Postoperative Maintenance of Sagittal Plane Positioning of the First Metatarsophalangeal Joint After Arthrodesis with an Isolated Dorsal Plate Construct: A Retrospective Review of 43 Feet.

BACKGROUND: First metatarsophalangeal joint arthrodesis with isolated dorsal plating without a lag screw and without a compressive mechanism incorporated into the plate is not well studied. Although surface area for bony fusion is increased, there is concern for lower fusion rates and progressive loss of sagittal plane positioning. We present fusion rates and progressive sagittal plane deviation with isolated dorsal plate fixation. METHODS: A retrospective review was performed of 41 patients (43 feet) who underwent first metatarsophalangeal joint arthrodesis with isolated dorsal plate fixation. Patients were excluded if another form of fixation was used, if there was a compressive feature to the dorsal plate, or if a lag screw was used. Preoperative, immediate postoperative, and final postoperative radiographs were reviewed to assess radiographic alignment and fusion about the first metatarsophalangeal joint. Specific attention was placed on hallux dorsiflexion in relation to the first metatarsal. Statistical significance was set at P ≤ .05 a priori. RESULTS: Patients were followed for an average of 55.7 weeks. Overall union rate was 97.62%. The average time to union was 42.55 days. Reoperation rate was 4.65%, with one patient requiring revisional arthrodesis with a lag screw construct. Hallux abduction and first-second intermetatarsal angle correction reached significance (P < .00001). Hallux dorsiflexion increased by 1.05° between initial postoperative and final postoperative radiographs (P = .542). CONCLUSIONS: Although fusion rates and progressive loss of sagittal plane position have been concerns for first metatarsophalangeal joint arthrodesis with an isolated dorsal plate construct, these results suggest this to be a stable construct without loss of positioning over time.

Does the Subtalar or Tibiotalar Joint Need Fused in Primary Retrograde Tibiotalocalcaneal Nailing for Fragility Ankle Fractures?

BACKGROUND: As an alternative to traditional open reduction internal fixation of ankle fragility fractures, primary retrograde tibiotalocalcaneal (TTC) nailing has been investigated as a treatment option. These results suggest that this treatment is an acceptable alternative treatment option for these injuries. There are still questions about the need for formal joint preparation at the subtalar or tibiotalar joint when performing primary TTC nailing for fragility fractures. METHODS: In this study, we retrospectively evaluated 32 patients treated with primary retrograde TTC nail without subtalar or tibiotalar joint preparation for a mean of 2.4 years postoperatively. We specifically reviewed the charts for nail breakages at either joint, patients developing subtalar or tibiotalar joint pathology requiring additional treatment, including return to the operating room for formal joint preparation. RESULTS: Fracture union occurred in 100% of patients. There were 3 cases (10.0%) of hardware failure, and 2 of these cases were asymptomatic and did not require any treatment. One patient (3.3%) developed hardware failure with nail breakage at the subtalar joint. This patient developed progressive pain and symptoms requiring revision surgery with formal arthrodesis of the subtalar and tibiotalar joint. CONCLUSIONS: This study shows that retrograde hindfoot nailing without formal subtalar or tibiotalar joint preparation is an acceptable potential treatment option in ankle fragility fractures. Mid-term follow-up demonstrates favorable outcomes without the need for formal joint preparation in this high-risk population. Comparative studies with higher patient numbers and long-term follow-up are needed to confirm the results of this study.Levels of Evidence: Level IV.

Throwing Shoulder Adaptations Are Not Related to Shoulder Injury or Pain: A Preliminary Report.

BACKGROUND: Overhead throwing in baseball and softball athletes induces shoulder adaptations theorized to increase risk of shoulder musculoskeletal injury (MSI) and/or pain due to range of motion (ROM) deficits. HYPOTHESIS: Shoulder ROM adaptations are associated with a higher risk for developing shoulder MSI and pain. STUDY DESIGN: Prospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 60 National Collegiate Athletic Association Division I athletes cleared for full athletic participation and free from upper extremity MSI in the last 4 weeks (age, 19.0 ± 1.2 years; weight, 82.1 ± 13.7 kg; height, 178.6 ± 11.2 cm; softball, n = 23; baseball, n = 37). Passive glenohumeral internal rotation (IR), external rotation (ER), and horizontal adduction (HA) ROM were measured with the scapula stabilized and used to categorize participants with/without external rotation gain (ERG), external rotation insufficiency (ERI), glenohumeral internal rotation deficit (GIRD), pathological GIRD, and posterior shoulder tightness (PST) before the competitive season. Groups were then compared to assess the incidence of shoulder MSI prospectively and prevalence of shoulder pain at the initial evaluation. RESULTS: Baseball and softball athletes demonstrated significantly less IR ROM in the dominant shoulder (50.6° ± 9.4°) compared with the nondominant shoulder (59.1° ± 8.6°; P < 0.01) and significantly more ER ROM (dominant, 104.6° ± 12.1°; nondominant, 97.7° ± 12.0°; P < 0.01). Incidence of shoulder MSI was 15% but was not significantly related to any shoulder adaptations. No significant relationship was found between prevalence of pain and any shoulder adaptations in the 27% of athletes with pain. CONCLUSION: Increased ER and decreased IR ROM adaptations in intercollegiate overhead throwing athletes do not appear to be correlated to risk of shoulder MSI or pain. CLINICAL RELEVANCE: The findings of this level 3 prospective study provide clinicians working with overhead athletes information regarding shoulder MSI risk and pain. It is recommended that clinicians should not use ROM adaptations exclusively to determine increased risk of shoulder MSI.

Diabetic ketoacidosis diagnosis in a hospital setting.

CONTEXT: Diabetic ketoacidosis (DKA) is an endocrine emergency that can occur in people with diabetes. Its incidence is estimated to be 220,340 hospital admissions each year. Treatment algorithms include fluid resuscitation, intravenous (IV) insulin infusion, and scheduled electrolyte and glucose monitoring. The misdiagnosis of DKA in the setting of hyperglycemic emergencies results in overtreatment and unnecessary increases in healthcare utilization and costs. OBJECTIVES: The aims of this study were to determine how often DKA is overdiagnosed in the context of other acute hyperglycemic emergencies, to describe the baseline characteristics of patients, to determine the hospital treatments for DKA, and to identify the frequency of endocrinology or diabetology consultation in the hospital setting. METHODS: A retrospective chart review was conducted utilizing charts from three different hospitals within a hospital system. Charts were identified utilizing ICD-10 codes for admissions to the hospital for DKA. If the patient was over 18 and had one of the diagnostic codes of interest, the chart was reviewed for further details regarding the criteria for DKA diagnosis as well as admission and treatment details. RESULTS: A total of 520 hospital admissions were included for review. DKA was incorrectly diagnosed in 28.4 % of the hospital admissions reviewed, based on a review of the labs and DKA diagnostic criteria. Most patients were admitted to the intensive care unit (ICU) and treated with IV insulin infusion (n=288). Consultation of endocrinology or diabetology occurred in 40.2 % (n=209) of all hospital admissions, and 128 of those consults occurred in ICU admissions. The diagnosis of DKA was incorrect in 92 of the patients admitted to the medical surgical unit (MSU) and in 49 of patients admitted to the ICU. CONCLUSIONS: Almost one third of hospital admissions for hyperglycemic emergencies were misdiagnosed and managed as DKA. DKA diagnostic criteria are specific; however, other diagnoses like hyperosmolar hyperglycemic syndrome (HHS), hyperglycemia, and euglycemic DKA can make an accurate diagnosis more complicated. Education directed at improving the diagnostic accuracy of DKA among healthcare providers is needed to improve diagnostic accuracy, ensure the appropriate use of hospital resources, and potentially reduce costs to the healthcare system.

Force-plate derived predictors of lateral jump performance in NCAA Division-I men's basketball players.

A lateral jump assessment may provide unique benefits in sports such as basketball that require multidirectional performance optimization. This study aimed to examine selected force-plate derived metrics as predictors of lateral jump task distance in men's basketball players. Twenty-two NCAA Division-I men's basketball players (19.4 ± 1.3 years, 95.0 ± 12.5 kg, 196.5 ± 8.1 cm) each performed six single leg lateral jumps while standing on a force plate (1200 Hz, Kistler Instrument Corp). The lateral jump task involved the subject beginning by standing on the force plate and jumping sideways off one foot and then landing on the floor with the opposite foot. Three-dimensional ground reaction force curves were used to identify the eccentric and concentric phases of the jump and variables were computed each from the lateral (y), vertical (z), and resultant (r) force traces. Peak ground reaction force (pGRF), ground reaction force angle (θr), eccentric braking rate of force development (ECC-RFD), average concentric force (CON-AVG), total jump duration, eccentric phase duration, and eccentric to total time ratio were evaluated for predictive ability. Three regression models were able to significantly (p<0.05) predict jump distance: (1) pGRFy, pGRFz, and θr (p<0.001, R2 = 0.273), (2) Relative pGRFy, Relative pGRFz, and θr ((p<0.001, R2 = 0.214), and (3) Relative CON-AVGy and Relative pGRFr (p<0.001, R2 = 0.552). While several force plate-derived metrics were identified as significant predictors, a model with Relative CON-AVGy and Relative pGRFr explained a greater variability in performance (R2 = 0.55) compared to the other variables which were low, yet also significant. These results suggest that lateral ground reaction forces can be used to evaluate lateral jump performance with the use of three-dimensional force plates. The identified predictors can be used as a starting point for performance monitoring, as basketball training interventions can be directed at specific improvements in the identified metrics.

Increased length of stay following total joint arthroplasty based on insurance type.

BACKGROUND: Increased length of stay after total joint arthroplasty has been shown to be a risk factor for peri-operative complications. The purpose of this study was to determine if Medicaid insurance would be a risk factor for increased length of stay after total joint arthroplasty. METHODS: We retrospectively reviewed a single surgeon's practice of 428 total hip and total knee arthroplasties who had insurance status of Medicaid, Medicare, Private or none. After exclusion criteria there were 400 patients. Patients with insurance status of Medicaid, Medicare or Private were then compared based on length of stay ≤ 2 days and length of stay > 2 days and then further analyzed using demographic, operative data, and total length of stay. RESULTS: Medicaid patients had an increased length of stay compared to patients with Medicare or Private insurance [1.98 days versus 1.73 days, p = .037, 95% confidence intervals (1.78-2.18) and (1.61-1.85), respectively]. The greatest predictor of a less than two-night stay post-operatively was private insurance status (p = 0.001). Medicaid patients had a higher incidence of prescribed narcotic use pre-operatively (p = 0.013). Although not significant, a trend was noted in the Medicaid population with higher incidence of smoking (p = 0.094) and illicit drug abuse (p = 0.099) pre-operatively in this sample subset. CONCLUSIONS: Patients with Medicaid insurance undergoing total joint arthroplasty have increased length of stay compared to patients with Medicare or Private insurance and have higher incidence of pre-operative narcotic use.

Isometric Knee Strength is Greater in Individuals Who Score Higher on Psychological Readiness to Return to Sport After Primary Anterior Cruciate Ligament Reconstruction.

Background: Anterior cruciate ligament (ACL) injury is extremely common among athletes. Rate of second ACL injury due to surgical graft rupture or contralateral limb ACL injury is approximately 15-32%. Psychological readiness to return to sport (RTS) may be an important predictor of successful RTS outcomes. Psychological readiness can be quantified using the ACL Return to Sport after Injury (ACL-RSI) questionnaire, with higher scores demonstrating greater psychological readiness. Purpose: The purpose of this study was to investigate differences in functional performance and psychological readiness to return to sport among athletes who have undergone primary ACL reconstruction (ACLR). Study Design: Descriptive cohort study. Methods: Eighteen athletes who had undergone primary ACLR were tested at time of RTS clearance. The cohort was divided into two groups, high score (HS) and low score (LS), based on median ACL-RSI score, and performance on static and dynamic postural stability testing, lower extremity isokinetic and isometric strength testing, and single leg hop testing was compared between the groups using an independent samples t-test. Results: The median ACL-RSI score was 74.17. The average ACL-RSI score was 83.1±6.2 for the HS group and 61.8±8.0 for the LS group. High scorers on the ACL-RSI performed significantly better on isometric knee flexion as measured via handheld dynamometry (22.61% ±6.01 vs. 12.12% ±4.88, p=0.001) than the low score group. Conclusion: The findings suggest that increased knee flexion strength may be important for psychological readiness to RTS after primary ACLR. Further research is indicated to explore this relationship, however, a continued emphasis on improving hamstring strength may be appropriate during rehabilitation following ACLR to positively impact psychological readiness for RTS. Level of Evidence: III.

The Resident-Run Clinic in Podiatric Medical Foot and Ankle Surgery Residency Training: A Study of Resident-Perceived Benefit.

BACKGROUND: Resident-run clinics provide autonomy and skill development for resident physicians. Many residency programs have such a clinic. No study has been performed investigating the effectiveness of these clinics in podiatric medical residency training. The purpose of this study was to gauge the resident physician-perceived benefit of such a clinic. METHODS: A survey examining aspects of a resident-run clinic and resident clinical performance was distributed to all Doctor of Podiatric Medicine residency programs recognized by the Council on Podiatric Medical Education. To be included, a program must have had a contact e-mail listed in the Central Application Service for Podiatric Residencies residency contact directory; 208 residency programs met the criteria. Statistical analysis was performed using independent-samples t tests or Mann-Whitney U tests and χ2 tests. Significance was set a priori at P < .05. RESULTS: Of 97 residents included, 58 (59.79%) had a resident-run clinic. Of those, 89.66% of residents stated they liked having such a clinic, and 53.85% of those without a resident-run clinic stated they would like to have one. No statistically significant differences were noted between groups in how many patients each resident felt they could manage per hour or regarding their level of confidence in the following clinical scenarios: billing, coding, writing a note, placing orders, conversing with a patient, working with staff, diagnosing and treating basic pathology, and diagnosing and treating unique pathology. CONCLUSIONS: Resident-run clinics provide autonomy and skill development for podiatric medical residents. This preliminary study found there was no difference in resident-perceived benefit of such a clinic. Further research is needed to understand the utility of a resident-run clinic in podiatric medical residency training.

Effect of Concussion on Reaction Time and Neurocognitive Factors: Implications for Subsequent Lower Extremity Injury.

Background: Recent evidence has demonstrated that athletes are at greater risk for a lower extremity injury following a return-to-sport (RTS) after sport-related concussion (SRC). The reason for this is not completely clear, but it has been hypothesized that persistent deficits in neurocognitive factors may be a contributing factor. Hypothesis/Purpose: This study assessed simple reaction time, processing speed, attention, and concentration in a group of athletes, post-concussion upon clearance for RTS for potential deficits that may result in slower reaction time, processing speed, attention, and concentration. The researchers hypothesized that the concussion group would demonstrate worse scores on both assessments compared to a sex-, age-, and sport-matched cohort. Study Design: Case-controlled study. Methods: Twelve participants who had suffered a SRC and eight healthy individuals who were matched to the concussed group by age, sex, and sport were evaluated. Those with a concussion had been cleared for RTS by a licensed healthcare provider. Each participant underwent neurocognitive tests that included a simple reaction time test (SRT) and the King-Devick Test (K-D). Independent t-tests were performed to compare the groups with significance set a priori at p<0.05. Results: There was a significant difference (p =0.024) between groups for SRT with the concussed group demonstrating a better SRT than the control group. There were no significant differences (p =0.939) between the groups for the K-D. Conclusion: With no significant differences between groups in the K-D assessment and, surprisingly, the concussed group having a better SRT compared to the healthy group, our hypothesis was not supported. Clinical Relevance: These specific measures, compounded with extensive post-concussion time lapse until RTS clearance, may have limited capacity in revealing potential persistent deficits in relevant neurocognitive characteristics. Level of Evidence: Level of Evidence 3.

Females have Lower Knee Strength and Vertical Ground Reaction Forces During Landing than Males Following Anterior Cruciate Ligament Reconstruction at the Time of Return to Sport.

Purpose: There is a high rate of second anterior cruciate ligament (ACL) injury (ipsilateral graft or contralateral ACL) upon return-to-sport (RTS) following ACL reconstruction (ACLR). While a significant amount of epidemiological data exists demonstrating sex differences as risk factors for primary ACL injury, less is known about sex differences as potential risk factors for second ACL injury. The purpose of this study is to determine if there are sex-specific differences in potential risk factors for second ACL injury at the time of clearance for RTS. Methods: Ten male and eight female athletes (age: 20.8 years ±6.3, height: 173.2 cm ±10.1, mass: 76.6 kg ±18.3) participated in the study following ACLR at time of RTS (mean 10.2 months). Performance in lower extremity isokinetic and isometric strength testing, static and dynamic postural stability testing, and a single leg stop-jump task was compared between the sexes. Results: Normalized for body weight, males had significantly greater isokinetic knee flexion (141±14.1 Nm/kg vs. 78±27.4 Nm/kg, p=0.001) and extension strength (216±45.5 Nm/kg vs. 159±53.9 Nm/kg, p=0.013) as well as isometric flexion (21.1±6.87% body weight vs. 12.5±5.57% body weight, p=0.013) and extension (41.1±7.34% body weight vs. 27.3±11.0% body weight, p=0.016) strength compared to females. In the single-leg stop jump task, males had a greater maximum vertical ground reaction force during landing (332±85.5% vs. 259±27.4% body weight, p=0.027) compared to females. Conclusions: Based on these results, there are significant differences between sexes following ACLR at the time of RTS. Lower knee flexion and extension strength may be a potential risk factor for second ACL injury among females. Alternatively, the increased maximum vertical force observed in males may be a potential risk factor of second ACL injury in males. Although these results should be interpreted with some caution, they support that rehabilitation programs in the post-ACLR population should be individualized based on the sex of the individual. Level of Evidence: Level 3.

Clinical Measures of Adolescent Softball Players With and Without Upper-Extremity Pain: A Preliminary Study.

CONTEXT: Upper-extremity (UE) pain is a concern among softball adolescent athletes. However, research on preseason screening of demographic characteristics and clinical measures among those with and without UE pain among adolescent softball athletes is underreported. This study sought to present functional outcomes and clinical measures of shoulder and hip complex flexibility, range of motion (ROM), and strength in adolescent softball athletes with and without UE pain. DESIGN: Cross-sectional study. METHODS: Sixty-seven athletes were assessed at the start of the spring season. The Kerlan-Jobe Orthopedic Clinic Shoulder and Elbow Questionnaire was administered to determine UE function. UE measurements included shoulder ROM, flexibility, and strength; lower-extremity measurements included hip ROM and strength. These variables were reported for players with and without UE pain as mean and SD. Independent samples t tests were performed to analyze differences between the groups. RESULTS: Thirteen (19.4%) athletes reported UE pain during preseason screening. Mean Kerlan-Jobe Orthopedic Clinic Shoulder and Elbow Questionnaire score among athletes with UE pain was 58.0 (17.6) compared with 97.1 (6.9) for athletes reporting no UE pain (P < .001). Athletes with UE pain presented with significantly less dominant side external rotation ROM (UE pain: 106.5 [10.4], no UE pain: 114.6 [11.3]) and total ROM (UE pain: 163.7 [14.5], no UE Pain: 174.8 [14.3]). CONCLUSION: These findings inform clinicians on function and preseason clinical measures in adolescent softball athletes who present with or without UE pain. Athletes with UE pain demonstrated lower outcome scores indicating likely impact on overall UE function. These athletes also appeared to demonstrate UE ROM differences compared with athletes without UE pain. Further research is needed to investigate larger sample sizes and positional differences at baseline and throughout the season to determine if clinical measures used in the current study are risk factors for pain and injury.

The association between lower extremity strength ratios and the history of injury in collegiate athletes.

CONTEXT: Strength ratios are important because imbalances in opposing muscle groups can cause articular instability and subsequently increase the risk of musculoskeletal injury (MSKI). Therefore, the purpose of this study was to evaluate the association between lower extremity (LE) musculoskeletal isometric strength ratios and the history of LE MSKI. PARTICIPANTS: One hundred eighty-two NCAA Division 1 soccer, football, volleyball, and basketball athletes. INTERVENTIONS: All isometric strength assessments were measured bilaterally using a handheld dynamometer. Strength assessments included: ankle inversion/eversion, ankle dorsiflexion/plantarflexion, knee flexion/extension, hip abduction/adduction, and hip external/internal rotation. LE MSKI history was collected through self-report; a report of the LE MSKI sustained in the one year prior to testing were collected. RESULTS: The hip external/internal rotation ratio was statistically significant for side to side differences in the non-injured (NINJ) group (p = 0.001). The dominant leg of the NINJ group had a mean external/internal rotation ratio of 1.109 ± 0.221, and the non-dominant leg had a mean ratio of 1.177 ± 0.208. CONCLUSIONS: There were no statistically significant differences between the injured (INJ) and NINJ groups. This could indicate that injury history does not play a role in current strength ratios and could suggest that the athletes in the INJ group are performing successful rehabilitation for their injuries.

Evaluation of heparin infusion rates in patients with intravenous drug misuse.

To evaluate the hypothesis that patients with a history of intravenous drug misuse (IVDM) initiated on weight-based heparin infusions require higher than expected infusion rates to achieve therapeutic activated partial thromboplastin time (aPTT). This study is a multicenter, retrospective chart review of patients with a history of IVDM who were admitted to an acute care site between 10/1/2015 and 9/30/2020 and treated with continuous heparin infusions. Patients were identified using ICD9 and ICD10 codes and included if they had a documented history of IVDM within the past six months. Variables of particular interest included: median heparin infusion rates to maintain therapeutic aPTT, average time to reach therapeutic aPTT, and International Society of Thrombosis and Haemostasis Criteria for moderate to severe bleeding. Of the 41 patients who met the inclusion and exclusion criteria, 39 achieved therapeutic aPTT while on a weight-based heparin infusion. All heparin infusions were initiated at a rate of 18 units/kg/hr then titrated per institutional heparin infusion protocols. The mean time to therapeutic aPTT was 38.48 h ± 26.4 h with a mean infusion rate of 27.64 ± 7.14 units/kg/hr. To maintain therapeutic anticoagulation, infusion rates 150% higher than the initial rate were required. Of the 39 patients who achieved therapeutic aPTT, 85% (33) met criteria for heparin resistance, defined as greater than 35,000 units of heparin daily. No statistical significance could be derived from this retrospective chart review as therapeutic heparin rates were evaluated in comparison to initial infusion rate, rather than a control group. The findings in this study demonstrate a possible clinical association of the reduced antithrombin activity previously described in opiate misusers. To efficiently achieve therapeutic anticoagulation, it may be appropriate to consider use of heparin antiXa monitoring in place of aPTT or utilization of increased initial heparin infusion rates.

Altered lower extremity biomechanics following anterior cruciate ligament reconstruction during single-leg and double-leg stop-jump tasks: A bilateral total support moment analysis.

BACKGROUND: Injury to the anterior cruciate ligament (ACL) can lead to long-lasting biomechanical alterations that put individuals at risk of a second ACL injury. Examining the total support moment may reveal between- and within-limb compensatory strategies. METHODS: Twenty-six participants who were cleared to return to sport following ACL reconstruction were recruited. Each participant completed the single-leg and double-leg stop jump tasks. These tasks were analyzed using force plates and a 3D motion analysis system. The total support moment was calculated by summing the internal moments of the hip, knee and ankle at peak vertical ground reaction force. FINDINGS: Internal knee extensor moment was lower in the involved limb compared to the uninvolved for both tasks (17.6%, P = 0.022; 18.4%, P = 0.008). No significant between-limb differences were found for the total support moment. The involved limb exhibited an 18.2% decrease in knee joint contribution (P = 0.01) and a 21.6% increase in ankle joint contribution (P = 0.016) to the total support moment compared to the uninvolved limb in the single-leg stop jump task. INTERPRETATION: Compensation for the involved knee is likely due to altered biomechanics that redistributes load to the uninvolved knee or to adjacent joints of the same limb. A partial shift in joint contribution from the knee to the ankle during the single-leg stop jump task demonstrates a tendency to decrease load to the knee. Further studies are needed to investigate how these adaptations impact the prevalence of subsequent injury and poor joint health.

Examining Sex Differences in Visual Reliance During Postural Control in Intercollegiate Athletes.

BACKGROUND: Risk factors for different sports injuries vary between sexes. Deficits in postural stability have been associated with several lower extremity injuries. The purpose of this study was to examine the differences in static postural stability between male and female intercollegiate athletes with and without visual information. # HypothesisThere will be no difference in visual reliance between sexes during static postural stability. STUDY DESIGN: Cross-sectional Study. METHODS: Static postural stability was assessed during a single session for football, soccer, basketball, and volleyball intercollegiate athletes (males, n=135, females, n=51) under eyes open (EO) and eyes closed (EC) conditions via performance of single limb stance on a force plate. Ground reaction force component data in all directions were quantified as a unitless composite score (COMP) where lower values indicated better postural stability. The absolute change and percentage change between EO and EC conditions were calculated for each sex. Two-sample Kolmogorov-Smirnov tests were used to compare differences between sexes. RESULTS: Males had greater EO COMP (males=7.77±3.40; females=6.48±4.61; p=0.038; Cohen's d=0.343) and EC COMP (males=19.43±8.91; females 14.66±6.65; p=0.001; Cohen's d=0.571) than females. A significant difference in absolute change from EO to EC was observed between sexes (males=-11.65±7.05; females=-8.18±5.61; p=0.01, Cohen's d=-0.520) indicating that males had a greater change between conditions for the worse. There was no significant difference in percent change from EO to EC between sexes (males=159.2±90.7; females=156.7±109.2; p=0.39; Cohen's d=0.026). CONCLUSIONS: The observed differences between males and females in EO COMP, EC COMP, and absolute difference in COMP indicate that there is some factor that causes a difference in static postural stability between sexes. No difference in percent change between groups indicates that the difference in static postural stability between sexes may not be due to visual reliance. Female athletes may inherently have better postural stability than males, but both sexes were able to compensate for the loss of visual input. LEVEL OF EVIDENCE: 3.

The July Effect in Podiatric Medicine and Surgery Residency.

The period when medical students begin residency in teaching hospitals throughout the United States heralds a period known in the medical community as the "July Effect." Though several sentinel studies associated this timeframe with an increase in medical errors, residencies since demystified this phenomenon within their respective specialty. This study aims to evaluate the presence of the July Effect in a podiatric medicine and surgery residency program. A retrospective chart review was conducted, comparing patient demographics and surgical outcomes including length of stay, operative time and readmission rate between the first (July, August, September) and fourth (April, May June) quarters of the academic year from 2014-2019. A total of 206 patients met the inclusion criteria, where 99 received care in the first, resident-naïve, quarter and 107 received care in the fourth, resident-experienced, quarter. No difference in patient demographics including sex, body mass index, or comorbidity index was appreciated between both quarters (p<0.05). Those patients who underwent soft tissue and bone debridements, digital, forefoot, midfoot and rearfoot amputations experienced no statistically significant difference in length of stay, operative time, or readmission rate between both quarters (p<0.05). The results of this study did not support the presence of the July Effect in our foot and ankle surgery residency. Future studies can further explore this phenomenon by examining patients admitted following traumatic injury or elective procedures. Moreover, this study shows the curriculum employed at our program provides sufficient support, guidance, and resources to limit errors attributed to the July Effect.

The Relationship Between Hip Strength and Postural Stability in Collegiate Athletes Who Participate in Lower Extremity Dominant Sports.

BACKGROUND: Lower extremity (LE) injuries are common across many sports. Both core strength (including hip strength) deficits and poor postural stability have been linked to lower extremity (LE) injury. The relationship between these two characteristics is unknown. PURPOSE: To explore the relationships between hip strength, static postural stability, and dynamic postural stability. STUDY DESIGN: Descriptive Cross-Sectional Study. METHODS: 162 Division I student-athletes (111 males and 51 females) participated in this study. Isometric hip strength was measured using a hand-held dynamometer and both single-leg static (eyes open EO and eyes closed EC) and dynamic postural stability were assessed with a force plate. Pairwise correlations were calculated to examine the relationship between the hip strength variables and the postural stability scores for all subjects and separately for males and females. RESULTS: There were no significant correlations between hip strength and dynamic postural stability for any of the pairwise correlations. Significant, albeit minimal, correlations between EO and EC static postural stability and each of the hip strength variables for all subjects and male subjects (correlation coefficients ranged from -0.19 to -0.34). However, there were only two significant correlations between hip strength and EC static postural stability (hip internal/external rotation) and one for hip strength and EO postural stability (hip internal rotation) found for female subjects (correlation coefficients ranged from -0.28 to -0.31). CONCLUSION: There was no relationship between isometric hip strength and dynamic postural stability; whereas, there were some relationships between the strength measures and static postural stability. These significant, but minimal correlations were observed in more of the comparisons within the male cohort potentially demonstrating a sex difference. LEVEL OF EVIDENCE: 3b.

Machine Learning to Predict Lower Extremity Musculoskeletal Injury Risk in Student Athletes.

Injury rates in student athletes are high and often unpredictable. Injury risk factors are not agreed upon and often not validated. Here, we present a random-forest machine learning methodology for identifying the most significant injury risk factors and develop a model of lower extremity musculoskeletal injury risk in student athletes with physical performance metrics spanning joint strength measured with force transducers, postural stability measured using a force plate, and flexibility, measured with a goniometer, combined with previous injury metrics and athlete demographics. We tested our model in a population of 122 student athletes with performance metrics for the lower extremity musculoskeletal system and achieved an injury risk accuracy of 79% and identified significant injury risk factors, that could be used to increase accuracy of injury risk assessments, implement timely interventions, and decrease the number of career-ending or chronic injuries among student athletes.

Examination of the Feasibility of a 2-Dimensional Portable Assessment of Knee Joint Stability: A Pilot Study.

Rupture of the anterior cruciate ligament (ACL) remains extremely common, with over 250,000 injuries annually. Currently, clinical tests have poor utility to accurately screen for ACL injury risk in athletes. In this study, the position of a knee marker was tracked in 2-dimensional planes to predict biomechanical variables associated with ACL injury risk. Three-dimensional kinematics and ground reaction forces were collected during bilateral, single-leg stop-jump tasks for 44 healthy male military personnel. Knee marker position data were extracted to construct 2-dimensional 95% prediction ellipses in each anatomical plane. Knee marker variables included: ellipse areas, major/minor axes lengths, orientation of ellipse axes, absolute ranges of knee position, and medial knee collapse. These variables were then used as predictor variables in stepwise multiple linear regression analyses for 7 biomechanical variables associated with ACL injury risk. Knee flexion excursion, normalized peak vertical ground reaction forces, and knee flexion angle at initial contact were the response variables that generated the highest adjusted R2 values: .71, .37, and .31, respectively. The results of this study provide initial support for the hypothesis that tracking a single marker during 2-dimensional analysis can accurately reflect the information gathered from 3-dimensional motion analysis during a task assessing knee joint stability.

Postural Stability Under Dual-Task Conditions: Development of a Post-Concussion Assessment for Lower-Extremity Injury Risk.

CONTEXT: Concussions are consequence of sports participation. Recent reports indicate there is an increased risk of lower-extremity musculoskeletal injury when returning to sport after concussion suggesting that achieving "normal" balance may not fully indicate the athlete is ready for competition. The increased risk of injury may indicate the need to refine a screening tool for clearance. OBJECTIVE: Assess the between-session reliability and the effects of adding a cognitive task to static and dynamic postural stability testing in a healthy population. SETTING: Clinical laboratory. PARTICIPANTS: Twelve healthy subjects (6 women; age 22.3 [2.9] y, height 174.4 [7.5] cm, weight 70.1 [12.7] kg) participated in this study. DESIGN: Subjects underwent static and dynamic postural stability testing with and without the addition of a cognitive task (Stroop test). Test battery was repeated 10 days later. Dynamic postural stability testing consisted of a forward jump over a hurdle with a 1-legged landing. A stability index was calculated. Static postural stability was also assessed with and without the cognitive task during single-leg balance. Variability of each ground reaction force component was averaged. MAIN OUTCOME MEASURES: Interclass correlation coefficients (ICC2,1) were computed to determine the reliability. Standard error of measure, mean standard error, mean detectable change, and 95% confidence interval were all calculated. RESULTS: Mean differences between sessions were low, with the majority of variables having moderate to excellent reliability (static .583-.877, dynamic .581-.939). The addition of the dual task did not have any significant effect on reliability of the task; however, generally, the ICC values improved (eyes open .583-.770, dual task .741-.808). CONCLUSIONS: The addition of a cognitive load to postural stability assessments had moderate to excellent reliability in a healthy population. These results provide initial evidence on the feasibility of dual-task postural stability testing when examining risk of lower-extremity musculoskeletal injury following return to sport in a concussed population.