Insufficient Recovery From C5 Palsy Following Anterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine the risk factors for insufficient recovery from C5 palsy (C5P) following anterior cervical decompression and fusion (ADF). SUMMARY OF BACKGROUND DATA: Postoperative C5P is a frequent but unsolved complication following cervical decompression surgery. Although most patients gradually recover, some recover only partially. When we encounter new-onset C5P following ADF, the question that often arises is whether the palsy will sufficiently resolve. METHODS: We retrospectively reviewed consecutive patients who underwent ADF at our institution. We defined C5P as postoperative deterioration of deltoid muscle strength by two or more grades determined by manual muscle testing (MMT). We evaluated the following demographic data: patient factors, surgical factors, and radiological findings. C5P patients were divided into two groups: sufficient recovery (MMT grade≧4) and insufficient recovery (MMT grade < 4). Each parameter was compared between the two groups. RESULTS: Of 839 patients initially included in the study, 57 experienced new-onset C5P (6.8%). At the final follow-up (mean, 55 ±â€Š17 months), 41 patients experienced sufficient recovery, whereas 16 (28%) still exhibited insufficient recovery. Compared with the sufficient recovery group, patients with insufficient recovery exhibited a higher decompression combination score, a larger anterior shift in preoperative cervical sagittal balance, less lordosis of the pre- and postoperative C4/C5 segment, more frequent stenosis at the C3/C4 segment, lower deltoid strength at C5P onset, more frequent co-occurrence of biceps weakness, greater postoperative expansion of the dura mater, and more frequent presence of postoperative T2 high-intensity areas. Multivariate analysis revealed that co-occurrence of biceps muscle weakness, less lordosis at the preoperative C4/C5 segment, and postoperative expansion of the dura mater were independent predictors of insufficient recovery. CONCLUSION: The combination of unfavorable conditions, such as potential spinal cord disorder, cervical malalignment, and excessive expansion of the dura mater after corpectomy, predicts insufficient recovery from C5P.Level of Evidence: 4.

HE4 Predicts Progressive Fibrosis and Cardiovascular Events in Patients With Dilated Cardiomyopathy.

Background Cardiac fibrosis plays a crucial role in the pathogenesis of dilated cardiomyopathy (DCM). HE4 (human epididymis protein 4) is a secretory protein expressed in activated fibroblasts that exacerbates tissue fibrosis. In the present study, we investigated the clinical utility of HE4 measurement in patients with DCM and its pathophysiological role in preclinical experiments in vivo and in vitro. Methods and Results We measured serum HE4 levels of 87 patients with DCM. Endomyocardial biopsy expressed severe fibrosis only in the high HE4 group (P<0.0001). Echocardiography showed that left ventricular end-diastolic diameter tends to decrease over time (58±7.3 to 51±6.6 mm; P<0.0001) in the low HE4 group (<59.65 pmol/L [median value]). HE4 was significantly associated with risk reduction of mortality and cardiovascular hospitalization in multivariate Cox model. In vivo, HE4 was highly expressed in kidney and lung tissue of mouse, and scarcely expressed in heart. In genetically induced DCM mouse model, HE4 expression increased in kidney but not in heart and lung. In vitro, supernatant from HE4-transfected human embryonic kidney 293T cells enhanced transdifferentiation of rat neonatal fibroblasts and increased expression of fibrosis-related genes, and this was accompanied by the activation of extracellular signal-regulated kinase signaling in cardiac fibroblasts. Treatment with an inhibitor of upstream signal of extracellular signal-regulated kinase or a neutralizing HE4 antibody canceled the profibrotic properties of HE4. Conclusions HE4 functions as a secretory factor, activating cardiac fibroblasts, thereby inducing cardiac interstitial fibrosis. HE4 could be a promising biomarker for assessing ongoing fibrosis and a novel therapeutic target in DCM. Registration URL: https://upload.umin.ac.jp/cgi-open-bin/ctr; Unique identifier: UMIN000043062.

Association Between C5 Palsy and the Anterior Decompression Procedures, Corpectomy and Discectomy.

STUDY DESIGN: This is a retrospective study. OBJECTIVE: The aim was to evaluate the influence of various decompression procedures on the incidence of C5 palsy (C5P). SUMMARY OF BACKGROUND DATA: C5P is a well-known but unsolved complication of cervical spine surgery. Among anterior cervical decompressive procedures, both corpectomy and discectomy are important surgical methods, whose effects on the incidence of C5P are unknown. METHODS: We retrospectively analyzed 818 patients (529 men; mean age: 59.2±11.6 y) who underwent anterior cervical decompression and fusion. The surgical choice to use corpectomy, discectomy, or hybrid decompression was based on standard treatment strategies depending on local compressive pathology and presenting clinical symptoms. We introduced an original "decompression combination score" as a means of quantifying the effects of the procedures on the development of C5P. The scores were based on the relative severity of various risk factors associated with the eventual development of C5P and were assigned as follows: C4 corpectomy, 1 point; C5 corpectomy, 1 point; C3 corpectomy successive to C4 corpectomy, 0.5 point; C6 or C7 corpectomy successive to C5 corpectomy, 0.5 point; C4/5 discectomy, 0.5 point; discectomy at another segment, 0 point. Each patient's decompression combination score was then comprised of the sum of these points. RESULTS: C5P occurred in 55 (47 men, mean age: 65.7±8.7 y) of the 818 (6.7%) patients. A larger number of operated disc segments was significantly associated with C5P. Higher decompression combination score was significantly associated with C5P. Multivariate analysis revealed that male sex, higher decompression combination score, and older age were significant risk factors. CONCLUSIONS: Corpectomy increased the incidence of C5P, while discectomy decreased the risk. The lower incidence of postoperative C5P after discectomy may be because of minimizing tethering effect to the C5 nerve root. As a preventive measure against C5P, corpectomy should be avoided, while discectomy is recommended as much as possible. LEVEL OF EVIDENCE: Levels of Evidence: Step IV-Oxford Center for Evidence-Based Medicine 2011.

Sirt7 Deficiency Attenuates Neointimal Formation Following Vascular Injury by Modulating Vascular Smooth Muscle Cell Proliferation.

BACKGROUND: Sirt7 is a recently identified sirtuin and has important roles in various pathological conditions, including cancer progression and metabolic disorders. It has previously been reported that Sirt7 is a key molecule in acute myocardial wound healing and pressure overload-induced cardiac hypertrophy. In this study, the role of Sirt7 in neointimal formation after vascular injury is investigated.Methods and Results:Systemic (Sirt7-/-) and smooth muscle cell-specific Sirt7-deficient mice were subjected to femoral artery wire injury. Primary vascular smooth muscle cells (VSMCs) were isolated from the aorta of wild type (WT) and Sirt7-/-mice and their capacity for cell proliferation and migration was compared. Sirt7 expression was increased in vascular tissue at the sites of injury. Sirt7-/-mice demonstrated significant reduction in neointimal formation compared to WT mice. In vitro, Sirt7 deficiency attenuated the proliferation of serum-induced VSMCs. Serum stimulation-induced upregulation of cyclins and cyclin-dependent-kinase 2 (CDK2) was significantly attenuated in VSMCs of Sirt7-/-compared with WT mice. These changes were accompanied by enhanced expression of the microRNA 290-295 cluster, the translational negative regulator of CDK2, in VSMCs of Sirt7-/-mice. It was confirmed that smooth muscle cell-specific Sirt7-deficient mice showed significant reduction in neointima compared with control mice. CONCLUSIONS: Sirt7 deficiency attenuates neointimal formation after vascular injury. Given the predominant role in vascular neointimal formation, Sirt7 is a potentially suitable target for treatment of vascular diseases.

Cardiomyocyte Sirt (Sirtuin) 7 Ameliorates Stress-Induced Cardiac Hypertrophy by Interacting With and Deacetylating GATA4.

Sirt (Sirtuin) 7, the most recently identified mammalian sirtuin, has been shown to contribute to appropriate wound healing processes after acute cardiovascular insult. However, its role in the development of cardiac remodeling after pressure overload is unclear. Cardiomyocyte-specific Sirt7-knockout and control mice were subjected to pressure overload induced by transverse aortic constriction. Cardiac hypertrophy and functions were then examined in these mice. Sirt7 protein expression was increased in myocardial tissue after pressure overload. Transverse aortic constriction-induced increases in heart weight/tibial length were significantly augmented in cardiomyocyte-specific Sirt7-knockout mice compared with those of control mice. Histological analysis showed that the cardiomyocyte cross-sectional area and fibrosis area were significantly larger in cardiomyocyte-specific Sirt7-deficient mice. Cardiac contractile functions were markedly decreased in cardiomyocyte-specific Sirt7-deficient mice. Mechanistically, we found that Sirt7 interacted directly with GATA4 and that the exacerbation of phenylephrine-induced cardiac hypertrophy by Sirt7 knockdown was decreased by GATA4 knockdown. Sirt7 deacetylated GATA4 in cardiomyocytes and regulated its transcriptional activity. Interestingly, we demonstrated that treatment with nicotinamide mononucleotide, a known key NAD+ intermediate, ameliorated agonist-induced cardiac hypertrophies in a Sirt7-dependent manner in vitro. Sirt7 deficiency in cardiomyocytes promotes cardiomyocyte hypertrophy in response to pressure overload. Sirt7 exerts its antihypertrophic effect by interacting with and promoting deacetylation of GATA4.

Surgical strategies and outcomes for intradural lipomas over the past 20 years.

Intradural lipoma is an extremely rare spinal tumor. The boundary between the spinal cord and the lipoma is usually unclear, with adhesions being firm. Thus, total resection of the tumor is difficult and the neurological prognosis after total resection is poor. Information on the management of this type of tumor is scarce owing to the limited studies that have been conducted and the low sample sizes reported. Here, we report a case and provide a review of the literature on intradural lipomas over the past 20 years. In addition to describing our case, we reviewed reports published in Pubmed and CiNii. The demographic data of the patients included in these studies were extracted and the surgical procedures were assessed, along with their corresponding postoperative outcomes. There were 57 primary cases and 4 cases of recurrence. Among the primary cases, the neurological symptoms were persistent in 54 (95%) after surgery. The postoperative outcomes after excessive (>60% tumor resection) or total resection were significantly poor. In the recurrence cases, the mean period from initial surgery to recurrence was 11 years and all initial surgical procedures involved only partial resection surgery. This report is, to the best of our knowledge, the most exhaustive analysis of cases of intradural lipomas and recurrences. The optimal treatment for lipoma necessitates both partial resection and duraplasty.

Akt1-Mediated Muscle Growth Promotes Blood Flow Recovery After Hindlimb Ischemia by Enhancing Heme Oxygenase-1 in Neighboring Cells.

BACKGROUND: Resistance exercise has beneficial effects for patients with peripheral arterial diseases. The hypothesis that muscle growth promotes angiogenesis by interacting with neighboring cells in ischemic lesions was assessed. Methods and Results: Skeletal muscle-specific inducible Akt1 transgenic (Akt1-TG) mice that induce growth of functional skeletal muscles as a model of resistance training were used. Proteomics analysis identified significant upregulation of heme oxigenase-1 (HO-1) in muscle tissue in Akt1-TG mice compared with control mice. Blood flow recovery after hindlimb ischemia was significantly increased in Akt1-TG mice compared with control mice. Enhanced blood flow and capillary density in Akt1-TG mice were completely abolished by the HO-1 inhibitor, Tin-mesoporphyrin. Immunohistochemistry showed that HO-1 expression was not increased in muscle cells, but it was increased in macrophages and endothelial cells. Consistent with these findings, blood flow recovery after hindlimb ischemia was similar between control mice and skeletal muscle-specific HO-1-knockout mice. Adenoviral-mediated overexpression of Akt1 did not increase HO-1 protein expression in C2C12 myotubes; however, the conditioned medium from Akt1-overexpressing C2C12 myotubes increased HO-1 expression in endothelial cells. Cytokine array demonstrated that a panel of cytokine secretion was upregulated in Akt1-overexpressing C2C12 cells, suggesting paracrine interaction between muscle cells and endothelial cells and macrophages. CONCLUSIONS: Akt1-mediated muscle growth improves blood flow recovery after hindlimb ischemia by enhancing HO-1 expression in neighboring cells.

Non-invasive testing for sarcopenia predicts future cardiovascular events in patients with chronic kidney disease.

BACKGROUND: Sarcopenia is frequently observed and associated with poor outcomes in patients with chronic kidney disease (CKD). A simple screening test for sarcopenia using age, grip strength, and calf circumference was recently developed. However, the clinical utility of this sarcopenia score in patients with CKD remains unclear. METHODS AND RESULTS: We calculated the sarcopenia score of 265 patients with CKD and followed the patients for cardiovascular events. The endpoint of this study was the composite of cardiovascular hospitalization and total mortality. We divided all participants into high (n = 166) and low (n = 99) sarcopenia score groups using a simple scoring system. Patients in the high sarcopenia score group showed significantly higher plasma B-type natriuretic peptide (BNP) levels than those in the low sarcopenia score group (median: 103.1, interquartile range: 46.3-310.0 vs. 46.7, 18.0-91.8 pg/mL; p < 0.0001). The Kaplan-Meier curve revealed that the risk of cardiovascular events was significantly greater in the high sarcopenia score group (log-rank test: p < 0.0001), even after potential confounding factors were corrected using propensity score matching. Multivariate Cox hazard analysis identified a high sarcopenia score (hazard ratio: 3.04, 95% confidence interval: 1.45-6.38, p = 0.003) as an independent predictor of the primary endpoints. Furthermore, the combination of a high sarcopenia score and high BNP level identified patients with a significantly higher probability of future events (p < 0.0001). CONCLUSIONS: This study demonstrates that this simple screening score for sarcopenia could be a useful tool for estimating the future adverse event risk in patients with CKD.

Surgical results and complications of anterior decompression and fusion as a revision surgery after initial posterior surgery for cervical myelopathy due to ossification of the posterior longitudinal ligament.

OBJECTIVE Ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. An anterior cervical decompression and fusion (ACDF) procedure for cervical OPLL is theoretically feasible, as the lesion exists anteriorly; however, such a procedure is considered technically demanding and is associated with serious complications. Cervical laminoplasty is reportedly an effective alternative procedure with few complications; it is recognized as a comparatively safe procedure, and has been widely used as an initial surgery for cervical OPLL. After posterior surgery, some patients require revision surgery because of late neurological deterioration due to kyphotic changes in cervical alignment or OPLL progression. Here, the authors retrospectively investigated the surgical results and complications of revision ACDF after initial posterior surgery for OPLL. METHODS This was a single-center, retrospective study. Between 2006 and 2013, 19 consecutive patients with cervical OPLL who underwent revision ACDF at the authors' institution after initial posterior surgery were evaluated. The mean age at the time of revision ACDF was 66 ± 7 years (± SD; range 53-78 years). The mean interval between initial posterior surgery and revision ACDF was 63 ± 53 months (range 3-235 months). RESULTS The mean follow-up period after revision ACDF was 41 ± 26 months (range 24-108 months). Before revision ACDF, the mean maximum thickness of the ossified posterior longitudinal ligament was 7.2 ± 1.5 mm (range 5-10 mm), and the mean C2-7 angle was 1.3° ± 14° (range -40° to 24°). The K-line was plus (OPLL did not exceed the K-line) in 8 patients and minus in 11 (OPLL exceeded the K-line). The mean Japanese Orthopaedic Association score improved from 10 ± 3 (range 3-15) before revision ACDF to 11 ± 4 (range 4-15) at the last follow-up, and the mean improvement rate was 18% ± 18% (range 0%-60%). A total of 16 surgery-related complications developed in 12 patients (63%). The main complication was an intraoperative CSF leak in 8 patients (42%). Neurological function worsened in 5 patients (26%). The deterioration was due to spinal cord herniation through a defective dura mater in 1 patient, unidentified in 1 patient, and C-5 palsy that gradually recovered in 3 patients. Reintubation, delirium, and hoarseness were observed in 1 patient each (5%). No patient required reoperation for reconstruction failure, and all patients eventually had a solid bony fusion. CONCLUSIONS ACDF as revision surgery after initial posterior surgery for cervical myelopathy due to OPLL is associated with a high incidence of intraoperative CSF leakage and an extremely low improvement rate. The authors think that while the use of revision ACDF must be limited, it is indispensable in special cases, such as progressing myelopathy following posterior surgery due to a very large beak-type OPLL that exceeds the K-line. Postoperative OPLL progression and/or kyphotic changes can possibly cause later neurological deterioration. Fusion should be recommended at the initial surgery for many cases of cervical OPLL to prevent such a challenging revision surgery.

Reduced trans-mitral A-wave velocity predicts the presence of wild-type transthyretin amyloidosis in elderly patients with left ventricular hypertrophy.

Wild-type transthyretin amyloidosis (ATTRwt) is often overlooked in elderly patients with left ventricular hypertrophy (LVH). Impaired atrial function, in addition to ventricular diastolic dysfunction, is one of the hallmarks of cardiac amyloidosis. Here, we assessed the hypothesis that atrial function evaluated by A-velocity in pulse Doppler echocardiography is useful to differentiate ATTRwt in elderly patients with LVH. We analyzed 133 consecutive patients who underwent tissue biopsy to rule out infiltrative cardiomyopathy in our institute. We excluded patients younger than 50 years, without LVH (LV thickness was less than 12 mm), with other types of cardiac amyloidosis and patients with chronic atrial fibrillation, and analyzed remaining 51 patients (ATTRwt: 16, non-ATTRwt: 35). ATTRwt patients were significantly older and had advanced heart failure compared with non-ATTRwt group. In echocardiography, E/A, E/e', and relative wall thickness was significantly higher in ATTRwt group than non-ATTRwt group. A-velocity was significantly decreased in ATTRWT group compared with non-ATTRwt group (40.8 ± 20.8 vs. 78.7 ± 28.2 cm/s, p = 0.0001). Multivariate logistic analysis using eight forced inclusion models identified trans-mitral Doppler A-wave velocity was more significant factor of cardiac amyloidosis in ATTRwt. In receiver operating characteristic (ROC) analysis, the area under the curve (AUC) for A-wave velocity in discrimination between ATTRwt and non-ATTRwt were 0.86 (CI 0.76-0.96, p < 0.001). The cut-off value was 62.5 cm/s, and it yielded the best combination of sensitivity (69.7%) and specificity (87.5%) for prediction of amyloidosis. We concluded that reduced A-velocity predicts the presence of ATTRwt in elderly patients with LVH in sinus rhythm.

Optical coherence tomography visualization of stent deformation with subsequent thrombus adhesion at very early phase after everolimus-eluting stent implantation: a case report.

BACKGROUND: Stent malapposition, stent fracture, and deformity, and inadequate anti-thrombotic therapy are known as the risk of stent thrombosis. We report a case of stent deformation with subsequent thrombus adhesion at the site of a partial stent fracture detected by intravascular ultrasound (IVUS) and optical coherence tomography (OCT). CASE PRESENTATION: A 61-year-old male patient was diagnosed as effort angina pectoris. Coronary angiography revealed obstructions in the proximal segment of the left anterior descending (LAD) and left circumflex artery (LCx). Elective percutaneous coronary intervention (PCI) was scheduled for these lesions in the prior hospital. First, an everolimus-eluting stent (EES) was implanted in the just proximal LAD slightly protruding into left main trunk. One week later, the treatment to residual obstruction at proximal LCx was attempted. During delivery of the stent to LCx, the proximal edge of the previously-implanted LAD stent got stuck with the newly-deploying stent and deformed into the intravascular lumen when retracting the stent into the guide-catheter. He was immediately transferred to our hospital to repair these procedural problems. Two days later after the index procedure to LCx, intracoronary imaging with an IVUS and OCT were performed, and the IVUS/OCT imaging revealed thrombus adhesion around the deformed struts. The three-dimensional OCT guide also helped the detection of the deformed stent and the repair of deformed struts by additional stenting and kissing balloon technique. CONCLUSION: The current case suggested that thrombus adhesion can occur at the site of deformed and/or fractured stent at very early phase after stent implantation.

A simple sarcopenia screening test predicts future adverse events in patients with heart failure.

BACKGROUND: Progressive loss of skeletal muscle termed "sarcopenia" is an independent risk factor for mortality in patients with cardiovascular diseases. A simple screening test that can identify sarcopenia using three variables (age, grip strength and calf circumference) was recently developed. We evaluated the clinical utility of this screening test in patients with heart failure (HF). METHODS AND RESULTS: HF patients were divided into the sarcopenia (n=82) and non-sarcopenia (n=37) groups based on the sarcopenia score. Circulating BNP and high-sensitive cardiac troponin T levels were significantly higher, and left ventricular ejection fraction was lower in the sarcopenia group than non-sarcopenia group. Kaplan-Meier curve showed that HF event-free survival rate was significantly lower in the sarcopenia group. Multivariate Cox proportional hazards analysis identified BNP (ln[BNP]) (hazard ratio [HR]: 1.58; 95% CI: 1.09-2.29, p=0.02), hs-CRP (ln[CRP]) (HR: 1.82; 95% CI: 1.23-2.68; p<0.01) and sarcopenia score (HR: 1.03; 95% CI: 1.01-1.05, p<0.01) as independent predictors of HF events. In receiver operating characteristic analysis, adding the sarcopenia score to BNP levels increased an area under the curve for future HF events (sarcopenia score alone, 0.77; BNP alone, 0.82; combination, 0.89). CONCLUSIONS: The sarcopenia screening test can be used to predict future adverse events in patients with HF.

Extremely wide and asymmetric anterior decompression causes postoperative C5 palsy: an analysis of 32 patients with postoperative C5 palsy after anterior cervical decompression and fusion.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: We examined whether extremely wide and asymmetric anterior decompression causes postoperative C5 palsy. SUMMARY OF BACKGROUND DATA: Postoperative C5 palsy is a complication of cervical decompression surgery. We hypothesized that C5 palsy may be caused by nerve root impairment through extremely wide and asymmetric dural expansion due to unilateral predominant wide anterior decompression with concomitant C4-C5 foraminal stenosis. METHODS: The study included 32 patients with postoperative C5 palsy from a cohort of 459 patients who underwent anterior cervical decompression and fusion at the C4-C5 disc level for cervical myelopathy. The 64 upper extremities were divided into 2 groups according to palsy side (n = 35) or nonpalsy side (n = 29). Also, to correlate radiological findings, 66 consecutive patients who underwent anterior cervical decompression and fusion without postoperative C5 palsy were selected as control. RESULTS: In patients with C5 palsy, the unilateral decompression width on the palsy side was significantly larger than that on the nonpalsy side (8.63 vs. 6.92 mm, P = 0.0003). In addition, the decompression width was significantly larger (15.69 vs. 14.38 mm, P = 0.02), the diameter of the C4-C5 foramen was significantly smaller (2.73 vs. 3.24 mm, P = 0.0008), the anterior spinal cord shift was significantly smaller (0.14 vs. 0.73 mm, P< 0.0001), and significant decompression asymmetry (0.74 vs. 0.89, P = 0.0003) was present in the patients with C5 palsy compared with controls. CONCLUSION: Extremely wide and asymmetric decompression concomitant with pre-existing C4-C5 foraminal stenosis may cause postoperative C5 palsy. Our findings should be valuable for surgeons considering anterior cervical decompression and fusion that includes the C4-C5 level. Surgeons should consider restriction of the decompression width to less than 15 mm and avoiding asymmetric decompression to reduce the incidence of C5 palsy.

Risk factors for cage retropulsion after posterior lumbar interbody fusion: analysis of 1070 cases.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: We examined the risk factors for cage retropulsion after posterior lumbar interbody fusion (PLIF) performed for patients with degenerative lumbar spinal diseases. SUMMARY OF BACKGROUND DATA: Although PLIF is a widely accepted procedure, problems remain regarding perioperative and postoperative complications. There are few reported studies identifying specific risk factors for cage retropulsion, one of the implant-related complications after PLIF, although several case reports have been published. METHODS: Between April 2006 and July 2010, 1070 patients with various degenerative lumbar spinal diseases underwent single- or multilevel PLIF combined with posterolateral fusion, using posterior pedicle screw fixation and box-type cages. Their medical records and preoperative radiographs were reviewed and the factors influencing the incidence of cage retropulsion were analyzed. RESULTS: There were 9 cases of cage retropulsion (7 men and 2 women; mean age, 68.2 yr), and it developed within 2 months after surgery in all cases. Five patients had low back pain or leg pain, 3 of whom required revision surgery. The mean fusion level was 3.9 (range, 2-5); in 6 of the 9 patients, the cage had migrated at L5/S, 2 at L4/5, and 1 at L3/4. All of the cages were inserted at the end disc level of multilevel fusion procedures. The disc heights and ranges of motion were significantly greater in patients with cage retropulsion, and patients with a pear-shaped disc space also showed a higher rate of cage retropulsion. CONCLUSION: These results indicate that PLIF at L5/S, a wide disc space with instability, multilevel fusion surgery, and a pear-shaped disc space on lateral radiographs are risk factors for cage retropulsion. The identification of these risk factors should allow us to avoid this complication, and the use of expandable cages is an effective option for such cases.

Anterior corpectomy with fusion in combination with an anterior cervical plate in the management of ossification of the posterior longitudinal ligament.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study is to evaluate the safety and efficacy of an anterior cervical plate (ACP) used in combination with anterior corpectomy with fusion (ACF) for cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Consensus is lacking about the most suitable method to treat cervical myelopathy caused by OPLL. The decision to perform an ACF to treat multilevel myelopathy is controversial because of the potential for problems in the grafted bone. METHODS: We evaluated the surgical outcome of ACF combined with insertion of an ACP for treating cervical myelopathy caused by OPLL. The study group comprised 68 patients who were treated from 2006 to 2009 and followed for an average of 29.6 months. We retrospectively reviewed the information in the patients' charts and radiographs. RESULTS: No dislodgement of the grafted bone or implant was observed, and no patient developed infection, esophageal or tracheal lacerations, or rupture. Radiographs showed no evidence of nonunion. The mean preoperative and the final follow-up C2 to C7 lordotic angles were 6.2±9.5 degrees and 9.4±7.6 degrees, respectively. The preoperative and the final follow-up lordotic angles of the fusion area were 2.0±8.1 degrees and 5.9±6.4 degrees, respectively. The average change in fusion area length was a 1.2 mm increase from before to after the operation and a 1.8 mm decrease from after the operation to the final follow-up. The average recovery rate of the Japanese Orthopaedic Association score was 63.0%. The surgical outcome of ACF with an ACP is satisfactory. CONCLUSIONS: Insertion of an ACP is a good solution for preventing problems with the grafted bone after ACF. Our study suggests that the indications for an anterior-only procedure for the management of cervical OPLL can be expanded.