Complex Injuries of the Hand





CRITICAL POINTS





  • Complex hand injuries involve multiple tissue systems.



  • A complete history and understanding of the injury circumstance as well as a prompt and thorough examination of the patient is critical.



  • Treatments are typically multifaceted.



  • Rehabilitation plays a critical role in optimizing outcomes.



Complex injuries to the hand are defined as injuries involving more than one group of tissues. The tissue systems involved may include bone, joint, tendon, ligament, vessel, nerve, and skin. A delicate balance of anatomy and physiology exists within the hand. Complex hand trauma includes a wide spectrum of injury and can lead to significant morbidity and functional loss. Early diagnosis and thorough evaluation will help to ensure prompt and optimal treatment.


The integrated tissue systems each serve a purpose in allowing the hand to be used. Bones provide structural support. Joints allow for motion of the hand and wrist, and the ligaments help to maintain stability of the joints. Tendons arise from muscle bellies and insert into bone and facilitate motion of the bones and joints. Nerves are the electrical plug-in for the muscles and give sensory feedback to the brain. Skin provides an elastic protection of the deeper tissues from the outside world. Blood vessels ensure the viability and nutritional status of these aforementioned structures.


Complex injuries to the hand can involve a multitude of mechanisms such as industrial accidents, high-pressure injections, high-energy trauma, burns, traumatic amputations, and crush injuries, just to name a few. The severity of trauma can often be obvious, such as a complete or nearly complete amputation. However, other injuries, such as high-pressure grease-gun injections, can be deceptively benign at initial presentation. Multiple surgeries (both primarily and secondarily) are not uncommon, and therapy is a critical component in helping to ensure an optimal outcome. The timeline for recovery is likely prolonged. In addition, all stages of recovery are fraught with potential pitfalls. As many of these injuries are contaminated and have skin loss, infection is a major concern. Stiffness, deformity, chronic pain, paresthesias, and functional loss can routinely result.


Hand injuries are generally very common and represent nearly 30% of all trauma seen in the emergency department. Based on a classification system proposed by Campbell and Kay, a recent study further examining the epidemiology of these injuries found that approximately 40% of hand traumas presenting to the emergency department are moderate to severe in nature. Most injuries occurred in the domestic setting and affected young or middle-aged men. Trybus and colleagues found that use of industrial machinery was associated with more severe injuries. In addition, the average total treatment time was nearly 3 months, and more than 60% of patients had some degree of permanent disability. This underscores the importance of thorough examination, appropriate treatment, and team approach including the therapist, patient, and surgeon.




History and Physical Examination


Combined hand injuries can be isolated to the affected extremity or may occur as part of multiple injuries. A systematic approach to evaluation of these patients will help to ensure that all components of the patient’s trauma are diagnosed and overlooking any aspects of their injury is avoided. In cases of high-energy accidents, the physician must be sure that there is no visceral or life-threatening head trauma. The patient’s airway, breathing, and circulation need to be assessed and maintained. Profuse or uncontrolled bleeding from the extremity can be controlled in the acute setting by holding pressure on the wound or applying a tourniquet proximally.


Understanding the limits that come with patients who may be unresponsive, uncooperative, or sedated, a complete history and review of systems is essential in evaluating persons with extremity injuries. Hand dominance and employment of the patient should be included in the history. A good understanding of the patient’s home life and age will also be helpful in deciding the best treatment. The mechanism of injury is important in predicting or raising suspicion of trauma to specific tissue groups.


Understanding co-morbidities is helpful in predicting outcome and determining the best treatment options. These factors are important for preparing realistic treatment plans and avoiding medical- and extremity-related complications. For instance, persons with a significant cardiovascular history, pulmonary disease, or diabetes will be at greater risk with longer anesthesia times. Success of microvascular reconstruction or replantation will be decreased in patients with peripheral vascular disease, diabetes, or inflammatory arthritis. Immunosuppressed patients will often experience delayed healing and increased risk of infection.


The medication history of the patient can affect treatment. For instance, the use of anticoagulants can affect hemostasis. The social history will also shed important information regarding their medical history and aid in decision making regarding treatment. Tobacco use is notoriously associated with diminished healing and success of revascularization. Heavy use of alcohol or illicit drugs is important information that will help the treating team better understand the patient. One of the major challenges of the health care provider lies in understanding the commitment of the patient to his or her recovery. More complex reconstructions often require closer follow-up and detailed rehabilitation to maximize their success. It is critical that the patient understand the importance of compliance and follow-up after the initial treatment. The optimal treatment for complex injuries may need to be tailored to fit within these limitations. With clear communication, the patient and health care provider can formulate the ideal initial treatment, establish follow-up care needs, and lay the groundwork for realistic outcome expectations.


The circumstances and details of the patient’s injury can provide important information regarding complex hand injuries. For instance, the mechanism of traumatic amputation is important in predicting the success of reattachment. Avulsion injuries ( Fig. 94-1 ) have a large zone of injury and are notoriously more difficult to reconstruct compared with sharp amputations. Some injuries will be more subtle. For instance, a crush injury may not show obvious deformity or skin defect, but may lead to marked swelling and compartment syndrome ( Fig. 94-2 ). High-pressure injections are also injuries that lead to significant morbidity and long-term functional loss. Multiple surgeries are common, and the recovery is often prolonged. However, they often present as benign injuries with a small puncture wound and their severity may be overlooked, which can compromise their overall outcome.




Figure 94-1


A, B, A 54-year old male who got his thumb and index finger caught in a conveyor. The amputated thumb and finger (A) and the hand (B) are shown. The zone of injury for this mechanism of injury is notoriously long and attempted replantation was unsuccessful. He went on to have a groin flap for wound coverage.



Figure 94-2


A, Patient with a crush injury to the hand. B, Posteroanterior radiograph demonstrating fractures of the index, middle, and ring finger metacarpal bases. C, Compartment pressure measurements help to confirm clinical suspicion of compartment syndrome. D, E, Appropriate fasciotomy incisions are marked out on the dorsal (D) and palmar (E) sides of the hand.


The setting in which the injury took place, the time elapsed before treatment is initiated, and the scheduling of specific interventions and surgical procedures are all important factors to consider. Some locations such as barnyard or farm settings are notoriously dirty, and wounds can be expected to be contaminated and will require urgent and aggressive debridement to minimize the risk of infection. Contaminated wounds more than 8 to 12 hours old may likely be left open and undergo serial debridement before contemplating formal closure to minimize risk of infection. Definitive treatment of associated injures can be delayed until the wound is clean. Chemical injuries may occur in certain industrial settings, and it is important to understand special treatments. For instance, hydrofluoric acid contamination should be treated with copious irrigation followed by neutralization with calcium gluconate solution and/or infusion. Duration from the time of injury also carries special significance in limbs with compromised vascularity. Amputated fingers, hands, and arms require prompt treatment and revascularization. Warm and cold ischemia times need to be considered. Traditional teaching suggests that these patients should be treated within 6 hours of injury. Finger replantations can usually be attempted within this time range. However, more proximal injuries (e.g., forearm level) have a greater risk of failure because more muscle is at risk of ischemic damage ( Fig. 94-3 ).




Figure 94-3


A 4-year-old boy was in a motor vehicle accident and sustained a nearly complete amputation of the forearm. His warm ischemia time was approximately 8 hours. Despite successful reattachment, muscle necrosis and infection developed that necessitated amputation.


Physical examination of patients with hand injuries should be performed in a systematic fashion to ensure that nothing is overlooked. However, the entire patient must also be assessed. Appropriate Advanced Trauma Life Support protocols should be used when applicable. A complete evaluation of the skin, bone, tendon, nerves, and perfusion of the extremity should be performed. Some aspects of the physical examination may be limited by patient pain, unresponsiveness, or lack of cooperation. Additional injuries may be discovered when they are sedated or in the operating room. Although it does not preclude surgical intervention, in unconscious patients, complete examination information (such as a sensory examination) will be delayed until the patient is responsive and cooperative.




Ancillary Studies


Plain radiographs in at least two planes are an essential part of the evaluation of complex hand injuries. In addition to assessing the bones for fracture, these studies will reveal the joint alignment and overall structural integrity of the extremity. Radiographs may also demonstrate the presence of radiopaque foreign bodies or free air within the soft tissues. When clinically indicated, special views will help identify certain types of fractures. For instance, a radiograph of the wrist in an extended and ulnarly deviated position can help to better show the scaphoid bone in the coronal plane. Oblique views can help to show injuries of the metacarpal bones or carpal bones such as the hamate. Traction radiographs can also provide the surgeon with additional information regarding the fracture patterns.


Many complex injuries will require immediate surgical attention for treatment of open or contaminated injuries. Time permitting, more specialized studies can be helpful in providing the caregiver with additional information. CT scans will show the bony anatomy in more detail and help confirm the presence of subtle fractures. MRI can help better evaluate the bone marrow, soft tissues, and presence of foreign material.


Treatment


Much of the decision regarding the course of treatment will be outlined by the surgeon and patient (when possible) in the preliminary evaluation. Before proceeding with treatment, it is important for the caregiver to educate and outline the plan. Factors such as the injury pattern, experience and expertise of the treating team, and patient’s needs and preferences will contribute to formulation of the appropriate treatment plan.


Early treatment decisions for some of these injuries can help to minimize the number of repeat surgeries and optimize the long-term outcome. For instance, the use of amputated or discarded parts for skin coverage or reconstruction of the bones, tendon, vasculature, or nerves of the hand can be helpful. It is also important for the patient to have a realistic understanding of the details of rehabilitation and outcome. Although cosmetically pleasing, many digits after replantation may be stiff and painful and ultimately provide no functional improvement compared with an amputated digit.


Complex injuries often have complex wounds that require appropriate irrigation and debridement. This step is critical in helping to prevent infection and lays the foundation for good healing. Typically, irrigation is performed with normal saline solution or sterile water. Although traditionally there has been a tendency by many to use antibiotics in sterile saline solution, recent investigations have found no added benefit with the use of antibiotics for bacterial contamination. A detergent can be added in cases of chemical or industrial (e.g., grease, paint) infiltration. Aggressive sharp debridement of nonviable tissues is essential. Severely contaminated wounds will often benefit from serial debridements. Obtaining cultures at the time of initial debridement will help to identify infectious organisms and guide appropriate antibiotic treatment.




Musculoskeletal Injuries


Bones and joints make up the support structure for the hand and upper extremity. Fractures and dislocations can disrupt their function if they fail to heal or become malaligned. This can result in stiffness, pain, and diminished use of the hand. Fractures can have several characteristics. For instance, open fractures involve a violation in the skin, resulting in exposure of the bone. These fractures add a level of complexity to the patient’s injury. They are associated with higher energy trauma and have a greater amount of soft tissue damage. As a result, there is an increased incidence of infection, avascular necrosis, and diminished healing ( Fig. 94-4 ). Intra-articular fractures extend into the joint and may result in joint incongruity and significant cartilage damage. These injuries carry a higher risk of the development of joint stiffness, pain, and post-traumatic arthritis. Trauma involving disruption of the joint ligaments can result in instability and incongruity.




Figure 94-4


Carpal osteomyelitis and septic arthritis developed in a patient 6 weeks after open reduction for lunate dislocation. Follow-up anteroposterior radiograph demonstrated carpal osteopenia, erosions, and sclerotic appearance of lunate, suggestive of osteonecrosis.


The optimal treatment of complex fractures is based on multiple factors. Ultimately, surgical fixation will usually be the best treatment for unstable fractures. Rehabilitation and early range of motion will not likely be feasible until reconstruction of the skeleton is achieved. However, this must be balanced with the viability and cleanliness of the wound and soft tissue coverage. For instance, wounds with significant contamination and skin defects will increase the risk of exposed hardware to infection. Multiple surgical treatment options can be used including plates and screws, K-wires, intramedullary pins, tension band wiring, and/or external fixation. Plates and screws tend to provide very rigid fixation and typically will allow for early range of motion. However, use of this technique requires more extensive surgical dissection, which may result in devascularization, periosteal stripping, and slower wound healing. This may also increase the risk of infection. Alternatively, K-wires can be inserted percutaneously, obviating the need for extensive dissection. Unfortunately, the strength of fixation is typically less than that of open reduction and internal fixation. External fixation can be used either alone or in conjunction with pinning and enhances the rigidity of the construct ( Fig. 94-5 ). External fixation also allows access to the soft tissues while helping keep the bones aligned and their length maintained. External fixation may also be used as a temporary means of maintaining fracture reduction. For instance, if appropriate wound coverage and decontamination of the wound is achieved, more permanent or rigid hardware may then be used, thereby allowing early aggressive range of motion. Unfortunately, K-wires and external fixation carry a higher risk of pin-tract infection. Intramedullary fixation can be inserted with minimal soft tissue dissection and can also maintain bone length and alignment. However, intramedullary fixation has limited potential for rotational control. Studies evaluating outcomes of open fractures associated with complex injuries have shown that metacarpal injuries generally fared better than phalangeal fractures. Fractures of the proximal phalanges or proximal interphalangeal joint with associated tendon injury carried a poor prognosis.


Apr 21, 2019 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Complex Injuries of the Hand
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