A fracture that has difficulty healing requires surgery. But sometimes consolidation gives rise to complications, including pseudoarthrosis. What are the risk factors for pseudarthrosis? When and how is it practiced? Update with Doctor Olivier Fontes, orthopedic surgeon at the Clinique du Parc in Castelnau-le-Lez.
Definition: when to talk about pseudarthrosis?
Pseudarthrosis is a late complication of fractures manifested by a lack of union between two bone fragments.
Pseudarthrosis concerns fractures of all the long bones of the body (arms, forearms, legs). The spine can also be the site of a pseudarthrosis.
Types of nonunion
There are two types of pseudarthrosis: tight nonunion or atrophic pseudarthrosis and hypertrophic pseudarthrosis.
“Five to 10% of all fractures show delayed union, while 1 to 5% progress to nonunion, which can be defined as a fracture more than six months old and which is unlikely to heal without additional intervention. “, indicates the Swiss Medical Review.
Bone consolidation and risk of malunion
Consolidation in an abnormal position of a bone after a fracture is called malunion. “Pseudarthrosis is therefore a fracture which does not consolidate despite orthopedic treatment, that is to say the placement of a cast or the installation of osteosynthesis material (plate screwed to the ends in steel or titanium on the fracture )”specifies Doctor Olivier Fontes, orthopedic surgeon at the Clinique du Parc in Castelnau-le-Lez.
Duration of pseudarthrosis
Pseudarthrosis is declared beyond 6 months for the lower limbs up to 8 or 9 months for the upper limbs.
Abnormality of fracture consolidation. Why doesn't a fracture heal?
In the fracture process when a bone breaks in two, a hematoma is produced which will form around the fracture site. This hematoma will provide all the substances necessary for the bone to consolidate. Immobilizing the bone segment with a cast prevents movement and promotes consolidation. But if a calcification defect occurs, there will still be movement between the bone fragments. This is called pseudarthrosis.
What are the causes of pseudarthrosis?
Aseptic pseudarthrosis
There is no infection and its cause is probably mechanical (such as a lack of immobilization or long-term micro-movements in the fracture site). “The open fracture due to the loss of the peri-fractural hematoma has a higher risk of non-union and is not necessarily of infectious origin.indicates the doctor.
Septic pseudarthrosis
It takes place in the context of surgical treatments which have become infected, particularly in cases of open fracture where the risk of infection is greater.
Failure to immobilize
This is another factor in nonunion. The surgeon may have immobilized the fracture in a non-optimal manner (due to its complexity) or the patient made a movement that he should not have made during the healing period. “For example, it is not recommended to resume walking 3 days after the plaster is placed, whereas it is recommended to wait 45 days. indicates the surgeon.
Surgery
Surgery is also another risk factor, more precisely if osteosynthesis material is placed on an open fracture. “On the tibia, the femur, the humerus, we prefer to place a rod in the bone which allows us to preserve the fracture hematoma and increase the chances of consolidation. explains the doctor.
Age does not play a role in the risk factors. “Osteoporosis does not play a role in the consolidation of the fracture but rather on the fragility of the bone”, recalls Doctor Olivier Fontes. “We should also not confuse “pseudarthrosis”, which is the non-union of a fracture beyond a certain period of time, with “delayed consolidation” which rather designates consolidation which takes a long time but which, ultimately, will consolidate”, would like to clarify the orthopedic surgeon. “The X-ray images show that there is always a delay in consolidation just after removing the cast. So be patient. This is completely normal.”
What are the symptoms of pseudarthrosis?
When the resin cast is removed, there may be some pain and this is completely normal. But if the pain symptom persists, does not subside, if the patient limps, cannot place his foot on the ground because it hurts too much (in the event of a fracture in a lower limb), cannot move his upper limb or hears a clicking sound (of both fragments), it may be a pseudarthrosis. Decalcification makes the bone more susceptible to fractures.
In the event of infection, fistulas may appear near the fracture site.
How to diagnose a pseudarthrosis?
The diagnosis is made on the clinical aspect and radiographic imaging and in case of doubt the general practitioner uses other imaging examinations such as CT scan.
How do I know if my bone is consolidated or not?
The orthopedic surgeon or general practitioner can diagnose pseudarthrosis by palpation of the bony callus (tibia, clavicle, humerus). “If it is painful, there is indeed a delay in consolidation.confirms Doctor Olivier Fontes.
What treatment in case of pseudarthrosis in case of complications? How to cure pseudarthrosis?
The surgical operation
Treatment is most often surgical. If the orthopedic treatment (casting) has not allowed bone consolidation, the surgeon operates. “The treatment technique consists of sharpening the fracture site by decorticating it with small bone scissors. indicates the surgeon. “We are going to make chips all around to stimulate vascularization and recreate a bone callus. We then fix the bone segments at the ends using osteosynthesis equipment (intramedullary with a nail, screwed plate, etc.)”. The duration of hospitalization varies depending on the difficulty of each case, such as for scaphoid fracture.
Bone grafting
It is also possible to perform a bone graft with an external bone supply. This is the case if there are many fragments. “What works best is autograft.” confirms the doctor. “With a sample from the pelvis or fibula”.
In terms of treatment, there are also allografts. The bone is taken from the neck of the femur in another person after a hip prosthesis has been fitted.
Then, there are bone substitutes, osteo-inductive substances such as hydroxy apatite (these substances will stimulate bone production) or bone replacement matrices.
Treatment requires prolonged immobilization. Monitoring will consist of a clinical examination and radiographic monitoring at one and a half months, 3 months, 6 months in order to verify that the fracture is consolidating normally.
The patient generally convalesces at home. If several segments are affected, convalescence will be taken care of in a rehabilitation center.
“20 years ago the low-intensity pulsed ultrasound bracelet technique was practiced,” informs us Doctor Olivier Fontes. “It was used when no solution had worked (bone grafts). But today, despite encouraging results, this technique is no longer relevant because it is no longer reimbursed by the Health Insurance Fund and remains very expensive.
