Single segment of posterior lumbar interbody fusion for adult isthmic spondylolisthesis: reduction or fusion in situ

Abstract

Objective: We prospectively compared surgical reduction or fusion in situ with posterior lumbar interbody fusion (PLIF) for adult isthmic spondylolisthesis in terms of surgical invasiveness, clinical and radiographical outcomes, and complications.

Methods: From January 2006 to June 2008, 88 adult patients with isthmic spondylolisthesis who underwent surgical treatment in our unit were randomized to reduced group (group 1, n = 45) and in situ group (group 2, n = 43), and followed up for average 32.5 months (range 24-54 months). The clinical and radiographical outcomes were compared between the two groups.

Results: The average operative time and blood loss during surgery showed insignificant difference (p > 0.05) between two groups. The radiological outcomes were significantly better in group 1, but there was no significant difference between two groups of clinical outcomes, depicting as VAS, ODI, JOA and patients' satisfaction surveys. Incident rate of surgical complications was similar in two groups, but in group 1 the complication seemed more severe because of two patients with neurological symptoms.

Conclusions: For the adult isthmic spondylolisthesis without degenerative disease in adjacent level, single segment of PLIF with pedicle screw fixation is an effective and safe surgical procedure regardless of whether additional reduction had been conducted or not. Better radiological outcome does not mean better clinical outcome.

Fig. 1

a After insertion of pedicle screws, the rods were contoured and provisionally secured to the caudal screws, leaving a gap between the cephalad pedicle screws and rods that reflected the spondylolisthesis. b, c Drawing back the cephalad pedicle screws with reduction system and tightening the nuts over the rods and down onto the screw shanks, the cephalad screws were drawn back onto the rods, achieving the correction of the olisthesis. d Distracting the pedicle screws to increase the interbody disk height and clear out the disk space contents. e PEEK cages were inserted to the disk space for interbody fusion and the pedicle screws were compressed to restore the lumbar lordosis

Fig. 2

Surgical procedure performed intraoperatively in a 51-year-old woman with grade II isthmic spondylolisthesis at L4–5. a Preoperative lateral X-ray showed grade II slippage and interbody space collapse. b Pedicle screws were inserted at L4–5, the rods were contoured and provisionally secured to the L5 screws, leaving a gap to draw back L4. c With reduction system, L4 was drawn back and reduction completed. d PLIF was performed and focal lordosis was restored

Fig. 3

Surgical reduction and PLIF performed in a 52-year-old woman with grade III isthmic spondylolisthesis. Preoperative lateral X-ray showed that slippage was 51.4 % and focal lordosis was 6.4° (a). Postoperative X-ray showed that complete reduction of the spondylolisthesis was obtained and focal lordosis increased to 25.9° (b)

Fig. 4

A 53-year-old woman with grade II isthmic spondylolisthesis was surgically treated with PLIF in situ. Preoperative lateral X-ray showed that slippage was 34.1 % and focal lordosis was −3.0° (a). Postoperative X-ray showed that disk space distracted with olisthesis partially reduced to 19.3 % and focal lordosis increased to 8° (b)