Orthopedic care is an important aspect of the overall management of patients with Duchenne muscular dystrophy (DMD). In addition to progressive muscle weakness and loss of function, patients may develop joint contractures, scoliosis, and osteoporosis, causing fractures; all of these necessitate intervention by a multidisciplinary team including an orthopedic surgeon as well as rehabilitation specialists such as physio- and occupational therapists. The causes of these musculoskeletal complications are multifactorial and are related to primary effects on the muscles from the disease itself, secondary effects from weak muscles, and the related side effects of treatments, such as glucocorticoid use that affect bone strength. The musculoskeletal manifestations of DMD change over time as the disease progresses, and therefore, musculoskeletal management needs change throughout the life span of an individual with DMD. In this review, we target pediatricians, neurologists, orthopedic surgeons, rehabilitation physicians, anesthesiologists, and other individuals involved in the management of patients with DMD by providing specific recommendations to guide clinical practice related to orthopedic issues and surgical management in this setting.
- DMD —
- Duchenne muscular dystrophy
- FVC —
- forced vital capacity
Duchenne muscular dystrophy (DMD) has common and predictable musculoskeletal manifestations. In addition to progressive muscle weakness and loss of function, patients may develop joint contractures, scoliosis, and fractures due to osteoporosis. The causes of these musculoskeletal complications are multifactorial and are related to primary effects on the muscles from the disease itself, secondary effects from weak muscles, and the adverse skeletal effects of glucocorticoids on bone strength. Because musculoskeletal manifestations of DMD change over time, management needs change throughout the life span.
Musculoskeletal management of the patient with DMD aims to preserve motor function for as long as possible, promote bone health, minimize the occurrence of joint contractures, and maintain a straight spine. A progressive approach to monitoring and interventions is recommended, with the overall goal of both nonsurgical and surgical interventions being focused on maximizing function and ensuring comfort.
An interdisciplinary team should be involved in assessing and treating musculoskeletal complications of DMD. This team may include a neurologist, an orthopedic surgeon, physical and occupational therapists, a rehabilitation physician, and a social worker. A pulmonologist and a cardiologist should be included in the team when surgical interventions are recommended. Endocrinologists or osteoporosis specialists often are responsible for bone health issues, a topic beyond the scope of this article except for a discussion on the management of acute fractures. Focused musculoskeletal evaluations should begin at the time of diagnosis and continue at least twice per year. Experienced clinicians can monitor the musculoskeletal system using history and physical examination, timed motor performance tests, observational or video recordings of gait, and diagnostic tests, such as spine radiographs for monitoring for scoliosis and vertebral fracture detection. Beyond the 2010 DMD Care Considerations,1,2 no existing guidelines specifically address musculoskeletal management in patients with DMD.
In the 2018 DMD Care Considerations, sponsored by the Centers for Disease Control and Prevention,3 authors seek to reinforce the 2010 recommendations2 related to using orthoses and surgical management of joint contractures and scoliosis. However, in this revision, authors emphasize some of the changing patterns observed over the past several years in each of these areas. Although the incidence of scoliosis has decreased dramatically in those treated with glucocorticoids (from 90% to ∼30%), the long-term impact of glucocorticoid treatment on the late development of scoliosis is unknown; long-term monitoring is thereby required.4,5 Additionally, in the 2018 Care Considerations, authors place a greater emphasis on the identification and management of a child with both long bone and vertebral fractures as well as identification of risk factors for osteoporosis. More details on these issues are provided in the Bone Health and Osteoporosis Management article that is part of this supplement.6,7 For an overview of the 2018 Orthopedic Care Considerations, see Fig 1.
Specific Core Recommendations
Contracture, spine, and fracture management are important facets of orthopedic treatment in DMD. Each is discussed below, and the issues to consider in the surgical management of patients with DMD are reviewed in Fig 2.
Contracture Management: Stretching and Orthoses
The current recommendation for a proactive approach to contracture management should continue to be followed. However, families should be involved with how this is prioritized among other treatment recommendations because the evidence for and against this treatment is limited. For a comprehensive discussion of stretching and the use of orthoses to prevent contractures, refer to the “Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy” article as part of this supplement.8
Contracture Management: Surgical Intervention
Many of the studies on surgical interventions to prevent limb contractures included in the 2010 Care Considerations were performed before the acceptance of glucocorticoid treatment. Thus, their results should be interpreted with caution. None of the older studies show that lower extremity surgeries improve ambulatory ability or quality of life. Surgical intervention in the early ambulatory stage is not recommended. Surgery may be more beneficial for children in the middle ambulatory stage, although even in this group, the frequency with which surgery is recommended is low compared with past trends.
The goal for lower extremity surgery in the ambulatory stage is to improve ambulation. The consensus in the 2018 Care Considerations is that surgery on the foot and Achilles tendon alone may be sufficient to improve gait in select patients who have significant ankle contracture but good strength in the quadriceps and hip extensors. Surgery on the hips and knees is not recommended. To control an equinovarus foot deformity, the surgeon should consider a tenotomy of the flexor halluces longus, flexor digitorum longus, and posterior tibial tendon if varus is present, in addition to Achilles tendon lengthening. Posterior tibial tendon transfer also can be considered when a varus foot position is observed. These surgeries should only be considered in patients with severe contractures and strong ambulation. Patients should begin walking in short leg casts on the first or second postoperative day and may require ankle-foot orthoses long-term for ambulation after the casts are removed at 4 weeks.
Although the onset of scoliosis in the ambulatory patient is unusual, it is still important to conduct a clinical assessment at least annually. During the ambulatory stage, visual assessment, including use of the Adams’ forward bend test, is appropriate. If a curve is observed, radiographic assessment should follow. Radiography also is valuable if visual inspection alone is inadequate, such as in a child with obesity.
The expert panel also emphasizes routine monitoring of the spine for vertebral fractures, starting at diagnosis or no later than the time of glucocorticoid initiation and then at regular intervals thereafter, as discussed in detail elsewhere.7 Vertebral fractures can be associated with significant postural kyphosis. A postural kyphosis puts a compressive force on the upper lumbar vertebrae, which is usually the apex of the kyphosis. A history of back pain at any stage should also prompt spine radiographs. The goals of treating vertebral fractures with a bisphosphonate as discussed in the “Bone Health and Osteoporosis Management of the Patient With Duchenne Muscular Dystrophy” article found in this supplement7 are to provide pain relief and to prevent worsening of existing and new vertebral fractures. Spinal orthoses are not recommended. The patient should be referred to a bone health specialist to determine the appropriateness of pharmacological treatment with bisphosphonates. More details on proactive monitoring and treating vertebral fractures can be found in the 2018 Care Guidelines, Part 2 and in the “Bone Health and Osteoporosis Management of the Patient With Duchenne Muscular Dystrophy” article found in this supplement.3,7
Families should receive instruction on removing obstacles in the home setting, such as throw rugs and toys, to prevent falls. Special care should be used outdoors when navigating uneven surfaces. Patients using a wheelchair in the community should be reminded to use seat belts at all times because falls out of the wheelchair are a common cause of lower limb fractures.
Osteoporosis and subsequent fractures have been associated with the use of glucocorticoids in many conditions, including DMD. Although vertebral fractures have been a consistent finding in studies in which researchers look at the long-term impact of glucocorticoids on patients with DMD, the effect on limb fractures is not as clear.9–11 In 1 large study, however, researchers examined the rate of long bone fracture in a sample of 143 patients and found that the fracture rate in those treated with glucocorticoids was 2.6 times greater than in the patients who had not received steroids.4 During the ambulatory stage, a lower limb fracture requires aggressive management to maintain ambulation. Early mobilization can be enhanced if internal or external fixation is used instead of casting or splinting.12 Consultation with cardiology and pulmonary specialists is required before placing the child under anesthesia. Postoperative referral to a physical therapist facilitates a focused approach to resuming ambulation quickly and safely.
Fat embolism syndrome has been described in patients with acute lower extremity fracture or trauma. Presenting symptoms include altered mental status, respiratory distress, and tachycardia.13 Immediate medical attention is required because of the high risk of morbidity and mortality. The neuromuscular team should ensure that the medical and orthopedic team treating the child is aware of this condition. Educating family members about fat embolism syndrome and the need to seek emergency medical attention if symptoms are observed is also important.
Early Nonambulatory Stage
Contracture Management: Stretching, Standing, and Orthoses
The focus on contracture management changes in the patient who is no longer ambulatory, with a greater emphasis on the hips and knees at later stages because severe contractures of the hips and knees can make wheelchair positioning challenging and may prevent supported standing. An occupational therapist should develop a home program to focus on upper extremity stretching because the elbow, pronator, wrist, and finger flexors can develop contractures over time.14 Improvements in wrist extension, grip strength, and hand function have been demonstrated in those wearing resting night hand splints. For a further discussion of contracture management, refer to the “Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy” article as part of this supplement.8
Contracture Management: Surgical Interventions
During the nonambulatory stage, surgical intervention of the foot and ankle is generally performed only if the patient requests it. This procedure may help him position his feet on the wheelchair or make shoes easier to wear. Use of daytime ankle-foot orthoses is needed after surgery on the foot and ankle to prevent the contractures from recurring. Surgical interventions for hip and knee contractures are not generally recommended, except in rare cases to alleviate symptoms, because significant correction of these established contractures is unlikely to be achieved.
The widespread use of glucocorticoids has dramatically decreased the development of scoliosis and need for subsequent surgical intervention.5 There is still much to be learned about the impact of glucocorticoids on the spine, including the duration of glucocorticoid treatment needed to reduce the risk of a progressive curve and whether this treatment merely delays the onset.5 In recent studies in which researchers followed young men into their twenties, it was shown that glucocorticoids protect against the development of scoliosis well past skeletal maturity.5
Every clinical examination should include a spine inspection, regardless of glucocorticoid use. In nonambulatory patients, orthopedic surgeons and other experienced clinicians should be able to use visual inspection, although body habitus frequently makes this challenging. Clinicians with less experience may wish to obtain a spine radiograph when a patient with DMD first becomes nonambulatory. Once radiographs show a curve, the skeletal maturity of the patients will dictate further surveillance. Patients with immature skeletons should have a radiograph every 6 months, whereas at least once a year is sufficient for skeletally mature patients. Puberty is delayed in many glucocorticoid-treated patients, so closer surveillance must continue until skeletal maturity is achieved. Orthopedic surgeons should be involved if the patient has a spinal curve of 20° or more. Spinal orthosis is not recommended.15 To maintain an erect position to improve function, young men should use seating systems with lateral supports in their wheelchairs. For more details, see the “Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy” article that is part of this supplement.8
In a 2013 updated Cochrane collaborative report, authors concluded that in the absence of any randomized controlled trials to evaluate the effectiveness of scoliosis surgery in young men with DMD, no evidence-based recommendation could be made.16 Despite the lack of randomized controlled trials, authors of the 2018 Care Considerations noted that in nonrandomized controlled studies, a positive impact of posterior spine fusion on function, sitting balance and tolerance, pain, and quality of life has been shown.16–18 Posterior spinal instrumentation and fusion are recommended in those whose spinal curve is >20°, are prepubertal, and are not on glucocorticoids because progression of the curve is expected. Although patients taking glucocorticoids may still develop a scoliosis, it is reasonable to wait until progression is documented. Patients who do not develop scoliosis may develop kyphosis of the spine due to vertebral fractures that may become severe and symptomatic. Although the fractures may cause pain, there is no risk of neurologic impairment.
When surgery is done to correct scoliosis, it is recommended that those with a pelvic obliquity of >15° also have stabilization and fusion into the pelvis. This helps patients with seating and positioning. Fusion to the L-5 is sufficient for patients who do not have a severe pelvic obliquity. No evidence indicates an advantage of screws over wires or hooks to achieve segmental instrumentation of the spine, but screws provide superior fixation in the lower lumbar spine and should be considered if instrumentation will stop in the lumbar spine distally. With surgical intervention of the spine, the aim is to reduce the patient’s pain, improve his ability to sit comfortably, and prevent further progression.17
Anticipatory guidance during routine neuromuscular clinic visits should continue as an important part of a fracture prevention program even for the nonambulatory child. Seat belt use at all times when in the wheelchair should be emphasized. Fractures also occur in the setting of transfers. Specialized training by physical therapists is recommended when a child becomes fully wheelchair dependent to ensure that all caregivers understand how to transfer a child to and from various surfaces safely. Specialized equipment, such as a Hoyer lift or overhead lift, should be prescribed to assist with transfers and minimize the risk of a child being dropped accidently.
Although the goal of managing a lower limb fracture in an ambulatory patient is to bear weight as soon as possible, a more conservative approach is appropriate for nonambulatory patients. An unstable fracture may require internal fixation, but for bone healing and pain control, splinting alone may be enough. All children need appropriate pain management, but special monitoring may be necessary for children who have pulmonary and cardiac compromise. Fat embolism syndrome should be suspected if altered mental status and respiratory distress occurs after a lower limb fracture or severe trauma.
Late Nonambulatory Stage
Contracture Management: Stretching and Orthoses
Despite long-term stretching and orthotic use, adolescents and adults with DMD frequently have fixed contractures at the hips and knees as well as equinovarus contractures at the ankles. These rarely progress to the point that they interfere with sitting, although they can make positioning in a wheelchair more challenging and make lying flat difficult, which may interfere with sleep. Contractures also occur in the upper extremities. Although no studies have been published on contractures in children treated with glucocorticoids, it appears that the severity of contractures has substantially decreased in these children. For a further discussion of stretching and the use of orthoses to manage contractures in the late nonambulatory stage, refer to the “Rehabilitation Management of the Patient With Duchenne Muscular Dystrophy” article as part of this supplement.8
Contracture Management: Surgical Interventions
Unless factors such as pain, positioning, or skin integrity are concerns, surgical interventions involving the upper or lower extremities are not recommended during this late stage of DMD.
Examination of the spine at every visit is now recommended through the entire life span given the lack of information regarding late progression of scoliosis in the setting of long-term glucocorticoid use and longer life expectancy. When progression is a concern in patients with known scoliosis, yearly anteroposterior sitting spinal radiographs are warranted. For those with a progressive curve, posterior spinal fusion is recommended during the late nonambulatory stage. Consultation with the patient’s pulmonologist and cardiologist is critically important to ensure that the patient’s lung and heart function are robust enough to withstand this surgical intervention. Correction and stabilization of scoliosis is essential to maintain comfort and function. Although it was once thought that the rate of respiratory decline would slow with a spinal fusion, authors have contradicted this understanding in recent studies. In some studies, a slowing progression of respiratory decline has been shown; in others, no difference has been shown.17,19–21 Referral to a seating specialist is recommended because a supportive seating system will provide greater upright support in the wheelchair.
Prevention of fractures should continue throughout the life span, with ongoing education during every neuromuscular clinic visit. As in earlier stages of DMD, fracture reduction, stabilization, and pain control are the treatment goals for an acute fracture in the adolescent and adult during the late nonambulatory stage. Operative stabilization is necessary for proximal femur fractures, whereas a cast or splint may be sufficient for distal femoral metaphyseal fractures, but surgical stabilization may allow the patients to resume sitting and return to school more quickly. When surgical intervention is recommended, special attention by cardiology and pulmonology is required. Wheelchair modifications or rental wheelchairs may be required when a cast is placed.
Special Considerations for Patients Undergoing Surgery
A cardiologist should be consulted before all surgical procedures. The patient with DMD is at particular risk of cardiac compromise during major procedures, such as scoliosis surgery, secondary to blood loss and fluid shifts. An echocardiogram and electrocardiogram should be performed close to the time of surgery. For minor procedures in patients with normal cardiac function, a cardiac evaluation is suggested if the most recent investigation was more than 1 year previously. Anesthesiologists should be aware that cardiac decompensation during surgery is a risk for patients with DMD.
The guidelines on pre- and perioperative respiratory management from the 2010 Care Considerations document remain valid. Respiratory interventions are intended to provide adequate respiratory support during induction of, maintenance of, and recovery from procedural sedation or general anesthesia. In particular, they are designed to reduce the risk of postprocedure endotracheal extubation failure, postoperative atelectasis, and pneumonia. These goals can be achieved by giving patients with significant respiratory muscle weakness noninvasively assisted ventilation and assisted cough after surgery. This can be determined by preoperative pulmonary function test results.
Preoperative training in and postoperative use of manual and assisted cough techniques are necessary for older teen-aged and adult patients whose baseline peak cough flow is <270 L per minute or whose baseline maximum expiratory pressure is <60 cm water. Preoperative training in and postoperative use of noninvasive ventilation are strongly recommended for patients with a baseline forced vital capacity (FVC) of <50% predicted and necessary with a FVC of <30% predicted.
Extubation to supplemental oxygen alone, without concomitant use of noninvasive ventilation, should be avoided unless the patient’s baseline FVC exceeds the thresholds indicated above and blood CO2 levels are monitored to detect hypoventilation caused by muscle weakness or sedation. Incentive spirometry is not indicated owing to the potential lack of efficacy in patients with respiratory muscle weakness and the availability of preferred alternatives, such as mechanical insufflation–exsufflation. Most patients will be able to be extubated within the first 24 hours but should remain under close observation after extubation to ensure adequate respiratory function.
After careful consideration of the risks and benefits, patients with significant respiratory muscle weakness may be eligible for surgery, albeit with increased risk, if these patients are highly skilled preoperatively in the use of noninvasive ventilation and assisted cough.
When young men with DMD are exposed to inhalational anesthetics or when they are administered succinylcholine, the risk of developing anesthesia-associated rhabdomyolysis is increased. This complication is associated with hyperkalemia but is frequently confused with malignant hyperthermia,22 which is a separate entity.
Because of this increased risk, total intravenous anesthesia is strongly recommended. Depolarizing muscle relaxants, such as succinylcholine, are absolutely contraindicated owing to the risk of fatal reactions.
Another major concern when providing anesthesia for spinal fusion surgery is significant blood loss. The use of hypotensive anesthetics to minimize blood loss is not recommended because such techniques provide hemodynamic risk in the setting of cardiomyopathy often associated with the patient with DMD. Cell-saver technology, along with the use of aminocaproic acid or tranexamic acid, can be considered to help manage intraoperative blood loss. Postoperative anticoagulation with heparin or aspirin is not appropriate. Use of compression stockings or sequential compression for prevention of deep-vein thrombosis may be indicated.
The emerging use of experimental treatments and the anticipation of more FDA–approved medications, such as eteplirsen, are expected to change the course of DMD for the ambulatory child. It is unknown how these treatments will affect the musculoskeletal system. However, if started early, they may help prolong walking and subsequent development of contractures and bone health, given greater opportunities for weight bearing and the potential ability to avoid glucocorticoids. Cautious recommendations for surgical interventions are required in light of the relatively unknown trajectory of the child’s course. In future work, researchers should focus on musculoskeletal issues, including contractures, fractures, and scoliosis in the child who receives disease-modifying medications. With improvements in life expectancy, a focus on the natural history of musculoskeletal issues in the adult with DMD is needed, with an emphasis on scoliosis and bone strength.
- Accepted July 26, 2018.
- Address correspondence to Susan D. Apkon, MD, Department of Rehabilitation Medicine, Seattle Children’s Hospital, 4800 Sand Point Way NE, Seattle, WA 98105. E-mail:
The guidelines or recommendations in this article are not American Academy of Pediatrics policy and publication herein does not imply endorsement.
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
FUNDING: Partially supported by the Cooperative Agreement, NU38OT000167, funded by the Centers for Disease Control and Prevention.
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
- King WM,
- Ruttencutter R,
- Nagaraja HN, et al
- Lebel DE,
- Corston JA,
- McAdam LC,
- Biggar WD,
- Alman BA
- Weber D,
- Hadjiyannakis S,
- McMillan H,
- Nortiz G,
- Ward L
- Ward L,
- Hadjiyannakis S,
- McMillan H,
- Noritz G,
- Weber D
- Case L,
- Apkon S,
- Eagle M, et al
- Suk KS,
- Lee BH,
- Lee HM, et al
- Copyright © 2018 by the American Academy of Pediatrics