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.

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.

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.