United States

Periprosthetic joint infections are relatively rare complications of total joint replacements that are becoming increasingly common. The standard of care involves the placement of a temporary spacer made out of polymethyl methacrylate (PMMA) bone cement combined with antibiotics. The rate of major complication can be as high as 12 % for PMMA spacers. Therefore, the purpose of this study was to develop a method to produce a biocompatible material that could be 3D printed, provide mechanical support needed for ambulation, and deliver a therapeutic dose of antibiotics. Printed structures were successfully fabricated out of Biomed Clear (BMC) doped with up to 16% Gentamicin or 10 % Vancomycin. PMMA and BMC composites were characterized with differential scanning calorimetry, dynamic mechanical analysis, wear testing, compression testing, and a 30-day drug elution study. The thermoset properties of the BMC allowed for the compressive properties to remain unchanged as antibiotics were added to the polymer, but limited the amount of drug that eluted out of the composite. In contrast, the thermoplastic properties of PMMA led to the compressive properties to decrease with the addition of antibiotics, but PMMA was able to elute significantly more antibiotics. This study described a novel method to 3D print load bearing structures that can release antibiotics over 30 days. BMC composites have some advantages and disadvantages compared to PMMA that need to be considered when developing new treatments for orthopaedic infections. 


2023 AMA Research Challenge

A 3D printed, High Strength and Drug Eluting Composite for the Treatment of Periprosthetic Joint Infections


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INTRODUCTION: Obesity is the most common modifiable risk factor necessitating medical optimization prior to total joint arthroplasty surgery. At our institution, patients with a BMI >40 are referred to an interdisciplinary medical weight management program. The purpose of this study is to examine whether sustained treatment in the program leads to increased weight loss, continued orthopedic follow-up, and an increased likelihood of undergoing total joint arthroplasty surgery.

METHODS: A retrospective review of the medical record identified 136 patients with hip or knee arthritis and a BMI >40 who were referred to our medical weight management clinic over a two-year period. These patients were divided into three groups: those that failed to participate, those with a single visit, and those who underwent sustained treatment. Records were reviewed for demographic data, treatment interventions, and weight-loss and follow-up outcome measures. Continuous variables were assessed with t-test, and Fisher’s exact test was performed for categorical variables.

RESULTS: Patients with sustained treatment lost an average of 14 pounds versus 1.3 in those who attended a single appointment (p=0.01). 61.1% of patients with sustained treatment continued to follow-up in the orthopedic clinic, compared to 27% of patients who did not participate (p<0.01). 22.2% of patients with sustained treatment eventually underwent total joint arthroplasty surgery compared with 6.3% of patients who did not participate (p=0.02). 88.9% of patients with sustained treatment were treated with novel weight loss medications, with semaglutide the most popular choice.

CONCLUSION: Morbidly obese patients that engage in sustained treatment in an interdisciplinary medical weight management program experience greater weight loss, improved orthopedic follow-up rates, and a higher rate of total joint arthroplasty surgery when compared to those with minimal or no participation. The use of novel weight loss medications in achieving optimal outcomes in this cohort remains promising.

Sustained Medical Weight Management Program Leads to Increased Weight Loss and Arthroplasty Surgery

Background
Bone autograft is a mainstay in the surgical treatment of fracture nonunion. A traditional donor site for autologous bone graft harvest is the anterior or posterior iliac crest. A bone grafting technique that has gained favor over the past decade has been the Reamer/Irrigator/Aspirator (RIA) system (Synthes,Inc, West Chester, PA). Both techniques come with complications including donor site pain and iatrogenic fracture. The purpose of this study is to compare complications between autogenous bone graft harvest using the RIA system with subsequent prophylactic retrograde intramedullary nailing (rIMN) and the more common posterior iliac crest bone graft (PICBG) technique, as reported in the literature.

Methods
A single center retrospective cohort study was conducted to evaluate all patients who underwent prophylactic retrograde intramedullary nailing after bone graft harvest of the femur using the RIA device between January 2017 and September 2022 by a single surgeon. All patients were over the age of 18 and treated at the institution. All operations performed during January 2017 and September 2022 were manually reviewed from the surgeon daily schedule to identify pertinent procedures. Data collection was performed using the digitized medical records from the institution’s EMR (EPIC). 

Results
Thirty-six patients who underwent retrograde Reamer-Irrigator-Aspirator (RIA) with prophylactic intramedullary nailing were evaluated in this study. Of the 36 patients, two reported harvest site pain (5%). Three patients (8%) had an osteoporosis diagnosis, eleven (30.5%) had an osteomyelitis diagnosis, and four (11%) received prophylactic nailing for cancer. No subjects demonstrated a femoral neck fracture following prophylactic retrograde intramedullary nailing.

Conclusion
RIA with Prophylactic Intramedullary Nailing is a favorable option for bone graft harvest and prophylactic fixation. It has a lower harvest site morbidity, measured by harvest site pain, as compared to anterior or posterior iliac crest bone graft technique.

Retrograde Reamer-Irrigator-Aspirator (RIA) with Prophylactic Intramedullary Nailing vs Posterior Iliac Crest for Bone Grafting

1. Background
Approximately 1.2 million spine surgeries are performed each year in the US. Of those, an estimated 60-80% are successful, while 20-40% require revision due to a wide range of causes. Additionally, recovery from spine surgery often requires significant rehabilitation and care plan adherence, which can be impacted by biopsychosocial factors. As follows, substance use and other psychiatric comorbidities can worsen spine surgery patient outcomes.
Per the US Department of Health and Human Services, 61.2 million Americans over 12 years old use an illicit substance, and 9.2 million misuse opioids. Furthermore, 46.3 million meet criteria for substance use disorder (SUD), but 94% receive no treatment, and the vast majority are unaware of their SUD. With both SUD and spine surgery numbers increasing, and the likelihood that the former negatively impacts the latter, more research is needed to better understand the effects of perioperative substance use, both illicit and prescription, on the outcomes of spine surgeries to elucidate the significance of this emerging public health threat.
2. Methods
The PubMed database was searched in June 2023 using spine disease, spine surgery, and substance use search terms. Opinion articles, studies on extraspinal surgeries, and ongoing studies were excluded, but review articles were eligible for inclusion. Included studies tracked perioperative substance use and related spine surgery outcomes.
3. Results
Thirteen of nineteen included studies investigated perioperative opioid use and collectively found deleterious postoperative effects of acute, subacute, and chronic opioid use in spine surgery patients. Impacts were consistent across prescription and illicit drugs, even in opioid naïve patients and those receiving low-dose
regimens, though SUD exacerbated effects.
One study investigated opioids and muscle relaxants and showed elevated reoperation risk with both compared to controls (40% and 19%, respectively). A case report series of patients with SUDs also found increased complications and inadequate follow-ups. Postoperative effects of these substances included increased pain, surgical site infection rates, reoperations, healthcare costs, and medical complication rates.
Data on cannabis use remains contradictory. One study demonstrated reduced complications; another, decreased length of hospital stays; others, no effect or increased complications.
4. Conclusion
Substance use diminishes spine surgery success rates and increases medical complications, reoperations, and healthcare costs, whether use is acute or continuous with chronic SUD. As such, enhanced preoperative screening and careful prescribing should be a high priority in these patients, and perioperative patient education may also mitigate risks resulting from postoperative pain management regimens.

Perioperative Prescription and Illicit Substance Use Profoundly Impacts Spine Surgery Outcomes

Childhood bone sarcomas are treated with chemotherapy and surgical resection, with limb salvage favored. Noninvasive expandable endoprostheses use magnet driven lengthening to minimize limb-length inequality in growing children. However, these endoprostheses can have complications sometimes requiring revision surgery. The aim of this study is to investigate the frequency and indications for revision surgery in patients with noninvasive expandable endoprostheses.

Revision Surgery of Non-invasive Expandable Endoprosthetic Reconstruction in Pediatric Patients

Background
Around the world more than 1 million total hip arthroplasties (THA) are performed annually. With such a high case volume and projected increase in future demand, it is advantageous to optimize cost and care around THAs. This study will investigate two approaches to THA, the direct anterior (DA) and posterior approach. Neither approach has an advantage regarding long term outcomes, however there is uncertainty whether one yields improved early outcomes. Some studies have favored the DA approach citing better early outcomes while others have described no difference between the two approaches. This study compares early outcomes in a rural patient population undergoing DA and posterior THA.

Methods
We retrospectively compared 66 DA and 48 posterior THA cases performed by a single surgeon at a healthcare system that serves 4 rural counties with total populations less than 50,000. Electronic medical record data between the years of 2017-2021 was used to gather information that included demographics, perioperative information, clinical follow up notes, and billing information. Demographic data including age, body mass index (BMI), sex, and American Society of Anesthesiology (ASA) classification was used to determine whether confounding variables existed between groups. The early outcomes consisted of length of stay (LOS), procedure time, dislocations, intraoperative fractures, discharge disposition, length of pain (number of postoperative days until patient no longer had pain with flexion, internal/external rotation of the hip joint), and length of physical therapy. Lastly a cost comparison was done between the two approaches. 

Results
There were no significant differences in the demographics data, procedure time, number of dislocations, number of intraoperative fractures, and length of physical therapy. The mean LOS (1.5 vs. 2.4 days, p = 0.000) and mean length of pain (21.7 vs. 49.1 days, p = 0.0000) were shorter in the DA group. Fifty-seven (86%) patients and thirty (62%) patients were discharged home in the DA and posterior groups respectively (p = 0.0001). The mean cost ($81,606 vs. $71,020, p = 0.0000) was higher in the DA group.

Conclusions
Overall, the patients who received the DA approach had a shorter LOS, shorter length of pain, and higher rate of discharge to home as compared to patients who received the posterior approach. There was no significant increase in procedure time, number of intraoperative fractures, or number of dislocations between groups. This suggests that there is an advantage to the DA approach for THA that results in superior early outcomes with no increased risk for adverse events. However, the cost associated with the DA approach is on average $10,586 higher when compared to the posterior approach. While there are limitations to this study, it examines a rural community-based hospital patient population that is not a common demographic in the literature when comparing approaches to THA.

Comparison of Early Outcomes Between Direct Anterior and Posterior Total Hip Arthroplasty in a Rural Community Hospital

Background
Wound complications are well documented following spine tumor surgery due to risk factors including prior radiation therapy, poor nutritional status, and immunocompromise. Increasing evidence has shown that a multidisciplinary approach to complex oncological spine reconstruction surgery can decrease wound complication rates. The goal of this study is to assess whether plastic surgery wound closure in the setting of spine tumor surgery can lead to a decreased rate of wound complications.

Methods
A retrospective analysis of 157 consecutive patients who underwent spine tumor surgery between October 2012 and October 2022 at a Level 1 Trauma Center was performed. Clinical data regarding pre- and post-operative oncological treatment, surgical management, intra- and post-operative complications, and quality of life surveys were collected. Patients were stratified based on plastic surgery involvement in soft-tissue reconstruction and wound closure. Post-operative complications and outcomes were analyzed between groups. Statistical significance was set at p < 0.05.

Results
130 (82.8%) oncological spine surgeries underwent closure by spine surgeons (SS) and 27 (17.2%) underwent closure by plastic surgeons (PS). The PS group was 33% (N=9) female compared to 38% (N=50) female for the SS group. The PS group was younger compared to SS group (55.3 ± 18.3 vs. 62.5 ± 16.1 years; p=0.035). The PS group had a greater number of levels fused (3.3 ± 4.5 vs. 2.3 ± 2.1; p= 0.049) but a lower number of levels decompressed (1.48 ± 1.5 vs. 2.4 ± 1.2; p<0.001) compared to the SS group.

Patients in the PS group had a longer operative time (362.6 ± 278.3 vs. 225 ± 84.5 minutes; p<0.001), greater blood loss (631.8 ± 576.3 vs. 480.6 ± 454.9 mL; p=0.048), and greater length of stay (57 ± 132 vs. 10 ± 15 days; p<0.001) compared to SS group, which could be attributed to increased complexity of the PS cases. Pre-operative and post-operative Day 3 Albumin (p=0.82), Hematocrit (p=0.095), Glucose (p=0.367) and HA1c (p=0.417) had no effect on wound healing in both surgical groups. The most common coverage performed in the PS group were local paraspinal advancement flaps. The PS group had 0% post-op wound complications, wound infections, or wound-related reoperations, while the SS group had 4% (N=5) wound-related reoperations.


Conclusion
Spine tumor patients are at increased risk for impaired wound healing and post-operative wound complications. A multidisciplinary approach to oncological spine surgery, involving both spine surgeons and plastic surgeons, can improve surgical outcomes and wound healing.

Outcomes and Spine Oncology Surgery With and Without Plastic Surgery Reconstruction

Background
Acute hip fractures are a public health problem that affect primarily older adults. Given the subtleties in different patient indications and classifications such as fracture type, preoperative mobility/functional status, and presence or absence of preexisting/symptomatic arthritis, Chat Generative Pre-trained Transformer (ChatGPT) may be a helpful clinical decision-making tool in the treatment plan to optimize patient outcomes. The purpose of this study was to evaluate the accuracy of ChatGPT-4.0 by comparing its appropriateness scores for acute hip fractures with the American Academy of Orthopedic Surgeons (AAOS) Appropriate Use Criteria (AUC) given various patient scenarios. 

Methods
Using the AUC as the gold standard, a numerical scale was utilized to quantify the appropriateness of 6 different treatments. Quantitative scores ranging from 1-9 were assigned as follows: 7-9 signifies “Appropriate,” 4-6 signifies “May Be Appropriate,” and 1-3 signifies “Rarely Appropriate.” ChatGPT-4.0 was prompted separately and asked to assign an appropriate score for each treatment. To measure any notable errors, AAOS AUC scores were subtracted from the ChatGPT-4.0 scores, and the mean error, mean absolute error, and mean squared error were calculated. Spearman’s rank correlation coefficients and paired t-tests were used to determine statistical significance.

Results
30 patient scenarios were evaluated among 6 different treatment options for a total of 180 paired scores. Spearman’s rank correlation testing found that there was a very strong positive correlation between AAOS and ChatGPT-4.0 scores for Multiple Cannulated Screw Fixation, a strong positive correlation between scores for THA and for Hemiarthroplasty, and a moderate positive correlation for Long Cephalomedullary Nails. There was a non-significant weak positive correlation between scores for Short Cephalomedullary Nails and for Sliding Hip Screw ± Anti-Rotation Screw. Using a paired t-test, there were significant differences between scores for Long Cephalomedullary Nails.

Conclusion
The AAOS AUC is designed to optimize treatment outcomes for acute hip fractures in adults by improving the quality of care, and minimizing short- and long-term mortality. The appropriateness scores for THA, Hemiarthroplasty, Long Cephalomedullary Nails, and Multiple Cannulated Screw Fixation determined by ChatGPT-4.0 were positively correlated with the AUC scores. ChatGPT-4.0 overestimated the appropriateness of THA, Hemiarthroplasty, and Long Cephalomedullary Nails. The scores to treat with Long Cephalomedullary Nails were non-equivalent. Although it demonstrated some utility in recommending the appropriateness of treatment options for acute hip fractures in older adults, clinicians should refrain from fully relying on ChatGPT-4.0. The AI model needs improvement to assist physicians and must be further evaluated.

Can Large Language Models Recommend Treatment for Hip Fractures?

INTRODUCTION:
Leveraging electronic health records (EHR) and linked biorepositories has the potential to elevate quality, efficiency and
sample size of studies evaluating etiology of rotator cuff tears (RCT). To date, no functionally validated algorithm reliably
identifies rotator cuff tear cases and controls form EHR systems. To facilitate this major need, we developed universal
phenotypic algorithms to classify RCT cases and controls from EHRs.
METHODS:
Using ICD9/10 diagnostic, CPT procedure codes and natural language processing (NLP), two versions of the algorithm
were developed to assess case and control status: a platinum, with image verification, and a silver, without image
verification. Both versions are ICD/CPT based with the option to add NLP. The algorithms were developed and validated
through manual blinded chart review of 525 medical records in the Vanderbilt University Medical Center (VUMC) Synthetic
Derivative.
RESULTS:
Only algorithms performing at 80% predictive value (PV) or higher were considered. Algorithms that only relied on ICD
diagnostic codes for rotator cuff tear had PV < 80%, and were substantially improved by adding evidence of imaging (+PV
=87%). Code based Algorithms relying on surgical CPT codes had the greatest PV of code based algorithms
(+PV=88.7%). For both cases and controls, NLP improved PV (+PV cases: ICD/CPT only= 82%, w/NLP = 98%; -PV
Controls: ICD/CPT only= 96.7%, w/NLP= 94.7%). For cases, addition of NLP increased sample size (ICD/CPT
only=12,777, w/NLP=66,907). Generally, requiring imaging marginally increased PV but substantially decreased sample
size for both cases and controls (Platinum: Cases n= 10,048, Controls n= 14,236; Silver Cases n=69,615, Controls
n=1,825,797).
DISCUSSION AND CONCLUSION:
We successfully developed algorithms that can be applied to any EHR system to identify RCT case/control status. These
phenotypic algorithms will allow the field to efficiently scale up high-quality data from EHRs, paving the way for previously
unimaginable big-data studies in understanding the etiology of RCT.

Universal Algorithms for the Identification of Rotator Cuff Cuff Tear Status From 
Electronic Health Record Systems

Background
Anatomic Total Shoulder Arthroplasty (ATSA) and Reverse Total Shoulder Arthroplasty (RTSA) reliably alleviate pain and restore shoulder function for a variety of indications. However, these procedures are not well-studied in patients with neurocognitive impairment. Therefore, the purpose of this study was to investigate whether patients with dementia or mild cognitive impairment (MCI) have increased odds of surgical or medical complications following arthroplasty.

Methods
The PearlDiver database was queried from April 2010 through October 2021 to identify a cohort of patients who underwent either ATSA or RTSA and had a minimum 2-year follow-up. Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes were used to stratify this cohort into three groups: (1) patients with dementia, (2) patients with MCI, and (3) patients with neither condition. Surgical and medical complication rates were compared among these three groups.

Results
The overall prevalence of neurocognitive impairment among patients undergoing TSA was 3.0% in a cohort of 92,022 patients. Patients with dementia had increased odds of sustaining a periprosthetic humerus fracture (OR = 1.46, p <0.001), developing prosthesis instability (OR = 1.72, p < 0.001), and undergoing revision arthroplasty (OR = 1.55, p = 0.003) after RTSA compared to patients with normal cognition. ATSA patients with dementia did not have an elevated risk of surgical complications or revision. Conversely, RTSA patients with MCI did not have an elevated risk of complications or revision, although ATSA patients with MCI had greater odds of prosthesis instability (OR = 2.51, p = 0.008). Additionally, patients with neurocognitive impairment had elevated odds of medical complications compared to patients with normal cognition, including acute myocardial infarction and cerebrovascular accident.

Conclusion
Compared to patients with normal cognition, RTSA patients with pre-operative dementia and ATSA patients with pre-operative MCI are at increased risk for surgical complications. Moreover, both ATSA and RTSA patients with either pre-operative MCI or dementia are at increased risk for medical complications. As the mean age in the U.S. continues to rise, special attention should be directed towards patients with neurocognitive impairment to minimize post-operative complications after TSA.

Total Shoulder Arthroplasty in Patients with Dementia or Mild Cognitive Impairment

Background 

Increased preoperative shoulder dislocations are associated with recurrent instability and greater glenoid bone loss. Initial instability events and subsequent episodes can result in 6.8% and 20% increased glenoid bone loss respectively. Glenoid bone loss increases the risk of instability recurrence and poor outcomes following shoulder stabilization surgery. Low socioeconomic status (SES) indicators, such as high Area Deprivation Index (ADI) and non-commercial insurance status, correlate with emergency room visits and delays to orthopaedic care. This study assesses the correlation between ADI, insurance status, and preoperative glenoid bone loss. We hypothesized higher national ADI and non-commercial insurance would correlate with greater levels of radiographic glenoid bone loss. 



Methods 

339 Bankart repair patients were identified. Data obtained included demographics, national ADI, insurance status, and glenoid bone loss. National ADI was obtained utilizing the Neighborhood Atlas Website and patients’ home addresses. Patients were excluded for prior ipsilateral shoulder surgery (N=16), lack of viewable imaging (N=97), and low-quality magnetic resonance imaging (MRI)(N=34). Glenoid bone loss was measured using the Best-fit circle method on high-quality MRIs (i.e., Fast imaging employing steady-state acquisition (FIESTA)). Three-dimensional alignment of images provided the best glenoid en face view. Researchers were blinded to ADI and insurance status during radiographic analysis and inter- and intra-observer reliability testing. Glenoid bone loss was compared between insurance types using one-way ANOVAs. Before evaluating the ADI and glenoid bone loss association, a scatterplot was generated to qualitatively assess the nature of the relationship. A curve fitting tool determined a quadratic non-linear regression best characterized the association between ADI and glenoid bone loss. 



Results 

192 patients (23% female; 23.9±7.5 years of age; national ADI=16.7%±16.0%) were included. Patients experienced 9.50±6.59% glenoid bone loss. A significant quadratic association between national ADI and glenoid bone loss (R2=0.483, p<0.001) was observed. Individuals with non-commercial insurance experienced greater glenoid bone loss compared to commercial insurance (commercial=8.80±6.46%, other=12.52±6.36%, p=0.003). Interobserver reliability was .910; intraobserver reliability was .948. 



Conclusion 

Our findings indicate a positive association between area deprivation and MRI-measured glenoid bone loss in patients with anterior shoulder instability. Patients with low SES indicators, such as high ADI and non-commercial insurance, are more likely to have greater glenoid bone loss and could be at risk for increased rates of pre- and postoperative instability. While a correlation between low SES indicators and glenoid bone loss has been demonstrated; the association of SES with surgical complexity and functional outcomes in this context should be explored.

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A 3D printed, High Strength and Drug Eluting Composite for the Treatment of Periprosthetic Joint Infections

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Sustained Medical Weight Management Program Leads to Increased Weight Loss and Arthroplasty Surgery

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