Clay Shoveler’s Fracture Causes and Treatment

Clay Shoveler’s Fracture Causes and Treatment

Fractures in the cervical spine can occur with acute or repetitive trauma. Clay shovelers fracture is an avulsion fracture of the spinous process. It occurs with abrupt flexion of the head such as found with motor vehicle accidents, diving, or wrestling injuries. It also occurs with repeated stress caused by the pulling of the trapezius and rhomboid muscles on the cervical and thoracic spinous processes. Repetitive and forceful muscle contraction breaks the spinous process and pulls the avulsion segment away from the original spinous process. Clay shovelers fracture most commonly occurs in the lower cervical and upper thoracic spinous processes, namely C6, C7, and T1. The spinous avulsion and fractures are also caused by direct blows or trauma to the base of the neck. This is usually a very stable fracture and does not produce any neurologic deficits.  Patient’s are alarmed when they hear the term fracture or break in the neck, but this part of the bone is not near the spinal cord or nerve roots. Clay shovelers fracture derives its name from a common occurrence in clay miners in Australia during the 1930s. The men were digging deep ditches and tossing clay 10-15 feet above their heads with long handled shovels. Instead of having the clay come cleanly off the shovel, it would sometimes stick. The sticking clay produces a sudden contraction of trapezius and rhomboid muscles in response to a sudden surge of shear forces from the weighted shovel. The muscles respond quickly and forcefully, contracting to stabilize the spine and shoulders. The Australian clay shoveler’s would hear a pop and feel a sudden sharp pain between the shoulder blades. As expected, the clay shovelers were unable to continue working after suffering the injury because every time the trapezius or rhomboid muscles would contract, they would feel sharp stabbing pain in the spine. The mechanism of injury is believed to be the result of sudden and forceful muscle contraction transmitting force through the supraspinatus ligaments. The tremendous force is concentrated across the spinous processes and produces an avulsion fracture on the longer spinous processes of the lower cervical and upper thoracic spine.

Plain Film X-rays and Examination

On the lateral (side view) x-rays, an oblique radiolucent fracture line can be seen through the base of the spinous process. It is more likely to be in the back or distal tip of the lower cervical and upper thoracic spinous process. Rough margins or serrated edges are commonly seen with the acute fractures, which differentiates it from nonunion of the secondary growth center of the spinous process. In addition, nuchal bones would also not be displaced or have the serrated margins. The distal portion of the fractured spinous process is often displaced downward (caudally or inferior). This is due to the trapezius and rhomboid pull on the avulsion segment of bone.   Frontal x-rays (anterior to posterior) may show the appearance of two spinous processes at a single vertebrae, which is called the “double spinous process sign.” This visual sign is useful for determining a clay shoveler’s fracture, especially when the cervicothoracic junction is poorly visualized on the lateral view. An MRI (magnetic resonance imaging) or CT (computed tomography) is not usually required. A bone density scan may be indicated in a person who has experienced prior avulsion, thoracic, or lumbar spinal compression fractures. If bone density is in question, a bone density scan can evaluate and measure cervical and lumbar spine t-scores; which gauges relative risk of future spinal compression fractures.

Symptoms of Clay Shoveler’s Fracture

Clay shoveler’s fracture can occur with any repetitive and forceful activity utilizing the trapezius and rhomboid muscles. It could occur with motor vehicle accidents for traumatic blows to the side and top of the spinous process. In most cases, pain is associated immediately after the injury and is described as a burning or “knife-like” stabbing pain.  Other symptoms include muscle tightness and sharp pain that increases with repeated activity, similar to severe muscle strain in the upper back joints or muscle strains. The broken cervical spine is very tender, as are the nearby muscles.

Treatment of Cervical Spine Avulsion Fractures

Most cases resolve within a few weeks. Chronic pain or long-term irritation to the area could be associated with the muscle and tendon junctions that insert on the original spinous process or avulsion segment. Many patients do not require treatment besides rest or NSAIDS (non steroidal anti-inflammatory medication). Others may benefit from muscle relaxers or pain medication prescribed by your primary care or physician. Analgesic medicines can be applied directly to the muscles in the neck and upper back to relieve soreness and possible rhomboid muscle strains. Adjacent bones and thoracic ribs should not be affected or produce back pain. Some patients require physical therapy or massage therapy to help decrease muscle pain and spasms. Ice, heat, electrical, ultrasound, light stretching, and range of motion exercises may help relieve neck and upper back pain. Some patients respond to class IV cold laser treatments (low level laser therapy) to help decrease pain and inflammation in the muscles and tendons. Others may benefit from more aggressive muscle therapies such as Active Release Technique or Graston Technique to break up fascial adhesions or scar tissue associated with years of repetitive activities. Patients can expect some discomfort for several weeks during the healing process. With the hands above the head or in front of the body, the trapezius and rhomboid muscles are contracting, which continues to aggravate the vertebrae and cause spinal pain. Symptoms are worse with the head down and arms in front of the body, such as driving or working at the computer. With time and some treatment, symptoms will decrease with day to day activities.  Physical exercise and strenuous activity may need to be avoided for 1-2 months post injury. For patient’s with a history of multiple stress fractures or avulsion fractures, a bone density scan may be indicated. More information and examples of plain film radiographs can be found here  X-ray for Clay Shoveler’s Fracture. For more information on contacting a Sioux City Orthopedic Surgeon for serious injuries that require a specialist evaluation.  Some types of fractures can be unstable and require immediate attention.  Other fractures should be evaluated to make sure they are stable and then monitored by an orthopedic surgeon.