Ligaments are strong bands of connective tissue that bind bone to bone, providing stability within the joints of the musculoskeletal system. An injury to the ligaments of a finger can cause long-term complications if not properly treated. The American Academy of Family Physicians states that permanent finger deformities are possible even with treatment. Knowing the signs of a torn ligament in the finger can help assure the patient will get care in an appropriate and timely fashion.
Joint Instability
Clinical examination of a torn finger ligament begins with the patient demonstrating her ability to flex and extend the finger. Collateral ligaments that support the sides of each joint stabilize the finger joints. The proximal interphalangeal joint, which is the first joint of the finger not directly connected with the hand, is most commonly affected by injuries to the collateral ligament. Such injuries are sometimes referred to as "jammed fingers." When a physician applies pressure to a joint that has suffered a ligament tear, she may find laxity in the joint that indicates a loss of integrity of the ligamentous fibers.
Hyperextension
The volar plate is a sturdy band of connective tissue that lies at the palm side of each proximal interphalangeal joint. It extends from the finger bone closest to the hand, also known as the proximal phalanx, to the middle finger bone, or middle phalanx. At its proximal end it is ligamentous, while its insertion in the middle phalanx is cartilaginous. This stabilizing structure can be partially or completely torn during an injury. It sometimes breaks off a chunk of bone with it. This is known as an avulsion fracture.
The volar plate prevents the joint from hyperextending, or bending excessively backwards. A rupture of the volar plate can result in hyperextension of the joint, and the bone can dislocate dorsally, meaning toward the back of the hand.
Pain and Tenderness
Injuries to the volar plate can cause pain located on the palm side of the proximal interphalangeal joint. Collateral ligament injuries also present with pain, along with bruising, tenderness and swelling of the joint, according to Dr. Shelain Patel of the department of trauma and orthopaedics at University College Hospital in London.
Finger Weakness
Patel notes that patients with a history of finger ligament injuries involving the collageral ligaments often report weakness in the affected appendages. Such weakness can interfere with the patient's ability to grasp small objects or perform manual tasks using the fingers.
References
- "Clinics in Sports Medicine"; Injuries of the Fingers and Thumb in the Athlete; Jeffrey J. Peterson, MD, Laura W. Bancroft, MD; 2006
- "Strategies in Trauma and Limb Reconstruction"; Collateral Ligament Injuries of the Metacarpophalangeal Joint of the Thumb"; Shelain Patel et al; April 2010
- American Academy of Family Physicians:Acute Finger Injuries: Part I. Tendons and Ligaments
