Comparison of spinous process-splitting laminectomy versus posterolateral fusion for lumbar degenerative spondylolisthesis.

BACKGROUND: Although several studies have recently shown that spinous process-splitting laminectomy (SPSL) maintains lumbar spinal stability by preserving posterior ligament components and paraspinal muscles as compared with conventional laminectomy, evidence is scarce on the treatment outcomes of SPSL limited to lumbar degenerative spondylolisthesis. We herein compare the surgical results and global alignment changes for SPSL versus posterolateral lumbar fusion (PLF) without instrumentation for lumbar degenerative spondylolisthesis. METHODS: A total of 110 patients with Grade 1 lumbar degenerative spondylolisthesis who had undergone SPSL (47 patients) or PLF (63 patients) with minimum 1-year follow-up were retrospectively enrolled from a single institutional database. RESULTS: Mean operating time per intervertebral level and intraoperative blood loss per intervertebral level were comparable between the SPSL group and PLF group. Japanese Orthopaedic Association scores, Oswestry disability index, and visual analog scale scores were significantly and comparably improved at 1 year postoperatively in both groups as compared with preoperative levels. The numbers of vertebrae with slip progression to Grade 2 and slip progression of 5% or more at 1 year postoperatively were similar between the groups. In the SPSL group, mean pelvic tilt (PT) was significantly decreased at 1 year postoperatively. In the PLF group, mean lumbar lordosis (LL) was significantly increased, while mean sagittal vertical axis, PT, and pelvic incidence-LL were significantly decreased at 1 year after surgery. CONCLUSIONS: Compared with PLF without instrumentation, SPSL for Grade 1 lumbar degenerative spondylolisthesis displayed comparable results for slip progression and clinical outcomes at 1 year postoperatively.

Does fusion status following posterolateral lumbar fusion in the treatment for stable lumbar degenerative spondylolisthesis affect the long-term surgical outcomes? A propensity score-weighted analysis of consecutive patients.

BACKGROUND: The surgical strategy of lumbar degenerative spondylolisthesis (LDS) is controversial, especially regarding whether or not fusion should be used. Although some reports have indicated that decompression combined with fusion may be better than decompression alone in the treatment of LDS, the effect of fusion status after uninstrumented posterolateral lumbar fusion (PLF) on the outcomes of patients with stable LDS remains unknown. This study aimed to evaluate the surgical outcomes of uninstrumented PLF for stable LDS and clarify whether radiographic fusion status could affect surgical outcomes. METHODS: A total of 93 consecutive patients who had undergone single-level uninstrumented PLF for Meyerding grade I LDS without preoperative dynamic instability with a minimum follow-up period of 5 years were retrospectively studied. Patients were divided into two groups: nonunion (52 patients) and union (41 patients). The primary outcomes were the 5-year percent recovery of postoperative Japanese Orthopaedic Association (JOA) scores, Oswestry Disability Index (ODI), Visual analog scale (VAS) scores, and reoperation rate. The outcome scores were compared between the groups using the inverse probability weighting method using propensity scores. RESULTS: The union and nonunion groups had comparable weighted means of the 5-year postoperative clinical score for the percent recovery of the JOA score (70.2% vs. 71.1%, P = 0.86), ODI (14.5 vs.14.6, P = 0.98), VAS of low back pain (20.3 vs. 18.7 mm, P = 0.72), and VAS of leg pain (24.0 vs. 19.4 mm, P = 0.43). The reoperation rate was 2.4% (one case of adjacent segment pathology) in the union group and 0% in the nonunion group (P = 0.44). CONCLUSION: The fusion status following uninstrumented PLF had no significant effect on the 5-year postoperative clinical outcomes and reoperation rate in patients with Meyerding grade I LDS without dynamic instability.

Protocol: Prospective observational study aiming for micro-elimination of hepatitis C virus in Nagawa town: The Nagawa Project.

BACKGROUND: The World Health Organization has set a goal of hepatitis C virus (HCV) elimination by the year 2030. However, no regions in Japan have succeeded in eradicating HCV. Micro-elimination is an approach to attain hepatitis C eradication in which national eradication goals are applied to specific populations so that viral treatment and control efforts can move forward quickly and efficiently. In order to eradicate HCV from Japan, this study aims to achieve HCV micro-elimination in the town of Nagawa. METHODS AND DESIGN: The Nagawa Project is an ongoing, prospective, multiple-institution, observational study running from April 1, 2021, to March 31, 2024. All residents of Nagawa town, excluding those under 20 years of age, not consenting to the study, or unable to undergo health check-ups due to nursing care needs, will be included. If found to be HCV antibody-positive, the participant will be recommended to see a doctor in consideration of MAC-2 binding protein glycosylation isomer values. Then, the participant will undergo serum HCV RNA measurement with the real-time polymerase chain reaction by an attending physician. If the participant is HCV RNA-positive, he or she will be referred to a hepatologist for further evaluation. In the case of a definitive diagnosis of chronic hepatitis C, direct acting antiviral treatment will be initiated. Through this process, HCV will be systematically micro-eliminated from the region. DISCUSSION: The Nagawa Project will reveal the prevalence of chronic HCV in addition to the HCV eradication rate in Nagawa town towards achieving HCV micro-elimination. TRIAL REGISTRATION: This study is performed by Shinshu University School of Medicine and was registered as UMIN 000044114 on May 6, 2021.

Adjacent segment pathology following posterior lumbar interbody fusion for lumbar degenerative spondylolisthesis: a comparison between minimally invasive and conventional open approach.

BACKGROUND CONTEXT: The minimally invasive (MI) approach in posterior lumbar interbody fusion (PLIF) minimizes the muscle-stripping posterior exposure of the lumbar spine; therefore, it is hypothesized that such benefits would reduce adjacent segment pathology (ASP) development. OBJECTIVE: This study aimed to estimate the incidence of ASP following MI-PLIF. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: A total of 100 patients who had undergone single-level PLIF at the L4/5 level for lumbar degenerative spondylolisthesis were retrospectively studied (MI-PLIF group: 68 patients; conventional open PLIF [O-PLIF] group; 32 patients; average follow-up period: 100.5 months). OUTCOME MEASURES: Incidence of ASP. METHODS: Patients were considered to have operative ASP (OASP) if adjacent segments manifested degenerative lesions that caused clinically significant symptoms requiring surgery. Survival curves were estimated for each group using the Kaplan-Meier method. The study was not externally funded. The authors have no conflicts of interest to declare. RESULTS: Four (5.9%) of the 68 patients in the MI-PLIF group and 6 (18.8%) of the 32 patients in the O-PLIF group experienced OASP during the follow-up period. Kaplan-Meier analysis predicted a disease-free OASP survival rate of 98.5% (95% confidence interval [CI], 95.5%-100%) in the MI-PLIF group and 90.6% (95% CI, 81.1%-100%) in the O-PLIF group at 5 years, and 93.7% (95% CI, 86.8%-100%) in the MI-PLIF group and 71.8% (95% CI, 52.9%-97.5%) in the O-PLIF group at 10 years. MI-PLIF achieved a significantly higher survival rate in OASP than did O-PLIF (p=.04). O-PLIF was associated with a 3.97 times higher risk (odds ratio 3.97, 95% CI, 1.02-15.48; p=.04) of developing OASP in our cohort. CONCLUSIONS: Following MI-PLIF, the rate of OASP was predicted to be 1.5% at 5 years and 6.3% at 10 years. MI-PLIF had a lower incidence of OASP and more favorable clinical outcomes than did O-PLIF.

Spinal cord MRI signal changes at 1 year after cervical decompression surgery is useful for predicting midterm clinical outcome: an observational study using propensity scores.

BACKGROUND CONTEXT: There is little information on the relationship between magnetic resonance imaging (MRI) T2-weighted high signal change (T2HSC) in the spinal cord and surgical outcome for cervical myelopathy. We therefore examined whether T2HSC regression at 1 year postoperatively reflected a 5-year prognosis after adjustment using propensity scores for potential confounding variables, which have been a disadvantage of earlier observational studies. PURPOSE: The objective of this study was to clarify the usefulness of MRI signal changes for the prediction of midterm surgical outcome in patients with cervical myelopathy. STUDY DESIGN/SETTING: This is a retrospective cohort study. PATIENT SAMPLE: We recruited 137 patients with cervical myelopathy who had undergone surgery between 2007 and 2012 at a median age of 69 years (range: 39-87 years). OUTCOME MEASURES: The outcome measures were the recovery rates of the Japanese Orthopaedic Association (JOA) scores and the visual analog scale (VAS) scores for complaints at several body regions. MATERIALS AND METHODS: The subjects were divided according to the spinal MRI results at 1 year post surgery into the MRI regression group (Reg+ group, 37 cases) with fading of T2HSC, or the non-regression group (Reg- group, 100 cases) with either no change or an enlargement of T2HSC. The recovery rates of JOA scores from 1 to 5 years postoperatively along with the 5-year postoperative VAS scores were compared between the groups using t test. Outcome scores were adjusted for age, sex, diagnosis, symptom duration, and preoperative JOA score by the inverse probability weighting method using propensity scores. RESULTS: The mean recovery rates in the Reg- group were 35.1%, 34.6%, 27.6%, 28.0%, and 30.1% from 1 to 5 years post surgery, respectively, whereas those in the Reg+ group were 52.0%, 52.0%, 51.1%, 49.0%, and 50.1%, respectively. The recovery rates in the Reg+ group were significantly higher at all observation points. At 5 years postoperatively, the VAS score for pain or numbnessin the arms or hands of the patients in the Reg+ group (24.7 mm) was significantly milder than that of the patients in the Reg- group (42.2 mm). CONCLUSIONS: Spinal T2HSC improvement at 1 year postoperatively may predict a favorable recovery until up to 5 years after surgery.

A prospective study of recovery from leg numbness following decompression surgery for lumbar spinal stenosis.

BACKGROUND: Residual leg numbness (LN) following lumbar surgery can lower patient satisfaction; however, prospective studies are sparse. The purpose of this study was to evaluate recovery from LN following decompression surgery for lumbar spinal stenosis (LSS). METHODS: A total of 145 patients with LSS were enrolled. All patients underwent decompressive surgery, with or without spinal fusion, followed by a 12 month prospective follow-up. The degree of LN and leg pain (LP) was assessed using the visual analog scale (VAS), a patient-reported outcome measure. RESULTS: Six patients dropped out, and we evaluated 139 patients (average age, 68.1 years). The average VAS-LN scores were 5.9 ± 2.6, 1.8 ± 2.3, 2.0 ± 2.5, 2.1 ± 2.6, 2.2 ± 2.5, and 2.1 ± 2.6, and the average VAS-LP scores were 5.7 ± 2.8, 1.2 ± 1.7, 0.9 ± 1.5, 1.4 ± 2.0, 1.4 ± 2.0, and 1.4 ± 1.9 preoperatively and at 2 weeks, 3, 6, 9, 12 months following the surgery, respectively. Significant improvement in VAS-LN and VAS-LP scores was observed during the first 2 weeks after the surgery. At 12 months after the surgery, the VAS-LN score was significantly greater than the VAS-LP score. The change in the VAS-LN score between the preoperative and 12 month-postoperative values was significantly smaller than that in the VAS-LP score. Multivariate logistic analyses revealed that preoperative symptom duration and preoperative dural sac cross-sectional area (DCSA) were the significant independent predictive factors for residual LN. CONCLUSIONS: Following lumbar decompression surgery, LN improved significantly during the first 2 weeks after surgery. However, the improvement in the VAS-LN score was less than in the VAS-LP score. Patients with longer preoperative symptom duration and narrow preoperative DCSA showed less LN improvement. LEVEL OF EVIDENCE: Level 3.

Predictors of improvement in low back pain after lumbar decompression surgery: Prospective study of 140 patients.

BACKGROUND: Lumbar decompression surgery is often used to treat neurological symptoms of the lower extremity as a result of lumbar disease. However, this method also leads to the improvement of the accompanying low back pain (LBP). We studied the extent of LBP improvement after lumbar decompression surgery without fusion and the associated preoperative factors. METHODS: Patients (n = 140) with lumbar spinal stenosis (n = 90) or lumbar disc herniation (n = 50) were included. To evaluate the change in LBP, VAS scores and the Oswestry disability index scores were measured before surgery and 2 weeks, 3 months, and 6 months after surgery. The predictors of residual LBP were investigated using logistic regression analyses. RESULTS: In total, 140 patients were examined. The VAS scores for LBP before surgery and 2 weeks, 3 months, and 6 months after surgery were 4.4 ± 3.0 (mean ± standard deviation), 1.1 ± 1.5, 1.3 ± 1.8, and 1.9 ± 2.2, respectively. LBP significantly improved 2 weeks after surgery (P < 0.001), stabilized between 2 weeks and 3 months after surgery, but was significantly aggravated 3-6 months after surgery (P < 0.001). At 6 months after surgery, 67 (47.9%) patients had a VAS score of >1. The predictors of residual LBP included severe preoperative LBP, degenerative scoliosis and the size of the Cobb angle. The independent predictors, determined by multivariate analysis were degenerative scoliosis and the size of the Cobb angle. CONCLUSIONS: LBP was alleviated at 2 weeks after lumbar decompression surgery for lumbar disc herniation and lumbar spinal stenosis. The predictors of residual LBP after decompression included more severe LBP at baseline, degenerative scoliosis and the size of Cobb angle. LEVEL OF EVIDENCE: Level 3.

Surgical Site Infections Caused by Methicillin-resistant Staphylococcus epidermidis After Spinal Instrumentation Surgery.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine relevant demographics, clinical presentations, and outcomes of surgical site infections (SSIs) after spinal instrumentation (SI) surgery caused by methicillin-resistant Staphylococcus epidermidis (MRSE). SUMMARY OF BACKGROUND DATA: This is the first study looking specifically at MRSE-related SSIs after SI surgery. METHODS: We performed a retrospective review of patients with MRSE-related SSIs from 665 consecutive cases of SI surgery performed between 2007 and 2014 at our institution. RESULTS: During the study period, SSIs occurred in 21 patients. MRSE was isolated from cultures obtained from surgical wounds in nine of the 21 patients (43%). There were four males and five females with a mean age of 63.9 ±â€Š15.1 years. Six patients presented with inflammatory signs, such as wound drainage, pyrexia, erythema, and elevated C-reactive protein. Three patients did not have signs of infection, but had early implant failure, and were diagnosed by positive cultures collected at the time of revision surgery. The mean time from index surgery to the diagnosis of infection was 23.6 days (range, 7-88 days). In one patient, the implant was removed before antibiotic treatment was administered because of implant failure. Eight patients were managed with antibiotics and implant retention. During the follow-up period, MRSE-related SSIs in seven of the eight patients were resolved with implant retention and antibiotics without the need for further surgical intervention. One patient did not complete the antibiotic course because of side effects, and implant removal was required to control the infection. CONCLUSION: Early detection, surgical debridement, and administration of appropriate antibiotics for a suitable duration enabled infection control without the need for implant removal in the treatment of MRSE-related SSI after SI surgery. LEVEL OF EVIDENCE: 4.

Single-stage surgery for compressive thoracic myelopathy associated with compressive cervical myelopathy and/or lumbar spinal canal stenosis.

PURPOSE: The clinical impact of the coexistence of compressive cervical myelopathy (CM) and/or lumbar spinal canal stenosis (LCS) with compressive thoracic myelopathy (TM) remains unknown. The purpose of this study was to examine the incidence, clinical pictures, and surgical outcomes of patients with compressive TM and the coexistence of compressive CM and/or LCS. METHODS: We retrospectively reviewed 50 patients (18 women and 32 men; mean age 68.4 years) who underwent decompression surgery for TM. Mean follow-up period was 44 months. The incidence and clinical features of the coexistence of CM and/or LCS were investigated. The surgical outcomes after single-stage multilevel decompression surgery were also examined using the Japanese Orthopedic Association (JOA) scores. RESULTS: Of 50 patients, 35 had concurrent CM and/or LCS (combined group), and the remaining 15 only had TM (T group). No significant differences were found with regard to sex, the etiology of TM, or the level of thoracic stenosis between the groups; however, the patients' age and preoperative JOA scores in the combined group were significantly higher than those in the T group. In both groups, the JOA score at the final follow-up significantly improved compared to the preoperative JOA score. CONCLUSIONS: About 70 % of patients who underwent surgery for TM had concurrent CM and/or LCS, and they were initially diagnosed with CM or LCS. Single-stage multilevel decompression surgery for TM with concurrent CM and/or LCS is comparable to thoracic only surgery with regard to complications and surgical results, and it is well tolerated in elderly patients.

Preoperative spinal cord damage affects the characteristics and prognosis of segmental motor paralysis after cervical decompression surgery.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To test the hypothesis that preoperative spinal cord damage affects postoperative segmental motor paralysis (SMP). SUMMARY OF BACKGROUND DATA: SMP is an enigmatic complication after cervical decompression surgery. The cause of this complication remains controversial. We particularly focused on preoperative T2-weighted high signal change (T2HSC) on magnetic resonance imaging in the spinal cord, and assessed the influence of preoperative T2HSC on SMP after cervical decompression surgery. METHODS: A retrospective review of 181 consecutive patients (130 males and 51 females) who underwent cervical decompression surgery was conducted. SMP was defined as development of postoperative motor palsy of the upper extremities by at least 1 grade in manual muscle testing without impairment of the lower extremities. The relationship between the locations of T2HSC in preoperative magnetic resonance imaging and SMP and Japanese Orthopedic Association score was investigated. RESULTS: Preoperative T2HSC was detected in 78% (142/181) of the patients. SMP occurred in 9% (17/181) of the patients. Preoperative T2HSC was not a significant risk factor for the occurrence of SMP (P = 0.682). However, T2HSC significantly influenced the severity of SMP: the number of paralyzed segments increased with an incidence rate ratio of 2.2 (P = 0.026), the manual muscle score deteriorated with an odds ratio of 8.4 (P = 0.032), and the recovery period was extended with a hazard ratio of 4.0 (P = 0.035). In patients with preoperative T2HSC, Japanese Orthopaedic Association scores remained lower than those in patients without T2HSC throughout the entire period including pre- and postoperative periods (P < 0.001). CONCLUSION: Preoperative T2HSC was associated with worse severity of SMP in patients who underwent cervical decompression surgery, suggesting that preoperative spinal cord damage is one of the pathomechanisms of SMP after cervical decompression surgery. LEVEL OF EVIDENCE: 3.

The effect of a prostaglandin E1 derivative on the symptoms and quality of life of patients with lumbar spinal stenosis.

BACKGROUND: Quality of life (QOL) is a concern for patients with lumbar spinal stenosis (LSS). In this study, QOL was examined using the 5-item EuroQol (EQ-5D). METHODS: QOL and activities of daily living (ADL) were surveyed for 91 patients who visited 18 medical institutions in our prefecture and were diagnosed with LSS-associated intermittent claudication. A second survey was performed after ≥6 weeks for 79 of the subjects to evaluate therapy with limaprost (an oral prostaglandin E1 derivative) or etodolac (an NSAID). Symptoms, maximum walking time, QOL, ADL items, and relationships among these variables were investigated for all 91 patients. Leg pain, leg numbness, and low back pain while walking were surveyed by use of VAS scores (0-100). RESULTS: Leg pain, leg numbness, and low back pain while walking (VAS ≥25) were present in 83.5, 62.6, and 54.9 % of the patients in the first survey, and approximately half of the patients had a maximum walking time <15 min. The mean EQ-5D utility value for QOL was 0.59 ± 0.12. This value was significantly associated with maximum walking time (p = 0.030) based on classification of patients into groups with walking times <7.5, 7.5-15, 15-30, and >30 min, showing that maximum walking time affected health-related QOL. Of the 79 patients who completed the second survey, 56 had taken limaprost and 23 (control group) had received etodolac. Limaprost improved possible walking time, reduced ADL interference, and significantly increased the EQ-5D utility score, whereas no significant changes occurred in the control group. Maximum walking time was prolonged by ≥10 min and the EQ-5D utility value was improved by ≥0.1 points in significantly more patients in the limaprost group than in the control group. CONCLUSION: According to the findings of this survey, at an average of 8 weeks after administration limaprost improved symptoms, QOL, and ADL in LSS patients whereas treatment with an NSAID reduced pain but did not have any other effects.

Tranexamic acid reduces perioperative blood loss in cervical laminoplasty: a prospective randomized study.

STUDY DESIGN: A prospective randomized comparative study. OBJECTIVE: To evaluate the effect of tranexamic acid (TXA) on decreasing perioperative blood loss in cervical laminoplasty, in which the surgical procedure is identical in all cases. SUMMARY OF BACKGROUND DATA: TXA, an inhibitor of fibrinolysis, has proven to be effective in reducing perioperative blood loss in patients undergoing total hip and knee arthroplasty. However, only a limited number of well-controlled spinal surgery trials have been conducted due to heterogeneity in the performed surgical procedures. METHODS: Forty consecutive patients with cervical compressive myelopathy were prospectively randomized into groups that received 15 mg/kg body weight of TXA or placebo intravenously before the skin incision was made. "French-door" cervical laminoplasty from C3 to C6 was performed for all patients by using a consistent procedure. Intraoperative and postoperative blood loss was compared between the groups. The surgery and follow-up were conducted at a single institution. RESULTS: There were no statistically significant differences between the TXA and control groups in terms of age, sex, body mass index, and operating time. Intraoperative blood loss in the TXA group (49.1 ± 30.6 mL) was not significantly different from that in the control group (63.4 ± 53.0 mL, P = 0.30). However, in the TXA group, postoperative blood loss during the first 16 hours was reduced by 37% as compared to the control group (132.0 ± 45.3 vs. 211.0 ± 41.5 mL; P < 0.01). The total blood loss (intraoperative plus postoperative blood loss during the first 40 hours) in the TXA group (264.1 ± 75.1 mL) was significantly lower than that in the control group (353.9 ± 60.8 mL, P < 0.01). No thromboembolic events or complications occurred in either group. CONCLUSION: TXA significantly reduced perioperative blood loss, primarily through a reduction in postoperative blood loss, in cervical laminoplasty.

Recovery process following cervical laminoplasty in patients with cervical compression myelopathy: prospective cohort study.

STUDY DESIGN.: Prospective cohort study. OBJECTIVE.: To investigate the recovery process after laminoplasty in patients with cervical myelopathy, and the effects of patient age and duration of symptoms before surgery on the recovery process. SUMMARY OF BACKGROUND DATA.: The surgical results of laminoplasty for cervical myelopathy have been well documented, but there have been few reports on the recovery process after cervical laminoplasty. METHODS.: The study group consisted of 98 patients who underwent double-door laminoplasty for cervical myelopathy. All cases were followed for a minimum of 5 years. The JOA score, 10 seconds grip and release test (10-second test), and grasp strength were evaluated at "fixed points" after surgery, and the recovery process in each subject was assessed. The maximum recovery time point, defined as the time point when the value just reached a plateau after surgery, was evaluated in each subject.Patients were divided into 2 groups by age (<70 years and > or = 70 years) or duration of symptoms before surgery (<1 year and > or = 1 year), and the effects of these factors on surgical results were investigated. RESULTS.: The preoperative values of all parameters significantly improved 5 years after surgery. The JOA score reached a plateau earlier (8.7 months) than did the grasp strength (21.7 months) and 10-second test (25.6 months). The maximum recovery time point of the JOA score was statistically late in the elder group (> or =70 years) compared to the younger group (<70 years). The recovery rates of the JOA score and the degree of recovery for the 10-second test in patients with symptoms lasting <1 year were statistically greater than those in patients with symptoms lasting > or =1 year. CONCLUSION.: The functional status assessed by the JOA score recovered within 1 year after surgery but further recovery can be expected up to 2 years after surgery. The comparative study suggested that patient age influenced the process of recovery, and the duration of symptoms before surgery influenced the degree of recovery.

Mini-open versus conventional open posterior lumbar interbody fusion for the treatment of lumbar degenerative spondylolisthesis: comparison of paraspinal muscle damage and slip reduction.

STUDY DESIGN: A comparative analysis of paraspinal muscle damage and radiographic parameters after mini-open and conventional open posterior lumbar interbody fusion (PLIF). OBJECTIVE: To determine whether mini-open PLIF decreases paraspinal muscle damage and yields the same radiographic results as those in conventional open PLIF. SUMMARY OF BACKGROUND DATA: Compared with conventional open PLIF, mini-open PLIF using a paramedian approach reduces intraoperative hemorrhage and decreases postoperative back pain. However, whether the latter produces less paraspinal muscle damage than the former remains unclear. No comparative study has investigated slip reduction and segmental lordosis at the fusion level in the 2 techniques. METHODS: We studied 20 patients (10 in each group) who had undergone single-level conventional (midline approach) or mini-open (bilateral Wiltse approach) PLIF with pedicle screws and interbody cages at the L4-L5 level for lumbar degenerative spondylolisthesis. The rate of improvement in the Japanese Orthopedic Association score; radiographic parameters, including %slip; segmental lordotic angle at the L4-L5 level; and fusion rate were examined. Postoperative multifidus (MF) atrophy and degeneration were evaluated using magnetic resonance imaging. RESULTS.: No significant differences were detected between the 2 groups with respect to the rate of improvement in the Japanese Orthopedic Association score, segmental lordotic angle, and fusion rate. Both groups showed significant reduction in %slip after surgery. The degree of MF atrophy and the increase in T2-signal intensity in the MF muscle after mini-open PLIF were significantly lesser than those following open PLIF. CONCLUSION: Mini-open PLIF is safe and effective. Mini-open PLIF was less invasive than open PLIF with regard to the MF muscle.

Characteristics of L3 nerve root radiculopathy.

BACKGROUND: In degenerative lumbar spinal disease with nerve root compression, the L5 and S1 nerve roots are the most often affected and the L3 nerve root is involved infrequently. The purpose of this study was to investigate the characteristics of L3 nerve root radiculopathy. METHODS: Seventeen consecutive patients with L3 radiculopathy were treated. The symptomatic nerve roots were determined by the pain distribution, the neurologic findings, and selective nerve root injection. The clinical characteristics and outcomes of these patients were assessed retrospectively. RESULTS: The average age was 76 years. The spinal diseases that were associated with L3 radiculopathy were lumbar canal stenosis in 6 patients, lumbar extraforaminal stenosis and lumbar disk herniation in 5 each, and lumbar canal stenosis with degenerative scoliosis in 1. The patients' symptoms were thigh pain in 12 patients, and hip or knee pain in 5. Four patients were nonambulatory because of severe pain. Although a sensory disturbance was reported in 9 patients, motor weakness was present in 2. Selective nerve root injection was completely effective in 10 patients. Six had decompressive surgery and/or fusion followed by a favorable outcome. Four patients were misdiagnosed and received conservative treatment for hip and/or knee joint diseases. CONCLUSIONS: L3 radiculopathy was characterized by various lower limb pain and neurologic deficit. Selective nerve root injection was effective for most patients. In elderly patients who do not respond to treatment for hip and/or knee joint diseases, L3 nerve root radiculopathy should be considered as the cause of lower limb pain.

Union versus nonunion after posterolateral lumbar fusion: a comparison of long-term surgical outcomes in patients with degenerative lumbar spondylolisthesis.

It has been reported that in patients undergoing posterolateral lumbar fusion (PLF), the fusion status is not related to the short-term operative results. To determine whether the fusion status influences the long-term operative results of PLF, we retrospectively examined the surgical outcomes of uninstrumented PLF for a minimum of 8 years (average, 9.5 years), by comparing cases exhibiting union with those exhibiting nonunion. Uninstrumented PLF was performed for the treatment of lumbar canal stenosis (LCS) with degenerative spondylolisthesis. Since nine patients were lost to final follow-up, the study included 42 patients, and the follow-up rate was 82.4%. The mean age of the patients was 64.1 years (range 46-77 years). Eight patients exhibited fusion at the L3-4 level and 34 patients, at the L4-5 level. The fusion status was assessed using plain radiographs. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scores. Nonunion was noted in 26% (11/42) of the patients. There were no statistically significant differences between the groups exhibiting union and nonunion with respect to age, sex, preoperative JOA score, or preoperative lumbar instability. The union group achieved better operative results than the nonunion group at the 5-year and final follow-up (P = 0.006 and 0.008, respectively) although there was no significant difference in the percent recovery at 1 and 3-year follow-up (P = 0.515 and 0.506, respectively). A stepwise regression analysis revealed that the best combination of predictors for percent recovery at the time of final follow-up included the fusion status and the presence of comorbid disease. The results indicate that the fusion status following PLF is a critical factor influencing the long-term but not short-term operative results in the treatment of LCS with degenerative spondylolisthesis.

Pro-inflammatory and anti-inflammatory cytokine increases after spinal instrumentation surgery.

We investigated the effects of instrumentation on postoperative inflammatory reaction and identified standard changes in serum cytokine concentrations after spinal surgery. Pro-inflammatory cytokines [interleukin (IL)-6 and IL-8] and anti-inflammatory cytokines [IL-10, IL-1 receptor antagonist (ra), and soluble tumor necrosis factor receptors (sTNF-R) I and II] were assayed in serum from seven patients with lumbar spinal posterior decompression, six with spinal decompression and posterolateral fusion without instrumentation and seven with spinal decompression and posterolateral fusion with instrumentation. All cytokines after spinal instrumentation increased significantly more than in other groups on postoperative days 0 and 1. Seven days after SI, IL-6, -8, and -10 had normalized, but IL-1ra and sTNF-RI and sTNF-RII remained elevated. Both pro-inflammatory and anti-inflammatory cytokines were enhanced by implants in the acute phase, whereas only anti-inflammatory cytokines were enhanced by instruments in the subacute phase.