Distal Ulna Fracture
What is It, How is it Managed, and More
Author: Ali Syed, PharmD
Illustrator: Jillian Dunbar
Copyeditor: David Walker
What is a distal ulna fracture?
A distal ulna fracture, or isolated ulnar shaft fracture, is a type of fracture that occurs along the length of the ulna bone, which is one of the two bones in the forearm. A distal ulna fracture may occur at different sections of the ulna bone, such as near the wrist at the farthest (distal) end of the bone, the middle of the ulna bone, or near the elbow at the top (proximal) end of the ulna bone.The ulna is located on the pinky-finger side of the forearm, next to the radius, which is the other bone in the forearm located on the thumb side. Fractures of the forearm can occur as a single fracture involving either the radius or ulna or as a combined fracture involving both the radius and ulna. A distal ulna fracture, when isolated, is typically a result of direct trauma, while indirect trauma commonly results in a concomitant radial fracture to the forearm. Direct trauma to the forearm may be a result of direct impact of an object to the forearm, such as from a ball when playing sports, a strike from a blunt object, or from a car accident. Indirect trauma to the forearm may be a result of falling from a height and landing on an outstretched arm.
How common is a distal ulna fracture?
Distal ulna fractures rarely occur in isolation and are commonly found to occur in conjunction with distal radius fractures. Radius and/or ulna fractures account for approximately 44% of all forearm fracture related visits to the emergency department in the United States. The majority of distal ulna fractures occur in youth involved in sports who may sustain direct and indirect forearm injuries as well as in older adults with osteoporosis.
What are the signs and symptoms of a distal ulna fracture?
Symptoms of a distal ulna fracture most commonly include generalized pain and/or swelling of the forearm, worsening pain with hand or forearm movement, as well as loss of forearm and hand function due to a limited range of motion. Signs of a distal ulna fracture include gross deformity of the forearm, open fractures, and tense forearm compartments. Deformities of the forearm may be characterized by the wrist hanging at an odd angle or protrusion of bone. Open fractures, consisting of an open wound in the skin near the site of the fracture, may also occur if the broken bone penetrates the skin. Tense forearm compartments are commonly characterized by abnormal pulse and pressure readings in the forearm.
How is a distal ulna fracture diagnosed?
A distal ulna fracture is typically diagnosed by a medical professional after physical examination and imaging of the forearm. A physical examination of the forearm in an individual with a distal ulna fracture may reveal deformity of the forearm, discoloured skin, open wounds, and tense forearm compartments. A neurovascular examination of the forearm may be conducted by assessing the radial and ulnar pulses as well as sensory and motor function of the median, radial, and ulnar nerves. A neurovascular exam is used to assess the radial and ulnar arteries and to rule out any deficits in nerve function that may have been a result of the fracture.
Radiographic imaging of the forearm, most commonly with the use of an X-ray and sometimes a CT scan, may be performed in order to visualize the forearm, rule out additional existing injuries, and confirm diagnosis of the distal ulna fracture. Standard radiographs may include anterior-posterior, lateral and oblique views of the forearm.
How is a distal ulna fracture treated?
Depending on the severity of the distal ulna fracture, treatment may involve conservative or surgical interventions. In some cases, conservative measures can be used to completely treat the fracture. This is most common amongst children with distal ulna fractures and sometimes amongst adults with stable, isolated ulnar shaft fractures. Conservative treatment involves the application of a cast or functional brace to the affected forearm for approximately 4-6 weeks while avoiding any weight bearing. During this time, a medical professional will closely follow progress with the use of X-rays and physical exams to ensure healing. After cast removal, physical therapy, routine physical examinations, and gradual weight bearing may occur in order to restore a full range of motion in the affected forearm.
In most adults with a distal ulna fracture as well as in individuals with complex or open fractures, a surgical approach may be required. The type of approach is dependent on the affected bones and complexity of the fracture but can include an open reduction internal fixation in which a medical professional makes an incision in the forearm to reach the fractured bone and moves it back to its original position. External fixation is another surgical approach, which involves the external application of plates and screws into the forearm bone(s) to achieve stability of the fracture. Intramedullary nailing is another surgical technique involving the insertion of a metal rod across a fractured bone in order to provide support. Surgical treatment of open fractures commonly involves urgent bone realignment, wound irrigation, and the use of antibiotics to prevent infection.
After surgery, the forearm is commonly put into a splint or cast for comfort and protection, and individuals will need to avoid weight bearing for six weeks. Range of motion exercises are encouraged after one week of the initial fracture treatment under the supervision of a medical professional alongside close monitoring of the healing process through images and physical exams.
How long does it take a distal ulna fracture to heal?
In most individuals, complete healing of a distal ulna fracture takes approximately two to three months after initial treatment. However, distal ulna fractures may heal at different rates depending on the complexity of the fracture and specific factors, such as an individual's past medical history and compliance with the prescribed treatment plan.
What are the most important facts to know about a distal ulna fracture?
A distal ulna fracture is a type of fracture that occurs along the length of the ulna bone, which is one of the two bones in the forearm. They occur most commonly in youth and elderly populations and are characterized by symptoms of pain, swelling, and limited range of motion and specific signs, such as deformity, open wound, and/or tense forearm compartments. Distal ulna fractures are commonly diagnosed using a combination of imaging and physical exams. Treatment options may include different types of surgery and/or application of a cast, depending on the nature of the fracture. Distal ulna fractures typically take two to three months to heal after initial treatment and often require close follow up with a medical professional to ensure appropriate healing.
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Resources for research and reference
Johns Hopkins Medicine (2021). Ulna and Radius Fractures (Forearm Fractures). Johns Hopkins Medicine. Retrieved June 13th 2021 from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/ulna-and-radius-fractures-forearm-fractures
Richards, T. A., & Deal, D. N. (2014). Distal ulna fractures. The Journal of Hand Surgery, 39(2), 385-391.
Sharareh, B and Riehl, J (2021). Isolated Ulnar Shaft Fracture. OrthoBullets. Retrieved June 12 2021 from: https://www.orthobullets.com/trauma/422969/isolated-ulnar-shaft-fractureSmall, R. F., & Yaish, A. M. (2021). Radius and ulnar shaft fractures. Statpearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK557681/