[Unilateral pedicle screw fixation versus its combination with contralateral translaminar facet screw fixation for the treatment of single segmental lower lumbar vertebra diseases].

OBJECTIVE: To compare the advantages and disadvantages of unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion in treating single segmental lower lumbar vertebra diseases.

METHODS: Sixty-two patients with single segmental lower lumbar vertebra disease who received treatment between January 2008 and June 2009. These patients were consisted of 16 males and 46 females, ranging in age from 27 to 72 years old, with a mean age of 51.6 years old. Among these patients, lumbar degenerative disease had in 22 patients, recurrence of lumbar intervertebral disc protrusion in 13 patients, lumbar intervertebral disc protrusion accompany with spinal canal stenosis in 12 patients, massive lumbar intervertebral disc protrusion in 5 patients and lumbar degenerative spondylolisthesis with degree I in 10 patients. The lesions occurred at L3,4 segment in 5 patients, at L4,5 segment in 42 patients, and at L5S1 segment in 15 patients. Thirty patients underwent unilateral pedicle screw fixation (unilateral screw fixation group, group A) and thirty-two patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation (bilateral screw fixation group, group B). Lumbar interbody fusion with intervertebral cages was also performed in all patients. Incision length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Loosening or breakage of internal fixations, displacement of intervertebral cages and interbody fusion conditions were observed in each group. Preoperative and postoperative intervertebral height, coronal and sagittal Cobb angle and wound pain at 72 h after operation were compared between two groups. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the cinical effects.

RESULTS: Neither wound infection, skin necrosis, nerve root or cauda equia injury, nor worsened neurological dysfunction in the lower limb occurred in each group. There were no significant differences in incision length, intraoperative blood loss and postoperative wound drainage between two groups. The operation time in group A was significantly shorter than that of group B (P < 0.05). There were no significant differences in visual analogue scale value of the wound pain at postoperative 72 h between two groups (P > 0.05). All patients were followed up for 12-48 months,with a mean of 27.5 months. The intervertebral height of all patients had obviously recovered at 5 days after operation, furthermore, at the final follow-up, it still had well maintained. During follow-up, no pedicle screw and/or translaminar facet screw loosening, displacement or breakage and displacement of intervertebral cages were found. The lumbar interbody fusion rate was 96.7% and 96.9% in group A and group B, respectively, and there was no significant difference between two groups (P > 0.05). JOA score of all patients got obviously improved after operation (P < 0.05) and there was no significant difference between two groups (P > 0.05).

CONCLUSION: Both unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion have advantages of small incision, minimal invasion, simple operation, reliable stability, high interbody fusion rate,rapid recovery, encouraging clinical effects and less complications. Compared with unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation, the operation of unilateral pedicle screw fixation is simpler and can avoid using special equipments. Therefore, unilateral pedicle screw fixation plus lumbar interbody fusion can be used in treating single-segmental lower lumbar vertebra diseases under the precondition of strictly grasping indications for surgery and improving surgical skills.