Introduction
The wrist has often been described by surgeons as a “black box”, in that for a long period of time in hand surgery the pathology and mechanics were not well understood. In fact, most of these injuries were treated by surgeons who did not have specialized training in wrist conditions. It is only recently that it has come to be appreciated that the wrist should be considered in concert and as part of the hand and requires a hand surgeon who has extensively studied and trained in this part of the upper extremity.
Before addressing specific wrist injuries and pathology it is important to have at least a basic understanding about the function of the wrist, its anatomy, mechanisms of injury, as well as, initial evaluation and treatment. These building blocks serve as the basis for more in-depth study.
This month’s Hand Surgery Update will serve as an introduction to a series of articles which will be presented over the following months on specific wrist injuries and conditions. Please be patient are there are numerous areas to discuss as books have been written which focused exclusively on wrist conditions, some of which have extended to two volumes.
As always we welcome your feedback and suggestions for future topics in hand and wrist surgery. Please share this article with friends and colleagues as we are certain that this is and will be a topic that garners great interest.
Background
The wrist is the critical link between the arm and fingers that permits fine adjustments to the position of the hand in space. This ability to precisely position the hand allows us to accomplish a variety of manual tasks with skill and ease. Injuries to the wrist disrupt the link and lead to decreased hand function. Proper evaluation and management of wrist injuries is essential in order to optimize recovery and minimize loss of hand function.
Anatomy
The wrist is a complex structure formed by eight carpal bones, the radius, the ulna, and an intricate network of ligaments. The carpal bones are divided into two rows. The proximal carpal row includes the scaphoid, lunate, triquetrum, and pisiform. The distal carpal row includes the trapezium, trapezoid, capitate, and hamate.
The network of ligaments in the wrist includes both intrinsic and extrinsic ligaments. Intrinsic ligaments connect the carpal bones to each other. Extrinsic ligaments connect the carpal bones to the radius, ulna, or metacarpal bones. One of the most important intrinsic ligaments is the scapholunate ligament that connects the scaphoid to the lunate bone. Another important ligament is the triangular fibrocartilage complex or TFCC. Both the scapholunate ligament and the TFCC are critical to proper wrist function.
Function
The first critical function of the wrist is motion.
Wrist movements include:
- Flexion
- Extension
- Radial deviation
- Ulnar deviation
- Pronation (turning the hand palm down)
- Supination (turning the hand palm up)
The second critical function of the wrist is load bearing. Forces are transmitted across the wrist joint during a variety of tasks. For example, formation of a tight fist during gripping activities transmits high forces across the wrist joint.
Mechanism of Injury
Perhaps the most common mechanism for wrist injury is a fall onto an outstretched hand or FOOSH. However other mechanisms include loaded twisting, hyperextension, and direct blows to the wrist.
Evaluation
Physical examination and radiographic evaluation are two essential components of the work-up of a patient with an acute wrist injury.
Physical exam begins with inspection for swelling, bruising, or deformity. Next, the wrist and hand are palpated to elicit tenderness. Tenderness to palpation or pain with provocative maneuvers can localize the injury to a specific anatomic structure.
Radiographic examination at the time of injury is indicated for patients with any deformity, significant soft tissue swelling, or pain that localizes to a specific anatomic area. A three view wrist x-ray series of the wrist includes the PA, lateral, and oblique views. Plain x-rays properly obtained will detect most fractures and dislocations, but do not provide information about soft tissue injuries. If plain radiographs are negative and the patient has significant localized pain, MRI may be appropriate in the acute or chronic setting.
Treatment
The treatment of wrist injuries is tailored to the severity and type of injury.
Wrist sprains are among the most common wrist injuries. A wrist sprain is a stretching or tearing of the ligaments of the wrist. Initial management consists of rest, ice, compression, elevation, and immobilization. Many wrist sprains will resolve within 1-3 weeks without any further intervention. However, a wrist sprain can result in severe damage that requires prolonged splinting, a trial of corticosteroid injection or eventual surgical intervention. If a patient with a wrist sprain has persistent symptoms 4 weeks after injury or pain that localizes to a specific area, referral to a wrist specialist is indicated.
Fractures of the carpal bones, distal ulna, and distal radius are treated with immobilization or operative fixation as indicated. Immobilization typically will be for a period of six to eight weeks. Hand therapy is an essential component of treating wrist injuries. The purpose is the acute setting is to reduce edema and maintain digital (finger) motion and is typically initiated within the first several weeks. Wrist motion is initiated after fracture healing is achieved.
Treatment protocols must be individualized and outcomes vary according the severity and location of the fracture. In our opinion treatment by a hand surgeon who has specialized in wrist surgery results in a more satisfactory outcome.
Conclusion
As we said, this article serves as only an introduction to the topic of wrist injuries. We hope you find the coming updates educational and informative.
Information provided by: Hand & Plastic Surgery Associates, Ltd. – The physicians of HPSA treat the most challenging and complicated hand and wrist problems as well as minor conditions and injuries. They believe that seeing a physician who specializes in surgery of the hand yields the best results. When caring for injured workers, HPSA takes a proactive role to insure that these individuals are returned to work as soon as medically possible. They assist employers and case managers in determining appropriate job placement. Their physicians are also available for independent medical evaluations and second opinions. Visit their website at www.handplastic.com to learn more about HPSA.
