Multilayered patella: similar radiographic findings in pseudoachondroplasia and recessive multiple epiphyseal dysplasia

Windswept Deformity a Disease or a Symptom? A Systematic Review on the Aetiologies and Hypotheses of Simultaneous Genu Valgum and Varum in Children

Objective: The objective of this study is to create an overview of the possible aetiologies of windswept deformity and to emphasize the points of attention when presented with a case. Methods: A systematic search according to the PRISMA statement was conducted using PubMed, African Journals Online, Cochrane, Embase, Google Scholar, and Web of Science. Articles investigating the aetiology of windswept deformity at the knee in children, and articles with windswept deformity as an ancillary finding were included. The bibliographic search was limited to English-language articles only. The level of evidence and methodological appraisal were assessed. Results: Forty-five articles discussing the aetiology of windswept deformity were included. A variety of aetiologies can be brought forward. These can be divided into the following groups: ‘Rickets and other metabolic disorders’, ‘skeletal dysplasias and other genetic disorders’, ‘trauma’ and ‘descriptive articles without specific underlying disorder’. With rickets being the largest group. Interestingly, in the group without a specific underlying disorder, all patients were from African descent, being otherwise healthy and presented with windswept deformity between two and three years of age. Conclusion: We have presented an overview that may help identify the underlying disorder in children with windswept deformity. A step-by-step guide for clinicians who see a child with windswept deformity is provided. Even though, according to the Oxford level of evidence, most articles have a low level of evidence.

Imaging of Congenital Skeletal Disorders

Osteochondrodysplasias are the result of the expression of gene mutations. The phenotypes in osteochondrodysplasias evolve through life, with the possibility that previously unaffected bones may be involved at later stages of growth. Due to the variable time of onset, the diagnosis may be made prenatally, at birth, or later. Certainty in the diagnosis is sometimes only achieved as the patient matures and the disease evolves. Radiographic evaluation is a fundamental part of the diagnostic work-up of congenital skeletal disorders and in most cases the first tool used to arrive at a diagnosis. This review describes the imaging characteristics, specific signs, and evolution of several skeletal dysplasias in which diagnosis may be directly or indirectly suggested by radiologic findings. A definitive accurate diagnosis of a congenital skeletal abnormality is necessary to help provide a prognosis of expected outcomes and to counsel parents and patients.

A Novel COMP Mutated Allele Identified in a Chinese Family with Pseudoachondroplasia

Pseudoachondroplasia (PSACH) is an autosomal dominant skeletal dysplasia with an estimated incidence of ~1/60000 that is characterized by disproportionate short stature, brachydactyly, joint laxity, and early-onset osteoarthritis. COMP encodes the cartilage oligomeric matrix protein, which is expressed predominantly in the extracellular matrix (ECM) surrounding the cells that make up cartilage, ligaments, and tendons. Mutations in COMP are known to give rise to PSACH. In this study, we identified a novel nucleotide mutation (NM_000095.2: c.1317C>G, p.D439E) in COMP responsible for PSACH in a Chinese family by employing whole-exome sequencing (WES) and built the structure model of the mutant protein to clarify its pathogenicity. The novel mutation cosegregated with the affected individuals. Our study expands the spectrum of COMP mutations and further provides additional genetic testing information for other PSACH patients.

A novel mutation in exon 11 of COMP gene in a Chinese family with pseudoachondroplasia

Pseudoachondroplasia (PSACH) is a relatively common skeletal dysplasia characterized by disproportionate short stature, joint laxity, early-onset osteoarthrosis, and dysplasia of the spine, epiphysis, and metaphysis. It is known as an autosomal dominant disease which results exclusively from mutations in the gene for Cartilage Oligomeric Matrix Protein (COMP). We have identified a five year old Chinese boy who was diagnosed as pseudoachondroplasia according to clinical manifestations and X-ray symptoms. His mother seems like another effected individual because of the apparent short stature. Genomic DNA was extracted from peripheral blood lymphocytes. DNA sequencing analysis of the COMP gene revealed a heterozygous mutation (c.1219 T > C,p.Cys407Arg) in the patient. His mother was also affected with the same genetic change. Mutations in COMP gene is proved to change the Cartilage Oligomeric Matrix Protein. This missense mutation (c.1219 T > C) has not been reported before and it is not belongs to polymorphism sites. Our results extend the spectrum of mutations in COMP gene leading to pseudoachondroplasia.

Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias

Skeletal dysplasias are not uncommon entities and a radiologist is likely to encounter a suspected case of dysplasia in his practice. The correct and early diagnosis of dysplasia is important for management of complications and for future genetic counselling. While there is an exhaustive classification system on dysplasias, it is important to be familiar with the radiological features of common dysplasias. In this article, we enumerate a radiographic approach to skeletal dysplasias, describe the essential as well as differentiating features of common non-lethal skeletal dysplasias and conclude by presenting working algorithms to either definitively diagnose a particular dysplasia or suggest the most likely differential diagnoses to the referring clinician and thus direct further workup of the patient.

Recessive multiple epiphyseal dysplasia (rMED) with homozygosity for C653S mutation in the DTDST gene--phenotype, molecular diagnosis and surgical treatment of habitual dislocation of multilayered patella: case report

Background

Multiple epiphyseal dysplasia (MED) is one of the more common generalised skeletal dysplasias. Due to its clinical heterogeneity diagnosis may be difficult. Mutations of at least six separate genes can cause MED. Joint deformities, joint pain and gait disorders are common symptoms.

Case Presentation

We report on a 27-year-old male patient suffering from clinical symptoms of autosomal recessive MED with habitual dislocation of a multilayered patella on both sides, on the surgical treatment and on short-term clinical outcome. Clinical findings were: bilateral hip and knee pain, instability of femorotibial and patellofemoral joints with habitual patella dislocation on both sides, contractures of hip, elbow and second metacarpophalangeal joints. Main radiographic findings were: bilateral dislocated multilayered patella, dysplastic medial tibial plateaus, deformity of both femoral heads and osteoarthritis of the hip joints, and deformity of both radial heads. In the molecular genetic analysis, the DTDST mutation g.1984T > A (p.C653S) was found at the homozygote state. Carrier status was confirmed in the DNA of the patient's parents. The mutation could be considered to be the reason for the patient's disease. Surgical treatment of habitual patella dislocation with medialisation of the tibial tuberosity led to an excellent clinical outcome.

Conclusions

The knowledge of different phenotypes of skeletal dysplasias helps to select genes for genetic analysis. Compared to other DTDST mutations, this is a rather mild phenotype. Molecular diagnosis is important for genetic counselling and for an accurate prognosis. Even in case of a multilayered patella in MED, habitual patella dislocation could be managed successfully by medialisation of the tibial tuberosity.

Focal lesions of the patella

Focal lesions of the patella may be identified during the investigation of anterior knee pain or as an incidental finding on radiological images. This pictorial review describes the radiographic appearances of a wide range of conditions that have been seen in this sesamoid bone. Where appropriate, computed tomography and magnetic resonance features have been included.