malunions

Malunion is the proper healing of a fracture in a misaligned position, resulting in deformity, limb length discrepancy, or rotational malalignment. It differs from nonunion, where healing fails to occur. Malunions most often affect long bones such as the tibia, femur, radius, and ulna, but can involve any bone.

Causes include inadequate reduction or fixation at injury, premature weight bearing, and poor healing conditions such as infection, compromised blood supply, smoking, osteoporosis, or metabolic disorders. Fracture pattern (high-energy, comminuted) and soft-tissue injury also influence the likelihood of malunion.

Clinically, malunion presents with deformity, pain on use, reduced function, and sometimes limb-length discrepancy. Imaging with X-rays in multiple views assesses angular, translational, and rotational deformities; CT may help characterize complex rotational malunions.

Treatment is tailored to deformity, symptoms, and functional demands. Corrective osteotomy with internal fixation or external fixation, often with bone grafting and sometimes limb-length adjustment, is standard. Rehabilitation aims to restore motion and strength. Prognosis is generally good after accurate correction, but risks include persistent pain, stiffness, infection, or recurrence. Prevention centers on accurate initial reduction and stabilization and avoidance of smoking.