Radiographical risk factors for major intraoperative blood loss during laminoplasty in patients with ossification of the posterior longitudinal ligament

Is Intraoperative Blood Loss Volume in Elderly Cervical Spine Injury Surgery Greater in Patients with Ankylosis? A Multicenter Survey

Introduction

Preoperative estimations of blood loss are important when planning surgery for cervical spine injuries in older adults. The association between ankylosis and blood loss in perioperative management is of particular interest. This multicenter database review aimed to evaluate the impact of ankylosis on surgical blood loss volume in elderly patients with cervical spine injury.

Methods

The case histories of 1512 patients with cervical spine injury at among 33 institutions were reviewed. After the exclusion of patients without surgery or whose blood loss or ankylosis status was unclear, 793 participants were available for analysis. Differences in blood loss volume were compared between the Ankylosis (+) group with ankylosis at the cervical level and the Ankylosis (-) group without by the inverse probability of treatment weighting (IPTW) method using a propensity score.

Results

Of the 779 patients (mean age: 75.0±6.3 years) eligible for IPTW calculation, 257 (32.4%) had ankylosis at the cervical level. The mean blood loss volume was higher in Ankylosis (+) patients than in Ankylosis (-) patients (P<0.001). This difference did not reach statistical significance when weighted by background factors, with mean blood loss of 244 mL and 188 mL, respectively, after adjustment.

Conclusions

This study revealed that ankylosis was significantly associated with increased blood loss volume when unadjusted by surgical time. Elderly patients with cervical spine injury accompanied by ankylosis appear predisposed to higher bleeding and severe hemorrhage, both as a result of the condition and their particular demographic characteristics.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification

PURPOSE

Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM.

RESULTS

Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%).

CONCLUSION

A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Risk Factors for Significant Intraoperative Blood Loss during Anterior Cervical Decompression and Fusion for Degenerative Cervical Diseases

OBJECTIVES

Anterior cervical decompression and fusion (ACF) has become a widely accepted surgical treatment for degenerative cervical diseases, but occasionally, significant intraoperative blood loss (SIBL), which is defined as IBL of 500 mL or more, will occur. We aimed to investigate the independent risk factors for SIBL during ACF for degenerative cervical diseases.

METHODS

We enrolled 1150 patients who underwent ACF for degenerative cervical diseases at our hospital between 2013 and 2019. The patients were divided into two groups: the SIBL group (n = 38) and the non-SIBL group (n = 1112). Demographic, surgical and radiographic data were recorded prospectively to investigate the independent risk factors for SIBL. For counting data, the chi-square test or Fisher's exact probability test was used. Student's t-test or the Mann-Whitney rank sum test was used for comparisons between groups of measurement data. Univariate analysis and multivariate logistic regression analysis were further used to analyze the significance of potential risk factors.

RESULTS

The incidence of SIBL during ACF was 3.3% (38/1150). A multivariate analysis revealed that female sex (odds ratio [OR], 6.285; 95% confidence interval [CI], 2.707-14.595; p < 0.001), corpectomy (OR, 3.872; 95% CI, 1.616-9.275; p = 0.002), duration of operation ≥150 min (OR, 8.899; 95% CI, 4.042-19.590; p < 0.001), C3 involvement (OR, 4.116; 95% CI, 1.808-9.369; p = 0.001) and ossification of posterior longitudinal ligament (OPLL) at the surgical level (OR, 6.007; 95% CI, 2.218-16.270; p < 0.001) were independent risk factors for SIBL. Patients with SIBL had more days of first-degree/intensive nursing (p = 0.003), longer length of stay (p = 0.003) and higher hospitalization costs (p = 0.023).

CONCLUSION

Female sex, corpectomy, duration of operation, C3 involvement and OPLL at the surgical level were independent risk factors for SIBL during ACF. SIBL in ACF was associated with more days of first-degree/intensive nursing, longer length of stay and higher hospitalization costs.

Predictors for hemostatic thrombin-gelatin matrix usage in spine surgery: a multicenter observational study

STUDY DESIGN

A prospective cohort study.

OBJECTIVES

Thrombin-gelatin matrix (TGM) is a rapid and potent hemostatic agent, but it has some limitations, including the cost and its preparation time. The purpose of this study was to investigate the current trend in the use of TGM and to identify the predictors for TGM usage in order to ensure its proper use and optimized resource allocation.

METHODS

A total of 5520 patients who underwent spine surgery in a multicenter study group within a year were included in the study. The demographic factors and the surgical factors including spinal levels operated, emergency surgery, reoperation, approach, durotomy, instrumented fixation, interbody fusion, osteotomy, and microendoscopy-assistance were investigated. TGM usage and whether it was routine or unplanned use for uncontrolled bleeding were also checked. A multivariate logistic regression analysis was used to identify predictors for unplanned use of TGM.

RESULTS

Intraoperative TGM was used in 1934 cases (35.0%), among which 714 were unplanned (12.9%). Predictors of unplanned TGM use were female gender (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.02-1.43, p = 0.03), ASA grade ≥ 2 (OR: 1.34, 95% CI: 1.04-1.72, p = 0.02), cervical spine (OR: 1.55, 95% CI: 1.24-1.94, p < 0.001), tumor (OR: 2.02, 95% CI: 1.34-3.03, p < 0.001), posterior approach (OR: 1.66, 95% CI: 1.26-2.18, p < 0.001), durotomy (OR: 1.65, 95% CI: 1.24-2.20, p < 0.001), instrumentation (OR: 1.30, 1.03-1.63, p = 0.02), osteotomy (OR: 5.00, 2.76-9.05, p < 0.001), and microendoscopy (OR: 2.24, 1.84-2.73, p < 0.001).

CONCLUSIONS

Many of the predictors for unplanned TGM use have been previously reported as risk factors for intraoperative massive hemorrhaging and blood transfusion. However, other newly revealed factors can be predictors of bleeding that is technically challenging to control. While routine usage of TGM in these cases will require further justification, these novel findings are valuable for implementing preoperative precautions and optimizing resource allocation.

Incidence and risk factors of postoperative symptomatic spinal epidural hematoma in cervical spine surgery: a single center, retrospective study of 18,220 patients

PURPOSE

The goal of this research is to explore the incidence and risk factors of symptomatic spinal epidural hematoma (SSEH) following cervical spine surgery.

METHODS

Patients with SSEH from January 2009 to February 2019 were identified as hematoma group. Two control subjects without SSEH were randomly selected for each patient in SSEH group as control group. We collected gender, age, body mass index (BMI), ossification of the posterior ligament (OPLL), comorbidities, anti-platelet or anti-coagulate treatment, coagulation function, segments, instrumental fixation, surgical approach, surgical procedure, duration of surgery and estimated blood loss, which might affect the occurrence of symptomatic epidural hematoma. T-test and Chi-square test were used to univariable test. Multifactor logistic regression analysis was used to investigate the correlation with symptomatic epidural hematoma, furthermore its causes were explored.

RESULTS

Among 18,220 patients, 43 subjects developed SSEH, the incidence was 0.24%. The median time from the end of index surgery to SSEH was 150  min (25 and 75 percentile: 85  min to 290  min). The neurologic function before evacuation by modified Frankel scale is grade B in 5 patients, C in 32 patients, grade D in 6 patients. All patients' symptoms relieved partially or completely after evacuation. All patients with neurologic deficit worse than grade C pre-evacuation had at least one-grade improvement except for one patient. Multifactor logistic regression revealed OPLL involved segments are significantly correlated to the incidence of postoperative symptomatic epidural hematoma (P < 0.05), with a cut-off value of 1.5 levels.

CONCLUSION

OPLL involved segments are significantly correlated to the incidence of postoperative symptomatic epidural hematoma.

Thrombocytopenia Associated with Unrecognized Non-Alcoholic Fatty Liver Disease Is an Independent Predictor of Perioperative Significant Blood Loss in Cervical Laminoplasty

OBJECTIVE

To identify risk factors for significant blood loss (SBL) in cervical laminoplasty, especially regarding thrombocytopenia and coagulopathy resulting from non-alcoholic fatty liver disease (NAFLD).

METHODS

We retrospectively investigated differences in patient background data, laboratory data at the time of admission, and surgery-related data of 317 patients who underwent cervical laminoplasty and were divided into SBL (estimated blood loss [EBL] + drainage [D] ≥500 g) and non-SBL (EBL + D < 500 g) groups. To evaluate liver status, we used the fibrous 4 index and considered fibrous 4 index ≥1.85 as a representative phenotype for NAFLD with liver fibrosis. In addition, the risk factor for perioperative SBL was investigated using multiple logistic regression analysis, and the cutoff value was calculated.

RESULTS

Incidence of perioperative SBL in cervical laminoplasty was 7.3% (23/317). Compared with the non-SBL group, the SBL group demonstrated significantly lower platelet count (PLT), lower aspartate aminotransferase, longer operation time, and greater number of opened laminae. According to multivariate analysis, lower PLT and a greater number of opened laminae were identified as significant risk factors for perioperative SBL. The cutoff value of PLT for predicting SBL was determined to be 16.7 × 10⁴/μL using a receiver operating characteristic curve. The liver fibrosis group revealed significantly lower PLT and greater EBL + D than the non-liver fibrosis group.

CONCLUSIONS

Thrombocytopenia is an independent predictor of perioperative SBL in cervical laminoplasty. Thus, patients with mild thrombocytopenia that may be associated with NAFLD must be carefully monitored to avoid perioperative SBL.

Risk factors for surgical complications in the management of ossification of the posterior longitudinal ligament

BACKGROUND CONTEXT

Ossification of the posterior longitudinal ligament (OPLL) is a progressive, debilitating disease most commonly affecting the cervical spine. When compared to other degenerative pathologies, OPLL procedures carry a significantly higher risk of complications owing to increased case complexity and technical difficulties. Most previous studies have focused on functional outcomes and few have reported on risk factors for postoperative complications in OPLL patients.

PURPOSE

To identify clinical and radiological risk factors of surgical complications following treatment for cervical OPLL STUDY DESIGN: Retrospective review PATIENT SAMPLE: One hundred thirty-one patients with cervical myelopathy secondary to OPLL who underwent surgical decompression with complete 2-year follow-up.

OUTCOME MEASURES

Surgical and medical postoperative complications were analyzed. Revision surgery rates and mortality rates were recorded.

METHODS

Clinical, surgical, and radiological characteristics were collected for each patient. Complications within 30 days were identified. Univariate and multivariate analysis were performed to identify risk factors for surgical complications.

RESULTS

There were 39 (29.8%) surgical complications in the cohort, which included C5 palsy (7.6%), dural tear (3.1%), surgical site infection (3.1%), and epidural hematoma (1.5%). 2-year revision and mortality rates were 4.6% and 2.3%, respectively. Univariate analysis revealed that blood loss ≥750mL (OR 3.42, p=0.028), operative duration ≥5.5 hours (OR 3.16, p=0.008), hill-type OPLL (OR 3.08, p=0.011), K-line (-) OPLL (OR 5.39, p<0.001), and presence of a double-layer sign (OR 3.79, p=0.002) were significant risk factors. In multivariate analysis, only hill-type OPLL (OR 2.61, p=0.048) and K-line (-) OPLL (OR 2.98, p=0.031) were found to be significant. Patients with both hill-type and K-line (-) OPLL had a 3.5 times risk of developing surgical complications (p=0.009).

CONCLUSIONS

Patients with OPLL have a higher risk of perioperative surgical complications if they had a hill-shaped OPLL and K-line (-) OPLL on preoperative imaging studies. To the best of the authors' knowledge, this study is the first to link hill-type and K-line (-) OPLL morphology as risk factors for perioperative surgical complications.

Influence of K-line on intraoperative and hidden blood loss in patients with ossification of the posterior longitudinal ligament when undergoing unilateral open-door laminoplasty

Background

The K-line is a virtual straight line that connects the midpoints of the anteroposterior spinal canal diameter from C2 to C7 on a cervical lateral X-ray film. Patients with cervical ossification of the posterior longitudinal ligament (OPLL), in which the peak of the OPLL exceeds the K-line (K-line [-]), are less likely to experience sufficient decompression after laminoplasty compared with patients for whom the OPLL does not exceed the K-line (K-line [+]). This retrospective study investigated the influence of K-line position relative to the OPLL on intraoperative and hidden blood loss during unilateral open-door laminoplasty for OPLL.

Methods

Data were retrospectively analyzed of 108 patients with OPLL who underwent unilateral open-door laminoplasty between April 2015 and March 2018. Patient cases were categorized as K-line (+) or (-). The evaluated perioperative parameters were haematocrit, haemoglobin, intraoperative and hidden blood loss, surgical time, postoperative drainage, and complications. Radiological parameters included ossification occupancy ratio and C2-7 lordosis.

Results

The K-line (+) and K-line (-) groups were statistically comparable with regard to age, gender, body mass index, OPLL classification, medication history, C2-7 lordosis, postoperative haemoglobin and haematocrit, postoperative drainage, hidden blood loss, and complications. The occupying ratio of the K-line (-) group was significantly greater than that of the K-line (+) group (49.5 ± 15.3% cf. 42.3 ± 10.1%; P = 0.006), and the intraoperative blood loss was also significantly higher (286 ± 110.5 mL cf. 205.5 ± 98.3 L, P = 0.003). The hidden blood loss of the K-line (-) group was higher than that of the K-line (+), but not significantly (295.5 ± 112.6 mL cf. 265.6 ± 103.8 mL; P = 0.072).

Conclusion

Intraoperative and hidden blood loss associated with unilateral open-door laminoplasty can be predicted by the spatial relationship of the K-line and osteophyte. This relationship is a simple and practical index that may help surgeons determine the appropriate surgical strategy for patients with OPLL.

A sliding scale to predict postoperative complications undergoing posterior spine surgery

BACKGROUND

There is a lack of consensus of operative time (OT) and estimated blood loss (EBL) for elderly patients based on the predicted risk of complications after posterior spine surgery. The purpose of this study was to evaluate the effect of age, OT, and EBL on the postoperative complication risk and to develop a simple sliding scale.

METHODS

We explored prospectively collected data of consecutive patients who underwent posterior spine surgery in seven tertiary referral hospitals from November 2013 to May 2016. Age (<70, 70-74, 75-79, 80-84, ≥85 years), OT (<2, 2-<3, 3-<4, 4-<5, ≥5 h), and EBL (<500, 500-<1000, 1000-<1500, 1500-<2000, ≥2000 ml) were categorized ranging from 1 (lowest) to 5 (highest). The association between the crude cumulative categories' number and the incidence of complications was analyzed. We further evaluated the association by re-categorizing the cumulative number into three groups (3-4, 5-10, ≥11).

RESULTS

Total of 2416 patients (median age: 70 years old) were enrolled and major complications were observed in 75 (3.1%) patients. Age, OT, and EBL showed similar odds ratio (1.18-1.19) as each category increased. The cumulative categories' number fitted the estimate complication risk (Hosmer-Lemeshow P = 0.87), and statistically significant trend was observed between predicted and actual complication rates (Cochran-Armitage test, P < 0.001). When cumulative categories' numbers were stratified into three groups, significant increasing trend of risk were observed (Mantel-Haenszel P < 0.001). Based on the categorical numbers, we proposed a simple sliding scale.

CONCLUSION

Our data indicated that the risk of postoperative complication was associated with cumulative score based on increased age, OT, and EBL. A simple sliding scale was developed based on these factors, which may be useful to predict complication risk after posterior spine surgery.

Comparison of the operative time for open door laminoplasty using titanium plate spacers or hydroxyapatite block spacers: a retrospective study

Abstract

Background

Titanium plate (TP) and hydroxyapatite (HA) spacers are widely used during open-door laminoplasty, performed with the patient in a prone position. Reducing operative time is an important consideration, particularly to reduce the risk of postoperative complications in older patients. The purpose of this retrospective cohort study was to compare the operative time for open-door laminoplasty using TP or HA spacers.

Methods

Consecutive patients with a spinal cord injury, without bone injury, and ≥ 50 years of age were included. Multivariate regression analysis was used to compare the operative time between patients in the TP and HA group, adjusting for known factors that can influence surgical and postoperative outcomes. Propensity score matching was used to confirm the robustness of the primary outcome. The cumulative incidence of postoperative complications over 1-year after surgery was also compared.

Results

Of the 164 patients forming our study group, TP spacers were used in 62 and HA in 102. Operative time was significantly shorter for the TP (128 min) than HA (158 min) group (p < 0.001). Both multivariate and propensity score matching analyses confirmed a significant reduction in operative time for the TP, compared to HA, group (regression coefficient, − 30 min and − 38 min, p < 0.001 and p < 0.001, respectively). There was no significant difference in the cumulative incidence of postoperative complications.

Conclusions

The use of TP spacers reduced the operative time for cervical open-door laminoplasty by about 30 min, compared to the use of HA spacers, with no difference in the rate of postoperative complications.

Risk Factors for Significant Intraoperative Blood Loss During Unilateral Expansive Open-Door Cervical Laminoplasty for Cervical Compressive Myelopathy

OBJECTIVE

Unilateral expansive open-door cervical laminoplasty is an effective and safe procedure for cervical compressive myelopathy but occasionally is accompanied with significant intraoperative blood loss (SIBL). The aim of the present study was to elucidate the risk factors for SIBL in patients undergoing cervical laminoplasty for multilevel cervical compressive myelopathy and to identify the effect of SIBL on neurologic complications.

METHODS

A total of 215 patients who received cervical laminoplasty between January 2010 and August 2016 were enrolled in the study. SIBL was defined as 500 mL or more of blood volume during surgery. Patients were subdivided into 2 groups according to whether they suffered from SIBL (n = 26) or not (n = 189). Patient characteristics and clinical data were collected. Univariate and multivariable analysis were performed to identify independent risk factors for SIBL.

RESULTS

The incidence of SIBL during unilateral expansive open-door cervical laminoplasty was 12.1%. The multivariable logistic regression analysis showed Pavlov ratio (odds ratio [OR] 0.002, P = 0.009), ossification of the posterior longitudinal ligament (OR 2.677, P = 0.038), and number of complete hinge fractures (OR 1.842, P = 0.015) were independent risk factors for SIBL during cervical laminoplasty. Patients with SIBL during cervical laminoplasty had a greater rate of neurologic complications during hospitalization (P = 0.012), worse neurologic recovery rate at discharge (P = 0.01), and longer postoperative length of stay (P = 0.003).

CONCLUSIONS

This study suggested that Pavlov ratio, ossification of the posterior longitudinal ligament, and number of complete hinge fractures were independent risk factors for SBIL during cervical laminoplasty. SIBL in cervical laminoplasty was associated with greater neurologic complications and worse neurologic functional recovery.

Risk factors for predicting increased surgical drain output in patients after anterior cervical corpectomy and fusion

Background

Although measures to reduce and treat the postoperative surgical drain output are discussed, along with the increased interest in causative factors related to the prevention and treatment reported by many studies, these are still controversial.

Methods

A retrospective study was conducted on a consecutive series of 217 patients who had underwent ACCF between January 2016 and March 2017. Patients were categorized based on normal or increased total drain output. These two groups were compared for demographic distribution and clinical data to investigate the predictive factors of increased drain output by multivariate analysis.

Results

The overall incidence rate of increased drain output after ACCF was 16.6%. There are no significant differences in sex, BMI, history of taking aspirin, and ASA classification between the two groups (P > 0.05). Of the patients with increased drain output, a significantly higher proportion of patients have OPLL in the surgical level, 18 (50.0%) versus 33 (18.2%) (P = 0.000). The mean age was 60.67 ± 8.18 years versus 54.41 ± 10.05 years (P = 0.001). Number of discs involved was 2.42 ± 0.50 versus 2.02 ± 0.65 (P = 0.001). Operation time was 112.22 ± 16.49 min versus 105.21 ± 17.89 min (P = 0.031). Intraoperative blood loss was 109.86 ± 62.02 mL versus 87.83 ± 56.40 mL (P = 0.036). Logistic regression analysis showed that age (OR, 1.075; p = 0.003), history of smoking (OR, 2.792; p = 0.021), OPLL in surgical level (OR, 2.107; p = 0.001), and number of discs involved (OR, 2.764; p = 0.003) maintained its significance in predicting likelihood of increased surgical drain output.

Conclusions

The occurrence of increased drain output after ACCF is most likely multifactorial and is related to age, history of smoking, OPLL in surgical level, and number of discs involved.

Outcomes of Surgical Treatment for Thoracic Myelopathy: A Single-institutional Study of 73 Patients

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim was to investigate the clinical outcomes in patients with thoracic myelopathy in a single institution and to identify prognostic factors for poor outcomes.

SUMMARY OF BACKGROUND DATA

Because of the rarity of thoracic myelopathy, a few studies have analyzed a large number of clinical results for patients with thoracic myelopathy treated in a single institution.

METHODS

Seventy-one patients who underwent surgical treatment for thoracic myelopathy between 2000 and 2011 in a single institution were included in this analysis. We investigated the patients' characteristics, surgical outcomes, and prognostic factors for poor outcomes.

RESULTS

Of the 73 patients, eight patients had disc herniation (DH) or spinal stenosis (SS), 10 patients had ossification of the posterior longitudinal ligament (OPLL), 40 patients had ossification of the ligamentum flavum (OLF), and 15 patients had OPLL + OLF. The mean patient age at the time of surgery was 61.9 years. Thoracic myelopathy was caused by OPLL and/or OLF in 65 patients (89%). Fifty-eight patients underwent laminectomy, eight patients underwent laminectomy and posterior fusion, four patients underwent OPLL extirpation and posterior fusion, and three patients underwent OPLL extirpation. The mean Japanese Orthopedic Association Scoring System scores before surgery and at the final follow-up examination were 6.0 ± 1.8 and 7.7 ± 2.0 points, respectively, yielding a mean recovery rate of 30% ± 43%. The JOA score improved significantly postoperatively (P < 0.05). Risk factors for poor outcomes were longer preoperative symptom duration, preoperative JOA score < 7, and OPLL and/or OLF. Large blood loss volume was significantly associated with a worse postoperative JOA score.

CONCLUSION

A considerable degree of neurological recovery was observed after surgical treatment in patients with thoracic myelopathy. Prognostic factors for poor outcomes were longer preoperative duration of symptoms, worse preoperative symptoms, OPLL and/or OLF, and large volume of intraoperative bleeding.

LEVEL OF EVIDENCE

4.

Surgical Treatment for Thoracic Myelopathy Due to Simultaneous Ossification of the Posterior Longitudinal Ligament and Ligamentum Flavum at the Same Level

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim of this study was to assess the clinical outcomes of surgery in patients with simultaneous ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) at the same thoracic spine level and identify the risk factors for poor outcomes.

SUMMARY OF BACKGROUND DATA

OPLL complicated with OLF in the thoracic spine is a rare condition. The optimal treatment option for thoracic myelopathy due to OPLL and OLF remains controversial, and high risk of postoperative paralysis remains a major complication.

METHODS

We conducted a retrospective review of clinical and radiographic records of 15 patients who underwent surgery for simultaneous OPLL and OLF at the same level.

RESULTS

Simultaneous OPLL and OLF occurred in the upper thoracic spine in 3 patients (20%), mid-thoracic spine in 10 patients (67%), and lower thoracic spine in 2 patients (13%). Six, 4, 2, and 3 patients underwent posterior decompression, posterior decompression and fusion, posterior decompression and circumferential decompression through a posterior approach, and circumferential decompression and posterior fusion, respectively. The mean Japanese Orthopaedic Association score before surgery and at the final follow-up was 5.7±1.9 and 7.0±2.1 points, respectively, yielding a mean recovery rate of 16.5%. However, no significant difference was observed between preoperative and postoperative Japanese Orthopaedic Association scores. Two patients with mid-thoracic lesions reported postoperative lower extremity weakness. Mid-thoracic lesions and considerable blood loss were risk factors for poor surgical outcome.

CONCLUSIONS

Simultaneous OPLL and OLF in the mid-thoracic spine was observed in two thirds of the patients. We suggest that simultaneous OPLL and OLF in this area has a relatively poor recovery and may be very challenging and risky to treat, regardless of the surgical method selected, and recommend early surgery for OPLL and OLF in the mid-thoracic spine.

A systematic review of clinical and surgical predictors of complications following surgery for degenerative cervical myelopathy

OBJECTIVE

Although generally safe and effective, surgery for the treatment of cervical spondylotic myelopathy (CSM) is associated with complications in 11%-38% of patients. Several predictors of postoperative complications have been proposed but few are used to detect high-risk patients. A standard approach to identifying "at-risk" patients would improve surgeons' ability to prevent and manage these complications. The authors aimed to compare the complication rates between various surgical procedures used to treat CSM and to identify patient-specific, clinical, imaging, and surgical predictors of complications.

METHODS

The authors conducted a systematic review of the literature and searched MEDLINE, MEDLINE in Process, EMBASE, and Cochrane Central Register of Controlled Trials from 1948 to September 2013. Cohort studies designed to evaluate predictors of complications and intervention studies conducted to compare different surgical approaches were included. Each article was critically appraised independently by 2 reviewers, and the evidence was synthesized according to the principles outlined by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) Working Group.

RESULTS

A total of 5472 citations were retrieved. Of those, 60 studies met the inclusion criteria and were included in the review. These studies included 36 prognostic cohort studies and 28 comparative intervention studies. High evidence suggests that older patients are at a greater risk of perioperative complications. Based on low evidence, other clinical factors such as body mass index, smoking status, duration of symptoms, and baseline severity score, are not predictive of complications. With respect to surgical factors, low to moderate evidence suggests that estimated blood loss, surgical approach, and number of levels do not affect rates of complications. A longer operative duration (moderate evidence), however, is predictive of perioperative complications and a 2-stage surgery is related to an increased risk of major complications (high evidence). In terms of surgical techniques, higher rates of neck pain were found in patients undergoing laminoplasty compared with anterior spinal fusion (moderate evidence). In addition, with respect to laminoplasty techniques, there was a lower incidence of C-5 palsy in laminoplasty with concurrent foraminotomy compared with nonforaminotomy (low evidence).

CONCLUSIONS

The current review suggests that older patients are at a higher risk of perioperative complications. A longer operative duration and a 2-stage surgery both reflect increased case complexity and can indirectly predict perioperative complications.