Yusuke Hori

Posterior corrective surgery with a multilevel transforaminal lumbar interbody fusion and a rod rotation maneuver for patients with degenerative lumbar kyphoscoliosis.

The purpose of this study was to assess the clinical results of posterior corrective surgery using a multilevel transforaminal lumbar interbody fusion (TLIF) with a rod rotation (RR) and to evaluate the segmental corrective effect of a TLIF using CT imaging. The medical records of 15 consecutive patients with degenerative lumbar kyphoscoliosis (DLKS) who had undergone posterior spinal corrective surgery using a multilevel TLIF with an RR technique and who had a minimum follow-up of 2 years were retrospectively reviewed. Radiographic parameters were evaluated using plain radiographs, and segmental correction was evaluated using CT imaging. Clinical outcomes were evaluated with the Scoliosis Research Society Patient Questionnaire-22 (SRS-22) and the SF-36. The mean follow-up period was 46.7 months, and the mean age at the time of surgery was 60.7 years. The mean total SRS-22 score was 2.9 before surgery and significantly improved to 4.0 at the latest follow-up. The physical functioning, role functioning (physical), and social functioning subcategories of the SF-36 were generally improved at the latest follow-up, although the changes in these scores were not statistically significant. The bodily pain, vitality, and mental health subcategories were significantly improved at the latest follow-up (p < 0.05). Three complications occurred in 3 patients (20%). The Cobb angle of the lumbar curve was reduced to 20.3° after surgery. The overall correction rate was 66.4%. The pelvic incidence-lumbar lordosis (preoperative/postoperative = 31.5°/4.3°), pelvic tilt (29.2°/18.9°), and sagittal vertical axis (78.3/27.6 mm) were improved after surgery and remained so throughout the follow-up. Computed tomography image analysis suggested that a 1-level TLIF can result in 10.9° of scoliosis correction and 6.8° of lordosis. Posterior corrective surgery using a multilevel TLIF with an RR on patients with DLKS can provide effective correction in the coronal plane but allows only limited sagittal correction.

Utility of Discography as a Preoperative Diagnostic Tool for Intradural Lumbar Disc Herniation

Preoperative definitive diagnosis of intradural lumbar disc herniation (ILDH) is difficult despite the availability of various neuroradiological investigative tools. We present a case of ILDH diagnosed preoperatively by discography and computed tomography-discography (disco-CT).The patient was a 63-year-old man with acute excruciating right leg pain. Discography and disco-CT demonstrated leakage of the contrast medium into the intradural space. Based on these findings, a right L5 nerve root disturbance caused by ILDH was diagnosed. A right L5 hemi-laminectomy and a dorsal durotomy were performed. The herniated disc was carefully dissected and then completely removed. Three months after surgery, the patient had fully recovered. This report highlights the importance of making a definitive diagnosis of ILDH preoperatively for better surgical planning and improved clinical outcomes. Furthermore, discography and disco-CT are both useful preoperative diagnostic tools for the diagnosis of ILDH.

Impact of Hemodialysis on Surgical Outcomes and Mortality Rate After Lumbar Spine Surgery: A Matched Cohort Study

Introduction Despite ongoing improvements in both dialysis and surgical techniques, spinal surgery in patients undergoing hemodialysis (HD) is a challenge to surgeons because of the high mortality rate. However, no previous studies have examined clinical outcomes after lumbar surgery in HD patients. The purpose of this study is to compare clinical outcomes and complication rates after lumbar spinal surgery in patients with or without hemodialysis. Methods This retrospective, matched cohort study was conducted to compare surgical outcomes between HD vs non-HD patients who underwent lumbar surgery at our hospital. Controls were individually matched to cases at a ratio of 1:2. Clinical outcomes, complications, and mortality rates were compared between the two groups. Results Twenty-nine patients in the HD group and 57 in the non-HD group were included in the current study. Five patients in the HD group died during the follow-up period, whereas no patients died in the non-HD group (mortality rate, 17.2% vs. 0%, P = 0.003). Japanese Orthopaedic Association (JOA) scores were significantly less improved in the HD group than in the non-HD group (11.9 vs. 14.2 preoperatively, P = 0.001; 19.9 vs. 25.1 at final follow-up, P < 0.001). Five patients underwent repeat surgery in the HD group, which was significantly higher than the non-HD group (17.2% vs. 3.5%, P = 0.041). Conclusions The current study indicates that patients undergoing HD had poor outcomes after lumbar spinal surgery. Moreover, 5 of 29 patients died within a mean 2.4-years follow-up. The indications for lumbar spine surgery in HD patients must be carefully considered because of poor surgical outcomes and high mortality rate.

Comparison of minimally invasive decompression and combined minimally invasive decompression and fusion in patients with degenerative spondylolisthesis with instability

Posterior lumbar interbody fusion with cortical bone trajectory (CBT-PLIF) is a form of minimally invasive decompression and fusion, whereas microendoscopic laminotomy (MEL) is a form of minimally invasive decompression surgery. No study has compared the clinical outcomes of the two methods for patients who have degenerative spondylolisthesis (DS) with instability. In this study, CBT-PLIF and MEL were both offered to 64 patients who met the inclusion criteria. Each patient then selected his or her preferred treatment. Twenty patients received CBT-PLIF. They were matched to 30 of the 44 patients receiving MEL based on age, sex, disease duration, and surgical levels. The 20 patients with CBT-PLIF formed the CBT group and the 30 matched patients with MEL formed the MEL group. At 2 years of follow-up, Japanese Orthopaedic Association scores improved to 72.6% and 70.5% in the CBT and MEL groups, respectively. The difference in scores was not statistically significant. Further, improvements in visual analogue scale scores for back and leg symptom did not differ significantly between the two groups. Regarding complications, 1 CBT-group patient (5%) had adjacent-segment degeneration and 7 MEL-group patients (23%) had same-segment degeneration. Three CBT-group patients (15%) and 5 MEL-group patients (16%) required reoperation within the follow-up period. In summary, among patients who had DS with instability, MEL and CBT-PLIF offered comparable clinical outcomes at 2 years of follow-up. Although the rate of segmental degeneration was relatively high in the MEL group, both groups had similar reoperation rates.

Spinopelvic Sagittal Alignment after Microendoscopic Laminotomy in Patients with Lumbar Degenerative Spondylolisthesis

Background and Study Aims Spinopelvic sagittal balance is important in managing lumbar diseases. We evaluated the change in spinal sagittal alignment after microendoscopic laminotomy in patients with low‐grade degenerative spondylolisthesis (DS). Material and Methods We retrospectively reviewed the records of 87 patients who underwent microendoscopic laminotomy. We enrolled 35 patients with DS and 52 patients without DS. Spinopelvic parameters were evaluated, including the sagittal vertical axis (SVA), lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence (PI). Primary outcome was a change in spinopelvic alignment between the baseline and latest follow‐up values (DS group versus non‐DS group). Secondary outcomes were the relationships between improved global sagittal alignment and preoperative spinopelvic parameters. Results Both groups showed significantly alleviated low back pain (LBP), leg pain, and leg numbness. Preoperative SVA and PI were significantly higher in the DS group than in the non‐DS group (p < 0.05). SVA significantly decreased and LL significantly increased in the DS group (p < 0.05), whereas those parameters did not differ significantly from before versus after surgery in the non‐DS group. In both groups, SVA improvement correlated significantly with preoperative SVA (DS: r = 0.702; non‐DS: r = 0.397). There was also a significant intergroup difference in the correlation coefficient (z = 1.98; r = 0.048). Conclusions SVA and LL significantly improved after microscopic laminotomy in patients with low‐grade DS and neurologic symptoms. SVA improvement in the DS group was correlated with preoperative spinopelvic sagittal imbalance. The strength of those correlations was greater in the DS group than in the non‐DS group.

Effect of Different Types of Upper Instrumented Vertebrae Instruments on Proximal Junctional Kyphosis Following Adult Spinal Deformity Surgery: Pedicle Screw versus Transverse Process Hook

Study Design Retrospective comparative study. Purpose To compare the incidence of proximal junctional kyphosis (PJK) between transverse process hooks (TPHs) and pedicle screws (PSs) at the upper instrumented vertebrae (UIV) following adult spinal deformity (ASD) surgery. Overview of Literature The choice of UIV implant type may be important for avoiding PJK; however, few comparative clinical studies have evaluated the incidence of PJK according to the type of UIV implant used in ASD surgery. Methods We retrospectively reviewed 39 consecutive patients with ASD (mean age, 67 years; mean follow-up period, 41 months) who underwent corrective surgery between 2009 and 2013. TPH was used in 17 patients and PS in 22 patients. PJK was defined as the presence of a UIV or UIV±1 fracture, or a change in the proximal junctional angle (PJA) of >20°. Data of patients with TPH and PS were compared. Results The TPH group had a PJK incidence of 17.6% compared with 27.3% in the PS group (p =0.47). In the TPH group, PJK was a result of UIV fracture in one patient, UIV−1 fracture in one patient, and ligamentous failure in one patient. In the PS group, six patients developed PJK because of UIV fracture. No differences in radiographic parameters were found between the two groups. After analyzing the PJA data in the patients with PJK, the changes in PJA were significantly higher in the PS group than in the TPH group (19.0°/5.0°, p =0.04). Conclusions Our results show that using TPH as a UIV implant may not prevent PJK; however, using TPH as the UIV anchor may prevent vertebral collapse if cases of UIV fracture. The increased risk of UIV fracture collapse in the PS group may be a result of a higher mechanical load on UIV when using PS.