The Therapeutic Effects Of PLIF Versus PLF With Pedicle Screw Systems For The Treatment Of Adult Isthmic Spondylolisthesis

OBJECTIVE:To compare the efficacy and radiological outcomes of PLIF and PLF with pedicle screw systems in the treatment of adult isthmic spondylolisthesis, and the association between these factors and the clinical outcome was explored by the means of Binary Logistic Regression.METHODS:A retrospective study was performed to analyze the clinical data of patients who were treated with PLIF or PLF due to isthmic lumbar spondylolisthesis in the First Affiliated Hospital of Soochow University from July2005to January2011.The final follow-up was taken by the telephone revisit, the questionnaire survey form inquiry and the outpatient service reexamination revisit. A total of94patients were followed-up and available for complete clinical and radiograph, the patients were devided in two groups according to different fusion methods. Group PLIF:posterior lumbar interbody fusion (55patients), Group PLF:posterolateral lumbar fusion (39patients).Disc space height(DH), Degree of spondylolisthesis(DS), Segmental lordosis(SL), Lumbar lordosis(LL) and sacral slope(SS) were compared both before and after the operation and during the final follow-up. The respective operation duration, amount of bleeding, complications, fusion rate of the two group patients were recorded. The JOA score and VAS(low back pain and leg pain) were used to evaluate the clinical outcome.Univariate analysis and Logistic regression analysis were taken to analyze if age, gender, fusion method, preoperative DH, preoperative DS, preoperative JOA score, preoperative low back and leg pain VAS, postoperative DS and DH improvement may affect the clinical outcomes.RESULTS:The follow-up period ranged from12to77months with an average of36.3months. The average operation duration and amount of bleeding had obvious advantage in the PLF group(P<0.05), yet PLIF group turned up better results in all the post operation radiological measurements, which was statistically significant. The fusion rate was94.5%and87.2%respectively, which was not statistically significant. The rate of complications had no statistically difference. The VAS for both lumbar and leg pain as well as the JOA score were significantly improved in the final follow-up time, the rate of the improved JOA score(RIS) was68.7%in PLIF group and66.0%in PLF (P>0.05).Univariate analysis showed that age, gender, fusion method preoperative DH, preoperative DS, preoperative low back pain VAS, lose rate of DS were not significant effect to clinical outcomes (P>0.05). Postoperative DS reduction rate, postoperative DH, follow-up DH, preoperative leg pain VAS and preoperative JOA score had significant effect to the clinical outcomes(P<0.05). And these factors were classified into Binary logistic regression analysis model. Preoperative leg pain VAS and preoperative JOA score were the statistically significant factors to the clinical results(P<0.05)CONCLUSION:1. Both PLIF and PLF give a good satisfactory results for the treatment of adult isthmic lumbar spondylolisthesis.2. The operation duration and amount of bleeding were more in PLIF group, yet PLIF has superiority over PLF in correction of spondylolisthesis, maintenance of DH, regaining of segimental and lumbar lordosis. And PLIF contributes to a higher fusion rate.3. Logistic regression analysis showed that Preoperative leg pain VAS and preoperative JOA score were the statistically significant factors to the clinical results.