Investigating the role connective tissue fibroblasts play in the altered muscle anatomy associated with the limb abnormality, Radial Dysplasia

Radial dysplasia (RD) is a congenital upper limb birth defect that presents with changes to the upper limb anatomy, including a shortened or absent radius, bowed ulna, thumb malformations, a radially deviated hand and a range of muscle and tendon malformations, including absent or abnormally shaped muscle bundles. Current treatments to address wrist instability caused by a shortened or absent radius frequently require an initial soft tissue distraction intervention followed by a wrist stabilisation procedure. Following these surgical interventions, however, recurrence of the wrist deviation remains a common, long-term problem following treatment. The impact of the abnormal soft connective tissue (muscle and tendon) anatomy on the clinical presentation of RD and the complications following surgery are not understood. To address this, we have examined the muscle, fascia and the fascial irregular connective tissue (ICT) fibroblasts found within soft connective tissues, from RD patients. We show that ICT fibroblasts isolated from RD patients are functionally abnormal when compared to the same cells isolated from control patients and secrete a relatively disordered extracellular matrix (ECM). Furthermore, we show that ICT fibroblast dysfunction is a unifying feature found in RD patients, even when the RD clinical presentation is caused by distinct genetic syndromes.

Cardiomyopathy associated 5 (CMYA5) implicated as a genetic risk factor for radial hemimelia in Siamese cats

OBJECTIVES

The present study aimed to determine the inheritance pattern and genetic cause of congenital radial hemimelia (RH) in cats.

METHODS

Clinical and genetic analyses were conducted on a Siamese cat family (n = 18), including two siblings with RH. Radiographs were obtained for the affected kittens and echocardiograms of an affected kitten and sire. Whole genome sequencing was completed on the two cases and the parents. Genomic data were compared with the 99 Lives Cat Genome data set of 420 additional domestic cats with whole genome and whole exome sequencing data. Variants were considered as homozygous in the two cases of the siblings with RH and heterozygous in the parents. Candidate variants were genotyped by Sanger sequencing in the extended pedigree.

RESULTS

Radiographs of the female kitten revealed bilateral absence of the radii and bowing of the humeri, while the male kitten showed a dysplastic right radius. Echocardiography suggested the female kitten had restrictive cardiomyopathy with a positive left atrial-to-aortic root ratio (LA:Ao = 1.83 cm), whereas hypertrophic cardiomyopathy was more likely in the sire, showing diastolic dysfunction using tissue Doppler imaging (59.06 cm/s). Twenty-two DNA variants were unique and homozygous in the affected kittens and heterozygous in the parents. Seven variants clustered in one chromosomal region, including two frameshift variants in cardiomyopathy associated 5 (CMYA5) and five variants in junction mediating and regulatory protein, P53 cofactor (JMY ), including a missense and an in-frame deletion.

CONCLUSIONS AND RELEVANCE

The present study suggested an autosomal recessive mode of inheritance with variable expression for RH in the Siamese cat family. Candidate variants for the phenotype were identified, implicating their roles in bone development. These genes should be considered as potentially causal for other cats with RH. Siamese cat breeders should consider genetically testing their cats for these variants to prevent further dissemination of the suspected variants within the breed.

Thalidomide upper limb embryopathy - pathogenesis, past and present management and future considerations

This review article provides a comprehensive overview of thalidomide upper limb embryopathy including updates about its pathogenesis, a historical account of the management of the paediatric thalidomide patient, experience with management of the adult patient, as well as creating awareness about early onset age-related changes associated with limb differences. Despite its withdrawal from the market in November 1961, novel discoveries have meant thalidomide is licensed again and currently still in use to treat a variety of conditions, including inflammatory disorders and some cancers. Yet, if not used safely, thalidomide still has the potential to cause damage to the embryo. Recent work identifying thalidomide analogues that retain clinical benefits yet without the harmful effects are showing great promise. Understanding the problems thalidomide survivors face as they age can allow surgeons to support their unique healthcare issues and translate these principles of care to other congenital upper limb differences.

Index pollicization: an evolution of ideas and techniques from a paediatric orthopaedic institution

Pollicization has been a very successful procedure in the treatment of specific types of hypoplastic thumb. Although much has remained the same since early descriptions of the procedure in the 1800s and 1900s, refinements over the years have made it safer and more predictable. Over the years at our institution we have studied, modified and refined our incisions to produce a new thumb that is aesthetically pleasing with excellent function. We present our technique for pollicization along with pearls and pitfalls we have discovered.

Clinico-radiological evaluation and management of type II radial ray defect in a young female from rural India: case report

Radial Ray Defect (RRD) is a rare disorder, and the etiology of this disorder is still under discussion. RRD is associated with many medical conditions for which prenatal counselling is of paramount importance. Any association with the family history is still unknown. The patient is a 16-year-old female who came to the orthopaedic clinic complaining of tingling and weakness in the right forearm. On examination, there was a gross deformity in the right forearm with radial deviation of the hand. An X-ray revealed radial ray defect type-2. She previously had a history of perinatal infection during early childhood. Surgery was successfully achieved, and positive results were accomplished. Radial Ray Defect can be focal or associated with other clinical manifestations. The timing of antenatal ultrasound for detecting this musculoskeletal anomaly is crucial. When RRD is associated with other syndromes, counselling to the parents about the quality of life and morbidity comes into play. Treatment is primarily surgical.

Radial Longitudinal Deficiency: Severity Differences Between U.S. and Japanese Cohorts

PURPOSE

Radial longitudinal deficiency (RLD) presents on a spectrum of severity and associated diagnoses. The literature is limited in describing patient presentation without comparative data between countries. In a study comparing 2 cohorts of patients, 1 in the United States and 1 in Japan, we hypothesized that there would be a similar presentation of forearm deficiency severity, thumb hypoplasia severity, and associated syndromes between the 2 cohorts.

METHODS

Patients with RLD were identified via a comprehensive chart review at 2 pediatric hospital cohorts, 1 in the United States and 1 in Japan, capturing patients presenting over 15 years. We assessed RLD and thumb hypoplasia severity via a modified Bayne and Klug and modified Blauth classifications. The relationship between these 2 diagnoses and the presence of common medical conditions were evaluated and correlated.

RESULTS

A total of 194 Japanese patients with 290 involved extremities were compared with 107 U.S. patients with 174 involved extremities. The U.S. cohort had a significantly more severe RLD, and a higher rate of bilaterality (63% vs 50%, respectively). A total of 131 Japanese patients (68%) and 41 U.S. patients (38%) had associated medical syndromes/associations, most frequently vertebral abnormalities, anal atresia, cardiac abnormalities, tracheoesophageal fistula and/or esophageal atresia, renal agenesis and dysplasia, and limb defects (VACTERL; 46 Japanese, 14 U.S.), Holt-Oram (44 Japanese, 5 U.S.), and thrombocytopenia absent radius syndrome (0 Japanese, 12 U.S.). Correlation analysis showed that increased RLD severity was associated with increased thumb hypoplasia severity in both groups, with 95% of modified Bayne and Klug III, IV, or V patients having severely affected thumbs (type IIIb, IV, or V).

CONCLUSIONS

The U.S. patients had a more severe RLD and a higher rate of bilaterality. Japanese patients had a higher incidence of associated syndromes and radial polydactyly. Both cohorts showed that increased forearm severity was associated with more severe thumb hypoplasia.

TYPE OF STUDY/LEVEL OF EVIDENCE

Differential diagnosis/symptom prevalence study III.

Flexor Digitorum Superficialis Opposition Transfer for Augmenting Function in Types II and IIIA Thumb Hypoplasia

PURPOSE

To report the functional outcomes associated with the flexor digitorum superficialis (FDS) opposition transfer for types II and IIIA thumb hypoplasia and determine if there is any noteworthy difference in the outcome dependent on the pulley used.

METHODS

We included patients who underwent a ring FDS opposition transfer and had at least 2 years follow-up. The study group consisted of 36 patients with 40 treated thumbs. All patients underwent follow-up examination and standardized testing. Outcome functional measures were recorded using the Pediatric Outcomes Data Collection Instrument (PODCI). There were 9 type II and 31 type IIIA hypoplastic thumbs. All patients underwent a ring FDS opposition transfer and a 4-flap z-plasty for first web space deepening. The pulley for opposition was flexor carpi ulnaris in 19 and the transverse carpal ligament in 21. Thirty-six thumbs had ulnar collateral ligament reconstructions, with 5 of the 36 undergoing combined ulnar collateral ligament/radial collateral ligament stabilizations. Average follow-up was 7.6 years (range, 2-16 years).

RESULTS

Average postoperative Kapandji score was 8 (range, 4-10). Grip, lateral pinch, and tripod pinch strengths averaged 46%, 49%, and 48% of age- and sex-matched normal controls, respectively. There was no significant difference between surgical pulleys used. The Pediatric Outcomes Data Collection Instrument global was 91 (range, 53-100), and PODCI happiness was 87 (range, 15-100).

CONCLUSIONS

We found the ring FDS opposition transfer to be an effective method for providing opposition for both type II and IIIA thumb hypoplasia. At follow-up, excellent opposition function and PODCI scores were noted, with no difference related to the type of pulley used. Type II thumbs had significantly greater grip and pinch strengths when compared with type IIIA thumbs.

Soft tissue release and bilobed flap for severe radial longitudinal deficiency

PURPOSE

To report the hand position, range of motion, functional results, and radiographic outcomes associated with treating radial longitudinal deficiency with release of constricting or deforming soft tissue and resurfacing of the radial skin deficiency with a bilobed flap.

METHODS

We recalled and reviewed patients with at least a 3-year follow-up who had undergone soft-tissue release and coverage with a bilobed flap. The study group consisted of 16 patients and 18 wrists. All patients underwent follow-up examination and radiographs. Outcome measures using Pediatric Outcomes Data Collection Instrument (PODCI), Disabilities of the Arm, Shoulder, and Hand (DASH), and visual analogue scale (VAS) scores were recorded.

RESULTS

At a mean of 9.2 years follow-up, the average final resting wrist radial deviation angle was 64° compared with 88° preoperatively. The average active wrist flexion-extension arc was 73°. Average DASH score was 27 (range, 5-54). PODCI global was 88 (range, 75-97), PODCI happiness was 86 (range, 70-100), and VAS overall satisfaction (range, 0-10) was 1.2 (range, 0-8). At final follow-up, no physeal growth arrests were noted on radiographs, and no patients to date have required ulnocarpal arthrodesis.

CONCLUSIONS

Soft-tissue release and coverage with a bilobed flap should be considered in the treatment algorithm for patients with radial longitudinal deficiency. Outcome measures show that these patients maintain useful active motion, and along with their parents, are satisfied with both the appearance and function. Some recurrence of radial deviation was noted, which was similar to results previously reported following centralization/radialization procedures, although with a lower inherent risk of both physeal injury to the ulna and stiffness. In addition, potential future procedures are not compromised by this surgical approach.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Ulnar aplasia, dysplastic radius and preaxial oligodactyly: Rare longitudinal limb defect in a sporadic male child

Ulnar hypoplasia is a rare longitudinal limb deficiency in which the ulna shows various degrees of deficiency. The condition is normally associated with radial defects, and in severe cases there is a reduction of postaxial/ulnar digits. Ulnar deficiency is an integral part of several syndromic malformations like Weyer's oligodactyly syndrome, limb/pelvis hypoplasia/aplasia syndrome, and ulnar-mammary syndrome. Here, we report an isolated unilateral ulnar deficiency in a boy who was a product of a consanguineous marriage. The subject demonstrated mesomelic shortening of the left arm with reduced zeugopod and autopod, and preaxial absence of two fingers. Additional findings in the affected limb were severe flexion contracture at the elbow joint, reduced and narrow palm, hypoplastic digits, and clinodactyly. Roentgenographic study revealed rudimentary ulna, dysplastic and posteriorly dislocated radius, crowding of carpals, and complete absence of digit rays of the thumb and index finger. Despite this anomaly, the subject could manage his daily life activities well. We present detailed clinical features and differential diagnosis of this rare limb malformation.