[Treatment of thoracolumbar spinal fractures using internal fixators (evaluation of 120 cases)].

PURPOSE OF THE STUDY: A group of 120 patients was evaluated with acute injury of Th-L spine who were operated on from posterior approach with the use of Dick AO fixator or USS fixator in the period of 1991-1996.

MATERIAL: In the period of 1991-1996, 128 patients were operated on with the acute injury of Th-L spine. Evaluated were 120 patients: 81 men (67.5%) of average age 40.1 years (age range, 16-74 years) and 39 women (32.5%) of average age 35.4 years (age range, 15-66 years). Posterior stabilization using the internal fixator was combined with posterolateral or posterior interarticular fusion. In comminuted fractures of the vertebral body transpedicular cancellous bone grafting was performed and starting for 1995 also intercorporal transpedicular fusion.

METHODS: The evaluation covered location and type of fractures, injury of other levels of the spine, other associated injuries, neurological symptomatology prior to the surgery and 3 months after the surgery, duration of surgery and of image intensifier exposure, peroperative and early postoperative complications, radiograph evaluation of the degree of reduction, the loss of correction after 12 months and after the hardware removal.

RESULTS: Evaluated were 120 patients. Average interval after the surgery at the time of the evaluation was 43.7 months (range, 24-93 months). The injury was caused in 82 cases (68.3%) by a fall from height, in 26 cases (21.7%) by a car accident and in 12 cases (10%) by another cause. Associated injuries included: calcaneus fracture 18 times, the fracture of ankle 4 times, pelvis fracture 4 times, other fractures 18 times. In 89 cases the injury involved only one vertebra, i.e. one level, 31 cases were multi-level injuries. The angle of the kyphosis of vertebral body was on average 21.8 degrees. Patients with neurological symptoms were on average operated on 2-12 hours after the admission, other patients were operated on in the interval between 5 hours and 7 days. Bilateral transpedicular cancellous bone grafting was performed in 106 affected vertebrae, the canal was revised in 27 injured vertebrae. The surgery took on average 172 minutes (range, 62-430 minutes). Image intensifier exposure lasted on average 2.4 minutes. Average blood loss was peroperatively estimated at 725 ml, postoperatively on average at 815 ml. Postoperative complications: healing of the wound per secundam 6 times, thromboembolic complication in 9 cases--never fatal, pneumonia 3 times, uroinfection 5 times. The total number of these complications was about 8%. Vertebral body was completely restored in 72 cases, incompletely in 34 cases (up to 5 degrees deficit). The correction of kyphosis achieved was on average 6.5 degrees. After 12 months the correction loss with the fixator in place was on average 2.5 degrees. After the removal of the fixator the average correction loss was 5.5 degrees. In 2 cases there occurred a significant re-dislocation which required revision surgery. Transpedicular screws broke 6 times in the total of 4 patients, fixator loosened in 2 cases.

DISCUSSION: Surgical treatment of thoracolumbar spine is indicated in unstable injuries and all injuries with neurological lesion and a proved compression of spinal canal. Decompression of the spinal canal is often achieved by reduction, lordotization and distraction. In other cases revision of the canal is indicated. Stabilization is performed by means of a transpedicular internal fixator. Part of the surgery is posterior fusion. The defect in the reduced body is treated by transpedicular cancellous bone grafting. The affected inervertebral disc must be treated by intersomatic fusion. Anterior operation is indicated as a complementary one.

CONCLUSIONS: 1. Absolute majority of injuries of thoracolumbar spine may be treated from the posterior approach. In this it is necessary to restore the stability of the anterior column. An indispensable part of the operation is a flawless posterior fusion. 2. Some types of injuries require a complementary anterior approach in the first or second step. This applies mainly to the injuries with a defect of anterior column evaluated on the basis of classification after Gaines. 3. A primary isolated anterior approach to the treatment of the injury of Th-L spine is not in our view suitable as a routine.