[ALIF and PLIF interposition in low-grade isthmic spondylolisthesis L5/S1 : Longterm-Comparison of interbody fusion techniques (ALIF - PLIF)].

INTRODUCTION: For the treatment of isthmic spondylolisthesis two alternative interbody fusion techniques are available, the dorsoventral interposition in ALIF technique and the dorsal access interposition in PLIF technique. Due to the complications of anterior lumbar surgery and in order to avoid a second operation, the dorsoventral fusion technique is becoming uncommon and mainly a pure dorsal supply is performed. The aim of the study was to compare the clinical long-term results of both treatment techniques.

MATERIALS AND METHODS: 138 patients were treated surgically between 2003 and 2012 in symptomatic isthmic spondylolysis in L5/S1 with a Meyerding degree of I-III. 72 patients were evaluated finally (ALIF n = 25 and PLIF n = 47). The average follow-up period was 7.9 years for the ALIF group and 5.6 years for the PLIF group. In both groups the average drug consumption, duration of recovery, resumption of work and resumption of sport activities was recorded.

RESULTS: The results showed an extended time of surgery and a prolonged hospitalization of 5.4 days for the ALIF group. The ODI had a greater improvement in the PLIF group but this difference was not significant. The VAS was reduced in both groups. 36.8 % of the ALIF group and 44.7 % of the PLIF group reported a reduced pain medication postoperatively. The average recovery was 16 weeks for both groups. 29 % of PLIF and 9 % of ALIF patients had no pain relief. ALIF patients were able to get back to work after 149 days and the PLIF patients after 178 days. 31 % of the PLIF group and 13 % of the ALIF group were not able to return back to work. Revisions of fusion and the rate of wound revisions were increased in the PLIF group, adjacent segment diseases occurred more frequently in the ALIF group.

CONCLUSION: Both treatment and fusion techniques (ALIF/PLIF) were able to achieve a significant pain relief and reduced consumption of pain medication postoperatively. The recovery period was similar in both groups, but there were differences regarding the date of return to work, hospitalization, duration of surgery and ODI score. Neither of the two methods could show a definite advantage.