Author
Lars Grimm, MD, MHS
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.
Editor
James Neal Long, MD
Assistant Professor of Plastic and Reconstructive Surgery
Division of Plastic Surgery
University of Alabama at Birmingham and Kirklin Clinics
Birmingham, Alabama
Disclosure: James Neal Long, MD, has disclosed no relevant financial relationships.
Injuries to the hand and wrist are very common, especially among young active adults. Humans rely on their hands for the vast majority of their work and leisure activities. Delays in the diagnosis or treatment of hand injuries can lead to significant morbidity as many long-term complications are dependent on timely intervention. Although some injuries can be treated by nonspecialists, it is important to understand the diagnostic and therapeutic options so that patients can be triaged appropriately. The radiograph shown demonstrates a dislocation of the thumb metacarpophalangeal (MCP) joint. Image courtesy of David Schwartz, MD.
Upper extremity vascular injuries are increasingly common, with a high degree of morbidity. The brachial artery, followed by the axillary, radial, and ulnar arteries, are most commonly injured. Penetrating trauma is the most common cause, usually secondary to a gunshot, stab wound, or laceration. Physical examination findings can be divided into hard and soft signs. Hard signs include pulsatile bleeding, expanding hematoma, thrill, bruit or evidence of ischemia such as pallor, paresthesias, paralysis, pain, pulselessness, and poikilothermia (shown). Soft signs include moderate hemorrhage, stable hematoma, fracture, peripheral nerve deficit, and proximity to penetrating wound.
Palpable radial pulses do not exclude a vascular injury because the rich collateral network may lead to normal physical examination findings. Objective evaluation may be performed with the Allen test, in which there is compression and sequential release of the ulnar and radial artery to evaluate perfusion of the palmar arch. The gold standard imaging modality for vascular injury is conventional arteriography (shown), which can identify the precise location of injury. Noninvasive imaging modalities include duplex ultrasonography and CT angiography.
Treatment for peripheral vascular injuries is either surgical or endovascular. Temporary vascular control can be achieved with digital pressure or a blood pressure cuff. Primary repair is performed with end-to-end anastomosis of native vessels if possible or with synthetic or autologous graft if the vessel is badly damaged. Endovascular treatment can be used to embolize bleeding from noncritical arteries or from low-flow arteriovenous fistulas. Reperfusion and increased fascial compartment pressures place patients at risk for compartment syndrome. If compartment syndrome develops, then fasciotomy is needed to help relieve pressure (shown).
High-pressure injection injuries are a workplace hazard for industrial workers. Injection pressures of 2000-10,000 psi easily penetrate human tissue. The injected material causes a direct toxic effect as well as tamponade-induced necrosis. Substances such as paint thinners can dissolve lipids, leading to tissue necrosis at low pressure. The most common injection site is the tip of the nondominant index finger, as shown in this case of a high-pressure paint injection. Treatment involves empiric broad spectrum antibiotics, debridement of necrotic tissue, wound irrigation, and open packing. Unfortunately, many cases require partial amputation due to the large area of necrosis.
Injuries to the fingertip include crush injury, nail root avulsion, lacerations, burns, or frostbite. Usually the history can provide sufficient information to guide therapy. Although simple lacerations can be sutured closed, those that involve the nail should have the nailplate removed to allow for suture repair of the nailbed (shown). The nailplate can then be reattached. Subungual hematomas should be treated with either removal of the nail or drainage through the nail via an electrocautery device.
Extensor tendon lacerations of the hand and fingers are most commonly the result of direct laceration, crush injury, avulsion, burns, bites, or deep abrasions. There is usually a concomitant skin injury. The extensor tendons are very shallow, placing them at increased risk for injury. The classic presentation is a digit that stays flexed despite efforts at extension. Injury to the terminal insertion of the extensor or the distal interphalangeal joint will produce a mallet finger deformity, and injury to the central slip or to the proximal interphalangeal joint will produce a boutonniere deformity (shown). Up to 80% of the tendon may be lacerated without significant loss of function.
Repair of an extensor tendon laceration requires a careful understanding of the anatomy and the exact location of the laceration. The goals of therapy are definitive wound debridement, early tendon repair, and early range-of-motion therapy. Repair is via surgical closure (shown) with one of several techniques. Straightforward cases may be repaired in the emergency department but should otherwise be treated by an experienced hand surgeon. The most common long-term complications are joint stiffness and tendon adhesions. The longer the period of immobilization, the greater the chance of a fibrotic reaction that limits motion.
Injuries to the flexor tendon are often the result of minor puncture wounds or lacerations and, if open, can be associated with neurovascular deficits. The natural resting position of the hand will provide important clues about the location and extent of injury. Partial lacerations may present with preserved function but pain with flexion. Complete lacerations will disallow flexion. Both the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) should be tested independently and in tandem. To assess the FDP tendon, the MCP and PIP joints are stabilized, and the patient flexes the distal phalanx. To test the FDS tendon, the distal phalanx is held extended, and the patient flexes the finger.
Before treatment of a flexor tendon injury, a thorough neurovascular examination should be performed as open injuries are often associated with neurovascular deficits. All flexor tendon injuries should be repaired in the operating room, ideally within 24 hours. Identifying the proximal end of the tendon can be difficult in complete dissociations because the tendon will retract into the palm. Care must be taken to preserve the flexor tendon sheaths (labeled) because the biomechanics of the flexor tendons require an intact tendon and pulley system, otherwise the tendon will bowstring.
Paronychia is the most common type of hand infection characterized by erythema, tenderness, and swelling of the nail fold. Staphylococcus aureus is most commonly cultured in acute paronychia usually after a minor traumatic event, even as simple as a hangnail (shown) or nail biting. Chronic paronychia is usually secondary to Candida albicans in patients whose hands are constantly moist, like dishwashers, or those who are immunocompromised or with vascular insufficiency. In early stages, antibiotics may prevent the development of an abscess. If an abscess does develop, the eponychial fold can be elevated, the abscess irrigated, and the area packed with gauze. In advanced cases, the infection may track under the skin of the finger to produce a felon.
Phalangeal fractures and dislocations are common injuries in all age groups. Injuries in young patients are more likely to be sports related, while in older patients falls are more common. The clinical presentation is dependent on the mechanism of injury. Crush injuries to the fingertip usually involve the nail bed and the distal phalanx. Injuries to the interphalangeal joints present with swelling, ecchymosis, and decreased range of motion. Fractures through the phalanx may angulate the finger depending on the location in relation to the intrinsic muscles of the handle. The radiograph shown demonstrates a proximal interphalangeal (PIP) fracture-dislocation.
After initial bedside evaluation, the workup for phalangeal fractures begins with plain radiographs in multiple orthogonal plains. There is little role for CT or MRI. Closed reduction is the treatment of choice for reducible and stable phalangeal fractures, which represent the majority of phalangeal fractures. Distal phalangeal fractures (DP) require stack splints, which immobilize the DP through the distal interphalangeal (DIP) joint only. Middle phalangeal and PIP joints can be splinted with volar resting or ulnar phalangeal gutter splints, with the MCP joint in 70 degrees of flexion and the PIP and DIP joints in extension. After 3 weeks of splinting, motion exercises can be initiated using customized splints, such as the figure-of-eight splint shown, and after 4-6 weeks the splint can be removed based on clinical exam.
Surgical intervention is reserved for complicated phalangeal fractures. Indications for operative treatment include open, irreducible, unstable, or displaced intra-articular fractures, as well as failed closed reductions. Percutaneous pins (shown), minicondylar plates, or inter/intraosseous wiring may be used depending on the location and extent of fracture involvement. Most fractures are treated with internal fixation, with external fixation used temporarily to maintain the soft tissue envelope and preserve skeletal length in fractures with bone loss or contamination. Potential complications include malunion (most common), loss of motion, nonunion, and infection.
Metacarpal fractures and dislocations are very common, accounting for 40% of all hand fractures. Carpometacarpal (CMC) injuries are usually due to a fall with the wrist flexed, metacarpal injuries are usually due to axial loading or direct trauma, and MCP dislocations are usually the result of forced hyperextension of the proximal phalanx on the MCP. Although there are classic examination findings for each individual metacarpal fracture, in general the most important things to evaluate are external lacerations, abrasions, and contusions; joint deformity and positioning; pain; swelling; and loss of motion. The image shown demonstrates dislocation of the second MCP; note the position of the finger and dimpling of the skin (arrow).
Plain radiographs are the first-line imaging modality to evaluate metacarpal fractures. Most dislocations can be evaluated with physical examination only. Images must be obtained in multiple planes and hand positions to ensure no subtle fractures are missed. Commonly obtained views include posterior-anterior, lateral, oblique, Roberts (best for first metacarpal base), Brewerton (best for metacarpal heads), and clenched fist. CT is reserved for detailed evaluation of intra-articular injuries. The oblique radiograph shown demonstrates fourth and fifth metacarpal fractures.
Most metacarpal fractures and dislocations can be treated nonoperatively with closed reduction. After reduction, a splint is applied over the forearm to maintain alignment and is followed by early range of motion. Reduction should be performed in an environment where percutaneous pinning may be used if the reduction is deemed unstable. For more complicated fractures or those that fail closed reduction, internal fixation can be achieved via intramedullary pins, K-wires, or AO plates. A radiograph of the same patient in the prior slide is shown with intramedullary pin fixation. The primary long-term complication is early arthritis, which can be reduced by anatomic reduction and avoiding prolonged immobilization.
Thumb fractures and dislocations can lead to a high level of disability. Injuries are most frequently the result of motor vehicle and bicycle accidents. Dislocations to the interphalangeal joint usually occur in the dorsal direction secondary to hyperextension. Fractures to the metacarpal base are commonly due to axial loading applied to a slightly flexed metacarpal shaft, and several specific fracture patterns have been described. Bennett fractures are intra-articular basilar fractures in which a single volar ulnar base fragment is produced (arrow shown).
The clinical presentation of a thumb fracture or dislocation depends on the location. Pain, swelling, and decreased range of motion are usually secondary to soft tissue injury. Crepitus may be present with displaced intra-articular fractures. Plain radiographs are usually sufficient to confirm the diagnosis. While many fractures can be treated with closed reduction, those that are unstable or intra-articular usually require open fixation usually with pinning or plates. The radiograph shown demonstrates a Bennett fracture that has been pinned, though open reduction and internal fixation are often required.
Author
Lars Grimm, MD, MHS
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.
Editor
James Neal Long, MD
Assistant Professor of Plastic and Reconstructive Surgery
Division of Plastic Surgery
University of Alabama at Birmingham and Kirklin Clinics
Birmingham, Alabama
Disclosure: James Neal Long, MD, has disclosed no relevant financial relationships.
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