GNE myopathy: A prospective natural history study of disease progression

Mutations in the glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase gene cause GNE myopathy, a mildly progressive autosomal recessive myopathy. We performed a prospective natural history study in 24 patients with GNE myopathy to select evaluation tools for use in upcoming clinical trials. Patient clinical conditions were evaluated at study entry and one-year follow-up. Of the 24 patients, eight (33.3%) completed a standard 6-min walk test without assistance. No cardiac events were observed. Summed manual muscle testing of 17 muscles, grip power, and percent force vital capacity (%FVC) were significantly reduced (p < 0.05), and scores for 6-min walk test and gross motor function measure were decreased (p < 0.1) after one year. The decrement in %FVC was significant among non-ambulant patients, whereas the decrement in grip power tended to be greater among ambulant patients. The 6-min walk test, gross motor function measure, manual muscle testing, grip power, and %FVC reflect annual changes and are thus considered good evaluation tools for clinical trials.     

Good radiological and functional results after intramedullary nailing of distal radius fractures

Abstract

To evaluate the results after fixation of distal radius fractures using Micronail® internal fixation, a prospective cohort study was performed, including displaced fractures of the distal radius (AO type A 2.2, A3.1, and A3.2). In total, 60 patients were included and 44 patients were available for 1-year follow-up (radiological and clinical examination) and 39 for 5-year follow-up (telephone interview). It was found that all fractures healed, with an average radial volar tilt of 2°, radial length of 11 mm, and a radial inclination of 22°. The functional result was excellent-to-good in 93% of the patients. Thirteen patients (30%) reported paraesthesia of the superficial branch of the radial nerve at the 1-year follow-up. In four patients the paraesthesia of the radial nerve was persistent. No other complications or reoperations were reported by the patients at the 5-year follow-up and only one implant had been removed. The study confirms that the Micronail® is a minimal invasive method that can provide a stable fixation of selected distal radius fractures and provide a good functional outcome with a very low need of implant removal after fracture healing with few complications related to the operation, the main complication being permanent damage to the radial nerve.     

GNE myopathy associated with congenital thrombocytopenia: A report of two siblings

GNE myopathy is an autosomal recessive muscular disorder caused by mutations in the gene encoding the key enzyme in sialic acid biosynthesis, UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE/MNK). Here, we report two siblings with myopathy with rimmed vacuoles and congenital thrombocytopenia who harbored two compound heterozygous GNE mutations, p.V603L and p.G739S. Thrombocytopenia, which is characterized by shortened platelet lifetime rather than ineffective thrombopoiesis, has been observed since infancy. We performed exome sequencing and array CGH to identify the underlying genetic etiology of thrombocytopenia. No pathogenic variants were detected among the known causative genes of recessively inherited thrombocytopenia; yet, candidate variants in two genes that followed an autosomal recessive mode of inheritance, including previously identified GNE mutations, were detected. Alternatively, it is possible that the decreased activity of GNE/MNK itself, which would lead to decreased sialic content in platelets, is associated with thrombocytopenia in these patients. Further investigations are required to clarify the association between GNE myopathy and the pathogenesis of thrombocytopenia.     

Transient retrograde interfragmentary compression technique in AO/OTA type 33-C distal femur fractures: A surgical technique and short-term radiographic follow up results

Surgical treatment of AO/OTA type 33-C fractures is a therapeutic challenge despite advances in surgical instruments and techniques. We introduce a novel surgical technique named transient retrograde interfragmentary compression (TRIC) to help intraarticular fragment reduction in AO/OTA type 33-C fracture. We inserted a partial threaded 7.0-cannulated screw with a washer along the transepicondylar axis from the medial femoral epicondyle during the articular block reduction process of AO/OTA type 33-C fractures to strengthen the compressive force between the condylar fragments and to enhance the handling of the articular block fragment in the alignmental correction stage. Following the provisional reduction and fixation using lateral distal femur locking compression plate, TRIC screw was removed. Fifteen AO/OTA type 33-C distal femoral intraarticular fractures of thirteen patients were surgically treated using the TRIC technique. We analyzed the radiographic result of the patients by measuring the horizontal gap and vertical step-off in the postoperative radiographs. Mean horizontal fracture gap was 0.34 mm and mean vertical step-off between bicondylar fragments was 0.63 mm. The median value of the horizontal fracture gap and vertical step off was 0 and 0.46 mm, respectively. Mean time to union in the bicondylar fracture fragment was 9 week. TRIC is considered to be a valuable surgical reduction technique in the treatment of the AO/OTA 33-C type fractures.