Shoulder Girdle Muscles Research Articles

Autosomal recessive limb-girdle muscular dystrophies in the Czech Republic.

BackgroundAutosomal recessive limb-girdle muscular dystrophies (LGMD2) include a number of disorders with heterogeneous etiology that cause predominantly weakness and wasting of the shoulder and pelvic girdle muscles. In this study, we determined the frequency of LGMD subtypes within a cohort of Czech LGMD2 patients using mutational analysis of the CAPN3, FKRP, SGCA, and ANO5 genes.MethodsPCR-sequencing analysis; sequence capture and targeted resequencing.ResultsMutations of the CAPN3 gene are the most common cause of LGMD2, and mutations in this gene were identified in 71 patients in a set of 218 Czech probands with a suspicion of LGMD2. Totally, we detected 37 different mutations of which 12 have been described only in Czech LGMD2A patients. The mutation c.550delA is the most frequent among our LGMD2A probands and was detected in 47.1% of CAPN3 mutant alleles. The frequency of particular forms of LGMD2 was 32.6% for LGMD2A (71 probands), 4.1% for LGMD2I (9 probands), 2.8% for LGMD2D (6 probands), and 1.4% for LGMD2L (3 probands).Further, we present the first results of a new approach established in the Czech Republic for diagnosis of neuromuscular diseases: sequence capture and targeted resequencing. Using this approach, we identified patients with mutations in the DYSF and SGCB genes.ConclusionsWe characterised a cohort of Czech LGMD2 patients on the basis of mutation analysis of genes associated with the most common forms of LGMD2 in the European population and subsequently compared the occurrence of particular forms of LGMD2 among countries on the basis of our results and published studies.

Baraitser-Winter cerebrofrontofacial syndrome: delineation of the spectrum in 42 cases.

Baraitser-Winter, Fryns-Aftimos and cerebrofrontofacial syndrome types 1 and 3 have recently been associated with heterozygous gain-of-function mutations in one of the two ubiquitous cytoplasmic actin-encoding genes ACTB and ACTG1 that encode β- and γ-actins. We present detailed phenotypic descriptions and neuroimaging on 36 patients analyzed by our group and six cases from the literature with a molecularly proven actinopathy (9 ACTG1 and 33 ACTB). The major clinical anomalies are striking dysmorphic facial features with hypertelorism, broad nose with large tip and prominent root, congenital non-myopathic ptosis, ridged metopic suture and arched eyebrows. Iris or retinal coloboma is present in many cases, as is sensorineural deafness. Cleft lip and palate, hallux duplex, congenital heart defects and renal tract anomalies are seen in some cases. Microcephaly may develop with time. Nearly all patients with ACTG1 mutations, and around 60% of those with ACTB mutations have some degree of pachygyria with anteroposterior severity gradient, rarely lissencephaly or neuronal heterotopia. Reduction of shoulder girdle muscle bulk and progressive joint stiffness is common. Early muscular involvement, occasionally with congenital arthrogryposis, may be present. Progressive, severe dystonia was seen in one family. Intellectual disability and epilepsy are variable in severity and largely correlate with CNS anomalies. One patient developed acute lymphocytic leukemia, and another a cutaneous lymphoma, indicating that actinopathies may be cancer-predisposing disorders. Considering the multifaceted role of actins in cell physiology, we hypothesize that some clinical manifestations may be partially mutation specific. Baraitser-Winter cerebrofrontofacial syndrome is our suggested designation for this clinical entity.

Factors that influence functional outcome after total or subtotal scapulectomy: Japanese Musculoskeletal Oncology Group (JMOG) study.

BackgroundScapulectomy requires not only joint resection but also wide resection of the shoulder girdle muscles. Even the significance of reconstruction has not yet been determined because of the difficulties in comparing the different conditions. The purpose of this study was to investigate factors that influence functional outcomes after scapulectomy in a multicenter study.MethodsThis retrospective study comprised 48 patients who underwent total or subtotal scapulectomy and were followed for at least one year after surgery. Patients were registered at the Japanese Musculoskeletal Oncology Group affiliated hospitals. Soft tissue reconstruction for joint stabilization was performed when there was enough remaining tissue for reconstruction of the rotator cuff and tendons. In 23 cases, humeral suspension was performed. The average follow-up period was 61.9 months. Multivariate analysis was performed using the patient’s background to determine which factors influence the Enneking functional score or active range of motion.ResultsThe average functional score was 21.1 out of 30. Active shoulder range of motion was 42.7 degree in flexion, 39.7 degree in abduction, 49.6 degree of internal rotation and 16.8 degree of external rotation. The amount of remaining bone influenced functional outcome, which means that preserving the glenoid or the acromion lead to better function compared to total scapulectomy (p<0.01). Factors that influenced each functional measure include the amount of remaining bone, soft tissue reconstruction, the length of the resected humerus and nerve resection (p<0.05).ConclusionAlthough shoulder function was almost eliminated following total or subtotal scapulectomy, minimal resection of bone, and soft tissue reconstruction should lead to better function.

Limb-girdle muscular dystrophy in Brazilian children: clinical, histological and molecular characterization

Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of genetic muscular dystrophies, involving 16 autosomal recessive subtypes and eight autosomal dominant subtypes. Autosomal recessive dystrophy is far more common than autosomal dominant dystrophy, particularly in children. The clinical course in this group is characterized by progressive proximal weakness, initially in pelvic and after in shoulder-girdle musculature, varying from very mild to severe degree. Significant overlap of clinical phenotypes, with genetic and clinical heterogeneity, constitutes the rule for this group of diseases. Muscle biopsies are useful for histopathologic and immunolabeling studies, and DNA analysis is the gold standard to establish the specific form of muscular dystrophy. Objectives: The aim of this study was to characterize the clinical, histological and molecular aspects in children with LGMD who attend a big public neuromuscular centre in our country to determine the frequency of different forms. Method: Thirty seven patients were classified as LGMD and included in this analysis. The study period extended from 2009-2012. The female to male ratio was 3:1. The age of onset ranged from two to 13 years, mean 7,5 years. Onset in the first decade was seen in 90%. Results: The initial clinical signs included: frequent falls (22 cases), difficulty in climbing stairs (13 cases), walk on tip toes (2 cases), difficulty in rising from the floor (2 cases) and difficulty on walking (1 case). The serum CK levels were high in all cases. Among the 37 patients, 15 (40,5%) were classified as sarcoglycanopathies (LGMD2C-F), five (13,5%) as dysferlinopathy (LGMD2B), five (13,5%) as calpainopathy (LGMD2A). Mutations in LMNA gene (LGMD1B), FKRP gene (LGMDI) and caveolin gene (LGMD 1C) were identified in two (5,5%), two (5,5%) and one patient (2,5%), respectively. In seven of 37 cases (19%) it was impossible to determine specific diagnosis. Calf hypertrophy, scapular winging and scoliosis were the most characteristic signs in sarcoglycanopathies. In LGMD2I calf hypertrophy is also observed. Atrophy of posterior compartment of thighs is frequent in children with LGMD2B and could suggest the diagnosis. In LGMD2A winging of scapulae and contractures in Achilles tendons were important findings. Muscle biopsy showed a dystrophic pattern in all cases, more intense in sarcoglycanopathies and LGMD2I. Differently from adult’s patients, inflammation changes in dysferlinopaties were uncommon. Lobuled fibers were characteristic changes in calpainopathies in children. Conclusions: A definitive diagnosis among various subtypes of LGMD in children is challenging. Our series was a large study on LGMD in Brazilian children and showed high frequency of sarcoglycanopathies followed by LGMD2A, LGMD2B, LGMD2I, LGMD1B and LGMD1C.

A defect in the RNA-processing protein HNRPDL causes limb-girdle muscular dystrophy 1G (LGMD1G)

Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of genetically determined muscle disorders with a primary or predominant involvement of the pelvic or shoulder girdle musculature. More than 20 genes with autosomal recessive (LGMD2A to LGMD2Q) and autosomal dominant inheritance (LGMD1A to LGMD1H) have been mapped/identified to date. Mutations are known for six among the eight mapped autosomal dominant forms: LGMD1A (myotilin), LGMD1B (lamin A/C), LGMD1C (caveolin-3), LGMD1D (desmin), LGMD1E (DNAJB6), and more recently for LGMD1F (transportin-3). Our group previously mapped the LGMD1G gene at 4q21 in a Caucasian-Brazilian family. We now mapped a Uruguayan family with patients displaying a similar LGMD1G phenotype at the same locus. Whole genome sequencing identified, in both families, mutations in the HNRPDL gene. HNRPDL is a heterogeneous ribonucleoprotein family member, which participates in mRNA biogenesis and metabolism. Functional studies performed in S. cerevisiae showed that the loss of HRP1 (yeast orthologue) had pronounced effects on both protein levels and cell localizations, and yeast proteome revealed dramatic reorganization of proteins involved in RNA-processing pathways. In vivo analysis showed that hnrpdl is important for muscle development in zebrafish, causing a myopathic phenotype when knocked down. The present study presents a novel association between a muscular disorder and a RNA-related gene and reinforces the importance of RNA binding/processing proteins in muscle development and muscle disease. Understanding the role of these proteins in muscle might open new therapeutic approaches for muscular dystrophies.

Heterozygous D90A-SOD1 mutation in a patient with facial onset sensory motor neuronopathy (FOSMN) syndrome: a bridge to amyotrophic lateral sclerosis

ObjectiveTo describe a patient with facial onset sensory motor neuronopathy (FOSMN) syndrome associated with a heterozygous D90A mutation in superoxide dismutase (SOD1) gene.MethodsThe patient underwent neurological and neurophysiologic examinations, including...

Congenital Muscular Torticollis and Positional Plagiocephaly

Congenital Muscular Torticollis and Positional Plagiocephaly

Congenital Muscular Torticollis and Positional Plagiocephaly

On the basis of observational studies, child health practitioners in primary care settings should consider the diagnosis of congenital muscular torticollis (CMT)in infants with risk factors from birth history for intrauterine malpositioning or constraint (C). On the basis of observational studies, CMT is often associated with other conditions, including positional plagiocephaly and gross motor delays from weakened truncal muscles and/or lack of head control in early infancy (C). On the basis of observational studies, child health practitioners should counsel parents that infants should be on their stomachs frequently whenever they are awake and under direct adult supervision to develop their prone motor skills (C). On the basis of consensus, early identification of CMT(with or without positional plagiocephaly) and prompt referral to a physical therapist experienced in the treatment of CMT should be considered to avoid more costly or invasive treatments, such as cranial orthoses or surgery (D).

A man with small vessel vasculitis presenting with brachial diplegia, multiple cranial mononeuropathies and severe orthostatic hypotension in diabetes mellitus: a case report

IntroductionWe report a rare case of fulminant vasculitic mononeuropathy resulting in brachial diplegia, with suspected brainstem and autonomic nervous system involvement in a patient with diabetes mellitus.Case presentationA 58-year-old Hispanic Caucasian man with diabetes mellitus presented with a 1-year history of progressive bilateral upper extremity weakness, orthostatic intolerance and progressive memory decline. Diagnostic evaluation including laboratory tests for progressive encephalopathies, systemic inflammatory and non-inflammatory neuropathies, cerebrospinal fluid analyses, electrodiagnostic studies, and nerve biopsy were performed. Clinical examination revealed moderate cognitive deficits on the Montreal Cognitive Assessment scale, bilateral facial weakness and weakness of bilateral shoulder girdle and intrinsic hand muscles. Cerebrospinal fluid analyses revealed elevated protein and an elevated immunoglobulin G synthesis rate, suggesting an immune-mediated process. Further laboratory work up was non-diagnostic. Electrodiagnostic studies demonstrated chronic asymmetric axonal mononeuropathies with ongoing denervation. A superficial radial nerve biopsy showed a chronic vasculitic neuropathy. Glucocorticosteroid treatment, symptomatic pharmacologic and supportive non-pharmacologic therapies resulted in improved clinical outcomes despite challenges with glycemic control.ConclusionsThis case report emphasizes the importance of a thorough evaluation of atypical or uncommon neuromuscular presentations in diabetic patients without etiological presumptions. This is necessary in order to promptly establish a diagnosis, initiate appropriate therapies and prevent irreversible nerve injury.

Polymyalgia Rheumatica in Older Adults

Polymyalgia rheumatica (PMR) is the most common inflammatory rheumatic disease in the elderly. The incidence of PMR increases markedly with advancing age. It is characterized by abrupt-onset pain and stiffness of the shoulder and pelvic girdle muscles. There are several conditions that can mimic PMR, making the evaluation of PMR challenging. The majority of PMR is usually diagnosed in the primary care setting, but standard clinical investigations and referral pathways for suspected PMR are unclear. There are wide variations in the management of PMR. Additionally, the response to standardized therapy is heterogeneous and a significant number of patients fail to respond completely. There is also an overlap with inflammatory arthritis and large vessel vasculitis for which adjuvant disease-modifying medications are often used. Prolonged corticosteroid therapy is associated with a variety of side effects, particularly when high-dose glucocorticoid therapy is employed. Diagnosis and management of PMR requires a detailed knowledge of the disease, its differential diagnoses and the therapeutic options. The purpose of this article is to discuss the major clinical issues specific to the assessment and management of PMR in older adults.

Laparoscopic cholecystectomy under spinal anesthesia in a patient with limb-girdle muscular dystrophy

To the Editor, A 61-yr-old gentleman with longstanding muscular dystrophy presented with acute cholecystitis and sepsis. Three months later, with a biliary drainage tube still in place, he presented for semi-elective laparoscopic cholecystectomy. This patient kindly gave consent for publication of this report. The exact type of the patient’s muscular dystrophy was unclear despite extensive workup by his neurologist; however, his presentation was most in keeping with limbgirdle muscular dystrophy Type 2A. His symptoms began at age 14 yr when he developed proximal upper arm weakness and subsequent muscle wasting. By age 50 yr, he began to develop progressive weakness and wasting of his proximal lower limbs. He is now unable to climb out of bed or climb stairs easily. His echocardiogram was unremarkable and, surprisingly, so was the result of his preoperative spirometry test. Nevertheless, his respiratory therapist noted he was quite dyspneic at the end of the spirometry testing. Limb-girdle muscular dystrophy, a class of muscular dystrophy, is a heterogeneous group of neuromuscular diseases characterized by progressive muscle weakness and atrophy of the shoulder and/or hip girdle muscles. Cardiac involvement is rare. Respiratory involvement may be present in long-standing disease. Although laparoscopic cholecystectomy is generally performed with endotracheal intubation and positive pressure ventilation, we were concerned about the ability to wean this patient from the ventilator postoperatively. Laparoscopic cholecystectomy under spinal anesthesia has been described. Sinha et al. published a retrospective review of 3,492 laparoscopic cholecystectomy procedures under spinal anesthesia. Findings included a lower incidence of nausea and vomiting and decreased intravenous analgesic requirements. Abdominal muscle relaxation was not problematic. Shoulder and neck pain occurred in 12.3% of patients. Conversion to general anesthesia was required in 0.5% of cases. Given our concerns about the potential for problematic weaning from ventilation, a discussion took place between anesthesiology and general surgery about how best to proceed. We elected to offer this patient spinal anesthesia for his procedure. Complicating this choice was a significant language barrier. His daughter offered to join us intraoperatively for translation and emotional support. Her presence was invaluable. We performed a subarachnoid block at approximately the L3/4 level with a midline approach using a 25G pencilpoint spinal needle. This was performed in the right lateral position as the patient was unable to sit due to his muscle weakness. A T4-level block was achieved using 0.75% hyperbaric bupivacaine 21 mg (2.8 mL) and fentanyl 20 lg. The patient was placed in a supine, not Trendelenburg, position to achieve this block. Invasive blood pressure monitoring was used, and blood pressure was supported throughout the surgery with a phenylephrine infusion when required. The patient complained of diaphragmatic discomfort and right shoulder pain intermittently, which was managed using a remifentanil infusion of 0.05 0.15 lg kg min, shoulder massage, and reassurance from his daughter. The surgeon also sprayed the patient’s diaphragm with 1% M. C. Chuang, MD L. V. Duggan, MD (&) R. D. van Heest, MD W. MacLeod, MD Department of Anesthesiology and Perioperative Medicine, Royal Columbian Hospital, University of British Columbia, New Westminster, BC, Canada e-mail: laura.duggan@fraserhealth.ca; lauraduggan@yahoo.com

Brachial amyotrophic diplegia associated with a novel SOD1 mutation

Background: Brachial amyotrophic diplegia (BAD) is an adult-onset subtype of lower motor neuron disease mainly affecting men, largely restricted to proximal arm and shoulder girdle muscles without involvement of lower limbs or appearance of pyramidal signs. BAD is considered a sporadic disorder although a SOD1 mutation (L106P) was recently described in a patient with BAD.

Facioscapulohumeral muscular dystrophy and Charcot-Marie-Tooth neuropathy 1A - evidence for “double trouble” overlapping syndromes

BackgroundWe report on a patient with genetically confirmed overlapping diagnoses of CMT1A and FSHD. This case adds to the increasing number of unique patients presenting with atypical phenotypes, particularly in FSHD. Even if a mutation in one disease gene has been found, further genetic testing might be warranted in cases with unusual clinical presentation.Case presentationThe reported 53 years old male patient suffered from walking difficulties and foot deformities first noticed at age 20. Later on, he developed scapuloperoneal and truncal muscle weakness, along with atrophy of the intrinsic hand and foot muscles, pes cavus, claw toes and a distal symmetric hypoesthesia. Motor nerve conduction velocities were reduced to 20 m/s in the upper extremities, and not educible in the lower extremities, sensory nerve conduction velocities were not attainable. Electromyography showed both, myopathic and neurogenic changes. A muscle biopsy taken from the tibialis anterior muscle showed a mild myopathy with some neurogenic findings and hypertrophic type 1 fibers. Whole-body muscle MRI revealed severe changes in the lower leg muscles, tibialis anterior and gastrocnemius muscles were highly replaced by fatty tissue. Additionally, fatty degeneration of shoulder girdle and straight back muscles, and atrophy of dorsal upper leg muscles were seen. Taken together, the presenting features suggested both, a neuropathy and a myopathy. Patient’s family history suggested an autosomal dominant inheritance.Molecular testing revealed both, a hereditary motor and sensory neuropathy type 1A (HMSN1A, also called Charcot-Marie-Tooth neuropathy 1A, CMT1A) due to a PMP22 gene duplication and facioscapulohumeral muscular dystrophy (FSHD) due to a partial deletion of the D4Z4 locus (19 kb).ConclusionMolecular testing in hereditary neuromuscular disorders has led to the identification of an increasing number of atypical phenotypes. Nevertheless, finding the right diagnosis is crucial for the patient in order to obtain adequate medical care and appropriate genetic counseling, especially in the background of arising curative therapies.

P.16.2 The DUX4 promoter is expressed in FSHD-affected tissues

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder with a 1 in 7500 incidence. Symptoms typically arise in young adulthood and most patients show clinical features before age 30. FSHD is most commonly characterized by progressive wasting and weakness of facial and shoulder-girdle muscles, although no consistent pattern of penetrance or severity exists, even within affected families. A hallmark characteristic of FSHD is asymmetrical muscle weakness. There are also non-muscular features including retinal vasculopathy and high frequency hearing loss. Several recent breakthroughs now support a model in which mis-expression of the myotoxic DUX4 gene is a primary pathogenic event underlying FSHD. We hypothesized that there was a direct correlation between DUX4 expression patterns and the involvement of selected muscles (and ear and retinal pathologies) in FSHD. In short, we proposed that if DUX4 over-expression is indeed an underlying pathogenic event in FSHD, it must be preferentially expressed in FSHD-affected regions. To test this hypothesis, we developed transgenic reporter mice containing a putative DUX4 promoter cloned upstream of GFP. We generated three separate lines of DUX4 promoter-GFP mice. We found the DUX4 promoter directed GFP expression in the face and limbs of newborn and adult mice, as well as multiple cell types in the retina. Essentially all other organs were GFP negative with a few exceptions including the pancreas and brain (cerebellum, olfactory bulb, and hippocampus). Strikingly, all lines showed asymmetrical expression and variable penetrance in all GFP-positive tissues, even within individual litters. We conclude that our mice faithfully recapitulate expected DUX4 expression patterns in regions of FSHD pathology, and further suggest the role of DUX4 as pathogenic insult in FSHD. We are now using a modified but analogous system to inducibly express DUX4.

P.5.3 Whole body MRI study in 27 genetically confirmed Chilean patients with dysferlinopathy

To assess the natural course of dysferlinopathy, a cohort of 27 patients with genetically confirmed diagnosis underwent a whole body MRI scanning at distinct stages of disease. MRI scans were performed on a 1.5T Siemens equipment. Axial T1W and STIR images were obtained from the temporal regions to the ankles. Fatty replacement was ranked according to the scale of Kornblum et al. (2006). Two musculoskeletal radiologists, blinded to patients’ clinical and genetic data, analysed the images. Patients were separated into five groups according to years of disease course ( 17y n = 6). In general, MRI infiltration score correlated positively with disease duration (r = 0.53, p = 0.005) and negatively with global Muscle Functional Measure scale score (r = −0.70, p < .001). At early stages (i.e. <5 years group) grade 3–4 of fatty infiltration involved posterior compartments both legs and thighs as well as obturator externus, gluteus minimus and thigh adductors; lumbar erector spinae in the thoracoabdominal region, subscapularis on the shoulder girdle, along with relatively milder involvement of other muscle groups across the body. In the group of patients with a disease course from 9 to 12 years, fatty infiltration extended to the anterior compartments of legs and thighs, and progressed to the anterior compartment of the arm and forearm flexors. Interestingly, after 17 years of disease, masticatory and neck muscles, pectoralis minor, forearm extensors, transverse abdominal, piriformis and popliteus muscles were spared or showed mild compromise, while all the other muscles observed showed a grade 3–4 fatty replacement. Our results mainly agree with previous reports of MRI findings in lower limbs and their poor correlation with clinical phenotypes. Additionally we describe MRI findings in thoracoabdominal region, shoulder girdle and upper limb muscles from early to late stages of disease. FONDECYT#1110159 (Conicyt, Chile).

P.2.4 Upper extremity reachable workspace evaluation in DMD using Kinect

There is a lack of outcome measures evaluating upper extremity function in Duchenne Muscular Dystrophy (DMD) and a need to develop a quantitative low-cost method to evaluate upper extremity function in clinical trials. We developed a 3D reachable workspace tool to quantify joint mobility within the patient’s functional space. Reachable workspace is defined as all points relative to the torso an individual can reach by moving their hands, and its envelope is defined by the encompassing surface area. Reachable workspace is associated with functional upper limb status and is applicable in evaluating patients with DMD, where weakness and dysfunction stems from early involvement of shoulder girdle muscles. We developed a system based on the Microsoft Kinect to capture upper-limb movement during a specially devised workspace protocol. We are able to fit spherical surface data to the hand trajectory. The resulting envelope is quantified as a surface area using 3D surface plots projected to anatomical body planes. Surface area is normalized to the unit of the hemisphere of hand movement to facilitate comparison between individuals. We collected data in 8 pediatric subjects with DMD aged 6–13 years (mean: 9.4 ± 2.5 years). All subjects were able to follow the movement protocol for assessment of the reachable workspace. Average normalized surface area for the dominant side was 0.749 (SD: 0.063) with a minimal area of 0.627 obtained in an 11 year-old. Maximal area of 0.883 was obtained in another 11-year old subject with milder phenotype. Performance of the same movement protocol in a healthy control boy showed normalized surface area of 0.884, and in the adult control group ( n = 10), the average normalized surface area reached 0.679 (SD: 0.090). To increase the sensitivity to detect subtle weakness we measured the workspace with loading condition (500 g wrist weight). Further studies will examine reliability, accuracy and correlation with traditional functional outcome measures.

Medium to Long-Term Outcome of Thoracoscapular Arthrodesis with Screw Fixation for Facioscapulohumeral Muscular Dystrophy

Shoulder girdle muscle weakness is the most constant feature of facioscapulohumeral muscular dystrophy and leads to scapular winging. Mechanical fixation of the scapula to the thoracic wall provides a stable fulcrum on which the deltoid muscle can exert its action on the humerus. The aim of this study was to evaluate the medium to long-term outcome of thoracoscapular arthrodesis with screw fixation (the modified Howard-Copeland technique). All patients with facioscapulohumeral dystrophy who underwent thoracoscapular arthrodesis with screw fixation and bone-grafting from July 1997 to July 2010 were retrospectively reviewed. Preoperative and postoperative clinical assessment included active shoulder elevation, the Constant score, a patient satisfaction score, and cosmetic satisfaction. Union was determined both clinically and radiographically. Thoracoscapular arthrodesis was performed in thirty-five shoulders in twenty-four patients; eleven patients underwent bilateral procedures. The principal study group consisted of thirty-two shoulders in twenty-one patients with a minimum follow-up of twenty-four months (mean, eighty-eight months; range, twenty-four to 174 months). The mean Constant score increased from 30 (range, 17 to 41) preoperatively to 61 (range, 30 to 90) postoperatively. The mean satisfaction score increased from 1 (range, 0 to 4) to 8.4 (range, 4 to 10). Early complications consisted of one pneumothorax, one superficial wound infection, and four early failures, two of which were associated with noncompliance with the postoperative regimen. Late complications consisted of one posttraumatic fracture resulting in loosening and one painful nonunion; both were treated successfully with revision. Thoracoscapular arthrodesis with screw fixation prevented scapular winging and improved short-term and long-term shoulder function in patients with facioscapulohumeral dystrophy. Therapeutic level IV. See instructions for authors for a complete description of levels of evidence.

Clinical Presentation of Posterolateral Rotatory Instability of the Elbow in Children

Posterolateral rotatory instability is a type of ulnohumeral instability seen following elbow trauma. It is caused by a deficiency in the lateral collateral ligament complex that allows the radius and ulna to subluxate as a single unit with respect to the distal part of the humerus. There are few studies on this type of instability in children. Our purpose was to evaluate cases of posterolateral rotatory instability in children to better understand its presentation and manifestation as compared with those in adults. This was a retrospective chart review of patients from three academic centers. Eligible for inclusion were patients with a diagnosis of posterolateral rotatory instability who were treated with lateral ulnar collateral ligament reconstruction when they were less than nineteen years of age. Nine patients met the inclusion criteria. The mean age at the initial injury was ten years, and the average time from the initial injury to the final operation was 3.7 years. Six patients had prior elbow dislocation, and three had an isolated elbow fracture. Six of the nine patients had a forearm or elbow contracture. Only one patient had a positive pivot-shift test during the preoperative office examination, but all had a positive pivot-shift test when examined under anesthesia. Six had radiographic evidence of posterolateral rotatory instability. All patients underwent lateral ulnar collateral ligament reconstruction. At the time of follow-up, at a minimum of one year after the ligament reconstruction, there was no evidence of deformity secondary to early physeal closure and all elbows remained stable. Although posterolateral rotatory instability of the elbow is rare, it does exist in children. The instability may not always be recognized because of masking by contracture but, as is the case with adult patients, radiographs may show evidence of the instability. In children with contracture, the clinician should consider the possibility of a masked posterolateral rotatory instability and plan accordingly at the time of contracture release. Surgical correction is technically difficult, and traditional ligament reconstruction in skeletally immature patients may pose a risk to the lateral humeral condylar and epicondylar physes. Therapeutic level IV. See instructions for authors for a complete description of levels of evidence.

Does interhemispheric communication relate to the bilateral function of muscles? A study of scapulothoracic muscles using transcranial magnetic stimulation

Interhemispheric connections have been demonstrated between the motor cortex controlling muscle pairs. However, these investigations have tended to concentrate upon hand muscles. We have extended these investigations to proximal muscles that control the scapula upon the trunk and help to move and stabilise the shoulder. Using a paired pulse transcranial magnetic stimulation protocol, the interhemispheric interactions between different shoulder girdle muscle pairs, serratus anterior, upper trapezius and lower trapezius were investigated. Test motor evoked potentials were conditioned using conditioning pulse intensities of 80% and 120% of active motor threshold at three different condition-test intervals, during three different tasks. Interhemispheric inhibition was observed in upper trapezius using a conditioning intensity of 120% and condition-test interval of 8ms (17±18%, p<0.007). A trend towards inhibition was observed in lower trapezius and serratus anterior using a conditioning intensity of 120% and a condition-test interval of 8ms (13±22%; p<0.07 and 10±19% respectively; p<0.07). No interhemispheric facilitation was evoked. The study demonstrates that a low level of interhemispheric inhibition rather than interhemispheric facilitation could be evoked between these muscle pairs.

The influence of mental load on muscle tension

We examined the differences in muscle tension and in physiological measures depending on the type of mental task. Fifteen participants performed tests for sustained attention, vigilance and maintaining posture only. We analysed electromyogram (EMG) measures of extensor digitorum (ED), flexor carpi ulnaris (FU), deltoideus (DE) and trapezius (TR), and heart rate (HR) and respiratory frequency (RF). Measures indicated higher values for mental tasks than for maintained posture only with significant differences in all measures. The following relationships were also significant: between DE and physiological measures (HR and RF), between ED and the amplitude of EMG of the other three muscles, between FU and TR and between HR and RF. The results of this study showed that the relationship between mental demands and muscle tension was mostly reflected by tension in the arm and shoulder girdle muscles and, to a lesser degree, in forearm muscles. Practitioner Summary: We focused on physiological and muscle tension measures differentiating work according to the level of mental demands. Differences in sustained attention, vigilance and maintaining posture only proved that mental demands were mostly reflected by tension in arm and shoulder girdle muscles and, to a lesser degree, in forearm muscles.