GLOSSARY

Aplasia

Aplasia refers to the absence or underdevelopment of an organ, tissue, bone, or cell in the body due to a failure of normal development.

Callus

In medical terms, a callus refers to the thickened and hardened area of skin that develops in response to repeated friction, pressure, or irritation. In the context of bone healing, a callus also describes the hard tissue that forms around a fracture during the healing process.

Carpal Bones

Carpals are a group of eight small, intricately shaped bones in the human wrist that form the carpal tunnel. Among these, the scaphoid and lunate are crucial.

The scaphoid connects the thumb side of the hand to the forearm. It plays a vital role in wrist stability. The lunate (red), adjacent to the scaphoid (green), contributes to the intricate movements of the wrist joint. Scaphoid and lunate are connected by a ligament known as the scapholunate ligament. It is crucial for maintaining the stability and proper alignment of the carpal bones, but needs to be released during Ulnarization (Paley Gen 3).

Note that, at birth, there is no calcification in the carpal bones; therefore, they are not seen on X-rays. The ossification follows a distinct timeline – with significant individual variability – until skeletal maturity is reached.

The Metacarpals (yellow) are five cylindrical bones extending from the carpal bones to the fingers (“phalanges”), providing structural support and flexibility to the palm. Each finger has one corresponding metacarpal bone.

Image License: Public Domain (retouched / digitally altered)

CRP value

CRP, or C-reactive protein, is a marker of inflammation in the body. The CRP value is a measurement of the concentration of C-reactive protein in the blood and is often used to assess and monitor inflammatory conditions.

Distraction (soft tissue distraction)

Soft tissue distraction is a medical procedure used to gradually lengthen or separate soft tissues, such as muscles and tendons. This method is employed to treat conditions like contractures or deformities.

For more, see our page dedicated to soft tissue distraction.

Dysplasia

Dysplasia is an abnormal development or growth of cells, tissues, bones or organs.

External Fixator

A medical device frequently employed by orthopedic surgeons to address severe fractures, the external fixator is a circular apparatus featuring pins inserted into the skin and bone to stabilize a fractured bone. Its applications vary; during the Radialization procedure, it separates soft tissues gently.

Notably, in Ulnarization procedures conducted by Dr. Standard it stands as an alternative to the internal fixation method utilized by Dr. Paley. However, it’s essential to acknowledge a heightened risk of infections associated with external fixators due to the direct contact of pins with the skin surface, making them susceptible to contamination. In case of an infection, administering antibiotics is often sufficient for effective treatment.

Image: External fixator after Ulnarization (Dr. Standard’s approach) – Image is courtesy of luckyhand.cz / © luckyhand.cz

External fixator after Ulnarization (Dr. Standard's approach) - Pic is courtesy of luckyhand.cz

FCR – flexor carpi radialis

The flexor carpi radialis (FCR) is a muscle in the forearm that plays a role in flexing and abducting the wrist.

Image License: Public Domain

FCU – flexor carpi ulnaris

The flexor carpi ulnaris (FCU) is a muscle located on the inner side of the forearm. It is responsible for flexing the wrist and adducting the hand.

Image License: Public Domain

Genu varum (in contrast to genu valgum)

Genu varum is a medical term describing a condition where the knees are abnormally bowed outward. This is in contrast to genu valgum, where the knees bend inward.

Image: Anteroposterior (AP) view of the legs in a 2 year old child with rickets.
©Michael L. Richardson, M.D., License: CC BY-SA 1.0

Hip dysplasia

Hip dysplasia is a condition where the hip joint does not develop properly, leading to instability and potential dislocation of the hip socket. It can occur at birth or develop later in life.

Image License: Public Domain

K-Wire

Short for Kirschner wire, a K-wire is a thin, smooth, stainless steel wire used in orthopedic surgery to stabilize bone fragments. It is often used temporarily to maintain alignment during the healing process.

Image: Left hand x-ray after Ulnarization with K-wires inside (Dr. Paley)
© aplasia.org License: CC BY-NC-SA 4.0

Left hand x-ray after Ulnarization with K-wires inside (Dr. Paley)

Metamizol

Metamizol, also known as dipyrone, is a non-opioid analgesic and antipyretic medication. It is commonly used to relieve pain and reduce fever. However, its use has been restricted or prohibited in some countries due to concerns about rare but serious side effects.

Ossification

Ossification is the process of bone formation, including in the wrist. At birth, there is no calcification in the carpal bones; therefore, they are not seen on X-rays. The ossification follows a distinct timeline – with significant individual variability – until skeletal maturity is reached. The two carpal bones that need to allocate the ulna head in between during Ulnarization (Paley Gen 3) – Scaphoid and Lunate – ossify in early childhood, between 2 and 6 years (Lunate: 2-4 years, earlier in girls than in boys; Scaphoid: 4-6 years, also earlier in girls).

Radial Club Hand / Radial Longitudinal Deficiency

A congenital condition characterized by the underdevelopment or absence of the radius bone in the forearm, leading to deformities and functional limitations in the affected hand and arm.

Radialization

Radialization is a surgical procedure involving the repositioning or alignment of structures toward the radial (thumb) side of the forearm, particularly in cases of congenital or developmental abnormalities.

Skeletal maturity

Skeletal maturity refers to the degree of development and maturation of the skeletal system. It is often assessed through various methods, such as bone age determination, to evaluate growth and development in children.

Thrombocytes

Thrombocytes, also known as platelets, are small cell fragments in the blood that play a crucial role in blood clotting. They are essential for wound healing and preventing excessive bleeding.

Transient thrombocytopenia

Transient thrombocytopenia at birth refers to a temporary and typically mild decrease in the number of platelets in a newborn’s blood shortly after delivery.
This condition is considered transient because it is usually a self-limiting and short-lived phenomenon. It often occurs in the first few days of life. It is commonly associated with a newborn’s physiological adjustments during the transition from the intrauterine environment to independent life. The exact cause of transient thrombocytopenia at birth is not always clear. Still, it is thought to be related to factors such as fetal-maternal bleeding during delivery, changes in blood volume, or other transient stressors. In most cases, the platelet count stabilizes and returns to normal without intervention.

Ulnocarpal fusion

Ulnocarpal fusion, or ulnar carpal arthrodesis, is a surgical procedure fusing the ulna to the wrist’s carpal bones. This procedure is typically performed to address conditions such as instability or chronic pain in the wrist, often associated with degenerative joint diseases. It can become necessary after unsuccessful attempts to straighten the wrist in cases of radial aplasia.

During ulnocarpal fusion, the damaged cartilage from the joint surfaces of the ulna and the carpal bones is removed. Then the exposed bone surfaces are fixed together using screws, plates, K-wires, or other fixation devices. Over time, the bones fuse into a rigid connection that eliminates movement at the ulnocarpal joint.

wristfusion

Ulnarization:

Ulnarization is a surgical procedure involving the repositioning or alignment of structures toward the ulnar (pinky finger) side of the forearm, often performed to address congenital anomalies.