1 Introduction topenlarge
B2 injuries indicate a bony and/or ligamentary failure of the posterior tension band together with a Type A fracture of the vertebral body. Type A fracture should be classified separately as management depends on both.
In cases where neurological deficit is observed and compression of the spinal canal is assumed, decompression has to be performed. It should be understood that this is a step that can also result in deterioration of neurology unless very meticulously performed.
Decompression can be performed anteriorly or posteriorly. Posteriorly, decompression can be indirect or direct. Indirect decompression may be tried before performing direct decompression. Please refer to Decompression techniques for a detailed discussion of indications for the posterior decompression techniques. ( Posterior decompression)
2 Closed reduction topenlarge
Primary reduction is performed by positioning of the patient onto a frame to create lordosis.
3 Reduction with pedicle screws topenlarge
Due to the fact that bilateral instrumentation is necessary in all cases, all steps described below are repeated on the opposite side, unless stated otherwise.
Pedicle screw insertion
In patients with B2 injury with A3/A4 fractures of the vertebral body at the thoracic level, posterior long segment fixation is performed to provide better reduction forces. Fixation of multiple spinal segments does not affect functionality in the thoracic spine due to the presence of rigid rib cage.
In this technique, pedicle screws are inserted two levels above and below the fractured level on both sides.
This is essential in rotationally unstable injuries where stress on the posterior implants is high. ( Pedicle screw insertion)
The contouring of the rod depends on the site of the fracture. A rod contoured in mild kyphosis is chosen for fractures from T1-T10. A straight or a slightly lordotic rod is chosen for fractures from T11-L1, and a rod contoured to lordosis is chosen for lumbar fractures.
The rod is inserted sequentially, either from distal to proximal or the other way round. The distal screw heads are tightened.
The rod is then inserted into the proximal screw heads without tightening.
Proper rod contouring helps in achieving appropriate sagittal alignment.
If it is decided to perform an indirect decompression, this is done at this stage. If indirect decompression proves to be insufficient, a direct decompreesion eg, posterior or transpedicular decompression are undertaken. Refer to the Posterior Decompression techniques for detailed instructions. ( Posterior decompression)
With the help of a distractor, the proximal screws are distracted along the rod. This is done on both sides simultaneously.
Pitfall: Avoid overdistraction
Care should be taken to avoid overdistraction in type B2 fractures.
The screw heads are tightened with the inner nuts to secure the reduction achieved.
Cross links are applied at the top and bottom of the construct to provide biomechanical stability. In type A injuries one cross link might be sufficient.
The final construct is shown from a lateral view
4 Fusion top
Although fusion was routinely performed for all spinal fractures, its indications are now being restricted to fractures that are highly unstable.
Nonfusion fixations can be performed for A3, A4, and B1 type injuries.
Fusion is routinely performed for A2, B2, B3, and all C injuries as they are unstable injuries with extensive soft tissue and ligamentous disruption.
If the surgeon plans for a fusion, the facet capsule is excised and the joint cartilage surfaces are denuded/curetted.
Pieces of bone graft (autograft, allograft) are inserted into the decorticated facet joint for fusion.