What Is Delayed Fracture Healing?
Delayed fracture healing occurs when a fracture does not heal within the expected period, despite appropriate immobilisation and treatment.
Clinically, it is defined as the absence of sufficient radiological evidence of bone healing after the normal recovery period has elapsed. This period varies depending on the bone involved and the patient’s age, but it generally ranges from three to six months.
Delayed healing occurs more frequently in fractures of the long bones, such as the tibia and radius, but it may also affect the femur or the spine. Risk factors include diabetes mellitus, smoking, osteoporosis, poor blood supply to the affected area, inadequate immobilisation and premature weight-bearing.
The main symptoms include persistent pain at the fracture site, tenderness on palpation and a feeling of instability. In many cases, patients report that they do not feel any improvement despite several months of recovery.
Key Characteristics of Delayed Fracture Healing
The underlying pathophysiology of delayed fracture healing is associated with inadequate vascularisation and local hypoxia at the fracture site. Without sufficient oxygenation, osteoblasts—the cells responsible for producing new bone tissue—cannot function effectively, causing the regenerative process to slow considerably or stop.
Delayed fracture healing represents an intermediate stage. When it is not treated promptly, it may progress to fracture non-union or incomplete healing, both of which may require more invasive treatment. Early identification and intervention are therefore essential.
Additional characteristics include reduced bone density at the ends of the fracture, which may be visible on imaging, and the patient’s inability to return to normal daily activities. The psychological burden associated with a prolonged recovery period may also be considerable.
Scientific Evidence
Scientific literature consistently supports the role of oxygenation as an important regulator of bone healing. Experimental and clinical studies have shown that local hypoxia is a major factor in delayed bone union, while restoring adequate oxygenation may reactivate the biological regenerative process.
Studies evaluating the use of hyperbaric oxygen therapy in patients with delayed fracture healing have reported improved radiological findings, reduced pain and accelerated callus formation.
Combining hyperbaric oxygen therapy with appropriate orthopaedic management—including stabilization, reduced weight-bearing or surgery where indicated—appears to produce the best results.
Hyperbaric Oxygen Therapy for Delayed Fracture Healing
Hyperbaric oxygen therapy may be incorporated into the management of delayed fracture healing as an adjunctive treatment. Its purpose is to address one of the main contributing factors: insufficient local oxygenation at the fracture site.
During each session, the patient breathes pure oxygen under increased atmospheric pressure, typically between 2 and 2.5 ATA. Under these conditions, the amount of oxygen dissolved in the blood plasma increases significantly, allowing it to reach areas with impaired or inadequate microcirculation—precisely where the healing process has slowed or become inactive.
The increased local oxygen supply stimulates osteoblast activity and supports collagen synthesis, which provides the structural foundation for new bone tissue.
At the same time, hyperbaric oxygen therapy stimulates the production of vascular endothelial growth factor (VEGF), promoting neovascularisation—the formation of new blood vessels that can provide a continuous and adequate blood supply to the affected area.
A typical treatment course consists of 20 to 40 sessions, depending on the severity of the delayed healing, the type of fracture and any coexisting medical conditions.
The patient’s progress is monitored at regular intervals using X-rays or computed tomography (CT), in close collaboration with the treating orthopaedic surgeon.