Stress Fractures of the Foot and Ankle in Athletes

Stress fractures of the foot and ankle are common injuries in athletes. Management differs considerably based on fracture location and predisposing factors. Repetitive loading of the foot and ankle in athletes should result in physiologic bone remodeling in accordance with Wolff’s law. However, when there is not sufficient time for complete healing to occur before additional loads are incurred, this process can instead lead to stress fracture. Assessment of the athlete’s training regimen and overall bone health is paramount to both the discovery and treatment of these injuries, although diagnosis is often delayed in the setting of normal-appearing initial radiographs. While most stress fractures of the foot or ankle can usually be treated nonoperatively with a period of activity modification, fractures in certain locations are considered “high risk” due to poor intrinsic healing and may warrant more proactive operative management

Association between Socioeconomic Status and Increased Postoperative Emergency Department Utilization following Ankle Fracture Surgery

Category: Trauma; Ankle Introduction/Purpose: There is a paucity of literature regarding the effect of socioeconomic disparity on patient access to health care following surgery for acute musculoskeletal injuries. We hypothesized that lower socioeconomic status (SES) is independently associated with increased utilization of the emergency department (ED) for care, and less reliable outpatient follow up after ankle fracture surgery. Methods: A retrospective analysis was performed of 1,571 patients who underwent ankle fracture surgery between 2010 and 2020 at three large academic medical centers and one community hospital. Using 2010 United States Census data linked to place of residence, a summary measure of SES was created for each zip code. SES was divided into three percentile groups: 0-25%, 26-75% and 76-100%, wherein the 0- 25% group represented the lowest SES score. Independent patient and injury factors associated with ED visits and outpatient in-office follow up within 90 days of ankle fracture surgery were examined using multivariable Poisson regression models. Results: Patients in the lowest quintile of SES had a higher incidence of ED visits within 90 days after surgery (adjusted incidence ratio [aIR], 1.54, p< 0.001). Patients in the highest quintile of SES had a higher frequency of outpatient follow up within 90 days after surgery (aIR, 1.23, p< 0.001) compared to those in the middle SES quintile. Independent factors associated with increased ED visits following ankle fracture surgery were lower SES, lateral malleolus fracture, heightened comorbidities, increased BMI, Spanish-speaking patients, and patients with drug and/or alcohol dependence. Conclusion: Patients of lower socioeconomic status, those with substance use disorders, and those who must overcome language barriers to seek care demonstrate higher emergency resource utilization and are less likely to follow up in clinic after ankle fracture surgery. A better understanding of patient and injury factors associated with such increased ED visits may provide guidance as to which patient subpopulations may require more attention after ankle fracture surgery

Patient Comprehension of Foot and Ankle Surgery

Category: Other Introduction/Purpose: Health literacy represents a set of individual abilities which allow patients to assimilate information that helps them comprehend their medical condition and any interventions available for remedy. The purpose of this investigation was to determine the percentage of patients who— after undergoing the process of informed consent and being provided a postoperative instruction document—were then able to reach an elementary understanding of the pathology and requisite care associated with open reduction internal fixation of an ankle or foot fracture, osteotomy, fusion, or arthroscopy, including perioperative complications. Methods: Any patient who elected to have a foot or ankle surgical procedure that involved fracture, fusion, osteotomy, or arthroscopic management was recruited to participate in the study. Patients who were not deemed fluent in English were excluded. All patients were told that they would be asked to complete a questionnaire about their surgery and post-operative instructions. Enrolled patients were informed about the care and potential postoperative complications associated with their particular procedure during the informed consent process at the preoperative visit. All answers to each question of the questionnaire they would later receive were verbally given to each patient during this visit, and they were also given a post- operative instruction sheet that contained written answers to all these questions as well. At their first post-operative visit and prior to seeing the physician, all patients were then asked to complete this multiple choice questionnaire. The questionnaire was subsequently reviewed by the clinician with each patient at the end of this postoperative visit. Results: Forty-one patients were enrolled prospectively. Ninety percent (n=37) reported that they had read the postoperative instructions, and 92.7% (n=38) reported that they preferred a written handout versus a verbal, video, or on-line instructional alternative.. The average percentage of correct answers was 72.3% (7.95 out of 11 correct SD 1.4, 95% CI, 7.52 to 8.38). Only 43.9% (n=18) knew the correct response to ‘When can I return to driving an automatic vehicle?’. Only 53.7% (n=22) of patients knew ‘What is an appropriate protocol for icing immediately after surgery’. Chi square analysis of correct response count revealed no significant difference between patients with a high school versus higher level of education (p=0.22), males versus females (p=0.98), or age 18 to 30 versus over 30 years (p=0.59). Conclusion: Although we made significant pre-operative oral and written efforts to help patients achieve an elementary level of health literacy regarding their forthcoming foot or ankle surgery, we found that many continued to lack a baseline level of acceptable comprehension regarding numerous pertinent components of perioperative care and outcome. Because the results are concerning, we plan to next implement and test an alternative video aide to assess whether alternative forms of communication will increase comprehension and retention of surgical foot and ankle patients

Opioid Consumption Rate After Foot and Ankle Surgery

Category: Opioid consumption rate and risk factors investigation after foot and ankle surgery Introduction/Purpose: The rapid increase in the consumption of prescription opioids has become one of the leading medical, economical, and sociological burdens in North America. In the United States, orthopedic surgery is the fourth leading specialty in the number of opioids prescribed, and the largest among surgical specialties. There is insufficient evidence to guide surgeons about appropriate opioid prescription amounts after orthopaedic foot and ankle (F&A) procedures. The aim of this study was to determine the opioid consumption rate after foot and ankle procedures, and to identify patient risk factors associated with higher use. Methods: A total of 535 patients who underwent a F&A surgery performed by one orthopedic surgeon from August 2016 to March 2018 were investigated. The study was approved by our IRB. Each patient received a preoperative discussion about postoperative pain and expectations alongside a standardized handout. At the two-week postoperative visit, the patient-reported amount of consumed opioids was recorded. Prescription details, the amount of opioids taken, refill requests, pain-issue related telephone calls, and additional MD/ED visits were also documented. Patient demographics and co-morbidities, use of regional anesthesia, postoperative inpatient hospitalization, surgery type and severity, and pre-operative opioid use were collected retrospectively. Total amounts of morphine equivalents were calculated and converted into oxycodone 5 mg pills for standardization. P-values of <0.05 were considered significant. Results: Two hundred forty-four patients with a mean age of 50 years (±16.3) and a BMI of 29 (±6.1) were included. Sixty-six (27%) patients underwent a soft tissue procedure alone and 178 (73%) underwent a bony procedure. 225 (92.2%) patients received regional block. Patients reported that they consumed only 51.2% of prescribed pills after a bony procedure and 42.4% after a soft tissue procedure, respectively, which resulted in a total of 4,496.2 left over pills that derived from this study amongst only 244 patients enrolled. There were 11 refill requests (4.5%), two (0.8%) additional MD/ED visits, and 19 (7.8%) telephone calls related to pain. BMI, procedure type, and number of opioids prescribed were positively correlated with the consumption rate (P =.002, P<.001, P<0.001, respectively). Conclusion: BMI, surgery type (bony vs. soft tissue), and a higher number of pills dispensed were correlated with higher use in the postoperative period. After an educative discussion on postoperative pain, patients took 42.4% of the prescribed opioid after soft tissue procedures and 51.2% after bony procedures, resulting in a significant number of unused pills now available to the community. Future guidelines are necessary to improve our postoperative pain management, but this study suggests that current amounts of dispensed pills after orthopaedic F&A procedures are approximately twice as high as necessary

Normal Variation of the Lisfranc Joint: Tridimensional Analysis using Weight-Bearing Computed Tomography Imaging

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: Untreated Lisfranc injuries can lead to chronic pain, midfoot arthritis, and functional disability 1,2,5. Approximately 20% of Lisfranc injuries are misdiagnosed or completely missed on initial evaluation, which can be attributed to a lack of parameters of what is within normal limits for subjects without injury in the Lisfranc complex3,4. The purpose of this study is to identify anatomic variations of unidimensional, bidimensional, and tridimensional (1D, 2D, 3D) measurements of the Lisfranc complex of normal individuals using weight-bearing computed tomography (WBCT) imaging. Our hypothesis is that there is some variation among individuals with a difference between right and left of the same individual of less than 10%. Methods: A total of 191 subjects with bilateral WBCT scans of the foot were collected from three tertiary medical centers from 2019-2022. Exclusion criteria included: history of Lisfranc injury, first to fourth metatarsal base fractures, Charcot arthropathy, midfoot arthritis, cuneiform fractures, and forefoot surgery proximal to the metatarsal neck region. The following Lisfranc joint measurements were collected6 bilaterally: joint volume (3D), area of the joint on a consistent axial slice (2D), and distance between the second metatarsal and medial cuneiform (1D). Foot alignment was assessed using lateral talar-first metatarsal angle (Meary’s Angle). Patient demographics (age, sex, weight, height, BMI) were also collected. Descriptive statistics were calculated for quantitative variables. Percent difference was used to assess volume, area, and distance variation between sides.7 Correlation between demographic data and Lisfranc measurements was assessed using Pearson Correlation tests. A T-test was used for categorical variables. A p-value < 0.05 was considered statistically significant. Results: The cohort included 61% female and 39% male with an average age of 45.2±17.3 years. The mean volume, area, and distance measurements of the Lisfranc joint for both left and right sides are shown in Figure 1. Overall, the mean percent difference between left and right sides were 11.9%, 14.9% and 13.9% for volume, area and diastasis, respectively (Figure 1). No association was found between age, BMI, or weight and the volume, area or distance measurements. A correlation (r=0.48, p= < 0.001) was found between height and left Lisfranc joint volume, but no other measurements. Significant difference between sex in volume (p < 0.001) and area (p < 0.001) measurements were found. Foot alignment did not have a correlation with a variation of the Lisfranc complex measurements. Conclusion: This study provides an objective characterizing of the anatomic variations of the Lisfranc joint amongst healthy individuals. Differences in the measurements and the large standard deviation in absolute measurements of volume, area, and distance suggests that percent difference with the contralateral side may be a better metric to use to diagnose Lisfranc instability. Our results showed that the difference between bilateral sides in a patient is less than 15% for volume, area, and diastasis. The results of this study can set the foundation for future studies to determine the cut-off value for the diagnosis of Lisfranc instability using WBCT imaging

Determining the Causal Effect of Statins on Reducing the Incidence of Venous Thromboembolism after Ankle Fractures

Category: Ankle; Other Introduction/Purpose: It can be challenging to decide when to give preventative medication for venous thromboembolism (VTE). It is challenging to identify VTE in its early phases, and surgeons disagree on when prophylaxis should be given and when to suspect VTE. Additionally, patients who are not at a high risk of VTE are advised not to take prophylaxis due to the potential risk of bleeding adverse events and the evidence does not fully support providing prophylaxis in isolated foot and ankle procedures (BAE). The effectiveness of prevention, particularly in isolated foot and ankle fractures, is debatable, and research into how patients react to statins is necessary. By utilizing causal inference techniques, this research simulates a randomized control trial (RCT) from observational data. Methods: Out of a total of 1,175 patients, 238 had confirmed VTE 180 days after the incidence of ankle fracture (Case group, n=238). The inclusion criteria were 1- ankle fracture diagnosed by a physician and confirmed radiologically via X-ray or CT scan; 2- Age of 18 years or older; 3- Symptomatic VTE confirmed by a clinician and through radiologic (Duplex ultrasound, CT angiography, and/or angiography). To infer causal effects, we took the three following steps: first, the causal diagram must be created. Second, the set of variables necessary for causal inference must be identified. Third, the average treatment effect should be estimated for different treatment regimens. Results: Table 1 shows the incidence of VTE among patients who had VTE chemoprophylaxis. A non-significant 2.9% increase in VTE incidence was found, 95% CI [-1%, 7%]. The results state that, if a patient is already taking Statins, the incidence of VTE is reduced by 1%, 95% CI [-4.2%, 2.8%] as compared to patients who are not taking the drug which is not statistically significant. This indicates that there is no significant difference between administering VTE prophylaxis or not, in patients that are already consuming Statins. On the contrary, for patients in the sample that are not already taking Statins, the VTE incidence increases by 6%, 95% CI [1.6%, 10%] compared to no treatment administration which is significant since the confidence interval does not contain 0. Conclusion: Our findings provide more evidence that VTE prophylaxis may not, on average, be successful in lowering the incidence of VTE after ankle fracture, particularly in individuals who do not take Statins. To put it another way, doctors may decide not to give extra prophylaxis to avoid VTE in isolated ankle fractures if a patient is on Statins. Here, we established the causal inference methodology that can help us reproduce the results of an expensive RCT

A Novel Ultrasonographic Method to Detect Intra-Operative Syndesmotic Malreduction – the “Gap Penetrance” Sign

Category: Ankle; Other Introduction/Purpose: Anatomical reduction of the distal syndesmosis can be challenging. There is ongoing debate and variability in the methods used for evaluating the accuracy of reduction, including radiography, intra-operative CT, arthroscopy, and direct visualization. Tornetta et al. have described a method called ‘the articular surface method’ that evaluates the relationship between the articular cartilage of the distal anteromedial fibula and the anterolateral tibia as being significantly more accurate for detecting malreduction. However, it entails an additional surgical incision over the distal aspect of the ankle. The aim of this study was to find a non-invasive method using ultrasound to assess the accuracy of reduction in syndesmotic injuries. Methods: A cadaveric syndesmotic instability model was created by dissecting the PITFL, IOL, and AITFL through a small posterior incision. The fibula was fixed in incremental degrees of rotational malreduction to achieve a malreduction of 3, 5, and 7 mm. A blinded observer assessed the syndesmosis using a portable ultrasound device. The probe was placed in its short axis at the level of the ankle joint then moved proximally until both the anteromedial fibular and anterolateral tibial articular surfaces were visualized simultaneously in one view. In a reduced syndesmosis, the distal articular surfaces of the tibia and fibula overlap. This relationship is altered in a malreduced syndesmosis, which allows ultrasonographic waves to ‘penetrate’ through the malreduced articular surfaces and be readily detected. This sign was graded positive if an acoustic signal penetrated between the distal articular surfaces of the tibia and fibula, and negative if no acoustic signal was detected. Results: The gap penetrance sign was positive in all 3 instances of malreduced syndesmoses, and negative in an anatomically reduced syndesmosis. Figure 1 illustrates the outcomes in a reduced syndesmosis and malreduced syndesmosis, respectively. Conclusion: We introduced a novel sign that can be used as a surrogate of the ‘articular surface method’ to detect syndesmotic malreduction. It is accurate, can obviate the need for a separate surgical incision for direct visualization, permits rapid point-of- care evaluation in the operating room, and minimizes radiation exposur

3D Weightbearing CT for the Diagnosis of Lisfranc Instability: An Update

Category: Midfoot/Forefoot; Other Introduction/Purpose: Lisfranc instability is often a challenging injury to diagnose, with up to one-third being missed on initial evaluation. Lisfranc instability is assessed by widening of the space between the second metatarsal base and the medial cuneiform. This space is visualized on X-Ray; however, in subtle Lisfranc instability cases computed tomography (CT) imaging is often obtained. Given the 1D nature of diastasis measurement, X-ray should be an adequate means of evaluating this widening, yet clinical practice suggests weightbearing CT (WBCT) is more sensitive. This suggests the 3D location of the diastasis measurement is crucial. This study aimed to first compare weight-bearing X-ray and WBCT diastasis and area measurements of the Lisfranc complex, and second to compare WBCT diastasis measurements at various locations in the coronal plane. Methods: A total of 90 patients with both weight-bearing foot X-ray and bilateral foot WBCT were included: 37 patients had confirmed Lisfranc instability, and 53 patients had no history of midfoot injury. Lisfranc instability was confirmed intraoperatively or by clinical examination performed by the surgeon. For all 90 patients, the interosseous diastasis and area between the medial cortex of the second metatarsal and the lateral cortex of the medial cuneiform were measured on both weightbearing X-ray and axial slices of WBCT. For a subset of patients (12 in each cohort) the diastasis between second metatarsal and medial cuneiform was measured at 4 distinct axial locations using coronal slices of the WBCT (Figure 1). Results: A Wilcoxon test comparison of diastasis and area measurements on weightbearing X-ray and axial slices of WBCT revealed a significant difference in the weightbearing X-ray and WBCT measurements (p < 0.001) for both the control and Lisfranc cohorts. A comparison of weightbearing X-ray diastasis to dorsal, interosseous, and plantar diastasis measurements on coronal slices using Kruskal Willis analysis for the control cohort revealed a significant difference in all three measurements (Figure 1, p-values listed). Kruskal Willis analysis of the Lisfranc cohort demonstrated a significant difference between the X-ray diastasis and the plantar WBCT diastasis (p=0.01), but no difference from interosseous (p=0.08) or dorsal (p=0.33) diastases. A comparison of the axial WBCT diastasis measurements compared to the three coronal diastasis measurements revealed no difference in either cohort. Conclusion: Our results showed that for assessing the Lisfranc joint in subtle cases and healthy individuals, WBCT remains the most accurate imaging tool. However, in patients with confirmed Lisfranc instability, X-ray measurements are more reliable if the instability is at the dorsal and interosseous levels and not the plantar level. Hence, to assess the Lisfranc joint at different levels, WBCT has superiority over X-ray. Additionally, the axial diastasis of the Lisfranc joint on WBCT seems similar to coronal diastasis rendering both views reliable for measurements

The Accuracy of 3D Measurements in Weightbearing Computed Tomography to Diagnose Lisfranc Instability

Category: Midfoot/Forefoot; Other Introduction/Purpose: Up to one-third of Lisfranc injuries are missed on initial evaluation, resulting in significant morbidity. Prompt diagnosis of Lisfranc injuries is, therefore, critical in optimizing outcomes, and yet there remains a lack of consensus on diagnostic criteria to identify Lisfranc instability using anatomic measurements. Prior studies have underscored the utility of weight-bearing computed tomography (WBCT) in diagnosing Lisfranc instability, which allows for bilateral three-dimensional (3D) evaluation under physiologic load. The aim of this study was to quantify appropriate cutoff values using 3D anatomic measurements of Lisfranc instability under physiologic load and as compared to the uninjured extremity. Methods: A total of 234 adult patients with bilateral WBCT scans of the foot were included: 43 patients with Lisfranc instability & 191 patients without a history of midfoot injuries. Lisfranc instability was confirmed intraoperatively or by clinical evaluation by the surgeon. Patients with prior midfoot surgery, Charcot arthropathy, severe midfoot arthropathy, or significantly displaced fracture of the cuneiforms or 1st, 2nd, or 3rd metatarsal bases were excluded. Lisfranc joint measurements were conducted bilaterally, including C1-M2 diastasis, C1-M2 area and 3D WBCT volume. Patient demographics were collected. Descriptive statistics were calculated for quantitative variables. Percent difference as compared to the contralateral side was calculated for volume, area, and diastasis. Mann Whitney U tests were utilized to determine differences in measurements between patients in the Lisfranc cohort and patients in the uninjured cohort (p-value < 0.05). Diagnostic cutoffs for Lisfranc instability were determined with minimum distance to the corner analysis on ROC curves. Results: The distribution of patients with Lisfranc instability was 58% female with an average age of 38.5±17.6 years. Of the Lisfranc injuries, 36% were purely ligamentous, 18% demonstrated an avulsion injury, and 43% involved a metatarsal base fracture. In the Lisfranc cohort, the median percent difference between injured and uninjured feet was 28.2% (IQR: 20.9%) for volume, 36.3% (IQR: 31.1%) for C1-M2 area, and 40.0% (IQR: 23.3%) for C1-M2 diastasis. Mann-Whitney testing was significant for percent difference between left and right feet for Lisfranc patients versus patients with an uninjured midfoot (p < 0.001). The area under the curve and associated diagnostic cutoffs for Lisfranc instability, were 0.81 and 18% for volume, 0.84 and 20% for area, and 0.91 and 28% for diastasis (Figure 1). Conclusion: Diastasis (1D), area (2D), and volume (3D) measurements are effective measurements to diagnose Lisfranc instability on WBCT. With current diagnostic algorithms, however, 1D measurements afford superior diagnostic sensitivity as compared to 2D and 3D measurements when using WBCT, suggesting Lisfranc instability may be best appreciated in the axial plane. Additional studies are necessary to expand the sample population to assess for corroboration with the current results, especially for subtle Lisfranc instability

The Validity of Using ICD-9 Codes for Identifying Venous Thromboembolism Following Below Knee Surgery

Category: Other Introduction/Purpose: To determine the incidence of venous thromboembolism (VTE) after surgeries performed below the knee, previous studies have used the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes to identify a DVT (deep vein thrombosis) or PE (pulmonary embolism) event. The purpose of this study was (1) to determine the incidence of VTE in a large cohort of patients who had undergone surgery below the knee, and (2) to assess the validity of the ICD-9-CM procedure codes used. Methods: Current Procedural Terminology codes and ICD-9-CM codes were used to identify patients who had undergone below knee surgery and a reported VTE. The medical records of 21,904 patients were evaluated to assess the validity of the VTE ICD-9-CM code against the documentation of DVT or PE in radiology reports. Positive predictive value (PPV) and sensitivity of ICD-9-CM codes were calculated. Results: The incidence of VTE was 2.5% (552/21,904). Of those patients identified as having VTE, 344 (62.3%) had a DVT, 130 (23.6%) had a PE, and 78 (14.1%) were recorded as having both a DVT and PE. The PPV of ICD-9-CM coding were 55.7% (327/587) for DVT, 84.4% (108/128) for PE, 60.2% (59/98) for DVT/PE combined, and 60.8% (494/813) for VTE in total. The resulting sensitivity scores were 95.1% (327/344) for DVT, 83.1% (108/130) for PE, 75.6% (59/78) for DVT/PE combined, and 89.5% (494/552) for VTE in total. Conclusion: The overall rate of VTE after below knee surgery was 2.5%. This study found that ICD-9 code use had an 89.5% sensitivity rate for VTE. Using ICD-9 codes to search for a VTE demonstrated a low PPV, however, because only 60.8% could be verified by a radiological study. By comprehensively assessing the incidence of VTE after below knee surgery, we illustrated a potential source of inaccuracy in the use of retrospective ICD-9 based data capture methodologies