summary Facioscapulohumeral Muscular Dystrophy is a common congenital neuromuscular disorder which causes progressive muscle weakness in the face, shoulder girdle, and upper arm. Diagnosis is made clinically with presence of a combination of scapular winging with limited arm abduction, incomplete eye closure, transverse smile, absence of eye and forehead wrinkles, with selective sparing of deltoid, distal part of pectoralis major, and erector spinae muscles. Treatment is usually physical and occupational therapy. Operative scapulothoracic fusion is indicated for scapular winging associated with progressive pain. Epidemiology Incidence third most common muscular dystrophy after Duchenne and myotonic dystrophy 1 in 14,000 births Prevalence 2 to 7 per 100,000 individuals Demographics male = female males more severely affected 95% present prior age of 20 Etiology Genetics inheritance pattern autosomal dominant (majority) up to 30% of mutations can be spontaneous mutation deletion of repeated elements of D4Z4 on chromosome 4q35 double homeobox 4 (DUX4) no longer supressed believed to cause disease through gain-of-function mechanism Associated Conditions orthopaedic manifestations scoliosis (rare) camptocormia (bent spine syndrome) Classification Type 1A (FSHD1A) most common form also referred to as chromosome 4 linked Type 1B (FSHD1B) rare also referred to as non-chromosome 4 linked Infantile more severe subtype of Type 1A and 1B and symptoms present earlier (~ 5 years old) most patients become wheelchair bound during the 2nd decade of life marked lumbar lordosis is progressive and is pathognomonic for infantile FSHD hearing loss, vision problems and seizures have been documented have severely compromised pulmonary function and succumb in early adolescence Presentation Symptoms slow muscular weakness over time Physical Exam inspection scapular winging with limited arm abduction causing prominent shoulder blades incomplete eye closure transverse smile absence of eye and forehead wrinkles selective sparing of deltoid, distal part of pectoralis major, and erector spinae muscles motion marked decrease in shoulder flexion and abduction Imaging Radiographs do not play an important role in evaluation or treatment Studies Labs CPK levels usually normal Electrodiagnostic EMG usually shows nonspecific myopathic changes with fibrillations Muscle Biopsy nonspecific chronic myopathic changes performed only in those individuals in whom FSHD is suspected but not confirmed by molecular genetic testing Genetic Testing 95% sensitive and highly specific for FSHD Pulmonary Function Testing baseline testing at diagnosis once disease has progressed to include proximal lower extremities PFTs should be done yearly Treatment Nonoperative PT/OT, speech therapy indications shoulder girdle and upper arm weakness to maintain strength and range of motion of affected muscles outcomes although their arms become gradually weaker from adolescence on, patients can usually work into later life Operative scapulothoracic fusion indications scapular winging technique wiring of the medial border of the scapula to ribs three through seven internal fixation is achieved with 16-gauge wire wires ensure firm fixation and eliminate the need for postoperative immobilization and subsequent rehabilitation child uses a sling for 3 to 4 days postoperatively, and then begins a physical therapy program outcomes increased active abduction and forward flexion of the shoulder, and improved function as well as cosmesis Complications The following complications have been reported following scapulothoracic fusion: Infection Pneumothorax Nonunion Failure of Fixation Prognosis Insidious disease course ~ 20% of patients > 50 years or older require a wheelchair Life expectancy is NOT shortened