United States

Introduction. Postoperative pain control is critical in orthopedic surgery. While efficacious analgesics, opiates have rapid tolerance and addictive potential. Metamizole is a non-opioid analgesic primarily inhibiting COX-3, commonly used in Europe and South America, but banned in the U.S. due to concerns about agranulocytosis risk. However, large meta-analyses have not shown significant agranulocytosis when compared to other analgesics. The purpose of this review is to assess the analgesic efficacy of metamizole and potential use in orthopedic surgery.
Methods. An electronic review was conducted of PubMed, Web of Science, Cochrane, Embase, and OVID Medline in October 2023. Studies for inclusion were limited to those in which metamizole use was a primary focus, patients were undergoing orthopedic surgery, studies in human patients, and studies reporting in the English language.
Results. 1,112 studies were identified and 15 (1.3%) met inclusion criteria. The use of metamizole as a single agent or in combination therapy was described to be superior or non-inferior to alternative analgesics in 10 (66.7%) studies. Metamizole decreased rescue analgesia in 5 (33.3%) articles. No patients experienced agranulocytosis.
Conclusions. Metamizole was efficaciously non-inferior to other non-opioid analgesics by demonstrating an opioid sparing effect in over a third of included studies. Metamizole did not have significant differences in incidence or severity of side effects and no cases of agranulocytosis were seen across all studies. These results indicate the potential for metamizole as analgesia in the setting of orthopedic surgery. Future studies should focus on larger cohorts to continue to assess efficacy and risk of agranulocytosis.


AMA Research Challenge 2024 

Postoperative Pain Management with Metamizole after Orthopedic Surgery: A Systematic Review

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Background
Congenital cervical stenosis (CCS) is a rare condition involving a narrowed spinal canal due to developmental anomalies. CCS heightens the risk of neurologic deficits and acute spinal cord injury post-trauma, influencing return-to-play decisions for contact athletes. Additionally, CCS patients are prone to cervical myelopathy as degenerative changes progress with age. Limited evidence-based literature exists on the epidemiology of CCS, including racial effects. We sought to investigate the incidence of CCS as it pertains to race and ethnicity.
Methods
We screened 5395 cervical MRIs from a single institution and identified CCS by a sagittal canal diameter (SCD) of less than 10 mm at 2 or more vertebral levels (C3-7) at the pedicle. Exclusion criteria included patients under 18 and over 50 years, prior cervical spine surgery, congenital fusions, spinal column malignancy, or active smoking history. For each patient, axial measurements were taken at each level, including coronal vertebral body length, anteroposterior vertebral body length, pedicle width, pedicle length, laminar length, anteroposterior lateral mass length, posterior canal distance, apex-to-vertebral body, lamina-disc angle (LDA), lamina-pedicle angle, and anteroposterior spinal cord diameter.
Results
A total of 343 patients met the criteria for CCS: 100 White, 98 Black, 70 Asian, and 75 Hispanic. CCS prevalence varied significantly among ethnic groups; Black (39.3%), Asian (33.6%), and Hispanic (22%) patients had higher CCS rates than White patients (7.5%) [x2 (3, N=343) = 30.04, p <0.05]. The Interrater Correlation Coefficient for the SCD measurements across all levels and patients demonstrated excellent reliability (ICC = 0.926, 95% CI: 0.91-0.94). Black and Asian patients showed consistently smaller SCDs at all pedicle levels compared to White patients, who had the largest SCDs overall (p<0.001). Average SCDs were 11.4 mm (White), 10.4 mm (Black), 10.5 mm (Asian), and 11 mm (Hispanic). Additionally, LDAs were larger in Asians, Blacks, and Hispanics compared to Whites, reducing cross-sectional canal area (p<0.001).
Conclusion
Our study indicates a significant correlation between race/ethnicity and CCS prevalence. Black and Asian patients had the highest CCS rates, smallest SCDs, and largest LDAs. These anatomical differences suggest an increased risk of cervical myelopathy and neurological issues, particularly for contact sport athletes. This emphasizes the need for personalized clinical management and early intervention to address healthcare disparities and improve outcomes in vulnerable populations.


Racial Differences in Congenital Cervical Stenosis

ABSTRACT

Background: Midshaft clavicle fractures are often subject to increased complications when treated nonoperatively, so surgical treatment with open reduction and internal fixation (ORIF) is a favored alternative. Despite safer outcomes, adverse events such as surgical site infections may still persist, particularly in the presence of certain patient characteristics. The objective of this study was to determine risk factors for and the frequency of adverse events following ORIF for clavicle fractures. 

Methods: A retrospective review of the National Surgical Quality Improvement Program (NSQIP) database from 2012 to 2021 identified patients undergoing isolated ORIF for clavicle fractures. Patient demographics and 30-day complications were collected. Bivariate analyses with a student’s t-test or chi-square test were used to identify possible predictor variables for either AAE or SSI, and demographic metrics with P<0.2 were included in a multivariable regression model. Multivariable analyses identified significant independent patient risk factors for any adverse event (AAE) or SSI within 30-days of surgery. Adjusted odds ratios were reported for each variable included in the model. Statistical significance was set a prior at P<0.05.

Results: The 6,753 selected patients who underwent ORIF for clavicle fractures between 2012 and 2021 were 38.1±15.3 years of age, BMI 26.2±4.9 kg/m2, and 77.3% male. Of this cohort, 88.4% received treatment on an outpatient basis. Postoperative adverse events were experienced by 128 (1.9%) patients within 30 days of surgery, and SSI were prevalent in 0.77% of patients, followed by wound dehiscence in 0.12% of patients. After controlling for patient demographics and comorbidities, notable risk factors for adverse events included current smoking status (OR=2.036; P<0.001) and patient age (OR=1.025; P<0.001). Outpatient status (OR=0.528; P=0.004) was protective. 

Conclusion: The present study noted significantly increased risk of postoperative adverse events in older patients, as well as patients who smoke. Outpatient setting was significantly protective for adverse events. These findings help to provide further clinical context to guide surgical decision making and inform surgeons on current risks and outcomes.

Risk Factors for Adverse Events after Clavicle Fracture Open Reduction and Internal Fixation: A NSQIP Study

Title: 
Subsequent Total Shoulder Arthroplasty Following Common Shoulder Stabilization and Reconstructive Procedures

Background:
Shoulder stabilization and reconstructive surgeries are indicated based on a variety of pathologies including instability, impingement, and rotator cuff tears. Surgery to restore anatomic and biomechanical normalcy may reduce pain, restore function, or may slow the progression of osteoarthritis. This study analyzes common shoulder stabilization and reconstructive surgeries and compares their odds of future total shoulder arthroplasty (TSA) development.

Methods:
The TriNetX database patient data was queried from the period of May 2004 to May 2024 using ICD10 and CPT codes. Cohorts were built by including patients who underwent a procedure of interest, while the control group used a combination of patients from other procedural cohorts not undergoing the procedure of interest. Cohorts were then propensity matched for age, race, sex, and co-morbidities. Laterality was assessed separately to ensure ipsilateral index procedure and TSA. The primary outcome measured was TSA at 5 and 10 years postoperatively for 13 different shoulder procedures.


Results:
A total of 355,960 patients were divided into procedural cohorts and analyzed. The procedure with the highest rate of subsequent TSA was the Latarjet procedure (3.99% at 5 years; 4.23% at 10 years); whereas the procedure with the lowest rate was arthroscopic capsulorrhaphy (0.91% at 5 years; 0.95% at 10 years. Compared to propensity-matched controls, procedures associated with increased odds of subsequent TSA were the Latarjet procedure (OR 3.34, P<0.0001 at 5 years; OR 3.56, P<0.0001 at 10 years), arthroscopic capsulorrhaphy (OR 1.47, P=0.0042 at 5 years; OR 1.43, P=0.0066 at 10 years), open rotator cuff repair, chronic (OR 1.39, P=0.0005 at 5 years), arthroscopic extensive debridement (OR 1.31, P<0.0001 at 5 years; OR 1.26, P<0.0001 at 10 years), and open biceps tenodesis (OR 1.28, P=0.0003 at 5 years; OR 1.20, P=0.0053 at 10 years). Procedures associated with decreased odds of subsequent TSA were arthroscopic distal clavicle resection (OR 0.56, P<0.0001 at 5 years; OR 0.56, P<0.0001 at 10 years), arthroscopic subacromial decompression (OR 0.65, P<0.0001 at 5 years; OR 0.63, P<0.0001 at 10 years), arthroscopic rotator cuff repair (OR 0.78, P<0.0001 at 5 years; OR 74, P<0.0001 at 10 years), and arthroscopic biceps tenodesis (OR 0.78, P<0.0001 at 5 years; OR 0.76, P<0.0001 at 10 years).

Conclusion:
In general, arthroscopic procedures had decreased associated odds of subsequent TSA when compared to their open counterparts. However, arthroscopic capsulorrhaphy and arthroscopic extensive debridement had increased odds of subsequent TSA. The Latarjet procedure had the highest odds of all procedures for future TSA.


Subsequent Total Shoulder Arthroplasty Following Common Shoulder Stabilization and Reconstructive Procedures 


Background: Achilles tendon rupture is a common orthopedic injury presenting to the clinic and emergency room. Patients with comorbidities are not ideal surgical candidates and often must be treated with cast or boot immobilization. The risk of complications includes pressure sores, skin infections, and joint stiffness. Recently, 3D-printed (3DP) casting has become popular due to customizability and inexpensiveness. This study performs a systematic review on the clinical application of 3D-printed (3DP) for conservative management of injuries.

Methods: The search phrase “(3d printed cast) AND ((fracture) OR (injury) OR (tendon))” was entered into PubMed, yielding 50 results published between 2015 and 2024. 15 articles were included in this review.

Results: 3 studies showed proof-of-concept in a non-clinical setting for 3DP casting using biomechanical and materials testing in both UE and LE models. 5 clinical studies without a control group reported overall patient satisfaction and good to excellent clinical healing of UE fractures with 3DP but also reported incidents of cast breakage. 7 studies in a clinical setting showed that 3DP casting is superior to conventional fiberglass in patient satisfaction and non-inferior in clinical efficacy.

Discussion: Based on the current literature, this study proposes a novel 3D-printed cast that provides immobilization at the maximum plantar flexion required for Achilles tendon healing and eliminates the need for constant cast changes in a non-surgical treatment plan. The proposed device will act to maintain stability and reapproximation for healing at the injury site, whilst providing easy access for hygiene and wound care, thus mitigating the risk of infections and promoting optimal healing. Future direction will establish proof-of-concept using finite element analysis for customization of stress distribution and biomechanical testing for load-bearing analysis. By extending its usage to acute Achilles tendon injuries, 3DP casting has the potential to enhance outcomes for non-surgical candidates.

Systematic Review and Novel Proposal of 3D-Printed Casting for Non-Surgical Treatment of Acute Achilles Tendon Rupture

Background
Females and underrepresented in medicine (URiM) individuals currently comprise 50.5% and 23.8% of all medical student matriculates in the United States, respectively. However, orthopaedics remains the least diverse specialty with 18.3% female and 17.3% URiM residents. There has been an increasing amount of effort to increase diversity, equity, and inclusion (DEI) and remedy these representation gaps, however there remains a gap in the literature regarding the effectiveness of DEI initiatives at the medical student level and their impact on the future diversity of the orthopedic workforce. Thus, the purpose of this systematic review was to analyze the progress and current state of DEI efforts within orthopaedics at the medical student level.
Methods
A systematic review of the English literature was performed according to PRISMA guidelines using the following databases: PubMed, Web of Science, Embase, Scopus, Crochane from inception to October 20, 2023 using a combination of search terms. Eligible full text articles reported on various domains of DEI at the medical student level in the United States such as demographics, initiatives, and perspectives.
Results
A total of 3184 studies were screened and subsequently, 26 full-text articles met inclusion criteria. Eight articles discussed trends in diversity demographics within interest, application, and match with orthopaedics (30.8%), 10 articles discussed initiatives detailing methods and results of how to increase DEI in orthopaedics (38.4%), and 8 articles discussed perspectives on where to focus future outreach endeavors (30.8%).
Conclusion
Efforts to enhance female and URiM representation amongst orthopeadic residency programs at the medical student level have greatly improved over the past 15 years. Evidence shows a strong correlation between both the presence of underrepresented populations in faculty and resident positions as well as the implementation of outreach programs in influencing medical students' application into orthopeadic residency. A large majority of initiatives created for medical students stemmed from outside organizations as opposed to individual residency programs. Future studies should quantify the impact of local initiatives and national organizations on medical students and aim to better understand additional barriers into entrance of residency programs.

The Current State of DEI in Orthopaedics at the Medical Student Level; a Systematic Review

Background: Anterior Cruciate ligament reconstruction (ACLR) is one of the most common surgeries performed in orthopedics. The optimal timepoint for ACLR is not consistently defined. Our study aimed to address this gap by comparing patient-reported outcomes (PROs) in acute versus chronic ACLR groups using 60 days as a marker for chronicity. 



Methods: This historical cohort study was based on prospectively collected PROs following ACLR. Inclusion criteria were based on complete pre-operative and 2-year follow-up. Patients were categorized as acute with an injury to surgery interval of less than 60 days, those over 60 days were considered chronic. Descriptive analysis was conducted using Fisher’s exact tests and Chi-square analysis. A mixed linear model regression analysis was conducted to examine the effect of time on outcome variables using Restricted Maximum Likelihood (REML) across two groups (acute and chronic). The dependent variables were: IKDC Score, EuroQol Score, PROMIS Global Mental and Physical Health Scores, KOOS Score, and VAS Pain Score with time as the primary fixed effect. Data was analyzed using Python version 3.8 with pandas and statsmodels packages. 



Results: 97 out of 1235 patients from the institutional database met the inclusion criteria, with 54 chronic, 43 acute, 62 males, 35 females, and a median age at the time of surgery of 28 [21, 40]. The median BMI was 25.2 [23, 28.2], 26.6 [23.3, 30.1] for chronic cases and 24.2 [22.6, 26.8] for acute cases (p < 0.011). ACL grafts included 25 autografts and 72 allografts. Autograft was used more frequently in acute cases (p < 0.011), while chronic cases had an increased use of allografts (p < 0.011). Overall median PROs improved: from 50.6 to 86.2 (IKDC), 0.7 to 0.8 (EuroQol), 56 to 59 (PROMIS Global Mental Health), 50.8 to 57.7 (PROMIS Global Physical Health), 66 to 92 (KOOS), and 3 to 1 (VAS Pain). Linear mixed model analysis revealed a significant positive effect of time on IKDC (p < 0.001), and a random effects analysis demonstrated a group variance of 2.355, indicating variability in IKDC scores between acute and chronic groups. 



Conclusion: Using a 60-day cut-off for defining acute versus chronic ACLR showed greater improvement in median PROs. The IKDC score is a valuable predictor to compare acute versus chronic ACL injuries using 60 days as a cutoff for chronicity. Using this marker may aid in optimizing future surgical timing and recommendations that will improve individual patient recovery.

The Effect on Patient-Reported Outcomes in Acute vs. Chronic ACL Reconstruction

The Impact of Concomitant Pathologies on Patient Outcomes in Acute vs. Chronic ACL Reconstruction

Authors: Blake Padgett BS, Jonathan Brutti BS, Camila Torres-Caiaffa BA, Alexandra Moutafis BS, David Vasserman BS, Mendel Shloush BS, Jose Lima BS, Carlos Simon BS, Carlos Bermudez BS, Carolina Carrandi BS, Anshul Saxena BDS PhD, Matthias R. Schurhoff MD, Luis A. Vargas MD PhD, Gautam P. Yagnik MD, John E. Hechtman MD, John E. Zvijac MD, John W. Uribe MD

Background: ACL reconstruction (ACLR), a prevalent orthopedic procedure, often involves concomitant meniscal and chondral damage. Current literature lacks consistent differentiation between acute and chronic ACLR regarding short-term outcomes and their relationship with concomitant pathologies. This study compares the impact of surgical timing and the presence of meniscal and chondral pathologies on patient-reported outcomes (PROs).

Methods: This study used a historical cohort with prospectively collected PROs following ACLR. Inclusion criteria required complete pre-operative and 2-year follow-up data. Patients were categorized as acute if the injury-to-surgery interval was less than 60 days, and chronic if over 60 days. Dependent variables included IKDC, EuroQol, PROMIS Global Mental and Physical Health, KOOS, and VAS Pain scores, with time as the primary fixed effect. Intraoperative data included the location of chondral lesions and detailed meniscal injuries. A mixed linear model regression analysis examined the effect of time on outcome variables using REML across two groups (acute and chronic). Data was analyzed using Python 3.8 with pandas and statsmodels packages.

Results: Of 1235 patients, 97 met the inclusion criteria (54 chronic, 43 acute). Of these, 73 (75.3%) had an ACL tear with concomitant pathology (72.1% acute, 77.8% chronic). Medial meniscal tears were found in 45.4%, lateral tears in 60.8% with partial tears most frequently associated with the posterior horn (73.9% medial, 47.5% lateral). Medial chondral lesions were found in 22.7%, lateral in 18.6%, and patellofemoral in 41.2%. Among acute patients, 53.5% had meniscal injuries, 25.6% had chondromalacia, and 20.1% had both. Among chronic patients, 31.5% had meniscal injuries, 5.6% had chondromalacia, and 44.4% had both. Acute injuries had more meniscal tears (p < 0.048), while chronic injuries had significantly more combined meniscal and chondral pathology (p < 0.027). Chondral lesions showed no significant difference between timing of intervention. Overall, partial meniscectomies were performed in 55.6% (20.6% acute, 35% chronic) and meniscal repairs in 46.4% (23.7% acute, 22.7% chronic). Linear mixed model analysis showed a significant positive effect of time on IKDC scores (p < 0.001). Random effects analysis indicated a group variance of 2.355, highlighting variability in IKDC scores between acute and chronic groups.

Conclusion: Combined chondral lesions and meniscus pathologies were more prevalent in chronic ACL reconstruction. Acute intervention showed greater improvement in median PROs compared to delayed reconstruction. Earlier treatment plans may reduce the occurrence of combined meniscal injury and cartilage damage in ACLR and may improve patient outcomes.

The Impact of Concomitant Pathologies on Patient Outcomes in Acute vs. Chronic ACL Reconstructions

Abstract Title: TKA Femoral Flexion Angle Distribution and Range of Motion

Background: Femoral implant flexion angle (FF) is an underutilized metric with wide reported ranges. Increased understanding of current FF use may establish specific sagittal alignment targets. 

Methods: Demographics, knee ROM, and implant alignment parameters were collected for patients undergoing TKA with a CT-based robotic knee replacement system. The range and distribution of FF angles was determined. “High-FF” and “Low-FF” groups were divided at the FF mean. ROM measurements were taken in four windows: Preoperative, Early postoperative (7- 42 days), Middle postoperative (43-135 days), and Late postoperative (>136 days). ROM was compared between groups. 

Results: 976 patients of age 66.3±8.74 years, BMI 32.9±10.9, and 56.6% female. Average FF was 4.04°±2.10° flexion [0°-9°]. The Low-FF group [0.0°-4.0°] had 528 patients. The High-FF group [4.5°-9.0°] had 448 patients. There were no differences in preoperative knee parameters: varus/valgus alignment, flexion/extension ROM (p>0.2). High-FF patients were often female (Low-FF 53.0%; High-FF 62.5%; p=0.006) and more frequently cemented implants (Low-FF 14.4%; High-FF 20.4%; p=0.020). High-FF patients had smaller femoral implants (Size 4 or lower: Low-FF 52.2%; High-FF 68.7%; p<0.001), smaller tibial implants (Size 4 or lower: Low- FF 50.1%; High-FF 63.9%; p<0.001), and lower tibial slope (Low-FF 3.2°; High-FF 3.0°; p<0.001). There were no differences in patient size (p>0.1) or femur-tibia size mismatch frequency (p=0.539). 193 patients had measurements in all four windows. Repeated measures found no ROM differences between groups at any timepoint. 

Conclusion: The observed femoral implant flexion angles assumed a normal distribution ranging from 0° to 9° flexion, centered at 4° flexion. Patients receiving a femoral flexion angle above 4° were more often female, cemented, had lower tibial slope angle, and smaller femur and tibia implant sizes. Patients with larger femoral flexion angles showed no difference in flexion or extension range of motion at any timepoint when compared to patients with smaller femoral flexion angles. 


TKA Femoral Flexion Angle Distribution and Range of Motion

Background:
Approximately 400,000 ACL reconstructions are performed each year in the United States. Effective ACL injury prevention programs may be paramount in reducing this significant injury burden. 
Objective: To determine the effectiveness of ACL injury prevention programs and generate updated guidelines that can be implemented to protect athletes from these injuries.

Methods:
Embase, PubMed, and Ovid (MEDLINE) were searched in accordance with PRISMA guidelines. Included studies focused on ACL injury prevention as opposed to treatment and provided data on ACL injury rates after intervention implementation. Using random-effects models, the pooled risk ratio (RR) was generated for all data. Sub-analyses were completed for female-only, high school vs. collegiate/professional, handball, soccer, and balance board data.

Results:
A total of 18 articles were identified (9 randomized control trials, 9 prospective cohort studies). The 25,166 studied athletes played handball, soccer, basketball, or volleyball (mean age = 19.3, SD = 3.6 years; >85% female). All interventions were studied for a minimum of one season (mean = 1.3, SD = 0.59). Athletes who participated in an ACL injury prevention program were significantly less likely to sustain an ACL rupture with a pooled RR of 0.46 (95% CI, 0.36-0.57; P < 0.01; I2 = 49%). When analyzed by age, there was a significant risk reduction in ACL rupture for collegiate/professional athletes over age 18 (RR = 0.50; 95% CI, 0.38-0.64; P < 0.01; I2 = 66%) but no significant change for players under age 18 (RR = 0.35; 95% CI, 0.22-0.55; P = 0.47; I2 = 0%). Of the 12 studies including female players, the pooled RR was 0.57 and not statistically significant (95% CI, 0.43-0.74; P = 0.13; I2 = 32%). There was no significant RR for athletes playing soccer (RR = 0.30; 95% CI, 0.19-0.46; P = 0.06; I2 = 47%) or handball (RR = 0.66; 95% CI, 0.46-0.96; P = 0.38; I2 = 5%). Players who participated in programs including balance boards exhibited a significantly lower risk of ACL rupture (RR = 0.49; 95% CI, 0.35-0.67; P < 0.01; I2 = 74%).

Conclusion:
Athletes who did not partake in an ACL injury prevention program were nearly twice as likely to sustain an ACL rupture compared to those who did, with particular ACL injury risk reduction in collegiate/professional athletes and those who used balance boards. This study provides strong support for using neuromuscular training programs to significantly reduce the risk of ACL rupture among athletes.

Training to Stay in the Game: A Systematic Review and Meta-Analysis of ACL Injury Prevention Programs

Gonzalo F. Del Rio Montesinos 
Abstract Title : Unveiling the Risks: A Deep Dive into Vertebral Artery Injuries Post Cervical Disc Arthroplasty 
Background
Cervical Disc Arthroplasty (CDA) treats cervical disc degeneration and spinal compression, offering a high success rate and improved neck disability index. During CDA, the vertebral artery (VA), a major blood vessel branching from the subclavian artery, is at risk. This courses the transverse foramen of C2-C6 vertebrae, exits at C2, and enters the skull via the foramen magnum. Injuries are often due to anatomical variations, though rare, can cause severe complications. The objective of this narrative review is to analyze variables such as Normal Anatomy, FDA-approved Devices, increase CDA, the prevalence of VAI in the anterior approach, case reports regarding the injury, preventative measures, and treatment were considered. 

Methods
The articles chosen were from June 30th, 2000, to June 30th, 2024, and sourced from PubMed, Science Direct, and Web of Science. The keywords were cervical, cervical disc, vertebral artery, vertebral artery injury, disc arthroplasty, and degenerative disc. 

Results 
Extensive literature exists regarding the anatomic variations such as a 7.6% occurrence among 250 individuals. The anterior approach of CDA has a 0.4% occurrence of VAI. Pre-operative MRI and post-operative advanced imaging techniques such as MRI must be implemented with more frequency to determine artery course and health outcomes. Physician experience has significant effects upon possible injuries. Surgeons with < 300 procedure experience had a 0.33% possibility of injuring the artery and those with > 300 had 0.06%. CDA has been implemented in Europe since the 1960s however it wasn’t until 2007 where the FDA approved the first CDA device for the USA. Among 11 FDA-approved devices, eight reported blood loss, two Vascular Intra op, and one cerebrovascular bleeding, however no device indicated to have a VAI as a complication. Two case reports were found regarding VAI following CDA. In VAI, a stent has 97% success rate, however one must consider long term re-stenting and symptom reappearance. Two case reports regarding VAI following CDA indicated the lack of literature of the injury and the possible complication when approaching the procedure. In the years 2007-2013 there has been a nonlinear 190% increase in the use of CDA, exponentially replacing anterior cervical fusion and one must consider that this continuous implementation will bring about increased case reports regarding complications. 

Conclusion
VAI must be considered when approaching a CDA due the higher prevalence of these procedures being implemented. Anatomic variations, Physician Experience, preventative and treatment management are factors to consider in VAI. 


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