Article Figures & Data
Figures
- Figure 1
The entry point of endoscope for L4 spondylolysis (L4-L5 spondylolisthesis) is the L3-L4 interlaminar window.
- Figure 2
The bony hook is the hook-like remnant of the proximal deficient lamina of the L5 lamina below the pars defect in L5-S1 spondylolisthesis, which compresses the L5 exiting nerve root (red arrow).
- Figure 3
Steps of percutaneous endoscopic pars decompression in L5 spondylolysis (L5-S1 spondylolisthesis). (A) The facet joint of L4-L5 is identified. (B, C) The endoscope cannula is moved to the caudal region adjacent to the facet joint to find the pars defect of L5. (D) The soft tissue and fibrocartilaginous mass in the gap are removed with a burr. (E) After the gap is clear, the S1 traversing nerve is identified. (F) The bony hook below the gap is identified and removed using a Kerrison rongeur until the L5 exiting nerve root is free.
- Figure 4
The red arrow indicates L5 pars defect. The iliolumbar ligament binds between the L5 transverse process and the ilium (white arrow).
- Figure 5
Comparison of pre- and postoperative magnetic resonance images of L5 spondylolysis in a patient who underwent percutaneous endoscopic right L5 pars decompression. (A) The pars defect at L5 observed in a lateral radiograph. (B, C) The right L5 pars defect and L5 exiting nerve root compression in the L5-S1 intervertebral foramen. (D, E) The right L5 exiting nerve root is free after surgery.
Tables
Demographics N = 11 Gender, men:women 6:5 (54.55%:45.45%) Age, y, mean ± SD 62.45 ± 10.65 Follow-up period, mo, mean ± SD 22.64 ± 15.40 Spondylolysis alone 5 (45.45%) L3-L4 and L4-L5 spondylolysis 1 L5-S1 spondylolysis 4 Spondylolysis with spondylolisthesis 6 (54.54%) Grade 1 spondylolisthesis L3-L4 1 Grade 1 spondylolisthesis L4-L5 1 Grade 1 spondylolisthesis L5-S1 3 Grade 2 spondylolysis L5-S1 1 Level of Decompression n (%) L3-L4 1 (9%) L4-L5 1 (9%) L5-S1 7 (64%) L3-L4 and L4-L5 1 (9%) Bilateral L5-S1 1 (9%) - Table 3
Comparison of clinical outcomes and slippage percentage of interlaminar percutaneous endoscopic pars decompression between the preoperative and postoperative periods.
Clinical Outcome Preoperative Postoperative P Value Visual analog scale for leg pain 5.18 ± 3.34 0.82 ± 0.98 0.007 Oswestry Disability Index 41.72 ± 19.24 17.78 ± 12.26 0.005 Percent slippage 8.03 ± 11.27 7.42 ± 9.36 1.000 Note: The variables were compared using the Wilcoxon signed-rank test. The P values were determined to be significant at the 0.05 level.
- Table 4
Improvement rate for VAS and ODI scores after percutaneous endoscopic interlaminar pars decompression.
Improvement Rate VAS for Leg Pain, n (%) ODI, n (%) 76%‒100% 6 (54.55%) 3 (27.28%) 51%‒75% 4 (36.36%) 4 (36.36%) 26%‒50% 1 (9.09%) 2 (18.18%) 0%‒25% 0 2 (18.18%) Abbreviations: ODI, Oswestry Disability Index; VAS, visual analog scale.
- Table 5
Comparison of VAS and ODI improvement between spondylolysis alone and spondylolysis with spondylolisthesis after percutaneous endoscopic pars decompression.
Outcome Measure Spondylolysis Alone (n = 5), Mean ± SD Spondylolysis With Spondylolisthesis (n = 6), Mean ± SD P Value VAS improvement 87.00% ± 18.57% 53.98% ± 43.91% 0.154 ODI improvement 81.91% ± 16.97% 27.57% ± 21.45% 0.001 Abbreviations: ODI, Oswestry Disability Index; VAS, visual analog scale.
Note: An independent sample t test was used to compare the results. P values <0.05 were considered to be statistically significant.
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