Study Design Retrospective cohort study. Objectives The main purpose of the present study was to report the incidence and identify predictors of reoperation in patients with lumbar spinal stenosis (LSS) treated with percutaneous endoscopic transforaminal decompression (PETD). Methods This study retrospectively reviewed consecutive patients with LSS who underwent PETD at our center between January 2016 and July 2020. The incidence of reoperations was calculated. We then designed a surgical period-matched case-control study to identify predictors among demographic data, clinical baseline data, and imaging parameters. Results This study identified 496 eligible patients. 33 (6.7%) patients underwent reoperation with a mean follow-up of 3 years, consisting 22 (4.4%) at the index level and 11 (2.2%) at the adjacent levels. There were significant differences in age and age-adjusted Charlson comorbidity index (AACCI) between the two groups, with younger age (P = .004) and lower AACCI (P = .019) in reoperation group. Age was identified as the sole independent predictor (P = .006). The duration of symptoms ≥12 months (P = .034) and the presence of heart problems (P = .012) were recognized as specific predictors among patients younger than 65 years. Conclusions In a mean follow-up of 3 years, the incidence of reoperation in LSS treated with PETD was 6.7%. A younger age was the independent predictor for reoperation. Younger patients with the duration of symptoms ≥12 months or without heart problems were more likely to undergo a second operation. Prospective randomized controlled trials are required to confirm these findings.

Objective: Posterior apophyseal ring fracture (PARF) is an uncommon disorder that is usually accompanied by lumbar disc herniation (LDH). The aim of this study to describe the 8-year experience of performing minimally invasive treatment of PARF, giving particular attention to surgical technique and clinical outcome.Methods: We reviewed 1,324 consecutive patients with LDH seen in our department between 2013 and 2020. Forty-eight patients (3.63%) were enrolled who were diagnosed with PARF associated with LDH and underwent transforminal endoscopic lumbar discectomy (TELD). Mean duration of the final postoperative follow-up was 5.1 years. The control group was comprised of 50 patients diagnosed with LDH without PARF at the same facility. Data on clinical outcomes were analyzed.Results: The mean operation time in the PARF group was 105.4 minutes, which was longer than the mean operation time of the control group (83.9 minutes) (p = 0.001). Surgical complications, including dural tears (6.3%) and surgical instrument rupture (4.2%) were more common in the PARF group (p = 0.025). However, there was no significant difference in the proportion of excellent and good results and recurrence rates between the LDH patients with and those without PARF, respectively.Conclusion: TELD is a safe and effective minimally invasive approach for the treatment of PARF. However, minimally invasive techniques may require longer operation time and steeper learning curve for inexperienced surgeons. The separation and removal of bone fragments, a key step in the procedure, requires patience and care to prevent rupture, residual surgical instruments, and leakage of cerebrospinal fluid.