent radiographic and clinical evaluations before surgery and at the follow-up examination. RESULTS: During the operation, the navigate template with the individual design of 3D printing technology matched the bony markers of distal humerus. Accurate and simple osteotomy were performed along the resected surface of the navigation template. None of the cases required any kinds of revision surgery or had any complaint of cosmetic appearance. Average union time was 6.7 weeks(ranged, 6 to 8 weeks). Twelve patients got an excellent result and 2 got a good result according to the criteria described by Bellemore. There were no cases with complications of infection or ulnar nerve palsy or joint stiffness. CONCLUSIONS: With the help of 3D printing technology, the accurate osteotomy in cubitus varus assisted by individualized navigate template can be realized. This technology can restore normal anatomical structure of the elbow joint to the greatest extent. It is worthy of popularization and application.

Achondroplasia: Really rhizomelic?

Achondroplasia is the most common form of short limb dwarfism in humans. The shortening of the limb lengths in achondroplasia is widely described as "rhizomelic." While this appearance may be convincing clinically, the description is not necessarily true or helpful radiologically. The aims of this study, were therefore, to determine whether rhizomelic shortening is a true feature of achondroplasia at diagnosis in infancy. Humeral, radial, femoral, and tibial diaphyseal lengths were recorded by two independent observers from 22 skeletal surveys of infants with achondroplasia and compared with 150 normal age-matched control subjects. Upper and lower limb bone length ratios (radial/humeral and tibial/femoral lengths, respectively) in both groups were compared using an unpaired t-test. Mean upper limb length ratios were statistically higher within the achondroplasia group at 0.87 ± 0.04 (n = 22, mean age 70 ± 94 days) compared to normal controls at 0.79 ± 0.02 (n = 150, mean age 113 days ± 88 days; P < 0.0001). Lower limb length ratios were not significantly different between groups (0.84 ± 0.04 vs. 0.83 ± 0.02, P = 0.46). There was good inter-observer agreement of limb length measurements, with an average measurement difference of 0.1 ± 1.4 mm. In conclusion, infants with achondroplasia demonstrate statistically significant rhizomelic shortening within the upper limbs, but not lower limbs at diagnosis, compared to normal controls. The term "rhizomelic shortening" in relation to achondroplasia should be reserved when describing upper limb proportions. © 2016 Wiley Periodicals, Inc.

Duplication of PTHLH causes osteochondroplasia with a combined brachydactyly type E/A1 phenotype with disturbed bone maturation and rhizomelia.

Parathyroid hormone-like hormone (PTHLH, MIM 168470) plays an important role in endochondral bone development and prevents chondrocytes from differentiating. Disease-causing variants and haploinsufficiency of PTHLH are known to cause brachydactyly type E and short stature. So far, three large duplications encompassing several genes including PTHLH associating with enchondromatas and acro-osteolysis have been described in the literature. Here, we report on a three-generation pedigree with short humerus, curved radius, and a specific type of severe brachydactyly with features of types E and A1 but without the enchondromatas and the acro-osteolysis. Microarray-based comparative genomic hybridization (array-CGH) revealed a 70-kb duplication on chromosome 12p11.22 encompassing only PTHLH. Our data extend the phenotypic spectrum associated with copy number variations of PTHLH, and this family is to our knowledge the first description harboring a microduplication encompassing only PTHLH.

A mutation in FRIZZLED2 impairs Wnt signaling and causes autosomal dominant omodysplasia.

Autosomal dominant omodysplasia is a rare skeletal dysplasia characterized by short humeri, radial head dislocation, short first metacarpals, facial dysmorphism and genitourinary anomalies. We performed next-generation whole-exome sequencing and comparative analysis of a proband with omodysplasia, her unaffected parents and her affected daughter. We identified a de novo mutation in FRIZZLED2 (FZD2) in the proband and her daughter that was not found in unaffected family members. The FZD2 mutation (c.1644G>A) changes a tryptophan residue at amino acid 548 to a premature stop (p.Trp548*). This altered protein is still produced in vitro, but we show reduced ability of this mutant form of FZD2 to interact with its downstream target DISHEVELLED. Furthermore, expressing the mutant form of FZD2 in vitro is not able to facilitate the cellular response to canonical Wnt signaling like wild-type FZD2. We therefore conclude that the FRIZZLED2 mutation is a de novo, novel cause for autosomal dominant omodysplasia.

Stress fracture of the supracondylar process of the humerus in a professional tennis player.

The supracondylar process of the humerus is an anatomic variant present in 1% of the population associated with a fibrous band, the ligament of Struthers that attaches it to the medial epicondyle, and may serve as a proximal origin of a fascicle of the pronator teres. Fractures of the supracondylar process of the humerus are extremely rare. To the best of our knowledge, this is the first report of a stress fracture of the supracondylar process. We present the case of a professional tennis player with a stress fracture of the supracondylar process who underwent surgery to avoid possible displacement and neurovascular complications. Clinicians should consider the diagnosis of a supracondylar process fracture with or without neurovascular compression when examining athletes with otherwise unexplained arm or elbow pain. Stress fracture of the supracondylar process may be secondary to the excessive traction of the pronator teres.

Radiologic findings of Patterson-Lowry rhizomelic dysplasia in two sisters.

We report two sisters who have a rare skeletal abnormality termed Patterson-Lowry rhizomelic dysplasia. The typical findings of these cases on bone survey are isolated shortening and proximal metaphyseal enlargement and cupping of the bilateral humeri. The elder sister also has coxa vara deformity and dysplastic proximal femoral epiphyses on both sides. The younger sister has normal hip joint bones bilaterally, but her proximal femoral epiphyses are smaller than normal. All other bones of the sisters are of normal size and configuration. Our patients are two siblings, and their parents are first degree relatives, suggesting autosomal-recessive (AR) inheritance. The present patients help us to understand the genetic relationships and skeletal variabilities of this rare entity.

Long-term observation of a patient with dominant omodysplasia.

We report on the natural history of a female with dominant omodysplasia, a rare osteochondrodysplasia with short stature, rhizomelia of the extremities (upper extremities more affected), and short first metacarpals. The proband had normal molecular analysis of the glypican 6 gene (GPC6), which was recently reported as a candidate for autosomal recessive omodysplasia. The findings in this patient were compared to other known and suspected cases of autosomal dominant omodysplasia. Mild rhizomelic shortening of the lower extremities has not been previously reported.

The Liebenberg syndrome: in depth analysis of the original family.

The Liebenberg syndrome was first described in 1973 in a five- generation family. A sixth generation was added in 2001, and in 2009 a hitherto unknown branch of the same family with similar anomalies extended the family tree significantly. This article describes the clinical findings and illustrates the abnormalities with radiographs and three-dimensional computed tomography scans. We discuss the genetic abnormality that causes Liebenberg syndrome, the genomic rearrangement at the PITX1 locus on chromosome 5.The structural variations seem to result in an ectopic expression of paired-like homeodomain transcription factor 1 (PITX1) in the forelimb causing a partial arm-to-leg transformation in these patients.

Foetal serum but not urinary ß2-microglobulin correlates with histological injury to the kidney.

In a context of foetal obstructive uropathies, biochemical markers can be helpful to assess the renal function, but most studies to date have focused on their correlation with ultrasound findings and neonatal outcome. Our aim was to evaluate foetal ß2-microglobulin as an index of histological injury to the kidney. ß2-microglobulin was measured in serum and/or urine from 27 foetuses with bilateral obstructive uropathy, and compared to the findings of kidney examination following the termination of pregnancy. In serum, increased ß2-microglobulin levels correlated to a decreased number of glomeruli, a reduction in the blastema and the presence of primitive ducts reflecting renal hypoplasia and dysplasia. However, elevated ß2-microglobulin levels in the urine correlated only to a decreased number of glomeruli.

Role of hybrid monolateral fixators in managing humeral length and deformity correction.

BACKGROUND AND PURPOSE: Humeral lengthening and deformity correction are now being done increasingly for various etiologies. Monolateral external fixators have advantages over traditional Ilizarov circular fixators; they are easy to apply, they are less bulky, and they are therefore more convenient for the patient. We assessed the effectiveness of hybrid monolateral lateral fixators in humeral lengthening and deformity correction. METHODS: We retrospectively reviewed 23 patients (40 humeri) with various pathologies who underwent lengthening-with or without deformity correction using monolateral external fixator-between 2003 and 2008. Mean age at the time of the surgery was 14 (10-22) years. The mean follow-up time was 3.4 (1-7) years. RESULTS: The average duration of external fixator use was 8.3 (6-19) months. The mean lengthening achieved was 8.8 (4-11) cm and percentage lengthening was 49% (19-73). The healing index was 28 (13-60) days/cm. The major complications were refracture in 3 humeri and varus angulation of 2 humeri. The minor complications were superficial pin tract infection (6 segments), transient radial nerve palsy (1 segment), and elbow flexion contracture (5 segments). All complications resolved. INTERPRETATION: Hybrid monolateral fixators can be used for humeral lengthening and deformity correction. The advantage over circular fixators is that they are less bulky and patients can perform their day-to-day activities with the fixator in situ.