Superior outcomes of decompression with an interlaminar dynamic device versus decompression alone in patients with lumbar spinal stenosis and back pain: a cross registry study.

INTRODUCTION Surgical decompression for lumbar spinal stenosis (LSS) has been associated with poorer outcomes in patients with pronounced low back pain (LBP) as compared to patients with predominant leg pain. This cross registry study assessed potential benefits of the interlaminar coflex® device as an add-on to bony decompression alone. METHODS Patients with lumbar decompression plus coflex® (SWISSspine registry) were compared with decompressed controls (Spine Tango registry). Inclusion criteria were LSS and a preoperative back pain level of ≥5 points. 1:1 propensity score-based matching was performed. Outcome measures were back and leg pain relief, COMI score improvement, patient satisfaction, complication, and revision rates. RESULTS 50 matched pairs without residual significant differences but age were created. At the 7-9 months follow-up interval the coflex® group had higher back (p=0.014) and leg pain relief (p<0.001) and COMI score improvement (p=0.029) than the decompression group. Patient satisfaction was 90% in both groups. No revision was documented in the coflex® and one in the decompression group (2.0%). DISCUSSION In the short-term, lumbar decompression with coflex® compared with decompression alone in patients with LSS and pronounced LBP at baseline is a safe and effective treatment option that appears beneficial regarding clinical and functional outcomes. However, residual confounding of non-measured covariables may have partially influenced our findings. Also, despite careful inclusion and exclusion of cases the cross registry approach introduces a potential for selection bias that we could not totally control for and that makes additional studies necessary.

Influence of previous surgery on patient-rated outcome after surgery for degenerative disorders of the lumbar spine.

PURPOSE Few studies have used multivariate models to quantify the effect of multiple previous spine surgeries on patient-oriented outcome after spine surgery. This study sought to quantify the effect of prior spine surgery on 12-month postoperative outcomes in patients undergoing surgery for different degenerative disorders of the lumbar spine. METHODS The study included 4940 patients with lumbar degenerative disease documented in the Spine Tango Registry of EUROSPINE, the Spine Society of Europe, from 2004 to 2015. Preoperatively and 12 months postoperatively, patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10 scale). Patients' medical history and surgical details were recorded using the Spine Tango Surgery 2006 and 2011 forms. Multiple linear regression models were used to investigate the relationship between the number of previous surgeries and the 12-month postoperative COMI score, controlling for the baseline COMI score and other potential confounders. RESULTS In the adjusted model including all cases, the 12-month COMI score showed a 0.37-point worse value [95 % confidence intervals (95 % CI) 0.29-0.45; p < 0.001] for each additional prior spine surgery. In the subgroup of patients with lumbar disc herniation, the corresponding effect was 0.52 points (95 % CI 0.27-0.77; p < 0.001) and in lumbar degenerative spondylolisthesis, 0.40 points (95 % CI 0.17-0.64; p = 0.001). CONCLUSIONS We were able to demonstrate a clear "dose-response" effect for previous surgery: the greater the number of prior spine surgeries, the systematically worse the outcome at 12 months' follow-up. The results of this study can be used when considering or consenting a patient for further surgery, to better inform the patient of the likely outcome and to set realistic expectations.