1. Duchenne Muscular Dystrophy: Orthopaedic Management

2. Introduction DMD patients have weak bones, especially if on steroids – Require enough calcium and vitamin D DMD patients not on steroids have 90% chance of developing progressive scoliosis Daily steroid treatment reduces the risk of scoliosis, or at least delays its onset Steroids increase the risk of vertebral fracture

3. Spinal Care Should involve an experienced spinal surgeon Comprises – Monitoring for scoliosis – Support of spinal/pelvic symmetry and spinal extension by the wheelchair seating system – Monitoring for painful vertebral fractures, particularly in patients using steroids

4. Surveillance (1) Monitoring for scoliosis – Clinical observation while ambulatory; spinal X-ray only if scoliosis observed – Once non-ambulatory, clinical assessment for scoliosis is essential at each clinic visit Baseline spinal radiograph assessment should be done around the time of becoming wheelchair dependent, comprising – A sitting anteroposterior full-spine radiograph – A lateral projection film

5. Surveillance (2) Follow-up X-rays should be done at least annually if there is a problem. Anteroposterior spinal radiograph is warranted: – Annually for curves of less than 15-20° – every 6 months for curves of more than 20° Gaps of greater than one year risk missing a worsening of scoliosis After growth has stopped, X-rays are only needed if there is any change clinically

6. Prophylaxis Attention should be paid to posture at all times – Prevention of asymmetrical contractures in ambulant boys – Proper wheelchair seating system, supporting spinal and pelvic symmetry and spinal extension Spinal bracing is not appropriate to try to delay surgery but may be used if surgery cannot be done, or is not the chosen option.

7. Treatment (1) Spinal fusion – To straighten the spine – To prevent further worsening of deformity – To eliminate pain due to vertebral fracture with osteoperosis – To slow rate of respiratory decline Anterior spinal fusion is inappropriate in DMD

8. Treatment (2) Posterior spinal fusion indicated – when Cobb angle >20° – in ambulatory patients who are not on steroids and have yet to reach skeletal maturity Aim: preserve best posture for comfort and function With steroids, less risk of deterioration. – Surgery can be left until the Cobb angle > 40° Operation should be discussed between family and surgeon Attention required for safe anaesthesia

9. Bone Health Management Bone health important in all phases of DMD – Patients have weak bones, especially if on steroids Low bone mineral density and increased risk of fractures compared to general population Underlying factors for poor bone health – Decreased mobility – Muscle weakness – Steroid therapy

10. Bone Health: Interventions Possible interventions – Vitamin D: needed if genuine deficiency. Supplement should be considered in children – Calcium: intake is best in the diet. Supplements should be consider if this is inadequate, following advice of dietician – Bisphosphonates: IV bisphosphonates recommended for vertebral fractures Bone density may need assessment with blood tests, bone scans, and other X-rays. Further research required to establish best practice

11. Long Bone Fracture Management A broken bone can be a significant threat to the continued ability to walk – Surgery should be considered to allow regained mobility as soon as possible – If fracture occurs, ensure boy’s PT is notified If an ambulant boy breaks his leg, internal fixation required to resume walking and have best chance of maintaining ambulation In non-ambulant boys, a broken leg can be safely treated by splinting/casting. – Functional position of limb and possible development of contractures should be taken into account

12. References & Resources The Diagnosis and Management of Duchenne Muscular Dystrophy, Bushby K et al, Lancet Neurology 2010 9 (1) 77-93 & Lancet Neurology 2010 9 (2) 177-189 – Particularly references, p186-188 The Diagnosis and Management of Duchenne Muscular Dystrophy: A Guide for Families TREAT-NMD website: www.treat-nmd.euwww.treat-nmd.eu CARE-NMD website: www.care-nmd.euwww.care-nmd.eu