General Session: MIS-2
Presented by: S. Overley - View Audio/Video Presentation (Members Only)
S. McAnany(1), S. Overley(1), M. Anwar(1), H. Cutler(1), J. Guzman(1), J. Kim(1), S. Cho(1), A. Hecht(1), S. Qureshi(1)
(1) The Mount Sinai Hospital, Orthopaedic surgery, New York, NY, United States
Background: Lumbar microdiscectomy is the most commonly performed procedure for patients suffering from radicular pain secondary to a herniated nucleus pulposus (HNP). While the rate of revision microdiscectomy is well established, there are no studies directly addressing the rate of patients whom will eventually require index level fusion following lumbar microdiscectomy.
Purpose: To determine the rate of patients that ultimately require index level fusion following open or minimally invasive lumbar microdiscectomy and identify predictive risk factors.
Study Design: A retrospective review of a series of 174 patients who underwent a single-level microdiscectomy. The outcomes measure of interest was incidence and time after index procedure to revision microdiscectomy, fusion, or both.
Methods: A retrospective review of 174 patients with symptomatic single-level lumbar HNPs underwent microdiscectomy via a mini-open approach (39) or through an MIS dilator tube (135). All patient variables were recorded. Continuous variable were analyzed with independent sample T test and Chi-square analysis were used for categorical data. A multi-variate regression analysis was performed to identify predictive factors for patients that required index level fusion after lumbar microdiscectomy.
Results: There was no difference in patient demographics in the open and MIS groups aside from length of follow-up (60.4 versus 40.03 months) and BMI (24.72 versus 27.21). The rate of revision microdiscectomy was not statistically significant between open and MIS approaches (10.3% vs 10.4%, P = 0.90). The rate of patinets that ultimately required index level fusion approached significance, but was not statistically different between open and MIS approaches (10.3% vs 4.4%, P = 0.17). Multi-variate regression analysis indicated that the need for eventual index level fusion after lumbar microdiscectomy was statistically predicted in smokers and those patients who underwent revision microdisectomy (P-value < 0.05) in both open and MIS groups.
Conclusions: These results represent the first report on the intermediate rate of patients that go on to require index level fusion following lumbar microdiscectomy. Overall, there is a low likelihood of patients ultimately requiring fusion following microdiscectomy with predictors including smoking status and a history of revision microdiscectomy.