In this retrospective study, surgeons look back over the medical records and treatment results of 127 patients with an acute (recent) thoracolumbar burst fracture. Treatment for this condition isn’t cut and dry. There are still many questions about the best way to go: should the patient have surgery to stabilize the spine? Or can the problem be treated just as well with a nonoperative (conservative) approach?
The purpose of the study was to see how well patients did in the long run with conservative care. At the same time, the authors looked to see if the Load Sharing Classification, a method used to direct what type of surgery should be done, can also be used to predict if surgery is even necessary. If the score on the Load Sharing test does not indicate surgery and conservative care is the approach taken, what would the predicted long-term results be for nonsurgical treatment based on the total Load Sharing score?
Thoracolumbar burst fractures occur in the spine where the end of the 12 thoracic vertebrae meet the start of the five lumbar vertebrae. A high-energy load through the spine causes the vertebra to break or shatter into many tiny pieces. The danger of these fractures is that the bone fragments can shift and press into the spinal cord or spinal nerve roots causing temporary and even permanent neurologic damage. Burst fractures are most often caused by car accidents or by falls.
These types of fractures are grouped or classified using the Load Sharing Classification system already mentioned. There are three major groupings or ways to classify the fracture. The first is severity based on the amount of comminution (size and number of fractured pieces of bone). There are three levels of comminution or involvement: the number one represents little means there was less than 30 per cent of the bone affected. Between 30 and 60 per cent of bone involvement is labeled two or referred to as more. And more than 60 per cent of the vertebral body fractured is a subgroup labeled three and called gross.
The second Load Sharing Classification grouping is by apposition of fragments. This is a rating of how much the bone fragments have displaced (moved apart or separated). Minimal displacement is given a grade of one. Spread at least two millimeters apart but with less than half the vertebral body affected is a rating of two. And a wide displacement with more than half the body affected and spreading more than 2 millimeters qualifies as a three subgroup.
And finally, the Load Sharing Classification includes deformity correction. This is a measure of the severity of vertebral collapse and loss of vertebral body height. The severity of (spinal) canal compromise and the degree of neurologic deficit tell the surgeon whether the injury is stable or unstable.
Studies in the past have directed surgeons to use a posterior approach (incision from the back of the spine) when there is a mild comminution and an anterior approach (incision along the front of the body) when fractures are severely comminuted. This study evaluates the effectiveness of the classification scheme by looking at long-term results.
Patients included in the study were between 18 and 60 years old and had a burst fracture of any vertebrae between T11 and L2. All were treated with a nonoperative (conservative) approach. Anyone with burst fractures from osteoporosis, cancer, or other diseases causing a spontaneous fracture was excluded. Only medical records of patients with thoracolumbar burst fractures caused by high-energy compression from trauma were reviewed. Most of these were from falls or car accidents.
Scoring for Load Sharing Classification was done using X-rays and CT scans. Treatment included spinal positioning with pillows, soft rolls, or traction. The goal was to reduce the spine and realign it as much as possible. Vertebral fractures of this type often affect the front of the vertebral body. Collapse of this portion of the spine results in a kyphotic deformity. Kyphosis means the spine curves forward. If the treatment is not successful in maintaining spinal alignment during and after healing, the patient can become bent over as a result. This effect is referred to as loss of kyphosis correction.
Patients were kept on bedrest until the pain was tolerable. Anyone with neurologic impairment was given steroid therapy while in the hospital. Once the pain was reduced, they could walk and move about with a brace or body cast. The brace or cast was worn for at least three months.
Patients could return-to-work after the cast or brace was removed (approved by the surgeon). X-rays were taken when patients were admitted to the hospital with this injury and repeated for comparison at the end of three months, six months, one year, and at the final follow-up visit. Everyone was followed for at least three years. Some patients were seen for up to 12 years.
Various angle measurements were measured each time (e.g., vertebral wedge angle, lower intervertebral angle, and loss of kyphosis correction). Pain level, neurologic recovery, and work status were also recorded.
The recovery rate for patients was very high (93 per cent). The Load Sharing score taken from X-rays and CT scans right after the injury occurred did correlate with the angle of kyphosis (correction maintenance or loss) at the end of the study. Patients with good correction of the kyphosis deformity had less severe pain and better overall function (including return to work).
The results of this large study indicate that conservative care for thoracolumbar burst fractures is both safe and effective — even when there are neurologic signs of a severe injury. Judging from the scores on the Load Sharing Classification test and the final outcomes, it looks like this test can be used — not just for deciding what type of surgery to do, but also determining if surgery is even needed. Scores as high as a nine in patients with unstable fracture were treated successfully with conservative therapy.
A small number of patients treated nonoperatively eventually had to have surgery. Their back pain and poor functional outcomes required surgical intervention to stabilize the spine. Patients who opt for conservative care after traumatic thoracolumbar burst fractures can expect acceptable long-term results. Surgeons can use the Load Sharing Classification score to help guide patients in making the appropriate treatment decision regarding surgery versus conservative care.