Scapular fixation in muscular dystrophy

Reaching higher: External scapula assistance can improve upper limb function in humans with irreversible scapula alata

Background

Scapular dyskinesis, i.e., the deviant mobility or function of the scapula, hampers upper limb function in daily life. A typical sign of scapular dyskinesis is a scapula alata—a protrusion of the shoulder blade during arm elevation. While some reversible causes of scapula alata can be treated with therapy, other, irreversible causes require invasive surgical interventions. When surgery is not an option, however, severe limitations arise as standard approaches for assisting the scapula in daily life do not exist. The aim of this study was to quantify functional improvements when external, i.e., non-invasive, scapula assistance is provided.

Methods

The study was designed as a randomized controlled crossover trial. Eight participants with a scapula alata due to muscular dystrophy performed arm elevations in shoulder flexion and abduction while unassisted (baseline), externally assisted by a trained therapist, and externally assisted by a novel, textile-based scapula orthosis.

Results

With therapist assistance, average arm elevation increased by 17.3° in flexion (p < 0.001, 95% confidence interval of the mean \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C{I}_{95\%}=\hspace{0.17em}\left[9.8^\circ , 24.9^\circ \right]$$\end{document}CI95%=9.8∘,24.9∘), and by 11.2° in abduction (p < 0.01, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C{I}_{95\%}=\left[4.7^\circ , 17.7^\circ \right]$$\end{document}CI95%=4.7∘,17.7∘), constituting the potential of external scapula assistance. With orthosis assistance, average arm elevation increased by 6.2° in flexion (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C{I}_{95\%}=\left[0.4^\circ ,11.9^\circ \right]$$\end{document}CI95%=0.4∘,11.9∘) and by 5.8° in abduction (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C{I}_{95\%}=\left[3.0^\circ ,8.5^\circ \right]$$\end{document}CI95%=3.0∘,8.5∘). Remarkably, in three participants, the orthosis was at least as effective as the therapist. Moreover, orthosis assistance reduced average perceived exertion by 1.25 points (Borg Scale) when elevating a filled bottle during a simulated daily living task.

Conclusion

These findings indicate a large potential for future advancements in orthotics. Already now, the textile-based scapula orthosis presented here is a feasible tool for leveraging the benefits of external scapula assistance when a therapist is unavailable, as encountered in daily life scenarios.

Trial Registration ClincalTrials.gov (ID NCT04154098). Registered: November 6th 2019, https://clinicaltrials.gov/ct2/show/NCT04154098?term=scapula+orthosis&draw=2&rank=1

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00926-z.

Effect of taping on scapular kinematics of patients with facioscapulohumeral muscular dystrophy

The aim of this study is to investigate the effects of scapular taping on scapular kinematics by three-dimensional electromagnetic system during shoulder elevation in facioscapulohumeral muscular dystrophy patients. A total of 11 patients with facioscapulohumeral muscular dystrophy were included in the study. Scapular anterior-posterior tilt, upward-downward rotation, and internal-external rotations were evaluated using the three-dimensional electromagnetic system during the elevation of the upper limbs in the scapular plane before and after kinesio taping. For maximum humerothoracic elevation, there were no differences between the patients before and after taping on both dominant (p = 0.72) and non-dominant sides (p = 0.64). For scapular internal rotation, upward rotation, and posterior tilt, there were no differences between patients before and after taping during humerothoracic elevation on both dominant and non-dominant sides (p > 0.05). These results showed us that the excessive and abnormal movements of the scapula observed during the humeral elevation in facioscapulohumeral muscular dystrophy patients cannot be supported with flexible methods like kinesio taping. Therefore, we recommend to evaluate the scapula position by applying flexible and rigid taping to the patients who can reach over 90^o in humerothoracic elevation in future studies.

Facioscapulohumeral Muscular Dystrophy: Update on Pathogenesis and Future Treatments

A reliable model of a disease pathomechanism is the first step to develop targeted treatment. In facioscapulohumeral muscular dystrophy (FSHD), the third most common muscular dystrophy, recent advances in understanding the complex genetics and epigenetics have led to the identification of a disease mechanism, moving the field towards targeted therapy development. FSHD is caused by expression of DUX4, a retrogene located on the D4Z4 macrosatellite repeat array on chromosome 4q35, a gene expressed in the germline but typically repressed in somatic tissue. DUX4 derepression results from opening of the chromatin structure either by contraction of the number of repeats (FSHD1) or by chromatin hypomethylation of the D4Z4 repeats resulting from mutations in SMCHD1, a gene involved in chromatin methylation (FSHD2). The resulting expression of DUX4, a transcriptional regulator, and its target genes is toxic to skeletal muscle. Efforts for targeted treatment currently focus on disrupting DUX4 expression or blocking 1 or more of several downstream effects of DUX4. This review article focuses on the underlying FSHD genetics, current understanding of the pathomechanism, and potential treatment strategies in FSHD. In addition, recent advances in the development of new clinical outcome measures as well as biomarkers, critical for the success of future clinical trials, are reviewed.

Facioscapulohumeral Muscular Dystrophy

PURPOSE OF REVIEW

This article describes the clinical characteristics, diagnosis, molecular pathogenesis, and treatment of facioscapulohumeral muscular dystrophy (FSHD).

RECENT FINDINGS

FSHD comprises two genetically distinct types that converge on a common downstream pathway of the expression of the toxic protein DUX4. Approximately 95% of patients have FSHD type 1 (FSHD1), in which loss of DNA repetitive elements (D4Z4 repeats) in the subtelomeric region of chromosome 4q causes decreased methylation and epigenetic derepression of DUX4, a gene contained within each D4Z4 repeat. FSHD type 2 (FSHD2) occurs through a deletion-independent mechanism but, similar to FSHD1, leads to decreased methylation and epigenetic derepression in the same region of chromosome 4q. Whereas FSHD1 is dominantly inherited, FSHD2 shows digenic inheritance, and about 80% of patients will have a mutation in the SMCHD1 gene. DUX4 lacks a polyadenylation signal, so both FSHD1 and FSHD2 only occur in the presence of permissive 4q polymorphisms, which provide a stabilizing polyadenylation sequence. FSHD is an epigenetic disease, and penetrance and severity are related to both the number of residual D4Z4 units and D4Z4 methylation.

SUMMARY

Recent consensus guidelines outline standards for care for FSHD, and identification of potential therapeutic targets have shifted emphasis in the research community toward drug development and clinical trial planning.

Unusual scapular winging - A case report

Scapular mobility has a central role in maintaining normal upper limb function. Scapular winging is characterized by a failure in the dynamic stabilization of the scapula against the thoracic wall resulting in a condition in which the medial border of the scapula is prominent. The following case describes a patient who was referred to physiotherapy due to abnormal scapular protrusion. The main findings of the physical examination showed weakness of the scapular stabilizers more prominent on the right side than of the left. Additionally, the physical examination demonstrated weakness of the abdominal muscles, hip adductors, and ankle dorsi-flexors, as well as some facial muscles. The electromyography results were inconclusive. Further examination led to clinical suspicion of Facioscapulohumeral Dystrophy (FSHD) as a diagnosis, which was confirmed by genetic testing. Facioscapulohumeral Dystrophy is characterized by symptoms related to motor function and in most cases becomes evident in patients in their 20s and 30s. The disease signs and symptoms are often identified in a clinical setting. Currently, there are no reports describing an effective treatment for the disease. However, physiotherapy, moderate physical exercise, counselling, and use of suitable aids and orthoses may help improve functionality and mobility. This case report aims to increase the awareness of musculoskeletal physiotherapists to this unique dystrophy, when encountering complex presentations with scapular winging.

Facioscapulohumeral distrophy and physiotherapy: a literary review

[Purpose] The purpose of this review was to critically evaluate the literature concerning the physiotherapy of facioscapulohumeral dystrophy, and to determine an effective protocol for physiotherapy treatments, which can be adapted to patient characteristics. [Methods] A bibliographic research was carried out of research papers held in the following databases: PUBMED, PEDRO, MEDLINE, EDS BASE INDEX. The inclusion criteria for acceptance of the studies to the review were randomized controlled trials (RCTs) concerning a sample no smaller than 10 people and a medium- or long-term report of the results achieved. [Results] Just six of the works satisfied the inclusion criteria, and just three of them were useful for the review. However, these studies were difficult to compare. [Conclusion] At present, there are few studies concerning facioscapulohumeral dystrophy in the literature, and the few that are available rule out the utility of the techniques used. Therefore, more RCTs of new treatment strategies are needed.

Facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a common type of adult muscular dystrophy and is divided into types 1 and 2 based on genetic mutation. Clinically, both FSHD types often show asymmetric and progressive muscle weakness affecting initially the face, shoulder, and arms followed by the distal then proximal lower extremities. Approximately 95% of patients, termed FSHD1, have a deletion of a key number of repetitive elements on chromosome 4q35. The remaining 5%, termed FSHD2, have no deletion on chromosome 4q35. Nevertheless, both types share a common downstream mechanism, making it possible for future disease-directed therapies to be effective for both FSHD types.

Thoracoscapular Fusion for Winging of the Scapula with Screw Fixation for Fascioscapulohumeral Dystrophy (Modified Copeland-Howard Procedure)

INTRODUCTION

This article describes our technique of thoracoscapular fusion with screw fixation for treatment of winging of the scapula in patients with fascioscapulohumeral dystrophy.

STEP 1 PREOPERATIVE EVALUATION

Perform the Horwitz test.

STEP 2 POSITION THE PATIENT AND MARK THE SKIN FOR THE OPERATION

With the patient on a Montreal mattress, position the arms in 90° to 110° of elevation in the scapular plane and approximately 90° of external rotation and mark the skin.

STEP 3 SURGICAL APPROACH

Make an incision along the medial scapular edge, incise the trapezius muscle, and detach the levator scapula, rhomboid major, and rhomboid minor muscles.

STEP 4 PREPARE THE SCAPULA

Do not decorticate the scapula to avoid weakening it.

STEP 5 SELECT AND PREPARE THE RIBS

Expose three or four ribs subperiosteally, from their superior border to avoid the neurovascular bundle.

STEP 6 DRILL THE SCAPULA AND RIBS

Drill the ribs with a McDonald dissector underneath them to prevent damage to the pleura.

STEP 7 HARVEST AND INTRODUCE BONE GRAFT OR USE BONE-GRAFT SUBSTITUTE AND CLOSE

Pack bone chips or bone-graft substitute between the ribs and the deep surface of the scapula.

STEP 8 POSTOPERATIVE IMMOBILIZATION AND REHABILITATION

An adjustable brace with the arm in 60° of abduction and 30° of forward flexion is worn for three months.

RESULTS

Between July 1997 and July 2010, a thoracoscapular fusion was performed in thirty-five shoulders of twenty-four patients with fascioscapulohumeral dystrophy15.IndicationsContraindicationsPitfalls & Challenges.

Multidisciplinary approach to the management of myopathies

PURPOSE OF REVIEW

Aside from some inflammatory myopathies and very few genetic disorders, there are no therapies that make most patients with myopathies stronger. Consequently, the management of these patients can be frustrating for patients and their families as well as the clinicians taking care of them. Treatment of these patients must involve a comprehensive approach focused on limiting the secondary effects of skeletal muscle weakness, managing comorbidities associated with specific diseases, and, most importantly, optimizing patients' functional abilities and quality of life in terms of their ability to accomplish activities of daily living. While the approach to each patient differs depending on their disease, certain common themes can be addressed in each patient. This review highlights an approach centered on four conceptual themes ("the Four S's"): Strength therapies, Supportive care, Symptomatic therapies, and pSychological support.

RECENT FINDINGS

Although relatively few well-designed studies have been done that highlight conservative management of patients with various myopathies, an emerging literature helps guide the clinician in certain key areas, especially in relation to cardiac and pulmonary management of these patients.

SUMMARY

While disease-altering therapies have proven elusive for many muscle diseases, a multimodal approach to the conservative and supportive care of these patients can markedly improve their quality of life. Pharmacologic treatment options for specific myopathies will not be addressed in this article but are covered elsewhere in this issue of CONTINUUM.

Facioscapulohumeral dystrophy and scapuloperoneal syndromes

Facioscapulohumeral dystrophy (FSHD) is the third most common muscular dystrophy. It is named for its characteristic involvement of the muscles of the face and upper arm. It is present worldwide, with a prevalence of around 4 per 100000 and an incidence of about 1 in 20000. Overall lifespan is not affected significantly. The scapuloperoneal syndrome is a rarer presentation that may cause some confusion. FSHD is an autosomal dominant condition. The molecular genetics of FSHD are complex, with current understanding focusing on epigenetic effects related to contraction-dependent (FSHD1) and contraction-independent (FSHD2) effects of a hypomethylated repeat sequence (D4Z4), in the presence of a specific 4qA161 phenotype. Molecular genetic diagnosis is available based on these findings, but with some complexities which may lead to false-negative results on routine laboratory investigation. No medication has been demonstrated to alter the clinical course of the disease significantly. A range of supportive measures may be applied. This chapter reviews the epidemiology, pathogenesis, genetics, clinical features, investigation, prognosis, and management of patients with FSHD and the scapuloperoneal syndrome.