Effects of Body Mass Index on Perioperative Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgery

Cervical disc arthroplasty is safe across various obesity levels

BACKGROUND CONTEXT

As surgical indications for cervical disc arthroplasty (CDA) continue to expand, a growing patient population is now becoming indicated for this procedure. Little is known about whether CDA is safe in the overweight and obese populations, and how this procedure compares to anterior cervical discectomy and fusion (ACDF) in this particular demographic.

PURPOSE

To evaluate the outcomes of CDA across varying levels of body mass indices and to compare these to ACDF.

DESIGN

Retrospective cohort study.

PATIENT SAMPLE

A total of 12,454 patients who underwent CDA and 45,513 patients who underwent ACDF between 2011 and 2020 were included in this study.

OUTCOME MEASURES

The following data were observed for all cases: patient demographics, complications, revisions.

METHODS

The PearlDiver database was queried to identify all adults who underwent single-level CDA. Patients were stratified by body mass index (BMI), defined as Healthy Weight (<25kg/m2), Overweight (25-30kg/m2), Obese (30-40kg/m2), and Morbidly Obese (>40kg/m2). Patient demographics and comorbidities were compared before matching, and medical and surgical complications were compared after matching for age, sex, and Charlson Comorbidity Index (CCI). Similar comparative analyses were performed on all obese patients (>30kgm/2) who underwent single-level CDA and single-level ACDF.

RESULTS

In total, 1907 Healthy Weight, 3295 Overweight, 5431 Obese, and 1821 Morbidly Obese patients were included. The mean age was between 45.43 and 47.41 years, 57.12% and 71.68% were female, and mean CCI was 1.16-1.73 across groups (all p<.001). Mean CCI (Healthy Weight=1.16, Overweight=1.31, Obese=1.47, Morbidly Obese=1.63) and rate of comorbidities, such as diabetes (19.19%, 25.74%, 37.51%, 48.65%), hypertension (45.20%, 56.18%, 69.21%, 76.22%), and hyperlipidemia (49.34%, 60.61%, 65.33%, 64.96%), generally increased with increasing BMI (p<.001). After matching, mean age was 44.59 years, 70.98% were female, and mean CCI was 1.07 for all groups. At 90 days postoperatively, medical complications, including infection, wound dehiscence, and readmissions, were comparable (p>.05). At 2 years postoperatively, anterior revision was higher in Healthy Weight patients (30.27%, 28.11%, 24.71%, 24.96%, p=.005) but other surgical complications, including dysphagia, dysphonia, and implant failure, were otherwise comparable (p>.05). Comparison of all obese patients across cervical procedures revealed higher rates of 90-day emergency department visits (ACDF=21.56% vs 16.65%, p<.001) and 1-year hardware removal (1.49% vs 0.81%, p=.002), wound exploration (0.73% vs 0.35%, p=.018), and posterior fusion (1.14% vs 0.44%, p<.001) and lower rates of anterior revision (18.82% vs 23.68%, p<.001) in ACDF patients compared to CDA patients.

CONCLUSION

CDA may be safe across varying levels of obesity without any appreciable change in medical and surgical complications. In addition, single-level ACDF may result in higher complications than single-level CDA in the obese population.

The Effect of Patient Resilience on Postoperative Scores After One- and Two-Level Anterior Cervical Discectomy and Fusion

OBJECTIVE

To investigate the association between resilience and outcomes of pain and neck-related disability after single- and double-level anterior cervical discectomy and fusion (ACDF).

METHODS

Patients who underwent single- or double-level ACDF were sent a survey between 6 months and 2 years after surgery. The survey included the Brief Resilience Scale (BRS), visual analogue scale (VAS) for pain, Neck Disability Index (NDI), and Pain Self-Efficacy Questionnaire (PSEQ-2). Patients completed the VAS and NDI twice, once describing preoperative pain and disability and once describing current pain and disability. Respondents were classified as high resilience (HR), medium resilience (MR), or low resilience (LR). Demographics, PSEQ-2 scores, pre- and postoperative VAS and NDI scores, and change in VAS (ΔVAS) and NDI (ΔNDI) scores were compared between groups.

RESULTS

Thirty-three patients comprised the HR group, 273 patients comprised the MR group, and 47 patients comprised the LR group. All groups demonstrated postoperative improvement in VAS and NDI scores that exceeded previously established MCID values. The HR group demonstrated greater improvement in pain compared with the LR group (ΔVAS: -5.8 for HR vs. -4.4 for LR, P = 0.05). Compared with the MR group, the LR group demonstrated greater postoperative pain (VAS: 3.2 for LR vs. 2.5 for MR, P = 0.02) and disability (NDI: 11.9 for LR vs. 8.6 for MR, P = 0.02).

CONCLUSIONS

Patients demonstrated improvement in pain and neck-related disability after single- and double-level ACDF, regardless of resilience score. Patients with greater resilience may be expected to demonstrate more improvement in pain after ACDF.

Trends in Indications and Contraindications for Cervical Disk Arthroplasty from 2009 to 2019

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

Assess trends of indications and contraindications for the use of Cervical Disk Arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

As spine surgeons become more familiar with CDA, there have been expansions in indications.

METHODS

The Medicare Provider Analysis and Review Limited Data Sets for 2009, 2014, and 2019 were utilized. Patients undergoing elective CDA were included. Diagnosis for index surgery and "contraindications" as defined by original CDA Investigative Device Exemption (IDE) criteria were assessed. Variables were identified by the International Classification of Diseases (ICD)-9 or ICD-10 diagnosis and procedural codes.

RESULTS

A total of 1067 elective CDA patients were included. There were 230 patients in 2009, 300 patients in 2014, and 537 patients in 2019. The proportion of patients aged >65 increased from 35% to 51% ( P <0.001). Incidence of CDA for radiculopathy increased from 57% to 69% ( P <0.001), myelopathy increased from 23% to 78% ( P <0.001), and spondylosis without radiculopathy or myelopathy decreased from 19% to 3% ( P <0.001). There were increased incidences of ankylosing spondylitis (0.4% to 2.8%, P =0.007), long-term steroid use (1% to 2%, P =0.039), morbid obesity (2% to 6%, P =0.019), and osteoporosis (1% to 5%, P =0.014). The incidence of hybrid CDA and anterior cervical discectomy and fusion (ACDF) decreased from 28% to 23% ( P =0.007).

CONCLUSION

From 2009 to 2019, the number of CDA performed in older patients increased. An increase in the use of CDA for the treatment of myelopathy and radiculopathy and a decrease in the treatment of isolated cervical spondylosis was observed. The proportion of CDA performed in patients with original IDE trial "contraindications" increased. Further research into the efficacy of CDA for patients with contraindications is warranted.

Disability and pain after anterior cervical decompression and fusion: A group-based trajectory analysis

OBJECTIVES

This study aimed to identify the clusters of patients with different developmental trajectories of pain and disability after anterior cervical decompression and fusion (ACDF).

METHODS

Group-based trajectory analysis among 318 patients undergoing the ACDF.

RESULTS

Three developmental trajectories of disability were identified: "Steadily good functioning," "Improved functioning," and "Steadily poor functioning." Three developmental trajectories of neck pain were identified: "Worsened pain," "Pain relief," and "Steadily severe pain." Two developmental trajectories of arm pain were identified: "Decreased arm pain" and "Severe arm pain with only short-term relief." No associations were found between sex, preoperative pain duration, or body weight and probability to be classified into a particular disability trajectory group. Female sex (relative risk ratio (RRR) 1.78) and longer history of preoperative pain (RRR 2.31-2.68) increased the probability to be classified into a group with steadily severe neck pain. Longer history of preoperative pain increased the probability to be classified into group with severe arm pain with only short-term pain relief (RRR 2.68).

CONCLUSION

After the ACDF, dissimilar developmental trajectories of pain and disability were identified between the patient clusters. While sex, preoperative pain duration, and body weight were not associated with differences in improvement in disability level, female sex and longer duration of preoperative pain were correlated with more severe neck and arm pain after surgery.

The Effect of the Coronavirus Disease 2019 Pandemic on Pituitary Surgery

OBJECTIVE

As the coronavirus disease 2019 (COVID-19) pandemic spread to the United States in 2020, there was an impetus toward postponing or ceasing nonurgent transsphenoidal pituitary surgeries to prevent the spread of the virus. Some centers encouraged transcranial approaches for patients with declining neurologic function. However, no large-scale data exist evaluating the effects that this situation had on national pituitary practice patterns.

METHODS

Pituitary surgeries in the National Inpatient Sample were identified from 2017 to 2020. Surgeries in 2020 were compared with the 3 years previously to determine any differences in demographics, surgical trends/approaches, and perioperative outcomes.

RESULTS

In 2020, there was a decline in overall pituitary surgeries (34.2 vs. 36.3%; odds ratio (OR), 0.88; P < 0.001) yet transsphenoidal approaches represented a higher proportion of interventions (69.0 vs. 64.9%; P < 0.001). Neurosurgical complications were higher (51.9 vs. 47.4%; OR, 1.13; P < 0.001) and patients were less likely to be discharged home (86.4 vs. 88.5%; OR, 0.84; P < 0.001). This finding was especially true in April 2020 during the first peak in COVID-19 cases, when transcranial approaches and odds of mortality/complications were highest.

CONCLUSIONS

In 2020, transsphenoidal surgery remained the preferred approach for pituitary tumor resection despite initial recommendations against the approach to prevent COVID-19 spread. Pituitary surgeries had a higher risk of periprocedural complications despite accounting for preoperative comorbidities, COVID-19 infection status, and surgical approach, suggesting that an overwhelmed hospital system can negatively influence surgical outcomes in noninfected patients.

Effects of Obesity on Cervical Disc Arthroplasty Complications

OBJECTIVE

High body mass index is a well-established modifiable comorbidity that is known to increase postoperative complications in all types of surgery, including spine surgery. Obesity is increasing in prevalence amongst the general population. As this growing population of obese patients ages, understanding how they faire undergoing cervical disc arthroplasty (CDA) is important for providing safe and effective evidence-based care for cervical degenerative pathology.

METHODS

Our study used the Healthcare Cost and Utilization Project's National Inpatient Sample to assess patients undergoing CDA comparing patient characteristics and outcomes in nonobese patients to obese patients from 2004 to 2014.

RESULTS

Our study found a significant increase in the overall utilization of CDA as a treatment modality (p = 0.012) and a statistically significant increase in obese patients undergoing CDA (p < 0.0001) from 2004 to 2014. Obesity was identified as an independent risk factor associated with increased rates of inpatient neurologic complications (odds ratio [OR], 6.99; p = 0.03), pulmonary embolus (OR, 5.41; p = 0.05), and wound infection (OR, 6.97; p < 0.001) in patients undergoing CDA from 2004 to 2014.

CONCLUSION

In patients undergoing CDA, from 2004 to 2014, obesity was identified as an independent risk factor with significantly increased rates of inpatient neurologic complications, pulmonary embolus and wound infection. Large prospective trials are needed to validate these findings.

Enhanced Intervertebral Disc Repair via Genetically Engineered Mesenchymal Stem Cells with Tetracycline Regulatory System

The therapeutic potential of Mesenchymal stem cells (MSCs) for the treatment of Intervertebral disc (IVD) degeneration can be enhanced by amplifying specific cytokines and proteins. This study aimed to investigate the therapeutic potential of tetracycline-off system-engineered tonsil-derived mesenchymal stem cells (ToMSC-Tetoff-TGFβ1-IGF1-BMP7) for treating intervertebral disc (IVD) degeneration. ToMSCs were isolated from a tonsillectomy patient and genetically modified with four distinct plasmids via CRISPR/Cas9-mediated knock-in gene editing. Transgene expression was confirmed through immunofluorescence, western blots, and an enzyme-linked immunosorbent assay for transforming growth factor beta 1 (TGFβ1) protein secretion, and the effect of MSC-TetOff-TGFβ1-IGF1-BMP7 on disc injury was assessed in a rat model. The ToMSC-Tetoff-TGFβ1-IGF1-BMP7 treatment exhibited superior therapeutic effects compared to ToMSC-TGFβ1, and ToMSC-SDF1α implantation groups, stimulating the regeneration of nucleus pulposus (NP) cells crucial for IVD. The treatment showed potential to restore the structural integrity of the extracellular matrix (ECM) by upregulating key molecules such as aggrecan and type II collagen. It also exhibited anti-inflammatory properties and reduced pain-inducing neuropeptides. ToMSC-Tetoff-TGFβ1-IGF1-BMP7 holds promise as a novel treatment for IVD degeneration. It appears to promote NP cell regeneration, restore ECM structure, suppress inflammation, and reduce pain. However, more research and clinical trials are required to confirm its therapeutic potential.

Severe Obesity Is an Independent Risk Factor of Early Readmission and Nonhome Discharge After Cervical Disc Replacement

OBJECTIVE

Despite growing interest in cervical disc replacement (CDR) for conditions such as cervical radiculopathy, limited data exists describing the impact of obesity on early postoperative outcomes and complications. These data are especially important as nearly half of the adult population in the United States is expected to become obese (body mass index [BMI] ≥ 30 kg/m2) by 2030. The goal of this study was to compare the demographics, perioperative variables, and complication rates following CDR.

METHODS

The 2005-2020 American College of Surgeons National Surgical Quality Improvement Program datasets were queried for patients who underwent primary 1- or 2-level CDR. Patients were divided into 3 cohorts: Nonobese (BMI: 18.5-29.9 kg/m2), Obese class-I (BMI: 30-34.9 kg/m2), Obese class-II/III (BMI ≥ 35 kg/m2). Morbidity was defined as the presence of any complication within 30 days postoperatively. Rates of 30-day readmission, reoperation, morbidity, individual complications, length of stay, frequency of nonhome discharge disposition were collected.

RESULTS

A total of 5,397 patients were included for analysis: 3,130 were nonobese, 1,348 were obese class I, and 919 were obese class II/III. There were more 2-level CDRs performed in the class II/III cohort compared to the nonobese group (25.7% vs. 21.5%, respectively; p < 0.05). Class-II/III had more nonhome discharges than class I and nonobese (2.1% vs. 0.5% vs. 0.7%, respectively; p < 0.001). Readmission rates differed as well (nonobese: 0.5%, class I: 1.1%, class II/III: 2.1%; p < 0.001) with pairwise significance between class II/II and nonobese. Class II/III obesity was an independent risk factor for both readmission (odds ratio [OR], 3.32; p = 0.002) and nonhome discharge (OR, 2.51; p = 0.02). Neither 30-day reoperation nor morbidity rates demonstrated significance. No mortalities were reported.

CONCLUSION

Although obese class-II/III were risk factors for 30-day readmission and nonhome discharge, there was no significant difference in reoperation rates or morbidity. CDR procedures can continue to be safely preformed independent of obesity status.

Morbid Obesity Increases Length of Surgery in Elective Anterior Cervical Discectomy and Fusion Procedures but Not Readmission or Reoperation Rates: A Cohort Study

BACKGROUND

As the obesity epidemic grows, the number of morbidly obese patients undergoing anterior cervical discectomy and fusion (ACDF) continues to increase. Despite the association of obesity with perioperative complications in anterior cervical surgery, the impact of morbid obesity on ACDF complications remains controversial, and studies examining morbidly obese cohorts are limited.

METHODS

A single-institution, retrospective analysis of patients undergoing ACDF from September 2010 to February 2022 was performed. Demographic, intraoperative, and postoperative data were collected via review of the electronic medical record. Patients were categorized as nonobese (body mass index [BMI] <30), obese (BMI 30-39.9), or morbidly obese (BMI ≥40). Associations of BMI class with discharge disposition, length of surgery, and length of stay were assessed using multivariable logistic regression, multivariable linear regression, and negative binomial regression, respectively.

RESULTS

The study included 670 patients undergoing single-level or multilevel ACDF: 413 (61.6%) nonobese, 226 (33.7%) obese, and 31 (4.6%) morbidly obese patients. BMI class was associated with prior history of deep venous thrombosis (P < 0.01), pulmonary thromboembolism (P < 0.05), and diabetes mellitus (P < 0.001). In bivariate analysis, there was no significant association between BMI class and reoperation or readmission rates at 30, 60, or 365 days postoperatively. In multivariable analysis, greater BMI class was associated with increased length of surgery (P = 0.03), but not length of stay or discharge disposition.

CONCLUSIONS

For patients undergoing ACDF, greater BMI class was associated with increased length of surgery, but not reoperation rate, readmission rate, length of stay, or discharge disposition.

Leveraging HFRS to assess how frailty affects healthcare resource utilization after elective ACDF for CSM

BACKGROUND CONTEXT

Frailty is a common comorbidity associated with worsening outcomes in various medical and surgical fields. The Hospital Frailty Risk Score (HFRS) is a recently developed tool which assesses frailty using 109 International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) comorbidity codes to assess severity of frailty. However, there is a paucity of studies utilizing the HFRS with patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM).

PURPOSE

The aim of this study was to investigate the impact of HFRS on health care resource utilization following ACDF for CSM.

STUDY DESIGN

A retrospective cohort study was performed using the Nationwide Inpatient Sample (NIS) database from 2016-2019.

PATIENT SAMPLE

All adult (≥18 years old) patients undergoing primary, ACDF for CSM were identified using the ICD-10 CM codes.

OUTCOME MEASURES

Weighted patient demographics, comorbidities, perioperative complications, LOS, discharge disposition, and total admission costs were assessed.

METHODS

The 109 ICD-10 codes with pre-assigned values from 0.1 to 7.1 pertaining to frailty were queried in each patient, with a cumulative HFRS ≥5 indicating a frail patient. Patients were then categorized as either Low HFRS (HFRS<5) or Moderate to High HFRS (HFRS≥5). A multivariate stepwise logistic regression was used to determine the odds ratio for risk-adjusted extended LOS, non-routine discharge disposition, and increased hospital cost.

RESULTS

A total of 29,305 patients were identified, of which 3,135 (10.7%) had a Moderate to High HFRS. Patients with a Moderate to High HFRS had higher rates of 1 or more postoperative complications (Low HFRS: 9.5% vs. Moderate-High HFRS: 38.6%, p≤.001), significantly longer hospital stays (Low HFRS: 1.8±1.7 days vs. Moderate-High HFRS: 4.4 ± 6.0, p≤.001), higher rates of non-routine discharge (Low HFRS: 5.8% vs. Moderate-High HFRS: 28.2%, p≤.001), and increased total cost of admission (Low HFRS: $19,691±9,740 vs. Moderate-High HFRS: $26,935±22,824, p≤.001) than patients in the Low HFRS cohort. On multivariate analysis, Moderate to High HFRS was found to be a significant independent predictor for extended LOS [OR: 3.19, 95% CI: (2.60, 3.91), p≤.001] and non-routine discharge disposition [OR: 3.88, 95% CI: (3.05, 4.95), p≤.001] but not increased cost [OR: 1.10, 95% CI: (0.87, 1.40), p=.418].

CONCLUSIONS

Our study suggests that patients with a higher HFRS have increased total hospital costs, a longer LOS, higher complication rates, and more frequent nonroutine discharge compared with patients with a low HFRS following elective ACDF for CSM. Although frail patients should not be precluded from surgical management of cervical spine pathology, these findings highlight the need for peri-operative protocols to medically optimize patients to improve health care quality and decrease costs.

The Effect of Diabetes and Metabolic Syndrome on Spine Surgery Outcomes

PURPOSE OF REVIEW

Diabetes and metabolic syndrome are highly prevalent in patients undergoing spine surgery. This review aims to capture both the findings of recently published literature investigating the effects of diabetes and metabolic syndrome on spine surgery outcomes and the current best practices in patient management.

RECENT FINDINGS

Diabetes and metabolic syndrome both contribute to worse outcomes in patients undergoing spine surgery. Although patients with diabetes are at greater risk of complications, those with uncontrolled diabetes experience increased healthcare costs and greater odds of postoperative complications. Furthermore, metabolic syndrome is repeatedly shown to have an adverse effect on spine surgery outcomes, including healthcare costs and medical complications. Spine surgeons should coordinate care with primary care physicians to optimize the preoperative profile of patients with comorbidities like diabetes and metabolic syndrome to minimize operative risk. With the shift to value-based care, understanding the patient factors that lead to complications is becoming increasingly important. Future studies should build upon the current literature and design preoperative interventions for at-risk patients. Additionally, further research is needed to analyze the modulatory effects of the social determinants of health in patients with diabetes and metabolic syndrome.

Cervical Radiculopathy: Focus on Factors for Better Surgical Outcomes and Operative Techniques

For patients with cervical radiculopathy, most studies have recommended conservative treatment as the first-line treatment; however, when conventional treatment fails, surgery is considered. A better understanding of the prognosis of cervical radiculopathy is essential to provide accurate information to the patients. If the patients complain of persistent and recurrent arm pain/numbness not respond to conservative treatment, or exhibit neurologic deficits, surgery is performed using anterior or posterior approaches. Anterior cervical discectomy and fusion (ACDF) has historically been widely used and has proven to be safe and effective. To improve surgical outcomes of ACDF surgery, many studies have been conducted on types of spacers, size/height/position of cages, anterior plating, patients' factors, surgical techniques, and so forth. Cervical disc replacement (CDR) is designed to reduce the incidence of adjacent segment disease during long-term follow-up by maintaining cervical spine motion postoperatively. Many studies on excellent indications for the CDR, proper type/size/shape/height of the implants, and surgical techniques were performed. Posterior cervical foraminotomy is a safe and effective surgical option to avoid complications associated with anterior approach and fusion surgery. Most recent literature demonstrated that all three surgical techniques for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice the operative techniques for patients with cervical radiculopathy.

Increased risk of postoperative wound complications among obesity classes II & III after ALIF in 10-year ACS-NSQIP analysis of 10,934 cases

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) procedures for lumbar spine disease have been increasing amid a growing obese patient population with limited studies available focusing exclusively on risk-factors for post-operative ALIF complications.

PURPOSE

The objective of this study was to compare 30-day post-operative complications among different obesity World Health Organization classes according to body mass index (BMI) in comparison to non-obese patients who underwent an ALIF procedure.

STUDY DESIGN/SETTING

Retrospective cohort study of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2009 to 2019.

PATIENT SAMPLE

A total of 10,934 patients undergoing an ALIF.

OUTCOME MEASURES

Primary outcome measures include 30 day cardiac, pulmonary, urinary, infectious, and wound complications. Secondary outcomes included rates of blood transfusion, reintubation, deep vein thrombosis, pulmonary embolism, 30-day return to the operating room (OR), and 30 day mortality.

METHODS

Patients were identified by use of the current procedural terminology codes 22558 and 22585 from 2009 to 2019. Patients were divided into the following groups: non-obese (BMI 18.5-29.9 kg/m²), Obese I (BMI 30-34.9 kg/m²), Obese II (BMI 35-39.9 kg/m²), and Obese III (BMI ≥40 kg/m²). Age, gender, race, American Society of Anesthesiologists status, smoking status, hypertension requiring medication, steroid used, chronic obstructive pulmonary disease, history of a bleeding disorder, and diabetes was identified as risk factors after a univariate analysis conducted for demographic variables and pre-operative comorbidities. A multivariate logistic regression analysis was then performed to adjust for these preoperative risk factors and compare obesity classes I-III to non-obese patients.

RESULTS

Obesity classes II and III had a significant odds ratio (OR) for superficial infection (OR:2.7, 95%CI(1.7-4.5); OR:2.8, 95%CI(1.5-5.2) respectively), organ space infection (OR:3.8, 95%CI(1.6-7.4); OR:3.2, 95%CI(1.1-9.9) respectively), wound disruption (OR:2.8, 95%CI(1.1-7.4); OR:4.6, 95%CI(1.6-13.6) respectively), and total wound complication (OR:2.6, 95%CI(1.8-3.9); OR:3.4, 95%CI(2.2-5.4) respectively) following a multivariate logistic regression analysis.

CONCLUSIONS

Risk for post-operative wound complications following an ALIF were found to be significantly higher for obesity classes II-III in comparison to non-obese patients. These findings can further support the use of additional wound care in the perioperative setting for certain levels of obesity.

Incidence and Clinical Outcomes of Hypothyroidism in Patients Undergoing Spinal Fusion

Background

Hypothyroidism has been independently associated with the development of several comorbidities and is known to increase complication rates in non-spinal surgeries. However, there are limited data regarding the effects of hypothyroidism in major spine surgery. Therefore, we present the largest retrospective analysis evaluating outcomes in hypothyroid patients undergoing spinal fusion.

Methods

A retrospective review of the National Inpatient Sample (NIS) from 2004-2014 was performed. Patients with an International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) procedure code indicating spinal fusion (81.04-81.08, 81.34-81.38, 81.0x, 81.3x) were included. Patients with an ICD-9-CM diagnosis code indicating hypothyroidism (244.x) were compared to those without. Cervical and lumbar fusions were evaluated independently. Significant covariates in univariable logistic regression were utilized to construct multivariable models to analyze the effect of hypothyroidism on perioperative morbidity and mortality.

Results

A total of 4,149,125 patients were identified, of which 9.4% were hypothyroid. Although, hypothyroid patients had a higher risk of hematologic complications (lumbar - odds ratio [OR] 1.176, p < 0.0001; cervical - OR 1.162, p < 0.0001), they exhibited decreased in-hospital mortality (lumbar - OR .643, p < 0.0001; cervical - OR .606, p < 0.0001). Hypothyroid lumbar fusion patients also demonstrated decreased rates of perioperative myocardial infarction (MI) (OR .851, p < 0.0001). All these results were independent of patient gender.

Conclusions

Hypothyroid patients undergoing spinal fusion demonstrated lower rates of inpatient mortality and, in lumbar fusions, also had lower rates of acute MI when compared to their euthyroid counterparts. This suggests that hypothyroidism may offer protection against all-cause mortality and may be cardioprotective in the postoperative period for lumbar spinal fusions independent of patient gender.

Independent Association of Obesity and Nonroutine Discharge Disposition After Elective Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Myelopathy

OBJECTIVE

The prevalence of obesity continues to rise in the United States at a disparaging rate. Although previous studies have attempted to identify the influence obesity has on short-term outcomes following elective spine surgery, few studies have assessed the impact on discharge disposition following anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). The aim of this study was to determine whether obesity impacts the hospital management, cost, and discharge disposition after elective ACDF for adult CSM.

METHODS

The National Inpatient Sample database was queried using the International Classification of Diseases, 10th revision, Clinical Modification, coding system to identify all (≥18 years) patients with a primary diagnosis of CSM undergoing an elective ACDF for the years 2016 and 2017. Discharge weights were used to estimate national demographics, Elixhauser comorbidities, complications, length of stay, total cost of admission, and discharge disposition.

RESULTS

There were 17,385 patients included in the study, of whom 3035 (17.4%) had obesity (no obesity: 14,350; obesity: 3035). The cohort with obesity had a significantly greater proportion of patients with 3 or more comorbidities compared with the cohort with no obesity (no obesity: 28.1% vs. obesity: 43.5%, P < 0.001). The overall complication rates were greater in the cohort with obesity (no obesity: 10.3% vs. obesity: 14.3%, P = 0.003). On average, the cohort with obesity incurred a total cost of admission $1154 greater than the cost of the cohort with no obesity (no obesity: $19,732 ± 11,605 vs. obesity: $20,886 ± 10,883, P = 0.034) and a significantly greater proportion of nonroutine discharges (no obesity: 16.6% vs. obesity: 24.2%, P < 0.001). In multivariate regression analysis, obesity, age, race, health care coverage, hospital bed size, region, comorbidity, and complication rates all were independently associated with nonroutine discharge disposition.

CONCLUSIONS

Our study demonstrates that obesity is an independent predictor for nonroutine discharge disposition following elective anterior cervical discectomy and fusion for cervical spondylotic myelopathy.

National Trends and Correlates of Dysphagia After Anterior Cervical Discectomy and Fusion Surgery

Objective

Anterior cervical discectomy and fusion (ACDF) is the most common performed surgery in the cervical spine. Dysphagia is one of the most frequent complications following ACDF. Several studies have identified certain demographic and perioperative risk factors associated with increased dysphagia rates, but few have reported recent trends. Our study aims to report current trends and factors associated with the development of inpatient postoperative dysphagia after ACDF.

Methods

The National Inpatient Sample was evaluated from 2004 to 2014 and discharges with International Classification of Diseases procedure codes indicating ACDF were selected. Time trend series plots were created for the yearly treatment trends for each fusion level by dysphagia outcome. Separate univariable followed by multivariable logistic regression analyses were performed to evaluate predictors of dysphagia.

Results

A total of 1,212,475 ACDFs were identified in which 3.3% experienced postoperative dysphagia. A significant increase in annual dysphagia rates was observed from 2004–2014. Frailty, intraoperative neuromonitoring, 4 or more level fusions, African American race, fluid/electrolyte disorders, blood loss, and coagulopathy were all identified as significant independent risk factors for the development of postoperative dysphagia following ACDF.

Conclusion

Postoperative dysphagia is a well-known postsurgical complication associated with ACDF. Our cohort showed a significant increase in the annual dysphagia rates independent of levels fused. We identified several risk factors associated with the development of postoperative dysphagia after ACDF.