Results after treatment of congenital radioulnar synostosis: a systematic review and pooled data analysis

Imaging Assessment of the Pediatric Elbow: Developmental Variants and Common Pathologies

The pediatric elbow is a complex joint that undergoes rapid growth and development. The normal anatomy of the elbow varies depending on the age of the patient, which can be challenging for imaging interpretation. This article reviews developmental variants and common pathologies of the pediatric elbow, with a focus on their radiologic features. Normal anatomy and development of the pediatric elbow are discussed, including the six ossification centers and elbow alignment. Congenital anomalies such as longitudinal deficiencies of the upper extremity are reviewed. Some common injuries that affect the elbow, such as supracondylar fracture, lateral condyle fracture, medial epicondyle avulsion, and radial head dislocation are also described.

Fracture of the two forearm bones and congenital radioulnar synostosis: A case report and review of literature

Congenital proximal radioulnar synostosis limits prono-supination and is often well tolerated. Only one publication in the literature describes a fracture associated with this malformation. We report a case of radius and ulna shaft fractures in a 35-year-old patient with well-tolerated bilateral proximal congenital proximal radioulnar synostosis.

One-Bone Forearm Procedure for Severe Recalcitrant Forearm Deformities in Masada IIb Hereditary Multiple Exostoses

Introduction

Hereditary multiple exostoses (HME) Masada IIB has traditionally been treated by gradual ulnar lengthening with questionable efficacy in reducing the dislocated head. One-bone forearm (OBF) has been used as a reconstructive procedure in forearm deformities with very scarce literature for HME. The study aims to report short-term results of OBF as a definitive procedure for severe forearm deformities in Masada IIB patients with respect to clinical and radiological parameters.

Materials and Methods

Four patients with HME Masada IIb were included in this retrospective study. All patients complained of forearm and wrist deformity with an abnormal bony protrusion restricting elbow motion. Indications for OBF were ulnar shortening > 3 cm, dysplastic proximal radius with convex radial head and restricted prono-supination. All patients were examined pre-operatively and post-operatively clinically and radiographically using the Peterson's outcome score.

Results

The average age was 13 years (12-14 years). Pre-operative ulnar shortening, carpal slip percentage, and radial articular angle was 3.4 cm, 79.5%, and 47.5°, respectively. All radial heads were dislocated with convex articular surface restricting elbow extension and forearm prono-supination. At the latest follow-up, the mean elbow flexion was 110° with forearm in 10° supination. The mean carpal slip percentage, radial articular angle, and Peterson functional grade was 15%, 22.5°, and 8 points, respectively. The mean follow-up period was 30.25 months with no recurrence.

Conclusion

We recommend one bone forearm as a definitive procedure in HME Masada IIB patients with severe forearm deformities with ulnar shortening > 3 cm and dysplastic proximal radius with a dislocated radial head, for faster return to function.

Congenital Radioulnar Synostosis: A Case Report and Review of Various Osteotomies

Introduction

Congenital radioulnar synostosis is a rare deformity of the forearm characterized by a malformation of the proximal aspect of the radius and ulna. Various modalities of treatment options available include observation, excision of the synostosis and placing an interposition material, or performing derotation osteotomy. Several types of osteotomies at different forearm levels have been described in the literature.

Case Report

A 5-year-old female presented with bilateral congenital radioulnar synostosis which was treated with percutaneous corrective osteotomy and Joshi's external stabilizing system fixator application.

Conclusion

We describe the management of congenital radioulnar synostosis in a 5-year-old female child using a novel minimally invasive, single-staged procedure . This innovative technique provided the patient with a good functional outcome and she could return to her daily activities with a satisfactory range of motion.

Congenital Proximal Radioulnar Synostosis in an Elite Athlete–Case Report

Background and Objectives: Proximal radioulnar synostosis (PRUS) is the most frequent congenital forearm disorder, although the prevalence in the general population is rare with a few hundred cases reported. Pfeiffer, Poland, Holt–Oram, and other serious congenital syndromes contain this abnormality. Non-syndromic cases with isolated PRUS very often exhibit as SMAD6, NOG genes variants, or sex chromosome aneuploidy. A subgroup of patients with haematological abnormalities presents with HOXA11 or MECOM genes variants. Case report: We present a non-syndromic adult elite ice-hockey player with unilateral proximal radioulnar synostosis of the left forearm. In early childhood he was able to handle the hockey stick only as a right-handed player and the diagnosis was set later at the age of 8 years due to lack of supination. Cleary–Omer Type III PRUS was found on x-ray with radial head hypoplasia and mild osteophytic degenerative changes of humeroulnar joint. Since the condition had minimal impact on sports activities, surgical intervention was not considered. The player continued his ice-hockey career at the top level and joined a national team for top tournaments. Upper extremity function assessment with questionnaires and physical testing resulted in minimal impairment. The most compromised tool was the Failla score with 10 points from a total of 15. Genetic testing with Sanger sequencing revealed no significant pathogenic variant in SMAD6, NOG, and GDP5 genes. No potentially pathogenic copy number variants were detected by array-based comparative genomic hybridization. Conclusions: In the reported case, the ability of an athlete to deal with an anatomic variant limiting the forearm supination is demonstrated. Nowadays, a comprehensive approach to rule out more complex musculoskeletal impairment and family burden is made possible by evolving genetics.

The relation between radiographic manifestation and clinical characteristics of congenital radioulnar synostosis in children: A retrospective study from multiple centers

Objective

To review the radiographic manifestation and clinical appearance of children with congenital radioulnar synostosis (CRUS) retrospectively.

Study design

Retrospective cohort study of children with CRUS from multiple medical centers.

Results

A total of 329 patients (male 259, female 70) with an average age of 5.4 years (0.5-16 years old), were included in this study. In particular, 145 patients (145/329, 44.1%) demonstrated bilateral involvement, and 184 patients (left 123, right 61) demonstrated unilateral involvement. As for Clear and Omery (C&O) classification, most patients belonged to Type III, and then followed by Type IV. As for Chinese Multi-center Pediatric Orthopedic Study Group (CMPOS) classification, most patients belonged to Type III, and then followed by Type II and Type I. In C&O Type III, 92.03% patients demonstrated severe pronation. According to CMPOS classification, 92.98% Type I patients demonstrated neutral to mild pronation, 72.17% Type II patients demonstrated moderate pronation, and 92.03% Type III patients demonstrated severe pronation. The age distribution showed no significant difference between C&O Type II and IV (P = 0.96); the pronation ankylosis severity showed no significant difference between C&O Type II and IV (P = 0.387).

Conclusion

Although CRUS is a rare forearm deformity, there are certain relation between radiographic manifestation and clinical forearm functional restriction. CRUS patients of C&O or CMPOS Type III classification might suffer severe pronation deformity and warrant early intervention.

Rotational osteotomy with single incision and elastic fixation for congenital radioulnar synostosis in children: a retrospective cohort study

BACKGROUND

Derotational osteotomy remains the most commonly performed procedure in patients with congenital radioulnar synostosis (CRUS). Bone fixation is mostly performed using K-wires or plates. Many scars, loss of correction and neurovascular complications in the form were the most common complications across the studies. This report introduces a novel, minimally-invasive surgical approach, and reviews our experience.

METHODS

Twenty-seven children with CRUS were treated using the new technique, including bilateral forearms in 12 cases and unilateral forearm in 15 cases. A transverse osteotomy was performed at the ulnar and radial fusion site, the forearm was derotated osteotomy to the target position, intramedullary nailing was performed, and the elbow was flexed 90 degrees with a long-arm cast after surgery. One week after surgery, the forearm swelling disappeared, the long-arm cast was replaced, the elbow flexed at 90 degrees, and the forearm fixed in the maximum supination position for 4 weeks. Pre- and post-operative positions of the forearm were recorded; the pre- and post-operative activities of daily living (ADL) item scores were recorded for each patient.

RESULTS

All patients were followed up postoperatively for a mean duration of 20.7 months. The mean initial pronation deformity was 59.7±12.20 (40 to 100) degrees. The mean correction achieved was 51.2±14.50 degrees, resulting in a mean final position of 8.59±8.10 degrees of supination. The fixed angles of forearm pronation after surgery were corrected to 0-20°, with a mean of 8.33º [standard deviation (SD) 7.98°), and the difference was statistically significant compared with that before surgery (P<0.01). The patients' pre- and post-operative ADL item scores were 3.6 and 4.5, respectively, which was a 0.9-point change and was statistically significant (P<0.01). After surgery, 26 patients obtained good healing, and only one patient had delayed union, which was healed with forearm immobilization for a further month.

CONCLUSIONS

Rotational osteotomy with single incision and elastic fixation for CRUS in children is a simple operation, and provides advantages including small trauma, fewer postoperative complications, and good efficacy.

MECOM-related disorder: Radioulnar synostosis without hematological aberration due to unique variants

PURPOSE

The etiology for a considerable proportion of patients with congenital radioulnar synostosis (RUS) remains unclear. This study aimed to investigate the genetic cause of RUS without a known cause.

METHODS

Patients with RUS were investigated. Exome sequencing and/or Sanger sequencing was performed. Bioinformatics analysis was also performed. Pathogenicity was evaluated for variants of interest.

RESULTS

We identified unique missense variants in MECOM (encodes EVI1) associated with RUS in 8 families. Of them, 6 families had variants in residue R781, including 3 families with R781C (c.2341C>T), 2 families with R781H (c.2342G>A), and 1 family with R781L (c.2342G>T). Another 2 variants included I783T (c.2348T>C) in 1 family and Q777E (c.2329C>G) in 1 family. All these variants were clustered within the ninth zinc finger motif of EVI1. Phenotype evaluation identified that most of these patients with RUS harboring mutant MECOM had finger malformations, but none of them had identifiable hematological abnormalities. Functional experiments showed that MECOM R781C led to alterations in TGF-β-mediated transcriptional responses.

CONCLUSION

This study examined MECOM variants by focusing on RUS instead of hematological abnormalities. The R781 residue in EVI1 is a hotspot for human RUS variants. Mutant MECOM is the second most common cause for familial RUS.

Derotational Osteotomy and Plate Fixation of the Radius and Ulna for the Treatment of Congenital Proximal Radioulnar Synostosis

Purpose

To evaluate the clinical outcomes of derotational osteotomy followed by plate fixation at the radius and ulna for the treatment of congenital proximal radioulnar synostosis.

Methods

A total of 10 eligible patients (12 forearms) with congenital proximal radioulnar synostosis were admitted to our institution from January 2013 to January 2016 and treated by radioulnar derotational osteotomy followed by plate fixation. There were 5 males and 5 females with an average age of 5.4 ± 2.0 (3–9) years old. The average forearm position was 56.67 ± 14.36° (range, 40°–80° pronation) in pronation before surgery. According to the classification system of Cleary and Omer, 3 forearms were categorized as type II, 7 as type III, and 2 as type IV. The pre- and postoperative forearm function was recorded and evaluated by the Failla scoring system.

Results

All included patients were successfully followed up for an average time of 73.90 ± 8.24 months (range, 61–84 months). The mean achieved correction of the forearm was 53.33° ± 12.67° (range, 35°–70°). The average final position was 3.33° ± 14.98° (range, 20° of supination to 25° of pronation) in pronation. Bony union was achieved in a mean of 10.38 ± 1.25 weeks (range, 8.4–12.3 weeks) with no loss of correction. There were no incidences of nonunion, osteomyelitis, or neurologic or circulatory complications. The preoperative functional results were good in 1 forearm, fair in 8 forearms and poor in 3 forearms. In terms of final follow-up functional evaluations, 3 forearms were excellent, 6 forearms were good, and 3 forearms were fair.

Conclusions

Congenital proximal radioulnar synostosis can be successfully treated using derotational osteotomy and plate fixation of the radius and ulna, which is an effective method with fewer postoperative complications and expected clinical outcomes.

Corrective derotation osteotomies to treat congenital radioulnar synostosis in children: results of a systematic review and meta-analysis

BACKGROUND

The primary objective of this review is to estimate the rotational correction after corrective derotation osteotomies (CDO) for congenital radioulnar synostosis (CRUS). The secondary objective of this review is to identify the complications with CDO in CRUS.

METHODS

We included studies in the English literature from electronic bibliographic databases Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, Directory of Open access journals (DOAJ), EMBASE, MEDLINE, ProQuest, PubMed, and Scopus up to December 2020 that determined the effects of CDO in CRUS for two or more cases with a mean follow-up of 1 year or more. We used the National Institutes of health quality assessment tool for case series (interventional) and Modified Coleman methodology Score for assessment of risk of bias in the included studies.

RESULTS

We pooled 383 forearms (318 participants) from 23 studies with mean age of 6.28 ± 1.75 years. The mean pronation deformity was 72.83 ± 15.64° from 22 studies. The CDO derotated forearm to 10.4 ± 5.90° of mean pronation in 12 studies and 13.47 ± 9.51° of mean supination in nine studies. One study corrected the forearms to a neutral position. The mean derotation from CDO was 73.13 ± 16.54° (35° supination to 130° pronation). The overall mean difference was - 68.26° [95% CI - 86.87, - 49.66] of correction favoring supination. There were eight transient nerve palsies and six compartment syndromes from synostosis site osteotomies (four studies).

DISCUSSION

We had poor-quality studies at a high risk of bias on the described tools of assessment. We could estimate the directional effect of CDO in CRUS favoring correction from pronation to supination; however, due to the heterogeneity among studies, we cannot comment on the most efficient and least harmful CDO techniques. The single bone osteotomies seem to be efficient, simple, and reportedly low on complications but need evaluation. We cannot define the indications for correction and expected improvement in functional outcomes from osteotomy techniques.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00582-4.