Hand and wrist injuries are common in athletes, making up between 3% and 9% of all athletic injuries. Athletic injuries to the hand and wrist can range from simple sprains to severe fractures. Many injuries of the hand and wrist are obvious, but subtle injuries can be missed and may require a high index of suspicion with a systematic examination and diagnostic imaging. Often injuries to the hand and wrist may be dismissed as trivial; however, delay in diagnosis and treatment may lead to significant and possible permanent disability. Overtreatment or inappropriate treatment can be just as problematic. Swanson appropriately said, “Hand fractures can be complicated by deformity from no treatment, stiffness from over-treatment, and both deformity and stiffness from poor treatment.”¹ In this chapter, we will discuss the diagnosis, treatment, and rehabilitation of common hand injuries to the athlete.

A basic understanding of the complex anatomy of the finger, hand, and wrist is necessary to properly diagnose and treat acute injuries. There are 27 bones that act dynamically to allow oppositional grip: eight carpal bones, five metacarpals, and fourteen phalangeal bones. In general, the radial nerve accounts for wrist and finger extension, the ulnar nerve provides finger flexion on the ulnar side and power grip, and the median nerve provides thumb opposition and circumduction to allow for fine control. Vascularity to the hand is provided by the radial and ulnar arteries, which join together in the palm to make up the deep and superficial palmar arches. Each digit has two neurovascular bundles, which travel volarly on both the radial and ulnar aspects of the digit.

Bony anatomy of the hand includes the five metacarpals, with first, fourth, and fifth metacarpals having increased mobility at their corresponding carpometacarpal (CMC) joints. In contrast, the second and third metacarpals are held rigid at the CMC joint by stout ligaments and congruent articulation with the trapezoid and capitate. The transverse metacarpal ligaments interconnect the second through the fifth metacarpals adding to their internal support. The thumb metacarpal is positioned on the trapezium in an abducted and pronated position to allow for its prehensile function.

Each finger is an individual skeletal unit made up of a proximal, middle, and distal phalanx (Fig. 15.1A). The proximal and middle phalanges can be divided into the base, shaft, neck, and head, whereas the distal phalanx has a base, shaft, and tuft. There are three ginglymus (hinged) joints in each finger: distal interphalangeal (DIP), proximal interphalangeal (PIP), and metacarpophalangeal (MCP). The interphalangeal (IP) joints in the fingers are bicondylar, providing a great arc of motion as well as bony stability for lateral and rotatory forces. The collateral ligaments, volar plate, and extensor mechanism offer additional stability to the joint, and injury to these structures may compromise function significantly. The thumb CMC joint is unique with its reciprocally biconcave saddle joint allowing for opposition with the other digits.² The thumb is made up of the first metacarpal and only two phalanges with a single IP joint.

The most complex anatomy of the hand includes the extensor mechanism of the fingers. The extensor digitorum communis (EDC) splits into four separate tendons, one to each finger. As the extensor tendon passes over the MCP joint, there is some adhesion to the joint capsule, but no formal insertion. The tendon is anchored over the MCP joint by the sagittal bands that arise from the volar plate. In addition to keeping the extensor tendon centralized over the MCP joint, sagittal bands also function to extend the proximal phalanx. At the MCP joint, the extensor tendon splits into three slips. The middle slip, which connects to the proximal phalanx by sagittal bands, inserts on the base of the middle phalanx. The two lateral slips unite more distally on the base of the distal phalanx after receiving contributions from the interossei on both sides and the lumbrical on the radial side (Fig. 15.1B). On the radial side of each digit, the lumbrical unites with the lateral slip to form the lateral band. The interossei also insert into the lateral slips to form the lateral bands in addition to the base of the proximal phalanx and joint capsule.

The flexor tendons on the volar side of the finger include the flexor digitorum superficialis (FDS) and the flexor
digitorum profundus (FDP). The FDS tendon travels volar to the FDP and splits to form two slips that attach to the base of the middle phalanx and function to flex the PIP joint. The FDP tendon is located dorsal to the FDS and inserts into the base of the distal phalanx and flexes the DIP joint.

The anatomy of the wrist comprises one of the most complex joints in the body. The eight wrist carpal bones articulate with the radius and ulna and allow for a large arc of motion in three degrees of freedom. The proximal row of carpal bones includes the scaphoid, lunate, triquetrum, and pisiform, which are closely approximated to the distal radius. The triangular fibrocartilage complex, an articular disk located between the proximal row of carpals and the ulna, completes the concave surface on which the carpals move. The distal row of carpal bones includes the hamate, capitate, trapezium, and trapezoid, which articulate with the metacarpals. The scaphoid is the common link between the proximal and the distal row of carpals.

Injuries to the hand and wrist are common in athletes of all levels. The two main types of injuries suffered by athletes include soft-tissue injury (tendon and ligament) or bony injury (fracture and/or dislocation). Thumb injuries should be considered a discrete group of injuries compared with the other digits as the anatomy and function differ significantly.

The hand is usually out in front of the athlete and used to catch a ball in motion, brace any falls, and block opponents. The middle finger is a commonly injured finger because it extends most distally, allowing it to be vulnerable to jamming, catching, and torsion. Thumb injuries are more common in falls to the side or reaching behind to brace a fall, such as during skiing. The small finger can also easily be injured as it gets caught on a jersey. An axial load to a closed fist or a misdirected punch may cause a metacarpal fracture or CMC injury. Any fall on an outstretched hand can cause a hyperextension injury and lead to fracture or ligamentous injury in the wrist.

Injuries to flexor and extensor tendons can occur during athletics, but injuries to the extensor mechanism are more common because they are weaker when compared to the flexors. The common injuries of the extensor mechanism include the mallet finger, acute boutonniere, and sagittal band injuries. The main injury to the flexor tendon suffered during sporting events is an FDP avulsion injury, also known as jersey finger. Whereas most of the extensor injuries seen are easily treated with splinting and observation, all flexor tendon injuries should be referred to a hand surgeon urgently for surgical fixation.

Extensor tendon injuries such as mallet finger and acute boutonniere injuries are common injuries in ball sports such as basketball, when the athlete’s fully extended finger is struck by the ball. In a mallet finger, the result is a stretching or disruption of the terminal tendon, which is responsible for active extension of the DIP joint. An acute
boutonniere injury ranges from a sprain to complete disruption of the central slip that can result from a volar PIP dislocation. An avulsion fracture is possible with both of these injuries, so x-rays need to be done to evaluate for this variant of injury.

Injury to the sagittal bands can result in pain and extensor tendon subluxation during finger flexion. These injuries may occur from blunt trauma, forced flexion of the MCP joint, or sometimes even minor insults. These injuries usually involve a sagittal hood tear of the radial side of the long finger.

An FDP avulsion/rupture results from a forceful hyperextension of the DIP joint while the FDP is contracting. A classic example is catching the middle finger on a competitor’s jersey. The tendon may rupture from its insertion or avulse a small bone fragment from the distal phalanx. The tendon may retract into the finger or palm.

Fractures of the metacarpals and phalanges are the most common fractures of the upper extremity.³ The thumb and small finger are the most frequently fractured.⁴ The majority of these fractures can be managed nonoperatively, but unstable fractures need to be recognized and referred to a hand surgeon for operative management. Regardless of treatment, the goal is to restore hand function and prevent stiffness or deformity.

The most commonly dislocated joint in the body is the PIP joint of the finger. Injury to the PIP joint can range from a jammed finger to a complex irreducible fracture dislocation. The severity of these injuries is often underestimated, and improper treatment may cause long-term disability. The direction of dislocation is usually dorsal, but volar and lateral dislocations may occur.

The DIP and MCP joints are less commonly dislocated. Dorsal dislocations are the more common variant of these IP dislocations. DIP dislocations are usually related to a crushing-type injury and are more prone to open injuries because of the tissue attachments distally. It is important to realize that MCP joint dislocations can be either simple subluxation injuries that can easily be reduced or a complex complete dislocation that usually requires surgery to relocate.

All IP dislocations are associated with some ligamentous injury. The most common soft-tissue injury with joint dislocations is avulsion of the volar plate. Collateral ligament and tendon avulsions are also possible at the time of injury. Intra-articular fractures can occur and range from small, insignificant avulsions to larger triangular or comminuted fractures that make up a significant portion of the joint.

Injuries to the thumb MCP joint are quite common. The most common injury to the MCP joint is an ulnar collateral ligament (UCL) disruption. This injury occurs when an athlete falls on an outstretched hand with the thumb abducted, as might occur when a skier falls while holding a pole.

The wrist is a complex anatomic structure made up of eight carpal bones, the distal radius, distal ulna, and multiple tendons and ligaments. It is beyond the scope of this chapter to discuss every injury that can occur to the intricate wrist, but the more common athletic injuries should be recognized. Appropriate treatment of wrist injuries can prevent future disability. Scaphoid fractures are by far the most common carpal fracture. Other acute sporting injuries to the wrist include hamate fractures and scapholunate ligament tears.