The safety and effectiveness of MIDLF during one surgeon’s initial phase: accuracy, clinical outcome, complications and learning curve

Abstract

ObjectiveTo characterize the safety and effectiveness during one surgeon’s initial phases of performing a Midline lumbar fusion by freehand technique based on perioperative parameters.MethodsThe first 90 consecutive patients underwent single level MIDLF, utilized a consistent technique, performed by one surgeon were retrospectively studied. A piecewise regression analysis was performed to evaluate the operation duration based on case number, and to estimate the breakpoint. The early learning period and the late steady phase was divided according to the case number of the breakpoint. Perioperative parameters and clinical data of 2 groups were compared then to elucidate if improvement in operative duration was accompanied by better patient prognosis.ResultsThe inflectional asymptote of the surgeon’s learning curve for MIDLF was achieved at the 40th case. The demographics parameters were similar between the early group of 40 patients and the latter 50. Average surgical time, intraoperative blood loss, length of incision, duration of drainage, postoperative drainage and post-operative hospitalization were significantly less in the late cohort (p<.05). Medial cortical breach was observed in 6/360 cases (4 vs. 2, P>.05), and lateral cortical breach was observed in 35/360 cases (24 vs.11, P<.05). One case of cerebrospinal fluid (CSF) leak, two cases of durotomy and one case of nerve root injury related to the technique was found in the early group, and only one case of durotomy was found in the late group. Post-surgical wound infection was seen in 2.22% (N = 2/90) of patients (2 vs. 0, P>.05). The overall complication incidence decreased alone with the learning curve, and statistical difference was achieved. Furthermore, there was no difference in clinical improvement between the two groups.ConclusionsOur result indicated that technical proficiency in MIDLF was achieved after 40 surgeries. And it is effective to significantly improve the patients’ functional status and relief the pain during one surgeon’s learning process of MIDLF in the treatment of lumbar degenerative disease, even in the initial phase. As the surgeon gains surgical proficiency and familiarity with MIDLF procedure, potential complications could be minimized. Furthermore, our results provided evidence to the excellent performance as an alternative option to traditional pedicle screw fixation.