Few structures of the human anatomy are as unique as the hand. The hand needs to be mobile in order to position the fingers and thumb. Adequate strength forms the basis for normal hand function. The hand also must be coordinated to perform fine motor tasks with precision. The structures that form and move the hand require proper alignment and control in order for normal hand function to occur.
Ligaments are an important feature in the hand. We take them for granted until an injury puts them out of commission. Then we realize just how important they are. Ligaments are tough bands of tissue that connect bones together. Two important structures, called collateral ligaments, are found on either side of each finger and thumb joint. The function of the collateral ligaments is to prevent abnormal sideways bending of each joint.
Other important ligamentous structures include the volar plates and flexor tendon pulleys. The volar plate is the strongest ligament in the fingers. This ligament connects the proximal phalanx (finger bone closest to the palm) to the middle phalanx on the palm side of the joint. The ligament tightens as the joint is straightened and keeps the proximal interphalangeal (PIP) joint from bending back too far (hyperextending). Finger deformities can occur when the volar plate loosens from disease or injury.
The tendons that move the fingers are held in place on the bones by a series of ligaments called pulleys. These ligaments form an arch on the surface of the bone that creates a sort of tunnel for the tendon to run in along the bone. To keep the tendons moving smoothly under the ligaments, the tendons are wrapped in a slippery coating called tenosynovium. The tenosynovium reduces the friction and allows the flexor tendons to glide through the tunnel formed by the pulleys as the hand is used to grasp objects.
In this special focus article on the hand and wrist, ligamentous injuries of the hand are reviewed. The authors performed a literature search for the last 18 months. Updated information on new treatment techniques is provided. Topics covered include: 1) thumb collateral ligament injury, 2) finger collateral ligament injuries, 3) volar plate injuries, 4) flexor pulley injuries, and 5) carpometacarpal (CMC) ligament.
Most of the time, only severe injuries will require surgery to repair or reconstruct torn or damaged soft tissue (ligamentous) structures described here. Conservative (nonoperative) care is more often the case. When making treatment decisions, the surgeon takes into consideration the patient’s age, severity of injury, and presence of other injuries (e.g., bone fractures, joint dislocations).
Nonoperative care for these ligamentous injuries is usually under the supervision of a hand therapist (occupational or physical therapist). Treatment is designed to reduce pain, restore motion, and improve function. The therapist may provide a custom-made (designed for each individual patient) splint when needed. Splinting has been shown to allow early active motion that protects the healing ligament while encouraging healing.
Surgery to repair or reconstruct the damaged soft tissues is advised when there is a partial or complete (avulsion) tear of the ligament away from the bone. Operative care is also required when the patient does not respond to conservative care and/or when joint instability persists.
New surgical techniques that have developed in the last few years include mini bone anchors. The authors review various types of these newer bone anchors (e.g., PushLock suture anchor) compared with conventional types of sutures used in these repairs. Sometimes ligaments tear so badly, they can’t be repaired. In such cases, a tendon may be used as a graft to lengthen the ligament enough to reattach it to the bone. If that fails, the joint controlled and stabilized by the ligament may have to be fused or replaced.
Volar plate injuries can be managed with good results when diagnosed early and treated by the hand therapist. But late recognition of these injuries may mean a poor prognosis without surgical intervention. The authors give a detailed description of current recommendations for surgical technique. This included a discussion of the type of incision to use, way to retract or pull back the connective tissue covering tendons, careful debridement or removal of scar tissue, sutures and fixation used, and postoperative care.
One other newer feature in treatment related to flexor pulley injuries is a pulley splint. This type of metal ring fits over the injured pulley and provides support during the two-week rest period needed for healing. Rock climbers and fastball pitchers experience this type of injury most often and can benefit from these new pulley splints.
In summary, this article brings surgeons up-to-date on the diagnosis and treatment of ligamentous injuries of the hand. Although conservative care is mentioned, the main focus is on surgical decisions and surgical techniques for each of the five types of injuries described.