≤11 ribs is associated with a number of congenital abnormalities and skeletal dysplasias, including:
asphyxiating thoracic dysplasia (Jeune syndrome)
short rib polydactyly syndromes
chromosome 1q21.1 deletion syndrome
Accessory navicular syndrome occurs when a type II accessory navicular (or "os tibiale externum") becomes painful due to movement across the pseudojoint between the ossicle and the navicular bone.
It can be inferred on musculoskeletal ultrasound if a patient's...
Achondrogenesis refers to a group of rare and extreme skeletal dysplasias.
The estimated incidence is 1:40,000 with no recognised gender predilection.
It is classified as an osteochondrodysplasia, meaning deficiency of both bone and cartilage development.
Acrocephalosyndactyly syndromes (ACS) is a rare group of disorders collectively characterised by:
calvarial anomalies, e.g. craniosynostoses
digital anomalies, e.g. syndactyly
While there can be some overlap in features, they can be primarily classified into the following majo...
Acrodysostosis is a rare skeletal dysplasia characterised by growth retardation, nasal hypoplasia, brachydactyly, midfacial deficiency, mental retardation and deafness.
Most cases are sporadic. Few cases with autosomal dominant transmission have been reported. It is believed to occur...
Amniotic band syndrome (ABS) comprises of a wide spectrum of abnormalities, all of which result from entrapment of various fetal body parts in a disrupted amnion. Due to the randomness of entrapment, each affected individual has the potential to form a unique deficit.
Anterior ankle impingement (AAI) syndrome is the result of chronic repetitive trauma with impingement of the anterior tibia against the talus.
Clinical features of anterior ankle impingement syndrome include painful and limited dorsiflexion and anterior joint line swellin...
Apert syndrome (also known as type I acrocephalosyndactyly) is a syndrome that is predominantly characterised by skull and limb malformations.
The estimated incidence is at 1:65-80,000 pregnancies.
Thought to occur from a defect on the fibroblast growth factor receptor...
Asphyxiating thoracic dysplasia, also known as Jeune syndrome, is a type of rare short limb skeletal dysplasia, which is primarily characterised by a constricted long narrow thoracic cavity, cystic renal dysplasia and characteristic skeletal features. It is also sometimes classified as one of th...
Bertolotti syndrome refers to the association between lumbosacral transitional vertebrae (LSTV) and low back pain, and can be an important cause in young patients.
It is considered controversial and has been both supported and disputed since Mario Bertolotti first described it in 1917. Some st...
Biceps chondromalacia is an attritional lesion of the humeral head caused by repeated abrasion by the intra-articular segment of the long head of biceps tendon.
The long head of biceps brachii arises from the supraglenoid tubercle of the glenoid fossa and has intrarticular and extra-...
Caffey disease or infantile cortical hyperostosis is a largely self-limiting disorder which affects infants. It causes bone changes, soft-tissue swelling, and irritability.
A rare variant known as prenatal onset cortical hyperostosis is severe and fatal, though it is probably a separate entity ...
Camptodactyly arthropathy coxa vara pericarditis (CACP) syndrome is a rare condition principally characterised by
congenital or early-onset camptodactyly and childhood-onset non-inflammatory arthropathy
coxa vara deformity or other dysplasia associated with progressive hip disease
Camptomelic dwarfism, also known as camptomalic dysplasia, is a rare form of skeletal dysplasia.
Camptomelic dwarfism is rare with an estimated incidence of ~1:200,000 births.
Diagnosis is usually readily made at birth or with antenatal ultrasound. It is...
Camurati-Engelmann disease (CED), also known as progressive diaphyseal dysplasia (PDD), is a rare autosomal dominant sclerosing bone dysplasia. It begins in childhood and follows a progressive course.
Common symptoms include extremity pain, muscle weakness, cranial nerve ...
The carpal boss is an unmovable hypertrophied bony protuberance at the base of the second or third metacarpals on the dorsal surface, near the capitate and trapezium.
The condition may represent either or a combination of:
degenerative osteophyte formation
os styloideum (an access...
Carpal tunnel syndrome (CTS) results from compression of the median nerve within the carpal tunnel. It is a cause of significant disability and is one of three common median nerve entrapment syndromes, the other two being anterior interosseous nerve syndrome and pronator teres syndrome.
Carpenter syndrome, also called acrocephalopolysyndactyly type II (ACPS type II) is an extremely rare autosomal recessive congenital disorder
It is characterized by number of features which include:
kleeblattschädel (cloverleaf ...
Chronic recurrent multifocal osteomyelitis (CRMO) is an idiopathic inflammatory bone disorder seen primarily in children and adolescents. It is often a diagnosis of exclusion once underlying infection has been ruled out.
There is a female predominance, with 85% of cases reported i...
Clasp-knife deformity is relatively common congenital anomaly found at the lumbosacral junction.
Clasp-knife syndrome, is one of many causes of low back pain. It occurs when a clasp-knife deformity is accompanied by pain on extension secondary to protrusion of the enlar...
Complex regional pain syndrome (CRPS), also known as Sudeck atrophy, is a condition which can affect the extremities in a wide clinical spectrum.
Two types of CRPS have been described 8:
type 1: no underlying single nerve lesion (formerly known as reflex sympathetic dystrophy)
Conus medullaris syndrome is caused by an injury or insult to the conus medullaris and lumbar nerve roots. It is a clinical subset of spinal cord injury syndromes. Injuries at the level of T12 to L2 vertebrae are most likely to result in conus medullaris syndrome.
The conus medullari...
Cowden syndrome, also known as multiple hamartoma syndrome, is characterised by multiple hamartomas throughout the body and increased risk of several cancers.
Type 2 segmental Cowden syndrome is the association of Cowden syndrome with a Cowden naevus, when it is considered a type o...
Crouzon syndrome is rare disorder characterised by premature craniosynostoses.
abnormal calvarial shape: in severe case can give a "cloverleaf skull"
shallow orbits with exopthalmos
mid facial hypoplasia
It carries an autosomal dominant ...
Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy which can occur from a pathological compression of the ulnar nerve at the cubital tunnel.
It is the second most common peripheral neuropathy of the upper extremity 1,3.
Ulnar nerve comp...
Dysplasia epiphysealis hemimelica (DEH), also known as Trevor disease, is an extremely rare, non-hereditary disease that is characterised by osteochondromas arising from the epiphyses.
The incidence is estimated at ~1:1,000,000 3. There is a recognised male predilection (M:F = 3:1...
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognised male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
Elbow synovial fold syndrome refers to a condition where patients experience a cluster of symptoms due to the presence of synovial folds (also known as synovial fringe or plicae).
It tends to be more common in athletic young adults. It is associated with certain sporting activitie...
Failed back syndrome refers to persistent leg and/or lumbar back pain after a surgical procedure. The pathophysiology of this syndrome is complex, as often the operation was technically successful.
Other names for failed back syndrome include failed back surgery syndrome, post-lam...
Fatco syndrome is a syndrome consisting of
tibial campomelia and
It is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance.
Fuhrmann syndrome and Al-Awadi syndrome are said to be similar to FA...
Focal dermal hypoplasia syndrome is also known as Goltz syndrome, and is named confusingly similar to Gorlin-Goltz syndrome.
A rare disorder that follows X-linked dominant inheritance pattern. More commonly seen in males than female. Worldwide only 200-300 cases have been reported....
Glycogen storage disease (GSD) refers to a number of syndromes which are characterised by a defect in synthesis, metabolism or storage of glycogen.
There are many types of GSD:
type I: von Gierke disease
type II: Pompe disease
type III: Cori or Forbes disease
type IV: Andersen di...
Goodman syndrome is a type of acrocephalopolysyndactyly (often considered type IV). It is an extremely rare genetic disorder characterized by marked malformations of the head and face, abnormalities of the hands and feet, and congenital heart disease. The syndrome is inherited as an autosomal re...
Grisel syndrome is a rare cause of torticollis that involves subluxation of atlanto-axial joint from inflammatory ligamentous laxity following an infectious process in the head and neck, usually a retropharyngeal abscess.
It usually occurs in infants or young children.
Hajdu-Cheney syndrome was first described as cranioskeletal dysplasia 1 in 1948. It is a very rare connective tissue disorder with only 50 cases reported in the literature 2.
It is mostly diagnosed in adulthood or adolescence with the presence of a positive family history...
Hemihyperplasia, also known as hemihypertrophy, is asymmetry in size between the right and left of the body, more than can be attributed to normal variation.
Hemihyperplasia is more scientifically correct than hemihypertrophy as the cells are hyperplastic rather than hypertrophied ...
Iliotibial band (friction) syndrome is a common cause of lateral knee pain related to intense physical activity resulting in chronic inflammation.
Commonly affect young patients who are physically active, most often long distance runners or cyclists. The exact prevalence is unknow...
Ischiofemoral impingement refers to the impingement of soft tissues between the ischial tuberosity and lesser trochanter of the femur, primarily the quadratus femoris muscle. Narrowing of the distance between these two osseous landmarks (ischiofemoral space) predisposes for and correlates with i...
Ischiopubic synchondrosis asymmetry is the characteristic enlargement of one of the ischiopubic synchondroses. While it most commonly a normal variant of the developmental process, it is sometimes thought to be syndromic (then called ischiopubic synchondrosis syndrome or van Neck-Odelberg diseas...
Jaffe-Campanacci syndrome is characterised by:
multiple non-ossifying fibromas of the long bones and jaw
café au lait spots
hypogonadism or cryptorchidism
giant cell granuloma of the jaw
Kasabach-Merritt syndrome, also known as haemangioma thrombocytopaenia syndrome, is a rare life-threatening disease found in infants in which a rapidly growing vascular tumour is responsible for thrombocytopaenia, microangiopathic haemolytic anaemia and consumptive coagulopathy.
Klippel-Feil syndrome (KFS) is a complex heterogeneous entity that results in cervical vertebral fusion. Two or more non-segmented cervical vertebrae are usually sufficient for diagnosis.
There is a recognised female predilection 1. KFS has an incidence of 1:40,000-42,000 2.
Klippel-Trénaunay-Weber syndrome (KTWS) is a syndrome combination of capillary malformations, soft-tissue or bone hypertrophy, and varicose veins or venous malformations. It is considered an angio-osteo-hypertrophic syndrome.
KTS classically comprises a triad of:
port wine nevi
bony or soft t...
Kyphomelic dysplasias (also known as "pseudocampomelia") is thought to be a heterogeneous class of "bent bone" skeletal dysplasias. Entities included in a differential for the class are:
congenital bowing of the long bones
cartilage-hair hypoplasia (CHH; metaphyseal dysplasia, McKusick type)
Lambert-Eaton myasthenia syndrome (LEMS) is rare but is still the second most common neuromuscular junction disease after myasthenia gravis. Two-thirds of LEMS present as a paraneoplastic syndrome secondary to malignancy, most commonly lung cancer but is also associated with breast, ovarian and ...
Langer-Giedion syndrome (LGS), also known as trichorhinophanageal syndrome type II, is an extremely rare autosomal dominant genetic disorder.
The effects are seen mainly on the skeletal system and primarily involves
digits of the hands and feet: phalangeal...
Larsen syndrome (LS) is an extremely rare disorder, often classified as a type of osteochondrodysplasia.
The estimated incidence is thought to be at ~ 1 in 100,000 people. There may be an increased female predilection.
It is characterised by many features i...
Laurin-Sandrow syndrome is a rare disorder characterized by tetrameric polysyndactlyly.
polysyndactyly of the hands (both post-axial and pre-axial)
mirror polysyndactyly of the feet
absence of the radius and tibia
Löfgren syndrome is a specific acute clinical presentation of systemic sarcoidosis, consisting of:
hilar adenopathy: see thoracic manifestations of sarcoidosis
arthritis: see musculoskeletal manifestations of sarcoidosis
Maffucci syndrome is a congenital nonhereditary mesodermal dysplasia characterised by multiple enchondromas with soft-tissue venous malformations (haemangiomas).
On imaging, it is usually portrayed by a short limb with metaphyseal distortions due to multiple enchondromas, which may appear grote...
Marfan syndrome is a multisystem connective tissue disease with autosomal dominant inheritance of defect in fibrillin 1 gene. The affected patients are tall with long disproportionate extremities and have pectus excavatum, arachnodactyly, and may also experience upward and lateral optic lens dis...
Mazabraud syndrome is a rare syndrome comprising of:
fibrous dysplasia: usually polyostotic 2
multiple soft tissue myxomas (intramuscular myxomas): typically in large muscle groups
It is most frequently seen in women (~70%) and usually present in middle age (mean age 46; range 1...
McCune-Albright syndrome (MAS) is a genetic disorder characterised by the association of:
endocrinopathy: precocious puberty
polyostotic fibrous dysplasia: more severe than in sporadic cases
cutaneous pigmentation: coast of Maine 'cafe au lait' spots
Presentation is va...
Medial patellar plica syndrome is one of the conditions that can be associated with the presence of synovial plicae of the knee (in this instance a medial plica). It can be a common source of anterior knee pain.
While it can affect those of any age, it typically involves the young...
Menkes disease, also known as trichopoliodystrophy or Kinky hair kinky vessel syndrome, is an X-linked recessive disorder that results in a derangement in copper handling. It results in low copper levels and subsequently, deficiency in copper dependant mitochondrial enzymes.
Milwaukee shoulder refers to a destructive shoulder arthropathy due to deposition of hydroxyapatite crystals, and identification of these crystals in synovial fluid is the cornerstone of diagnosis.
Milwaukee shoulder frequently affects older women, often with a history of trauma t...
Morgagni syndrome consists of the triad of:
hyperostosis frontalis interna
virilism and hirsutism
History and etymology
It was first described in 1765 by the Italian anatomist and pathologist Giovanni Battista Morgagni (1682-1771)
Morquio syndrome is an autosomal recessive mucopolysaccharidosis (MPS), type IV.
Incidence estimated at ~1:40,000.
Many cases present at ~2 years of age and have normal intelligence. Clinical features:
severe dwarfism (<4 foot)
Mucopolysaccharidoses (MPS) constitute a group of hereditary disorders, one of a number of lysosomal storage disorders, having in common an excessive accumulation of mucopolysaccharides secondary to deficiencies in specific enzymes (lysosomal hydrolases) responsible for degradation of mucopolysa...
Nail-patella syndrome, also known as Fong disease or osteo-onychodysostosis, is a rare autosomal dominant condition which results from symmetrical mesodermal and ectodermal abnormalities.
Clinically, the key feature is absent/hypoplastic nails from birth. Individuals may ...
Olecranon bursitis refers to inflammation of the olecranon bursa. The olecranon bursa is a subcutaneous sac that overlies the olecranon process and contains a small amount of fluid to prevent against injury of subcutaneous tissue and skin from the uncovered bony olecranon.
Osteoporosis pseudoglioma syndrome is a rare autosomal recessive disease that is characterised by severe osteoporosis and blindness. This disease is frequently mistaken for osteogenesis imperfecta.
This disease is encountered in approximately 1 in 2 million births.
Otopalatodigital syndrome type I is a rare genetic disorder marked by the association of
and a characteristic face (with hypertelorism, broad nasal root, prominent supraorbital ridges, small flat nose and downslanted palpebral fissures).
It is ...
Paraneoplastic syndromes occur secondary to the indirect effects of a malignancy and occur remotely to the primary malignancy. Symptoms are mediated by cytokines, hormones or immune cross-reactivity. These syndromes can cause a diverse range of symptoms and can affect multiple systems.
Parsonage-Turner syndrome is an acute idiopathic brachial neuritis.
There is male predominance (M:F 2:1 to 11.5:1) 1. Patients from 3 months to 85 years old have been reported, but the majority are between 3rd to 7th decade of life.
The presentation is typi...
POEMS syndrome is an acronym for a rare multisystem disorder comprising of a minimum of three of the following features in the setting of a plasma cell dyscrasia:
M: monoclonal gammopathy
S: skin changes (including hyperpigmentation and sk...
Poland syndrome refers to a congenital unilateral absence of the pectoralis major and minor muscles and is a recognised cause of unilateral hyperlucent hemithorax.
Poland syndrome is usually sporadic, although rare familial cases have been described 1. It is rare, with an estimat...
Poland-Möbius syndrome, is the combination of Möbius syndrome and Poland syndrome, which although very rare, has been well described 1.
Sir Alfred Poland (1822-1872): English surgeon 2
Paul Julius Möbius (1853-1907): German neurologist 3
Popliteal artery entrapment syndrome (PAES) refers to symptomatic compression or occlusion of the popliteal artery due to a developmentally abnormal positioning of the popliteal artery in relation to its surrounding structures such as with the medial head of gastrocnemius (MHG) or less commonly ...
PPP syndrome is the extremely rare association of pancreatitis, panniculitis, and polyarthritis.
Most commonly affects middle-aged male patients with a history of heavy alcohol use 1,2.
In the majority of cases, abdominal symptoms are mild or absent, makin...
Pre-axial polydactyly refers to polydactyly where the additional digit is towards the first digit of the hand (radial side) or foot (medially).
Pre-axial polydactyly is less common than post-axial polydactyly, with an estimated incidence of 1 in 7000.
Progeria is a term used for any syndrome in which a person is prematurely aged, however, it most commonly refers to Hutchinson-Gilford progeria syndrome (HGPS).
Although the primary clinical manifestations of progeria include short stature and skin changes, the disease is...
Pronator teres syndrome (also called pronator syndrome) is one of three common median nerve entrapment syndromes; the other two being anterior interosseous nerve syndrome and the far more common carpal tunnel syndrome. It comprises a constellation of signs and symptoms that result from compressi...
Proteus syndrome is a rare congenital, multisystemic, hamartomatous condition characterised by asymmetrical overgrowth of almost any part of the body and a broad spectrum of manifestations. It can affect tissue from any germinal layer. It is suspected to be a genetic condition, but a particular ...
Quadrangular space syndrome (QSS) is an uncommon diagnosis mainly because of lack of literature on the subject and possible misdiagnosis.
QSS is present on ~1% of shoulder MRIs 6.
Patients present with posterior shoulder pain and paresthesia over the later...
Radial tunnel syndrome is an entity that refers to entrapment of the radial nerve in the forearm, as it occurs in the supinator syndrome. Some authors believe this is an early form of the posterior interosseous nerve syndrome 5.
The syndrome is characterized by pain along...
Reactive arthritis (ReA) is a sterile inflammatory arthritis that follows an infection at a different site, commonly enteric or urogenital. It is classified as a type of seronegative spondyloarthropathy.
Reactive arthritis was formerly known as Reiter syndrome/disease, which is the...
Rett syndrome is a rare neurodegenerative disease seen in young girls in the 2nd to 4th months of life. The majority of cases result from a mutation in the MECP2 gene; a more severe subset of the disease arises from a CDKL5 mutation1.
Following a period of normal develop...
Ruvalcaba syndrome (also known as Ruvalcaba-Myhre-Smith syndrome) is one of a group of disorders related to congenital skeletal disturbance. It is characterized by:
mental (not invariably) and physical retardation
The SAPHO syndrome is an acronym that refers to a rare condition that is manifested by a combined occurrence of 2
It classically tends to present in young to middle-aged adults. Presentation in the paediatric pop...
Sclerosteosis is a rare autosomal recessive bone dysplasia resulting in sclerosis and hyperostosis, particularly of the skull, mandible and tubular bones. It is closely related to Van Buchem disease 1.
Sclerosteosis is a very rare disease, with only around 100 cases reported. Ther...
The seatbelt syndrome is the constellation of traumatic injuries associated with three-point seatbelts:
lumbar spine fracture
Short rib polydactyly syndrome(s) (SRPS) comprise of a rare group of severe osteochondrodysplasias. There are four major recognised types present:
type I: Saldino-Noonan type
type II:: Majewski type
type III: Verma-Naumoff type
type IV: Beemer-Langer type
There may also be other very rare t...
Sinus tarsi syndrome (STS) is the clinical syndrome of pain and tenderness of the lateral side of the hindfoot, between the ankle and the heel. Imaging often demonstrates the ligaments and soft tissues in the sinus tarsi are injured.
Sinus tarsi syndrome has been described in danc...
Snapping hip syndrome is simply an audible snapping sound produced during motion of the hip. It has both intra- and extra-articular causes.
iliotibial band snapping over the greater trochanter (iliotibial band syndrome - not always audible)
Spondylocostal dysostosis (SCDO) is a rare condition characterised by short-trunk dwarfism secondary to developmental anomalies of the vertebrae and ribs. Previously the condition Jarcho-Levin syndrome (also known as spondylothoracic dysostosis) was grouped together with spondylocostal dysostosi...
Spondyloepiphyseal dysplasia is a type of skeletal dysplasia that mainly involves the spine and proximal epiphyseal centres.
short trunk with protruding abdomen
craniovertebral junction stenosis
Stevens Johnson syndrome (SJS) is an acute inflammatory skin condition.
SJS is on a spectrum of disease with toxic epidermal necrolysis (TEN) at the more severe end. Terminology depending on how much surface area is involved 1,2:
SJS-TEN overlap: 10-30%
Stewart-Treves syndrome refers to an angiosarcoma seen in the setting of post-mastectomy lymphoedema. It however only accounts for 10% of all angiosarcomas seen in the setting of chronic post-mastectomy lymphoedema.
Tarsal tunnel syndrome refers to an entrapment neuropathy of the posterior tibial nerve or of its branches within the tarsal tunnel. This condition is analogous to carpal tunnel syndrome.
The most common symptoms are pain and paresthesia in the toes, sole, or heel and the...
Turner syndrome, also referred as 45X, is the most common of sex chromosome abnormalities in females.
The incidence is estimated at 1:2000-5000 of live births, although the in utero rate is much higher (1-2% of conceptions) due to a significant proportion of fetuses with 45X abor...
Ulnar dimelia or mirror hand syndrome is a rare congenital anomaly of the upper limb characterized by absence of the radial ray (including thumb), duplication of the ulna and duplication of the ulnar halves of the carpals, metacarpals and phalanges 1.
The embryology of mi...
Ulnar styloid impaction syndrome refers to wrist pain due to a long ulnar styloid process impacting upon the triquetral bone.
An unlar styloid >6mm in length is commonly regarded as being long. Impaction results in chondromalacia of the opposing articular surfaces, i.e. the proximal ...