COMPLICATIONS OF FRACTURE
A major objective in the management of fractures and dislocations is to avoid as many complications as possible. The principles of fracture treatment direct the surgeon to reduce the fracture and immobilize it with a cast/splint or internal/external fixation devices, to allow natural healing to occur. A variety of complications, either as a consequence of the injury itself or as a consequence of treatment, can produce serious and permanent problems. Acute complications such as damage to nerves and blood vessels, adult respiratory distress syndrome, and infection usually arise from the injury itself. Complications also develop during the healing process and may lead to irreparable loss of function. Chronic complications include failure of union, deformities, osteoarthritis, joint stiffness, implant failure, and reflex sympathetic dystrophy.
Displacement of fracture fragments or bone ends at a dislocated joint often produces compression or laceration of adjacent vessels and nerves. Critical neurovascular structures (e.g., the brachial plexus) lie deep in the limb, close to the skeleton, which protects them from injuries. A fracture or dislocation makes nerves or vessels vulnerable to injury from sharp bone fragments or from entrapment in the fracture site.
Neurovascular complications must be identified by careful examination immediately after the injury and after any manipulation of the injured limb. Some complications are not immediately evident but do appear 24 to 48 hours after injury. Reexamination and monitoring are essential both during this period and while circumferential compression dressings and casts are in place. Prompt and sometimes aggressive treatment is required to restore function and prevent permanent loss.
Radial Nerve Palsy
The radial nerve is commonly damaged in fractures of the shaft of the humerus (see Plates 2-19 and 2-32). Normally protected in the spiral groove on the humeral shaft, the nerve is easily impaled by a fracture fragment or entrapped in the fracture site. Aggressive manipulation of the fracture during closed reduction may also result in nerve entrapment. Wristdrop is a common long-term consequence of this injury.
Neurovascular Injury to Elbow
A musculoskeletal injury that is frequently associated with neurovascular injury is the supracondylar fracture of the humerus in children. In the most common extension-type fracture, the humeral shaft fragment is displaced anteriorly, impinging on the critical neurovascular structures in front of the elbow. The median, radial, and ulnar nerves are all susceptible to direct injury from the displaced fracture fragment (median nerve most commonly injured), and the brachial artery may be lacerated or entrapped in the fracture site at the time of injury or during closed reduction. Distal neurovascular function must be assessed critically, and manipulative reduction must be very careful and gentle.
Effective immobilization of a fracture or dislocation in a cast or splint, if prolonged, can lead to joint stiffness, which may prove to be a bigger problem than the injury itself. Immobilization lasting more than a few weeks leads to scarring of the joint capsule and contracture of the muscles, and it also impairs the nutrition of the articular surfaces. With prolonged immobilization, adhesions develop across the articular surfaces, even in joints that had not been injured directly. In addition, prolonged immobilization results in marked atrophy of the muscles in and around the site of injury. Rehabilitation to regain motion can be a long and difficult process that may not restore full function.
Most treatment protocols, either nonoperative or operative, typically recommend beginning range of motion early in the recovery period to avoid the development of stiffness. Nonoperatively, this can be accom- plished with use of functional braces that adequately immobilize the injury for healing but still allow range of motion. For example, traditional cast immobilization for a fracture of the humeral shaft requires immobilization of the shoulder and elbow joints in a shoulder spica cast. Such immobilization of both joints for 8 to 10 weeks would lead to a significant loss of function. Conversely, a functional brace allows active range of motion in the shoulder and elbow joints yet provides adequate support of the healing fracture. A functional brace is applied 10 to 14 days after injury, once the initial swelling has subsided. The brace is adjustable and can be tightened to provide firm support about the arm and maintain acceptable alignment of the fracture. Inability to maintain stable reduction of a fracture or dislocation early in the postinjury period through non-operative measures is an indication for open reduction and internal fixation. Surgical stabilization will then allow range-of-motion exercises without fear of loss of reduction.
When joint stiffness develops, restoring motion often requires a long-term rehabilitation program. After the patient regains joint motion with gentle passive range-of-motion exercises, active exercises are begun to strengthen the atrophied muscles. When fixed contractures fail to respond to aggressive and prolonged rehabilitation, surgical release of soft tissue may be necessary as a last resort. At the elbow joint, this includes release or excision of the contracted and thickened joint capsule.