Spinal fusion is the act of growing two vertebrae into one, thus eliminating the intervertebral joint. Spinal fusions are still sometimes necessary, despite the work of Prof. Dr. Bertagnoli and others in non-fusion techniques. Some of the conditions that can lead to spinal fusion are:
- Spinal Tumor
- Vertebral Fracture
Degenerative conditions that would normally lead to artificial disc replacement may also require spinal fusion, if the degeneration of the vertebrae has progressed too far. If multiple disc levels are involved a hybrid construct is also possible, where a spinal fusion may be applied in the center level or the end closest to a fixed joint like the sacra. The artificial disc replacements would be placed as to isolate the fusion from other disc joints.
There are two main types of spinal fusions, the posterior-lateral fusion, which bridges the facet joints posteriorly (behind) to the spinal cord, and the interbody fusion, which requires the removal the disc, residing between the vertebral bodies, to insert the bone grafts anteriorly (forward) to the spinal cord. A combination of these procedures is known as a 360 fusion.
Within the classification of the interbody fusion for the lumbar spine there are two types the (A)nterior (L)umbar (I)nterbody (F)usion ALIF and the (P)osterior (L)umbar (I)nterbody (F)usion PLIF. These terms apply the anterior/ventral or posterior/dorsal approach to the disc space. In special situations an alternative surgical technique to the ALIF is the (A)nterio(L)ateral trans(P)soatic (A)pproach ALPA. This procedure is done through the psoas muscle to insert fusion cages using. This alternate anterior lumbar interbody fusion (ALIF), also known as the ALIF – S technique, is used in only specific cases. Most fusions have instrumentation, such as plates, rods, screws and cages, anchored to the bone to facilitate the fusion of the bone. This is known as fixation. This instrumentation is intended to remain.
The fusion of the bones, one to another, may take an average -3-6 months, upwards to a year, depending on the health and life-style of the patient. If fusion does not complete in this time, more surgery is likely. Moreover, the doctor may require that an orthesis be worn by the patient to further immobilize the affected area.