Sagittal band injury is a common yet often under-recognized condition affecting the extensor mechanism of the fingers. The sagittal bands are crucial stabilizers of the extensor tendons at the level of the metacarpophalangeal (MCP) joints, and injury to these structures can lead to pain, swelling, and dysfunction of finger extension. Understanding the anatomy, causes, clinical presentation, diagnosis, and treatment options for sagittal band injuries is essential for timely management and restoration of hand function.
The sagittal bands are fibrous structures that form part of the extensor hood mechanism on the dorsal aspect of the fingers. Each finger has two sagittal bands (radial and ulnar), which originate from the volar plate and the deep transverse metacarpal ligament and insert into the extensor tendon and the base of the proximal phalanx.
Their primary function is to centralize and stabilize the extensor digitorum communis (EDC) tendon over the MCP joint during finger flexion and extension. By anchoring the extensor tendon, the sagittal bands prevent subluxation or dislocation of the tendon, ensuring smooth and coordinated finger movements.
Sagittal band injuries typically occur due to trauma or repetitive stress. The most common mechanism is a direct blow to the dorsal MCP joint or forceful flexion of the finger while the extensor tendon is taut. This can cause partial or complete rupture of the sagittal band, leading to instability of the extensor tendon.
Sagittal band injuries are classified based on the extent of damage and tendon displacement:
Patients with sagittal band injury typically present with:
The middle finger is most commonly affected, followed by the index and ring fingers.
Diagnosis of sagittal band injury is primarily clinical but can be supported by imaging studies.
Treatment depends on the severity and chronicity of the injury.
Rehabilitation after sagittal band injury treatment focuses on:
Potential complications of sagittal band injury and its treatment include:
With appropriate treatment, most patients regain good function of the affected finger. Early diagnosis and management improve outcomes and reduce the risk of chronic deformity or disability.
Sagittal band injury is a disruption of the fibrous bands stabilizing the extensor tendons at the MCP joints, leading to pain, swelling, and extensor tendon instability. It commonly results from trauma or repetitive stress and is most frequently seen in the middle finger. Diagnosis is clinical, supported by imaging such as ultrasound or MRI. Treatment ranges from splinting and physical therapy for mild injuries to surgical repair for severe cases. Rehabilitation is crucial for restoring function, and prognosis is generally favorable with timely intervention.