** OUTCOMES OF POSTERIOR DECOMPRESSION AND FUSION WITH AND WITHOUT INSTRUMENTATION FOR LUMBAR SPINAL STENOSIS WITH DEFORMITY: AN INNER CITY TEACHING INSTITUTION RETROSPECTIVE STUDY

OUTCOMES OF POSTERIOR DECOMPRESSION AND FUSION WITH AND WITHOUT INSTRUMENTATION FOR LUMBAR SPINAL STENOSIS WITH DEFORMITY: AN INNER CITY TEACHING INSTITUTION RETROSPECTIVE STUDY John M. Olsewski, MD; Edouard F. Armour, MD; Hilary Umans, MD Bronx, New York, USA 55 consecutive patients of the same surgeon and same institution with lumbar spinal stenosis and spine deformity (spondylolisthesis. retrolisthesis, scoliosis) treated surgically with both decompression and fusion were retrospectively reviewed for the affect of instrumentation on surgical and clinical results. Group I consisted of 33 patients (18 male, 15 female) with a mean age of 53.4 years, all of whom had pedicle screw fixation as an adjunct to their fusions. Group II consisted of 22 patients (11 male, 11 female) with a mean age of 62.3 years, and had no internal fixation along with their fusions. Minimum follow–up was 24 months with a mean of 40.4 +/– 14.1 months for Group I and a mean of 33.6 +/– 8.2 months for Group II. All patients had failed a minimum of six months of non–operative treatment (physical therapy, NSAID'S, epidural steroids), with a mean time to surgical intervention of 9.1 months. Medical comorbidities averaged 1.1 for Group I and 1.3 for Group II. Evidence of arthrodesis or pseudoarthrosis was graded blindly by an independent bone radiologist. Patient satisfaction for both preoperative and postoperative leg pain as well as back pain was graded via visual analog scale. Statistical analysis was via Student's t–test. Group I had a mean improvement in leg pain postoperatively of 52.3% (8.8 to 4.2, p < 0.05), and a mean improvement in back pain of 47.8% (9.0 to 4.7, p < 0.05). The pseudoarthrosis rate in Group I was 15.2% (5/33). Group II had a mean improvement in leg pain postoperatively of 67.1% (7.9 to 2.6, p < 0.05), and a mean improvement in back pain of 59.2% (8.1 to 3.3, p < 0.05). The pseudoarthrosis rate in Group II was 22.7% (5/22). Complications in Group I were 24% and included 2 wound seromas, 2 deep wound infections, 2 dural tears, one transient nerve root deficit and 1 failed hardware. Complications in Group II were 14% and included 2 dural tears and 1 deep wound infection. Group I mean age was statistically younger (p < 0.05) than Group II. There was a correlation between pseudoarthrosis and less satisfactory results in Group I (p<0.05), but not in Group II. There was no correlation between results and Workman's Compensation status. There were no correlations between comorbidities, including smoking, and pseudoarthrosis or unsatisfactory result rates. Instrumentation improved fusion rate in patients undergoing decompression and fusion for spinal stenosis with deformity, but had no statistical affect on clinical results. There was a trend towards a higher complication rate in the instrumented group, especially with regards to wound complications. The FDA has not cleared a drug and/or medical device for the use described in this presentation. (i.e., the drug or medical device is being discussed in an “off–label: use).