Facioscapulohumeral Muscular Dystrophy (FSHD)

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Predicting the result before you commit to it

"Assess the deltoid" is only useful if you know how. The manoeuvre below does at the bedside exactly what the operation does surgically, so the arc achieved with the scapula held is a direct rehearsal of the arc the patient can expect afterwards - which makes it worth more than any imaging in the selection decision.

This is what "preserved deltoid" actually means in practice, and it is the single most useful part of the assessment - a patient who fails it should be counselled away from the operation regardless of how dramatic the winging looks.

What arthrodesis delivers - and what it does not

The operation is worth doing and the results are genuinely good, but the counselling has to be specific, because the trade is a real one.

• It does not make anything stronger. It converts existing deltoid power into useful motion by removing the wasted scapular excursion. No muscle is improved.
• It caps the arc. Scapulohumeral rhythm normally contributes roughly a third of elevation, and fusion deliberately abolishes the scapulothoracic component. The realistic endpoint is therefore useful function around or a little above shoulder height rather than full overhead elevation - in the best-documented bilateral series, active forward elevation improved from 62 to 102 degrees and abduction from 58 to 89.
• It does not alter the disease. FSHD continues to progress, and a deltoid that weakens later will erode the gain, which is an argument for operating while deltoid power is good rather than waiting until function is desperate.
• What it does do well is abolish the painful, prominent, cosmetically distressing winging and restore hand-to-face and hand-to-table function - in that same series the Subjective Shoulder Value rose from 25% to 72%, and every patient said they would recommend it.

The respiratory question, read honestly

The concern that fusing the scapula to the ribs splints the chest wall is theoretical but reasonable, particularly in a disease that itself causes restrictive impairment and when both sides are done. The best available data are reassuring - with bilateral, sequentially performed fusions there was no significant change in vital capacity - but two caveats belong with that reassurance. The series comprised five patients, which is far too small to exclude a clinically meaningful effect, and within it the forced vital capacity fell numerically from 86% to 77% of predicted. The practical position is therefore not "respiratory function is unaffected" but: obtain baseline pulmonary function tests, treat poor reserve as a genuine selection issue, stage the two sides rather than doing them together, and plan analgesia and chest physiotherapy that let the patient breathe deeply afterwards.

The shoulder dominates the exam, but it is not the whole of what an orthopaedic surgeon contributes.

• Foot drop from tibialis anterior weakness is managed with an ankle-foot orthosis. Tendon transfer is generally inappropriate: the donor is itself dystrophic and will weaken, so a transfer that works initially fails as the disease advances - the same logic that rules out tendon transfers around the scapula and sends those patients to fusion instead.
• Contractures, particularly of the Achilles tendon, are managed with stretching and orthoses, with surgical release reserved for a contracture that is genuinely blocking function.
• Lumbar hyperlordosis is characteristic and follows abdominal and paraspinal weakness; scoliosis occurs but is far less prominent than in the dystrophinopathies. Bracing is poorly tolerated where respiratory function is already reduced.
• Exercise is safe and beneficial, and this corrects older advice. Moderate aerobic activity and submaximal strength training improve function without accelerating muscle damage; what genuinely harms these patients is deconditioning and prolonged immobilisation, so post-operative and post-injury plans should minimise time immobilised.
• Anaesthesia: FSHD carries no established association with malignant hyperthermia, unlike some other myopathies, so it is not a reason to avoid volatile agents on that basis - but respiratory reserve, positioning and post-operative pulmonary care do require planning.