United States

Background
Cutibacterium, as a ubiquitous, commensal gram-positive organism, represents a diagnostic challenge for arthroplasty surgeons. The characteristics of Cutibacterium culture positivity in THA and TKA are not well understood.

Methods
1: Retrospective chart review of patients with Cutibacterium culture following THA or TKA. 
2: Patient baseline characteristics and lab results were analyzed using T-test and chi-squared analysis. 
3: Those who underwent subsequent surgery were evaluated at one year using MSIS ORT.

Results
Of those with Cutibacterium-positive cultures, 10 of 21 THAs (47.6%) preoperatively met MSIS infection criteria, while 7 of 8 TKAs preoperatively met MSIS criteria (87.5%) (p= 0.13). Mean ESR was 36.4 mm/h for THA and 51.5 mm/h for TKA (p = 0.21), with mean CRP of 35.2 mg/dL for THA and 36.8 mg/dL for TKA (p = 0.95). Mean cell count and percent polymorphonuclear (PMNs) leukocytes from intra-articular aspiration was 27,055 with 68% PMNs for THA and 22,194 with 73.9% PMNs for TKA (p = 0.72 and p = 0.70, respectively). Mean cell count and percent PMNs was 24,143 (range of 95 to 128,205) with 58.9% PMNs for monomicrobial infections and 25,903 with 78.8% PMNs for polymicrobial infections. Of patients who underwent surgical intervention following positive periprosthetic Cutibacterium culture and had one-year follow-up (n =22), 16 (72%) had successful outcomes at one year. Only ASA was significantly different between the success and failure groups.

Conclusion
1) Cutibacterium PJI could lead to more subtle clinical and laboratory changes compared to other microbial species.
2) Patients with Cutibacterium-positive cultures following TKA or THA may not meet MSIS infection criteria.
3) Inflammatory markers and fluid characteristics of Cutibacterium-positive THAs and TKAs were elevated but had more subtle changes compared to accepted values for more virulent microbial species.
4) Patients who undergo surgical intervention following a positive periprosthetic Cutibacterium culture often have successful outcomes at one year.


AMA Research Challenge 2023

Patients with Positive Cutibacterium Culture Following Total Hip (THA) and Total Knee Arthroplasty (TKA) Often do not Meet MSIS Criteria for Infection

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Background: Noncontact anterior cruciate ligament (ACL) injuries remain a significant problem in young, female athletes who participate in sports involving frequent pivoting. Current risk assessment tools, such as 3D motion analysis of a drop-jump landing, have demonstrated inconsistent ability to identify those who will suffer noncontact ACL injury. Because combinations of unique geometric features of tibiofemoral anatomy (e.g., lateral tibial slope) are related to risk of noncontact ACL injury, physics-based computational models may improve identification of those at heightened risk. Thus, this study had three objectives: 1) to create athlete-specific, 3D, physics-based computational knee models; 2) to estimate ACL forces during a simulated pivot shift loading sequence using these models; and 3) to characterize the relationship between estimated ACL force and risk of first-time, noncontact ACL injury.

Methods: MRI data from 60 female athletes suffering first-time, noncontact ACL rupture and 60 sex-, age-, and sport-matched controls from the same team were utilized. Imaging was obtained on contralateral, uninjured knees of injured athletes, and the same side of matched controls. To accomplish our first objective, volumetric representations of tibiofemoral bone, articular cartilage, and menisci were incorporated into a physics-based computational modeling pipeline. To simulate a pivot shift, we sequentially applied 100 N of compression, an 8 Nm valgus moment, and a 30 N anterior-directed load. At peak applied loads, we recorded estimated ACL force. Logistic regression was used to quantify the risk associated with increased ACL force (α = 0.05).

Results: Estimated ACL forces were, on average, 22.5 N (95% CI: 6.7 – 38.3 N) greater in injured athletes than in their uninjured teammates (mean  SD: 119.0  41.0 N vs. 96.5  42.7 N; p=0.003). Of the 60 injured athletes, 70% (n=42) had greater estimated ACL forces than their uninjured teammates. The odds ratio for each one-SD increase in ACL force was 1.73 (1.18 – 2.55; p=0.005), indicating a 73% increase in likelihood of ACL injury for each one-SD increase in force.

Conclusion: This physics-based computational model revealed significantly greater estimated ACL forces in injured athletes compared to uninjured controls. The use of athlete-specific 3D knee models within our framework allows for detailed investigation of the relationship between knee biomechanics and injury risk with potential utility as a screening tool in female athletes. The association between heightened ACL force and injury risk highlights the importance of addressing unfavorable knee mechanics to enhance injury risk assessment and prevention strategies for female athletes.

Computational Knee Models Reveal Greater Estimated ACL Forces During Simulated Pivot Shift in Female Athletes with Noncontact ACL Injuries: Case-Control Analysis

Pelvic ring fractures (PRF) are rare among all fractures (20/100,000), but have significant associated morbidity and mortality. PRF are often classified into the Young-Burgess classification and the Tile AO classification. The Young-Burgess Classification uses a force vector applied to the pelvic ring to classify the different PRF into lateral (LC), anterior-posterior (APC), and vertical shear (VS). Conversely, the Tile classification is based on stability - Type A, Type B, and Type C. There is limited research that compares these two classification systems. This project consolidates the results of many papers to determine which classification system has better clinical prediction and treatment outcomes and is more reliable. 

Using a systematic approach, PubMed searches were performed using various key words: “Young”, “Burgess”, “Tile”, “presentation”, “treatment”, “pelvic ring” in the Title/Abstract. Only studies on human subjects were included. Studies after 2000 were reviewed to compare reliability of the systems and the clinical outcomes for each classification. Studies after 2013 were included to compare the treatment outcomes of PRFs based on classification. 

Reliability of the classification systems positively correlated with an increase in years of experience. When comparing the reliability, Young-Burgess is shown to have moderate-to-substantial level of agreement for classifying PRFs when accounting for expertise level, while Tile showed substantial agreement between specialists only. For predicting mortality, Young-Burgess is found to be superior to Tile in one study, while another study found no significant difference between the two systems. Another study found that Young-Burgess and Tile systems can be useful in predicting the likelihood of severe injury and communicating with consultants, but cannot reliably predict mortality. Early and appropriate management of PRFs is deemed important since they are associated with life-threatening hemorrhage and are significant causes of morbidity and mortality. Tile B and LC fractures had higher frequency of hemodynamically unstable fractures and underwent laparotomies more frequently than other fracture types. Additionally, Tile B and C, and APC and VS fractures had higher rates of sexual dysfunction in males and females. For treatment options, there was a moderate level of agreement among the surgeons' treatment plans based on radiographic assessment alone, as indicated by a mean kappa value of 0.47. This could have implications for patient care, as different surgeons may have different opinions on the best course of action based on their interpretation of the radiographs. However, the question of whether Young-Burgess and Tile can predict the treatment and the outcome still remains unanswered.

After review of current literature, it appears that Young-Burgess classification has slightly higher reliability and better prediction for mortality than Tile. However, there is a need for further research on how the classification systems can determine the treatment and outcomes to improve morbidity and mortality.


Comparing The Accuracy of Two Pelvic Ring Classification Systems: AO Tile and Young Burgess – A Review of the Literature

Background: As the most popular sport in the world, soccer has driven increased physical demands and higher levels of intensity, resulting in elevated levels of lower extremity injuries among players. Our study analyzed the effects of cleat stud patterns and models worn by players who sustained lower extremity injuries while playing in the English Premier League (EPL). 

Methods: Fifteen cleat models, 510 players, and 221 injuries were analyzed from the EPL 2021-22 season. The injured player cohort was established using Transfermarkt.com, while cleat attributes were obtained from footballbootsdb.com and were confirmed using product websites and online reviews. Odds ratios and confidence intervals were used to assess lower extremity injury risk. Stud patterns or cleat models were set as the experimental condition, with injury or no injury as the outcome.

Results: Our results suggest that very aggressive stud patterns have significantly higher injury odds when directly compared to mildly aggressive. In addition, the odds of players sustaining ankle or knee injuries were significant with very aggressive stud patterns, while the odds of players sustaining hamstring injuries were significant with both very aggressive and non-aggressive. Cleat models with significant total or specific lower extremity injury odds were Nike Mercurial, Adidas X, Nike Phantom GT, Adidas Predator, and Nike Tiempo.

Conclusion: EPL players who wear very aggressive stud patterns may be at higher risk for lower extremity injuries compared to those who wear mildly aggressive stud patterns. Players and clubs should evaluate their footwear choices to best mitigate their injury risk. 


Cleats Worn Versus Lower Extremity Injuries in the English Premier League

Introduction: Surgical management of Superior Labrum Anterior-to-Posterior (SLAP) tears remains controversial. Current management utilizes two well established procedures: biceps tenodesis (BT) and SLAP repair.

Purpose: The purpose of this study is to evaluate the complications associated with arthroscopic SLAP repair versus an open or arthroscopic biceps tenodesis to further elucidate optimal surgical management.

Methods:
Design: In this retrospective cohort study, a multicenter research network was utilized to evaluate de-identified patient information from 50 healthcare organizations (HCOs) and over 90 million patients on the US collaborative network.

Participants: Three cohorts with SLAP lesions (ICD10:S43.43) were evaluated for this study. Cohort A was defined as patients that had undergone arthroscopic SLAP repair (CPT:29807). Cohort B was identified as patients that had undergone arthroscopic biceps tenodesis (CPT:29828). Cohort C was patients that had undergone open tenodesis of the biceps (CPT:23430). Cohorts were propensity matched for type 2 diabetes, nicotine dependence, alcohol related disorders, and BMI. Cohorts were similarly propensity matched for demographic factors such as age at event, ethnicity, race, and sex.

Setting: Data was gathered from HCOs from May 15th, 2003, to May 15th, 2023. The outcomes evaluated were: disruption of surgical wound, deep vein thrombosis, mononeuropathy of upper limb, shoulder contusion, humeral fracture, sepsis, deceased, acute post-op pain, revision, shoulder stiffness, and rotator cuff strain. All outcomes were evaluated within 1 year post procedure.

Results: A total of 11,081 arthroscopic SLAP repairs, 9,960 arthroscopic biceps tenodesis, and 9,420 open biceps tenodesis were matched. Compared to arthroscopic biceps tenodesis, patients that underwent arthroscopic SLAP repair were 1.8 times more likely for revision (2.9% vs 1.6%, p < 0.0001). Compared to open biceps tenodesis, patients that underwent SLAP repair were 1.4 times more likely for revision (3.1% vs 2.3%, p = 0.0126) and 1.6 times more likely to have a subsequent rotator cuff strain diagnosis (5.1% vs 3.2%, p = 0.0002). Compared to SLAP repair, patients that underwent arthroscopic biceps tenodesis exhibited 1.3 times more instances of acute postoperative pain (5.2% vs 4.0%, p = 0.0112). Similarly, open biceps tenodesis exhibited 1.8 times more instances of acute postoperative pain (6.9% vs 3.8%, p < 0.0001) and 1.3 times more shoulder stiffness (11.8% vs 9.0%, p < 0.0001).

Conclusion: In the last 20 years (2003 to 2023), patients that had SLAP repair were associated with higher risk of revision surgery and subsequent rotator cuff strain diagnosis. Conversely, patients that underwent biceps tenodesis were associated with higher rates of acute postoperative pain and shoulder stiffness.

Superior Labrum Anterior-to-Posterior (SLAP) Repair is Associated with Increased Rate of Subsequent Rotator Cuff Diagnoses and Revision Surgery: A Propensity-Matched Comparison

Background
The success of modern total hip arthroplasty (THA) depends on accurate placement of implants in order to obtain a durable result. As direct anterior (DA) approach THA has become increasingly popular, more surgeons are now using intra-operative fluoroscopy to navigate cup position and to assess leg length. One limitation of traditional fluoroscopy is that it has historically been a qualitative, but not quantitative technology. Recently, fluoroscopy-assisted computer navigation software with the capability to assess intra-operative parameters quantitatively has emerged. Few studies have investigated the accuracy of this software in comparison to post-operative radiographs. Such a study would be an important contributor to the literature, as it would allow the arthroplasty surgeon to predict with confidence whether these measurements would be similar to those obtained by post-operative radiographs.
Methods
This is a prospective cohort study of consecutive patients undergoing unilateral anterior THA. 199 hips were analyzed fluoroscopically with intra-operative computer software (OrthoGrid Systems, Inc), determining LLD. At the two-week post-operative visit, these measurements were repeated on standing AP radiographs. Continuous variables were analyzed using Student’s t-test.
Results
The mean intra-operative LLD was 0.3 mm and the mean LLD on two-week follow-up was 0.6 mm (p=0.13). Intraoperatively, all 199 patients (100%) were navigated to LLDs within 5 mm; similarly on final standing AP films the number of patients with LLD within 5 mm was 196/199 (98%) (p = 0.25). The mean difference between the intra-operative LLD and post-operative LLD (ΔLLD) was 0 mm.
Conclusion
Total hip arthroplasty continues to be a tremendously successful procedure for eliminating pain and improving function of the arthritic hip, and a successful outcome in part depends on accurate placement of implants. We demonstrate in the present prospective study that fluoroscopy-assisted computer navigation software accurately predicts post-operative leg length discrepancy. For differences in measurements of leg-length discrepancy (ΔLLD), 69% of navigated measurements were within 2mm of those on post-op films, and 99% of measurements were within 5mm.

Does Fluoroscopy-Assisted Computer Navigation Accurately Predict Cup Position and Leg Length for Anterior Hip Arthroplasty?

Background: There currently is a paucity of literature regarding the risks gender-affirming hormone therapy (GAHT) presents in the transgender population. Understanding the effect of GAHT on transgender bone health and fracture risk is essential. The purpose of this study is to analyze the prevalence and locations of fractures in trans compared to cis patients while assessing the comorbidities present that may affect fracture risk. 

Methods: A retrospective analysis of fractures from 01/01/2020 to 01/01/2021 was performed with chart review being utilized to identify trans patients. The prevalence and anatomic locations of fractures in trans patients were then compared to that of cis patients. Comorbidities of both populations and assessment of bone mineral density with Dual-Energy X-ray Absorptiometry (DXA) scans in trans patients was also recorded. 

Results: The transgender population experienced more shoulder and upper arm fractures (p=0.004) and less lumbar spine fractures (p=.009). There was no difference in the anatomic distribution of other fractures. The number of fractures per individual in both cohorts was similar (p=.984). The prevalence of hypertension and depression was higher in the trans population (p<.001). Osteoporosis was lower in prevalence in the transgender population (p<.001). 

Conclusion: Fracture prevalence and anatomical location do not seem to be significantly different between the trans and cisgender populations. However, longitudinal prospective studies are needed to better understand the impact of GAHT on fracture risk among transgender patients. An emphasis on adequate charting for gender identity disorders and DXA scans is important for medical management in patients receiving GAHT.

A retrospective analysis of fractures in the transgender population 

Plantar fasciitis is one of the most common foot conditions presenting to a foot and ankle specialist. Surgical treatment outcomes following plantar fasciotomy vary but short-term studies have reported excellent early pain relief and significant improvements in symptoms. This study evaluates patient reported outcome scores collected pre- and post-op for patients who underwent percutaneous ultrasonic micro-tenotomy (PUT) plantar fasciotomy with PRP injection vs PUT plantar fasciotomy alone. 

Chart review data was collected on pain Visual Analog Scales (VAS), for patients treated surgically (plantar fasciectomy) by Orthopaedic Surgery department foot & ankle faculty members between December 2007 and December 2022. A total of 30 patients were identified. Exclusion criteria were patients younger than 18 years old and patients who had undergone plantar fasciectomy without the use of PUT or those who had undergone PUT but did not complete their pain VAS surveys. All statistical analyses were carried out using SAS 9.4 (SAS Inc., Cary, NC, USA). Descriptive statistics (mean, standard deviation, median, range, frequency, and percentage) were employed for summarizing measurements. Paired t test and two-sample t test were conducted to compare the measurements. Fisher’s exact test was used to compare gender distribution. The level of significance was set at 5%. 

Patients who received PUT with PRP had a statistically significant decrease in pain level compared to the PUT without PRP group. There was a significant decrease in pain level from pre-op visit (at least 1 month prior to operation) to last follow-up visit. The mean pain VAS at the pre-op visit was 7.69, with a standard deviation (SD) of 2.26 and the mean pain VAS at the last follow-up visit was 4.85, with a SD of 2.75. A paired t-test paired showed there was significant difference between pre-op and post-op pain VAS for each group, with a p-value of <0.0001. The pain VAS change in the PUT with PRP group was significantly larger than in the PUT without PRP group, a paired t-test yieled a p-value of <0.0325. The mean time between the initial visit and last follow-up visit was 19 months. The mean time following surgical intervention was 10 months. 

In the literature, most studies have found that PUT or PRP individually were successful in producing clinically and statistically significant improvements in pain and quality of life. However, there are limited studies looking at the synergistic use of PUT & PRP to show their combined impact on patient outcomes and pain relief. The findings of our study suggest that the dual use of PUT & PRP treatments could potentially lead to an increase in the longevity of pain relief.

Retrospective Evaluation of Ultrasound Guided Percutaneous Plantar Fasciotomy With and Without Platelet Rich Plasma

Background: Primary spine tumors are aggressive in nature and en bloc resection and reconstruction can be essential for preventing recurrence and improving survival. Although stereotactic navigation is becoming an indispensable tool for the placement of instrumentation in complex spine surgery, the evidence for its application in primary spine tumors is limited. 

Questions/purposes: The purpose of this systematic review was to describe: (1) the advances in technology and their application in primary spine tumor resection and reconstruction, (2) the efficacy in adequately achieving negative margins, and (3) the perioperative outcomes of these techniques.

Methods: A systematic review was registered with PROSPERO and performed according to PRISMA guidelines using the PubMed, Embase, and Ovid MEDLINE databases. All level I-IV clinical studies published in the English language investigating the application of stereotactic navigation for primary spinal tumors were included. 

Results: A total of 13 articles with 169 patients (94 males, 75 females) were included in the analysis. One study was level III evidence and 12 studies were level IV. Intraoperative computer tomography (CT) scan alone for stereotactic navigation was performed in 10 articles with 136 patients. Preoperative magnetic resonance imaging (MRI) was merged with intraoperative computer tomography (CT) in three studies with 33 patients. Nine studies with 131 patients reported intraoperative margins, of which, 103 patients had negative margins, 28 patients had positive margins. Eleven studies with 164 patients reported perioperative outcomes, of which 46 patients experienced one or more perioperative complications. 

Conclusion: 
There is moderate evidence to suggest that frameless stereotactic navigation is a safe and effective tool for obtaining negative margins during en bloc resections of primary spinal column tumors. Further cohort studies are necessary to critically evaluate if these initial trends persist across larger cohorts.


Advances in Stereotactic Navigation for Primary Spinal and Pelvic Tumor Resection and Reconstruction: A Systematic Review

Chat Generative Pre-Trained Transformer, or ChatGPT, is a large language model that has gained increased popularity among the general public, which can lead to unwarranted use of the model to make clinical recommendations for the treatment of anterior cruciate ligament (ACL) injuries. This study will evaluate and compare ChatGPT's two models, GPT-3.5 and GPT-4.0, in their ability to predict appropriate clinical recommendation ratings for 10 ACL treatment options based on 56 patient scenarios, as set by the AAOS Appropriate Use Criteria for ACL Treatment. In doing so, we hope to inform orthopedic surgeons and patients alike to remain cautious of ChatGPT's response in this field.

Can ChatGPT Models Appropriately Predict Treatment Options for Anterior Cruciate Ligament Injuries?

Background: Efforts have been made to promote awareness of female athlete differences from their male counterparts as well as minimize discrepancies in their wages and publicity. However, a critical component has been overlooked: establishing evidence-based recommendations specific to female athletes. Smith et al. notes that “female-targeted research related to sports science/sports medicine has failed to mirror the increase in participation and popularity of women’s sport.”(Smith et al., 2022) Achilles tendon rupture is one of the most common musculoskeletal injuries, occurring in 15 – 55 per 100,000 people annually.(Huttunen et al., 2014) Differences in injury rate and complications could be due hormonal effects, as estrogen receptors have been identified in lower limb tendons along with decreased Achilles tendon strain based on oral contraceptive use.(Bridgeman et al., 2010; Bryant et al., 2008; Liu et al., 1996) The primary purpose of this study is to audit the representation of female athletes in the literature regarding Achilles tendon repair.

Methods: An electronic search was performed using PubMed to identify articles related to Achilles repair using the standardized protocol by Smith et al. to assess female representation in research. (Smith et al., 2022) Studies were assessed by population, size, athletic caliber, study impact, research theme, and menstrual status.

Results: Female representation across all studies was 1783/10673 subjects (16.71%). Composition of included studies was predominantly mixed sex cohorts with 131/169 (77.51%) included studies. Within mixed sex cohort studies, the total representation of female athletes was 1651/8741 participants (18.89%). 32 studies were male only cohorts constituting 1540 participants while 3 studies were female only cohort studies comprised of 86 athletes. Importantly, the disparity between male and female representation worsened as the athletic caliber of the study population increased with 4.96% female representation in studies with professional athletes. No study collected data related to menstrual status and its potential relationship to Achilles rupture or post operative outcomes.

Conclusion: To our knowledge, this is the first review auditing the representation of female athletes in research related to Achilles rupture and repair. Mixed sex cohort studies underrepresented female athletes and male only cohort studies were more common than female only studies. These findings indicate a need for increased representation of female athletes in research related to Achilles repair. Future studies should focus on equal representation of female athletes and data collection related to sex specific hormones and menstrual status to improve recommendations and treatment of Achilles tendon ruptures for female athletes.


Next from AMA Research Challenge 2023

Computational Knee Models Reveal Greater Estimated ACL Forces During Simulated Pivot Shift in Female Athletes with Noncontact ACL Injuries: Case-Control Analysis