Impaired Fracture Consolidation

Main forms of pathology

In traumatology, bone regeneration disorders are typically divided into two successive stages that differ not only in duration but also in the nature of the process:

• Delayed union. This occurs when the bone has not healed within a time frame twice as long as the average normative period for a specific type and localization of fracture. The regeneration process is not completely halted, but proceeds extremely slowly.
• Nonunion (pseudoarthrosis). This is a persistent impairment of bone integrity that is irreversible without surgical intervention. The fragments retain pathological mobility. The main diagnostic criterion distinguishing this stage is the formation of a terminal plate—the medullary canal is completely closed by fibrous or bone tissue. As a rule, this picture is observed 9–10 months after the initial fracture.

Etiology: why bones fail to heal

The causes leading to impaired reparative osteogenesis are divided into local (occurring directly in the injury zone) and general. Local factors are significantly more common in clinical practice.

Local causes include:

• Errors in reposition and fixation: inaccurate alignment of fragments or insufficient immobilization allowing for their mobility. This also includes overstretching of bone fragments due to improperly applied skeletal traction.
• Soft tissue interposition: entrapment of muscles or fascia between the fragments. If the interposition is partial, it provokes delayed union. If it is complete, it inevitably and always leads to the formation of a pseudoarthrosis.
• Bone tissue defects resulting from surgical resection or removal of freely lying fragments.
• Trophic disorders associated with massive soft tissue damage, compression or rupture of nourishing blood vessels and nerve trunks.
• Infectious complications, primarily osteomyelitis of the fragments in the fracture zone.

General causes are associated with overall bodily exhaustion and a decrease in its regenerative potential. These include advanced age, cachexia, poor nutrition, severe infectious processes, as well as systemic metabolic diseases (e.g., diabetes mellitus).

Principles of treatment

The choice of treatment strategy depends directly on whether the bone retains the ability to heal independently.

Management of delayed union Is predominantly conservative in nature. The main task is to ensure absolute rest for the fracture zone and stimulate callus growth.

1. Immobilization: a plaster cast or compression devices are used. Fixation must be meticulous and last precisely as long as necessary for a fresh fracture to heal. If the position of the fragments is unsatisfactory when using devices, surgical removal of the scar tissue between them followed by precise alignment is permitted.
2. Stimulation of regeneration: includes physical therapy (exercise therapy), massage, physiotherapy (calcium ion electrophoresis), and the administration of anabolic steroids against the background of a full, balanced diet.

Treatment of pseudoarthrosis Always requires exclusively surgical intervention. Conservative measures are ineffective when the medullary canal is closed.

During the surgery, the surgeon performs the following steps:

• Excises all dense scar tissue between the bone fragments.
• Refreshes the ends of the fragments (removal of the terminal plate).
• Mandatorily opens and recanalizes the medullary canals to restore normal blood circulation and bone marrow egress.
• Meticulously aligns the prepared fragments.

For subsequent reliable fixation, compression osteosynthesis devices or bone autografts are used, providing both mechanical strength and biological stimulation of osteogenesis.

Class and exam questions

What else to study on this topic

• Pathophysiology of terminal plate formation in pseudoarthrosis
• The impact of diabetes mellitus and cachexia on the cellular mechanisms of osteogenesis
• Types of bone autografts used in the treatment of nonunions
• Biomechanics of compression osteosynthesis in the treatment of healing impairments
• Mechanism of action of anabolic steroids on bone tissue regeneration

Other topics in "CHAPTER 10. GENERAL ISSUES IN TRAUMATOLOGY"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.