How is rectus diastasis diagnosed?

Diagnosis of Rectus Diastasis

Rectus diastasis is primarily diagnosed through clinical examination using a caliper or ruler to measure the separation between the rectus abdominis muscles along the linea alba. 1

Clinical Examination Technique

• The patient should be examined in a supine position with knees bent to relax the abdominal wall 2
• Ask the patient to perform a partial sit-up or head lift to activate the rectus muscles, making the diastasis more visible 2
• Measure the width of separation between the medial borders of the rectus muscles using a caliper or ruler at specific locations 1
• The measurement should be taken at the widest point of separation, typically at the level of the umbilicus 2
• A separation of 2 cm or more is generally considered diagnostic of rectus diastasis 3

Diagnostic Imaging

Imaging modalities can be used to confirm the diagnosis or when clinical examination is inconclusive:

• Ultrasound is the preferred first-line imaging technique due to its accessibility, lack of radiation, and ability to provide dynamic assessment during muscle contraction 2
• CT scan can provide detailed anatomical information and is particularly useful when planning surgical intervention or when concurrent hernias are suspected 2
• MRI offers excellent soft tissue contrast and can help differentiate between diastasis and other abdominal wall pathologies 2

Classification Parameters

The severity of rectus diastasis can be classified based on:

• Width of separation: Mild (<3 cm), moderate (3-5 cm), or severe (>5 cm) 1
• Location of the defect: Supraumbilical, umbilical, infraumbilical, or combined 2
• Presence of concurrent hernias: Umbilical or epigastric hernias often coexist with rectus diastasis 1

Differential Diagnosis

Important conditions to rule out during diagnosis include:

• Ventral hernias (umbilical, epigastric, or incisional) which may coexist with rectus diastasis 1
• Abdominal wall tumors or masses 2
• Post-surgical changes to the abdominal wall 2

Special Considerations

• In pregnant or postpartum women, measurements should be taken at least 6-8 weeks after delivery as some degree of spontaneous resolution may occur 3
• The diagnosis should include assessment of functional impairment, not just the anatomical separation 1
• Documentation should include measurements at multiple levels (supraumbilical, umbilical, and infraumbilical) for comprehensive evaluation 2

Clinical Pitfalls to Avoid

• Failing to distinguish between rectus diastasis and true hernia, which have different management approaches 2
• Not considering the functional impact of the condition beyond the cosmetic concerns 1
• Overlooking concurrent conditions that may contribute to symptoms (hernias, back pain, pelvic floor dysfunction) 3
• Relying solely on visual inspection without proper measurement 2

By following these diagnostic guidelines, clinicians can accurately identify rectus diastasis and determine the appropriate management strategy based on severity and associated functional impairment.