Histology and chronological magnetic resonance images of congenital spinal deformity: An experimental study in mice model

BACKGROUND

The natural history of the congenital spinal deformity and its clinical magnitude vary widely in human species. However, we previously reported that the spinal deformities of congenital scoliosis mice did not progress throughout our observational period according to soft X-ray and MRI data. In this study, congenital vertebral and intervertebral malformations in mice were assessed via magnetic resonance (MR) and histological images.

METHODS

Congenital spinal anomalies were chronologically assessed via soft X-ray and 7 T MR imaging. MR images were compared to the histological images to validate the findings around the malformations.

RESULTS

Soft X-ray images showed the gross alignment of the spine and the contour of the malformed vertebrae, with the growth plate and cortical bone visible as higher density lines, but could not be used to distinguish the existence of intervertebral structures. In contrast, MR images could be used to distinguish each structure, including the cortical bone, growth plate, cartilaginous end plate, and nucleus pulposus, by combining the signal changes on T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI). The intervertebral structure adjacent to the malformed vertebrae also exhibited various abnormalities, such as growth plate and cartilaginous end plate irregularities, nucleus pulposus defects, and bone marrow formation. In the chronological observation, the thickness and shape of the malformed structures on T1WI did not change.

CONCLUSIONS

Spinal malformations in mice were chronologically observed via 7 T MRI and histology. MR images could be used to distinguish the histological structures of normal and malformed mouse spines. Malformed vertebrae were accompanied by adjacent intervertebral structures that corresponded to the fully segmented structures observed in human congenital scoliosis, but the intervertebral conditions varied. This study suggested the importance of MRI and histological examinations of human congenital scoliosis patients with patterns other than nonsegmenting patterns, which may be used to predict the prognosis of patients with spinal deformities associated with malformed vertebrae.

Anterior fusion surgery with overcorrection in the treatment of adolescent idiopathic scoliosis with Lenke 1 AR curve type: how to achieve overcorrection and its effect on postoperative spinal alignment

BACKGROUND

The efficacy of anterior fusion with overcorrection in the instrumented vertebra for Lenke 1 AR type curves has been reported, but how to achieve overcorrection and how overcorrection affects spinal alignment are unclear. The purpose of this study was to identify the factors that cause overcorrection, and to investigate how overcorrection affects postoperative spinal alignment in the surgical treatment of Lenke 1 AR type curves.

METHODS

Patients who had anterior surgery for a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) type scoliosis and minimum 2-year follow-up were included. The radiographic data were measured at preoperative, postoperative 1 month, and final follow-up. The UIV-LIV Cobb angle was determined as the Cobb angle between the upper instrumented vertebra (UIV) and the lower instrumented vertebra (LIV), and a negative number for this angle was considered overcorrection. The screw angle was determined to be the sum of the angle formed by the screw axis and the lower and upper endplates in the LIV and UIV, respectively. The change (Δ) in the parameters from postoperative to final follow-up was calculated. The relationships between the UIV-LIV Cobb angle and other radiographic parameters were evaluated by linear regression analyses.

RESULTS

Fourteen patients met the inclusion criteria. Their median age was 15.5 years, and the median follow-up period was 53.6 months. The median UIV-LIV Cobb angle was -1.4° at postoperative 1 month. The median screw angle was 4.7°, and overcorrection was achieved in 11 (79%) cases at postoperative 1 month. The screw angle (r2 = 0.42, p = 0.012) and Δ FDUV-CSVL (the deviation of the first distal uninstrumented vertebra from the central sacral vertical line, r2 = 0.53, p = 0.003) were significantly correlated with the UIV-LIV Cobb angle.

CONCLUSIONS

Screw placement in the UIV and LIV not parallel to the endplate, but angled, was an effective method to facilitate overcorrection in the instrumented vertebrae. The results of the present study suggest that overcorrection could bring spontaneous improvement of coronal balance below the instrumented segment during the postoperative period.

Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients

PURPOSE

This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications.

METHODS

This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods.

RESULTS

Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%).

CONCLUSIONS

From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Preoperative Symptom Duration Influences Neurological Recovery and Patient-Reported Outcome Measures After Surgical Treatment of Cervical Ossification of the Posterior Longitudinal Ligament

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

To investigate the effect of preoperative symptom duration on neurological recovery for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

The optimal timing to perform surgery in the setting of cervical OPLL remains unknown. It is important to know the influence of symptom duration on postoperative outcomes to facilitate discussions regarding the timing of surgery.

PATIENTS AND METHODS

The study included 395 patients (291 men and 104 women; mean age, 63.7 ± 11.4 yr): 204 were treated with laminoplasty, 90 with posterior decompression and fusion, 85 with anterior decompression and fusion, and 16 with other procedures. The Japanese Orthopedic Association (JOA) score and patient-reported outcomes of the JOA Cervical Myelopathy Evaluation Questionnaire were used to assess clinical outcomes preoperatively and 2 years after surgery. Logistic regression analysis was used to identify factors associated with the achievement of minimum clinically important difference (MCID) after surgery.

RESULTS

The recovery rate was significantly lower in the group with symptom duration of ≥5 years compared with the groups with durations of <0.5 years, 0.5 to 1 year, and 1 to 2 years. Improvement of JOA Cervical Myelopathy Evaluation Questionnaire in the upper extremity function score ( P < 0.001), lower extremity function ( P = 0.039), quality of life ( P = 0.053), and bladder function ( P = 0.034) were all decreased when the symptom duration exceeded 2 years. Duration of symptoms ( P = 0.001), age ( P < 0.001), and body mass index ( P < 0.001) were significantly associated with the achievement of MCID. The cutoff value we established for symptom duration was 23 months (area under the curve, 0.616; sensitivity, 67.4%; specificity, 53.5%).

CONCLUSIONS

Symptom duration had a significant impact on neurological recovery and patient-reported outcome measures in this series of patients undergoing surgery for cervical OPLL. Patients with symptom duration exceeding 23 months may be at greater risk of failing to achieve MCID after surgery.

LEVEL OF EVIDENCE

3.

Comparison of Surgical Outcomes of Anterior and Posterior Fusion Surgeries for K-line (-) Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

The objective of this study is to compare the surgical outcomes of anterior and posterior fusion surgeries in patients with K-line (-) cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Although laminoplasty is effective for patients with K-line (+) OPLL, fusion surgery is recommended for those with K-line (-) OPLL. However, whether the anterior or posterior approach is preferable for this pathology has not been effectively determined.

MATERIALS AND METHODS

A total of 478 patients with myelopathy due to cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for two years. Of the 478 patients, 45 and 46 with K-line (-) underwent anterior and posterior fusion surgeries, respectively. After adjusting for confounders in baseline characteristics using a propensity score-matched analysis, 54 patients in both the anterior and posterior groups (27 patients each) were evaluated. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire.

RESULTS

Both approaches showed comparable neurological and functional recovery. The cervical range of motion was significantly restricted in the posterior group because of the large number of fused vertebrae compared with the anterior group. The incidence of surgical complications was comparable between the cohorts, but the posterior group demonstrated a higher frequency of segmental motor paralysis, whereas the anterior group more frequently reported postoperative dysphagia.

CONCLUSIONS

Clinical improvement was comparable between anterior and posterior fusion surgeries for patients with K-line (-) OPLL. The ideal surgical approach should be informed based on the balance between the surgeon's technical preference and the risk of complications.

Factors Associated with Loss of Cervical Lordosis after Laminoplasty for Patients with Cervical Ossification of the Posterior Longitudinal Ligament: Data from a Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

To investigate the incidence of loss of cervical lordosis after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). We also sought to determine associated risk factors and the relationship with patient-reported outcomes.

SUMMARY OF BACKGROUND DATA

Loss of cervical lordosis is a sequalae often observed after laminoplasty, which may adversely impact surgical outcomes. Cervical kyphosis, especially in OPLL, is associated with reoperation, but risk factors and relationship to postoperative outcomes remain understudied at this time.

METHODS

This study was conducted by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. We included 165 patients who underwent laminoplasty and completed Japanese Orthopaedic Association (JOA) score or Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaires (JOACMEQ), as well as visual analog scales (VAS) for pain, with imaging. The participants were divided into two groups: those with loss of cervical lordosis of>10° or 20° after surgery and those without loss of cervical lordosis. A paired t-test was applied to evaluate the association between changes in cervical spinal angles, ROM, and cervical JOA and VAS scores before and at 2 years postoperatively. Mann-Whitney U-test was used for JOACMEQ.

RESULTS

Postoperative loss of cervical lordosis>10° and>20° was observed in 32 (19.4%) and 7 (4.2%), respectively. JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small extension range of motion (eROM) was significantly associated with postoperative loss of cervical lordosis, and the cutoff values of eROM were 7.4° [area under the curve (AUC): 0.76] and 8.2° (AUC: 0.92) for loss of cervical lordosis>10° and>20°, respectively. A large occupation ratio of OPLL was also associated with loss of cervical lordosis, with a cutoff value of 39.9% (AUC: 0.94). Laminoplasty resulted in functional improvement in most patient-reported outcomes; however, neck pain and bladder function tended to become worse postoperatively in cases with postoperative loss of cervical lordosis>20°.

CONCLUSION

JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small eROM and large OPLL may represent factors associated with loss of cervical lordosis after laminoplasty in patients with OPLL.

Thoracic kyphosis in light of lumbosacral alignment in thoracic adolescent idiopathic scoliosis: recognition of thoracic hypokyphosis and therapeutic implications

BACKGROUND

The uniqueness of spinal sagittal alignment in thoracic adolescent idiopathic scoliosis (AIS), for example, the drastically smaller thoracic kyphosis seen in some patients, has been recognized but not yet fully understood. The purpose of this study was to clarify the characteristics of sagittal alignment of thoracic AIS and to determine the contributing factors.

METHODS

Whole spine radiographs of 83 thoracic AIS patients (73 females) were analyzed. The measured radiographic parameters were the Cobb angle of thoracic scoliosis, thoracic kyphosis (TK), lumbar lordosis (LL), C7 sagittal vertical axis (C7 SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Additionally, max-LL, which was defined as the maximum lordosis angle from the S1 endplate, the inflection point between thoracic kyphosis and lumbar lordosis, and the SVA of the inflection point (IP SVA) were measured. The factors significantly related to a decrease in TK were assessed by stepwise logistic regression analysis. In addition, cluster analysis was performed to classify the global sagittal alignment.

RESULTS

The significant factors for a decrease in TK were an increase in SS (p = 0.0003, [OR]: 1.16) and a decrease in max-LL (p = 0.0005, [OR]: 0.89). According to the cluster analysis, the global sagittal alignment was categorized into the following three types: Type 1 (low SS, low max-LL, n = 28); Type 2 (high SS, low max-LL, n = 22); and Type 3 (high SS, high max-LL, n = 33).

CONCLUSIONS

In thoracic AIS, a decreased TK corresponded to an increased SS or a decreased max-LL. The sagittal alignment of thoracic AIS patients could be classified into three types based on SS and max-LL. One of these three types includes the unique sagittal profile of very small TK.

Anterior instrumentation surgery for the treatment of Lenke type 1AR curve patterns

OBJECTIVE

Previous studies have demonstrated that Lenke lumbar modifier A contains 2 distinct types (AR and AL), and the AR curve pattern is likely to develop adding-on (i.e., a progressive increase in the number of vertebrae included within the primary curve distally after posterior surgery). However, the results of anterior surgery are unknown. The purpose of this study was to present the surgical results in a cohort of patients undergoing scoliosis treatment for type 1AR curves and to compare anterior and posterior surgeries to consider the ideal indications and advantages of anterior surgery for type 1AR curves.

METHODS

Patients with a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) and a minimum 2-year postoperative follow-up were included. The incidence of adding-on and radiographic data were compared between the anterior and posterior surgery groups. The numbers of levels between the end, stable, neutral, and last touching vertebra to the lower instrumented vertebra (LIV) were also evaluated.

RESULTS

Forty-four patients with a mean follow-up of 57 months were included. There were 14 patients in the anterior group and 30 patients in the posterior group. The main thoracic Cobb angle was not significantly different between the groups preoperatively and at final follow-up. At final follow-up, the anterior group had significantly less tilting of the LIV than the posterior group (-0.8° ± 4.5° vs 3° ± 4°). Distal adding-on was observed in no patient in the anterior group and in 6 patients in the posterior group at final follow-up (p = 0.025). In the anterior group, no LIV was set below the end vertebra, and all LIVs were set above last touching vertebra. The LIV was significantly more proximal in the anterior group than in the posterior surgery patients without adding-on for all reference vertebrae (p < 0.001).

CONCLUSIONS

This is the first study to investigate the surgical results of anterior surgery for Lenke type 1AR curve patterns, and it showed that anterior surgery for the curves could minimize the distal extent of the instrumented fusion without adding-on. This would leave more mobile disc space below the fusion.

Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial

IMPORTANCE

The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown.

OBJECTIVE

To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020.

INTERVENTIONS

Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment.

MAIN OUTCOMES AND MEASURES

The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury.

RESULTS

Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, -4.2 to 14.5; P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3]; P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%]; P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80; P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients).

CONCLUSIONS AND RELEVANCE

These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01485458; umin.ac.jp/ctr Identifier: UMIN000006780.

Randomized trial of granulocyte colony-stimulating factor for spinal cord injury

Attenuation of the secondary injury of spinal cord injury (SCI) can suppress the spread of spinal cord tissue damage, possibly resulting in spinal cord sparing that can improve functional prognoses. Granulocyte colony-stimulating factor (G-CSF) is a haematological cytokine commonly used to treat neutropenia. Previous reports have shown that G-CSF promotes functional recovery in rodent models of SCI. Based on preclinical results, we conducted early phase clinical trials, showing safety/feasibility and suggestive efficacy. These lines of evidence demonstrate that G-CSF might have therapeutic benefits for acute SCI in humans. To confirm this efficacy and to obtain strong evidence for pharmaceutical approval of G-CSF therapy for SCI, we conducted a phase 3 clinical trial designed as a prospective, randomized, double-blinded and placebo-controlled comparative trial. The current trial included cervical SCI [severity of American Spinal Injury Association (ASIA) Impairment Scale (AIS) B or C] within 48 h after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group was administered 400 μg/m²/day × 5 days of G-CSF in normal saline via intravenous infusion for five consecutive days. The placebo group was similarly administered a placebo. Allocation was concealed between blinded evaluators of efficacy/safety and those for laboratory data, as G-CSF markedly increases white blood cell counts that can reveal patient treatment. Efficacy and safety were evaluated by blinded observer. Our primary end point was changes in ASIA motor scores from baseline to 3 months after drug administration. Each group includes 44 patients (88 total patients). Our protocol was approved by the Pharmaceuticals and Medical Device Agency in Japan and this trial is funded by the Center for Clinical Trials, Japan Medical Association. There was no significant difference in the primary end point between the G-CSF and the placebo control groups. In contrast, one of the secondary end points showed that the ASIA motor score 6 months (P = 0.062) and 1 year (P = 0.073) after drug administration tend to be higher in the G-CSF group compared with the placebo control group. The present trial failed to show a significant effect of G-CSF in primary end point.

Can we use shorter constructs while maintaining satisfactory sagittal plane alignment for adult spinal deformity?

OBJECTIVE

Issues with spinopelvic fixation for adult spinal deformity (ASD) include loss of the physiological mobility of the entire lumbar spine, perioperative complications, and medical costs. Little is known about the factors associated with successful short fusion for ASD. The authors evaluated radiographic and clinical outcomes after shorter fusion for different subtypes of ASD at 2 years postoperatively and examined factors associated with successful short fusion.

METHODS

This was a single-center study of 37 patients who underwent short fusion and a minimum 2 years of follow-up for ASD in which lumbar kyphosis was the main deformity. The exclusion criteria were 1) age < 40 years, 2) previous lumbar vertebral fracture, 3) severe osteoporosis, 4) T10-L2 kyphosis > 20°, 5) scoliotic deformity with an upper end vertebra (UEV) above T12, and 6) concomitant Parkinson's disease or neurological disease. The surgical procedures, radiographic course, and Oswestry Disability Index (ODI) were assessed, and correlations between radiographic parameters and postoperative ODI at 2 years were analyzed.

RESULTS

A mean of 3.5 levels were fused. The mean radiographic parameters preoperatively, at 2 weeks, and at 2 years, respectively, were as follows: coronal Cobb angle: 22.9°, 11.5°, and 12.6°; lumbar lordosis (LL): 12.9°, 35.8°, and 32.2°; pelvic incidence (PI) minus LL: 35.5°, 14.7°, and 19.2°; pelvic tilt: 29.4°, 23.1°, and 25.0°; and sagittal vertical axis 85.3, 36.7, and 59.2 mm. Abnormal proximal junctional kyphosis occurred in 8 cases. Revision surgery was performed to extend the length of fusion from a lower thoracic vertebra to the pelvis in 2 cases. The mean ODI scores preoperatively and at 2 years were 50.7% and 24.1%, respectively. Patient age, number of fused intervertebral segments, and radiographic parameters were analyzed by the stepwise method to identify factors contributing to the ODI score at 2 years, preoperative PI, and sagittal vertical axis at 2 years. On receiver operating characteristic curve analysis of the minimal clinically important difference of ODI (15%) and preoperative PI, the cutoff value of the preoperative PI was 47° (area under the curve 0.75).

CONCLUSIONS

In terms of subtypes of ASD in which lumbar kyphosis is the main deformity, if the PI is < 47°, then the use of short fusion preserving mobile intervertebral segments can produce adequate LL for the PI, improving both postoperative global spinal alignment and quality of life.

Growing rod technique with prior foundation surgery and sublaminar taping for early-onset scoliosis

OBJECTIVE

The aim of this study was to show the surgical results of growing rod (GR) surgery with prior foundation surgery (PFS) and sublaminar taping at an apex vertebra.

METHODS

Twenty-two early-onset scoliosis (EOS) patients underwent dual GR surgery with PFS and sublaminar taping. PFS was performed prior to rod placement, including exposure of distal and proximal anchor areas and anchor instrumentation filled with a local bone graft. After a period of 3-5 months for the anchors to become solid, dual rods were placed for distraction. The apex vertebra was exposed and fastened to the concave side of the rods using sublaminar tape. Preoperative, post-GR placement, and final follow-up radiographic parameters were measured. Complications during the treatment period were evaluated using the patients' clinical records.

RESULTS

The median age at the initial surgery was 55.5 months (range 28-99 months), and the median follow-up duration was 69.5 months (range 25-98 months). The median scoliotic curves were 81.5° (range 39°-126°) preoperatively, 30.5° (range 11°-71°) after GR placement, and 33.5° (range 12°-87°) at the final follow-up. The median thoracic kyphotic curves were 45.5° (range 7°-136°) preoperatively, 32.5° (range 15°-99°) after GR placement, and 42° (range 11°-93°) at the final follow-up. The median T1-S1 lengths were 240.5 mm (range 188-305 mm) preoperatively, 286.5 mm (range 232-340 mm) after GR placement, and 337.5 mm (range 206-423 mm) at the final follow-up. Complications occurred in 6 patients (27%). Three patients had implant-related complications, 2 patients had alignment-related complications, and 1 patient had a wound-related complication.

CONCLUSIONS

A dual GR technique with PFS and sublaminar taping showed effective correction of scoliotic curves and a lower complication rate than previous reports when a conventional dual GR technique was used.

Pedicle screws with a thin hydroxyapatite coating for improving fixation at the bone-implant interface in the osteoporotic spine: experimental study in a porcine model

OBJECTIVE

Instrumentation failure caused by the loosening of pedicle screws (PSs) in patients with osteoporosis is a serious problem after spinal surgery. The addition of a thin hydroxyapatite (HA) surface coating applied by using a sputtering process was reported recently to be a promising method for providing bone conduction around an implant without a significant risk of coating-layer breakage. In this study, the authors evaluated the biomechanical and histological features of the bone-implant interface (BII) of PSs with a thin HA coating in an in vivo porcine osteoporotic spine model.

METHODS

Three types of PSs (untreated/standard [STPS], sandblasted [BLPS], and HA-coated [HAPS] PSs) were implanted into the thoracic and lumbar spine (T9–L6) of 8 mature Clawn miniature pigs (6 ovariectomized [osteoporosis group] and 2 sham-operated [control group] pigs). The spines were harvested from the osteoporosis group at 0, 2, 4, 8, 12, or 24 weeks after PS placement and from the control group at 0 or 24 weeks. Their bone mineral density (BMD) was measured by peripheral quantitative CT. Histological evaluation of the BIIs was conducted by performing bone volume/tissue volume and bone surface/implant surface measurements. The strength of the BII was evaluated with extraction torque testing.

RESULTS

The BMD decreased significantly in the osteoporosis group (p < 0.01). HAPSs exhibited the greatest mean extraction peak torque at 8 weeks, and HAPSs and BLPSs exhibited significantly greater mean torque than the STPSs at 12 weeks (p < 0.05). The bone surface/implant surface ratio was significantly higher for HAPSs than for STPSs after 2 weeks (p < 0.05), and bonding between bone and the implant surface was maintained until 24 weeks with no detachment of the coating layer. In contrast, the bone volume/tissue volume ratio was significantly higher for HAPSs than for BLPSs or STPSs only at 4 weeks.

CONCLUSIONS

Using PSs with a thin HA coating applied using a sputtering process strengthens bonding at the BII, which might improve early implant fixation after spinal surgery for osteoporosis. However, the absence of increased bone mass around the screw remains a concern; prescribing osteoporosis treatment to improve bone quality might be necessary to prevent fractures around the screws.

Study protocol for the G-SPIRIT trial: a randomised, placebo-controlled, double-blinded phase III trial of granulocyte colony-stimulating factor-mediated neuroprotection for acute spinal cord injury

INTRODUCTION

Granulocyte colony-stimulating factor (G-CSF) is generally used for neutropaenia. Previous experimental studies revealed that G-CSF promoted neurological recovery after spinal cord injury (SCI). Next, we moved to early phase of clinical trials. In a phase I/IIa trial, no adverse events were observed. Next, we conducted a non-randomised, non-blinded, comparative trial, which suggested the efficacy of G-CSF for promoting neurological recovery. Based on those results, we are now performing a phase III trial.

METHODS AND ANALYSIS

The objective of this study is to evaluate the efficacy of G-CSF for acute SCI. The study design is a prospective, multicentre, randomised, double-blinded, placebo-controlled comparative study. The current trial includes cervical SCI (severity of American Spinal Injury Association (ASIA) Impairment Scale B/C) within 48 hours after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group is administered 400 µg/m²/day×5 days of G-CSF in normal saline via intravenous infusion for 5 consecutive days. The placebo group is similarly administered a placebo. Our primary endpoint is changes in ASIA motor scores from baseline to 3 months. Each group includes 44 patients (88 total patients).

ETHICS AND DISSEMINATION

The study will be conducted according to the principles of the World Medical Association Declaration of Helsinki and in accordance with the Japanese Medical Research Involving Human Subjects Act and other guidelines, regulations and Acts. Results of the clinical study will be submitted to the head of the respective clinical study site as a report after conclusion of the clinical study by the sponsor-investigator. Even if the results are not favourable despite conducting the clinical study properly, the data will be published as a paper.

TRIAL REGISTRATION NUMBER

UMIN000018752.

Multiple concave rib head resection improved correction rate of posterior spine fusion in treatment of adolescent idiopathic scoliosis

BACKGROUND

Hybrid constructs have been widely used to surgically correct thoracic adolescent idiopathic scoliosis (AIS). To enhance the correction obtained with hybrid constructs, we perform concave rib head resection and convex costovertebral release as posterior release procedures. The objective of the study was to evaluate coronal and sagittal curve correction in patients with adolescent idiopathic scoliosis (AIS) treated with hybrid constructs combined with concave rib head resection and convex transverse process resection as posterior release procedures.

METHODS

The records of 24 patients with Lenke type 1 or 2 AIS treated with hybrid constructs combined with posterior release procedures were retrospectively reviewed. The mean age at surgery was 14.3 years. The mean follow-up period was 33.0 months (range, 24-60 months). Radiographs were evaluated before surgery, immediately postoperatively, and at latest follow-up.

RESULTS

The average preoperative Cobb angle of the main thoracic (MT) curve was 58.1 ± 12.6° (range, 45-88°). The MT curve was corrected to 12.8 ± 9.0° (range, 0-38°) immediately after surgery. At the latest follow-up, the average Cobb angle was 13.6 ± 9.9° (range, 0-44°; correction, 77.5 ± 14.0%). The average loss of coronal correction was 0.8°. The average preoperative flexibility of the MT curve was 54.6 ± 17.4%. The average Cincinnati correction index was 1.53 ± 0.48 at the latest follow-up. The average preoperative thoracic kyphosis (TK) was 13.7 ± 12.0° (range, -12-34°). Immediately after surgery, TK was corrected to 18.6 ± 5.9° (range, 10-29°). At the latest follow-up, TK measured 18.1 ± 6.5° (range, 6-32°).

CONCLUSIONS

Hybrid instrumentation combined with concave rib head resection and convex transverse process resection as posterior release procedures achieved satisfactory coronal and sagittal curve correction with little loss of correction at 2-year follow-up.

Comparative study of radiographic disc height changes using two different interbody devices for transforaminal lumbar interbody fusion: open box vs. fenestrated tube interbody cage

STUDY DESIGN

Retrospective comparative study of the postoperative subsidence of two interbody devices following posterior or transforaminal lumbar interbody fusion (PLIF/TLIF) for degenerative spondylolisthesis of the lumbar spine.

OBJECTIVE

To assess certain radiograph characteristics of PLIF/TLIF using two interbody fusion devices at L4-L5.

SUMMARY OF BACKGROUND DATA

PLIF can achieve spinal stabilization with vertebral body support and direct neural decompression. Although various interbody devices have been used in PLIF procedures, no radiographic studies have compared the load-bearing capabilities of open box and fenestrated tube interbody cages.

METHODS

Seventy-five patients who underwent one-level PLIF in the L4-L5 [corrected] segment for degenerative spondylolisthesis were retrospectively reviewed with a minimum 2-year follow-up. Fenestrated tube (Group FT: n = 30 [corrected]) or open box (Group OB: n = 45 [corrected]) cages were used for the PLIF procedure. The following radiographic parameters were evaluated to compare the load-bearing capabilities: disc space height (DH); percent increase and decrease of disc height (% IDH and % DDH, respectively); and percent coverage of the cage on the endplate (% CC).

RESULTS

There were no significant differences in the baseline data, including age, segmental instability and osteoporotic status, between the two groups. Anterior %IDH and % CC were significantly higher in Group OB than in Group FT (% IDH: 69.4% vs. 57.3%; % OC: 24.5% vs. 12.9%), and anterior and posterior % DDH were significantly higher in Group FT than in Group OB (anterior: -2.9% vs. -.1%; posterior: -6.6% vs. -.3%). Although the restored DH gradually reduced over time in both groups, significant reduction to the preoperative level only occurred in Group FT.

CONCLUSIONS

The load-bearing capabilities of the open box cage are superior to those of the fenestrated tube cage. Since there were no significant differences between the baseline status of the two groups, the larger cross-sectional area and stable framework design of the open box cage appears to bring about a greater load-bearing capability. Therefore, the open box cage seems to be biomechanically more advantageous as an interbody device for PLIF than the fenestrated tube cage.

Unilateral transforaminal lumbar interbody fusion and bilateral anterior-column fixation with two Brantigan I/F cages per level: clinical outcomes during a minimum 2-year follow-up period

OBJECT

There are no published reports of unilateral transforaminal lumbar interbody fusion (TLIF) in which two Brantigan I/F cages were placed per level through a single portal to achieve bilateral anterior-column support. The authors describe such a surgical technique and evaluate the clinical outcomes of this procedure.

METHODS

Data obtained in 86 (93.5%) of the first 92 consecutive patients who underwent the procedure were retrospectively reviewed; the minimum follow-up duration was 2 years. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scoring system. Disc height, disc angle, cage positioning in the axial plane, and fusion status were radiographically evaluated. The mean follow-up period was 33.8 months. The mean improvement in the JOA score was 77.2%. Fusion was successful in 93% of the cases. According to the Farfan method, the mean anterior and posterior disc heights increased from 20.2 and 16.9% preoperatively to 35.9 and 22.7% at follow up, respectively (p < 0.01). The mean disc angle increased from 4.8degrees preoperatively to 7.5degrees at last follow-up examination (p < 0.01). Two cages were correctly placed to achieve bilateral anterior-column support in greater than 85% of the cases. The following complications occurred: hardware migration in two patients and deep infection cured by intravenous antibiotic therapy in one patient.

CONCLUSIONS

Unilateral TLIF involving the placement of two Brantigan cages per level led to good clinical results. Two Brantigan cages were adequately placed via a single portal, and reliable bilateral anterior-column support was achieved. Although the less invasive unilateral approach was used, the outcomes were as good as those in many reported series of posterior lumbar interbody fusion in which the Brantigan cages were placed via the bilateral approach.

Iliac crest reconstruction with a bioactive ceramic spacer

This study aimed to investigate the long-term clinical results of the apatite wollastonite-containing glass ceramic (AWGC) iliac spacer and to discuss its efficacy in reconstruction of the bone graft donor site at the iliac crest. Thirty-one patients were studied for more than 10 years. All patients underwent anterior spinal fusion using autogenous tricortical iliac bone graft. After harvest of tricortical iliac bone graft, an AWGC iliac spacer ranging from 15 mm to 70 mm in length was press-fitted into the gap. Long-term clinical results were obtained from radiological and blood examinations. Thirty patients (97%) were satisfied with the spacer. There was new bone formation around the spacer on the radiograph. There was no abnormal silicon concentration in blood examinations. AWGC iliac spacer appears to be useful in the reconstruction of harvested iliac crest. New bone formation occurs, reducing the defect size.

[Studies on treatment of invasive mole and subsequent reproductive performance, a report of 39 cases (author's transl)]

Thirty-nine invasive mole patients treated during the last 6 years (1971-1976) in our clinic, were studied. The data were summarized in the following items. 1. Surgical treatment was done in 31 cases (79.5%), and methods of operation were removal of focus in 13 cases and hysterectomy in 18. Chemotherapy was performed in 31 cases (79.5%). 2. In 31 operated patients, all of invasive lesions were in uterine bodies. A degree of chorial invasion into myometrium was shallow in 12 cases, medium in 12 and deep in 7. Molar vesicles were observed in 17 cases and trophoblastic tissues were microscopically confirmed in 14. 3. Anti-cancer agents, such as ACTD and MTX, were required 1-4 courses in 8 patients received chemotherapy alone and 1-6 courses in 23 patients received operation combined with chemotherapy. 4. Up to the present time, 14 pregnancies in 11 cases out of these patients occurred, but 2 of them ended in spontaneous abortion and one was molar pregnancy. 5. Malignant sequela, that is, choriocarcinoma was occurred in 2 cases. But, these 2 cases are in remission. 6. Thirty-seven patients, including 2 choriocarcinoma cases, are healthy at present.