暂无摘要。

Few articles have reported on the treatment of Masada type 2 forearm deformities in hereditary multiple exostosis, possibly because of the high redislocation rate and other complications. This study precisely declares the use of modified ulnar lengthening by an Ilizarov external fixation with tumour excision for the treatment of Masada type 2 forearm deformities. 20 children with Masada type 2 forearm deformities were admitted for surgical treatment at our hospital from February 2014 to February 2021. There were 13 girls and 7 boys, ranging in age from 3.5 to 15 years (mean: 9 years) at the time of operation. We removed the prominent osteochondromas of the distal ulna and the proximal radius, positioned a classic Ilizarov external fixator on the forearm and then performed ulnar transverse one-third proximal diaphyseal subperiosteal osteotomy. We adopted modified ulnar lengthening postoperatively. The effects of surgical correction of deformity and functional improvement of the limb were assessed via regular follow-up and X-ray. The patients were followed up for 36 months, and the ulna was lengthened 26.99 mm on average; all radial heads remained relocated. The radiographic evaluations, including relative ulnar shortening, radial articular angle, and carpal slip, were improved. The functions of the elbow and forearm were all improved after surgery. Modified ulnar lengthening by an Ilizarov external fixation with tumour excision for the treatment of Masada type 2 forearm deformities in hereditary multiple exostoses has been proven to be an effective and reliable technique in the early stage.

暂无摘要。

Ulna distraction by monolateral external fixator (MEFix) is a good option for the treatment of Masada type I and IIb deformities in children with hereditary multiple exostoses (HMEs). However, there is no consensus regarding where to perform ulnar osteotomy. Our hypothesis is that osteotomy at the proximal third of the ulna and progressive distraction with MEFix can simultaneously correct elbow and wrist deformities in patients with HME.
We retrospectively reviewed patients with HME who underwent ulna distraction osteogenesis from June 2014 to March 2019. The carrying angle (CA), radial articular angle (RAA), ulnar variance (UV), radial variance (RV) and range of motion (ROM) of the affected forearm and elbow were clinically assessed before lengthening and at the last follow-up visit. The total ulna lengthening distance (LD) and radiographic outcome were also recorded.
Nineteen patients (20 forearms) with HME aged 9.1 ± 2.4 years at the time of surgery were retrospectively reviewed. The mean follow-up period was 26.1 ± 5.6 months. There were 11 patients (12 forearms) with Masada type I deformities and eight patients (8 forearms) with Masada type IIb deformities. Patients with type IIb deformity had higher RV, lower CA values, less elbow flexion and forearm pronosupination than those with type I deformity (p < 0.05); RV was an independent risk factor for radial head dislocation, with the cut off at RV > 15.5 mm. The mean LDs in patients with type I and type IIb deformities were 33.6 ± 6.6 mm and 41.4 ± 5.4 mm, respectively. The mean CA, UV, RV, forearm pronation and ulna deviation at the wrist improved significantly following surgery in all patients. In particular, five of eight patients (62.5%) with type IIb deformities had concentric reduction of the radiocapitellar joint, while no radial head subluxation was detected in patients with type I deformities at the last follow-up. Three complications were recorded: two pin-track infections and one delayed union.
Distraction osteogenesis at the proximal third of the ulna provides satisfactory clinical and radiological outcomes in patients with Masada type I and IIb deformities. Early treatment of Masada type I deformities is indicated before progression to more complex type IIb deformities.

OBJECTIVE: In this study, we present a specified hinge positioning method to achieve satisfying and steerable lengthening and angulation to correct forearm multiple hereditary exostoses (MHE) combined with severe radiocapitellar joint dislocation using Ilizarov ring fixators.
METHODS: Between January 2014 and December 2018, a total of 30 forearms of 23 patients (11 males, 12 females; mean age: 18.3±6.8 years; range, 8 to 35 years) who suffered from type IIa (n=2) or IIb (n=28) MHE with severe radiocapitellar joint luxation were retrospectively analyzed. All patients were treated with Ilizarov external fixators with our specified hinge positioning method. Range of motion of the elbow, forearm and wrist and Visual Analog Scale (VAS), as well as Disabilities of Arm, Shoulder, and Hand (DASH) score, and radiological parameters, including radial articular angle (RAA), ulnar variance (UV) and carpi slip (CS), were recorded preoperatively and at final follow-up and were compared.
RESULTS: Clinical and radiological outcomes were evaluated. Range of motion of the elbow, forearm and wrist, VAS, DASH and radiological features, including RAA, CS, and UV were significantly improved, except for range of motion of the forearm supination. Temporary nail track infection was seen in two of the forearms and was controlled with oral antibiotics. None of the patients developed radial head dislocation again.
CONCLUSIONS: Clinical and radiological outcomes of this novel hinge positioning method are satisfactory in treating MHE with severe radial head dislocation, and this method can be an alternative treatment for MHE by setting a milestone for accurate radiocapitellar joint reduction.

The aim of the present study was to report a clinical survey of hereditary multiple exostoses (HME) in a large Chinese pedigree, and the identification of a novel deletion mutation of exostosin glycosyltransferase 2 (EXT‑2) gene. A patient with multiple exostoses with huge cartilage‑capped tumors in scapula, knees and ankles received surgery in Department of Orthopedics (Shanghai Changhai Hospital). A total of 20 family members were recruited to the study, with seven members (five male; two female) diagnosed as HME. The family members of the patients with HME were examined, clinical data and peripheral blood samples were collected, and their DNA was sequenced. The incidence of HME in this family pedigree was 35%. Exostoses were most frequently in the tibiae with occurrence in six patients, followed by ribs, femurs, radii, fibulae, scapulae and humeri. DNA sequencing of peripheral blood revealed a novel deletion mutation, c.824‑826delGCA, in exon 5 of the EXT‑2 gene, which was observed in all the patients with HME, but not in the healthy family members. Several characteristics of HME in the pedigree were observed, such as susceptibility of male gender, decreased average age of onset and height and increased severity of clinical symptoms with generations.

Genu valgus is one of the most common limb deformities in hereditary multiple exostoses (HME). However, it is easily concealed and may account for subsequent osteoarthritis of the knee. The knees of 56 patients (33 men and 23 women) with HME were investigated bilaterally. Knee valgus was described by the mechanical axis deviation (MAD), mechanical lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA). We investigated sex, age, BMI, total number of palpable osteochondromas, number of radiographic osteochondromas around the knee, forearm deformities, morphology and distribution of lesions, and correlations between these factors and genu valgus. The measurement of LDFA and MPTA was performed to identify the sources of genu valgus deformity. Based on the measurement of the mechanical axis, limbs were classified as genu valgus (n = 22) or normal mechanical axis groups (n = 90). The different severities of the genu valgus patients were classified by MAD. By bivariate logistic regression, genu valgus was significantly associated with more sessile and flared metaphyseal lesions. However, only the number of flared metaphyseal lesions had a significant influence on the severity of genu valgus. By analyzing the LDFA and MPTA, it was found that abnormalities of both proximal tibia and distal femur play important roles in genu valgus. Early detection of sessile and flared metaphyseal knee lesions in patients with HME can contribute to early intervention of genu valgus. Level of relevance: Level 2.

Hereditary multiple exostosis (HME) is an autosomal dominant skeletal disorder characterized by the development of multiple cartilage-covered tumors on the external surfaces of bones (osteochondromas). Most of HME cases result from heterozygous loss-of-function mutations in EXT1 or EXT2 gene.
Clinical examination was performed to diagnose the patients: Whole exome sequencing (WES) was used to identify pathogenic mutations in the proband, which is confirmed by Sanger sequencing and co-segregation analysis: qRT-PCR was performed to identify the mRNA expression level of EXT1 in patient peripheral blood samples: minigene splicing assay was performed to mimic the splicing process of EXT1 variants in vitro.
We evaluated the pathogenicity of EXT1 c.1056 + 1G > T in a Chinese family with HME. The clinical, phenotypic, and genetic characterization of patients in this family were described. The variant was detected by whole-exome sequencing (WES) and confirmed by Sanger sequencing. Sequencing of the RT-PCR products from the patient\'s blood sample identified a large deletion (94 nucleotides), which is the whole exome 2 of the EXT1 cDNA. Splicing assay indicated that the mutated minigene produced alternatively spliced transcripts, which cause a frameshift resulting in an early termination of protein expression.
Our study establishes the pathogenesis of the splicing mutation EXT1 c.1056 + 1G > T to HME and provides scientific foundation for accurate diagnosis and precise medical intervention for HME.

OBJECTIVE: Approximately 30% of patients with hereditary multiple osteochondromas (HMO) have forearm deformity and dysfunction. The aim of this retrospective study was to review our experience with the surgical treatment of children with HMO and Masada IIb forearm deformities.
METHODS: Data of eight children treated for HMO Masada IIb forearm deformity at our hospital between 2015 and 2019 were collected from the hospital records and retrospectively reviewed. All patients underwent ulnar lengthening by distraction osteogenesis using either the Orthofix or Ilizarov external fixator. Range of movements at the elbow and wrist joints, and forearm supination/pronation, before and after the operation were recorded. Radiographs were evaluated by the Fogel method, and wrist joint function by the Krimmer method.
RESULTS: Follow-up radiographs showed significant improvement in relative ulnar shortening after treatment (pre-operative 9.23 ± 5.21 mm; post-operative 0.33 ± 4.13 mm). Changes in radial articular angle (pre-operative 33.55° ± 3.88° to 32.78° ± 6.57°) and carpal slip (pre-operative 45.00% ± 19.09%; post-operative 43.13% ± 16.68%) were not significant. Elbow flexion and extension, wrist flexion and extension, ulnar and radial deviation at wrist, and forearm rotation were significantly improved after surgery. Wrist function was graded as excellent in seven patients and as good in one patient. One patient treated with the Ilizarov external fixator had poor radial head reduction.
CONCLUSIONS: Ulnar lengthening with distraction osteogenesis is an effective treatment for HMO Masada IIb deformities. The optimum site for ulnar osteotomy appears to be at the proximal one-third to one-fourth of the ulna.

UNASSIGNED: To discuss the mutational features and their relationships with disease in a family with hereditary multiple osteochondroma (HMO) from Guangxi Province (GXBB-1 family), China.
UNASSIGNED: Genomic DNA and total mRNA were extracted from peripheral blood cells of GXBB-1 family members. Whole elements of the EXT1gene and its transcript, including exons, introns, exon-intron boundaries, and coding sequence (CDS) clones, were amplified and sequenced. Allele-specific PCR was used to confirm the position and type of mutation.
UNASSIGNED: All patients from the GXBB-1 family harbored the cosegregating heterozygous c.1056+1G>A mutation located in EXT1at an exon-intron boundary. Another three single-nucleotide polymorphisms (SNPs) were also detected in the patients, including IVS2+1G>A in intron 2, c.1844 T>C [p.Pro (CCT) 614Pro (CCC)] in exon 3, and c.2534G>A [p.Glu (GAG) 844Glu (GAA)] in exon 9. The latter two SNPs were synonymous variations.
UNASSIGNED: The heterozygous c.1056+1G>A mutation cosegregated with the phenotype, indicating that it is a pathogenic mutation in the GXBB-1 family. This mutation is reported for the first time in Chinese HMO patients. IVS2+1G>A and c.2534G>A have no relationship with the occurrence of disease. However, c.1844 T>C and c.1056+1G>A are linked, and their interaction needs to be further studied. c.1844T>C is a new SNP that has not been reported internationally.