DOS 2018

272 · DOS Abstracts Minimal Invasive Spine Surgery - Safety and efficacy A retrospective, single-center observational study in 150 patients. Kelwin Perez Contreras, Søren Fruensgaard, Sasa Randelovich, Gang Chen, Peter Lemche, Carsten Ernst, Thomas Bender, Malene Laursen Spine Unit, Regional Hospital Silkeborg; Spine Unit, Regional Hospital Silkeborg Background: The minimally invasive spine surgery fusions techniques are been used world wide, have been suggested as a safe alternative to open surgery without higher complication rates. In our center, this techniques were used until 2017. We found some complications in our outpatient, and we decided to do this retrospective study with all the 150 patients. Purpose / Aim of Study: The purpose of the current investigation was to evaluate safety and efficacy regarding minimally invasive techniques, i.e., trans- foraminal lumbar interbody fusion (MIS TLIF) and posterolateral lumbar fusion (MIS PLF) in a selected Danish population. Materials and Methods: Consecutive patients undertaking MIS TLIF and MIS PLF in CPK, Silkeborg in the period 2011 - 2017. Data were collected retro- spectively from local hospital records with the help of all surgeons in the spine unit. Outcome measures were complication-rate duringadmission and post dis- charge according to number of fusion levels and a BMI discrimination between the normal and obese patient. Findings / Results: MIS TLIF: n= 67 patients. M/F: 29/38. Median age 42 yr. [25-70]. Complications: nerve injury (1), neuropraxi (1). screw-breakage (1), Superficial Infection (1), Cage migration (1). Revision surgery: 4 decom- pression and 3 implant removeal and refusion MIS PLF: n=83 patients. M/F: 36/47. Median age 46 yr. [20-75] Complications: subcutaneous hematoma (1), Pedicle fracture (1). screw-breakage (4), screw-loosening (5), Both screw breakage and loosening (1), rod-breakage (1). Revision surgery: 5 decompres- sion and 11 implant removeal and refusion Conclusions: The results indicate that one-level MIS TLIF might be a safe in a selected group of patients. MIS PLF technique reveals a high mechanical failure rate, the complication and -reoperation rate was higher in the obese patients. 213.