Search

Residual disc fragments are observed on immediate postoperative magnetic resonance imaging (MRI) in 2.8-15% of patients after percutaneous endoscopic lumbar discectomy (PELD). Considering the known postoperative longitudinal outcomes in patients with residual disc tissue, a 'watchful waiting' strategy may be preferable to immediate re-operation in patients with asymptomatic residual disc material.The aim of the present study was to compare the longitudinal clinical outcomes between PELD patients in whom the complete removal of disc fragments was achieved (complete group) and those in whom residual disc fragments were observed on postoperative MRI (residual group).Retrospective nested case-control study.A total of 225 patients were included (complete group, n=187 and residual group, n=38). Clinical assessments were performed using the visual analog pain score for the leg (VAS-L, x/10) and back (VAS-B, x/10) and the Korean version of the Oswestry Disability Index (K-ODI, x/45). A linear mixed-effects model was used to analyze changes during the first 24 postoperative months.One month after surgery, significant improvements in the VAS-L, VAS-B and K-ODI values were observed and were maintained during the first 24 postoperative months. No differences in these changes were noted between the groups. Early re-operation (during the first 3 postoperative months) was performed in 3 patients in the residual group (7.9%) and in 4 patients in the complete group (2.1%) (P = 0.10).First, the study design was retrospective. Moreover, the number of patients was relatively small and therefore insufficient to achieve robust statistical power. Second, we did not explore the radiological outcomes in patients with asymptomatic residual disc material because follow-up MRI was only obtained to document symptom recurrence.When residual disc tissue is observed in asymptomatic patients, a 'watchful waiting' strategy may be preferable to immediate re-operation. However, an increased early re-operation rate is expected for patients with residual disc tissue.Discectomy, endoscopes, longitudinal studies, patient-reported outcome, percutaneous, reoperation, spine, residual disc.

Background: Some patients with lumbar herniated intervertebral disc disease (HIVD) suffer from both pain and lateral shift or trunk list. In addition to pain, patients have concerns regarding whether trunk list is reversible. Surgical treatment is performed when pain is intractable to conservative management, but a reversal of trunk list is an incidental outcome. Percutaneous lumbar endoscopic discectomy (PELD) is one of the surgical treatment options for lumbar HIVD, but no results concerning its effect on trunk list have been reported. Objectives: The objectives of the present study were to determine the incidence of, and risk factors for, trunk list scoliosis or lateral shift and to report the outcomes of trunk list after PELD. Study Design: Retrospective case study. IRB No. H 1111-025-384 Setting; University medical Center, Seoul, Korea. Methods: We selected 164 patients who were less than 60 years old, complained of unilateral leg pain, and underwent PELD. We measured the maximum trunk shift from the central sacral vertical line (CSVL-max) on preoperative whole spine radiographs and classified trunk list as CSVL-max ≥ 10 mm. CSVL-max was measured on serial radiographs taken at one, 3, 6, and 12 months postoperatively in patients with trunk list. Results: Twenty-nine patients (17.9%) had trunk list (M:F=10:19; mean age, 37.1 ± 11.24 years). Female gender (OR 4.28; 95% CI, 1.49 – 12.3) and HIVD at L4-5 (OR 5.6; 95% CI, 1.8 - 16.7) were risk factors for trunk list. Trunk list was normalized (CSVL-max < 10 mm) in 15 (52%) patients after PELD, and the median time for normalization was 3 – 6 months. Prognostic factors for the recovery of trunk list were not identified. Limitations: Selection bias should be considered in interpreting these results. Conclusion: Trunk list, scoliosis or lateral shift, was observed in 18% of the patients at the time of surgery. Female gender and L4-5 disc herniation were risk factors for trunk list. Trunk list was reversible in more than 50% of patients within 6 months of PELD. Key words: Lumbar, scoliosis, lumbar/sciatic, trunk list, endoscope, disc, discectomy, sciatica, spine, percutaneous endoscopic discectomy

Herniated intervertebral disc disease (HIVD) is a common cause of lower back and leg pain. Percutaneous endoscopic lumbar discectomy (PELD) is indicated when non-surgical treatments such as medication and interventions are intractable. Ruptured discs and loose fragments inside discs are removed during PELD. Nerve root decompression is usually assessed by visualizing the free movement of the traversing nerve root or epidural fat, the free passage of a probe into the epidural space, the depression of the annulus, and the removal of the expected ruptured discs and loose fragments based on preoperative magnetic resonance images (MRI). However, these criteria are subjective, and the quantity of the disc removal necessary for successful outcomes after PELD has not been investigated.The present study investigates the amount of discectomy of PELD and its clinical and radiological outcomes.A retrospective case study (IRB Number H-1611-015-803).University Medical Center, Seoul, Korea.PELD was performed in 109 consecutive patients (M:F = 53:56; mean age, 37.4 years) using the transforaminal or interlaminar route. Ruptured disc fragments were first removed in all patients, and the graspable loose fragments under the disc were removed. After surgery, all removed disc fragments were placed into disposable syringes and manually compressed to measure their volume. The volume of herniated disc outside the disc boundary was calculated in MRI. The measured and calculated disc volumes were retrospectively compared. Clinical success was defined as an improvement in both the Oswestry Disability Index (ODI) and leg pain, as well as no recurrent symptoms. Radiological success was defined as the disappearance of herniated disc material outside the disc boundary based on postoperative MRI taken within one day after surgery. The follow-up period was 7.2 ± 5.2 months.Successful clinical outcomes were obtained in 96/109 (88.1%) patients in a median time of 3 months. Re-operation was performed in 3 patients due to recurrent discs in 2 patients and a residual disc in one patient. Predictors of clinical success were not identified, and the quantity of the removed disc was not associated with the clinical outcome. Radiological success was achieved in 93/109 (85.3%) patients. Of 13 patients with radiological failure, 2 patients showed clinical failure. A logistic regression analysis showed that the relative volume of the removed disc (%) compared with the volume of preoperative herniated disc based on the MRI was the only significant predictor (P0.001; OR = 0.96). When 100% of the calculated disc amount was removed during the operation, the probability of residual disc was 30%. When 131% of the calculated disc amount was removed, the probability of residual disc was 10%.This study employed a retrospective design, and its inherent selection bias and limited statistical power should be considered.The amount of disc removal during PELD was not a significant predictor of clinical success after the primary ruptured fragments were removed. The relative volume of the removed disc based on the preoperative MRI might predict the postoperative MRI.Disc, lumbar vertebra, discectomy, surgery, endoscopy, volume.

The progression of cervical kyphosis due to injury to the facet joints and musculature is a major concern for posterior foraminotomy especially for patients with cervical lordosis of less than 10°. However, cervical hypo-lordosis (cervical lordosis10°) may be improved with the alleviation of pain and muscle spasms, which corresponds with the disappearance of a positive Spurling's test. When surgery is necessary, the spontaneous recovery of cervical curvature may be minimally offset using minimally invasive surgical techniques, such as posterior percutaneous endoscopic cervical foraminotomy (P-PECF).The primary objective was to compare the changes in cervical kinematics between patients with cervical lordosis (≥ 10°, group I) and hypo-lordosis (10°, group II) after P-PECF.This study was a retrospective nested case-control study with the IRB No. H-1210-078-434.University Medical Center, Seoul, Korea.P-PECFs were performed for patients with a radiculopathy due to single-level unilateral cervical foraminal soft-disc herniations or foraminal stenosis with minimal degeneration of the disc/facet joints and a positive Spurling's test. A retrospective nested case-control study was performed for 23 patients with cervical lordosis of ≥ 10° (group I; M:F = 15:8; age, 52.3 ± 9.8 years) and 23 patients with cervical lordosis of10°(group II; M:F = 15:8; age, 46.3 ± 12.7 years). P-PECFs were performed using the methods previously reported, and all patients were discharged the next day without limitations on neck motion. The patients were followed at one, 3, 6, and 12 months postoperatively and yearly thereafter. The follow-up period was 25.8 ± 19.6 months. Clinical outcomes were assessed using the visual analogue pain score of arms. The cervical angles (C2-7, tangential method) were measured on neutral (CA), flexion (CAF), and extension (CAE) lateral radiographs, and range of motion (C-ROM) was calculated by conducting a radiological analysis. A linear mixed model was used to assess the linearity of the changes in cervical curvatures during the postoperative 12 months between the groups.Significant reductions in arm pain and negative results on Spurling's test were initially achieved in 21/23 patients in group I and in 23/23 patients in group II with means of 1.7 ± 0.31 months and 1.09 ± 0.09 months, respectively. Using the mixed effect models, the interactions between group and time were significant for the CA (P = 0.004), CAE (P0.001), and C-ROM (P0.001) but not the CAF (P = 0.392). The CA (adjusted-P0.001), CAE (adjusted-P0.001), and C-ROM (adjusted-P = 0.046) exhibited significant between-group differences at the pre-operation. However, during the follow-up, these parameters were significantly changed in group II, especially during the postoperative 3 months. The CA, CAE, and C-ROM changed by -11.73°, -19.87°, and 20.32°, respectively. Postoperatively, 17/23 patients in group II and 22/23 patients in group I exhibited cervical lordosis of ≥ 10°.This study was retrospective in design, and the inherent selection bias and limited statistical power should be considered.Cervical hypo-lordosis less than 10° may not be a contra-indication for P-PECF when the change of cervical curvature is not a structural change. A larger study is necessary to identify prognostic factors. Key words: Alignment, cervical vertebrae, disc, percutaneous, endoscopes, biomechanical phenomena, surgery, lordosis, kyphosis.

Some patients with lumbar herniated intervertebral disc disease (HIVD) suffer from both pain and lateral shift or trunk list. In addition to pain, patients have concerns regarding whether trunk list is reversible. Surgical treatment is performed when pain is intractable to conservative management, but a reversal of trunk list is an incidental outcome. Percutaneous lumbar endoscopic discectomy (PELD) is one of the surgical treatment options for lumbar HIVD, but no results concerning its effect on trunk list have been reported.The objectives of the present study were to determine the incidence of, and risk factors for, trunk list scoliosis or lateral shift and to report the outcomes of trunk list after PELD.Retrospective case study. IRB No. H 1111-025-384 SETTING; University medical Center, Seoul, Korea.We selected 164 patients who were less than 60 years old, complained of unilateral leg pain, and underwent PELD. We measured the maximum trunk shift from the central sacral vertical line (CSVL-max) on preoperative whole spine radiographs and classified trunk list as CSVL-max ≥ 10 mm. CSVL-max was measured on serial radiographs taken at one, 3, 6, and 12 months postoperatively in patients with trunk list.Twenty-nine patients (17.9%) had trunk list (M:F=10:19; mean age, 37.1 ± 11.24 years). Female gender (OR 4.28; 95% CI, 1.49-12.3) and HIVD at L4-5 (OR 5.6; 95% CI, 1.8-16.7) were risk factors for trunk list. Trunk list was normalized (CSVL-max10 mm) in 15 (52%) patients after PELD, and the median time for normalization was 3-6 months. Prognostic factors for the recovery of trunk list were not identified.Selection bias should be considered in interpreting these results.Trunk list, scoliosis or lateral shift, was observed in 18% of the patients at the time of surgery. Female gender and L4-5 disc herniation were risk factors for trunk list. Trunk list was reversible in more than 50% of patients within 6 months of PELD.