Ulna fracture is a violation of the integrity of the ulna as a result of traumatic exposure. It can be combined with dislocation of the radius or be isolated. Pathology is manifested by sharp pain, swelling, impaired movement. With fractures, there is shortening and deformation of the forearm, as well as pronounced restriction of movements in the elbow joint. To confirm the diagnosis, radiography is performed, less often – CT. Treatment can be conservative (reposition, immobilization with a plaster cast) or operative (fixation with a knitting needle, suture or plastic of the annular ligament).
S52.2 Ulna fracture
Ulna fracture in clinical traumatology is diagnosed relatively rarely, fractures of both forearm bones are more common. Isolated injuries, as a rule, are not accompanied by a pronounced displacement and proceed quite favorably. When an ulna fracture is combined with other injuries of the forearm and elbow joint, the course is more severe, significant displacement and nerve damage is possible, surgical treatment is more often required.
Usually injuries occur in everyday conditions and during sports activities. Some patients have a history of criminal incidents involving the use of sticks, batons, iron rods, etc.
Isolated ulna fracture can occur in people of any gender and age, the cause is usually a direct blow to the forearm.
Damage to the Monteggi (fractures of the upper third of the ulna in combination with dislocation of the beam head) are more often observed in young and middle-aged men who are actively involved in sports, formed when falling on the arm or during a defensive movement when a person tries to deflect a blow with a bent arm.
In children, a Monteji fracture is often formed as a result of a direct blow to the inner surface of the elbow joint.
An isolated fracture, as a rule, is located in the lower third, is transverse, so the fragments are well held and rarely displaced. The displacement along the axis and along the length is uncharacteristic, since the correct position of the fragments is preserved thanks to the whole radius. In some cases, there is an angular displacement, which necessarily requires elimination, since in the future it can negatively affect the function of the forearm.
Damage to the Monteggi is a high-energy injury. With such fractures, the fragments of the ulna are displaced, and the forearm is shortened, as a result of which the head of the beam is dislocated in the proximal ray-elbow joint. Such injuries require mandatory reposition, otherwise, in the long-term period, a deformity of the forearm is formed, a violation of the function of the elbow joint is noted.
There are isolated ulna fracture without displacement and with displacement of fragments. Monteggi fractures are always accompanied by displacement, depending on the nature of the injury, orthopedic traumatologists distinguish four types of injuries:
- 1 – the head of the beam is dislocated anteriorly, bone fragments form an angle open anteriorly.
- 2 – the head of the radius is dislocated posteriorly, the fragments form an angle open posteriorly.
- 3 – the head is dislocated laterally, the ulna is damaged in the proximal part.
- 4 – the head is dislocated anteriorly, there is a fracture of the proximal parts of both forearm bones.
Isolated ulna fracture
With an isolated injury, the patient complains of sharp local pain. The area of damage is edematous, sometimes deformed. Hemorrhages are possible. Movements are limited due to pain, the function of the forearm is usually moderately impaired, active extension and flexion of the elbow joint, supination and pronation of the hand are carried out in a small volume, rotation disorders are most pronounced.
Palpation of the injury zone is sharply painful, when feeling the rib of the bone in the case of a fracture with displacement, a “ledge” is determined. Pathological mobility is not always detected during a careful examination, it is not recommended to perform intensive manipulations to detect this sign in order to avoid secondary displacement. The axial load is painful.
The elbow joint and forearm are swollen, deformed, bruising is possible. The swelling is rapidly increasing. A comparative examination reveals some shortening of the forearm on the side of the injury. With posterior dislocations, it is sometimes possible to determine the displacement of the beam head by palpation. In the area of the ulna fracture, a “step” or “ledge” is felt, which arose due to the displacement of fragments.
There are no active movements, and when passive movements are attempted, spring resistance is detected. The points of greatest pain are determined in the projection of the beam head and in the area of violation of the integrity of the bone. With pressure along the axis of the limb, pain occurs in the projection of the fracture. Crepitation is possible.
Complications are not typical for isolated injuries. Rarely, in the presence of an untreated displacement, there is an indistinctly pronounced deformation of the forearm, a slight limitation of limb functions. With Monteggi fractures, concomitant vascular and neurological disorders are often observed, especially damage to the radial nerve, accompanied by a disorder of movements and sensitivity in the innervation zone.
Sometimes, with damage to the Monteggi, a compartment syndrome develops, due to an increase in subfascial pressure as a result of pronounced edema of the limb. Signs of such a syndrome are increasing persistent pains, pain when pulling on fingers and increased tension in the forearm area. After bone fusion, in the presence of these complications, disorders of the functions of the forearm are possible, which cause disability.
Diagnosis of ulna fracture is carried out by a traumatologist. In the process of diagnostic search, anamnesis data, examination results and instrumental studies are used. The examination program includes the following procedures:
- Objective inspection. Edema is detected, hematomas, deformity of the limb are possible. Pathognomonic signs of a fracture are bone crunch, the presence of a “step” in the area of damage. The dislocation of the beam head is indicated by the characteristic deformation, spring resistance during passive movements.
- Radiography. It is the main instrumental method. To clarify the diagnosis of isolated fractures, radiography of the forearm is prescribed in two projections. In case of fractures of the Monteggi, an X-ray of the forearm is performed with the capture of the elbow and wrist joint, using two standard and oblique projections.
- Other visualization techniques. They have an auxiliary value for injuries of the ulna. Sometimes a CT scan of the bone is prescribed to detail damaged structures, and an MRI is used to study the condition of soft tissues.
If a Monteggi fracture is suspected, attention is paid to the presence of neurovascular disorders, the pulse on the radial and ulnar arteries is evaluated. If signs of nerve or vessel damage are detected, consultations of a neurologist or a neurosurgeon and a vascular surgeon are prescribed.
Treatment of an isolated fracture
In the absence of displacement, outpatient treatment is possible. With the displacement of bone fragments, hospitalization in the traumatology department is indicated.
- Conservative treatment. In case of damage without displacement, ordinary or polymer plaster is applied for 6-10 weeks. If there is an offset, a reposition is performed, a control snapshot is taken after 10 days, the plaster is preserved for 10-12 weeks.
- Surgical interventions. Operations are performed when the reposition is unsuccessful and it is impossible to keep the fragments in the correct position. Osteosynthesis of the diaphysis of the ulna is carried out with a plate or pin. Immobilization also lasts 10-12 weeks.
In the postoperative period, antibiotic therapy is prescribed, UHF, analgesics, antibiotics, exercise therapy and massage are used. The stitches are removed after 8-10 days, then the patient is discharged for outpatient treatment.
Treatment of a Monteji fracture
The patient is hospitalized in a trauma hospital, a closed reposition is performed.
- In case of extensor injuries, transarticular fixation using a thin spoke is sometimes performed to prevent repeated dislocation.
- With flexion fractures, fixation of the head with a spoke is usually not required.
Plaster is applied, a control radiography is done, an elevated position is given to the limb to reduce swelling (the arm is placed on a pillow or suspended from a special stand), physiotherapy procedures are prescribed. The removal of the spokes is carried out after 2-3 weeks. After 4 weeks, the plaster is replaced by changing the position of the limb. Immobilization is stopped after 8-12 weeks.
Surgical treatment is more often required for extensor type of fracture. Osteosynthesis of the diaphysis of the ulna is performed with a pin and the suture of the annular ligament. If the ligament cannot be stitched, plastic surgery is performed using an autograft cut out of the patient’s fascia. The beam head is adjusted and fixed with a spoke.
In case of neck fractures, resection of the beam head is performed, in such cases, a suture of the annular ligament is not required. In some cases, auto- or homotransplants (small plates of spongy bone) are applied to fragments of the ulna to accelerate fusion. The wound is being stitched up. After the operation, physiotherapy, massage, physical therapy are prescribed. Immobilization is carried out within 3 months.
In children, the operative tactics are the same as in adults, the only difference is that they try to avoid resection of the head with any kind of injury, since this can negatively affect the growth of the radius and the function of the forearm.
With isolated fractures, the prognosis is usually favorable. Damage to the Monteggi belongs to the category of complex fractures that are difficult to treat and are often complicated by a violation of limb function. In the early period, non-fusion or delayed fusion of the ulna is often observed in adults, due to a lack of soft tissues on the ulnar side of the forearm.
The outcome may be an angular curvature or displacement of the head of the radius. Sometimes synostoses (splices) form between the radial and ulna bones, which result in restriction of rotational movements. There may also be subluxations and dislocations of the head of the ulna in the area of the distal radiocarpal joint.
Prevention involves taking measures to reduce the level of injuries. It is necessary to observe safety precautions when performing various works at home and at work, playing sports, equipping playgrounds with the use of non-traumatic materials. Measures to reduce the number of criminal incidents (fights) play a certain role.