Venous Thromboembolism in Outpatient Elective Foot and Ankle Procedure Patients Who Is at Risk?

BACKGROUND: Venous thromboembolism (VTE) is a rare but potentially serious complication following elective foot and ankle (F&A) procedures. The absence of guidelines for thromboprophylaxis in elective procedures underscores the importance of identifying patients at risk. This study aimed to identify key risk factors of VTE in patients who underwent elective foot and ankle (F&A) operations. METHODS: Data was collected from the IBM MarketScan Database (2009-2019) for patients >18 years old without prior VTE who underwent elective F&A procedures. Patients were divided into 3 groups based on region of operation (forefoot, mid/hindfoot, lower leg/ankle). VTE incidence (including deep vein thrombosis and/or pulmonary embolism) was recorded 30 and 90 days postprocedure. Risk factors for VTE were identified through multivariate logistic regression. RESULTS: Among the 301 256 patients who underwent elective F&A procedures, the overall 90-day incidence of VTE was 0.95%. The findings revealed that 31.9% of VTE incidents occurred within the first 2 weeks after operation, and 29.2% still occurred after 6 weeks. Analysis of the anatomical region of operation demonstrated that the lowest rate of 90-day VTE was amongst patients undergoing forefoot procedures (0.70%). There was a higher risk for VTE in patients undergoing midfoot/hindfoot procedures (1.22%, OR = 1.81) and lower leg/ankle procedures (1.76%, OR = 2.31). Additional risk factors for VTE included thrombophilia (4.02%, OR = 3.37), male sex (1.30%, OR = 1.47), increasing age (1.02% age 65+, OR = 1.41), and a high Charlson Comorbidity Index (1.12%, OR < 0.82 for scores <5). CONCLUSION: This study identifies the incidence and timing for VTE after elective F&A procedures. Furthermore, this study defines the risk factors associated with increased odds of VTE after elective F&A procedures. These findings are helpful in educating patients about a continued risk for VTE throughout the 90-day postoperative period and beyond. These results can also be utilized to stratify patients who need thromboprophylaxis based on the individual risk level. LEVEL OF EVIDENCE: Level III: Retrospective cohort study.

Lateral Ankle Ligament Repair Is Not Only for Young Patients: Trends in Incidence and Demographics.

The purpose of this study was to examine the changes in annual incidence and patient population undergoing lateral ankle ligament repair (LALR) for the surgical treatment of chronic ankle instability. The IBM Watson Health MarketScan Database was queried for patients who underwent LALR from January 2009 to December 2019 based on CPT code 27698. Volume and incidence per 100 000 population were determined for annual sums, gender, age, and geographical regions based on population estimates from the United States Census Bureau. Future annual volumes were statistically projected with linear regression modeling to the year 2032. Overall, 160 457 LALR procedures were identified in the database from 2009 to 2019. Annual incidence increased 76.6% from 3.46 to 6.11 cases per 100 000 population, while estimates of annual volumes are projected to increase 61.5% from 19 829 to 32 033 procedures to the year 2032. Interestingly, the greatest increase in incidence was observed among patients above 70 years old, which might suggest older patients are staying active longer and desiring elective procedures to maintain their activity levels. As the incidence of LALR increases in older patients, more research will be needed to understand the unique surgical considerations and risk factors impacting patient-reported outcomes.Level of Evidence: Level IV.

Weightbearing Computed Tomography Can Accurately Detect Subtle Lisfranc Injury.

BACKGROUND: Early detection of Lisfranc injury is critical for improving clinical outcomes, but diagnosing subtle injury can be difficult. Weightbearing computed tomography (WBCT) allows evaluation of such injuries in 3 dimensions (3D) under physiologic load. This study aimed to assess the utility of 1-, 2-, and 3-dimensional measurements on WBCT to diagnose subtle injury in isolated ligamentous Lisfranc injuries. METHODS: Ten cadaveric specimens underwent WBCT evaluation of the Lisfranc joint complex in the intact state and subsequently with sequential sectioning of the dorsal Lisfranc ligament and interosseous Lisfranc ligament (IOL) to create subtle Lisfranc injury, and finally after transectioning of plantar Lisfranc ligament (PLL) to create the injury conditions for complete ligamentous Lisfranc injury. Measurements under static vertical tibial load of 80 kg were performed on WBCT images including (1) Lisfranc joint (medial cuneiform-base of second metatarsal) volume, (2) Lisfranc joint area, (3) C1-C2 intercuneiform area, (4) C1-M2 distance, (5) C1-C2 distance, (6) M1-M2 intermetatarsal distance, (7) first tarsometatarsal (TMT1) alignment, (8) second tarsometatarsal (TMT2) alignment, (9) TMT1 dorsal step-off distance, and (10) TMT2 dorsal step-off distance. RESULTS: In the subtle Lisfranc injury state, Lisfranc joint volume and area, C1-M2 distance, and M1-M2 distance measurements on WBCT significantly increased, when compared with the intact state (P values .001 to .014). Additionally, Lisfranc joint volume and area, C1-M2 distance, M1-M2 distance, TMT2 alignment, and TMT2 dorsal step-off measurements were increased in the complete Lisfranc injury state. Of all measurements, C1-M2 distance had the largest area under the curve (AUC) of 0.96 (sensitivity = 90%; specificity = 90%), followed by Lisfranc volume (AUC = 0.90; sensitivity = 80%; specificity = 80%) and Lisfranc area (AUC = 0.89; sensitivity = 80%; specificity = 100%). CONCLUSION: In a cadaveric model we found that WBCT scan can increase the diagnostic accuracy for subtle Lisfranc injury. Among the measurements, C1-M2 distance exhibited the highest level of accuracy. The 2D joint area and 3D joint volume also proved to be accurate, with 3D volume measurements of the Lisfranc joint displaying the most significant absolute difference between the intact state and increasing severity of Lisfranc injury. These findings suggest that 2D joint area and 3D joint volume may have potential as supplementary measurements to more accurately diagnose subtle Lisfranc injuries. CLINICAL RELEVANCE: WBCT may help surgeons detect subtle Lisfranc injuries.

3D kinematics of tibiotalar motion in patients with mobile bearing and fixed bearing total ankle arthroplasty: In vivo videofluoroscopic feasibility study.

BACKGROUND: As total ankle arthroplasty (TAA) is an increasingly common surgical intervention for patients with end-stage ankle arthritis, there is a need to better understand the dynamic performance of prosthetic implants during activities of daily living. Our purpose was to quantify and compare relative tibiotalar motion during gait in persons with a fixed-bearing (FB) and mobile-bearing (MB) total ankle arthroplasty. We hypothesized a FB prosthesis would have lower tibiotalar range of motion (ROM). METHODS: Patients at least 12 months postoperative with either a FB (n=5) or MB (n=3) total ankle arthroplasty were tested. We used high-speed biplanar videoradiography to quantify tibiotalar kinematics during self-selected gait. Angular and linear ROM in three axes were compared between the groups. RESULTS: ROM for dorsiflexion-plantarflexion, internal-external rotation, and inversion-eversion angles in FB subjects averaged 7.47±4.05°, 7.39±3.63°, and 4.51±2.13°, respectively. ROM in MB subjects averaged 6.74±2.04°, 6.28±4.51°, and 5.68±2.81°, respectively. Linear ROM along anteroposterior, mediolateral, and superior-inferior axes in FB subjects averaged 1.47±2.07 mm, 1.13±1.49 mm, and 0.28±0.30 mm, respectively. Linear ROM in MB subjects averaged 0.68±1.44 mm, 0.60±1.41 mm, and 0.20±0.13 mm, respectively. We found no significant difference between the two groups for any of these ROM parameters (p>0.05). CONCLUSION: Total ankle arthroplasty using either FB or MB design appears to confer similar ankle motion during the gait cycle in this biplanar fluoroscopic model. LEVEL OF EVIDENCE: Level IV, case series.

Body Mass Index (BMI) Cutoffs and Racial, Ethnic, Sex, or Age Disparities in Patients Treated With Total Ankle Arthroplasty.

Background: The rising prevalence of obesity among American adults has disproportionately affected Black adults and women. Furthermore, body mass index (BMI) has historically been used as a relative contraindication to many total joint arthroplasty (TJA) procedures, including total ankle arthroplasty. The purpose of this study was to investigate potential disparities in patient eligibility for total ankle arthroplasty based on race, ethnicity, sex, and age by applying commonly used BMI cutoffs to the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Methods: Patients in the ACS-NSQIP database who underwent TAA from 2011 to 2020 were retrospectively reviewed in a cross-sectional analysis. BMI cutoffs of <50, <45, <40, and <35 were then applied. The eligibility rate for TAA was examined for each BMI cutoff, and findings were stratified by race, ethnicity, sex, and age. Independent t tests, chi-squared tests, and Fisher exact tests were performed to compare differences at an α = 0.05. Results: A total of 1215 of 1865 TAA patients (65.1%) were included after applying the exclusion criteria. Black patients had disproportionately lower rates of eligibility at the most stringent BMI cutoff of <35 (P = .004). Hispanic patients had generally lower rates of eligibility across all BMI cutoffs. In contrast, Asian American and Pacific Islander patients had higher rates of eligibility at the BMI cutoffs of <35 (P = .033) and <40 (P = .039), and White non-Hispanic patients had higher rates of eligibility across all BMI cutoffs. Females had lower eligibility rates across all BMI cutoffs. Ineligible patients were also younger compared to eligible patients across all BMI cutoffs. Conclusion: Stringent BMI cutoffs may disproportionately disqualify Black, female, and younger patients from receiving total ankle arthroplasty. Level of Evidence: Level III, retrospective cross-sectional study.

Risk Factors for Prolonged Opioid Use After Ankle Fracture Surgery.

BACKGROUND: The incidence of ankle fractures is increasing, and risk factors for prolonged opioid use after ankle fracture fixation are unknown. Accordingly, the purpose of this study was to investigate risk factors that lead to prolonged opioid use after surgery. METHODS: The Truven MarketScan database was used to identify patients who underwent ankle fracture surgery from January 2009 to December 2018 based on CPT codes. Patient characteristics were collected, and patients separated into 3 cohorts based on postoperative opioid use (no refills, refills within 6 months postoperative, and refills within 1 year postoperatively). The χ2 test and multivariate analysis were performed to assess the association between risk factors and prolonged use. RESULTS: In total, 34 691 patients were analyzed. Comorbidities most highly associated with prolonged opioid use include 2+ preoperative opioid prescriptions (odds ratio [OR] = 11.92; P < .001), tobacco use (OR = 2.03; P < .001), low back pain (OR = 1.81; P < .001), depression (OR = 1.48; P < .001), diabetes (OR = 1.34; P < .001), and alcohol abuse (OR = 1.32; P < .001). CONCLUSION: Opioid use after ankle fracture surgery is common and may be necessary; however, prolonged opioid use and development of dependence carries significant risk. Identifying those patients at an increased risk for prolonged opioid use can aid providers in tailoring their postoperative pain regimen. LEVELS OF EVIDENCE: Prognostic, Level III.

Effect of Obesity on Patient-Perceived Outcomes After First Metatarsophalangeal Joint Arthrodesis.

BACKGROUND: While first metatarsophalangeal joint (MTPJ) arthrodesis is a common and effective procedure, there is a paucity of studies examining obesity's effect on outcomes of 1st MTPJ arthrodesis. This study's purpose was to evaluate patient-reported outcomes following 1st MTPJ arthrodesis in obese versus non-obese patients. METHODS: A retrospective cohort study of 94 patients undergoing first MTPJ fusion over the age of 18 with a diagnosis of hallux valgus or hallux rigidus was performed. Surgical and postoperative outcomes were examined preoperatively and at 6 and 12 months follow-up via Visual Analog Pain scale (VAS), and Short Form 36 (SF-36) surveys, and data were stratified into 2 patient groups: BMI < 30 (n = 62, mean age 63.9 ± 9.1 and ≥ 30 (n = 32, mean age 61.9 ± 8.4). RESULTS: Average overall VAS and SF-36 physical component scores improved significantly at 6 months (P < .001, .006) and 1 year postoperative visits (P < .001, .007) with no differences in survey scores, outcomes, or complications between weight groups. CONCLUSION: Our study showed first MTPJ fusion improves short-term pain and physical quality-of-life in arthritic obese and non-obese patients without differences in nonunion, complications, or patient-reported measures. LEVEL OF EVIDENCE: Level III, Prognostic, Case-Control Study.

The Rise of Total Ankle Arthroplasty Use: A Database Analysis Describing Case Volumes and Incidence Trends in the United States Between 2009 and 2019.

BACKGROUND: Ankle arthrodesis has been the mainstay treatment for end-stage ankle arthritis. The popularity of total ankle arthroplasty (TAA) has been on the rise due to improved implant design and postoperative outcomes. The purpose of this study was to describe the basic epidemiology and trends of annual procedure volumes and incidence in the general American population as well as in different population subgroups from 2009 to 2019. We hypothesize that the incidence of TAA has significantly risen while the median length of hospital stay has decreased nationwide. METHODS: The IBM MarketScan database was queried for patients who underwent TAA from January 2009 to December 2019 based on Current Procedural Terminology coding. Population estimates from the US Census Bureau were used to calculate the annual incidence of TAA. Procedural volume and incidence were calculated for annual sums, gender, age subgroups, inpatient and outpatient TAA, as well as in four statistical geographic regions in the United States. Median length of hospital stay was calculated and trended annually for inpatient TAA. RESULTS: A total of 41,060 primary TAAs were identified in the database from 2009 to 2019, in which 52.5% were performed in males. Annual volumes increased by 136.1%, from 2180 to 5147 procedures nationwide. Incidence reported per 100 000 population increased by 120.8%. Both inpatient and outpatient procedures have increased, by 242.5% and 86.6%, respectively. Median length of hospital stay decreased from 3 days in 2009 to 1 day in 2019 and did not differ between genders. Growth in incidence was demonstrated in males and females above the age of 54 years with the largest growth in annual incidence found between 65 and 74 years. Incidence rose in the South and West of the United States by 111.8% and 136.5%, respectively. CONCLUSION: We found that annual volumes and incidence rates of primary TAA has increased between 2009 and 2019. Although both inpatient and outpatient surgery have become more frequent, inpatient volumes and incidence have increased almost 3 times more than those of outpatient surgery. Length of hospital stay decreased over the study years. When adjusted for the same study period, the cumulative annual growth rates of TAA were found to be 2 times greater than total knee arthroplasty and 3.6 times greater than total hip arthroplasty. LEVEL OF EVIDENCE: Level III, retrospective database review.

Projections and Epidemiology of Total Ankle and Revision Total Ankle Arthroplasty in the United States to 2030.

Background: Total ankle arthroplasty (TAA) utilization is increasing in the United States. As the incidence of this procedure grows, it is important for providers to understand the future projections for ankle arthroplasty and more importantly revision total ankle arthroplasty (rTAA). Methods: The National Inpatient Sample (USA) was queried from 2005 to 2017 for all TAA and rTAA. Poisson and linear regression analysis was performed to project annual incidence of TAA and rTAA to 2030, with subgroup analyses on septic rTAA. Results: There were 5315 TAAs performed in 2017, a 564% (P < .001) increase when compared with the TAAs performed in 2005. From 2017 to 2030, the incidence of TAAs is projected to increase from 110% to 796% (P < .001). There were 1170 rTAAs performed in 2017, a 155% (P < .001) increase when compared with rTAAs performed in 2005. There was a 256% increase in the incidence of septic rTAAs from 2005 to 2017 with a projected increase between 22% and 120% by 2030. Conclusions: The incidence of both TAAs and rTAAs is projected to significantly increase over the next decade. Given the known risk factors of TAA and rTAA, these findings reinforce the need for thoughtful consideration when selecting patients for TAA.

Preoperative Depression is Associated With Increased Complications Following Ankle Fracture Surgery.

BACKGROUND: The effects of preoperative depression following ankle fracture surgery remains unknown. The purpose of this study is to investigate the relationship between preoperative depression and outcomes following ankle fracture surgery. METHODS: This retrospective study used the Truven MarketScan database to identify patients who underwent ankle fracture surgery from January 2009 to December 2018. Patients with and without a diagnosis of preoperative depression were identified based on International Classification of Diseases (ICD) codes. Chi-squared and multivariate analyses were performed to determine the association between preoperative depression and postoperative complications following ankle fracture surgery. RESULTS: In total, 107,897 patients were identified for analysis, 13,981 of whom were diagnosed with depression (13%). Preoperative depression was associated with the increased odds for postoperative infection (odds ratio [OR]: 1.33, confidence interval [CI]: 1.20-1.46), wound complications (OR: 1.13, CI: 1.00-1.28), pain-related postoperative emergency department visits (OR: 1.58, CI: 1.30-19.1), 30-day and 90-day readmissions (OR: 1.08, CI: 1.03-1.21 and OR: 1.13, CI: 1.07-1.18), sepsis (OR: 1.39, CI: 1.12-1.72), and postoperative development of complex regional pain syndrome (OR: 1.46, CI: 1.18-1.81). CONCLUSION: Preoperative depression is associated with increased complications following ankle fracture surgery. Further studies are warranted to investigate the degree to which depression is a modifiable risk factor. LEVEL OF EVIDENCE: 3.

Medical Malpractice Trends in Foot and Ankle Surgery.

Medical malpractice lawsuits can place significant economic and psychologic burden on a provider. Orthopedic surgery is one of the most common subspecialties involved in malpractice claims. There is currently no study examining malpractice lawsuits within foot and ankle surgery. Accordingly, the purpose of this work is to examine trends in malpractice claims in foot and ankle surgery. The Westlaw legal database was queried for lawsuits pertaining to foot and ankle surgery from 2008 to 2018. Only cases involving medical malpractice were included for analysis. All available details pertaining to the cases were collected. This included plaintiff demographic and geographic data. Details regarding the cases were also collected such as anatomical location, pathology, complications, and case outcomes. Forty-nine malpractice lawsuits pertaining to foot and ankle were identified. Most plaintiffs in these cases were adult females, and the majority of cases occurred in the northeast (53.1%). The most common anatomical region involved in claims involved the forefoot (29%). The majority of these claims involved surgery (65%). Infection was the most common complication seen in claims (22%). The jury ruled in favor of the defendant surgeon in most cases (73%). This is the first study to examine trends in medical malpractice within foot and ankle surgery. Infection was the most frequent complication seen in claims and forefoot surgery was the most common anatomic location. A large portion of claims resulted after nonoperative treatment. A better understanding of the trends within malpractice claims is crucial to developing strategies for prevention.

Three-dimensional Printing in Orthopaedic Surgery: Current Applications and Future Developments.

Three-dimensional (3D) printing is an exciting form of manufacturing technology that has transformed the way we can treat various medical pathologies. Also known as additive manufacturing, 3D printing fuses materials together in a layer-by-layer fashion to construct a final 3D product. This technology allows flexibility in the design process and enables efficient production of both off-the-shelf and personalized medical products that accommodate patient needs better than traditional manufacturing processes. In the field of orthopaedic surgery, 3D printing implants and instrumentation can be used to address a variety of pathologies that would otherwise be challenging to manage with products made from traditional subtractive manufacturing. Furthermore, 3D bioprinting has significantly impacted bone and cartilage restoration procedures and has the potential to completely transform how we treat patients with debilitating musculoskeletal injuries. Although costs can be high, as technology advances, the economics of 3D printing will improve, especially as the benefits of this technology have clearly been demonstrated in both orthopaedic surgery and medicine as a whole. This review outlines the basics of 3D printing technology and its current applications in orthopaedic surgery and ends with a brief summary of 3D bioprinting and its potential future impact.

Avascular Necrosis of the Talus.

Talar osteonecrosis results from trauma to the fragile blood supply to the talus. Many etiologies exist that can cause talar osteonecrosis, with the most common being talar neck fractures. Patients with talar osteonecrosis frequently present with progressive ankle pain and limited range of motion. Treatment strategy depends primarily on the stage of disease. Conservative care in the form of medications and bracing treatment can be beneficial for patients with low functional status and early disease stages. Surgical options also exist for early disease without talar collapse that can potentially preserve the tibiotalar joint. Once talar collapse develops, surgical treatment is move invasive and typically involves an arthrodesis or talus arthroplasty. Although some treatment guidelines exist based on the disease stage, talar osteonecrosis is a complex problem, and treatment strategy should always be determined on a case-by-case basis carefully examining all clinical aspects.

From Patient to Procedure: The Process of Creating a Custom 3D-Printed Medical Device for Foot and Ankle Pathology.

Three-dimensional (3D) printing technology has advanced greatly over the past decade and is being used extensively throughout the field of medicine. Several orthopaedic surgery specialties have demonstrated that 3D printing technology can improve patient care and physician education. Foot and ankle pathology can be complex as the 3D anatomy can be challenging to appreciate. Deformity can occur in several planes simultaneously and bone defects either from previous surgery or trauma can further complicate surgical correction. Three-dimensional printing technology provides an avenue to tackle the challenges associated with complex foot and ankle pathology. A basic understanding of how these implants are designed and made is important for surgeons as this technology is becoming more widespread and the clinical applications continue to grow within foot and ankle surgery.Levels of Evidence: Level V.

Clinical applications of custom 3D printed implants in complex lower extremity reconstruction.

BACKGROUND: Three dimensional printing has greatly advanced over the past decade and has made an impact in several industries. Within the field of orthopaedic surgery, this technology has vastly improved education and advanced patient care by providing innovating tools to complex clinical problems. Anatomic models are frequently used for physician education and preoperative planning, and custom instrumentation can assist in complex surgical cases. Foot and ankle reconstruction is often complicated by multiplanar deformity and bone loss. 3D printing technology offers solutions to these complex cases with customized implants that conform to anatomy and patient specific instrumentation that enables precise deformity correction. CASE PRESENTATION: The authors present four cases of complex lower extremity reconstruction involving segmental bone loss and deformity - failed total ankle arthroplasty, talus avascular necrosis, ballistic trauma, and nonunion of a tibial osteotomy. Traditional operative management is challenging in these cases and there are high complication rates. Each case presents a unique clinical scenario for which 3D printing technology allows for innovative solutions. CONCLUSIONS: 3D printing is becoming more widespread within orthopaedic surgery. This technology provides surgeons with tools to better tackle some of the more challenging clinical cases especially within the field of foot and ankle surgery.

3D Printed Total Talus Replacement for Avascular Necrosis of the Talus.

BACKGROUND: Talus avascular necrosis (AVN) is a challenging entity to treat. Management options depend on disease severity and functional goals. Total talus replacement (TTR) is a treatment option that maintains joint range of motion. The literature on TTR is limited with variability in implant design and material. The purpose of this study was to evaluate outcomes following TTR with a custom 3D printed metal implant. METHODS: Patients who underwent TTR were retrospectively reviewed over a 3-year period. Basic demographic data and comorbidities were collected. Medical records were reviewed to obtain postoperative and preoperative visual analog scale (VAS) scores, Foot and Ankle Outcome Scores (FAOSs), ankle range of motion, and postoperative complications. Statistical analysis was conducted to compare clinical and patient-reported outcomes pre- and postoperatively. Twenty-seven patients underwent TTR for talar AVN with a mean follow-up of 22.2 months. RESULTS: Ankle range of motion remained unchanged postoperatively. VAS pain scores improved postoperatively from 7.1 to 3.9 (P < .001). FAOSs improved postoperatively with regard to pain (P < .001), symptoms (P = .001), quality of life (P < .001), and activities of daily living (P < .001). There were 3 complications requiring reoperation in this cohort. CONCLUSION: 3D printed TTRs represent a unique surgical option for patients with severe talar AVN. Patients in this cohort demonstrated significant improvements in pain scores and patient-reported outcomes. TTR allows for symptomatic improvement with the preservation of motion in individuals with talar collapse and AVN. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparison of 3D Printed Spherical Implants versus Femoral Head Allografts for Tibiotalocalcaneal Arthrodesis.

Successful tibiotalocalcaneal (TTC) arthrodesis can be difficult to achieve in patients with bulk bone defects even with the use of femoral head allograft. Retrograde intramedullary nail placement through custom 3-dimensional (3D) spherical implants is an innovative option for these patients. The purpose of this study was to compare fusion rates, graft resorption, and complication rates between patients undergoing TTC fusion with 3D sphere implants versus femoral head allografts. Patients who underwent TTC arthrodesis with an intramedullary nail along with a 3D spherical implant (n = 8) or femoral head allograft (n = 7) were included in this study. The rate of successful fusion of the tibia, calcaneus, and talar neck to the 3D sphere or femoral head allograft was compared between the groups. The rate of total fused articulations was significantly higher in the 3D sphere group (92%) than the femoral head allograft group (62%; p = .018). The number of patients achieving successful fusion of all 3 articulations was higher in the 3D sphere group (75%) than the femoral head allograft group (42.9%, p = .22). The rate of graft resorption was significantly higher in the femoral head allograft group (57.1%) than the 3D sphere group (0%, p = .016). There were no significant differences between the groups in terms of complications. These data demonstrate that the use of a custom 3D printed sphere implant is safe in patients with severe bone loss undergoing TTC arthrodesis with a retrograde intramedullary nail and may result in improved rates of successful arthrodesis.

Biomechanical Effect on Joint Stability of Including Deltoid Ligament Repair in an Ankle Fracture Soft Tissue Injury Model With Deltoid and Syndesmotic Disruption.

BACKGROUND: The current operative standard of treatment for bimalleolar equivalent ankle fracture is open reduction and internal fixation (ORIF) of the lateral malleolus followed by syndesmotic stabilization if indicated. There is controversy surrounding the indication and need for deltoid ligament repair in this setting. The purpose of this study was to quantify the biomechanical effect of deltoid ligament repair in an ankle fracture soft tissue injury model. METHODS: Nine fresh-frozen cadaveric specimens were included in this study. Each leg was tested under 5 conditions: intact, syndesmosis and deltoid ligament sectioned, syndesmosis fixed, deltoid repaired, and both the syndesmosis and deltoid ligament repaired. Anterior, posterior, lateral, and medial drawer and rotational stresses were applied to the foot, and the resulting talus displacement was documented. RESULTS: Isolated deltoid repair significantly reduced anterior displacement to normal levels. Displacement with lateral drawer testing was not significantly corrected until both structures were repaired. Deltoid repair and syndesmosis fixation each reduced internal rotation significantly with further reduction to normal levels when both were repaired. External rotation remained elevated relative to the intact condition regardless of which structures were repaired. CONCLUSION: There is existing controversy regarding the importance of deltoid ligament repair in the setting of ankle fractures. The findings of this biomechanical study indicate that deltoid ligament repair enhances ankle stability in ankle fractures with both syndesmotic and deltoid disruption. CLINICAL RELEVANCE: Concomitant deltoid ligament repair in addition to stabilization of fracture and syndesmosis may improve long-term functioning of the ankle joint and clinical outcomes.

Development of a Small Animal Ankle Arthrodesis Model.

BACKGROUND: Our understanding of the biology of ankle arthrodesis is based largely on work in spine and long bone animal models. However, the local soft tissue and vascular anatomy of the foot and ankle is different from that of the spine. Accordingly, the objective of this study was to develop a small animal ankle arthrodesis model. METHODS: A total of 12 Lewis rats successfully underwent ankle arthrodesis with stabilization consisting of a single Kirschner wire across the prepared tibiotalar joint. Based on high nonunion rates with this initial procedure, a modification was made consisting of a second pin crossing the joint. A total of 6 rats underwent the second procedure. Radiographs were taken postoperatively and in 2-week intervals up to 10 weeks. Micro computed tomography (µCT) and histological analysis was conducted at 10 weeks to assess the fusion mass. Osseous bridging of greater than 50% across the tibiotalar joint was deemed a successful fusion. RESULTS: µCT analysis determined that 11 of the 12 rats in the single-pin cohort developed nonunions (8.3% fusion rate). In the dual-pin cohort, all 6 animals successfully fused (100% fusion rate). Histological analysis supported the radiographic imaging conclusions. CONCLUSION: While the initial procedure had a high nonunion rate, enhancing the stability of the fixation greatly increased the union rate. CLINICAL RELEVANCE: The present work demonstrates the first reliable small animal ankle arthrodesis model. We believe that this model can be used in the development of novel therapies aimed at decreasing complications and increasing fusion rates.

Impact of Vancomycin Treatment on Human Mesenchymal Stromal Cells During Osteogenic Differentiation.

BACKGROUND: Vancomycin is frequently applied locally to the operative site during foot and ankle procedures to help prevent infection. Although the efficacy of locally applied vancomycin has been demonstrated in spine surgery, there is no consensus on dosing and indication within foot and ankle surgery. Osteogenic differentiation of human mesenchymal stromal cells (hMSCs) is key to healing of both fractures and arthrodesis. The purpose of this research was to determine the impact of vancomycin on human hMSCs during the process of osteogenic differentiation. METHODS: hMSCs were cultured in osteogenic differentiation media to promote osteogenic differentiation. Cells were treated with vancomycin at differing concentrations of 0, 50, 500, and 5000 µg/mL. Viability and cell growth were assessed via LIVE/DEAD viability/cytotoxicity kit (Invitrogen, Waltham, MA) after 1, 3, and 7 days of vancomycin treatment. Differentiation and mineralization was assessed via alizarin red staining after 21 days of treatment. Mean cell viability, cell number, and mineralization were compared between treatment groups using 1-way analysis of variance and the Tukey-Kramer method for post hoc pairwise comparisons. RESULTS: At the highest concentrations of vancomycin, there was a significant reduction in cell viability and proliferation after 3 days compared with all other treatment groups. Mineralization was also significantly decreased with higher doses of vancomycin. CONCLUSION: At high concentrations, vancomycin may impair hMSC viability and osteogenic differentiation. CLINICAL RELEVANCE: Surgeons should exercise caution and consider the limited soft tissue envelope when applying vancomycin locally during foot and ankle surgery, especially during arthrodesis procedures.