Some of the most challenging conditions in pediatric orthopedics are those intertwined with systemic or genetic disorders. In this post, we will discuss three such conditions – Spinal Muscular Atrophy (SMA), Muscular Dystrophy (MD) (focusing on Duchenne/Becker muscular dystrophy), and Osteogenesis Imperfecta (OI) – each of which affects the musculoskeletal system in profound ways. While these conditions differ (SMA and MD are neuromuscular disorders causing muscle weakness, and OI is a genetic bone fragility disorder), they share common themes: the need for specialized spine care, thoughtful orthopedic interventions, and comprehensive, long-term support for the child’s mobility and health. Families dealing with SMA, MD, or OI often find themselves on a rollercoaster of medical care – from managing the primary disease (like medications for SMA or steroids for Duchenne MD) to addressing the orthopedic complications (like scoliosis, fractures, or contractures). Our goal is to provide an educational and empathetic overview of what to expect and how our pediatric orthopedic team approaches these conditions. We emphasize careful patient selection for surgeries (because these children may have higher risks) and highlight that with experienced, specialized care, we can achieve successful outcomes that improve quality of life. We’ll also talk about the concept of “it takes a village” – long-term support involving many specialists, and how we coordinate that, often serving families through childhood into adolescence as ongoing partners. Whether you are a parent seeking information or a primary care provider looking for guidance, we hope this comprehensive discussion sheds light on managing these rare diseases.

SMA and Muscular Dystrophy: Weak Muscles, Growing Spines

Spinal Muscular Atrophy (SMA) is a genetic neuromuscular condition where certain motor neurons in the spinal cord degenerate, leading to muscle weakness and atrophy. Depending on the type (Type 1 being the most severe in infants, up to Type 3 which is milder), children may have profound muscle weakness – especially in the trunk and limbs. Thanks to breakthroughs like gene therapy and drugs (e.g. Spinraza, Zolgensma), many children with SMA are doing better than in the past, but they still often have significant motor impairments. From an orthopedic perspective, one of the main issues in SMA is scoliosis and spinal deformity. Indeed, scoliosis affects almost all patients with SMA Types 1 and 2, and about half of those with Type 3. The reason is the muscles that normally stabilize the spine are weak, so the spine tends to collapse into a curve over time. This usually becomes evident as the child grows and tries to sit: a toddler with SMA might develop a C-shaped curved spine when sitting unsupported. Scoliosis in SMA is more than cosmetic; it can impair breathing because it collapses the chest and can make seating in a wheelchair difficult due to imbalance. Often, the curve progresses rapidly, especially in non-ambulatory children (those who cannot walk). Bracing is sometimes used to slow scoliosis progression (e.g., a custom molded TLSO brace worn when sitting), but braces alone typically cannot fully stop or correct the curve in the long term – they mainly buy time until a child is big enough or medically stable enough for possible surgery. Physical therapy and specialized seating systems (wheelchairs with good lateral supports) also help maintain alignment as long as possible.

In Muscular Dystrophy (MD), particularly Duchenne Muscular Dystrophy (DMD), the scenario is somewhat similar regarding the spine. DMD is characterized by progressive muscle weakness starting in early childhood (affecting boys, usually). With improved care (particularly steroid medications and cardiac/respiratory support), boys with DMD are walking longer and living longer than in decades past. Historically, once a boy with DMD lost the ability to walk (typically around age 10-12 if not on steroids), within a couple of years they would develop significant scoliosis – with reports of up to 90% of patients (not on steroids) getting scoliosis within 2 years of full-time wheelchair use. Steroids have reduced this incidence dramatically, often delaying or preventing scoliosis by keeping the core muscles stronger for longer. Still, many teens with DMD do develop some spinal curvature. Like SMA, the neuromuscular scoliosis in DMD can affect comfort and respiratory function. Another orthopedic issue in DMD and SMA is contractures (tight joints due to muscle imbalance) – e.g., ankles often get tight (equinus) in DMD, and hips/knees can contract in SMA due to long sitting. While contractures are not the primary focus here, they do require management with stretching, bracing (night splints), or occasionally tendon release surgeries (like Achilles tendon lengthening in DMD to allow the feet to rest flat). Managing contractures is important for positioning (for instance, to sit properly in a wheelchair or to use standing devices).

Orthopedic Interventions: Timing and Types of Spine Surgery

For children with SMA or DMD who develop severe scoliosis, surgical intervention is considered. This is a big decision because these children often have coexisting medical issues (for SMA: respiratory fragility, for DMD: cardiopulmonary concerns due to the dystrophy affecting heart and breathing muscles). The goals of surgery are to straighten and stabilize the spine, which can:

Improve sitting balance (so the child doesn’t lean far to one side, which helps prevent pressure sores and allows them to use their arms more easily if they’re not contending with falling over).
Free up space for the lungs to function (kids and parents often notice it’s easier to breathe and their respiratory metrics improve after a good scoliosis correction).
Reduce pain that can come from large curves or impinging ribs.
Make caregiving (transfers, hygiene) easier with a stable, straighter trunk.

The typical surgical solution is a spinal fusion with instrumentation (rods, screws/hooks) from the upper spine to the pelvis. In non-ambulatory neuromuscular patients, fusing to the pelvis (sacrum) helps correct any pelvic tilt and gives a solid base for sitting. Studies in DMD have shown that spinal fusion can improve quality and quantity of life for those with significant scoliosis – likely by aiding pulmonary function and sitting comfort. In fact, long-term survivors of DMD who had spinal fusion in their teens often report better health stability than those who didn’t. However, not every child is automatically a candidate. We use something akin to the “30–30 rule” for DMD: if the Cobb angle (curve severity) is >30° and the Forced Vital Capacity (FVC, a measure of lung function) is >30% of predicted, then scoliosis surgery is generally recommended. It’s noted that with modern non-invasive ventilation (like BiPAP support), some centers have safely done spinal fusions with FVC as low as 20%. Each case is evaluated individually, balancing the risks of surgery (anesthesia and potential complications in a medically fragile child) against the risks of not doing it (worsening curve leading to even more impairment). The timing is usually when the curve is clearly progressing past that ~30° mark and the child still has moderate pulmonary reserve and before they get too old (surgery in late teens/early 20s is harder if heart and lung function decline further). For SMA type 2 (non-sitters who live into childhood) and type 3 (walkers, milder), similar concepts apply: if a child with SMA has a big curve that interferes with seating or breathing, we consider spine surgery often between ages 8-12, depending on progression. What about younger children with SMA type 1 (who now, with therapy, are living longer)? In very small kids, a full fusion is problematic because it stunts growth of the thorax. In those cases, we might use growing rods or VEPTR (vertical expandable prosthetic titanium ribs) to control the curve while allowing growth. These devices require periodic lengthening as the child grows. The situation is evolving as more SMA infants survive into later childhood with new treatments.

Hip Surgery:

In SMA, the hips often don’t have normal muscle pull, and dislocations can happen (especially in type 2 SMA, where about 30% may have hip dislocation). If the child isn’t walking, dislocated hips often don’t bother them and may be left alone unless they cause pain or complicate care. However, if a hip dislocation causes a pelvic obliquity contributing to scoliosis or makes sitting asymmetric, surgical reconstruction might be considered. In SMA patients who can walk (like some type 3), maintaining hip alignment is more crucial. In DMD, hips are usually fine until late contractures; hip dislocation isn’t common early on.

Extremity and Contracture Surgeries:

As noted, Achilles tendon releases or tibialis posterior transfers can improve foot position in DMD for bracing. In SMA, knee or hip releases might help with hygiene (straightening a knee that’s stuck bent, etc.). These interventions are supportive but the spine often remains the centerpiece because of its large impact on health. One must acknowledge that surgery in SMA/DMD has higher risks than in typical kids. For example, scoliosis fusion in SMA has higher rates of complications like blood loss, infections, or even rare neurological complications. In DMD, the combination of a weak heart and breathing muscles means careful anesthesia planning (sometimes giving steroids or ensuring cardiology clearance, using non-invasive ventilation support post-op, etc.). That’s why we strongly advocate these surgeries be done in experienced centers (like Certified Duchenne Care Centers, for DMD). In such settings, success rates are high and complications manageable. In fact, surgical teams have refined techniques (minimizing time under anesthesia, using cell saver for blood, invasive monitoring for cardiac status, etc.) that make it as safe as it can be. Families often travel (medical tourism) to get to these specialized centers because they feel more secure where there is a depth of experience.

Long-Term Support and Multidisciplinary Care

Whether we perform surgery or not, children with SMA or DMD need lifelong orthopedic and rehabilitative support:

Regular Monitoring: We do routine spine X-rays (frequency depends on severity: maybe annually if mild, every 6 months if a curve is >20° and they’re growing).

Bracing and Equipment: As mentioned, braces for spine or limbs can help. Also, wheelchair modifications – like custom molded seats to accommodate a scoliosis until fixed, or tilt-in-space features for pressure relief.

Therapy: Physical therapy in neuromuscular disease focuses on maintaining flexibility (range of motion exercises to prevent contractures) and optimizing whatever muscle strength exists. Water therapy is great as it allows movement with less gravity. Even after spinal fusion, PT helps regain sitting balance (albeit the fused spine doesn’t move, but they learn to adjust with hips).

Pulmonary care: While not in the orthopedist’s direct domain, we work hand-in-hand with pulmonologists. For instance, before and after spinal surgery, respiratory therapists help with coughing techniques, breath stacking, etc. Post-fusion, many DMD patients have observed slower decline in pulmonary function because the spine is straight (some studies suggest it stabilizes FVC loss).

Care Coordination: These children often have multiple specialists – neurology, cardiology, pulmonology, rehab, nutrition, orthopedics. Our clinic often helps coordinate the orthopedic side with the rest. In pre-op planning for, say, a Duchenne patient, we may hold a meeting with pulmonology and anesthesia to map out how to manage ventilation, or with cardiology to discuss medications around surgery.

Family Education: We educate families on signs to watch (e.g., in DMD, to prolong walking, use ankle braces at night and standers; in SMA, how to position the child to minimize contractures). We discuss energy conservation – as muscles weaken, using lightweight braces or assisted devices (like a power wheelchair sooner vs. later) can reduce fatigue and actually keep kids active in school and social life longer. Some families are hesitant about wheelchairs or standers initially, but once they see the child’s comfort and participation improve, they’re on board.

Second Opinions: We frequently provide second opinions for families of DMD or SMA regarding if/when to do spine surgery or other interventions. Because these are rare diseases, not every orthopedic surgeon sees enough cases to be comfortable with the nuances. A second opinion at a specialized center (like ours) is highly valuable to ensure the timing is right and all precautions in place. We also get referrals from other countries; families will travel (medical tourism) to have complex procedures like spinal fusion for DMD done by teams known for it. We respect how big of a decision this is and spend a lot of time counseling on expectations and outcomes.

Osteogenesis Imperfecta (OI): Brittle Bones and Spine Care

Switching gears, Osteogenesis Imperfecta (OI) – also known as “brittle bone disease” – is a genetic disorder where collagen (a key protein in bone) is abnormal, leading to fragile bones that fracture easily. Children with OI can have a range of severity: some have only a few fractures in their lifetime, others have hundreds and also short stature, bone deformities, and even respiratory issues from chest deformities. Orthopedic care is at the forefront of OI management, addressing fractures, deformities, and spine issues.

Fragility Fractures: Babies with severe OI might break bones even in the womb or during birth. Through childhood, normal activities can cause fractures – a bump, a fall, even changing a diaper can break a bone in severe cases. The orthopedic approach is to stabilize fractures (often with casting or splinting, but frequently we opt for surgical stabilization with rods once the child is big enough, to prevent repeat breaks). For instance, intramedullary rod fixation of the long bones is common: placing flexible rods inside the femur, tibia, etc., to reinforce them. This not only treats fractures but also prevents future ones by providing support. Modern “growing rods” (telescopic rods) can expand as the child grows, reducing the number of surgeries needed to upgrade rods.

Bone Deformities: Because of repeated fractures or the soft bone, children with OI often develop deformities such as bowed legs/arms. Correcting these deformities improves function and decreases pain. We use osteotomies to cut bones and then straighten them, usually combined with rod insertion to maintain alignment. For example, a child with a very bowed femur who can’t stand well might get a femoral osteotomy and rod; afterward, their leg is straighter and stronger, aiding in standing/walking.

Spine in OI: The spine is not spared. About 50-60% of children with OI develop spinal deformities, most commonly scoliosis in the thoracic spine. They may also have kyphosis or a combination (kyphoscoliosis). The vertebrae in OI can be wedge-shaped from compressions (like mini compression fractures over time). Additionally, the ligaments might be lax, so the spine can curve. In severe OI (Type III), the scoliosis can be early-onset and progressive. Bracing for scoliosis in OI has limited effectiveness – OI bones are soft and the curves can be stiff. Often, bracing can help support sitting but doesn’t necessarily stop progression. Once a curve is beyond ~40-50° and the child is of sufficient age (and ideally has had some benefit from medical therapy like bisphosphonates to strengthen bones), we consider surgical treatment.

Spinal Fusion in OI: Operating on an OI spine is delicate. The bones are soft, so screws may not hold well; surgeons often use special techniques like smaller screws with cement augmentation to secure them. Despite the challenges, results can be good: studies have shown spinal fusion in OI can maintain correction long-term, although complication rates are higher (rods can break if bone doesn’t fuse well, etc.). One must also address basilar invagination (settling of the skull base onto the spine) that can occur in some OI patients – that’s a neurosurgical issue but with orthopedic involvement if occipito-cervical fusion is needed to stabilize the neck.

Medical Management: A big difference in OI compared to SMA/DMD is the presence of effective medical treatments that augment orthopedic care. Bisphosphonates (like pamidronate or zoledronic acid) are medications that strengthen bone by reducing turnover. When given to children with moderate to severe OI, these drugs have been shown to increase bone density, reduce fracture rates, and decrease bone pain. We typically coordinate with endocrinologists or metabolic bone specialists to ensure our OI patients are on a bisphosphonate protocol if indicated. Often, children get infusions every few months and the changes are dramatic: some kids who were fracturing monthly pre-treatment go to maybe one fracture a year or less on treatment. This, of course, aids our surgical outcomes too – better bone means our fusions and rods hold better. We usually like to give a few cycles of bisphosphonate before a major surgery if possible to maximize bone strength.

Long-Term Support in OI:

The orthopedic journey in OI is long-term and evolving:

Fracture management: Over time, families become adept at recognizing fractures and we train them in having splint materials at home, etc., for initial care. They have fast access to our fracture clinic. As kids get older, fracture frequency often lessens after rodding and bisphosphonates.

Mobility aids: Many OI kids, especially moderate types, can walk, though maybe with orthotics or crutches to protect from falls. Some use wheelchairs for longer distances or during recovery periods. We encourage weight-bearing as tolerated because it builds strength but caution on high-impact or risky activities. Swimming and aquatic therapy are great for OI, providing exercise with low fracture risk.

Monitoring: We do yearly spine X-rays during growth or sooner if there are signs of curve progression. We also monitor leg length (sometimes repeated fractures cause limb length differences which might need shoe lifts).

Pain management and physical therapy: Chronic pain can be an issue from multiple fractures or spine issues. Our team includes pain management when needed, though bisphosphonates also help reduce bone pain. PT in OI focuses on gentle strengthening and maximizing balance (to prevent falls).

Psychosocial support: Frequent injuries and activity limitations can be tough emotionally. We work with families to ensure children aren’t overly restricted (we want them to enjoy life, with reasonable safety measures). We also emphasize that most OI kids, especially with modern care, can lead full lives – attend school, have a career, etc. They may need to avoid certain contact sports, but they find other passions. One of our OI patients became a competitive swimmer; another, a musician.

Coordination of Care:

Like the others, OI care is multidisciplinary. Geneticists or OI specialists guide overall management. Orthopedics handles the surgical aspects. Endocrinology or metabolic bone experts manage bisphosphonates. Rehab medicine and PT for function. Dentists and ENT for hearing (OI can cause hearing loss in teen/adult years). It’s a lot, and we often act as a central hub because orthopedic.

For a comprehensive evaluation and to explore your treatment options, don’t hesitate to schedule an appointment or seek a second opinion consultation with Dr. Arun Hariharan at Paley Orthopedic & Spine Institute by calling (561) 602-9155.