Clinical Analysis of 102 Patients with Spondylolisthesis

Jung Keun Suh, MD
Se Hoon Kim, MD (Seoul)

Objective:

This retrospective analysis was conducted to determine the efficacy of posterior lumbar interbody fusion combined with transpedicular screw fixation in a group of patients treated for isthmic and degenerative spondylolisthesis.

Methods:

102 patients with isthmic and degenerative spondylolisthesis were treated with decompressive surgery and posterior lumbar interbody fusion combined with transpedicular screw fixation from Jan. 1993 through Dec. 1998. There were 74 females and 28 males with a mean age of 52.8 years, ranging 21–74. The authors stabilized the spine with interbody fusion cages in 84 cases, and transpedicular screw fixation was performed in 98 cases. There were 56 isthmic (55%) and 46 degenerative (45%) types. In isthmic types, slippages were between L3–L4 in 3 cases, between L4–L5 in 21 cases and L5–SI in 32 cases. In degenerative types, slippages were between L3–L4 in 7 cases, between L4–L5 in 36 cases and L5–51 in 3 cases. The degree of anterior displacement averaged 15.0% preoperatively and 6.8% postoperatively in isthmic, 14.1% preoperatively and 5.9% postoperatively in degenerative types. With an average 13 months follow–up, 99 patients (97.1 %) exhibited radiologic fusion. Complications included 3 instrument failures, 1 spinal epidural hematoma. Clinical results were excellent in 68 (66.7%), good in 18 (17.6%), and fair in 16 cases (15.7%), as evaluated using McNab's criteria.

Conclusion:

Laminectomy with posterior interbody fusion and transpedicular screw fixation is a recommended procedure for the treatment of isthmic and degenerative spondylolisthesis, and it can achieve a satisfactory radiologic and clinical outcome.