Mechanism of Injury
The Colles fracture, the most common fracture of the wrist, was first described by Abraham Colles in 1814. In this injury, there is a complete fracture of the distal radius (typically the last two centimeters) usually accompanied by damage to the ulnar collateral ligament or the ulnar styloid process. Middle aged women and elderly are more commonly reported with this type of fracture.
Colles fracture typically occurs when a person falls and uses a pronated hand and outstretched arm to try to break the fall. In this position the wrist is usually at 40-90° in dorsiflexion. The pressure from the fall over-extends the hand and breaks the radius just above the wrist. When this occurs, the distal part of the bone tends to become dorsally displaced. It is also frequently comminuted, meaning it is broken into multiple pieces.
In most people, the radial styloid process is longer, and therefore projects farther, than the ulnar styloid process. In a Colles fracture, the radius may be shortened, reversing this relationship. The ulnar styloid process may be avulsed, or broken off, as well which results from the force through an intact triangular fibrocartilage complex. A distal radial fracture with palmar displacement can also occur.
Gosta Frykman identified many different forms of Colles fracture and classified it into eight different types based on the extra- or intra-articular nature of fractures involving the distal ends of the radius and ulna.
Clinical Presentation & Assessment
The clinical presentation of Colles fracture is frequently described as a dinner fork deformity - distal fracture of the radius causes posterior displacement of the distal fragment, causing the forearm to be angled posteriorly just proximal to the wrist. With the hand displaying its normal forward arch, the patient’s forearm and hand resemble the curvature of a dinner fork.
Neurovascular assessment is performed on the affected hand by taking radial and ulnar pulses. Gentle check on the ability of fingers to perform abduction and adduction, and movements on each interphalangeal joints is also done.
Diagnosis & Management
A plain radiograph is usually required to confirm the diagnosis. Reduction is done usually for a displaced fracture under general anesthesia or interscalene brachial block. A splint or cast is required to hold the forearm in a stable and in immobilised position. In case of displaced intra-articular fractures with palmar dislocation, open reduction and internal fixation are sometimes required. Physiotherapy is advised after fracture healing for better strengthening of muscles and range of movements.
Patients frequently heal well with no complications at all. If redisplacement of the Colles fracture is seen a few cases week after reduction, it's important to take and check radiographs a week-10 days after injury. Possible complications include:
- persistent translation of the carpus
- shortening of radius
- stiffness of the wrist and the forearm
Few very rare complications are carpal tunnel syndrome, Sudeck's atrophy and ulnar and radial compression neuropathy
Special Concerns in Children & Elderly
Due to the abundant circulation in that region, the fractured parts of the radius tend to refuse well. If this fracture occurs in children, however, the fracture line may extend through the distal epiphyseal plate, potentially leading to misalignment of the plate with the radius. If this occurs, growth of the radius may be affected.
In patients above 50 years of age, osteoporosis screening is recommended for a better outcome. Osteoporosis is one of the biggest risk factors in wrist fractures and patients suffering from osteoporosis tend to have greater deformity after Colles fracture.
An 83 year-old female trips in her apartment. As she falls, she throws out her arm straight out, palm to the floor, to try to catch herself. An hour later, her daughter arrives for a visit and finds her mother on the floor, conscious and oriented, but unable to stand. They rush to the hospital, where doctors find that the elderly mother has broken her radius and her hip.
In older adults, Colles and other fractures can be sequelae of osteoporosis, an acquired condition caused by thinning of the bony trabeculae. This leads to reduced bone mass and increased fragility of the bone, increasing its susceptibility to fractures.
Osteoporosis can be primary or secondary. Primary osteoporosis is the most common form, and is associated with aging (senile osteoporosis) and the postmenopausal state in women due to the decrease in estrogen levels following menopause. Secondary osteoporosis can result from endocrine disorders (hyperparathyroidism, diabetes, multiple myeloma, etc.), gastrointestinal disorders (malnutrition, malabsorption syndromes, vitamin D deficiency, etc.), drugs (anticoagulants, chemotherapeutic agents, corticosteroids, and others), and more.
Because it is asymptomatic until a fracture occurs, osteoporosis can be difficult to diagnose. Additionally, serum levels of calcium, phosphorus, and alkaline phosphatase (ALP) tend to be normal in these patients.
By supplementing the diet with calcium and vitamin D and adopting regular exercise habits prior to age 30, the risk of osteoporosis later in life can be reduced. Treatments to prevent further bone resorption include bisphosphonates, calcitonin, estrogen, and the monoclonal antibody denosumab; and bone formation can be stimulated with parathyroid hormone or an analog.