Early Outcomes of Lisfranc Injuries Treated with Arthrex InternalBrace: A Case Series.

Introduction: The treatment of Lisfranc injuries continues to evolve with time. The purpose of this study was to report early outcomes of patients with Lisfranc ligamentous injuries treated with the Arthrex InternalBrace, which has benefits to other previously described techniques. Materials and methods: We retrospectively identified 15 adult patients with Lisfranc injuries that were treated via open reduction internal fixation with the Arthrex InternalBrace (Naples, Fl). These patients were identified at two separate United States institutions between 2019 and 2022. Demographic data, mechanism of injury, and concomitant foot injuries were recorded. Outcomes were assessed by return-to-work or sport and time to weight-bearing. Secondary complications or revision surgeries were noted. Results: The mean patient age was 35 years. Eight patients had isolated Lisfranc ligamentous injuries and seven had additional intercuneiform instability, which required a supplemental limb of the fixation device. The most common mechanism of injury was a cutting/pivoting maneuver (n = 5) followed by fall (n = 4). The mean radiographic follow-up time was 7.3 months. The average time to weight-bearing as tolerated was 6.6 weeks (± 2.2). The average time to return-to-work/sport as tolerated was 14.1 weeks (± 3.6). Only two minor complications were noted at follow-up but no major complications or revision surgeries occurred. Conclusions: The outcomes of this case series suggest that the Arthrex InternalBrace is a viable option when performing open reduction and internal fixation of Lisfranc ligamentous injuries. Future prospective studies are needed to directly compare this device with alternative fixation methods.

Charcot Neuroarthropathy Is Associated With Higher Rates of Phantom Limb After Lower Extremity Amputation.

BACKGROUND: The incidence of phantom limb pain in patients with Charcot neuroarthropathy who undergo major amputation is not well described. The purpose of this study was to determine whether patients with Charcot neuroarthropathy and diabetes who underwent either a below-knee amputation (BKA) or above-knee amputation (AKA) had an increased rate of phantom limb pain compared with those with a diagnosis of diabetes alone. METHODS: Using international classification of disease (ICD) and common procedural terminology (CPT) codes, the TriNetX research database identified 10 239 patients who underwent BKA and 6122 who underwent AKA between 2012 and 2022. Diabetic patients with and without Charcot neuroarthropathy were compared in terms of demographics and relative risk of developing phantom limb pain after AKA or BKA. RESULTS: Age, sex, ethnicity, and race did not significantly differ between groups. Charcot neuroarthropathy was associated with significantly increased risk of phantom limb pain following both BKA (risk ratio [RR]: 1.2, 95% confidence interval [CI]: 1.1-1.3, P < .01) and AKA (RR: 1.6, 95% CI: 1.2-2.3, P < .0068). CONCLUSION: Our results indicate that patients with a coexisting diagnosis of Charcot neuroarthropathy who require BKA or AKA may have an increased risk of developing phantom limb pain. LEVELS OF EVIDENCE: Level III.

Current Trends in Total Ankle Replacement.

Ankle arthritis can result in significant pain and restriction in range of motion. Total ankle replacement (TAR) is a motion-preserving surgical option used as an alternative to total ankle arthrodesis to treat end-stage ankle arthritis. There are several generations of TAR techniques based on component design, implant material, and surgical technique. With more recent TAR implants, an attempt is made to minimize bone resection and mirror the native anatomy. There are more than 20 implant devices currently available. Implant survivorship varies among prosthesis types and generations, with improved outcomes reported with use of the more recent third- and fourth-generation ankle implants. Pre- and postoperative assessments of TAR are primarily performed by using weight-bearing radiography, with weight-bearing CT emerging as an additional imaging tool. Preoperative assessments include those of the tibiotalar angle, offset, and adjacent areas of arthritis requiring additional surgical procedures. US, nuclear medicine studies, and MRI can be used to troubleshoot complications. Effective radiologic assessment requires an understanding of the component design and corresponding normal perioperative imaging features of ankle implants, as well as recognition of common and device-specific complications. General complications seen at radiography include aseptic loosening, osteolysis, hardware subsidence, periprosthetic fracture, infection, gutter impingement, heterotopic ossification, and syndesmotic nonunion. The authors review several recent generations of TAR implants commonly used in the United States, normal pre- and postoperative imaging assessment, and imaging complications of TAR. Indications for advanced imaging of TAR are also reviewed. ©RSNA, 2023 Supplemental material is available for this article. Test Your Knowledge questions for this article are available through the Online Learning Center.

Establishment of a Neurodegenerative Charcot Mouse Model.

BACKGROUND: This study aimed to mimic the changes from Charcot neuropathic arthropathy in humans by examining the effects of exposing diet-induced obese (DIO) mice to neurotrauma through a regimented running protocol. METHODS: Forty-eight male wild-type C57BL/6J mice were obtained at age 6 weeks and separated into 2 groups for diet assignment. After a 1-week acclimation period, half of the mice consumed a high-fat diet (60% fat by kcal) ad libitum to facilitate neuropathic diet-induced obesity whereas the other half were control mice and consumed an age-matched standard low-fat control diet (10% fat by kcal). At age 12 weeks, half of the animals from each group were subjected to a high-intensity inclined treadmill running protocol, which has been previously demonstrated to induce neurotrauma. Sensory testing and radiographic analyses were periodically performed. Histopathologic analyses were performed post killing. RESULTS: DIO mice had significantly higher bodyweights, higher body fat percentages, and lower bone mineral density than wildtype control mice that were fed a normal diet throughout the experiment (P < .001 for each). DIO mice displayed significantly reduced sensory function in week 1 (P = .005) and this worsened over time, requiring 20.6% more force for paw withdrawal by week 10 (P < .001). DIO mice that ran demonstrated greater midfoot subluxation and tarsal instability over all time points compared with normal-diet mice that ran (P < .001). Histopathologic analyses revealed that DIO mice that ran demonstrated significant changes compared with controls that ran (P < .001 for each parameter). CONCLUSION: Changes akin to the earliest changes observed in or before joint destruction identified in diabetic Charcot neuropathic arthropathy in humans were observed. CLINICAL RELEVANCE: There is currently no standard of treatment for patients with Charcot neuropathic arthropathy. This study establishes a protocol for an animal model that can be used to study and compare interventions to treat this disease.

Vancomycin Powder Is Highly Cost-Effective in Total Ankle Arthroplasty.

Prosthetic joint infection (PJI) is a costly and potentially fatal complication in total ankle arthroplasty (TAA). Some surgeons apply topical vancomycin powder to minimize the risk of infection during TAA procedures. The purpose of our study was to determine the cost-effectiveness of using vancomycin powder to prevent PJI following TAA and to propose an economic model that can be applied by foot and ankle surgeons in their decision to incorporate vancomycin powder in practice. Using our institution's records of the cost of 1 g of topical vancomycin powder, we performed a break-even analysis and calculated the absolute risk reduction and number needed to treat for varying costs of vancomycin powder, PJI infection rates, and costs of TAA revision. Costing $3.06 per gram at our institution, vancomycin powder was determined to be cost-effective in TAA if the PJI rate of 3% decreased by an absolute risk reduction of 0.02% (Number Needed to Treat = 5304). Furthermore, our results indicate that vancomycin powder can be highly cost-effective across a wide range of costs, PJI infection rates, and varying costs of TAA revision. The use of vancomycin powder remained cost-effective even when (1) the price of vancomycin powder was as low as $2.50 to as high as $100.00, (2) infection rates ranged from .05 to 3%, and (3) the cost of the TAA revision procedure ranged from $1000 to $10 000.Levels of Evidence: IV.

Mesenchymal stromal cells and alpha-1 antitrypsin have a strong synergy in modulating inflammation and its resolution.

Rationale: Trauma, surgery, and infection can cause severe inflammation. Both dysregulated inflammation intensity and duration can lead to significant tissue injuries, organ dysfunction, mortality, and morbidity. Anti-inflammatory drugs such as steroids and immunosuppressants can dampen inflammation intensity, but they derail inflammation resolution, compromise normal immunity, and have significant adverse effects. The natural inflammation regulator mesenchymal stromal cells (MSCs) have high therapeutic potential because of their unique capabilities to mitigate inflammation intensity, enhance normal immunity, and accelerate inflammation resolution and tissue healing. Furthermore, clinical studies have shown that MSCs are safe and effective. However, they are not potent enough, alone, to completely resolve severe inflammation and injuries. One approach to boost the potency of MSCs is to combine them with synergistic agents. We hypothesized that alpha-1 antitrypsin (A1AT), a plasma protein used clinically and has an excellent safety profile, was a promising candidate for synergism. Methods: This investigation examined the efficacy and synergy of MSCs and A1AT to mitigate inflammation and promote resolution, using in vitro inflammatory assay and in vivo mouse acute lung injury model. The in vitro assay measured cytokine releases, inflammatory pathways, reactive oxygen species (ROS), and neutrophil extracellular traps (NETs) production by neutrophils and phagocytosis in different immune cell lines. The in vivo model monitored inflammation resolution, tissue healing, and animal survival. Results: We found that the combination of MSCs and A1AT was much more effective than each component alone in i) modulating cytokine releases and inflammatory pathways, ii) inhibiting ROS and NETs production by neutrophils, iii) enhancing phagocytosis and, iv) promoting inflammation resolution, tissue healing, and animal survival. Conclusion: These results support the combined use of MSCs, and A1AT is a promising approach for managing severe, acute inflammation.

Improving Randomized-Controlled Trials in Foot and Ankle Orthopaedics: The Need to Include Sociodemographic Patient Data.

BACKGROUND: The representation of sociodemographic data within randomized-controlled trials (RCT) regarding foot and ankle surgery is undefined. The purpose of this study was to determine the incidence of sociodemographic data being reported in contemporary foot and ankle RCTs. METHODS: Randomized-controlled trials within the PubMed database from 2016 to 2021 were searched and the full text of 40 articles was reviewed to identify sociodemographic variables reported in the manuscript. Data regarding race, ethnicity, insurance status, income, work status, and education were collected. RESULTS: Race was reported in the results in 4 studies (10.0%), ethnicity in 1 (2.5%), insurance status in 0 (0%), income in 1 (2.5%), work status in 3 (7.5%) and education in 2 (5.0%). In any section other than the results, race was reported in 6 studies (15.0%), ethnicity in 1 (2.5%), insurance status in 3 (7.5%), income in 6 (15.0%), work status in 6 (15.0%), and education in 3 (7.5%). There was no difference in sociodemographic data by journal (P = .212), year of publication (P = .216), or outcome study (P = .604). CONCLUSION: The overall rate of sociodemographic data reported in foot and ankle RCTs is low. There was no difference in the reporting of sociodemographic data between journal, year of publication, or outcome study. LEVEL OF EVIDENCE: Level II.

Factors Associated With Amputation Following Ankle Fracture Surgery.

Patients with diabetes mellitus (DM) are at increased risk of complications following ankle fracture surgery. Previous research suggests that patients of low socioeconomic status are at increased risk of amputation following orthopedic complications. The purpose of this research was to determine if low socioeconomic status increases risk of below-knee amputation (BKA) following ankle fractures among patients with DM. The National Inpatient Sample (NIS) was queried from 2010 to 2014 to identify 125 diabetic patients who underwent ankle fracture surgical fixation followed by BKA. Two cohorts (BKA vs no BKA) and a multivariate logistic regression model were created to compare the effects of independent variables, including age, sex, race, primary payer, median household income by ZIP code, hospital location/teaching status, and comorbidities. The most predictive variables for BKA were concomitant peripheral vascular disease (odds ratio [OR] 5.35, 95% confidence interval [CI] 3.51-8.15), history of chronic diabetes-related medical complications (OR 3.29, CI 2.16-5.01), age in the youngest quartile (OR 2.54, CI 1.38-4.67), and male sex (OR 2.28, CI 1.54-3.36). Patient race and median household income were not significantly associated with BKA; however, risk of BKA was greater among patients with Medicaid (OR 2.23, CI 1.09-4.53) or Medicare (OR 1.85, CI 1.03-3.32) compared to privately insured patients. Diabetic inpatients with Medicaid insurance are at over twice the odds of BKA compared to privately insured patients following ankle fracture. Furthermore, peripheral vascular diseases, uncontrolled diabetes, younger age, and male sex each independently increase risk of BKA.

Risk Factors For Prolonged Opioid Use After Spine Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: Our purpose was to evaluate factors associated with increased risk of prolonged post-operative opioid pain medication usage following spine surgery, as well as identify the risk of various post-operative complications that may be associated with pre-operative opioid usage. METHODS: The MarketScan commercial claims and encounters database includes approximately 39 million patients per year. Patients undergoing cervical and lumbar spine surgery between the years 2005-2014 were identified using CPT codes. Pre-operative comorbidities including DSM-V mental health disorders, chronic pain, chronic regional pain syndrome (CRPS), obesity, tobacco use, medications, and diabetes were queried and documented. Patients who utilized opioids from 1-3 months prior to surgery were identified. This timeframe was chosen to exclude patients who had been prescribed pre- and post-operative narcotic medications up to 1 month prior to surgery. We utilized odds ratios (OR), 95% Confidence Intervals (CI), and regression analysis to determine factors that are associated with prolonged post-operative opioid use at 3 time intervals. RESULTS: 553,509 patients who underwent spine surgery during the 10-year period were identified. 34.9% of patients utilized opioids 1-3 months pre-operatively. 25% patients were still utilizing opioids at 6 weeks, 17.3% at 3 months, 12.7% at 6 months, and 9.0% at 1 year after surgery. Pre-operative opioid exposure was associated with increased likelihood of post-operative use at 6-12 weeks (OR 5.45, 95% CI 5.37-5.53), 3-6 months (OR 6.48, 95% CI 6.37-6.59), 6-12 months (OR 6.97, 95% CI 6.84-7.11), and >12 months (OR 7.12, 95% CI 6.96-7.29). Mental health diagnosis, tobacco usage, diagnosis of chronic pain or CRPS, and non-narcotic neuromodulatory medications yielded increased likelihood of prolonged post-op opioid usage. CONCLUSIONS: Pre-operative narcotic use and several patient comorbidities diagnoses are associated with prolonged post-operative opioid usage following spine surgery. Chronic opioid use, diagnosis of chronic pain, or use of non-narcotic neuromodulatory medications have the highest risk of prolonged post-operative opioid consumption. Patients using opiates pre-operatively did have an increased 30 and 90-day readmission risk, in addition to a number of serious post-operative complications. This data provides spine surgeons a number of variables to consider when determining post-operative analgesia strategies, and provides health systems, providers, and payers with information on complications associated with pre-operative opioid utilization.

Biomechanical Comparison of Fiber Tape Device Versus Transarticular Screws for Ligamentous Lisfranc Injury in a Cadaveric Model.

BACKGROUND: The preferred method of fixation and surgical treatment for ligamentous Lisfranc injuries is controversial. Transarticular screws, bridge plating, fusion, and flexible fixation have been described, yet none have demonstrated superiority. Furthermore, screw fixation and plating often require secondary surgery to remove implants, leading surgeons to seek alternative fixation methods. PURPOSE: To compare transarticular screws and a fiber tape construct under a spectrum of biomechanical loads by evaluating the diastasis at 3 joints in the Lisfranc complex. STUDY DESIGN: Controlled laboratory study. METHODS: Eight matched pairs of fresh, previously frozen lower extremity cadaveric specimens were fixed with either 2 cannulated transarticular crossed screws or a fiber tape construct with a supplemental intercuneiform limb. The diastasis between bones was measured at 3 midfoot joints in the Lisfranc complex: the Lisfranc articulation, the second tarsometatarsal joint, and the intercuneiform joint. Measurements were obtained for the preinjured, injured, and fixation conditions under static loading at 50% donor body weight. Specimens then underwent cyclic loading performed at 1 Hz and 100 cycles, based on 100-N stepwise increases in ground-reaction force from 100 to 2000 N, to simulate postoperative loading from the partial weightbearing stage to high-energy activities. Failure of fixation was defined as diastasis ≥2 mm at the Lisfranc articulation (second metatarsal-medial cuneiform joint). RESULTS: There were no significant differences in diastasis detected at the Lisfranc articulation or the intercuneiform joint throughout all loading cycles between groups. All specimens endured loading up to 50% body weight + 1400 N. Up to and including this stage, there were 2 failures in the cannulated transarticular crossed-screw group and none in the fiber tape group. CONCLUSION: The fiber tape construct with a supplemental intercuneiform limb, which does not require later removal, may provide comparable biomechanical stability to cannulated transarticular crossed screws, even at higher loads. CLINICAL RELEVANCE: Ligamentous Lisfranc injuries are common among athletes. Therefore, biomechanical evaluations are necessary to determine stable constructs that can limit the time to return to play. This study compares the biomechanical stability of 2 methods of fixation for ligamentous injury through a wide spectrum of loading, including those experienced by athletes.

Cost-Effective Modeling of Thromboembolic Chemoprophylaxis for Total Ankle Arthroplasty.

BACKGROUND: Symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) can cause substantial morbidity and mortality. To prevent this complication, surgeons often prescribe postoperative chemoprophylaxis. However, much controversy exists regarding the efficacy of chemoprophylaxis because of the limited studies exploring its use. Furthermore, even less is known about its cost-effectiveness. Therefore, this study sought to determine the cost-effectiveness of commonly prescribed chemoprophylactic agents using a break-even analysis economic model. METHODS: The literature was searched, and an online database was used to identify patients who developed a symptomatic VTE after undergoing TAA. Our institutional records were used to estimate the cost of treating a symptomatic VTE, and an online drug database was used to obtain the cost of commonly prescribed chemoprophylactic agents. A break-even analysis was then performed to determine the final break-even rate necessary to make a drug cost-effective. RESULTS: The low and high rates of symptomatic VTE were determined to be 0.46% and 9.8%. From 2011 to 2021, a total of 3455 patients underwent total ankle arthroplasty. Of these patients, 16 developed a postoperative symptomatic VTE (1.01%). Aspirin 81 mg was cost-effective if the initial symptomatic VTE rates decreased by an absolute risk reduction (ARR) of 0.0003% (NNT = 31 357). Aspirin 325 mg was also cost-effective if the initial rates decreased by an ARR 0.02% (NNT = 5807). Likewise, warfarin (5 mg) was cost-effective at all initial rates with an ARR of 0.02% (NNT = 4480). In contrast, enoxaparin (40 mg) and rivaroxaban (20 mg) were only cost-effective at higher initial symptomatic VTE rates with ARRs of 1.48% (NNT = 68) and 5.36% (NNT = 19). Additional analyses demonstrated that enoxaparin (40 mg) and rivaroxaban (20 mg) become cost-effective when costs of treating a symptomatic VTE are higher than our estimates. CONCLUSION: Chemoprophylaxis following TAA can be cost-effective. A tailored approach to VTE prophylaxis with cost-effectiveness in mind may be beneficial to the patient and health system.

Achilles Tendon Ruptures and Repair in Athletes-a Review of Sports-Related Achilles Injuries and Return to Play.

PURPOSE OF REVIEW: Achilles tendon ruptures (ATR) are detrimental to sports performance, and optimal treatment strategy and guidelines on return to play (RTP) remain controversial. This current review investigates the recent literature surrounding nonoperative versus operative management of ATR, clinical outcomes, and operative techniques to allow the athlete a successful return to their respective sport. RECENT FINDINGS: The Achilles tendon (AT) is crucial to the athlete, as it is essential for explosive activities such as running and jumping. Athletes that sustain an ATR play in fewer games and perform at a lower level of play compared to age-matched controls. Recent studies also theorize that ATRs occur due to elongation of the tendon with fatigue failure. Biomechanical studies have focused on comparing modes of fixation under dynamic loading to recreate this mechanism. ATRs can be career-ending injuries. Fortunately, the recent incorporation of early weight-bearing and functional rehabilitation programming for non-operative and operative patients alike proves to be beneficial. Especially for those treated nonoperatively, with the incorporation of functional rehabilitation, the risk of re-rupture among non-operative patients is beginning to approach the historical lower risk of re-rupture observed among patients treated operatively. Despite this progress in decreasing risk of re-rupture particularly among non-operative patients, operative managements are associated with unique benefits that may be of particular interest for athletes and active individuals. Recent studies demonstrate that operative intervention improves strength and functional outcomes with more efficacy compared to nonoperative management with rehabilitation. The current literature supports operative intervention in elite athletes to improve performance and shorten the duration to RTP. However, we acknowledge that surgical intervention does have inherent risks. Ultimately, most if not all young and/or high-level athletes with an ATR benefit from surgical repair, but it is crucial to take a stepwise algorithmic approach and consider other factors, which may lead towards nonoperative intervention. These factors include age, chronicity of injury, gap of ATR, social factors, and medical history amongst others in this review.

Opioid Use, Perioperative Risks, and Associated Postoperative Complications in Foot and Ankle Surgery.

INTRODUCTION: Opioid abuse has become a national crisis. Published data demonstrate that patients undergoing foot and ankle surgery are left with excess narcotic medications postoperatively. The purpose of our study was to evaluate factors associated with prolonged postoperative opioid use following foot and ankle surgery and identify associations between preoperative opioid use and postoperative complications. METHODS: MarketScan commercial claims and encounters database was searched to identify foot and ankle patients. Preoperative comorbidities were queried and documented. Patients utilizing opioids 1 to 3 months prior to surgery were identified. Adjusted odds ratios and 95% CIs were calculated using multivariable logistic regression to determine associations between opioid use (preoperatively and postoperatively), readmission, and complications. RESULTS: A total of 112 893 patients were included in the study. Preoperative use had a statistically significant association with postoperative use out to 1 year. Tobacco use, chronic pain, mental health diagnosis, and nonopioid medications had a statistically significant association with postoperative use. Preoperative opioid use had a statistically significant association with readmission and postoperative complications. CONCLUSION: Our study found a number of factors associated with prolonged postoperative opioid use (preoperative use, tobacco use, chronic pain, mental health disorders, and certain nonopioid medications). We identified an association between preoperative opioid use and postoperative complications and readmission. LEVELS OF EVIDENCE: Prognostic Level IV Evidence.

Utility and Associated Charge of Anteroposterior Radiographs in Rotational Ankle Fractures During Postoperative Follow-Up: The Results of an Orthopaedic Trauma Association Survey.

OBJECTIVES: To evaluate the perceived utility and associated charges of the anteroposterior (AP) radiograph during rotational ankle fracture postoperative follow-up. DESIGN: Survey study with charge analysis using published data at 50 orthopaedic hospitals in the United States. SETTING: Not Applicable. PARTICIPANTS: Orthopaedic Trauma Association Members with an active email address who were invited and interested in answering a survey. RESULTS: Ninety-four percent of respondents stated that they did routinely obtain an AP radiograph during rotational ankle fracture follow-up. However, 57% thought that the AP view should be eliminated from standard follow-up and only 51% found this view useful after initial treatment. CHARGE ANALYSIS: The mean difference between a 2-view and 3-view ankle radiograph series was $102.00. Using this value and the assumption that each patient with a rotational ankle fracture gets 3 follow-up radiographs, there is the potential for a charge reduction of $306 per patient. Assuming over 134,000 rotational ankle fractures, a charge reduction of 41 million US dollars (USD) per year is possible if the AP image is routinely removed. Actual savings are likely to be less based on agreed on payer rates. Although less easy to quantify, there is also a potential reduction of radiation exposure, radiologists' interpretation time, and data storage. CONCLUSIONS: Routine AP radiographs should potentially be eliminated from routine postoperative ankle x-ray protocols based on this survey of experienced orthopaedic surgeons. If this specific radiograph is ordered on a case-by-case basis, then significant savings may occur.

Animal model detects early pathologic changes of Charcot neuropathic arthropathy.

Charcot neuropathic arthropathy is a degenerative, debilitating disease that affects the foot and ankle in patients with diabetes and peripheral neuropathy, often resulting in destruction, amputation. Proposed etiologies include neurotraumatic, inflammatory, and neurovascular. There has been no previous animal model for Charcot. This study proposes a novel rodent model of induced neuropathic arthropathy to understand the earliest progressive pathologic changes of human Charcot. High-fat-diet-induced obese (DIO) Wild-type C57BL/6J mice (n = 8, diabetic) and age-matched low-fat-diet controls (n = 6) were run on an inclined high-intensity treadmill protocol four times per week for 7 weeks to induce mechanical neurotrauma to the hind-paw, creating Charcot neuropathic arthropathy. Sensory function and radiologic correlation were assessed; animals were sacrificed to evaluate hindpaw soft tissue and joint pathology. With this model, Charcot-DIO mice reveals early pathologic features of Charcot neuropathic arthropathy, a distinctive subchondral microfracture callus, perichondral/subchondral osseous hypertrophy/osteosclerosis, that precedes fragmentation/destruction observed in human surgical pathology specimens. There is intraneural vacuolar-myxoid change and arteriolosclerosis. The DIO mice demonstrated significant hot plate sensory neuropathy compared (P < 0.01), radiographic collapse of the longitudinal arch in DIO mice (P < 0.001), and diminished bone density in DIO, compared with normal controls. Despite exercise, high-fat-DIO mice increased body weight and percentage of body fat (P < 0.001). This murine model of diet-induced obesity and peripheral neuropathy, combined with repetitive mechanical trauma, simulates the earliest changes observed in human Charcot neuropathic arthropathy, of vasculopathic-neuropathic etiology. An understanding of early pathophysiology may assist early diagnosis and intervention and reduce patient morbidity and mortality in Charcot neuropathic arthropathy.

Biomechanical Effects of Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD), the Major Constituents of Cannabis, in a Sprague Dawley Rat Achilles Tendon Surgical Repair Model: A Pilot Study.

BACKGROUND: The use of cannabis is common among athletes and the US population at large. Cannabinoids are currently being evaluated as alternatives to opioid medications for chronic pain management. However, the effects of recreational and/or medical use of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on musculoskeletal injury and healing remain largely unknown. HYPOTHESIS/PURPOSE: The purpose of this study was to evaluate the biomechanical effects of CBD and THC on tendon-to-tendon healing in a rat Achilles tendon repair model. The hypothesis was that rats administered CBD would demonstrate decreased tensile load to failure of surgically repaired Achilles tendons compared with the THC and control groups. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 33 Sprague Dawley rats underwent Achilles tendon surgical transection and repair and were randomized to receive subcutaneous injection of THC, CBD, or vehicle once daily starting on the day of surgery and for 5 total days. After sacrifice, biomechanical tensile load-displacement testing was performed to determine Achilles tendon load to failure and stiffness. Data were analyzed by 1-way analysis of variance. RESULTS: The THC group demonstrated the highest median load to failure, 18.7 N (95% CI, 15.3-19.2 N); the CBD group had the second highest at 16.9 N (95% CI, 15.1-19.8 N), and the control group had the lowest at 14.4 N (95% CI, 12.1-18.3 N). Stiffness was highest in the THC group at 4.1 N/mm (95% CI, 2.7-5.1 N/mm) compared with 3.6 N/mm (95% CI, 2.9-4.1 N/mm) for the CBD group and 3.6 N/mm (95% CI, 2.8-4.3 N/mm) for the control group. No statistically significant differences for strength and stiffness were observed between the groups. CONCLUSION: In this pilot study using an animal tendon-to-tendon repair model, neither THC nor CBD resulted in altered biomechanical characteristics compared to control. CLINICAL RELEVANCE: Cannabinoids do not appear to adversely affect Achilles tendon healing.

Nicotine Exposure Via Electronic Cigarettes Significantly Impedes Biomechanical Healing Properties of Tendon Healing in a Rat Model.

PURPOSE: To evaluate the biomechanical and histologic effects on Achilles tendon repair of inhaled combusted tobacco versus nicotine exposure via electronic cigarette versus a control group in a small-animal model (Sprague-Dawley rat). METHODS: Fifty-four Sprague-Dawley rats were randomized into 3 groups: combusted tobacco, e-cigarettes, or control. Experimental rats were exposed to research cigarettes or e-cigarette vapor in a smoking chamber for 4 weeks. Surgical transection and repair of the Achilles tendon were then completed, followed by 2 additional weeks of exposure. Achilles tendons were harvested, and biomechanical tensile testing was performed. Histologic evaluation was completed, including hematoxylin-eosin staining, trichrome staining, and immunohistochemistry analysis for type I and type III collagen. RESULTS: The control group showed the highest mean tensile load to failure, at 41.0 ± 10.4 N (range, 18.3-55.1 N); the cigarette cohort had the second highest mean, at 37.3 ± 11.1 N (range, 14.0-54.7 N); and finally, the vaping group had the lowest mean, at 32.3 ± 8.4 N (range, 17.8-45.1 N). One-way analysis of variance showed a significant difference in load to failure when comparing the control group with the e-cigarette group (P = .026). No statistical difference was detected between the control group and cigarette group (P = .35) or between the e-cigarette group and cigarette group (P = .23). Stiffness and qualitative histologic analysis showed no difference among groups. CONCLUSIONS: This investigation shows that in a rat model, nicotine exposure via e-cigarette significantly impedes the biomechanical healing properties of Achilles tendon surgical repair. CLINICAL RELEVANCE: The results indicate that although e-cigarettes are often used as a perceived "safer" alternative to smoking, their use may have a detrimental effect on tendon load to failure.

Biomechanical Comparison of Fibertape Device Repair Techniques of Ligamentous Lisfranc Injury in a Cadaveric Model.

BACKGROUND: Lisfranc ligamentous injuries are complex, and their treatment, along with the preferred method of fixation, is controversial. Implementing a flexible synthetic augmentation device (fibertape) has been described as an alternative to traditional screw fixation. This biomechanical study evaluated two fibertape devices with interference screw fixation: InternalBrace, and InternalBrace with supplementary intercuneiform stabilization. METHODS: The diastasis and relative angular displacement between bones were measured at three midfoot joints in the Lisfranc articulation. Measurements were obtained for the pre-injured, injured, and post-fixation stages under static loading. Specimens then underwent stepwise increases in cyclic loading performed at 1 Hz and 100 cycles, at 100 N ground reaction force intervals from 500 to 1200 N to simulate postoperative loading, and then up to 1800 N to simulate high loads. Failure of fixation was defined as diastasis greater than 2 millimeters at the second-metatarsal - medial-cuneiform joint. RESULTS: InternalBrace specimens demonstrated failures in 3 of 9 (33%) specimens at cyclic loads of 1000 N. Conversely, InternalBrace with Supplementary Limb specimens had 1 failure at 1200 N. The difference in diastasis at the second metatarsal-medial cuneiform joint was statistically significant between the two groups at higher loads of 1600N (p = 0.019) and 1800N (p = 0.029). CONCLUSION: The use of InternalBrace for ligamentous Lisfranc injuries appears to provide a biomechanically viable alternative for withstanding early postoperative protected weight bearing. Furthermore, the use of a supplementary limb in addition to the InternalBrace fibertape fixation method appears to enhance its biomechanical efficacy.

Identification of long-range ultrasonic guided wave characteristics in cortical bone by modelling.

The propagation of ultrasonic guided waves in cortical bone has potential to inform medical caregivers about the condition of the bone structure. However, as waveguides, human long bones such as the tibia are complex in terms of their material behavior and their geometric features. They exhibit anisotropic elasticity and internal damping. For the first time, wave propagation is modelled in the irregular hollow tibial cross-section, which varies along its long axis. Semi-analytical, frequency domain, and time domain finite element analyses providing complimentary information about long-range wave propagation characteristics in such a waveguide are applied to the mid-diaphyseal region of a human tibia. Simulating the guided waves generated by a contact transducer, the signals received in axial transmission indicate the consistent presence of low phase velocity non-dispersive propagating modes. The guided waves capable of traveling long distances have strong potential for diagnosis of fracture healing.

Comparing the Efficacy of True-Volume Analysis Using Magnetic Resonance Imaging With Computerized Tomography and Conventional Methods of Evaluation in Cystic Osteochondral Lesions of the Talus: A Pilot Study.

Background: Osteochondral lesions of the talus (OLT) often require advanced imaging if they prove to be refractory to preliminary microfracture. Orthopedic surgeons may misinterpret the size and morphology of the OLT when evaluating through conventional methods. The purpose of this study was to evaluate MRI as a modality for calculating true-volumes and compare its utility to that of CT true-volume and conventional methods of measuring lesion size. METHODS: With IRB approval, an institutional radiology database was queried for patients with cystic OLT that had undergone and failed microfracture and had compatible CT and MR scans between 2011 and 2016. Five lesions, previously analyzed and described in the literature using CT true-volume, were selected. 10 orthopedic surgeons independently estimated the volume of these 5 OLT via standard MRI. Next, 3D reconstructions were created and morphometric true-volume (MTV) analysis measurements of each OLT were generated. The percent change in volumes from CT and MR was compared based upon MTVs determined from 3D reconstructive analysis. RESULTS: The volume calculated using conventional methods in CT and MR scans grossly overestimated the size by of the OLT by 285-864% and 56-374% respectively when compared to 3D true-volume analysis of those CT and MR scans. CONCLUSIONS: This study demonstrates that true-volume is more accurate for calculating lesion size than conventional methods. Additionally, when comparing MRI and CT, thin slice CT true-volume is superior to MRI true-volume. True-volume calculation improves accuracy with CT and MRI and should be recommended for use in revision OLT cases.Levels of Evidence: Level III: Case control study.