The pathogenesis of congenital radial head dislocation/subluxation

Radial nerve palsy in the newborn combined with congenital radial head dislocation: Case report and literature review

RATIONALE

Radial nerve palsy in the newborn and congenital radial head dislocation (CRHD) are both rare disorders, and early diagnosis is challenging. We reported a case of an infant with concurrent presence of these 2 diseases and provide a comprehensive review of the relevant literature. The purpose of the study is to share diagnostic and treatment experiences and provide potentially valuable insights.

PATIENT CONCERNS

A newborn has both radial nerve palsy and CRHD, characterized by limited wrist and fingers extension but normal flexion, normal shoulder and elbow movement on the affected side, characteristic skin lesions around the elbow, and an "audible click" at the radial head. The patient achieved significant improvement solely through physical therapy and observation.

DIAGNOSES

The patient was diagnosed with radial nerve palsy in the newborn combined with CRHD.

INTERVENTIONS

The patient received regular physical therapy including joint function training, low-frequency pulse electrical therapy, acupuncture, paraffin treatment, as well as overnight splint immobilization.

OUTCOMES

The child could actively extend the wrist to a neutral position and extend all fingers.

LESSONS

If a neonate exhibits limited extension in the wrist and fingers, but normal flexion, along with normal shoulder and elbow movement, and is accompanied by skin lesions around the elbow, there should be a high suspicion of radial nerve palsy in the newborn.

Mesenchyme-specific loss of Dot1L histone methyltransferase leads to skeletal dysplasia phenotype in mice

Chromatin modifying enzymes play essential roles in skeletal development and bone maintenance, and deregulation of epigenetic mechanisms can lead to skeletal growth and malformation disorders. Here, we report a novel skeletal dysplasia phenotype in mice with conditional loss of Disruptor of telomeric silencing 1-like (Dot1L) histone methyltransferase in limb mesenchymal progenitors and downstream descendants. Phenotypic characterizations of mice with Dot1L inactivation by Prrx1-Cre (Dot1L-cKO^Prrx1) revealed limb shortening, abnormal bone morphologies, and forelimb dislocations. Our in vivo and in vitro data support a crucial role for Dot1L in regulating growth plate chondrocyte proliferation and differentiation, extracellular matrix production, and secondary ossification center formation. Micro-computed tomography analysis of femurs revealed that partial loss of Dot1L expression is sufficient to impair trabecular bone formation and microarchitecture in young mice. Moreover, RNAseq analysis of Dot1L deficient chondrocytes implicated Dot1L in the regulation of key genes and pathways necessary to promote cell cycle regulation and skeletal growth. Collectively, our data show that early expression of Dot1L in limb mesenchyme provides essential regulatory control of endochondral bone morphology, growth, and stability.

Congenital Deformities of the Hands

Evaluation of the pediatric musculoskeletal system may be difficult because of differences between children and adults. As children mature, their physical structure approaches that of an adult. However, in the meantime, varying stages of ossification and developmental timelines may confuse the average clinician. Congenital abnormalities of the upper extremity are extremely numerous, but here we present 10 that often are seen in clinical practice. The article discusses the diagnosis, evaluation, treatment, and outcomes of each condition.

Double ulnar osteomy for the treatment of congenital radial head dislocation

OBJECTIVE

The aim of this study was to retrospectively evaluate the effects of our double osteotomy technique in the treatment of congenital radial head dislocation (CRHD).

METHODS

A total 14 children (14 elbows; 71.42% male; mean age: 9.31 ± 3.06 years) with CRHD who underwent double osteotomy of the proximal ulna between April 2010 and June 2015 were included in the study. The patients with CRHD were identified according to medical history, plain radiographs or magnetic resonance imagings. The outcomes were evaluated through comparison of the preoperative and postoperative motion range of elbow and Mayo Elbow Performance Score (MEPS).

RESULTS

After a follow-up of 13-35 months (22.29 ± 5.80), compared with pre-operation, the flexion (132.14 ± 3.23° vs 123.21 ± 7.75°, P = 0.003), extension (8.21 ± 4.21° vs 1.07 ± 3.50°, P = 0.003), and pronation of elbow (83.21 ± 4.21° vs 80.36 ± 4.14°, P = 0.011) improved significantly in all patients. Furthermore, the carrying angle was recovered to the normal level (5-15°) in all of these patients (18.57 ± 5.69° vs 8.21 ± 2.49°, P = 0.001). MEPS score was significantly increased postoperatively (96.79 ± 2.49 vs. 90.71 ± 1.82, P = 0.000), with the good outcome in CRHD patients.

CONCLUSION

The results of our study suggested that this double osteotomy on the proximal ulna might be an effective method for the treatment of CRHD.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Inclusion of joint laxity, recurrent patellar dislocation, and short distal ulnae as a feature of Van Den Ende-Gupta syndrome: a case report

Background

Van Den Ende-Gupta Syndrome (VDEGS) is an extremely rare autosomal recessive syndrome with less than 20 reported families (approximately 40 patients) in the worldwide literature.

Case presentation

We have assessed one consanguineous Saudi family with typical features of VDEGS. Two siblings were affected with almost identical features; including blepharophimosis, arachnodactyly, flexion contractures of the elbows, camptodactyly, slender ribs, hooked lateral clavicular ends, and bilateral radial head dislocations. Both patients had several unusual features; including joint laxity, flat feet, recurrent patellar dislocations, and bilateral short distal ulnae. Full sequencing of SCARF2 revealed a homozygous mutation c.773G > A (p. Cys258Tyr) in both affected children. The parents (both with no abnormalities) were heterozygous for the same mutation.

Conclusion

Joint laxity, recurrent patellar dislocations, and short distal ulnae should be included as part of the clinical spectrum of VDEGS.