Stener lesion

A type of injury to the thumb's ulnar collateral ligament

Overview

A Stener lesion is a specific type of injury that occurs in the thumb, involving the ulnar collateral ligament (UCL) of the metacarpophalangeal joint. This injury is characterized by the displacement of the torn ligament, which becomes trapped above the adductor aponeurosis, preventing proper healing and leading to chronic instability if not treated appropriately.

Anatomy

The ulnar collateral ligament is a critical stabilizer of the thumb's metacarpophalangeal joint. It is located on the ulnar side of the joint and is responsible for resisting valgus stress. The adductor aponeurosis is a fibrous structure that covers the UCL and the adductor pollicis muscle.

Pathophysiology

A Stener lesion occurs when the UCL is completely torn and the distal end of the ligament is displaced superficially to the adductor aponeurosis. This displacement prevents the ligament from healing in its anatomical position, leading to persistent instability of the thumb joint.

Clinical Presentation

Patients with a Stener lesion typically present with pain, swelling, and instability of the thumb following an acute injury, often due to a fall or a direct blow to the thumb. The inability to pinch or grasp objects firmly is a common complaint.

Diagnosis

The diagnosis of a Stener lesion is primarily clinical, supported by imaging studies. Ultrasound and magnetic resonance imaging (MRI) are useful in confirming the displacement of the UCL.

Ultrasound image showing a Stener lesion

Treatment

Surgical intervention is typically required to correct a Stener lesion. The procedure involves relocating the displaced ligament and securing it in its anatomical position, often using suture anchors. Postoperative rehabilitation is crucial for restoring function and strength.

Prognosis

With appropriate surgical treatment and rehabilitation, most patients regain full function of the thumb. However, delayed treatment can lead to chronic instability and arthritis.

Related pages

• Ulnar collateral ligament injury of the thumb
• Metacarpophalangeal joint
• Adductor pollicis muscle