The posterior lumbar interbody fusion (PLIF) with cages in the treatment of segmental spinal instabilities.

Purpose: The technique of posterior lumbar interbody fusion (PLIF) has been critically discussed due to a high degree of complications, including the development of pseudarthrosis. With the recent establishment of intercorporeal implants new aspects have to be contemplated in surgieal techniques, especially concerning the posterior approach. In this study we present our first results after intercorporeal stabilisation of segmental spinal instabilities utilising carbon and titanium cages. Method: 45 spinal instabilities were surgically stabilised in 42 patients who were evaluated on average for 2.8 years post-operatively. 12 patients had isthmic and 19 patients degenerative instabilities while 11 patients suffered from instabilities resulting from prior spinal surgery. Results: Assessed according to the Hambly-score, 69% of the patients had an exzellent or good result; 2 (4.8%) patients were subjectively worse off than before surgical treatment. After implantation of cages precise radiological evaluation of bony ingrowth is frequently impaired by artefacts. We found that three months after implantation of a titanium cage, which had to be removed after incorrect placement, no bony consolidation was visible. Persisting or recurrent instabilities in fused segments were not recorded. Conclusion: By means of PLIF and implantation of cages the interbody space is reconstructed and jeopardised neural structures are decompressed. In addition to this, the frequently osteochondrotically degenerated segment is immobilised. The posterior approach allows decompression of neural structures and, with comparable results concerning stability, the considerable risks of the ventral approach are avoided.