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Objective: Micronutrient status, specifically vitamin D and iron, represent modifiable factors for optimizing military readiness. The primary purpose of this investigation was to determine associations between micronutrient deficiency (i.e., iron status and 25-hydroxy-vitamin D [25(OH)D]) and operationally relevant outcomes (i.e., skeletal health, musculoskeletal injury) at baseline and post-10 weeks of arduous military training. Methods: A total of 227 (177 men, 50 women) Marine Officer Candidates School (OCS) candidates who completed OCS training with complete data sets were included in this analysis. Vitamin D and iron status indicators were collected at two timepoints, pre (baseline) and post OCS. Musculoskeletal outcomes at the mid- and proximal tibial diaphysis were assessed via peripheral quantitative computed tomography. Results: Micronutrient status declined following OCS training in men and women and was associated with musculoskeletal outcomes including greater bone strength (strength strain index) at the mid-diaphysis site in those with optimal status (M = 38.26 mm3, SE = 15.59) versus those without (M = −8.03 mm3, SE = 17.27). In women (p =.037), endosteal circumference was greater in the deficient group (M = 53.26 mm, SE = 1.19) compared with the optimal group (M = 49.47 mm, SE = 1.31) at the proximal diaphysis. In men, greater baseline hepcidin concentrations were associated with an increased likelihood of suffering musculoskeletal injury during training. Conclusions: Vitamin D and iron status declined over the course of training, suggesting impaired micronutrient status. Differences in musculoskeletal outcomes by micronutrient group suggests optimal vitamin D and ferritin concentrations may exert beneficial effects on bone fatigability and fracture reduction during military training. [ABSTRACT FROM AUTHOR]

We examined the effectiveness of occupational therapy intervention combined with standard rehabilitation in patients undergoing high tibial osteotomy (HTO). Overall, 115 patients with HTO for knee osteoarthritis were examined. An intervention group (n = 50), who received occupational therapy and standard rehabilitation, was compared to a control group (n = 65), who underwent standard rehabilitation only (n = 65). Compared with the control group, the intervention group had significantly lower Hospital Anxiety and Depression Scale depression and anxiety scores (both p < 0.05), with between-group differences showing large- and medium-effect sizes, respectively (d = 1.06 and 0.61). Results suggest occupational therapy with rehabilitation during hospitalization improves depression and anxiety rates in patients post-HTO. [ABSTRACT FROM AUTHOR]

Background: No clear agreement exists on the degree of bone formation required to remove a metal plate without correction loss after medial opening-wedge high tibial osteotomy (MOWHTO). We aimed to investigate the mechanical stability of the proximal tibia with different bone formations after plate removal in MOWHTO using finite element models and determine the extent of bone formation when the plate can be removed without correction loss. Methods: The MOWHTO models with 5, 10, and 15 mm opening gaps were generated. The mechanical stability of proximal tibial models with different extents of bone formation (from the lateral cortex of the osteotomy wedge to 20% (zone 1), 40% (zone 2), 50% (zone 2.5), 60% (zone 3), 70% (zone 3.5), 80% (zone 4), and 100% bone formation medially) after plate removal was analyzed using finite element analysis. Bone stress and strain and micromotion were evaluated to investigate fracture risk and bone stability, respectively, in various types of tibial models. Results: Peak von Mises stress was lower than yield strength when bone formation reached zone 3.5 (70%) or more in 5- and 10-mm osteotomy gap models, and zone 4 (80%) or more in a 15-mm gap model. Maximal principal strains were lower than 6,130 microstrain when bone formation reaches zone 3.5 (70%) or more in models with osteotomy gaps of 5, 10, and 15 mm. Conclusions: This indicates that plate removal without correction loss after MOWHTO may be possible when bone formation reaches zone 3.5 (> 70%) or more during 5- and 10-mm osteotomy gap corrections, and zone 4 (> 80%) or more during 15-mm gap correction. The present study results suggest that it would be safer to perform plate removal after obtaining sufficient bone formation rather than performing it near the osteotomy gap center (50%) to avoid correction loss considering both coronal and sagittal plane aspects. [ABSTRACT FROM AUTHOR]

Background: An open fracture of the tibia is one of the most common and dangerous type of open fractures. In the management of these injuries, the primary focus is on reducing the infection rate, as this is crucial for achieving the best clinical outcomes. This study aims to explore how provisional external fixation duration influences the rates of infection and union in open tibial shaft fractures. Methods: A retrospective study with a total of 55 patients who received temporary external fixation. Groups A (less than 12 days), B (12–24), C (25–36), and D (more than 36) were the four groups into which they were split according to the conversion time. Results: 12.8%, 18.2%, 50%, and 100% of the infections were found in Groups A, B, C, and D, respectively. Significant (P < 0.05) differences were found throughout the four groups. The conversion time from external to definitive fixation was found to have a relationship with the occurrence of an infection (P = 0.004). A higher prevalence of infection was observed over time. However, no association was observed between infection and antibiotic duration or initial debridement time (P = 0.689 and P = 0.963, respectively). Conclusions: Results of this study demonstrate that the likelihood of infection increases when the change from external fixation to definitive internal fixation is delayed. Therefore, it is important to convert to definitive internal fixation immediately when the local and general conditions are favorable for doing so. [ABSTRACT FROM AUTHOR]

Objective: This study aims to assess the significance of monitoring temperature change trends at various wound sites in the healing process of diabetic foot ulcers after microcirculation reconstruction surgery. Methods: A retrospective analysis was conducted on individuals with diabetic foot ulcers who had been admitted to the Department of Orthopedics at the Second Hospital of Shanxi Medical University between July 2020 and February 2022. Temperature changes were regularly monitored at the center of the wound and the distal tibia of the ipsilateral lower leg to assess microcirculatory blood perfusion. Wound, ischemia, and foot infection (WIFi) grading was performed at admission and the final follow-up was to determine the value of temperature monitoring at various sites. Additionally, the formation of collateral microarterial vessels was monitored to determine their consistency with the observed trends in temperature differences. Follow-up assessments included the recurrence of ulcers, development of ulcers at different locations, re-amputation of the toe or limb, and diabetes-related mortality. Results: A total of 29 patients were included in the follow-up, with an average age of 57.14 ± 14.75 years and a follow-up period of 9.79 ± 4.13 months. Following microcirculation reconstruction surgery, as the microvascular network formed, the temperature difference between the center of the wound and the distal tibia on the same side gradually decreased, with no statistical difference observed at 4 weeks postoperatively. At both admission and the final follow-up, there was a significant reduction in the wound (W) and ischemia (I) grades within the WIFi classification. The temperature at the wound center showed progressive improvement as collateral microarterial vessels developed. During the follow-up period, there were 2 cases of ulcer recurrence, 1 case of an ulcer appearing at a different location, no cases of re-amputation of the toe or limb, and 2 diabetes-related fatalities. Conclusion: Skin temperature monitoring offers a direct and reliable indication of microcirculatory blood perfusion. Its simplicity and cost-effectiveness make it a valuable tool for widespread use in evaluating wound healing following microcirculation reconstruction surgery. [ABSTRACT FROM AUTHOR]

Two long-distance runners developed medial tibial stress syndrome (MTSS; male age = 26.3 years, female age = 47.5 years) after baseline assessment of plantar-flexor muscle structure and function and spatiotemporal running variables. B-mode ultrasound and lean leg girth characterized plantar-flexor muscle structure. Handheld dynamometry and a single-leg heel raise–to-failure protocol characterized plantar-flexor muscle function. Finally, spatiotemporal running variables were determined during a treadmill protocol. The 2 runners who developed MTSS demonstrated less plantar-flexor strength and endurance capacity than published comparative control data and marked variability in muscle structure. Reduced plantar-flexor strength and endurance capacity were thought to contribute to an impaired ability to resist tibial-bending moments during midstance due to earlier muscle fatigue. Earlier muscle fatigue could, in turn, contribute to increased tibial-bending moments and MTSS development. Therefore, assessing plantar-flexor muscle strength and endurance might help to identify athletes at risk of developing MTSS. [ABSTRACT FROM AUTHOR]

Ensuring proper femoral component alignment post-Total Knee Arthroplasty (TKA) is crucial for normal patellofemoral (PF) kinematics. However, the customary 3° external rotation relative to the Posterior Condylar Axis (PC Axis) may not universally apply, and the expected final femoral component rotation remains unclear in functionally aligned knees. This study examines the relation between the Transepicondylar Axis (TEA) and PC axis, known as Posterior Condylar Angle (PCA) in Indian patients along with factors influencing PCA, and the feasibility of reproducing patient-specific PCA using image-guided Cuvis joint robot. Forty patients (52 Knees) with primary osteoarthritis and varus deformity were prospectively evaluated. Native PCA was determined using CT-based J planner. Pre-operative patellar shape, PF tilt, PF shift, final femoral component rotation (representing post-operative PCA), final patellar tracking, and post-operative functional and radiological assessment at 3 months were recorded. Study participants averaged 64.3 years of age, with a female-to-male ratio of 23 to 17. Varus deformities varied, with IA2 being most prevalent, and sagittal plane deformities included fixed flexion (34.6 %) and hyperextension (44.2 %). The average PCA was 1.9° (range: 0°–7.3°), with most knees (41 out of 52) below 3°. The majority had Wiberg type 1 patellae, with pre-operative patellar tilt averaging 5.63°, reducing post-operatively to 4.43°. Most patients (37 out of 40) achieved excellent Knee Society functional scores at the 3-month mark. Complications included one case of delayed wound healing and one femoral array pin breakage. Notably, our study revealed a significant deviation in PCA from the commonly reported 3° in Western literature, underscoring the need for region-specific considerations in TKA planning. PCA of our population is statistically different from customary 3° followed with jig system. Image guided Robotics helps to identify patients specific PCA and reproducing the same was more commonly possible in patients with reducible Varus deformity. [ABSTRACT FROM AUTHOR]

Inertial measurement units (IMUs) attached to the distal tibia are a validated method of measuring lower-extremity impact accelerations, called tibial accelerations (TAs), in runners. However, no studies have investigated the effects of small errors in IMU placement, which would be expected in real-world, autonomous use of IMUs. The purpose of this study was to evaluate the effect of a small proximal shift in IMU location on mean TAs and relationships between TAs and ground reaction force loading rates. IMUs were strapped to 18 injury-free runners at a specified standard location (∼1 cm proximal to medial malleolus) and 2 cm proximal to the standard location. TAs and ground reaction forces were measured while participants ran at self-selected and 10% slower/faster speeds. Mean TA was lower at the standard versus proximal IMU location in the faster running condition (P =.026), but similar in the slower (P =.643) and self-selected conditions (P =.654). Mean TAs measured at the standard IMU explained more variation in ground reaction force loading rates (r2 =.79−.90; P <.001) compared with those measured at the proximal IMU (r2 =.65−.72; P <.001). These results suggest that careful attention should be given to IMU placement when measuring TAs during running. [ABSTRACT FROM AUTHOR]

Field-based tibial acceleration measurements are increasingly common but sampling frequencies vary between accelerometers. The purpose of this study was to determine the minimum sampling frequency needed for reliable and accurate measurement of peak axial and resultant tibial acceleration during running in the field. Tibial acceleration was measured at 7161 Hz in 19 healthy runners on concrete and grass. Acceleration data were down sampled to approximate previously used sampling frequencies. Peak axial and resultant tibial acceleration were calculated for each sampling frequency. The within-session reliability and accuracy of peak axial and resultant tibial accelerations were evaluated using intraclass correlation coefficients, mean differences, and 95% limits of agreements. Intraclass correlation coefficients greater than.9 indicated excellent within-session reliability for both peak axial and resultant tibial acceleration measured while running on concrete and grass. Peak axial and resultant tibial accelerations were 0.5 to 1.4 g lower and minimal detectable differences were up to 0.6 g higher at 102 Hz compared with higher sampling frequencies. We recommend a minimum sampling frequency of 199 Hz for accurate and reliable measurements of peak axial and resultant tibial acceleration in the field. [ABSTRACT FROM AUTHOR]

Objectives: To explore the immediate and retention effect of real-time tibial acceleration feedback on running biomechanics during gait retraining. Methods: Five electronic databases were searched to identify relevant studies published before May 2022. The included studies were evaluated for methodological quality and bias risk, and data were extracted. A meta-analysis was conducted on the primary outcomes, including peak tibial acceleration (PTA) and vertical ground reaction force. Subgroup analysis was performed by gender, feedback criterion, mode, dosage, fading, retention period, and running environment to evaluate the source of heterogeneity. Qualitative analysis was performed to describe other variables. Results: Fourteen studies (174 participants) were eligible. Meta-analysis showed that real-time tibial acceleration feedback reduced PTA (P < .01, P < .01), vertical impact peak (P = .004, P < .01), vertical average loading rate (P < .01, P < .01), and vertical instantaneous loading rate (P < .01, P < .01) after feedback and during retention period (5 min-12 mo). Subgroup analysis showed that the immediate effect of vertical impact peak was more noticeable with mixed gender (P = .005) and fading feedback (P = .005) conditions, and the retention effect of PTA was more noticeable with high feedback dosage (P < .01) and fading feedback (P < .01) conditions. Conclusions: Real-time tibial acceleration feedback can reduce PTA and vertical ground reaction force during gait retraining, and for periods of 5 minutes to 12 months when the feedback is removed. [ABSTRACT FROM AUTHOR]

Background: Primary implant stability is important for successful outcomes after uncemented total ankle replacement (TAR). However, the influence of patient-specific bone density on TAR performance is poorly understood, especially for implants that rely on press-fit for stable primary fixation. Our goal was to evaluate how bone density influences implant-bone interfacial micromotions in 3 press-fit tibial component designs by sampling from a TAR preoperative planning database using finite element analysis (FEA). Methods: FEA was conducted in 4 TAR patients with relatively low-density (n = 2, lowest 10% of a sample including 58 patients) and average-density (n = 2, midrange of sample) bone as assessed from deidentified patient CT scans. Three tibial implant designs were evaluated: a bone-sparing resurfacing implant, a cortex-sparing anterior approach monoblock stemmed implant, and a distal-reaming modular stemmed implant. Implants were inserted into tibia geometries obtained from the CT scans. Press-fit implantation was modeled first, followed by loadings from the stance phase of gait, and the associated micromotions were computed from the FEA output. Results: In general, patients with average-density bone had FEA predicted lower micromotions than patients with low-density bone. FEA suggests that implant fixation features had less influence on micromotions in patients with average-density bone, with peak micromotions ranging from 2 to 23 µm (3.1 ± 1.3 µm average micromotion). For patients with low-density bone, interfacial regions are predicted to experience micromotions exceeding the bony ingrowth threshold of 50 µm only for the resurfacing implant. Conclusion: We investigated the influence of bone density on implant-bone micromotions with varying primary fixation features using FEA. The model predicts that micromotions are less in average-density bone, regardless of implant fixation features. However, both stemmed devices showed lower micromotions in less-dense bone, albeit with the corresponding clinical trade-off of requiring more tibial bone removal. Clinical Relevance: The results presented here implicate the complementary role that local bone density plays in the primary fixation stability of uncemented TAR. [ABSTRACT FROM AUTHOR]

This study was aimed to compare the knee kinematic parameters between dominant and non-dominant legs of adolescent female athletes during change of direction (CoD) in fatigued and unpredictable settings. Knee kinematic parameters on 49 athletes (mean± SD; age = 14.69 ± 0.14 years; mass = 49.05 ± 1.22 kg; height = 1.61 ± 0.08 m) during CoD before and after performing the Bruce protocol and also in predictable and unpredictable setting situations were collected. Kinematic data were recorded at a sampling rate of 200 Hz. The results showed that the dominant leg had significantly 18.7% more flexion (p = 0.001, η = 0.95), 7.1% less valgus (p = 0.001, η = 0.95) and 0.32% lower tibia rotation (p = 0.003, η = 0.16) compared to the non-dominant leg in predictable and pre-fatigue (p < 0.05) conditions. With unpredictable and post-fatigue conditions the dominant limb again demonstrated 17.4% (p = 0.001, η = 0.67), greater knee flexion, 6.8% (0.003,η = 0.97) lower knee valgus and 1.4% (p = 0.001, η = 0.71) less tibiarotation. In conclusion, there may be an increased risk of injury withthe non-dominant leg due to changes in kinematic parameters caused by fatigue and unpredictable CoD manoeuvres. [ABSTRACT FROM AUTHOR]

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Background: High tibial osteotomy (HTO) aims to realign the varus knee to alleviate stress in the medial compartment. However, detailed information on the impact of HTO on stress distribution across the tibiofemoral joint surface still needs to be completely elucidated. Purpose/Hypothesis: The present study aimed to analyze the subchondral bone density distribution to validate the alignment threshold causing paradoxical changes. We hypothesized that there would be a paradoxical stress change in the medial compartment beyond a specific threshold for lower limb realignment after HTO. Study Design: Case series; Level of evidence, 4. Methods: A retrospective clinical study of 32 knees from 30 patients who underwent medial opening-wedge HTO between 2015 and 2019 was conducted at Hokkaido University Hospital. The subchondral bone density across the tibiofemoral joint was analyzed using computed tomography–osteoabsorptiometry before and after HTO. The high-density area (HDA) within the medial and lateral compartments and their subregions, which were quartered in the coronal plane, was specifically examined. Results: The hip-knee-ankle angle, medial proximal tibial angle (MPTA), joint line obliquity (JLO), and joint line convergence angle significantly changed after HTO (P <.01). The HDA of the medial compartment to the total HDA ratio decreased from 83% to 77%. Paradoxically, the HDA in the most central subregion of the medial compartment increased from 24% to 30%. There were significant differences between MPTA and JLO in patients with and without paradoxical changes in the HDA. MPTA and JLO cutoff values causing paradoxical changes in the HDA were 94° and 4°, respectively. Conclusion: There was a paradoxical stress increase in the M4 region at the medial compartment associated with the MPTA and JLO beyond specific thresholds. Therefore, surgical planning should be cautiously performed to prevent overcorrection, which can lead to adverse stress distribution changes. [ABSTRACT FROM AUTHOR]

Posterior pilon variant ankle fractures (PPVF) are a unique subtype of posterior malleolar fractures which have been a source of controversy and confusion in recent years. There has not been a thorough literature review previously written on the topic. Database searches of PubMed and Embase were conducted from inception until June 2023. The key words included "pilon variant," "posterior pilon variant," and "posterior pilon" fractures. Outcomes were evaluated by union time, rates of delayed union, nonunion, malunion, and complication. A total of 15 articles relevant to surgical repair of pilon variant fractures were included in the literature review. The unique mechanism of injury has been reported to involve both rotational and axial forces, leading to involvement of the posterior and medial aspects of the distal tibia. Pilon variant fractures can be suspected by several characteristics on radiographs and have a high confirmation rate via CT images. Multiple systems have been proposed to classify this fracture pattern, but there is no consensus on the ideal classification system. Surgically, direct fixation has shown better short-term clinical outcomes versus indirect fixation or no fixation. PPVF have a distinct fracture pattern involving the posterior and medial columns of the distal tibial plafond, and results from a mechanism intermediate to rotational and axial forces. These fractures are more severe than tri-malleolar fractures due to increased rates of articular impaction and incongruity. Future classification systems should focus on joint surface area and the tibial pilon column involved to avoid confusion with less severe posterior malleolar fractures. [ABSTRACT FROM AUTHOR]

Lower extremity injuries are prevalent in military trainees, especially in female and older trainees. Modifiable factors that lead to higher injury risk in these subgroups are not clear. The purpose of this study was to identify whether external loading variables during military‐relevant tasks differ by age and sex in U.S. Army trainees. Data was collected on 915 trainees in the first week of Basic Combat Training. Participants performed running and ruck marching (walking with 18.1 kg pack) on a treadmill, as well as double‐/single‐leg drop landings. Variables included: vertical force loading rates, vertical stiffness, first peak vertical forces, peak vertical and resultant tibial accelerations. Comparisons were made between sexes and age groups (young, ≤19 years; middle, 20–24 years; older, ≥25 years). Significant main effects of sex were found, with females showing higher vertical loading rates during ruck marching, and peak tibial accelerations during running and ruck marching (p ≤ 0.03). Males showed higher vertical stiffness during running and peak vertical tibial accelerations during drop landings (p < 0.01). A main effect of age was found for vertical loading rates during running (p = 0.03), however no significant pairwise differences were found between age groups. These findings suggest that higher external loading may contribute to higher overall injury rates in female trainees. Further, higher stiffness during running may contribute to specific injuries, such as Achilles Tendinopathy, that are more prevalent in males. The lack of differences between age groups suggests that other factors contribute more to higher injury rates in older trainees. Highlights: Female trainees showed higher lower extremity loading during running and ruck marching that may predispose them to higher rates of musculoskeletal injury during initial‐entry training.Male trainees showed higher stiffness during running, which may relate to an increased risk of specific musculoskeletal injuries that are more prevalent in males, such as Achilles tendinopathy.Overall, older trainees did not show different lower extremity loading patterns compared to younger, suggesting that these factors are not related to the increased risk for musculoskeletal injury in older trainees. [ABSTRACT FROM AUTHOR]

Summary: Non-pharmacological therapies, such as whole-food interventions, are gaining interest as potential approaches to prevent and/or treat low bone mineral density (BMD) in postmenopausal women. Previously, prune consumption preserved two-dimensional BMD at the total hip. Here we demonstrate that prune consumption preserved three-dimensional BMD and estimated strength at the tibia. Purpose: Dietary consumption of prunes has favorable impacts on areal bone mineral density (aBMD); however, more research is necessary to understand the influence on volumetric BMD (vBMD), bone geometry, and estimated bone strength. Methods: This investigation was a single center, parallel arm 12-month randomized controlled trial (RCT; NCT02822378) to evaluate the effects of 50 g and 100 g of prunes vs. a Control group on vBMD, bone geometry, and estimated strength of the radius and tibia via peripheral quantitative computed tomography (pQCT) in postmenopausal women. Women (age 62.1 ± 5.0yrs) were randomized into Control (n = 78), 50 g Prune (n = 79), or 100 g Prune (n = 78) groups. General linear mixed effects (LME) modeling was used to assess changes over time and percent change from baseline was compared between groups. Results: The most notable effects were observed at the 14% diaphyseal tibia in the Pooled (50 g + 100 g) Prune group, in which group × time interactions were observed for cortical vBMD (p = 0.012) and estimated bone strength (SSI; p = 0.024); all of which decreased in the Control vs. no change in the Pooled Prune group from baseline to 12 months/post. Conclusion: Prune consumption for 12 months preserved cortical bone structure and estimated bone strength at the weight-bearing tibia in postmenopausal women. [ABSTRACT FROM AUTHOR]

Coronal Plane Alignment of the Knee (CPAK), is an informative way to classify native knee alignment types, but does not consider posterior tibial slope, an important variable in knee kinematics. We hypothesized that tibial slope would have a significant effect on knee kinematics and warrant consideration in addition to the CPAK system. We examined 335 adult patients with osteoarthritis receiving total knee arthroplasty. We measured the lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and posterior tibial slope angle (PTS). Knees were categorized into CPAK classes and subdivided into types 'A' (PTS 8°) or 'B' (PTS >8°). We recorded pre-and-post operative knee flexion, and extension/flexion gaps in all subjects. CPAK classes VII-IX were not seen. Classes I and II comprised a plurality of all knees. One-third of all knees were type B. CPAK classes III, IV, and VI had greater type B proportions, but this was not statistically significant. Type B knees had greater flexion both pre-op (p <.001) and post-op (p =.043); type A knees had greater flexion improvement pre-to-post operatively (p =.045). Type A knees had greater medial and lateral flexion-extension gap change pre-operatively (p =.021) and (p =.027), respectively. Type B knees had greater medial-lateral gap imbalance preoperatively in both flexion and extension. Our results suggest that there are important pre and post-operative differences in medial and lateral femorotibial gap balance between type A and B knees that require consideration for intra-operative balancing. Differences in knee flexion further solidify that PTS is an important variable that affects kinematics before and after TKA. We propose the addition of PTS types A and B to the existing CPAK classes. This is an easy and logical way to create a comprehensive classification system in both coronal and sagittal planes that captures further differences in knee kinematics. [ABSTRACT FROM AUTHOR]

Several open-source platforms for markerless motion capture offer the ability to track 2-dimensional (2D) kinematics using simple digital video cameras. We sought to establish the performance of one of these platforms, DeepLabCut. Eighty-four runners who had sagittal plane videos recorded of their left lower leg were included in the study. Data from 50 participants were used to train a deep neural network for 2D pose estimation of the foot and tibia segments. The trained model was used to process novel videos from 34 participants for continuous 2D coordinate data. Overall network accuracy was assessed using the train/test errors. Foot and tibia angles were calculated for 7 strides using manual digitization and markerless methods. Agreement was assessed with mean absolute differences and intraclass correlation coefficients. Bland–Altman plots and paired t tests were used to assess systematic bias. The train/test errors for the trained network were 2.87/7.79 pixels, respectively (0.5/1.2 cm). Compared to manual digitization, the markerless method was found to systematically overestimate foot angles and underestimate tibial angles (P <.01, d = 0.06–0.26). However, excellent agreement was found between the segment calculation methods, with mean differences ≤1° and intraclass correlation coefficients ≥.90. Overall, these results demonstrate that open-source, markerless methods are a promising new tool for analyzing human motion. [ABSTRACT FROM AUTHOR]

This study evaluated learning and recall effects following a feedback-based retraining program. A 6-month follow-up of a quasi-randomized controlled trial was performed with and without recall. Twenty runners were assigned to experimental or control groups and completed a 3-week running program. A body-worn system collected axial tibial acceleration and provided real-time feedback on peak tibial acceleration for six running sessions in an athletic training facility. The experimental group received music-based biofeedback in a faded feedback scheme. The controls received tempo-synchronized music as a placebo for blinding purposes. The peak tibial acceleration and vertical loading rate of the ground reaction force were determined in a lab at baseline and six months following the intervention to assess retention and recall. The impacts of the experimental group substantially decreased at follow-up following a simple verbal recall (i.e., run as at the end of the program): peak tibial acceleration:-32%, p = 0.018; vertical loading rate:-34%, p = 0.006. No statistically significant changes were found regarding the retention of the impact variables. The impact magnitudes did not change over time in the control group. The biofeedback-based intervention did not induce clear learning at follow-up, however, a substantial impact reduction was recallable through simple cueing in the absence of biofeedback. [ABSTRACT FROM AUTHOR]

Background: There is a higher rate of failure of isolated MPFL reconstruction in skeletally immature patients with patellar instability compared to skeletally mature patients. Genu valgum is a known risk factor for patellar instability. There is potential for concomitant surgical correction of genu valgum to achieve better clinical outcomes and to decrease failure rates of MPFL reconstruction. Purpose: To evaluate outcomes of combined medial patellofemoral ligament (MPFL) reconstruction and implant-mediated guided growth (IMGG) in skeletally immature patients with patellar instability and genu valgum. Study Design: Case series; Level of evidence, 4. Methods: In a multicenter study, all skeletally immature patients with recurrent patellar instability and genu valgum who underwent MPFL reconstruction using hamstring graft and IMGG using a transphyseal screw or tension band plate for the distal femur and/or proximal tibia were included. The knee valgus angle and mechanical axis were measured on full-length radiographs and anatomic risk factors were measured on MRI. Patients were followed until correction of their lower limb alignment and implant removal or until skeletal maturity. Clinical outcomes, including complications, were analyzed. Results: A total of 31 patients (37 knees) were included in the study. The mean age and skeletal age of the cohort were 12.4 and 12.9 years, respectively. Simultaneous MPFL reconstruction and IMGG were performed in 26 of 37 knees; 11 underwent staged procedures. Twenty knees had transphyseal screws and 17 knees had tension band plates for IMGG. The knee valgus corrected from a mean of 12.4° to 5.1° in 12.1 months. Implants were removed from 22 of 37 knees once genu valgum was corrected. There was no significant difference (P =.65) in the correction rate between plates (0.7 deg/month) and screws (0.6 deg/month). Ten complications occurred in 4 patients (7 knees) and included 5 patellar redislocations, 2 rebound valgus, 1 varus overcorrection, 1 knee arthrofibrosis, and 1 implant loosening. For children <10 years of age, 3 of 6 (50%) knees had patellar redislocations and 5 of 6 knees had a complication. This was statistically significant (P =.003) compared with patients >10 years of age. Similarly, for patients with bilateral knee involvement, 5 of 12 (42%) knees had patellar redislocations and a total of 8 complications occurred in this subset. This was statistically significant (P <.001) compared with patients with unilateral involvement. Conclusion: IMGG with plates or screws in the setting of combined MPFL reconstruction improves genu valgum. Children <10 years of age and those with bilateral instability with genu valgum remain difficult subsets to treat with higher complication rates. [ABSTRACT FROM AUTHOR]

Background: The treatment of distal tibia fractures (DTF) has historically been a difficult challenge for orthopedic surgeons because of the particular characteristics of this anatomical region. Intra medullary nailing (IMN) remains the best treatment option. However, achieving and maintaining perfect reduction and stable fixation with IMN can be technically challenging due to the large medullary cavity within a short distal fragment. The aim of our study is to determine the risk factors for malunion in DTF treated with IMN. Methods: It is a retrospective study including DTF treated surgically by IMN in the Orthopedics and Trauma Department at a tertiary hospital over a period of 7 years. The quality of reduction was evaluated by radiological assessment of the antero-posterior (AP) and lateral views of the tibia and ankle at the last follow-up. Results: Our series included 90 patients with an average age of 44.8 years. Sex-ratio was 2.6. Tobacco use was reported in 35.6% of the patients. Diabetes was present in 11.1% of the patients, and 12.2% of them had open fractures. According to the OTA/AO classification, the majority of injuries were classified as type A1 (76.7%). Fibula fractures were present in 86.7% of cases. The mean follow-up was 48 months. Malunion occurred in 13 cases. Based on the univariate analysis, smoking and dynamic fixation were significantly associated with malunion. In the multiple logistic regression analysis, dynamic fixation was found to be a significant factor that increased the risk of malunion by 7.5 times. Conclusion: Neither patient demographics nor fracture characteristics were risk factors for malunion. Nevertheless, it should be noted that dynamic nailing must be avoided as it is associated with a higher risk of malunion. Furthermore, one to two medial to lateral distal locking screws provide sufficient stability without the need for additional fibular fixation. Trial registration: Not applicable. [ABSTRACT FROM AUTHOR]

Background: It is unclear whether the use of polyetheretherketone (PEEK) interference screws for anterior cruciate ligament (ACL) reconstruction leads to postoperative tunnel enlargement. Femoral tunnel enlargement was further compared with adjustable-length loop cortical fixation. Methods: Eighteen patients with ACL reconstruction using hamstring grafts were retrospectively divided into two groups. Eleven patients were treated with the ACL reconstruction technique using a PEEK interference screw for femoral graft fixation. Seven patients received adjustable-length loop cortical buttons for femoral fixation. Tibial ACL graft fixation was performed using PEEK interference screws. Tunnel volume changes were assessed using computed tomography (CT) scans performed after surgery (100%) and after 1 year. The maximal tunnel diameter was measured. Results: The group with femoral screw fixation showed a mean tunnel volume change of 108.15 ± 13.7% on the tibial side and 124.07 ± 25.38% on the femoral side. The group with femoral button fixation showed a tunnel volume change of 111.12 ± 12.72% on the tibial side and 130.96 ± 21.71% on the femoral side. The differences in femoral tunnel volume changes were not significant (P = 0.562). Femoral tunnels with PEEK screw fixation showed significantly larger diameter after 12 months in comparison with button fixation (13.02 ± 1.43 mm vs. 10.46 ± 1.29 mm, P < 0.001). Conclusions: PEEK interference screws were associated with significant tibial and femoral tunnel enlargement. Femoral tunnel enlargement was comparable between PEEK interference screws and button fixation. Final femoral tunnel diameter was significantly larger with PEEK screw fixation in comparison to button fixation. [ABSTRACT FROM AUTHOR]

Tibial stress injuries are problematic among runners. The loading magnitude is the most important mechanical contributor to bone damage accumulation, but loading quantity is also important, and faster runners require fewer loading cycles to complete a given distance than slower runners. This study estimated tibial loading and damage accumulation throughout a demanding 10‐km run in recreational (RR) and competitive runners (CR). Male runners reporting a 10‐km season‐best run slower than 47:30 min (RR) or faster than 37:30 min (CR) completed a 10‐km treadmill running protocol at 105% of their season's best time. Tibial loading was estimated from bending moments at the distal 1/3rd of the tibia by ensuring static equilibrium at each 1% of stance. Peak loading was obtained, and cumulative damage per kilometer was estimated using a tissue‐dependent weighting factor. Peak tibial loading and damage accumulation per kilometer significantly decreased throughout the run, by 5% and 4%, respectively. Peak loading was significantly higher (31%) in CR than RR, and there was an indication (p = 0.058 and large effect size) of a greater rate of damage accumulation in CR than RR. Tibial loading per step and the rate of accumulation per kilometer decreased throughout a demanding 10‐km run suggesting that changes in running mechanics as a result of prolonged running may not be a primary mechanism for stress injury development. Competitive runners experience greater peak tibial loading and possibly greater cumulative tibial damage when they complete 10 km faster than recreational runners. Highlights: Peak tibial loading per step and the rate of damage accumulation decreased throughout a demanding 10‐km run in both recreational and competitive runners.Running‐induced changes in gait mechanics may not be a predominant mechanism for the development of tibial stress injuries.Completing a 10‐km run at a faster speed requires fewer loading cycles, but this does not result in reduced tibial damage accumulation due to the greater loading magnitude. [ABSTRACT FROM AUTHOR]

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Introduction: Tibial stress injuries are a burdensome injury among military recruits. Military activities include running and the carriage of additional weight, and this may be related to the high risk of bone stress injuries. The aim of this study was to quantify tibial loading when running at two different speeds, with and without additional weight, and to quantify their combined influence. Methods: Fourteen male distance runners who ran at least 40 km per week ran barefoot on a force‐instrumented treadmill in four conditions representing preferred running speed (mean (SD) 3.1 (0.3) m/s) and 20% increased running speed (3.8 (0.4) m/s), with and without 20% of body weight carried in a weight vest. Kinematics and kinetics were synchronously collected. Bending moments were estimated about the medial‐lateral axis of the tibial centroid located 1/3rd of the length from distal to proximal. Static equilibrium was ensured at each 1% of stance. Peak bending moments were obtained in addition to cumulative‐weighted loading, where weighted loading accounted for the relative importance of the magnitude of the bending moment and the quantity of loading using a bone‐dependent weighting factor. Results: There were no interaction effects for running speed and weight carriage on peak or cumulative tibial loading. Running at a 20% faster speed increased peak and cumulative loading per kilometer by 8.0% (p < 0.001) and 4.8% (p < 0.001), respectively. Carriage of an additional 20% of body weight increased peak and cumulative loading per kilometer by 6.6% (p < 0.001) and 8.5% (p < 0.001), respectively. Interpretation: Increasing the physical demand of running by increasing speed or weight carriage increased peak tibial loading and cumulative tibial loading per kilometer, and this may increase the risk of tibial stress injury. Running speed and weight carriage independently influenced tibial loading. [ABSTRACT FROM AUTHOR]

Purpose: Peak tibial acceleration (PTA) is defined as the peak acceleration occurring shortly after initial contact, often used as an indirect measure of tibial load. As the tibia is a rotating segment around the ankle, angular velocity and angular acceleration should be included in PTA. This study aimed to quantify three-dimensional tibial acceleration components over two different sensor locations and three running speeds, to get a better understanding of the influence of centripetal and tangential accelerations on PTA typically measured in running. Furthermore, it explores tibial impulse as an alternative surrogatemeasure for tibial load. Methods: Fifteen participants ran 90 s on a treadmill at 2.8, 3.3, and 3.9m·s--1,with inertialmeasurement units (IMUs) located distally and proximally on the tibia. Results: Without the inclusion of rotational accelerations and gravity, no significant difference was found between axial PTA between both IMU locations, whereas in the tangential sagittal plane axis, there was a significant difference. Inclusion of rotational accelerations and gravity resulted in similar PTA estimates at the ankle for both IMU locations and caused a significant difference between PTA based on the distal IMU and PTA at the ankle. The impulse showed more consistent results between the proximal and distal IMU locations compared with axial PTA. Conclusions: Rotational acceleration of the tibia during stance differently impacted PTA measured proximally and distally at the tibia, indicating that rotational acceleration and gravity should be included in PTA estimates. Furthermore, peak acceleration values (such as PTA) are not always reliable when using IMUs because of inconsistent PTA proximally compared with distally on an individual level. Instead, impulse seems to be a more consistent surrogate measure for the tibial load. [ABSTRACT FROM AUTHOR]

Background: Increased posterior tibial slope (PTS) and decreased patellar height (PH) after medial opening wedge high tibial osteotomy (MOWHTO) have been repeatedly reported in the literature. However, this has been disputed in more recent biomechanical studies. Hypothesis: No change in PTS or PH would result after MOWHTO with the freehand technique, regardless of the degree of the coronal plane correction. Study Design: Case series. Methods: A total of 62 patients who underwent MOWHTO between 2018 and 2020 were included. Surgery was performed using a dedicated step-by-step protocol to reduce the risk of unintentional slope changes. All patients were evaluated preoperatively and at a 2-year follow-up with the Knee injury and Osteoarthritis Outcome Score and the University of California, Los Angeles physical activity scale. Pre- and postoperative radiographic lower limb alignment parameters—including hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle, proximal posterior tibial angle (PPTA), joint line convergence angle, and joint line obliquity—were measured on full-length lower limb radiographs. PH measurements assessed on lateral and anteroposterior knee radiographs included the Caton-Deschamps, Insall-Salvati, and Schröter indices. Results: A significant change was observed in the coronal plane alignment, with an increase in the MPTA from 84.38° to 90.39° (P <.001) and a consequent increase in the HKA from 172.19° to 180.15° (P <.001). No significant changes were observed in the PTS, as evidenced by a postoperative PPTA of 80.6° versus a preoperative value of 80.4° (P =.2). No significant changes were detected in the mean PH on all 3 indices used—pre- versus postoperative Caton-Deschamps, Insall-Salvati, and Schröter indices measured 0.95 versus 0.93 (P =.2), 1.03 versus 1.03 (P =.5), and 1.56 versus 1.54 (P =.3), respectively. Conclusion: In this study, MOWHTO did not result in significant changes in the PTS or PH when accurate preoperative planning and precise intraoperative freehand technique were adopted.. [ABSTRACT FROM AUTHOR]

Context: Performance on single-leg hopping (SLH) assessments is commonly included within return-to-sport criteria for rehabilitating athletes. Triaxial accelerometers have been used to quantify impact loading in a variety of movements, including hopping; however, they have never been attached to the tibia during SLH, and their method of fixation has not been investigated. Objective: The purpose of this study was to quantify triaxial accelerations and evaluate the influence of the fixation method of a lightweight inertial measurement unit (Blue Trident) mounted to the tibia during SLH performance. Design: Single cohort, repeated-measures experimental design. Participants: Sixteen healthy participants (10 females and 6 males; 20 [0.9] y; 1.67 [0.08] m; 66.0 [8.5] kg) met the inclusion criteria, volunteered, and completed this study. Interventions: Participants performed 2 sets of 3 SLH trials with an inertial measurement unit (1500 Hz) fixated to the tibia, each set with 1 of 2 attachment methods (double-sided tape [DST] with athletic tape and silicon strap [SS] with Velcro adhesion). Main Outcome Measures: Hop distance, peak tibial acceleration (PTA), time to PTA, and the acceleration slope were assessed during each hop landing. Results: Repeated-measures analysis of variance determined no significant effect of the attachment method on hop metrics (P =.252). Across 3 trials, both fixation methods (DST and SS) had excellent reliability values (intraclass correlation coefficient:.868–.941) for PTA and acceleration slope but not for time to PTA (intraclass correlation coefficient:.397–.768). The PTA for DST (27.22 [7.94] g) and SS (26.21 [10.48] g) was comparable and had a moderate, positive relationship (DST: r =.72, P <.01; SS: r =.77, P <.01) to SLH distance. Conclusions: Tibial inertial measurement units with triaxial accelerometers can reliably assess PTA during performance of the SLH, and SS is a viable alternative tibial attachment to DST. [ABSTRACT FROM AUTHOR]

The coupling between the residual limb and the lower-limb prosthesis is not rigid. As a result, external loading produces movement between the prosthesis and residual limb that can lead to undesirable soft-tissue shear stresses. As these stresses are difficult to measure, limb loading is commonly used as a surrogate. However, the relationship between limb loading and the displacements responsible for those stresses remains unknown. To better understand the limb motion within the socket, an inverse kinematic analysis was performed to estimate the motion between the socket and tibia for 10 individuals with a transtibial amputation performing walking and turning activities at 3 different speeds. The authors estimated the rotational stiffness of the limb-socket body to quantify the limb properties when coupled with the socket and highlight how this approach could help inform prosthetic prescriptions. Results showed that peak transverse displacement had a significant, linear relationship with peak transverse loading. Stiffness of the limb-socket body varied significantly between individuals, activities (walking and turning), and speeds. These results suggest that transverse limb loading can serve as a surrogate for residual-limb shear stress and that the setup of a prosthesis could be individually tailored using standard motion capture and inverse kinematic analyses. [ABSTRACT FROM AUTHOR]

Runners experience repeated impact forces during training, and the culmination of these forces can contribute to overuse injuries. The purpose of this study was to compare peak vertical tibial acceleration (TA) in trained distance runners on 3 surface types (grass, asphalt, and concrete) and 3 grades (incline, decline, and level). During visit 1, subjects completed a 1-mile time trial to determine their pace for all running trials: 80% (5%) of the average time trial velocity. During visit 2, subjects were outfitted with a skin-mounted accelerometer and performed 18 separate running trials during which peak TA was assessed during the stance phase. Each subject ran 2 trials for each condition with 2 minutes of rest between trials. Peak TA was different between decline (8.04 [0.12] g) and incline running (7.31 [0.35] g; P =.020). On the level grade, peak TA was greater during grass (8.22 [1.22] g) compared with concrete (7.47 [1.65] g; P =.017). On the incline grade, grass (7.68 [1.44] g) resulted in higher peak TA than asphalt (6.99 [1.69] g; P =.030). These results suggest that under certain grade conditions grass may result in higher TA compared with either concrete or asphalt. [ABSTRACT FROM AUTHOR]

Medial tibial stress syndrome (MTSS) is a common running-related injury. Alterations in movement patterns and movement coordination patterns have been linked to the development of overuse injuries. The aim of this study was to compare transverse plane tibial and frontal plane rearfoot motion and the coordination of these movements between runners with MTSS and healthy controls. A total of 10 recreational runners with MTSS and 10 healthy controls ran at 11 km/h on a treadmill. A 3-camera motion analysis system operating at 200 Hz was used to calculate tibia and rearfoot motion. Stance phase motion patterns were compared between groups using multivariate analysis, specifically, Hotelling T2 test with statistical parametric mapping. A modified vector coding technique was used to classify the coordination of transverse plane tibial and frontal plane rearfoot motion. The frequency of each coordination pattern displayed by each group was compared using independent samples t tests. Individuals with MTSS displayed significantly (P =.037, d = 1.00) more antiphase coordination (tibial internal rotation with rearfoot inversion) despite no significant (P >.05) differences in stance phase kinematics. The increased antiphase movement may increase the torsional stress placed upon the medial aspect of the tibia, contributing to the development of MTSS. [ABSTRACT FROM AUTHOR]

A musculoskeletal model of the right lower limb was developed to estimate 3D tibial contact forces in high knee flexion postures. This model determined the effect of intersegmental contact between thigh–calf and heel–gluteal structures on tibial contact forces. This model includes direct tracking and 3D orientation of intersegmental contact force, femoral translations from in vivo studies, wrapping of knee extensor musculature, and a novel optimization constraint for multielement muscle groups. Model verification consisted of calculating the error between estimated tibial compressive forces and direct measurements from the Grand Knee Challenge during movements to ∼120° of knee flexion as no high knee flexion data are available. Tibial compression estimates strongly fit implant data during walking (R2 =.83) and squatting (R2 =.93) with a root mean squared difference of.47 and.16 body weight, respectively. Incorporating intersegmental contact significantly reduced model estimates of peak tibial anterior–posterior shear and increased peak medial–lateral shear during the static phase of high knee flexion movements by an average of.33 and.07 body weight, respectively. This model supports prior work in that intersegmental contact is a critical parameter when estimating tibial contact forces in high knee flexion movements across a range of culturally and occupationally relevant postures. [ABSTRACT FROM AUTHOR]

This study aimed to identify differences in ground impact shock attenuation between overweight and healthy-weight children during running. Twenty overweight children aged 8.4 (1.1) years and 12 healthy-weight children aged 10.7 (1.3) years ran on a treadmill (120% of baseline speed) while wearing 2 inertial sensors located on their distal tibia and lower back (L3). Peak acceleration attenuation coefficient at foot contact and transfer function of the acceleration were calculated. Peak positive acceleration values were not significantly different between the overweight children and healthy-weight children (3.98 [1.17] g and 3.71 [0.84] g, respectively, P =.49). Children with healthy weight demonstrated significant greater attenuation as evident by greater peak acceleration attenuation coefficient (35.4 [19.3] and 11.9 [27.3], respectively, P <.05) and lower transfer function of the acceleration values (−3.8 [1.9] and −1.2 [1.5], respectively, P <.05). Despite the nonsignificant differences between groups in tibia acceleration at foot–ground impact that was found in the current study, the shock absorption of overweight children was reduced compared with their healthy-weight counterparts. [ABSTRACT FROM AUTHOR]

Background: At present, not all Type AO/OTA 42A2 open fractures can be treated by external fixation brackets, not to mention the inconvenience of this technique in clinical practice. External titanium alloy locking plates, which are lightweight and easy-to-operate, can be used as an alternative treatment option for such patients. However, there are few reports of finite element biomechanical analysis on the titanium alloy locking plates and fixation brackets being placed on the medial side of the tibial fracture. In this study, the biomechanical properties of titanium alloy locking plates and fixation brackets for treating Type AO/OTA 42A2 fractures were compared by applying the finite element method, and the results provided data support for the clinical application of the external titanium alloy locking plate technique. Methods: Type AO/OTA 42A2 fracture models were constructed using CT data of a male volunteer for two external fixation techniques, namely the external titanium alloy locking plate technique and the external fixation bracket technique, according to commonly-used clinical protocols. Then, the four-point bending, axial compression, clockwise rotation and counterclockwise rotation tests under the maximum load were simulated in finite element analysis software. The stress distribution, peak stress and overall tibial displacement data for the two different external fixation techniques were obtained and compared. Results: In the four different test conditions (i.e., four-point bending, axial compression, clockwise torsion, counterclockwise torsion) under the maximum load, the two external fixation techniques showed obvious von Mises stress concentration at the contacts between the screw and tibia, between the screw and titanium alloy locking plate, between the self-tapping self-drilling needle and tibia, between the self-tapping self-drilling needle and the external fixation device, as well as around the fracture end and around the cortical bone at the upper and lower ends of the tibia. The peak stress was ranged 26.67–558.77 MPa, all below the yield stress strength of titanium alloy. The peak tibial displacement of the external titanium alloy locking plate model was smaller than that of the fixation bracket model. In terms of structural stability, the external titanium alloy locking plate technique was superior to the external fixation bracket technique. Conclusions: When fixing Type AO/OTA 42A2 fractures, external titanium alloy locking plates are not only lightweight and easy-to-operate, but also have better performance in terms of axial compression, bending and torsion resistance. According to the finite element biomechanical analysis, external titanium alloy locking plates are superior to traditional external fixation brackets in treating Type AO/OTA 42A2 fractures and can better meet the needs of clinical application. [ABSTRACT FROM AUTHOR]

Background: This study aimed to analyze quantitative correlation between the posterior malleolus fracture and fixation and the rotational stability of the ankle and to explore supplementary surgical indications for posterior malleolus fracture. Methods: Twenty fresh frozen cadaver specimens were selected and dissected. Based on the tibial insertion of the ligament complex, the model for the supination external rotation stage 3 ankle fracture with a posterior malleolar fragment and syndesmosis diastasis was created. The area threshold of the posterior tibial insertion of posterior malleolus fracture was biomechanically assessed and the difference of the antirotating ability stiffness of the ankle between simple posterior malleolus fixation and simple syndesmotic fixation was analyzed statistically. Results: The tibial insertion of posterior inferior tibiofibular ligament and inferior transverse tibiofibular ligament complex was relatively broad, and its width decreased as the distance from the joint line increased. Biomechanical analysis showed that: the threshold of posterior area of posterior malleolus fracture was 1/4S; posterior malleolus fixation provided better rotational stability than syndesmotic fixation (P < 0.01). Conclusion: The surgical indications for posterior malleolus fracture should consider simultaneously the restoration of the axial and rotational stability of the ankle. Simple posterior malleolus fracture fixation is recommended when the syndesmosis is unstable and the area ratio of posterior tibial insertion of posterior malleolus fracture is greater than or equal to 1/4. Syndesmotic fixation is proposed to restore and maintain the rotational stability of the ankle when the syndesmosis is unstable and the area ratio is less than 1/4. Regardless of the area ratio, the surgical indication only depends on the impact of the posterior malleolus fracture on the axial stability of tibiotalar joint, the involved articular surface area, and the displacement degree of posterior malleolus fragment, when the syndesmosis is stable. [ABSTRACT FROM AUTHOR]

Background: There are no definitive anatomic morphometric risk factors for adolescent anterior cruciate ligament (ACL) injury. Purpose: To compare the parameters used to define the tibial and femoral morphometric structure of the knee between adolescent patients with and without ACL rupture. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were magnetic resonance imaging (MRI) scans and radiographs of 115 patients aged 10 to 17 years who were evaluated for ACL rupture at a single institution between February 1, 2019, and January 31, 2022. Images from 115 patients with intact MRI scans were included as controls. We investigated the following imaging parameters: tibial slope (on lateral radiograph), lateral condylar height, tibial sulcus height, medial condylar height, condylar width, intercondylar notch with, intercondylar notch angle, notch index, eminence width, tibial plateau width, eminence width/tibial plateau width, medial/lateral/overall eminence height, medial plateau depth, and 2 different eminence angles. Parameters were compared between groups using the chi-square, Fisher exact, Student t, or Mann-Whitney U test, as appropriate. Receiver operating characteristic analysis was conducted for cutoff values of significant parameters. Results: There were no significant differences in age, sex, or side affected between groups. Only the medial plateau depth was found to be statistically significant between the ACL rupture and ACL intact groups (2.6 vs 2.2 mm; P =.015). A statistically significant cutoff value could not be obtained for the medial plateau depth. Conclusion: Medial plateau depth was found to be significantly greater in adolescent patients with ACL rupture compared with ACL-intact controls. [ABSTRACT FROM AUTHOR]

Background: Coronal and sagittal malalignment of the knee are well-recognized risk factors for failure after anterior cruciate ligament (ACL) reconstruction (ACLR). However, the effect of axial malalignment on graft survival after ACLR is yet to be determined. Purpose: To evaluate whether increased tibiofemoral rotational malalignment, namely, tibiofemoral rotation angle (TFA) and tibial tubercle–trochlear groove (TT-TG) distance, is associated with graft failure after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: In this retrospective matched control study of a single center's database, 151 patients who underwent revision ACLR because of graft failure (ACLR failure group, defined as symptomatic patients with anterior knee instability and an ACL graft tear appreciated on magnetic resonance imaging [MRI] and confirmed during arthroscopic surgery) were compared with a matched control group of 151 patients who underwent primary ACLR with no evidence of failure after ≥2-year follow-up (intact ACLR group). Patients were matched by sex, age, and meniscal injury during primary ACLR. Axial malalignment was assessed on preoperative MRI through the TFA and the TT-TG distance. Sagittal alignment was measured through the posterior tibial slope on MRI. The optimal TFA cutoff associated with graft failure was identified by a receiver operating characteristic curve. The Kaplan-Meier curve with log-rank analysis was performed to evaluate the influence of the TFA on ACLR longevity. Results: The mean age was 25.7 ± 10.4 years for the ACLR failure group and 25.9 ± 10.0 years for the intact ACLR group. Among all the included patients, 174 (57.6%) were male. In the ACLR failure group, the mean TFA was 5.8°± 4.5° (range, −5° to 16°), while it was 3.0°± 3.3° (range, −3° to 15°) in the intact ACLR group (P <.001). Neither the TT-TG distance nor the posterior tibial slope presented statistical differences between the groups. The receiver operating characteristic curve suggested an optimal TFA cutoff of 4.5° for graft failure (area under the curve = 0.71; P <.001; sensitivity, 68.2%; specificity, 75.5%). Considering this a threshold, patients who had a TFA ≥4.5° had 6.6 times higher odds of graft failure compared with patients with a TFA <4.5° (P <.001). Survival analysis demonstrated a 5-year survival rate of 81% in patients with a TFA <4.5°, while it was 44% in those with a TFA ≥4.5° (P <.001). Conclusion: An increased TFA was associated with increased odds of ACLR failure when the TFA was ≥4.5°. Measuring the TFA in patients with ACL tears undergoing reconstruction may inform the surgeon about additional factors that may require consideration before ACLR for a successful outcome. [ABSTRACT FROM AUTHOR]

Tibial plafond (pilon) fractures are uncommon kinds of bone fractures that are difficult to manage and critical to classify. They are considered an enormous challenge for orthopedic surgeons and rehabilitation staff, especially when comminuted at the articular surface and anatomically irreducible. We present a case of high-energy tibial pilon fracture with CT-guided classification and Ilizarov method management. Although it could not reach anatomical reduction due to severe articular comminution, it yielded a functional clinical outcome after a short period of apparatus removal. [ABSTRACT FROM AUTHOR]

Background: Sagittal stability in total knee arthroplasty is achieved through complex processes enabled by prosthetic design and intraoperative soft tissue balancing. This study investigated the effects of preserving medial soft tissue on sagittal stability in bicruciate stabilized total knee arthroplasty (BCS TKA). Method: This retrospective study included 110 patients who underwent primary BCS TKA. The patients were divided into two groups: 44 TKAs were performed releasing medial soft tissue (CON group), and 66 TKAs were performed preserving medial soft tissue (MP group). We assessed joint laxity using tensor device and anteroposterior translation immediately after surgery using the arthrometer at 30° knee flexion. Propensity score matching (PSM) was performed according to preoperative demographic and intraoperative medial joint laxity, and further comparisons between the two groups were performed. Result: After PSM analysis, medial joint laxity in the mid-flexion range tended to be smaller in the MP group than in the CONT group, with a significant difference at 60 degrees (CON group: − 0.2 ± 0.9 mm, MP group: 0.8 ± 1.3 mm, P < 0.05). Anteroposterior translation was significantly different between the two cohorts (CON group: 11.6 ± 2.5 mm, MP group: 8.0 ± 3.1 mm, P < 0.001). Conclusion: This study demonstrated the effects of preserving medial soft tissue on postoperative sagittal stability in BCS TKA. We concluded that this surgical procedure enhances postoperative sagittal stability in the mid-flexion range in BCS TKA. [ABSTRACT FROM AUTHOR]

Background: The role of meniscal lesions and repair in combination with anterior cruciate ligament (ACL) injury and reconstruction has not been extensively investigated in vivo and under weightbearing conditions. Purpose: The purposes of this study were to (1) compare the in vivo knee kinematics between patients with ACL tear and those with combined ACL and medial meniscal tears and (2) investigate kinematic differences between isolated ACL reconstruction and ACL reconstruction plus medial meniscal repair (MR). It was hypothesized that concomitant posterior horn medial meniscal tear and ACL deficiency would affect knee internal-external rotation and anterior-posterior translation but MR would restore these parameters. Study Design: Controlled laboratory study. Methods: Nineteen patients who underwent ACL reconstruction were included: 10 had intact menisci (IM group) and 9 had a medial meniscal injury that was repaired during ACL reconstruction using an all-inside technique (MR group). Preoperatively and 18 months postoperatively, active knee kinematics under weightbearing conditions was evaluated during a single-leg squat using a dynamic biplane x-ray imaging system. The general linear model was used to investigate the differences between group (IM vs MR) and time (preoperative vs follow-up) and their interactions. Results: Tibial internal rotation was higher in the MR group than the IM group both before and after surgery (P =.007). Knee valgus rotation was higher in the MR group preoperatively (P <.001), while no differences were found postoperatively because of an increase of valgus rotation in the IM group, which was significant in the descendant phase (P <.001). Preoperatively, the IM group showed a more medial tibial translation compared with the MR group in the descendant phase (P =.006). Conclusion: When performing a single-leg squat, patients with ACL-deficient knees and a medial meniscal tear demonstrated a more valgus rotation, tibial internal rotation, and lateral tibial translation versus those with intact menisci. After ACL reconstruction and MR, these patients demonstrated significantly higher tibial internal rotation when compared with patients who underwent isolated ACL reconstruction. Clinical Relevance: Surgeons should be aware that MR does not fully restore knee kinematics in vivo and under weightbearing conditions in the context of ACL reconstruction. [ABSTRACT FROM AUTHOR]

Historically, mangled extremities were generally treated with a primary amputation. Advancements in surgical repair and reconstruction have increased the possibility of salvage in the limbs damaged by high-energy trauma, with a reasonably functional outcome. The Mangled Extremity Severity Score is a useful guide for evaluating and managing a crushed limb. However, most literature does not support the practicality of any particular scoring system to discriminate between the limbs requiring amputation and those likely to be salvaged successfully. In young patients, without significant comorbidities and borderline injury scores, an earnest attempt at limb salvage should be made. The case report highlights how shared and timely decision-making coupled with the innovative use of the Ilizarov apparatus, in a seemingly distraught situation, led to successful salvage and restoration of function. [ABSTRACT FROM AUTHOR]

Increased midsole deformation can limit exposure to high impact and vibration magnitudes while running. The aim of this study was to evaluate the effect of shoes eliciting different midsole deformation on ground reaction forces, heel impact, soft tissue vibrations and bone vibrations. Forty-eight runners performed a 5-min running task on an instrumented treadmill at a self-selected pace with four different shoes. Midsole horizontal and vertical deformations were quantified with relative displacement of seven reflective markers placed on the midsole of the shoe and tracked by eight optoelectronic cameras. Heel impacts, soft tissue and bone vibrations of lower leg muscle groups, sacrum and head were quantified with tri-axial accelerometers. Continuous wavelet transform was used to assess magnitude and frequency of the acceleration data. Linear mixed models and non-parametric one-dimensional regressions between the accelerometer data and shoe deformation were performed. Greater horizontal and vertical deformations decreased the magnitude (up to 4.6% per mm) and frequency (up to 0.6 Hz per mm) of soft tissue vibrations and bone accelerations. Accelerations of the heel, tibia, gastrocnemius medialis and vastus lateralis were more influenced than the sacrum and head. Increasing midsole deformation could therefore mitigate the risk of injury, while increasing running comfort and smoothness. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted (RA) total knee arthroplasty (TKA) system and to explore whether it could provide superior short-term clinical and radiological outcomes compared with conventional surgery. Methods: In the present retrospective study, 90 patients who underwent RA-TKA were included in robot-assisted system (RAS) group and 90 patients who underwent conventional TKA were included in the conventional group. The duration of surgery and robot-related complications were recorded to evaluate the learning curve through cumulative sum and risk-adjusted cumulative sum methods. The demographic data, preoperative clinical data, preoperative imaging data, duration of surgery, alignment of the prosthesis, lower limb force line alignment, Knee Society score, 10-cm visual analog scale pain score and range of motion were compared between the RAS and conventional groups. In addition, the proficiency group was compared with the conventional group using propensity score matching. Results: RA-TKA was associated with a learning curve of 20 cases for the duration of surgery. There was no significant difference in indicators representing the accuracy of the prosthetic installation between the learning and proficiency phases in RA-TKA group patients. A total of 49 patients in the proficiency group were matched with 49 patients from the conventional group. The number of postoperative hip–knee–ankle (HKA) angle, component femoral coronal angle (CFCA), component tibial coronal angle (CTCA), and sagittal tibial component angle (STCA) outliers in the proficiency phase was lower than that in the conventional group, while deviations of the HKA angle, CFCA, CTCA, and STCA in the proficiency phase were significantly lower than those in the conventional group (P < 0.05). Conclusion: In summary, from the learning curve data, 20 cases are required for a surgeon using a novel seven-axis RA-TKA system to enter the proficiency phase. In the proficiency group, compared with the conventional group using propensity score matching, the RAS was found to be superior to the conventional group in prosthesis and lower limb alignment. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate whether the Akagi line is a reliable anatomic landmark for adjusting the rotational axis of the tibial component in patients with patellofemoral (PF) malalignment. Materials and methods: This retrospective case–control study included 86 patients with PF instability and 129 controls. On the superimposed axial CT images, TT-TG, TT-PCL, nTT-TG, nTT-PCL, knee joint rotation, and the angle between the Akagi line and surgical transepicondylar axis (Akagi/sTEA angle) were measured. In addition, a modified Akagi line, drawn 1 cm medial to the patellar tendon attachment, was defined, and the angle between the new Akagi line and sTEA (mAkagi/sTEA angle) was also measured and compared between groups. Results: There were 86 patients (47 females, 39 males) in the case group and 129 patients (56 females, 73 males) in the control group with a mean age of 35.7 ± 17.9 years and 41.1 ± 18.8 years, respectively (p < 0.001). Radiologic variables of PF alignment (TT-TG, TT-PCL, nTT-TG, nTT-PCL, and knee joint rotation) were significantly abnormal in the case group (p < 0.001 for all variables). The Akagi/sTEA angle was significantly higher in the case group, resulting in 89.5% external malrotation of the tibial component (> 10°). However, the tibial component was 96.5% aligned correctly (between 10° external and 3° internal rotation) in the control group. Using the modified Akagi line significantly improved the rotational alignment, and normal tibial rotation increased to 93.3% of the case group. The Akagi/sTEA angle strongly correlated with the knee rotation (rho: 0.735, p: 0.001), TT-TG (rho: 0.715, p: 0.001) and nTT-TG (rho: 0.783, p: 0.001). But the TT-PCL (rho: 0.459, p: 0.001) and nTT-PCL (rho: 0.589, p: 0.001) had a medium correlation. Conclusions: The Akagi line might cause unacceptable external rotation of the tibial component in patients with PF malalignment. The use of the modified Akagi line described in this study may be a solution for the rotational mismatch between femoral and tibial components in TKA. Level of evidence: Level III, retrospective case–control study. [ABSTRACT FROM AUTHOR]

Background: Patellar instability is a common knee pathology in skeletally immature patients. In skeletally mature populations, a tibial tubercle–trochlear groove (TT-TG) distance of ≥20 mm is generally considered a pathological value. However, as pediatric patients grow and as the TT-TG distance varies with age, applying the same cutoff value as adult patients to them is unreasonable. Purpose/Hypothesis: This study aimed to analyze the normative values of the TT-TG and tibial tubercle–posterior cruciate ligament (TT-PCL) distances in children with no patellofemoral instability and to propose the cutoff value of the TT-TG and TT-PCL distances predictive of increased risk of patellofemoral instability in pediatric patients. We hypothesized that the TT-TG and TT-PCL distances increase with age in children and adolescents. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance imaging scans of the knee were collected from the patellar instability group and the control group. The TT-TG and TT-PCL distances were measured. The normalized values of the TT-TG and TT-PCL distances were calculated by dividing them by the femoral width. Segmented analysis with 1 breakpoint was performed for both the TT-TG and the TT-PCL distances. The optimal cutoff values of the TT-TG and TT-PCL distances were calculated by maximizing the sum of the sensitivity and specificity. Results: A total of 87 patients had patellar instability, and 509 patients did not. The median values of TT-TG and TT-PCL distances in the control group (8.18 mm and 19.48 mm, respectively) were significantly smaller than those in the instability group (16.10 mm and 24.41 mm, respectively). For those aged <15 years, the TT-TG distance significantly increased by 0.39 mm as the age increased by 1 year. The TT-PCL distance increased by 1.14 mm/year until the age of 11 years. In our cohort, the cutoff value of the TT-TG distance of 14.90 mm yielded 66% sensitivity and 81.9% specificity for predicting an increased risk of patellar instability. The cutoff value of the TT-PCL distance of 23.68 mm yielded 63.9% sensitivity and 65.3% specificity for predicting an increased risk of patellar instability. Conclusion: In our cohort of 596 participants, we have documented the normative values of the TT-TG and TT-PCL distances in children aged <20 years. During the surgery for patellar instability in pediatric patients, orthopaedic surgeons should consider the normative values of the TT-TG and TT-PCL distances according to age to determine which patients need distal realignment surgery. [ABSTRACT FROM AUTHOR]

Background: It is not known mechanistically whether a steeper lateral posterior tibial slope (LTS) leads to an increase in anterior tibial translation (ATT) as well as internal tibial rotation (ITR) during a given jump landing. Hypothesis: A steeper LTS will result in increased ATT and ITR during simulated jump landings when applying knee compression, flexion, and internal tibial torque of increasing severity. Study Design: Descriptive laboratory study. Methods: Seven pairs of cadaveric knees were harvested from young male adult donors (mean ± SD; age, 25.71 ± 5.53 years; weight, 71.51 ± 4.81 kg). The LTS of each knee was measured by a blinded observer from 3-T magnetic resonance images. Two sets of 25 impact trials of ∼700 N (1× body weight [BW] ±10%) followed by 2 sets of 25 trials of 1400 N (2× BW ±10%) were applied to a randomly selected knee of each pair. Similarly, on the contralateral knee, 2 sets of 25 impact trials of ∼1800 N (2.5× BW ±10%) followed by 2 sets of 25 trials of ∼2100 N (3× BW ±10%) were applied. Three-dimensional knee kinematics, including ATT and ITR, were measured at 400 Hz using optoelectronic motion capture. Two-factor linear mixed effect models were used to determine the relationship of LTS to ATT and ITR as impact loading increased. Results: As LTS increased, so did ATT and ITR during increasingly severe landings. LTS had an increasing effect on ATT (coefficient, 0.50; 95% CI, 0.29-0.71) relative to impact force (coefficient, 0.52; 95% CI, 0.50-0.53). ITR was proportional to LTS (coefficient, 1.36; 95% CI, 0.80-1.93) under increasing impact force (coefficient, 0.49; 95% CI, 0.47-0.52). For steeper LTS, the increase in ITR was proportionally greater than the increase in ATT. Conclusion: In male knee specimens, a steeper LTS significantly increased ATT and ITR during jump landings. Clinical Relevance: Increases in ITR and ATT during jump landings lead to increased strain on the anterior cruciate ligament and are therefore associated with greater risk of ligament failure. [ABSTRACT FROM AUTHOR]

Background: Research has demonstrated that performing a secondary task during a drop vertical jump (DVJ) may affect landing kinetics and kinematics. Purpose: To examine the differences in the trunk and lower extremity biomechanics associated with anterior cruciate ligament (ACL) injury risk factors between a standard DVJ and a DVJ while heading a soccer ball (header DVJ). Study Design: Descriptive laboratory study. Methods: Participants comprised 24 college-level soccer players (18 female and 6 male; mean ± SD age, 20.04 ± 1.12 years; height, 165.75 ± 7.25 cm; weight, 60.95 ± 8.47 kg). Each participant completed a standard DVJ and a header DVJ, and biomechanics were recorded using an electromagnetic tracking system and force plate. The difference (Δ) in 3-dimensional trunk, hip, knee, and ankle biomechanics between the tasks was analyzed. In addition, for each biomechanical variable, the correlation between the data from the 2 tasks was calculated. Results: Compared to the standard DVJ, performing the header DVJ led to significantly reduced peak knee flexion angle (Δ = 5.35°; P =.002), knee flexion displacement (Δ = 3.89°; P =.015), hip flexion angle at initial contact (Δ = −2.84°; P =.001), peak trunk flexion angle (Δ = 13.11°; P =.006), and center of mass vertical displacement (Δ = −0.02m; P =.010), and increased peak anterior tibial shear force (Δ = −0.72 N/kg; P =.020), trunk lateral flexion angle at initial contact (Δ = 1.55°; P <.0001), peak trunk lateral flexion angle (Δ = 1.34°; P =.003), knee joint stiffness (Δ = 0.002 N*m/kg/deg; P =.017), and leg stiffness (Δ = 8.46 N/kg/m; P =.046) compared to those in standard DVJs. In addition, individuals' data for these variables were highly and positively correlated between conditions (r = 0.632-0.908; P <.001). Conclusion: The header DVJ task showed kinetic and kinematic parameters that suggested increased risk of ACL injury as compared with the standard DVJ task. Clinical Relevance: Athletes may benefit from acquiring the ability to safely perform header DVJs to prevent ACL injury. To simulate real-time competition situations, coaches and athletic trainers should incorporate such dual tasks in ACL injury prevention programs. [ABSTRACT FROM AUTHOR]

Background: High-impact loads have been linked with running injuries. Fatigue has been proposed to increase impact loads, but this relationship has not been rigorously examined, including the associated role of muscle strength, power, and endurance. Purpose: This study aimed to investigate the effect of fatigue on impact loading in runners and the role of muscle function in mediating changes in impact loading with fatigue. Methods: Twenty-eight trained endurance runners performed a fixed-intensity time to exhaustion test at 85% of V̇O2max. Tibial accelerations were measured using leg-mounted inertial measurement units and sampled every minute until volitional exhaustion. Tests of lower limb muscle strength, power, and endurance included maximal isometric strength (soleus, knee extensors, and knee flexors), single leg hop for distance, and the one leg rise test. Changes in peak tibial acceleration (PTA, g) were compared between time points throughout the run (0%, 25%, 50%, 75%, and 100%). Associations between the change in PTA and lower limb muscle function tests were assessed (Spearman's rho [ r s]). Results: PTA increased over the duration of the fatiguing run. Compared with baseline (0%) (mean ± SD, 9.1 g ± 1.6 g), there was a significant increase at 75% (9.9 g ± 1.7 g , P = 0.001) and 100% (10.1 g ± 1.8 g , P < 0.001), with no change at 25% (9.6 g ± 1.6 g , P = 0.142) or 50% (9.7 g ± 1.7 g , P = 0.053). Relationships between change in PTA and muscle function tests were weak and not statistically significant (r s = −0.153 to 0.142, all P > 0.05). Conclusions: Peak axial tibial acceleration increased throughout a fixed-intensity run to exhaustion. The change in PTA was not related to performance in lower limb muscle function tests. [ABSTRACT FROM AUTHOR]

Introduction: Treadmills have been widely used for training and performance testing during which the treadmill grade is usually set to 0%–2% grade. The purpose of our study was to compare the level of activation of lower body muscles when running at two speeds in an overground condition and on a treadmill at 0%, 1%, and 2% grades. Methods: We recorded EMG data of eight lower body muscles from 13 recreationally active individuals during overground and treadmill running at 2.92 and 4.58 m·s−1. Maximal voluntary contraction (MVC) tests were performed (3 × 6 s) to identify maximal torque and EMG values. The stride cycles, from one foot strike to the next, were identified using a pair of triaxial accelerometers. A two-way repeated-measures ANOVA was used to examine the differences in EMG activity across running conditions and speeds. Cohen's d effect size was calculated to indicate the difference between the overground and the treadmill running conditions. Results: The effect sizes were moderate to negligible for differences between the EMG integral values for overground running and the three treadmill grades. The coefficient of variation for stride time during overground running was significantly larger than that of the treadmill running at 4.58 m·s−1. Conclusions: The results showed that the overall EMG profiles of the thigh and shank muscles were similar for the overground and treadmill conditions, but the similarity was greatest for thigh muscles when running on the treadmill at 1% grade and for shank muscles at 2% grade. The variability in stride time was greater during overground running than when running on a treadmill and was associated with elevated EMG activity of some muscles. [ABSTRACT FROM AUTHOR]