Comparison of Inpatient and Outpatient Preoperative Factors and Postoperative Outcomes in 2-Level Cervical Disc Arthroplasty

Unplanned readmissions following ambulatory spine surgery: assessing common reasons and risk factors

BACKGROUND CONTEXT

Although outpatient spine surgery is becoming increasingly popular in the United States, unplanned readmission following outpatient surgery remains a significant postoperative concern.

PURPOSE

This study aimed to (1) describe the incidence and timing of 30-day unplanned readmission after ambulatory lumbar and cervical spine surgery (2) evaluate the common reasons for readmission, and (3) identify factors associated with readmission in this population.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Patients who underwent ambulatory cervical or lumbar spine surgery between 2015 and 2020 were identified in the National Surgical Quality Improvement Program (NSQIP) database.

OUTCOME MEASURES

Hospital readmission within 30 postoperative days.

METHODS

Patients who underwent ambulatory cervical or lumbar spine surgery between 2015 and 2020 were identified using the National Surgical Quality Improvement Program (NSQIP) database. Reasons for and timing of unplanned readmissions were recorded. Multivariable poisson regressions were employed to determine any independent predictors of readmission.

RESULTS

A total of 33,092 ambulatory cervical and 68,115 ambulatory lumbar spine surgery patients were identified. Incidences of 30-day readmission were 3.37% and 3.07% among cervical and lumbar patients, respectively. The most common surgical site-related reasons for readmission included uncontrolled pain, recurrence of disc herniation or major symptom, and postoperative hematoma/seroma. Common nonsurgical site-related reasons included gastrointestinal, neurological, and cardiovascular complications. Factors associated with readmission among cervical patients included age ≥55, BMI ≥35, functional dependence, diabetes, smoking, COPD, and steroid use, whereas factors associated with readmission following lumbar spine surgery included age ≥65, female sex, BMI ≥35, functional dependence, ASA ≥3, diabetes, smoking, COPD, and hypertension (p<.05 for all).

CONCLUSION

This study highlights the common reasons and factors associated with unplanned readmission following ambulatory spine surgery. Consideration of these factors may be critical to ensuring appropriate patient selection for ambulatory spine surgery.

Clinical Effectiveness of Artificial Disc Replacement in Comparison With Anterior Cervical Discectomy and Fusion in the Patients With Cervical Myelopathy: Systematic Review and Meta-analysis

OBJECTIVE

Cervical myelopathy (CM) describes the compressive cervical spinal cord state, often accompanied by serious clinical condition, by herniated disc or hypertrophied spurs or ligament. Anterior cervical discectomy and fusion (ACDF) has been frequently employed as conventional surgical solution for this CM despite its inherent biomechanical handicap. Alternatively, an artificial disc replacement (ADR) preserves cervical motion while still decompressing the spinal canal and neural foramen. This analysis elaborated to clarify the potential benefits of ADR application to CM over ACDF from the conglomerated results of the past references.

METHODS

A literature search was performed using MEDLINE, Embase, Cochrane review, and KMbase databases from the studies published until March 2023. Six studies (3 randomized controlled study [RCTs] and 3 non-RCTs) were included in a qualitative and quantitative synthesis. Data were extracted and analyzed using a random effects model to obtain effect size and its statistical significance. Quality assessment and evidence level were established in accordance with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology.

RESULTS

Among 6 studies, 2 studies showed that ADR group achieved significantly better clinical improvement than the ACDF group, while the rest 4 studies revealed no significant difference. A meta-analysis showed better clinical outcomes with or without statistical significance. The level of evidence was low because of inconsistency and imprecision.

CONCLUSION

ADR was superior or at least, not inferior to ACDF in terms of functional recovery. However, its application to the CM patients is merely empowered with weak strength due to low level of evidence.

No Significant Differences in Postoperative Complications Between Outpatient and Inpatient Single-level or Multiple-level Cervical Disk Replacement for Cervical Radiculopathy

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To investigate the safety profile of outpatient versus inpatient single-level and multiple-level cervical disk replacement (CDR) by analyzing one- and two-year surgical outcomes and 90-day medical complications using a large patient database.

SUMMARY OF BACKGROUND DATA

CDR is becoming a more desirable option for patients undergoing cervical spine procedures. Unlike anterior cervical diskectomy and fusion, CDR is motion-preserving and has been shown to reduce rates of adjacent segment disease. Current literature investigating outpatient versus inpatient CDR has shown a similar safety profile among the two cohorts. However, most of these studies have relatively small sample sizes with short-term follow-up.

MATERIALS AND METHODS

A retrospective cohort study was done using the PearlDiver patient database between 2010 and 2019. Patients who underwent single-level and multiple-level CDR with a follow-up of at least two years were identified. Patients within each procedure cohort were subdivided into an outpatient and an inpatient group. Univariate and multivariable analyses were performed.

RESULTS

In total, 2294 patients underwent single-level CDR of which 506 patients underwent outpatient CDR and 1788 underwent inpatient CDR. In total, 236 patients underwent multiple-level CDR of which 49 patients underwent outpatient CDR and 187 underwent inpatient CDR. In the single-level CDR cohort, patients undergoing outpatient CDR were found to have lesser odds of a decompressive laminectomy at one year following the initial procedure (odds ratio=0.471; 95% confidence interval: 0.205-0.945; P =0.05). No significant differences in one- and two-year surgical complications, or 90-day postoperative complications, were found on multivariate analysis of outpatient versus inpatient multiple-level CDR.

CONCLUSION

Our study found that performing single-level and multiple-level CDR on an outpatient basis has a similar safety profile to patients who underwent these procedures in an inpatient setting.

LEVEL OF EVIDENCE

3.

Factors Causing Delay in Discharge in Patients Eligible for Ambulatory Lumbar Fusion Surgery

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the postoperative factors that led delayed discharge in patients who would have been eligible for ambulatory lumbar fusion (ALF).

SUMMARY OF BACKGROUND DATA

Assessing postoperative inefficiencies is vital to increase the feasibility of ALF.

MATERIALS AND METHODS

Patients who underwent single-level minimally invasive transforaminal lumbar interbody fusion and would have met the eligibility criteria for ALF were included. Length of stay (LOS); time in postanesthesia recovery unit (PACU); alertness and neurological examination, and pain scores at three and six hours; type of analgesia; time to physical therapy (PT) visit; reasons for PT nonclearance; time to per-oral (PO) intake; time to voiding; time to readiness for discharge were assessed. Time taken to meet each discharge criterion was calculated. Multiple regression analyses were performed to study the effect of variables on postoperative parameters influencing discharge.

RESULTS

Of 71 patients, 4% were discharged on the same day and 69% on postoperative day 1. PT clearance was the last-met discharge criterion in 93%. Sixty-six percent did not get PT evaluation on the day of surgery. Seventy-six percent required intravenous opioids and <60% had adequate pain control. Twenty-six percent had orthostatic intolerance. The median postoperative LOS was 26.9 hours, time in PACU was 4.2 hours, time to PO intake was 6.5 hours, time to first void was 6.3 hours, time to first PT visit was 17.7 hours, time to PT clearance was 21.8 hours, and time to discharge readiness was 21.9 hours. Regression analysis showed that time to PT clearance, time to PO intake, time to voiding, time in PACU, and pain score at three hours had a significant effect on LOS.

CONCLUSIONS

Unavailability of PT, surgery after 1  pm , orthostatic intolerance, inadequate pain control, prolonged PACU stay, and long feeding and voiding times were identified as modifiable factors preventing same-day discharge.

LEVEL OF EVIDENCE

4.

Advanced Technologies for Outpatient Lumbar Fusion: Barriers and Opportunities

BACKGROUND

In recent years, there has been increasing interest in outpatient spine surgery. Minimally invasive techniques have created an opportunity for ambulatory lumbar fusion, and these techniques increasingly involve advanced technologies such as navigation and robotics.

OBJECTIVE

To explore the barriers, advantages, and future predictions for such technology in the context of outpatient lumbar fusions.

METHODS

This is a narrative review of studies examining the advantages, limitations, and cost-effectiveness of navigation and spinal robotics in conjunction with the outcomes and costs of outpatient lumbar fusion.

RESULTS

Outpatient lumbar fusion is a growing trend with ample evidence of its safety, favorable patient outcomes, and cost savings. Navigation and spinal robotics are associated with improved instrumentation accuracy and fewer complications, and the long-term cost savings can make these technologies financially practical in the outpatient setting. Future capabilities with robotics will only increase their value.

CONCLUSIONS

Advanced technologies such as navigation and robotics are strategic long-term investments in the context of outpatient lumbar fusion.

CLINICAL RELEVANCE

The favorable outcomes and costs associated with navigation and robotics will be relevant to any spine surgeon interested in developing an outpatient lumbar fusion program.

LEVEL OF EVIDENCE: 5

Cervical and Lumbar Disc Arthroplasty: A Review of Current Implant Design and Outcomes

While spinal disc pathology has traditionally been treated using fusion-based procedures, recent interest in motion-preserving disc arthroplasties has grown. Traditional spinal fusion is associated with loss of motion, alteration of native spine kinematics, and increased risks of adjacent segment disease. The motion conferred by disc arthroplasty is believed to combat these complications. While the first implant designs resulted in poor patient outcomes, recent advances in implant design and technology have shown promising radiographic and clinical outcomes when compared with traditional fusion. These results have led to a rapid increase in the utilization of disc arthroplasty, with rates of cervical arthroplasty nearly tripling over the course of 7 years. The purpose of this review was to discuss the evolution of implant design, the current implant designs utilized, and their associated outcomes. Although disc arthroplasty shows significant promise in addressing some of the drawbacks associated with fusion, it is not without its own risks. Osteolysis, implant migration, and the development of heterotopic ossification have all been associated with disc arthroplasty. As interest in these procedures grows, so does the interest in developing improved implant designs aimed at decreasing these adverse outcomes. Though they are still relatively new, cervical and lumbar disc arthroplasty are likely to become foundational methodologies for the treatment of disc pathology.

Cervical Disc Replacement for Radiculopathy Versus Myeloradiculopathy: An MCID Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The aim was to compare the minimally clinically important difference (MCID) across multiple patient-reported outcomes (PROs) in patients undergoing cervical disc replacement (CDR) for cervical spondylotic radiculopathy versus myeloradiculopathy.

SUMMARY OF BACKGROUND DATA

To date, a limited number of studies have demonstrated mostly similar results in patients with cervical spondylotic radiculopathy or myeloradiculopathy undergoing CDR. However, each of these previous studies have focused on statistically significant differences, which may not correlate with patient perceived improvements in outcomes or success.

METHODS

Patients who underwent 1 or 2-level CDR with radiculopathy versus myeloradiculopathy were identified, and prospectively collected data was retrospectively reviewed. Demographic variables, preoperative diagnosis, and operative variables were collected for each patient. The following PROs were prospectively collected: Neck Disability Index (NDI), visual analog scale (VAS)-Neck, VAS-Arm, Short Form-12 Health Survey (SF-12) Physical Component Score (PCS), SF-12 Mental Component Score (MCS), PROMIS Physical Function (PF). An MCID analysis of PROs for each diagnosis group was performed and the percentage of patients achieving the MCID was compared between the two diagnosis groups.

RESULTS

Eight-five patients, of which 56% had radiculopathy and 44% had myeloradiculopathy. MCID analysis demonstrated that at 6-week, 12-week, and final postoperative follow-up there was no significant difference in the percentage of patients with radiculopathy or myeloradiculopathy achieving the MCID for each PRO assessed. In both diagnosis groups the percentage of patients achieving the MCID for each PRO continued to increase from the 6-week to final postoperative follow-up except for the SF-12 MCS in patients with myeloradiculopathy.

CONCLUSIONS

The percentage of patients achieving the MCID was not significantly different at each postoperative period assessed in the radiculopathy and myeloradiculopathy groups treated with CDR. In addition, the percentage of patients achieving the MCID continued to increase from 6 weeks to final follow-up in both groups for almost all PROs assessed.

Safety of Anterior Cervical Disc Arthroplasty in the Ambulatory Setting: an Eastern European Experience

Aim: Spine surgery has been gradually transitioning from the inpatient setting into ambulatory surgery centers (ASC) and as such, the safety of treating patients on an outpatient basis needs to be validated. Objective:In this study, we aimed to evaluate the safety of anterior cervical disc arthroplasty (CDA) performed in an ambulatory setting in an Eastern European population. All existing studies evaluating safety and efficiency of outpatient CDA have originated from high-volume ASCs from the USA. Methods:We retrospectively reviewed 103 consecutive patients who underwent outpatient CDA between January 2018 and February 2020 in order to assess the safety of outpatient single- and multi-level CDA procedures. Various operative data was collected, including adverse events. Results:One patient required reintervention for reposition of the implant, resulting in a reoperation rate of 0.97%. Of the total 149 levels treated, the risk of readmission per level treated was 0.67%. Other AEs included prolonged postoperative hoarseness (laryngeal nerve dysfunction) in two (1.94%) patients, which for one patient resolved within one year. There were no other cases of reintervention, hospital readmission, or postoperative emergency visits. Conclusion:To our knowledge, this is the first study to evaluate the safety of CDA in the ambulatory setting in an Eastern European population. Our data suggests that CDA may be considered safe in the outpatient setting in appropriately selected patients. The 30-day reintervention rate was 0.97%, while AE rate was 1.94%. The reoperation and AE rates were similar to or lower than the complication rates reported by large US outcome studies.

Comparison of the Safety of Outpatient Cervical Disc Replacement With Inpatient Cervical Disc Replacement: A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVES

Outpatient cervical disc replacement (CDR) has been performed with an increasing trend in recent years. However, the safety profile surrounding outpatient CDR remains insufficient. The present study systematically reviewed the current studies about outpatient CDR and performed a meta-analysis to evaluate the current evidence on the safety of outpatient CDR as a comparison with the inpatient CDR.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases comprehensively up to April 2020. Patient demographic data, overall complication, readmission, returning to the operation room, operating time were analyzed with the Stata 14 software and R 3.4.4 software.

RESULTS

Nine retrospective studies were included. Patients underwent outpatient CDR were significantly younger (mean difference [MD] = -1.97; 95% CI -3.80 to -0.15; P = .034) and had lower prevalence of hypertension (OR = 0.68; 95% CI 0.53-0.87; P = .002) compared with inpatient CDR. The pooled prevalence of overall complication was 0.51% (95% CI 0.10% to 1.13%) for outpatient CDR. Outpatient CDR had a 59% reduction in risk of developing complications (OR = 0.41; 95% CI 0.18-0.95; P = .037). Outpatient CDR showed significantly shorter operating time (MD = -18.37; 95% CI -25.96 to -10.77; P < .001). The readmission and reoperation rate were similar between the 2 groups.

CONCLUSIONS

There is a lack of prospective studies on the safety of outpatient CDR. However, current evidence shows outpatient CDR can be safely performed under careful patient selection. High-quality, large prospective studies are needed to demonstrate the generalizability of this study.

Cervical disc arthroplasty: What we know in 2020 and a literature review

Cervical disc arthroplasty (CDA) is a safe and effective option to improve clinical outcomes (e.g., NDI, VAS, and JOA) in degenerative cervical disc disease and compressive myelopathy. CDA's two main purported benefits have been that it maintains physiologic motion and thereby minimizes the biomechanical stresses placed on adjacent segments as compared to an ACDF. CDA might reduce the degeneration of adjacent segments, and the need for adjacent-level surgery. Reoperation rates of CDA have been reported to range from 1.8% to 5.4%, with a minimum 5-year follow-up. As the number of CDA procedures performed continues to increase, the need for revision surgery is also likely to increase. When performed skillfully in appropriate patients, CDA is an effective surgical technique to optimize clinical outcomes and radiological results. This review may assist surgical decision-making and enable a more effective and safer implementation of cervical arthroplasty for cervical degenerative disease.

Association of Duration of Preoperative Opioid Use with Reoperation After One-level Anterior Cervical Discectomy and Fusion in Nonmyelopathic Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to determine that rates of preoperative opioid use in patients undergoing single-level anterior discectomy and fusion (ACDF) without myelopathy and determine the association with reoperations over 5 years.

SUMMARY OF BACKGROUND DATA

Preoperative opioid use before cervical spine surgery has been linked to worse postoperative outcomes. However, no studies have determined the association of duration and type of opioid used with reoperations after ACDF.

METHODS

Patients undergoing single-level ACDF without myelopathy between 2007 and 2016 with at least 5-year follow-up were identified in one private insurance administrative database. Preoperative opiate use was divided into acute (within 3 months), subacute (acute use and use between 3 and 6 months), and chronic (subacute use and use before 6 months) and by the opiate medication prescribed (tramadol, oxycodone, and hydrocodone). Postoperative rates of additional cervical spine surgery were determined at 5 years and multivariate logistic regression was used to determine the association of preoperative opiates with additional surgery.

RESULTS

Of 445 patients undergoing single-level ACDF without myelopathy, 66.3% were taking opioid medications before surgery. The most commonly used preoperative opioid was hydrocodone (50.3% acute use, 24.7% chronic use). Opioid-naïve patients had a 5-year reoperation rate of 4.7%, compared to 25.0%, 15.5%, and 23.3% with chronic preoperative use of tramadol, hydrocodone, and oxycodone. In multivariate analysis, controlling for age, sex, and Charlson Comorbidity Index, chronic use of hydrocodone (odds ratio [OR] = 2.08, P = 0.05), oxycodone (OR = 4.46, P < 0.01), and tramadol (OR = 4.01, P = 0.01) were all associated with increased reoperations. However, acute use of hydrocodone, oxycodone, and tramadol was not associated with reoperations (P > 0.05).

CONCLUSION

Both subacute and chronic use of common lower-dose opioid medications is associated with increased reoperations after single-level ACDF in nonmyelopathic patients. This information is critical when counseling patients preoperatively and developing preoperative opioid cessation programs.Level of Evidence: 3.

Comparison of Two-level Cervical Disc Replacement Versus Two-level Anterior Cervical Discectomy and Fusion in the Outpatient Setting

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the safety of two-level cervical disc replacement (CDR) in the outpatient setting.

SUMMARY OF BACKGROUND DATA

Despite growing interest in CDR, limited data exist evaluating the safety of two-level CDR in the outpatient setting.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was queried for all two-level anterior cervical discectomy and fusion (ACDF) and CDR procedures between 2015 and 2018. Demographics, comorbidities, and 30-day postoperative complication rates of outpatient two-level CDR were compared to those of inpatient two-level CDR and outpatient two-level ACDF. Radiographic data are not available in the NSQIP.

RESULTS

A total of 403 outpatient CDRs were compared to 408 inpatient CDRs and 4134 outpatient ACDFs. Outpatient CDR patients were older and more likely to have pulmonary comorbidities compared to inpatient CDR (P < 0.03). Outpatient CDR patients were less likely to have an American Society of Anesthesiologists class ≥2 and have hypertension compared to outpatient ACDF patients (P < 0.0001). Outpatient CDR had a lower 30-day readmission rate (0.5% vs. 2.5%, P = 0.02) and lower 30-day reoperation rate (0% vs. 1%, P = 0.047) compared to inpatient CDR. Outpatient CDR had a lower readmission rate (0.5% vs. 2.1%, P = 0.03) compared to outpatient ACDF, but there was no difference in reoperation rates between the two procedures (0% vs. 0.8%, P = 0.07). Outpatient CDR had an overall complication rate of 0.2%, inpatient CDR had a complication rate of 0.9%, and outpatient ACDF had a complication rate of 1.3%. These differences were not significant.

CONCLUSION

To our knowledge, this is the largest multicenter study examining the safety of two-level outpatient CDR procedures. Outpatient two-level CDR was associated with similarly safe outcomes when compared to inpatient two-level CDR and outpatient two-level ACDF. This suggests that two-level CDR can be performed safely in the outpatient setting.Level of Evidence: 3.

Predictors of Readmission and Prolonged Length of Stay After Cervical Disc Arthroplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of the study was to assess which factors increase risk of readmission within 30 days of surgery or prolonged length of stay (LOS) (≥2 days) after cervical disc arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

Several studies have shown noninferiority at mid- and long-term outcomes after cervical disc arthroplasty (CDA) compared to anterior cervical discectomy and fusion ACDF, but few have evaluated short-term outcomes regarding risk of readmission or prolonged LOS after surgery.

METHODS

Demographics, comorbidities, operative details, postoperative complications, and perioperative outcomes were collected for patients undergoing single level CDA in the National Surgical Quality Improvement Program (NSQIP) database. Patients with prolonged LOS, defined as >2 days, and readmission within 30 days following CDA were identified. Univariable and multivariable logistic regression models were used to identify risk factors for prolonged LOS and readmission.

RESULTS

A total of 3221 patients underwent single level CDA. Average age was 45.6 years (range 19-82) and 53% of patients were male. A total of 472 (14.7%) experienced a prolonged LOS and 36 (1.1%) patients were readmitted within 30 days following surgery. Predictors of readmission were postoperative superficial wound infection (odds ratio [OR] = 73.83, P < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 1.98, P = 0.048), and body mass index (BMI) (OR = 1.06, P = 0.02). Female sex (OR = 1.76, P < 0.001), diabetes (OR = 1.50, P = 0.024), postoperative wound dehiscence (OR = 13.11, P = 0.042), ASA class (OR = 1.43, P < 0.01), and operative time (OR = 1.01, P < 0.001) were significantly associated with prolonged LOS.

CONCLUSION

From a nationwide database analysis of 3221 patients, wound complications are predictors of both prolonged LOS and readmission. Patient comorbidities, including diabetes, higher ASA classification, female sex, and higher BMI also increased risk of prolonged LOS or readmission.Level of Evidence: 3.

Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement

Objective

To evaluate outcomes of cervical disc replacement (CDR) in patients with nonlordotic alignment.

Methods

Patients who underwent CDR were retrospectively reviewed and divided into 3 cohorts: (1) neutral/lordotic segmental and C2–7 Cobb angle (L), (2) nonlordotic segmental Cobb angle, lordotic C2–7 Cobb angle (NL-S), and (3) nonlordotic segmental and C2–7 Cobb angle (NL-SC). Radiographic and patient-reported outcomes (PROMs) were compared.

Results

One-hundred five patients were included (L: 37, NL-S: 30, NL-SC: 38). A significant gain in segmental lordosis was seen in all cohorts at < 6 months (L: -1.90° [p = 0.007]; NL-S: -5.16° [p < 0.0001]; NL-SC: -6.00° [p < 0.0001]) and ≥ 6 months (L: -2.07° [p = 0.031; NL-S: -6.04° [p < 0.0001]; NL-SC: -6.74° [p < 0.0001]), with greater lordosis generated in preoperatively nonlordotic cohorts (p < 0.0001). C2–7 lordosis improved in the preoperatively nonlordotic cohort (NL-SC: 8.04°) at follow-up of < 6 months (-4.15°, p=0.003) and ≥ 6 months (-6.40°, p=0.003), but not enough to create lordotic alignment (< 6 months: 3.89°; ≥ 6 months: 4.06°). All cohorts showed improvement in Neck Disability Index, visual analogue scale (VAS) neck, and VAS arm, without significant difference among groups in the amount of improvement (≥ 6-month PROMs follow-up=69%).

Conclusion

In patients without major kyphotic deformity, CDR has the potential to generate and maintain lordosis and improve PROMs in the short-term, and can be an effective treatment option for patients with nonlordotic alignment.

Comparison of the safety of outpatient cervical disc replacement with inpatient cervical disc replacement: A protocol for a meta-analysis

BACKGROUND

Cervical disc replacement (CDR) has been widely used as an effective treatment for cervical degenerative disc diseases in recent years. However, the cost of this procedure is very high and may bring a great economic burden to patients and the health care system. It is reported that outpatient procedures can reduce nearly 30% of the costs associated with hospitalization compared with inpatient procedures. However, the safety profile surrounding outpatient CDR remains poorly resolved. This study aims to evaluate the current evidence on the safety of outpatient CDR METHODS:: Four English databases were searched. The inclusion and exclusion criteria were developed according to the PICOS principle. The titles and abstracts of the records will be screened by 2 authors independently. Records that meet the eligibility criteria will be screened for a second time by reading the full text. An extraction form will be established for data extraction. Risk of bias assessment will be performed by 2 authors independently using Cochrane risk of bias tool or Newcastle-Ottawa scale. Data synthesis will be conducted using Stata software. Heterogeneity among studies will be assessed using I test. The funnel plot, Egger regression test, and Begg rank correlation test will be used to examine the publication bias.

RESULTS

The results of this meta-analysis will be published in a peer-review journal.

CONCLUSION

This will be the first meta-analysis that compares the safety of outpatient CDR with inpatient CDR. Our study will help surgeons fully understand the complications and safety profile surrounding outpatient CDR. OSF REGISTRATION NUMBER:: doi.org/10.17605/OSF.IO/3597Z.

Comparison of cervical disc arthroplasty and anterior cervical discectomy and fusion for the treatment of cervical disc degenerative diseases on the basis of more than 60 months of follow-up: a systematic review and meta-analysis

BACKGROUND

This meta-analysis was designed to investigate the long-term efficacy and safety between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) in treating cervical disc degenerative diseases (CDDDs).

METHODS

Literature search was performed on Pubmed, Embase, Cochrane Library, and Web of Science before Jan 2019. Surgical details, clinical outcomes, range of motion (ROM), complications, and reoperation rates between CDA and ACDF groups were compared and analyzed. A fixed- or random-effects model was applied based on different heterogeneity. STATA (Version 11.0) software was used to perform data analysis.

RESULTS

A total of 13 randomized controlled trial studies with more than 60 months of follow-up (mean 83.1 months) were enrolled in this meta-analysis. Pool results indicated that the CDA group exhibited significantly better outcomes in clinical scores (odds ratio [OR] = 1.54, 95% confidence interval [CI]: 1.15-2.08, p = 0.004) and preservation of ROM (mean difference = 1.77, 95% CI: 1.60-1.95, p < 0.001) than the ACDF group. Meanwhile, the incidence of adjacent segment disease (ASD) (OR = 0.51, 95% CI: 0.35-0.76, p = 0.001) and occurrence of reoperation (OR = 0.41, 95% CI: 0.25-0.69, p = 0.001) were lower in the CDA group than in the ACDF group.

CONCLUSIONS

At long-term follow-up, CDA showed better efficacy in terms of clinical outcomes, ROM, ASD, and reoperation than ACDF for treating CDDDs. However, our results require further validation in large-sample and high-quality studies.

Long-Term Effect of Diabetes on Reoperation After Lumbar Spinal Surgery: A Nationwide Population-Based Sample Cohort Study

BACKGROUND

Diabetes mellitus (DM) is associated with poor postoperative outcomes and increased morbidity after surgeries. Some previous studies have addressed the close association between DM and those leading to reoperations, whereas others have rejected this theory. This study aimed to evaluate the long-term effect of DM on lumbar spinal surgery using data from a nationwide sample cohort.

METHODS

A population-based cohort comprised one million people, which is a 2.1% representative sample of the Korean population. The present study included adult patients with lumbar degenerative diseases (e.g., lumbar spinal stenosis and spondylolisthesis), who underwent their first lumbar surgery in 2006. The cumulative incidence function for reoperation was calculated and multivariate analysis was performed to define correlation between reoperation and independent factors.

RESULTS

A total of 2020 patients were enrolled and followed up for 10 years. Nondiabetic patients, patients with DM without complication (DwoC), and patients with DM with complication (DwC) accounted for 79.5%, 9.36%, and 11.14% of all patients, respectively. Reoperation incidence stratified by DM was 12.7% for nondiabetic patients, 22.2% for patients with DwoC, and 20.0% for patients with DwC in 10 years of follow-up. During the same period, death, a competing event of reoperation, occurred in 7.8% of nondiabetic patients, in 13.2% of patients with DwoC, and in 20.9% of patients with DwC.

CONCLUSIONS

DM increased 1.65 times the overall cumulative incidences of reoperation after lumbar spinal surgeries for 10 years of follow-up. The reoperation incidence for DwC may be lower than that for DwoC because of a high incidence of death as a competing event of reoperation.

Future endeavors in ambulatory spine surgery

Due to the high societal and financial burden of spinal disorders, spine surgery is thought to be one of the most impactful targets for healthcare cost reduction. One avenue for cost-reduction that is increasingly being explored not just in spine surgery but across specialties is the performance of surgeries in ambulatory surgery centers (ASCs). Despite potential cost-savings, the utilization of ASCs for spine surgery remains largely limited to high-volume centers in the US, and predominantly for single- or two-level lumbar microdiscectomy and anterior cervical discectomy and fusion (ACDF) procedures. Factors most commonly cited for the lack of wider adoption include the risk of life-threatening complications, paucity of guidelines, and limited accessibility of these procedures to various patient populations. Thus, the future growth and adoption of ambulatory spine surgery depends on addressing these concerns by developing evidence-based guidelines for patient- and procedure selection, creating risk-stratification tools, devising appropriate discharge recommendations, and optimizing care protocols to ensure that safety, efficacy and outcomes are maintained. Other avenues that may allow for more widespread use of ASCs include the use of electronic health tools for post-operative monitoring after discharge from the ASC, increasing accessibility of ambulatory procedures to eligible populations, and identifying systemic inefficiencies and implementing process-improvement measures to optimize patient-selection, scheduling and peri-operative management. The success of ambulatory surgery ultimately depends not only on the surgical procedure, but also on its organization upstream and downstream. It provides an exciting and burgeoning avenue for innovation, cost-reduction and value-creation.