The upper limb is a polyarticulate structure whose essential function is the positioning of the hand in space to obtain a gesture most suited to the goal sought. In this respect, the prehension strategy is the most characteristic of this function.Visual control is essential to the realization of this voluntary act with little automation.
The elements of this polyarticulated chain have certain characteristics. The joints have a kinematics and tribological qualities dictated by their three-dimensional shape and the preservation of the cartilage. The study of joint congruence, summarizing at best the structure-function duality of the joint, is therefore an essential element of the analysis of traumatic lesions. This congruence depends mainly on the state of the cartilage which is radiotransparent and, moreover, practically without capacity for regeneration. The intermediate segments have a duality structure – function based on a preservation of less complex form, because it is summarized in conservation of characteristic axis, with, moreover, a certain degree of tolerance. Note that in the upper limbs it can be wider than in the lower limbs where the need for synergy of the limbs and preservation of the balance leads to a more restrictive pattern of functioning.
Finally, these intermediate segments consist of bone, which has a maximum regeneration capacity.
In this polyarticulated chain, the muscles have a multiple function: active mobilization of the joints (remembering that the tendon punctual insertions, which are susceptible of being pulled out, are in the paraarticular metaphyseal zone), articular dynamic stabilization (by agonist – antagonist ), contribution to the resistance of the intermediate segments by their large diaphyseal insertion realizing composite structures.
Knowledge of the characteristics of these various structural elements and the understanding of the traumatic mechanism are essential for proper analysis of the lesional imagery. It must be remembered that the trauma is most often indirect, the lesion not sitting at the point of application of the vulnerable force, and always imagining the exhaustion of traumatic energy beyond the easily visualized structures. A good knowledge of the types of trauma and of the affected structure gives its full significance to the analysis of the lesion, leading to the best possible additional investigations and therapeutic management.
Shoulder and shoulder girdle:
The stump of the shoulder includes the clavicle, the scapula, the sternoclavicular and acromioclavicular joints.
The involvement of the stump is clinically differentiated from the glenohumeral joint by a preserved glenohumeral mobility.
The traumatic lesions of the stump:
Fractures of the clavicle:
They are linked to a direct drop on the shoulder strap (AVP or sports trauma). Achievement of the average third is the most frequent, with the most often displacement.
Fractures of the external third are rare (10%), not displaced, and often go unnoticed or can be confused with acromioclavicular dislocation. Lesions of the internal third are exceptional.
Clinic:
The patient presents with the classic attitude of traumatized upper limb. There is a projection of the internal bone fragment, a lowering of the shoulder.
The pain is exquisite to palpation. There is a painful functional impotence but with preservation of the movements of the glenohumeral joint.
Imaging. The suspicions of lesion of the middle third are explored by a frontal radius and ascending radius; if a lesion of the external third is suspected, an incidence of shoulder face and the profile of Lamy are realized.
For middle-third fractures, there may be an upward displacement of the internal fragment (under the traction of the sternocleidomastoid muscle), a downward displacement of the external fragment (related to the weight of the upper limb), an overlap (in relation to the contraction of the pectoral muscles). These fractures have exceptional surgical indications, mainly as a function of the topography of the line, the number of fragments and their displacement.
Complications:
Immediate complications are rare, mainly by venous lesion of the axillary pedicle by the internal fragment in fractures of the middle third. Late complications arterial compression on hypertrophic callus are classic but very rare. The frequent association with costal fractures must make them seek. Fractures of the external third are more difficult to see and most often not displaced.
Unrecognized, they can evolve towards a resorption of the external third of the clavicle.
Acromio-clavicular sprains and dislocations:
They are linked to a forced lowering of the shoulder, a common trauma to sportsmen and women. There are three degrees of impairment: sprains (displacement), subluxation (visible displacement only during sensitization) and dislocation (permanent displacement) from the outer end of the clavicle to the top and to the rear of the collarbone. made of the rupture of the coraco-clavicular ligament, or even of the delto-trapezoidal screed.
Clinic:
In addition to the exquisite pain of the shoulder, in the case of dislocation there is mobility in piano touch from the outer end of the clavicle. The mobility of the shoulder is not very painful, and the movements of the glenohumeral are preserved.
Radiology:
In dislocations, joint space is widened with displacement of the outer end of the clavicle up and back. In case of doubt, a comparative incidence of face on a single cliché taking both shoulders verifies the symmetry of the interlining.
If a doubt persists, a stereotype sensitized by port of charge can be realized to objectify the subluxation. The digitalized photographs allow a better visibility of this articulation often overexposed by conventional clichés.Snapshots are normal in sprains.
The therapeutic choice (surgical indication) is in fact difficult because the spontaneous evolution has no great functional consequences.
Sterno-clavicular dislocations:
They are rare, often unrecognized and in a context of polytrauma. Their mechanism may be indirect by falling on the shoulder stump. Their rarity is due to the fact that the shock is absorbed by the clavicle. The antero-external projection of the inner end of the clavicle evokes an anterior dislocation. In posterior dislocations (much more rare), depression is more rarely observed. In both cases, the pain is exquisite and a jump is perceptible on palpation.
Imaging. The cliché of the face of the clavicle and the oblique centered on the sterno-clavicular joint, are useless. The diagnosis is clinical and can be confirmed by the CT scan.
We must look for lesions associated parietal homo or contralateral. Posterior dislocations may be accompanied by vascular complications at the subclavian or carotid axis.
Fractures of the scapula:
They are classified according to the topography of the line and the functional repercussion. True articular fractures or fractures of the glenoid have a direct repercussion on the glenohumeral kinetics. Extra-articular fractures or fractures of the scale do not have functional consequences even if it persists a deformation because this zone is free of insertion of the peri-articular muscles.
Juxtaglenoid fractures or fractures of the cervix, coracoid and acromion are likely to cause joint disorganization, due to the presence of musculo-tendinous insertion zones.
Clinical. The shoulder is augmented in volume, the pain is global, except in isolated extirpations of the coracoid, where there is only a localized pain point, increased by the disfigured flexion of the forearm (linked to the insertion of the short portion of the coracoid). biceps) or in the case of a localized fracture in the acromion, the pain is identical to that of the lesions of the acromio-clavicular joint. Functional impotence is a function of the type of fracture.
Imaging:
If the patient is valid, at least one incidence of shoulder face and a profile is achieved by trying to clear the scale (arm abduction, hand over the head).
In the absence of displacement, these fractures can be misunderstood. The fracture line, its topography and the different features of the splitting of the glenoid, pillar, and tortoiseshell should be investigated, trying to determine whether the involvement is articular, juxtaglenoid or extra-articular. In fact, the pre-therapeutic assessment is performed by CT scans.
Case of polytrauma:
In view of the frequent occurrence of these fractures in the context of polytrauma, the initial assessment is often limited to incidences of necessity in supine position (face and profile by inclination of the tube). In polytrauma patients, these fractures may correspond to an impaction of the shoulder stump in the rib cage with costal fractures, pneumothorax,.Their association with thoracic lesions, in particular parenchymatous lesions, is frequent and related to the violence of the shock. The diagnosis of fracture of the scapula is sometimes made only on the chest radiograph, and some are only detected during the chest CT scan.
Lesions of the glenohumeral joint:
Antero-internal dislocations:
These are the most common dislocations of the adult. They are linked to a direct impact, with fall on the arm in abduction-external rotation. The same mechanism in the child or the old man results in a bone lesion rather than a capsulo-ligamentary lesion. The antero-internal topography of the dislocation is the most frequent (more than 95% of the glenohumeral dislocations).
Clinic:
The attitude of the traumatized upper limb is accompanied by the sign of the epaulette, with emptiness of the glenoid and blow of the ax constituted by the insertion of the deltoid and the abduction of the arm. The humeral head is palpated in the delto-pectoral furrow in front. Mobilization is impossible because of pain.
Imaging. On the incidences of face, of Lamy’s profile or on the transthoracic profile, the glenoid is empty, the head projecting below the coracoid and in front of the glenoid (the most frequent subcoracoidal anterior-internal form).
An anterior glenoid fragment and an associated fracture of the trochiter should be examined. On the control plates after reduction (face plus Lamy incidence, with or without an incidence of Garth or apical view, in the immobilization position of the patient), an anterior and inferior fragment of the glenoid and / posterior humeral notch. In the elderly, the pure dislocations are exceptional, it is always necessary to seek an associated fracture of the humeral collar which must be known before the possible maneuvers of reduction. Moreover, in the majority of cases, they are accompanied by a rupture of the cap.
Complications. Antero-internal dislocations can be complicated, in the acute stage, by an involvement of the circumflex nerve, which is transient in general, leading to anesthesia of the stump of the shoulder. The associated brachial plexus lesions are mainly related to the mechanism of elongation during the trauma. Ischemia due to involvement of the axillary artery is rare. The fracture of the antero-internal margin of the glenoid, the notches of Hill Sachs or Malgaigne, the ruptures and disinsertions of the glenoid rim, come within the framework of recurrent dislocations and chronic instability.
Posterior dislocations:
They are much rarer (5%), frequently unrecognized.
The mechanism is an indirect trauma in forced internal rotation, which explains their occurrence during convulsive seizures.
Clinic:
The most common form is subacromial.
The distortion is discrete, and may pass unnoticed; only the absence of external rotation is evocative of the diagnosis.
Imaging:
Given the usual absence of height displacement of the humeral head, the diagnosis is not easy: on the incidence of face, the only sign is the impossibility to clear the glenohumeral interligne, evoking a bad incidence, sometimes associated with a pseudo enlargement of the glenohumeral space and an internal rotation of the humeral head.Conversely, there may be a reduction in the height of the acromio-humeral space or a projection of the humeral head on the basis of the coracoid process. In profile, the head projects behind the glenoid or straddles the posterior border.The association of a surgical or anatomical cervical fracture is rare. The realization of a CT will confirm the diagnosis of dislocation in case of doubt and will make an accurate lesional assessment in case of irreducibility.
The erecta dislocation:
It is an inferior luxation, the arm is in irreducible abduction.
The diagnosis is clinical. The photographs are made in control after reduction. The risk is essentially an elongation of the brachial plexus.
Fractures of the upper end of the humerus,
In the young subject, they follow a violent trauma.
In the elderly, they are often linked to minor trauma. The shock is direct or indirect during a fall on the arm. Fractures of the surgical cervix are frequent, fractures of the anatomical neck rare, detaching the cephalic cap. Tuberosal fractures (united or doublo-bone) are sometimes misunderstood when isolated. Cerebrospinal fractures associate these three lesions.
Clinical. There is an abduction deformation of the arm, resembling that of dislocation, without glenoid vacuum with an increase in the volume of the shoulder. The pain is global. Mobility is impossible because of pain.
Imaging:
On the face and profile images, the visibility of the fracture line at the surgical cervix is sometimes difficult to diagnose.The tilt of the humeral head and the modification of the cephalo-diaphyseal angulation are very evocative. There may be an aspect of lower pseudoluxation of the glenohumeral linked to a muscular strain, and spontaneously regressive.
For isolated tuberosic fractures, the fracture line and displacement are easier to diagnose with respect to the trochiter, more difficult for the trochin.
The existence of elective pain should encourage the production of rotating pictures. The cephalo-tuberosal fractures are well detected in the standard images, but the pre-therapeutic assessment giving the number of fragments, the involvement of the tuberosities and the state of the bicipital gutter is performed by the scanner.
The ruptures of the cuff and tears of the external tuberosity:
They sometimes occur on healthy headdress during direct trauma in young subjects or, more often, on pre-existing tendinopathy. In the elderly, they are often associated with dislocation. On examination, there is no deformity, maintaining abduction of the arm is difficult or impossible. The images eliminate a bone lesion or acromioclavicular joint. A tearing of the trochiter is equivalent to a rupture of the headdress. Calcifications may be evidence of an anteriorly pathological cap. The ultrasound can confirm the rupture, but the pre-surgical assessment will be done by MRI (topography, extent of rupture, muscular balance) or failing by arthro-scan of the shoulder. The evolutive risk is the constitution of a subacromial conflict in relation to the postero-superior displacement of the trochiter.
The trauma of the arm:
The humeral diaphyseal fracture:
It is rarely linked to a direct trauma, the trait is then transversal. Most often, the trauma is indirect at the elbow, causing an oblique line, sometimes spiroid. A deformation of the arm, with angulation at the antero-external apex, shortening of the arm, and internal rotation of the lower segment, is observed.
Mobility is reduced by pain and deformity, which most often necessitates orthogonal necessity incidences, as close as possible to the face and profile implications of the humerus, taking at least an incidence l shoulder and elbow to judge a possible rotation. The fracture line is located at the middle third (always below the insertion of the pectoral major) or at the level of the lower third, with angulation at the antero-external apex. The treatment is surgical closed-hearth.
The risk of humeral vascular disease is limited, but it is necessary to check the presence of the radial pulse. Radial nerve involvement (inability to raise the hand), median nerve (anesthesia of the dorsal aspect of the 1st metacarpal) should be investigated. Pseudarthrosis is a possible late complication.
The trauma of the elbow:
Clinically, deformities such as dislocation of the elbow, dislocation of the humeral palm, fracture of the olecranon, and deformities such as fracture, dislocation of the radial head and fracture of the capitellum whose diagnosis can be misunderstood.
The elbow is distorted:
The dislocation of the elbow:
Secondary to an indirect traumatism in the axis of the forearm, it is seen mainly in the young adult. Dislocation is usually postero-external. The same mechanism results in a fracture of the humeral palette in the elderly.
Clinical. The forearm is shortened, with deformation of the epitrochlear-olecranon-epicondyle triangle, anterior projection of the palette, and posterior of the olecranon.
Imaging:
The elbow is blocked in bending and only incidences of necessity can usually be realized: either one face, incident ray corresponding to the bisector of the bending angle of the elbow, or two face shots with incident ray perpendicular to the arm and then ‘forearm. The profile cliché without mobilization of the patient does not pose problems of realization.
The sigmoid cavity is empty on the profile, the olecranon projects between the two pillars of the palette on the overall face incidence. The search for a fragmentary fracture of the radial head, and / or the condyle, and / or the corone is best obtained on the face plates perpendicular to the two segments. The search for fragments must also be done on the post-reduction control clichés.
Complications. Since the risk of stretching, compression and even rupture of the humeral artery is not negligible, the search for the radial pulse before and after reduction is necessary. Chronic laxity is exceptional, but there is the possibility of secondary formation of osteomas.
Fractures of the humeral palette:
They are seen in the elderly. The mechanism of the trauma is the same as that which causes a dislocation of the elbow in the young adult. It also exists in young subjects during very violent trauma. It is often multi-fragmented. The elbow is increased in volume, and painful, there is a deformation of the epitrochlear-olecranon-epicondyle triangle if the fracture is sus and intercondylar.
Imaging. Since the elbow is not blocked, the face plate in extension and the bending profile can be made.
The transversal superior condylar fracture line may be accompanied by posterior displacement of the distal fragment.The choice of treatment depends on the presence of joint damage that should be investigated; in fact, this leads to a surgical treatment of stabilization allowing an early mobilization and reducing the risk of secondary stiffness. The articular line is vertical, sagittal in fractures in Y (sup and intercondylar).
Unicondylial involvement is rare, and a trochlear line is required. Sometimes only the signs of haemarthrosis with repression of the fatty fringes of the coronoid fossa and the appearance of the fatty triangle of the olecranon fossa are visible. The realization of obliques is then necessary in the search for the articular trait.
Comminuted fractures are common.
The fracture of the olecranon:
It is often due to a direct shock when falling on the elbow in flexion and can then be opened.
Much more rarely, it is linked to an effort of flexion thwarted by the contraction of the triceps.
Imaging. The fracture is articular, with upward displacement of the olecranon fragment under the action of the tricipital contraction. The epitrochlear-olecranon epicondyle triangle is deformed, the pain is local, the elbow active extension impossible. On the incidences of the face and especially on the cliché of profile of the elbow, the fracture line is transversal articular, with ascension of the proximal fragment. The main complication is the possibility of a pseudarthrosis that is often poorly tolerated.
The elbow is not deformed:
Fracture of the radial head:
It is considered an aborted dislocation. Due to an absence of deformation, of relatively retained mobility, it can be clinically unknown.
Pain with prono-supination is an important sign.
Imaging. The face and profile images must be completed either by the specific incidence of the radial head and the capitellum or by oblique. As the fracture line is not always visible, this research is mandatory if there are signs of haemarthrosis (eg, the backfilling of the fatty triangles of the coronoid and olecranon fossae) or an effacement of the fatty edema of the supinator. The fracture line is perpendicular to the glenoid, there may be a sinking or a displacement of the fragment. An associated fracture of the condyle should be sought.
The dislocation of the radial head:
Associated with a fracture of the upper third or the middle third of the ulna, it constitutes the fracture of Monteggia. It is linked to indirect trauma.
Imaging. The images of the face, and especially the profile of the elbow, reveal the loss of articular relations between the humeral condyle and the radial head moved forward. The discovery of this dislocation must cause the realization of forearm images entirely in search of the fracture of the ulna. Reduction of the fracture of the ulna leads in general to the reduction of the dislocation of the radial head.
The irreducibility of the radial head by capsulo- ligament interposition is rare and requires surgical reduction.
The evolutive risk is the permanent dislocation of the radial head.
The fracture of the capitellum:
It is an intra-articular fracture fracture. The fracture line in the coronal plane detaches an anterior condylar fragment.Due to the absence of deformation, it is often misunderstood, and can be discovered a posteriori because of blockage phenomena of the fragment.
It is sometimes associated with a complex fracture.
Imaging. In the absence of displacement of the fragment, the fracture line is rarely seen, it is to be investigated carefully on the profile, especially if there are signs of haemarthrosis without further detectable lesion. When the fracture line is visible, it detaches an anterior condylar fragment, or leaves a condylar notch. The size of the fragment and its extension to the trochlea will condition the surgical gesture (synthesis, ablation or therapeutic abstention) according to the age of the patient.
The trauma of the forearm:
Fractures of the 2 bones of the forearm:
They involve the diaphysis of both bones and are most often due to an indirect shock by falling on the hand. In this case, a radiolucent dislocation is associated with a fracture apparently isolated from the radius, with an isolated fracture of the ulna, a dislocation of the radial head. More rarely, the mechanism is a direct violent shock. The less violent direct shocks result in an isolated fracture of one of the two bones due to the exhaustion of the traumatic force.
Clinic:
The deformation of the forearm is bayonet, more or less marked, associated with a shortening.
The mobility of the elbow and the wrist is preserved, prono-supination is limited and painful.
Imaging. The frontal and forearm images should include the elbow and wrist. The fracture line is located at the middle third or intermediate third-third union of the diaphysis, it is transverse or oblique, exceptionally spiroid.
It is necessary to appreciate the importance of the displacement and especially the rotation. The treatment is surgical.If the mechanism is of the indirect type, the finding of an isolated fracture of one of the bones of the forearm should cause the associated lesions to be investigated: dislocation of the radial head in case of fracture of the ulna or inferior radio-cubital disjunction in case of fracture of the radius. Immediate vascular and nerve complications are rare. At a distance, the evolution towards a pseudarthrosis is possible, rarely towards a synostosis of the two bones of the forearm.
The isolated fracture of the ulna:
It is a consequence of a direct shock (defense reflex).
The distortion is not important, the pain is precise at the palpation of the ulnar crest, there is a discomfort in prono-supination. Face and profile incidences include elbow and wrist. The fracture line is transverse to the level of the upper third of the ulna, associated with an angulation with an external apex. Anterior dislocation of the radial head (Monteggia fracture) should be sought when the trauma is not direct.
The isolated fracture of the radius:
It is due to direct trauma. In cases of indirect trauma, it is usually associated with lower radio-ulnar dislocation. The frontal and profile incidences include the elbow and wrist to find the lower radio-ulnar involvement.
Wrist trauma:
The finding of a wrist deformation leads to radial or radiocarpal lesions, in the absence of deformation towards intracarpian lesions.
The wrist is clinically distorted:
Fracture of the lower end of the radius:
These are the most frequent lesions. In hyperextensive wrist trauma (eg fall in the elderly), the displacement of the distal segment is dorsal, the back of the wrist is deformed on the back of the fork. If the fracture line is supra-articular, it is
of a fracture of Pouteau-Colles. The trait can be articular detaching a postero-internal fragment, or both supra and intra-articular in complex fractures in T (the articular trait being sagittal most often).
In hyperflexional wrist trauma, the displacement of the distal segment is ventral with a spoon belly deformity. If the fracture line is susarticular, it is the fracture of Goyrand.
The line may be marginal anterior and be accompanied by anterior dislocation radiocarpian. In both cases, the radial styloid is at the same height as the cuboidal styloid. Pain is supra-articular, mobility preserved but limited by pain.
imagery
These distorted wrists are explored by face and profile shots. They allow the visualization of the stroke (s), their topography, the displacement and possible tipping of the distal segment in dorsal or ventral. The degree of anterior or posterior metaphyseal compression must be assessed, as well as the articular prolongation of the or traits that modify the surgical gesture. The oblique incisions allow a more precise balance, especially in the comminuted fractures.Tensile photographs can be performed under general anesthesia at the block, in search of free fragments. The presence of a fracture of the ulnar styloid has no therapeutic effect. The immediate complications of these fractures may be irritation of the median nerve, related to displacement. Later complications are mainly the occurrence of a neuro-algodystrophic syndrome.
The perilunary dislocations of the carpus:
They are related to hyperextension trauma of the young subject. Medocarp sprain, fracture of the scaphoid, retrounar dislocation of the carpus, anterior dislocation of the semilunar, correspond to evolutionary stages related to the same mechanism, only the last two stages being expressed by a deformation of the wrist.
Imaging: The incidence
s of the face and of the profile of the wrist may be supplemented by an incidence of the scaphoid.
The loss of the continuity of the proximal and intermediate curves of Gilula with a piriform aspect of the semilunar is observed in the frontal plate. On profile incidence, the alignment of the middle column is changed.
In the retrounar dislocation of the carpus, the large bone is dislocated in the dorsal, with loss of semilunar relationship – large bone.
In the anterior dislocations of the semilunar, the anterior basal plane of the semilunar is more or less marked with respect to the radial glenoid with “neo-articulation” radial-large bone. In the luxation trans-scaphoretrolunar fracture of the carpus, the proximal fragment of the scaphoid remains in solidarity with the semilunar, and the distal fragment remains solid with the rest of the carp. An associated fracture of the radial styloid is explained by a phenomenon of exhaustion of the traumatic force, hence the necessity to look for an intracarpian ligament lesion when this fracture is observed. 30% of perilunar dislocations of the carp are not known during the first assessment. To avoid these diagnostic errors, careful reading of carp bones and their relationship to the incidence of face and profile (middle column) should be considered. The reduction and stabilization treatment is surgical.
Compression of the median nerve is possible in the anterior dislocation of the semilunar. Remote risk is destabilization of the carp.
Anterior or posterior radiocarpal dislocations:
They are obvious clinical and radiological diagnosis: no change in carp bone ratios, and loss of radiocarpal contact with most often posterior displacement of carp. These dislocations are exceptionally isolated and are associated with anterior or posterior styloid and / or marginal fractures of the radius. The capsular state and the presence of intermediate fragments condition the surgical gesture and are better studied after traction. Anterior dislocations may compress the median nerve.
The wrist is not distorted:
The fracture of the scaphoid:
It is a frequent lesion. The trauma is usually a fall on the palm of the hand, wrist in hyper extension. Edema is unimportant. The pain is characteristic, sitting at the level of the anatomical snuffbox, increased to the pressure in the axis of the 1st metacarpal.
Radiocarpal mobility is normal.
I mageri e. The incidences of the face and of the profile of the wrist are compulsorily complemented by a specific incidence of the scaphoid (face located in semi-pronation or in cubic inclination). The line is transverse, usually at the level of the middle third. It may be more rarely polar higher or lower. The filling of the fat located below the radial styloid and facing the external surface of the scaphoid is an indirect sign of fracture of the scaphoid. These fractures often go unnoticed.
They may be the only evidence of a medocarp sprain.
One should not hesitate to carry out a control at 10 days after immobilization, or a CT in case of doubt on a fracture. In case of displacement in particular of plicature, the treatment is surgical. The risks at a distance are the evolution towards pseudarthrosis and osteonecrosis of the proximal segment.
The fracture of another carpal bone:
It is much rarer, often unrecognized and late discovery on traumatic post traumatic pain (TDM balance). In the initial assessment, specific effects must complement the face and profile images according to the clinical location of the painful spot (incidence of the pisiform, the hooked bone, etc.).
Wrist sprain:
It has a mechanism identical to that of perilunar dislocation and fracture of the scaphoid. Pain is increased during mobilization. The standard face, profile, and scaphoid images eliminate the existence of a fracture line. They may reveal a small osseous removal at the scaphoid, semilunar or pyramidal level, confirming the sprain. At distance, we can produce dynamic images in search of a yawn of the scapho-lunar or luno-pyramidal interlining.
The secondary evolution of these lesions may be towards secondary destabilization of the carpus.
Trauma of the Hand:
The lesions of the thumb are dissociated from lesions of the long fingers because of its additional function of opposition.
Attacks on 2nd, 3rd, 4th and 5th axes
The metacarpal fractures:
They are of high frequency and pose few diagnostic problems. There is deformation and edema, pain is localized, wrist mobility is normal.
On the face and oblique plates of the hand, the line of diaphyseal fracture is transverse or spiroid with sometimes an angulation. The fractures of the cervix (consequence of a punch) are sometimes meshed, with angulation and tilting of the head towards the palm. The importance of displacement can lead to surgical treatment.
A stroke at the level of the base should make search for a dislocation carpo-metacarpal.
Carpo-metacarpal dislocation of the fingers:
It is rare and often unrecognized radiologically. There is a distortion of the dorsal aspect of the hand, quickly masked by the edema. Wrist mobility is normal. On the incidence of face and on the oblique, the carpo-metacarpal intervals are not released. An incidence of the profile of the wrist is then necessarily realized, highlighting this dorsal dislocation of metacarpals in relation to the carpus. This dislocation may be of interest from the 2nd to 5th metacarpals, more commonly the 4th and 5th metacarpals. In this case, the association with a fracture of the base of the 4th and 5th metacarpals is frequent and should make think of seeking dislocation in case of apparently isolated fracture.
Diaphyseal fractures of proximal and intermediate phalanges:
Transverse, oblique or spiroid, they pose no diagnostic problems.
The fracture of the phalangeal crown by crushing:
It is frequent and does not pose a diagnostic problem.
It is necessary to look for a possible loss of bone substance.
The fracture of the base of the distal phalanx (P3):
It is mostly dorsal. The pain is local and is accompanied by an absence of extension of P3 on P2.
The finger is studied by an incidence of face and profile.
On the profile, the dorsal fragment of the base of P3 is all the more visible as it is moved. The trait is often not visible on the face incidence. This fracture is equivalent to a disintegration of the extensor tendon. If this lesion is neglected, it evolves towards the loss of the extension of P3 on P2, with a finger in a mallet. A palmar involvement is exceptional.
The sprains and dislocations of the phalanges:
They are frequent among sportsmen (hand and volleyball).
The images eliminate a fracture, sometimes revealing a bony removal.
The achievement of the first axis:
The fracture-dislocation of the 1st carpometacarpal joint:
It involves a fracture at the base of the 1st metacarpal and a distal dislocation of the distal segment. This is the fracture of the boxer (Bennett’s fracture). There is a projection of the 1st metacarpal with a narrowing of the first commissure.The adduction and opposition movements of the thumb are painful. On the specific incidence of face and profile of the first axis, the line is located at the base of the 1st metacarpal, with proximal displacement of the distal segment, in relation to the retraction of the muscles of the thumb. The proximal fragment is integral with the trapezium. There may be a dislocation of the metacarpal with respect to the trapezium, without fracture.
The fracture of P2:
It is most often associated with crushing, is clinically and radiologically evident.