The hands are the most exposed and stressed parts of the body during the day. Manual professions as well as certain activities such as sports or DIY can be the cause of more or less traumatic injuries to the fingers: sprains, dislocations, fractures, ruptures or stretched tendons . In some cases, the fitting of a finger splint is essential to protect, reduce painful sensations and promote the return of good mobility. There are different types of finger splints, each corresponding to a specific use and purpose. Pharma GDD takes stock of the different situations that may require the use of a finger orthosis and specifies the criteria to be taken into account to choose it well.
Anatomy of the hand: some details
The hand is a part of the body with an extremely complex anatomical structure made up of bones, numerous joints, muscles, tendons, arteries and nerves. All these elements combine to allow the realization of daily movements. However, they can be affected by various traumas that will weaken them and require the wearing of a finger splint, a device responsible for protecting or resting the affected finger(s).
Carpus, metacarpus, phalanges
The bones of the hand are grouped into three distinct groups: the carpus, the metacarpus and the phalanges. The carpus, which allows the junction with the forearm, is made up of eight bones arranged in two rows (proximal and distal) of four bones each. At the level of the carpus, there is an osteo-fibrous canal known as the carpal tunnel . The flexor tendons of the fingers and the median nerve slide in and can be affected by what is called carpal tunnel syndrome.
The metacarpus refers to the set formed by the long bones of the hand , five in number. Like the fingers, the metacarpals are numbered from 1 for the thumb to 5 for the little finger. Their base is attached to the carpus and their upper part is extended by the phalanges.
Each finger has three phalanges , except the thumb which has two. A distinction must be made between the proximal phalanx (first phalanx or P1), the middle phalanx (P2) and the distal phalanx (P3). The metacarpophalangeal joints of the fingers unite the heads of the metacarpals and the bases of the proximal phalanges. Their movements are provided by the lateral ligaments and the palmar plate, a fibro-cartilage firmly attached to the first phalanx. At the level of the phalanges, there are two joints: proximal (IPP), between P1 and P2, and distal (IPD), between P2 and P3.
Muscles and tendons
The bones of the hand are complemented by a set of muscles and tendons of great complexity. By their contraction and relaxation, these elements make possible the different movements of the hand and fingers. Several systems coexist:
- flexor muscles and tendons;
- extensor muscles and tendons;
- the external and internal thenar muscles;
- the dorsal and palmar interosseous muscles;
- the lumbrical muscles;
- the hypothenar muscles.
Arteries and nerves
The hand is supplied by two different arteries : the radial artery and the ulnar artery. From the wrist, the radial artery joins the dorsal aspect of the carpus by passing under the tendons and crossing the muscles. The ulnar artery passes through Guyon’s canal to enter the palm of the hand and join the radial artery through a superficial branch. The venous drainage at the level of the fingers is then done thanks to the complementarity of the deep system and the superficial system.
Several nerves are located in the hand and provide it with both motor skills and sensitivity. The median nerve is, at the level of the wrist, located between two tendons. It joins the hand by engaging in the carpal tunnel and comes out composed of 94% sensory fibers and 6% motor fibers. The ulnar nerve passes through Guyon’s canal with the ulnar artery. Finally, the radial nerve divides into two branches at the level of the elbow and it is the superficial branch which joins the hand following the radius.
Most common injuries and pathologies
The fingers can be affected by many more or less disabling traumas, which explains the diversity of the splints offered. The finger sprain is undoubtedly one of the most frequent lesions with the fracture. It corresponds to the lengthening of a ligament or even to its rupture in the most serious forms and generally occurs following a hyper-extension of the finger , especially in ball sports such as basketball or handball. The sprain causes significant swelling or even a hematoma and, most often, wearing a splint is recommended to immobilize the affected finger.. Thumb sprain is a serious form which is characterized by the tearing of the ligament which is then extracted from the area where it is usually inserted. In this case, spontaneous healing is very difficult or even impossible and surgery is essential to avoid any complications.
Finger dislocation refers to the loss of contact between two articular surfaces. It can be the joint between a metacarpus and a phalanx or between two phalanges. This trauma can be potentially serious and cause significant stiffening of the finger. In the case of a proximal interphalangeal dislocation (between the first and second phalanx), partial immobilization of the finger using a finger splint is advised after the repositioning of the finger. joint.
Finger fractures are common in sports accidents or falls. Only stable forms that are not or only slightly displaced can be treated by wearing a finger orthosis . Fractures of the third phalanx, often referred to as mallet finger or mallet finger, will be treated in the same way with a specific splint that will hold the finger in hyper-extension.
Very common in the population (especially during pregnancy and in women in their fifties), carpal tunnel syndrome is due to compression of the median nerve at the wrist. This nerve is involved in the sensitivity of the thumb, index and middle fingers. When the channel it goes into narrows, it slows down the electrical impulse and leads to feelings of numbness, pain in the thumb, index and middle fingers. A finger splint worn at night helps relieve symptoms. Its prescription will depend on the degree of compression of the nerve.
Another frequent pathology in women from the age of 50: osteoarthritis of the thumb , also called rhizarthrosis. Located at the base of the thumb, at the joint between the trapezium (one of the carpal bones) and the metacarpus, it causes pain that can be particularly intense when performing simple everyday gestures involving the pollici- finger (thumb + other finger). A custom-made thermoformed splint can be prescribed for people with osteoarthritis of the thumb to keep it in the right position.
The different types of finger splints and their indications
Companies specializing in orthopedic equipment have developed different types of finger splints which, depending on each person’s situation, can correct a deficiency or put a traumatized finger to rest in order to guarantee recovery.
Stabilization and immobilization splints
Finger splints intended for stabilization and immobilization prevent movement of the thumb joint or all the phalanges of the other fingers. They can start from the wrist and stabilize a single or several fingers or, more simply, be placed on a single finger. This type of splint is generally recommended in the event of a sprain, a fracture with little or no displacement, following a dislocation of the first and second phalanges or injuries to the third phalanx.
Several stabilizing splints exist: mallet, frog , baseball, stack, single or double guide. Some so-called syndactyly finger splints make it possible to immobilize the affected finger by holding it to the neighboring finger, thus limiting movement.
Extension splints are dynamic splints that help restore range of motion after stiffening or tearing of the flexor tendons. They exert a slight traction on the affected finger to gradually restore its extension capabilities and complete mobility.
This type of finger splint is also indicated to treat what is called buttonhole deformity. This condition is characterized by two elements: hyper-flexion of the joint between the first and second phalanges (curvature towards the palm of the hand) and hyper-extension of the distal joint (curvature upwards) . It can be linked to rheumatoid arthritis, osteoarthritis or an injury such as an extensor tendon dislocation or a finger fracture. The extension splint then makes it possible to maintain the central joint in extension.
Like extension splints, flexion splints are dynamic splints indicated to rework the flexion of one or more fingers. They keep the affected finger in a flexed position and are mainly recommended for rehabilitation following ligament damage or surgery involving a risk of stiffening of the finger.
Murphy rings are discrete finger splints which are intended to correct an incipient malformation of one or more fingers due in particular to rheumatoid arthritis (swan neck deformity). They guarantee complete mobility and autonomy in everyday gestures while preventing the joints from performing harmful movements that would have the effect of aggravating the malformation.
The thumb splint in case of rhizarthrosis
The main treatment for rhizarthrosis is to wear a splint to straighten the thumb and prevent it from sinking into the palm of the hand. The thumb splint also reduces painful sensations due to inflammation of the area, relaxes the muscles and keeps the thumb in a resting position to slow down the phenomenon of joint stiffness. The thumb splint attaches to the wrist and is mainly worn at night or in case of pain occurring during the day.
How to choose your finger splint?
Before choosing a finger splint, it must first be determined for which trauma or pathology it should be used. For this, the ideal is to consult a doctor who will then refer you to an orthopedic specialist if necessary. The finger orthosis can be obtained with a prescription or freely in pharmacies . Depending on the type of splint, it will be necessary to take measures so that it is perfectly adapted to the size and morphology of the finger and to favor splints with pins or straps for optimal support.
Other criteria are to be taken into account when choosing a finger splint. It must be comfortable, light and flexible to cause the least possible constraints in daily life. Finger orthoses are made of different materials: the structures can be aluminum, plastic or entirely in fabric and reinforced with foam or padded fabric for more comfort. This criterion is not negligible, especially when the splint must be worn for several weeks.
Depending on the objective sought and the severity of the trauma, the splint may be worn for a period ranging from a few days for a simple sprained finger to six weeks for an undisplaced fracture.
To be retained
In the event of a sprain, dislocation or fracture of a finger, your doctor will probably prescribe a splint to immobilize and stabilize the affected finger while it heals. A splint may also be indicated in the event of a pathology requiring rest of the fingers, such as osteoarthritis of the thumb, for example. There are different types of finger splints, each with a particular function: stabilization, flexion, extension. The choice of splint will depend on several criteria, in particular the type of lesion. It will also be necessary to take into account the comfort, the lightness and the adjustment of the orthosis to the finger concerned so that it is perfectly adapted and does not cause daily constraints.
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