Objective: To evaluate the surgical procedure of endoscopic transforminal discectomy, bone grafting and Dynalok pedicle screw fixation under X-Tube operation system in the treatment of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis.
Methods: From June 2004 to May 2006, 42 patients with classic features of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis underwent endoscopic transforminal lumbar interbody fusion (TLIF). Under the guidance of fluoroscopy, a 2.8 to 3.0 cm incision with 4.5 to 5.0 cm apart from the posterior middle line was made on the symptomatic side and the working portal (X-Tube) was docked unilaterally on the facet joint. A total facetectomy was then performed to expose neural foramina and nerve root. Discectomy and endplate preparation were completed through the tube. A Telamon cage was placed obliquely into the intervertebral space after interbody grafting, and then the Dynalok pedicle screw fixation system was performed. This procedure was accomplished on the lateral side when it is necessary.
Results: Clinical outcomes were determined using the Oswestry Disability Index (ODI) which revealed that 62.2% of patients got excellent results, 29.2% good and 8.6% fair. The average hospital stay was 12.5 days (5-25 days). Operation time averaged 240 min (110-320 min), blood loss averaged 140 ml (80-420 ml) and incision length averaged 3 cm (2.8-3.2 cm). Five patients had complications including wound infection in 1 case, incision dehiscence and focal skin necrosis in 1, progressive radicular pain of contralateral leg in 1 and residual radicular numbness after transient radicular pain in 2.
Conclusions: This surgical procedure of endoscopic transforminal diskectomy, bone grafting, cage placement and pedicle screw fixation can be effectively accomplished under X-Tube operation system with predominant benefits such as small incision, less stripping of paraspinal muscles, minimal blood loss and rapid postoperative recovery.