Characterization and Risk Factor Analysis for Recurrence Following Microendoscopic Diskectomy for Lumbar Disk Herniation

Background and Study Aims Microendoscopic diskectomy (MED) has become an established minimally invasive procedure in surgical treatment for lumbar disk herniation (LDH). LDH recurrence following surgery is also an important problem in MED because the risk of LDH recurrence may surpass the advantages of MED. The purpose of this study was to investigate the characteristics of recurrence following MED for LDH and identify the risk factors for a recurrence. Materials and Methods A total of 163 patients who underwent MED for LDH and could be followed for a minimum of 1 year after surgery were enrolled in this study (follow-up [FU] rate: 79.9%). We investigated the characteristics of LDH recurrence and conducted a comparative study between the patient groups with and without recurrence to identify the risk factors for the recurrence. Results The recurrence of LDH was observed in 19 patients (11.7%) during a mean of 38 months FU. Although the mean length of time from MED to recurrence was 19.2 months, 36.8% of the LDH recurrence occurred in the first 3 months following MED. Eleven patients were treated successfully by conservative treatments, and the remaining eight patients had to undergo revision surgery (MED in five patients, microdiskectomy in one, and instrumented fusion in two). In the analysis of risk factors for the recurrence, the presence of diabetes mellitus (DM) was significantly correlated with the recurrence (p = 0.0027). Conclusions The recurrence rate following MED for LDH was equivalent to those of previous reports of conventional and microscopic diskectomy. However, a third of the LDH recurrences occurred in the first 3 months after MED. We should pay attention to LDH recurrence at an early phase following MED and recognize the presence of DM as a risk factor for LDH recurrence.