Lower Extremity Malalignment (Malunion)

What is Lower Extremity Malalignment (Malunion)?

Lower extremity malalignment, also known as malunion, refers to the improper healing of a bone in the lower limb (such as the femur, tibia, or fibula) after a fracture. When a bone breaks, it typically undergoes a healing process where the broken ends come together and fuse. However, if these ends do not align properly during healing, it can result in malunion. This malalignment can lead to various issues such as altered gait, joint pain, and uneven weight distribution, affecting overall function and mobility.

Causes of Lower Extremity Malalignment (Malunion)

Lower extremity malalignment, or malunion, can result from various causes, including:

• Non-union of fractures
• Delayed healing of fractures
• Improper healing of fractures
• Inadequate immobilization of the fractured bone during the healing phase
• Improperly applied casts, splints, or fixation devices
• Bone defects such as osteoporosis
• Severe trauma or multiple fractures in the same area
• Bone infections such as osteomyelitis that can interfere with the normal healing process
• Underlying conditions such as congenital deformities, metabolic disorders, or neuromuscular conditions

Signs and Symptoms of Lower Extremity Malalignment (Malunion)

Lower extremity malalignment or malunion can lead to various signs and symptoms, such as:

• Deformity: The bone may heal in a crooked or angled position, leading to visible deformity.
• Functional Impairment: Malalignment can affect the normal function of the limb, causing problems with walking, running, or other activities.
• Joint Problems: Improper alignment can put stress on nearby joints, leading to arthritis or other joint-related issues.
• Pain: Malalignment can cause chronic or intermittent pain in the affected limb.
• Instability: Malalignment can compromise the stability of the affected limb.
• Muscle Imbalance: Malunion can also cause muscle imbalances, as muscles may need to work differently to compensate for the misaligned bone.

Diagnosis of Lower Extremity Malalignment (Malunion)

Diagnosing lower extremity malalignment, specifically malunion resulting from a previous fracture or injury, typically involves a combination of diagnostic components, such as:

• A review of your medical history including any previous fractures, surgeries, or relevant medical conditions
• A thorough physical examination to assess the affected limb's alignment, range of motion, strength, and presence of any visible deformities or abnormalities
• Imaging studies, such as:
  • X-rays to evaluate bone alignment and detect any malunion
  • CT scans for more detailed imaging of the affected limb to assess the extent and nature of malunion more accurately
• Gait analysis to identify abnormalities in gait mechanics, weight distribution, and compensatory movements

Treatment for Lower Extremity Malalignment (Malunion)

The treatment for lower extremity malalignment (malunion) depends on various factors such as the severity of malalignment, the location of the malunion, the patient's symptoms, and functional limitations. Common treatment options for lower extremity malalignment due to malunion include:

Conservative Management:

• Monitoring: In some cases, especially if the malalignment is mild and does not cause significant symptoms or functional limitations, conservative management with regular monitoring may be sufficient.
• Physical Therapy: Physical therapy plays a crucial role in improving strength, flexibility, and gait mechanics. Therapeutic exercises, stretching, and functional training can help optimize function and reduce symptoms associated with malalignment.
• Orthotic Devices: Custom orthotic devices such as shoe inserts, braces, or orthopedic footwear may be prescribed to provide support, correct alignment, and reduce pressure on affected joints or areas.

Surgical Interventions:

• Osteotomy: Surgical correction of malunion often involves osteotomy, which is the surgical cutting and realignment of the bone to restore proper alignment. Various techniques, such as closing wedge osteotomy, opening wedge osteotomy, or rotational osteotomy, may be used based on the specific nature of the malunion.
• Internal Fixation: In cases where stability is a concern, internal fixation devices such as plates, screws, or intramedullary nails may be used to stabilize the bone after osteotomy or to correct malalignment directly.
• External Fixation: External fixation devices, such as external fixators or Ilizarov frames, may be utilized in complex cases or when gradual correction of malalignment is needed over time.

Postoperative Rehabilitation:

• Physical Therapy: Following surgical intervention, a structured rehabilitation program is essential for optimal recovery. Physical therapy focuses on restoring range of motion, strength, coordination, and functional abilities.
• Weight-Bearing Progression: Gradual progression of weight-bearing activities is typically guided by the surgeon and physical therapist to ensure proper healing and adaptation of the corrected alignment.