Congenital Joint and Muscle Disorders
At the Paley European Institute, we provide comprehensive diagnosis and treatment of rare, congenital disorders of the musculoskeletal system—arthrogryposis, Larsen syndrome, popliteal wing syndrome, and disorders associated with RYR1 gene mutations.
What are congenital joint and muscle disorders?
Reasons
The causes of these conditions vary. In many cases, they involve genes responsible for the development of muscles, the nervous system, or skeletal structures (e.g., RYR1, TPM2, ECEL1, FLNB). Mutations may be inherited or arise de novo. Other causes include reduced fetal movement during pregnancy, neurological abnormalities (of the central or peripheral nervous system), abnormalities in muscle structure or function, as well as environmental factors—such as infections, alcohol, or other substances consumed by the mother during pregnancy. In approximately 30% of cases of arthrogryposis, a specific genetic factor can be identified.
Symptoms
The most common symptoms include: polyarticular contractures, joint stiffness, limited limb mobility, abnormal (dislocated) joint alignment, weakness or absence of certain muscle groups, foot deformities (clubfoot), and—in some syndromes—spinal involvement (scoliosis, kyphosis), and facial dysmorphic features. The severity of symptoms varies widely—from mild forms affecting individual joints to severe forms affecting the entire musculoskeletal system.
Diagnostics
The diagnosis is based on clinical evaluation, imaging studies, and—if necessary—genetic testing. Some conditions, such as arthrogryposis, can be suspected as early as a prenatal ultrasound, which allows the medical team to prepare accordingly for delivery. A definitive diagnosis and differential diagnosis (e.g., distinguishing arthrogryposis from Larsen syndrome or a RYR1 mutation) are determined by a team of specialists: a clinical geneticist, a neurologist, and a pediatric orthopedist.
The global standard in the treatment of congenital joint and muscle disorders
Early intervention —treatment and rehabilitation begun as early as possible (in some conditions, such as Larsen syndrome, as early as the first months of life)—significantly reduces the risk of the deformity worsening.
Individualized treatment plan – each patient requires a separate evaluation and a treatment strategy developed jointly by orthopedists, geneticists, neurologists, anesthesiologists, and physical therapists.
Preoperative conservative treatment —where possible, casting, splinting, and physical therapy are used first, and surgical treatment is implemented when it offers a real functional benefit.
Anesthesia safety —in cases involving the RYR1 mutation, we use specialized, non-triggering anesthetic protocols due to the risk of malignant hyperthermia.
When should you see a specialist?
The child is born with visible contractures or dislocations of the joints (shoulders, elbows, hips, knees, feet).
There is limited mobility in the limbs and abnormal positioning of the wrists, fingers, or feet.
A prenatal examination (ultrasound) revealed reduced fetal mobility or a suspected skeletal or joint abnormality.
There had already been cases of arthrogryposis, Larsen syndrome, or other genetic disorders in the family .
A child or adult has difficulty walking, sitting, or performing daily activities due to joint stiffness or instability.
A procedure under general anesthesia is planned, and a family history of malignant hyperthermia (suspected RYR1 mutation) has been identified.
How do we treat congenital joint and muscle disorders?
Diagnostics and Planning
Clinical evaluation, imaging tests, and genetic counseling make it possible to accurately determine the type of condition and plan further management.
Conservative treatment
Plaster casts, splints, and orthopedic devices are used as a first step, especially for the youngest patients.
Surgical treatment
Soft tissue release, tendon transfers, corrective osteotomies, joint reconstructions (hip, knee, foot), and the use of external fixators (e.g., Taylor Spatial Frame, Ilizarov).
Rehabilitation and Long-Term Care
Regular, long-term physical therapy (including NDT Bobath and the Vojta method), psychological support for the child and family, and systematic monitoring of musculoskeletal development.
Categories of medical conditions we treat
Artrogryposis (AMC)
Congenital, multi-joint muscle contractures and joint stiffness of varied etiology, occurring in approximately 1 in 10,000 births. Subtypes include, among others, the classic form, the distal form, fin-like syndromes, and synostosis syndromes.
Larsen syndrome
A genetic disorder (FLNB gene mutation, autosomal dominant inheritance) characterized by multiple joint dislocations (hips, knees, elbows) and spinal instability. Unlike arthrogryposis, the muscles are present and functional—the problem is instability, not joint stiffness.
Popliteal Pterygium Syndrome
A very rare condition (1 in 300,000 births) characterized by membranous skin folds (pterygium) in the area of the joints—primarily the knees, ankles, and elbows—leading to significant flexion contracture of the knee and gait abnormalities.
RYR1 Mutations
RYR1 gene disorders can cause central core disease, congenital myopathies, and arthrogryposis. A key aspect of care is a more conservative surgical approach and safe anesthesia protocols due to the risk of malignant hyperthermia.
What is arthrogryposis?
Arthrogryposis is a congenital condition characterized by multi-joint muscle contractures, joint stiffness, and osseous-articular deformities. It can affect all limbs (classic form) or only the hands and feet (distal form). The condition does not affect the child’s life expectancy or cognitive abilities.
Conservative treatment
Physical therapy started in the first months of life, casting, and splinting—particularly effective in correcting clubfoot deformities of the wrists, hands, and feet.
Surgical Treatment
Soft tissue release, tendon transfer, osteotomies to correct limb alignment, hip, knee, and foot joint reconstruction, and, if necessary, the use of external fixators.
Long-term rehabilitation
Regular therapy using the NDT Bobath, Vojta, and MAES methods, psychological support for the child and family, and systematic monitoring of development.
What is Larsen's Syndrome?
Larsen syndrome is a genetic disorder characterized from birth by multiple joint dislocations and spinal problems. It most commonly affects the hip, knee, and elbow joints. Clubfoot or flat-valgus foot (vertical talus) with dislocated joints may also occur. Larsen syndrome occurs in approximately 1 in 100,000 people worldwide, and the severity of symptoms varies greatly, even within a single family.
Cause
It is most commonly associated with an autosomal dominant defect in the filamin B (FLNB) gene. The type of defect in the FLNB gene can vary among patients, which is why it is sometimes overlooked in standard genetic testing.
Treatment Approach for
Unlike many other conditions, treatment for Larsen syndrome—including surgical procedures to realign the joints—begins very early, sometimes as early as 3–6 months of age, to allow for the proper, rounded formation of the joint surfaces. All joints in the limbs that can be reduced are first treated conservatively (with casts or splints) and, if necessary, surgically. Instability or compression within the spine must also be treated early, as left untreated it can lead to paralysis. With sufficiently early and comprehensive treatment, most patients with Larsen syndrome walk independently and lead active lives.
What is the Popliteal Wing Syndrome (PPS)?
Popliteal pterygium syndrome is a very rare genetic disorder of unknown etiology, occurring in approximately 1 in 300,000 live births. It is characterized by membranous skin folds (pterygium) in the flexor regions of the joints—most commonly the knees, ankles, and elbows—accompanied by abnormalities affecting the face, the genitourinary system, and the musculoskeletal system (including syndactyly, nail dysplasia, and growth retardation). Patients’ intelligence is normal.
Symptoms and Impact on Functioning
The most common symptoms include gait abnormalities, pain in the quadriceps area, rapid fatigue, and difficulty performing daily activities. A “crouch gait” depends on the degree of contracture and the range of motion. In severe, bilateral cases, patients may require the use of a wheelchair.
Treatment Approach
Treatment is based on extensive soft-tissue release (including subtotal fasciectomy with excision of the fascia lata), nerve decompression (sciatic, peroneal, and posterior tibial nerves), and lengthening or transection (Z-plasty) of the ischio-tibial muscles and the gastrocnemius muscle. In the past, gradual joint distraction using an external fixator was used; however, this method often led to contracture recurrence and prolonged joint immobilization. Currently, the preferred strategy is femoral shortening, which “releases” the contracture by reducing the distance traveled by the contracted structures—following this treatment, patients achieve significantly improved gait and limb function.
RYR1 mutations
What are RYR1 mutations?
The RYR1 (Ryanodine Receptor 1) gene encodes a protein responsible for calcium release in muscle cells. Mutations in this gene can lead to central core disease, congenital myopathies, and arthrogrypotic features—ranging from significant muscle weakness to pronounced stiffness of the muscles and joints.
Individualized Orthopedic Treatment for
RYR1-related disorders are treated similarly to arthrogryposis when contractures and joint stiffness are present. A key difference, however, is the persistent muscle weakness, which requires a more conservative surgical approach and carefully tailored, long-term physical therapy to prevent further weakening of the muscles that stabilize the joint.
Anesthesia Safety – Malignant Hyperthermia
A key component of care for patients with the RYR1 mutation is strict management of anesthesia. These mutations are often associated with a high susceptibility to malignant hyperthermia—a potentially fatal reaction to certain inhalational anesthetics and muscle relaxants. Therefore, the surgical and anesthesiology teams follow dedicated, non-triggering anesthesia protocols for every procedure.
Interdisciplinary Care
Treatment is provided through the collaboration of multiple specialists—orthopedic reconstruction (including correction of scoliosis, hip dysplasia, and foot deformities) is combined with neurological care, orthotic care, and intensive pre- and postoperative rehabilitation.
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Paley European Institute: A global standard in Poland
As an integral part of the Paley Institute’s global network, we provide access to the most advanced osseointegration systems, based on standardized and proven medical protocols.
A global network, one standard (Unified Protocol)
We operate within the strict framework of the Paley Institute, which means that every stage of your treatment—from the initial consultation to the final rehabilitation—follows the same rigorous guidelines as in our centers in the U.S. and the United Arab Emirates.
Direct Expertise from the Pioneers
Our team, led by Dr. Karolina Siwicka, MD, PhD, directly carries on the legacy of Prof. Munjed Al Muderis. Dr. Siwicka is implementing her own surgical techniques in Poland, which have revolutionized modern osseointegration worldwide.
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We use only genuine, clinically proven, and CE-certified OPL implants. Thanks to the constant exchange of expertise within our network, we follow up-to-date protocols based on medical evidence, so you can be confident that your treatment is in line with the latest scientific knowledge and is performed in a predictable and consistent manner.
Your most frequently asked questions
Genetic mutations
No. Arthrogryposis is not a progressive condition—contractures and joint stiffness are present from birth but do not worsen on their own with age. However, without proper treatment and rehabilitation, they can become permanent, which is why it is crucial to begin therapy as early as possible.
In most cases, yes. Arthrogryposis does not affect a child’s life expectancy or cognitive abilities, and with early and comprehensive treatment, most patients lead active, independent lives. The prognosis depends on the type and severity of the condition (the “flexible” form has a better prognosis than the “rigid” form).
These are two distinct conditions, although they are sometimes confused. In arthrogryposis, the joints are stiff and the muscles are weak or underdeveloped. In Larsen syndrome, on the other hand, the joints are dislocated (unstable), while the muscles are present and function normally. This distinction is crucial for selecting the appropriate treatment.
It depends on the condition. In Larsen syndrome, treatment—including surgery—may be necessary as early as 3–6 months of age. In arthrogryposis, rehabilitation started before the age of 1 significantly reduces the risk of the deformity worsening. The general rule is: the earlier the treatment begins, the better the results and the lower the chance that repeat procedures will be necessary.
Some conditions, such as arthrogryposis, may be suspected as early as the prenatal ultrasound examination based on limited fetal mobility. However, a complete and accurate diagnosis—especially distinguishing between different syndromes—requires clinical evaluation and, often, genetic testing after birth.
It depends on the specific syndrome. Larsen syndrome is most commonly associated with an autosomal dominant defect in the FLNB gene, which means it can be inherited. In the case of arthrogryposis, a genetic factor can be identified in only about 30% of cases—the rest result from other causes (neurological, muscular, environmental). RYR1 mutations can also be inherited or arise de novo.
Malignant hyperthermia is a potentially fatal reaction to certain inhalational anesthetics and muscle relaxants, and people with a mutation in the RYR1 gene are particularly at risk. Therefore, before every procedure in such patients, the anesthesia team follows specialized, non-triggering anesthesia protocols.