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Context: Anterior cruciate ligament injuries are directly related to the control of dynamic knee valgus in the landing of a jump, and this is mainly due to the correct activation and neuromuscular function of the lower-extremity muscles. The aim of the study is to assess the relationship between lower limb muscle activity during a single-legged drop jump and knee frontal plane projection angle (FPPA). Design: A correlation study. Methods: Thirty healthy collegiate female athletes were included in the study. Main outcomes measures were peak knee FPPA and muscle activity (% of maximal voluntary isometric contraction). Peak knee FPPA during a single-legged drop jump test was identified using a 2-dimensional motion analysis system. Muscle activity was assessed using a surface electromyograph for gluteus maximus, gluteus medius, biceps femoris, semitendinosus, vastus medialis quadriceps, vastus lateralis quadriceps, medial gastrocnemius, and lateral gastrocnemius. All variables were assessed for both dominant and nondominant limbs. A correlation analysis between peak knee FPPA and muscle activity was performed. Statistical significance was set at P <.05. Results: A mean peak knee FPPA of 14.52° and 13.38° was identified for dominant and nondominant limb single-legged drop jump test, respectively. Muscle activity (% of maximal voluntary isometric contraction) for muscles assessed ranged from 43.97% to 195.71% during the single-legged drop jump test. The correlation analysis found no significant correlation between any of the muscles assessed and peak knee FPPA during the single-legged drop jump test (Pearson coefficient between −.3 and.1). Conclusions: There is no association between muscle activity from the lower limb muscles and the knee FPPA during a single-legged drop jump in female athletes. Thus, different muscle properties should be assessed in order to understand such an important movement as the knee FPPA during a jump. [ABSTRACT FROM AUTHOR]

The aim of the present review is to systematically analyse the current literature about gender differences in hip or knee cartilage composition and degeneration, to help explaining how and why osteoarthritis affects women more often and more severely than men. A systematic review of the literature in English was performed. Eleven studies on 1962 patients (905 females and 787 males) that reported differences on cartilage composition between males and females were included. Nine evaluated the knee, one the hip, and one both. They were heterogeneous in their methods: one conducted histological analyses, and all the others evaluated cartilage characteristics (volume, width, and composition) through magnetic resonance imaging. All authors reported gender differences in both volume and morphology of the cartilage, from infancy to menopause. In fact, a study on 92 healthy children statistically showed significant gender differences in cartilage thickness at all sites, even after adjustment for age, body, and bone size. Gender differences become more evident after menopause, when women have a lower cartilage volume and a higher cartilage loss. Men show significantly higher knee and hip cartilage volumes than women, and women carry a significantly greater risk to develop osteoarthritis. This is in part due to body and bone size, but also depends on qualitative and quantitative differences in the composition of cartilage and its degeneration rate after menopause. Structural changes in cartilage that occur between genders during ageing have significance in the development of osteoarthritis. [ABSTRACT FROM AUTHOR]

Tendon properties impact human locomotion, influencing sports performance, and injury prevention. Hamstrings play a crucial role in sprinting, particularly the biceps femoris long head (BFlh), which is prone to frequent injuries. It remains uncertain if BFlh exhibits distinct mechanical properties compared to other hamstring muscles. This study utilized free‐hand three‐dimensional ultrasound to assess morphological and mechanical properties of distal hamstrings tendons in 15 men. Scans were taken in prone position, with hip and knee extended, at rest and during 20%, 40%, 60%, and 80% of maximal voluntary isometric contraction of the knee flexors. Tendon length, volume, cross‐sectional area (CSA), and anteroposterior (AP) and mediolateral (ML) widths were quantified at three locations. Longitudinal and transverse deformations, stiffness, strain, and stress were estimated. The ST had the greatest tendon strain and the lowest stiffness as well as the highest CSA and AP and ML width strain compared to other tendons. Biceps femoris short head (BFsh) exhibited the least strain, AP and ML deformation. Further, BFlh displayed the highest stiffness and stress, and BFsh had the lowest stress. Additionally, deformation varied by region, with the proximal site showing generally the lowest CSA strain. Distal tendon mechanical properties differed among the hamstring muscles during isometric knee flexions. In contrast to other bi‐articular hamstrings, the BFlh high stiffness and stress may result in greater energy absorption by its muscle fascicles, rather than the distal tendon, during late swing in sprinting. This could partly account for the increased incidence of hamstring injuries in this muscle. [ABSTRACT FROM AUTHOR]

Purpose: The present study aims to report the arthroscopic, radiological and clinical appearance of a rare anatomical variation of a hypertrophied medial parapatellar plica with its response to arthroscopic treatment. Case presentation: A 14-year-old female handball athlete presented with a history of left knee injury during her participation in a handball training session and subsequent locked knee at 20º flexion. Tenderness was located at the medial joint line. Plain radiographs of the injured knee were normal. The magnetic resonance imaging revealed a hypertrophic medial parapatellar plica and a horizontal tear of the medial meniscus. A standard knee arthroscopy was performed. An extremely hypertrophied medial plica was identified, covering a great part of the medial femoral condyle extending up to the femoral trochlea. Distally, it was attached into the inter-meniscal ligament. The plica was excised and the medial meniscus tear was repaired. At 1-month post-operatively, the patient was completely asymptomatic and at 3-months she returned to her weekly training routine. Conclusions: This study presented a rare anatomical variation of a hypertrophied medial parapatellar plica with atypical course in the medial patellofemoral compartment and insertion into the inter-meniscal ligament. In combination with a medial meniscus tear led to a locked knee. Arthroscopic medial meniscus repair and plica excision resulted in complete resolution of symptoms. [ABSTRACT FROM AUTHOR]

Background: The medial knee structures have a primary role in stabilizing valgus and rotational stress, which makes them important in assessing the ligament-injured knee globally and choosing the most adequate treatment. Purpose: To conduct a layer-by-layer dissection of the knee’s anteromedial side and provide a qualitative and quantitative description of the anatomy and histology of a ligament in the anteromedial region of the knee, which we have termed the anterior oblique ligament (AOL). Also, to describe the AOL relationship with what we have termed the medial cross—a ligament complex that stabilizes the medial pivot. Study Design: Descriptive laboratory study. Methods: A total of 35 fresh-frozen knees from transfemoral amputations that were exclusively performed for vascular reasons were dissected. Structures were identified after meticulous dissection, respecting the same protocol, measured with a digital caliper rule, and histologically studied for data. Results: The AOL was found in all dissected knees, with a mean length of 31.47 ± 5.06 mm. This structure presented a ligament histology with densely organized collagen fibrils. The medial cross was represented by the superficial medial collateral ligament, AOL (anterior region), and posterior oblique ligament. Conclusion: This study demonstrated the presence of a ligament in the anteromedial region of the knee, termed the AOL. This structure was in the anterior part of a ligament complex—the medial cross. Clinical Relevance: Studying and revisiting the medial compartment can provide important information for understanding joint instability and promoting better results in ligament reconstructions. [ABSTRACT FROM AUTHOR]

The intra-articular popliteal tendon (iPT) is responsible for the dynamic stability of the posterolateral part of the knee joint. In this study, the involvement of the iPT in posterolateral stability in response to knee flexion was investigated anatomically. Thirty-one knees from thirty formalin-fixed room cadavers (17 male knees, 14 female knees; average age 86.9 years) were used. The knee was prepared with the distal 1/3 of the lower femur and crus and was flexed at 0°, 30°, 60°, and 90° in a special jig to limit knee rotation. The series of movements was plotted on the coordinate system using the Quadrant method. The iPT was in strong contact with a thick cartilage area, which we called the "popliteal eminence", at the lateral condyle of the femur. The average iPT angles with respect to the femoral axis were 28.78°, 49.79°, 77.74°, and 115.44° at knee flexion of 0°, 30°, 60°, and 90°, respectively. The iPT was strongly associated with the popliteal eminence at 29.5° in Type I and 27.09° in Type II knee flexion. The iPT has been conventionally regarded as a secondary restraint of posterior movement, acting as a stabilizer. However, the iPT appears to work more positively on knee joint stability because it was in strong enough contact to create the popliteal eminence. The iPT supports the femur in the posterolateral region in mild knee flexion. [ABSTRACT FROM AUTHOR]

Background: Detailed knowledge of the anatomic course of the common peroneal nerve (CPN) is crucial for the surgical treatment of the posterolateral corner (PLC) of the knee. Purpose: To investigate the relationship of the CPN to the PLC of the knee at different flexion angles. Study Design: Descriptive laboratory study. Methods: Ten healthy volunteers were recruited to undergo magnetic resonance imaging (MRI) of the knee joint at knee flexion angles of 0°, 30°, 60°, 90°, and 120°. MRI scans at 3 levels (joint line, tibial cut, and fibular tip) were evaluated to determine (1) the distance from the CPN to the PLC and (2) the distances between the CPN and the anterior-posterior and medial-lateral tibial axes. A 3-dimensional model of the knee joint created from MRI scans of a single participant was used to simulate the creation of a fibular tunnel for PLC reconstruction and investigate the relationship between the CPN, fibular tunnel, and guide pin. Results: The CPN moved posteromedially with increased knee flexion angles. As the flexion angle increased, the distances from the CPN to the anterior-posterior axis and the PLC increased significantly, while the distance to the medial-lateral axis decreased significantly at all 3 measurement levels. The distances between the CPN and anterior-posterior and medial-lateral axes were significantly different among the different knee flexion angles at the different measurement levels. There were no significant differences in the mean distance from the CPN to the posterolateral border of the tibial plateau between 0° and 30° of flexion at the fibular tip level (P =.953). There were statistically significant differences in the distance from the CPN to the PLC of the tibial plateau at the different measurement levels. The 3-dimensional model demonstrated that the position of the CPN relative to the guide pin and the bone tunnel undergoes changes during knee flexion. Conclusion: Changes in the knee flexion angle produced corresponding changes in the course of the CPN on the posterolateral aspect of the knee joint. The CPN moved posteromedially with increased knee flexion angles. Clinical Relevance: Increasing the knee flexion angle during PLC reconstruction can effectively avoid direct injury of the CPN. [ABSTRACT FROM AUTHOR]

Background: Biomarkers collected in synovial tissue and fluid have been identified as potential predictors of outcomes after arthroscopy. Purpose: To provide a narrative review of the current literature that assesses the associations between preoperative biomarkers in the synovial fluid or synovial tissue and patient outcomes after knee arthroscopy. Study Design: Narrative review. Methods: We searched the PubMed database with keywords, "biomarkers AND arthroscopy," "biomarkers AND anterior cruciate ligament reconstruction," and "biomarkers AND meniscectomy." To be included, studies must have collected synovial fluid or synovial tissue from patients before or during arthroscopic knee surgery and analyzed the relationship of biomarkers to postoperative patient outcomes. Biomarkers were classified into 4 main categories: metabolism of aggrecan in cartilage, metabolism of collagen in cartilage (type II collagen), noncollagenous proteins in the knee, and other. When biomarker levels and outcomes were expressed with continuous variables, we abstracted the Pearson or Spearman correlation coefficients as the effect measure. If the biomarker values were continuous and the outcomes binary, we abstracted the mean or median biomarker values in those with favorable versus unfavorable outcomes. We calculated effect sizes as the difference between means of both groups divided by the standard deviation from the mean in the group with better outcomes. Results: Eight studies were included in the review. Each study reported different patient outcomes. Biomarkers associated with metabolism of aggrecan, type II collagen metabolism, and noncollagenous proteins as well as inflammatory biomarkers had statistically significant associations with a range of patient outcomes after knee arthroscopy. Difference across studies in sample size and outcome measures precluded choosing a single biomarker that best predicted patient outcomes. Conclusion: The findings suggest that biomarkers associated with metabolism of aggrecan, type II collagen metabolism, noncollagenous proteins, as well as inflammatory biomarkers may help surgeons and their patients anticipate surgical outcomes. [ABSTRACT FROM AUTHOR]

Indications for surgical corrections about the Achilles tendon are increasing as additional measures in reconstructive interventions about the foot. These indications include shortened gastrocnemii, which cause a so-called 'functional pes equinus' and secondary forefoot imbalances, as well as corrections of pes planus and cavus. Surgery about the heel cord may also be indicated for achillodynia and diabetic pressure ulcers. However, there is a lack of evidence that quantifies the results of lengthening procedures about the heel cord. The aim of this study was to quantify the exact changes in calf strength one year after elongating the triceps surae, by measuring flexion forces in 90 degrees knee flexion and knee extension. This study involves 69 patients who were examined for calf strength preoperatively and 1 year after gastrocnemius release. A new device, the Leonardo Mechanograph® (Novotec Medical) was used to measure calf strength. Measurements were performed with the knee flexed and extended. The operated leg had an overall statistically significant reduction in strength after surgery. Changes were similar on the contralateral leg. The difference in force reduction between the operated and non-operated leg was not statistically significant A correlation between measured plantar flexion forces of the foot after a reconstructive foot operation with or without a lengthening procedure about the calf musculature could not be established. Level III: retrospective cohort study. [ABSTRACT FROM AUTHOR]

Aim: Accessory and sesamoid bones are hidden anatomical structures that fulfil a wide variety of functions in the human body. Therefore, studying the nature, formation and dimensions of these structures is of great importance for the medical literature. In our study, we aimed to measure the presence and area (size) of these ossicles. Material and Method: Our study was performed retrospectively on the images of individuals who applied to Ordu University and whose radiological images were obtained. The presence of accessory and sesamoid ossicles (present/absent) and their sizes (measured using the PACS system) were evaluated on radiographs and Computed Tomography (CT) images. The results of the ossicles were divided into gender, age, and bilateral groups. Statistical analyzes were performed with the SPSS program. Results: The most common and largest accessory ossicles in the foot were os peroneum (18.2%), os naviculare accessoria (17.4%), os trigonum (12.1%) and os intermetatarsarum (7.8%). Sesamoid ossicles at the level of the first metatarsophalangeal (mtp) joint of the foot and the first metacarpopgalangeal (mcp) joint of the hand were found to be 100% common. The second most common sesamoid bone in the hand and foot was at the fifth mtp (22.22%) and mcp (68.53%) joints. In the hand, the most common accessory ossicles were os triangulare (6.08%), os radiale externum (2.60%) and os centrale (1.73%). Accessory ossicles (fabella: 19%, cyamella: 17.5%) were found in 25.5% of the knee. Conclusion: Accessory and sesamoid ossicles are most commonly found in the hand, foot, and knee. The presence and size of these ossicles can be both beneficial and harmful. Sesamoids provide mechanical benefit, whereas accessory ossicles can be mistaken for fractures and may lead to unnecessary medical conditions. Knowing the dimensions of these ossicles allows them to be clinically differentiated from avulsion fractures. [ABSTRACT FROM AUTHOR]

The usefulness of Foam Roller (FR) even without a rolling stimulus (e.g., static compression with or without dynamic joint movements) has been recently demonstrated; however, the different effects of these methods remain unclear. Thus, this study aimed to compare and investigate the effects of such FR intervention methods on knee extensors. The dominant knee extensors of 20 male university students were investigated using the following four conditions: control (CON), FR with rolling (FR_rolling), FR with static compression (FR_SC), and FR with static compression + dynamic movement of the knee joint (FR_DM). FR_SC was intervened to compress the muscle belly of the knee extensors. FR_DM involved knee flexion and extension while maintaining the FR_SC condition. Knee flexion ROM, pain pressure threshold (PPT), tissue hardness, and countermovement jump (CMJ) height were outcome variables; they were compared before and immediately after the intervention. The results of this study showed that knee flexion ROM was significantly (p < 0.01) increased in FR_rolling (d = 0.38), FR_SC (d = 0.28), and FR_DM (d = 0.64). Tissue hardness was significantly (p < 0.01) decreased in FR_rolling (d = -0.55), FR_SC (d = -0.28), and FR_DM (d = -0.42). A main effect of time (p < 0.01) was observed in knee flexion ROM, PPT, and tissue hardness, but no change in CMJ was observed. The results of this study suggested that clinicians and athletes could choose any method they like as a warm-up routine. [ABSTRACT FROM AUTHOR]

Musculoskeletal (MSK) ultrasound has emerged as a valuable tool for sports physical therapists in the assessment and treatment of various knee pathologies. Its ability to provide high-resolution images of soft tissue and superficial bone surfaces makes it especially useful for sports physical therapists and orthopedic clinicians. Specifically, MSK-ultrasound is increasingly recognized as a potent tool for the assessment of the femoral trochlea. Its non-invasive nature and dynamic imaging capabilities make it particularly suited for visualizing the femoral trochlea, a critical component in knee function and biomechanics. The use of MSK ultrasound in the evaluating the femoral trochlea provides sports medicine professionals with a dynamic, non-invasive, and cost-effective means to diagnose, and monitor knee-related injuries. This article delves into the utility of MSK ultrasound in the anatomical and functional assessment of the femoral trochlea, elucidating its benefits, limitations, and clinical implications for athletes. [ABSTRACT FROM AUTHOR]

Background: Lateral discoid meniscus accounts for most meniscal tears in children 10 years of age and younger. The role of bony morphology in discoid meniscus has been previously studied in a limited capacity using radiographs. Purpose: To use magnetic resonance imaging to measure features of the femoral condyles and tibial plateaus in patients with discoid meniscus to assess potential determinants of symptoms and subsequent surgery and to compare with matched controls to investigate age-related changes in bony features. Study Design: Cross-sectional study; Level of evidence, 3. Methods: After institutional review board approval, detailed morphology of the femoral condyles and tibial plateau was measured in 177 patients (3-18 years of age; 56% female) with confirmed lateral discoid meniscus. Measurements from 269 participants (3-18 years of age; 55% female) with asymptomatic knees were used as controls. Two-way analysis of variance with Holm-Šídák post hoc was used to compare measurements between discoid menisci and matched controls. Independent t tests were used to compare aspects of bony morphology within the discoid meniscus cohort. Results: Compared with controls, patients with a lateral discoid meniscus had a larger bicondylar width and notch width (7- to 10-year-old and 15- to 18-year-old age groups; P <.05), larger tibial plateau width (11- to 14-year-old and 15- to 18-year-old age groups; P <.001), and smaller lateral (P <.02) and coronal (P <.02) tibial slopes across all age groups. Among patients with a discoid meniscus, larger bicondylar width, larger tibial plateau width, larger notch width, and a flatter lateral femoral condyle were associated with pain (P <.005) and lateral meniscal tears (P <.02). Larger notch width and notch width index were also associated with subsequent surgery (P <.05). Conclusion: There are clinically significant abnormalities in bony morphology in patients with a discoid meniscus, including larger femoral condyles and tibial plateaus and a flatter tibial plateau. Additionally, femoral size, femoral curvature, and tibial plateau size may influence the likelihood of knee pain, meniscal tear, and need for surgery. These findings highlight the importance of bony morphology in discoid meniscus pathophysiology in children and adolescents. Such measurements may also aid radiographic detection of discoid meniscus and guide decisions regarding the timing of potential surgical intervention. [ABSTRACT FROM AUTHOR]

Background: People are increasingly using the Internet to retrieve health information about chronic musculoskeletal conditions, yet content can be inaccurate and of variable quality. Objective: To summarise (i) comprehensiveness, (ii) accuracy and clarity, iii) quality of information about treatment choices, (iv) credibility and (v) readability of online information about knee osteoarthritis. Method: Systematic appraisal of website content. Searches for "knee osteoarthritis" and "knee arthritis" were performed using Google and Bing (October 2020). The top 20 URLs of each search were screened for eligibility. Comprehensiveness, accuracy and clarity of content were matched against 14 pre-defined topic descriptors. DISCERN and HONcode were used to measure quality of information about treatment choices and website credibility, respectively. Flesch Reading Ease and Flesch-Kincaid Grade Level tests were used to assess readability. Results: Thirty-five websites were included. Websites were generally comprehensive (median, range = 12, 0–14/14) with descriptors available for 67% (n = 330/490) of topics across all websites, but only 35% (n = 116/330) were accurate and clear. Quality of information about treatment choices was generally low (median DISCERN score, range = 40, 16–56/80). Credibility descriptors were present for 65% (n = 181/280) of items, with 81% (n = 146/181) of descriptors being clear. Median Flesch reading ease was 53 (range = 21–74), and Flesch-Kincaid grade level was 8 (range = 5–11). Conclusion: Few websites provide accurate and clear content aligned to key research evidence. Quality of information about treatment choices was poor, with large variation in comprehensiveness, credibility and readability. Implications: Careful consideration is required by clinicians to identify what online information people with knee osteoarthritis have accessed and to address misinformed beliefs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rupture of the anterior cruciate ligament (ACL) is one of the most common knee injuries and has substantial impact on knee function. Beside primary ruptures, an increasing number of re-(re-)ruptures occur, representing a therapeutical challenge for the treating surgeon. Several risk factors for re-ruptures have been previously identified, including an increased tibial slope. OBJECTIVE: In this study, we investigated the effect of femoral condyle configuration on ACL-ruptures and re-ruptures. METHODS: In-vivo magnetic resonance imaging scans of three different groups of patients were compared. Group 1 included patients with an intact ACL on both sides, group 2 included patients with primary, unilateral ACL-rupture, while group 3 included patients with an ACL-re-rupture or re-(re-)rupture. Fourteen different variables were obtained and analyzed regarding their impact on ACL-re-(re-)rupture. RESULTS: Overall, 334 knees were investigated. Our data allowed us to define parameters to identify anatomical configurations of bones associated with an increased risk of ACL-re-rupture. Our results show, that patients with ACL-re-rupture show increased radii of the extension facet of the lateral femoral condyle (p < 0.001) as well as of the extension facet of the medial femoral condyle (p < 0.001). CONCLUSION: We conclude that a spherical femoral condyle form does influence the clinical outcome after ACL-reconstruction. [ABSTRACT FROM AUTHOR]

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The frequency of lateral unicompartmental knee arthroplasty is estimated at 1% of the total volume of knee arthroplasties, according to contemporary literature. Recent studies analyzing this type of surgical intervention indicate that when performed with proper indications and technical accuracy, it is equally effective and safe as total knee arthroplasty. Potential advantages of partial knee replacement include reduced invasiveness compared to total knee arthroplasty, lower perioperative blood loss, faster patient rehabilitation, and preservation of native joint proprioception. However, it is important to consider that successful implementation of lateral unicompartmental knee arthroplasty requires not only appropriate patient selection but also technical proficiency, advanced operating room equipment, and precise surgical techniques performed by experienced surgeons. Failure to meet these conditions can negate the potential benefits and may lead to early revision surgery. It is evident that unicompartmental knee arthroplasty is not simply a half-operation of total joint replacement, and the lateral compartments partial arthroplasty only shares general similarities with the more popular and established medial unicompartmental knee arthroplasty. The differences lie primarily in the complex anatomy and biomechanics of the lateral compartment, which present a challenging task even with the use of modern anatomically designed implants. The development of robotic surgery and personalized joint implants may help overcome these challenges more effectively. However, in our current routine practice, we rely on conventional instruments and strive to optimize our techniques. The authors of this article aim to provide an overview of the contemporary understanding of the anatomy and biomechanics of the lateral compartment of the knee and the specific technical aspects related to partial lateral arthroplasty using a fixed tibial platform implant.

Context: Each hamstring muscle is subdivided into several regions by multiple motor nerve branches, which implies each region has different muscle activation properties. However, little is known about the muscle activation of each region with a change in the knee joint angle. Understanding of regional activation of the hamstrings could be helpful for designing rehabilitation and training programs targeted at strengthening a specific region. Objective: To investigate the effect of knee joint angle on the activity level of several regions within the individual hamstring muscles during isometric knee-flexion exercise with maximal effort (MVCKF). Design: Within-subjects repeated measures. Setting: University laboratory. Participants: Sixteen young males with previous participation in sports competition and resistance training experience. Intervention: The participants performed 2 MVCKF trials at each knee joint angle of 30°, 60°, and 90°. Outcome Measures: Surface electromyography was used to measure muscle activity in the proximal, middle, and distal regions of the biceps femoris long head (BFlh), semitendinosus, and semimembranosus of hamstrings at 30°, 60°, and 90° of knee flexion during MVCKF. Results: Muscle activity levels in the proximal and middle regions of the BFlh were higher at 30° and 60° of knee flexion than at 90° during MVCKF (all: P <.05). Meanwhile, the activity levels in the distal region of the BFlh were not different among all of the evaluated knee joint angles. In semitendinosus and semimembranosus, the activity levels were higher at 30° and 60° than at 90°, regardless of region (all: P <.05). Conclusion: These findings suggest that the effect of knee joint angle on muscle activity level differs between regions of the BFlh, whereas that is similar among regions of semitendinosus and semimembranosus during MVCKF. [ABSTRACT FROM AUTHOR]

Novice runners experience a higher incidence of knee injury than experienced runners, which may be related to aberrant frontal and transverse plane kinematics. However, differences in kinematics between novice and experienced runners have not been fully explored. For this study, 10 novice and 10 experienced female runners ran on a treadmill at 2.68 m/s. Ankle, knee, and hip joint angles during the stance phase were measured using a 3-dimensional motion capture system and modeled using cubic splines. Spline models were compared between groups using a generalized linear model (α =.05). Ninety-five percent confidence intervals of the difference between joint angles throughout stance were constructed to identify specific periods of stance where groups differed in joint position. Angle–angle diagrams of ankle and hip position in the frontal and transverse planes were constructed to depict joint coordination. Novice runners displayed less hip adduction, but greater knee abduction and knee internal rotation compared to experienced runners. Differences in knee joint position may be explained by coordination of hip and ankle motion. Greater knee abduction and knee internal rotation displayed by novice runners compared with experienced runners may help to explain their higher risk for injury. [ABSTRACT FROM AUTHOR]

Background: Pre-operative alignment is important for knee procedures including total knee arthroplasty (TKA), especially when considering alternative alignments. The arithmetic Hip Knee Angle (aHKA) is a measure of coronal alignment calculated using the medial proximal tibial (MPTA) and lateral distal femoral angles (LDFA). Traditionally, aHKA is measured on long leg radiographs (LLR). This study assesses the reproducibility of aHKA measurement on LLR and robotic-assisted TKA planning CT. Methods: Sixty-eight TKA patients with pre-operative LLR and planning CTs were included. Three observers measured the LDFA, MPTA and aHKA three times on each modality and intra-observer and inter-observer reliability was calculated. Statistical analysis was undertaken with Pearson's r and the Bland–Altman test. Results: Mean intra-observer coefficient of repeatability (COR) for LLR vs. CT: MPTA 3.50° vs. 1.73°, LDFA 2.93° vs. 2.00° and aHKA 2.88° vs. 2.57° for CT. Inter-observer COR for LLR vs. CT: MPTA 2.74° vs. 1.28°, LDFA 2.31° vs. 1.92°, aHKA 3.56° vs. 2.00°. Mean intra-observer Pearson's r for MPTA was 0.93 for LLR and 0.94 for CT, LDFA 0.90 for LLR and 0.91 for CT and aHKA 0.92 for LLR and 0.94 for CT. Inter-observer Pearson's r for LLR compared to CT: MPTA 0.93 vs. 0.97, LDFA 0.91 vs. 0.90, aHKA 0.91 and 0.95. Conclusion: When compared to LLR, CT measurements of MPTA, LDFA and aHKA are more reproducible and have a good correlation with LLR measurement. CT overcomes difficulties with positioning, rotation, habitus and contractures when assessing coronal plane alignment and may obviate the need for LLRs. [ABSTRACT FROM AUTHOR]

Background: Several tibiofemoral anatomic features have been repeatedly associated with increased anterior cruciate ligament (ACL) injury risk. Previous studies have highlighted age and sex differences among these anatomic risk factors, but little is known about the normal and pathologic development of these differences during skeletal maturation. Purpose: To investigate differences in anatomic risk factors at various stages of skeletal maturation between ACL-injured knees and matched controls. Study Design: Cross-sectional study; Level of evidence, 3. Methods: After institutional review board approval, magnetic resonance imaging scans from 213 unique ACL-injured knees (age, 7-18 years, 48% female) and 239 unique asymptomatic ACL-intact knees (age, 7-18 years, 50% female) were used to measure femoral notch width, posterior slope of the lateral and medial tibial plateau, medial and lateral tibial spinal height (MTSH, LTSH), medial tibial depth, and posterior lateral meniscus-bone angle. Linear regression was performed to assess change in quantified anatomic indices with age for male and female patients in the ACL-injured cohort. Two-way analysis of variance with Holm-Sidak post hoc testing was performed to compare anatomic indices between ACL-injured knees and ACL-intact controls in each age group. Results: In the ACL-injured cohort, notch width, notch width index and medial tibial depth increased with age (R 2 > 0.1; P <.001) in both sexes. MTSH and LTSH increased with age only in boys (R 2≥ 0.09; P ≤.001), whereas meniscus-bone angle decreased with age only in girls (R 2 = 0.13; P <.001). There were no other age differences in quantified anatomic indices. Patients with ACL injury consistently had a significantly higher lateral tibial slope (P <.01) and smaller LTSH (P <.001) as compared with ACL-intact controls across all age groups and sexes. When compared with age- and sex-matched ACL-intact controls, ACL-injured knees had a smaller notch width (boys, 7-18 years; girls, 7-14 years; P <.05), larger medial tibial slope (boys and girls, 15-18 years; P <.01), smaller MTSH (boys, 7-14 years; girls, 11-14 years; P <.05), and larger meniscus-bone angle (girls, 7-10 years; P =.050). Conclusion: The consistent morphologic differences throughout skeletal growth and maturation suggest a developmental role in high-risk knee morphology. The observed high-risk knee morphology at an earlier age preliminarily suggests the potential of knee anatomy measurements in identifying those with a predisposition toward ACL injury. [ABSTRACT FROM AUTHOR]

Malalignment of total knee arthroplasty (TKA) components is a potential cause of clinical failure following TKA. Since the goal of a gap balancing (GB) technique is equal flexion and extension gaps secondary to soft-tissue balancing, and not necessarily component alignment, variation in component placement may exist. Our purpose was (1) to evaluate precision of component alignment in well-functioning GB TKAs performed without the aid of navigation using computed tomographic evaluation and (2) to determine any relationship between femoral version and/or tibial torsion and TKA component positioning. There were 93 well-functioning TKAs performed with an extension gap first GB technique with a minimum 2-year follow-up evaluated using computed tomography to assess component rotational alignment, as well as osseous femoral version and tibial torsion. Femoral and tibial rotational alignment was assessed by previously described methods. The mean Knee Society Score was 185.7 ± 21.7. The mean range of motion was 128.5 ± 7.8°. Femoral posterocondylar axis (relative to the transepicondylar axis) values ranged from −8.3 to 4.1° with a mean of −0.78 ± 2.7° (internal rotation). Mean tibial rotation was 17.2 ± 7.9° internal rotation relative to the tibial tubercle. No correlation was found between native femoral version and femoral component rotational alignment (Pearson's correlation coefficient, r , 0.007). Weak correlation was found between native tibial torsion and tibial component alignment (r = 0.24). Despite being only a secondary objective with the GB technique, most components evaluated were within the desired range of rotation. Alignment was not influenced by native osseous rotational geometry. Level III, Retrospective Cohort Study. [ABSTRACT FROM AUTHOR]

BACKGROUND: Primary school children spend quite a lot of time sitting in classrooms. For this reason, it is necessary to make a scientific analysis of children's body dimensions and compare them with the furniture dimensions where they sit. OBJECTIVES: The main aim of this paper is to present anthropometric data for pupils in primary schools in the Republic of Kosovo and give recommendations for school furniture design. METHODS: Measurements were made in the public schools of four different regions in the Republic of Kosovo. The study includes 720 children from 12 different elementary schools with first and fifth graders (6–11 years old). Twelve body parts were measured: Stature, sitting height, shoulder height, lower leg length, hip breadth, elbow height, buttock-popliteal length, thigh clearance, eye height, shoulder breadth, and knee height. The descriptive data are calculated in terms of average, standard deviation, and 5th, 50th and 95th percentile. RESULTS: We recommend that the competent authorities in the Republic of Kosovo consider improving the infrastructure of primary schools in terms of furniture size according to the findings presented in this study. CONCLUSIONS: The information presented in this paper on pupils' anthropometry and the proposed dimensions for school furniture can be used by various bodies in Kosovo including, but not limited to: Ministry of Education Science and Technology, Ministry of Trade and Industry of Kosovo and furniture manufacturing industries as basic information for suitable furniture design for primary school children, as well as school principals to help in furniture selection. [ABSTRACT FROM AUTHOR]

Introduction: There have been controversial studies on the impact of prior knee arthroscopy (KA) on outcomes of total knee arthroplasty (TKA). The purpose of this comparative study is to investigate the impact of prior KA of medial meniscus on patients undergoing TKA by evaluating the International Knee Society Score (IKS), the complications, and revisions. Methods: This retrospective study reviewed 84 patients with TKA who had undergone prior KA of the medial meniscus and compared them to 84 cases, without a history of prior KA as a control group. Outcomes were assessed with the original IKS scores and complications. The mean follow-up was 8 years. Results: There was no significant difference between groups with respect to demographics, or pre-operative IKS. The mean pre and postoperative IKS was not different between groups. The all-cause reoperation, revision, and complication rates of the KA group were not significantly higher than those of the control group. Conclusion: The present study seems to reveal that previous KA of the medial meniscus does not negatively affect a subsequent TKA. Nevertheless, larger studies may be necessary to confirm this observation.

Both structural and clinical changes can signify knee osteoarthritis progression; however, these changes are not always concurrent. A better understanding of mechanical factors associated with progression and whether they differ for structural versus clinical outcomes could lead to improved conservative management. This study examined baseline gait differences between progression and no progression groups defined at an average of 7-year follow-up using 2 different outcomes indicative of knee osteoarthritis progression: radiographic medial joint space narrowing and total knee arthroplasty. Of 49 individuals with knee osteoarthritis who underwent baseline gait analysis, 32 progressed and 17 did not progress using the radiographic outcome, while 13 progressed and 36 did not progress using the arthroplasty outcome. Key knee moment and electromyography waveform features were extracted using principal component analysis, and confidence intervals were used to examine between-group differences in these metrics. Those who progressed using the arthroplasty outcome had prolonged rectus femoris and lateral hamstrings muscle activation compared with the no arthroplasty group. Those with radiographic progression had greater mid-stance internal knee rotation moments compared with the no radiographic progression group. These results provide preliminary evidence for the role of prolonged muscle activation in total knee arthroplasty, while radiographic changes may be related to loading magnitude. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of β-hydroxy-β-methylbutyrate free acid (HMB-FA) and calcium salt (HMB-Ca) on strength, hypertrophy, and markers of muscle damage. In this randomized, double-blind, placebo-controlled study, 44 resistance-trained men (age: 26 ± 4 years; body mass: 84.9 ± 12.0 kg) consuming ≥1.7 g⋅kg-1•day-1 of protein received HMB-FA (3 g/day; n = 14), HMB-Ca (3 g/day; n = 15), or placebo (PL; cornstarch, 3 g/day; n = 15) for 12 weeks, while performing a periodized resistance training program. Before and after intervention, lean body mass (measured with dual X-ray absorptiometry), maximal dynamic strength (one-repetition maximum), knee extension maximal isometric strength (maximal voluntary isometric contraction [MVIC]), cross-sectional area (measured with ultrasound), and muscle soreness were assessed. MVIC was also measured 48 hr after the first and the last training sessions. All groups increased lean body mass (main time effect: p < .0001; HMB-FA: 1.8 ± 1.8 kg; HMB-Ca: 0.8 ± 1.4 kg; PL: 0.9 ± 1.4 kg), cross-sectional area (main time effect: p < .0001; HMB-FA: 6.6 ± 3.8%; HMB-Ca: 4.7 ± 4.4%; PL: 6.9 ± 3.8%), one-repetition maximum bench press (main time effect: p < .0001; HMB-FA: 14.8 ± 8.4 kg; HMB-Ca: 11.8 ± 7.4 kg; PL: 11.2 ± 6.6 kg), MVIC (main time effect: p < .0001; HMB-FA: 34.4 ± 39.3%; HMB-Ca: 32.3 ± 27.4%; PL: 17.7 ± 20.9%) after the intervention, but no differences between groups were shown. HMB-FA group showed greater leg press strength after the intervention than HMB-Ca and PL groups (Group x Time interaction: p < .05; HMB-FA: 47.7 ± 31.2 kg; HMB-Ca: 43.8 ± 31.7 kg; PL: 30.2 ± 20.9 kg). MVIC measured 48 hr after the first and the last sessions showed no attenuation of force decline with supplementation. Muscle soreness following the first and last sessions was not different between groups. The authors concluded that neither HMB-Ca nor HMB-FA improved hypertrophy or reduced muscle damage in resistance-trained men undergoing resistance training ingesting optimal amounts of protein. HMB-FA but not HMB-Ca resulted in a statistically significant yet minor improvement on leg press one-repetition maximum. [ABSTRACT FROM AUTHOR]

Osgood-Schlatter disease (OSD) and Sinding-Larsen- Johansson disease (SLJD) are commonly diagnosed conditions in young, athletic patients who present with anterior knee pain. Despite the familiarity many clinicians have with OSD because of its frequent diagnosis, it does not differ much from SLJD in clinical presentation. Although these diseases generally are self-limiting, diagnostic imaging studies can help clinicians make the correct diagnosis, helping patients avoid progressing to advanced disease states that would require extended rest time, prolonged pain, and potential surgical intervention. [ABSTRACT FROM AUTHOR]

Background: The presence of a lateral meniscus root tear (LMRT) in patients with an anterior cruciate ligament (ACL) tear makes the knee more unstable and increases the risk of osteoarthritis and osteonecrosis. An all-inside suture repair technique without bone tunnels has been proposed to treat LMRT. Purpose: To compare the 1-year postoperative findings between patients who underwent ACL reconstruction combined with LMRT repair (LMRT group) and patients who underwent isolated ACL reconstruction (control group). Study Design: Cohort study; Level of evidence, 3. Methods: The LMRT group consisted of 19 patients, and the control group consisted of 56 patients. In this study, the authors compared the postoperative magnetic resonance imaging (MRI) findings (meniscal extrusion, ghost sign, and hyperintensity in the tibial plateau beneath the LMRT), functional outcomes (International Knee Documentation Committee [IKDC], Lysholm, and Tegner scores), and reoperation rate between groups. The primary endpoint was analyzed by comparing, in the LMRT group, the 1-sided 97.5% confidence interval (CI) of the mean lateral meniscal extrusion at 1 year to the limit of noninferiority (fixed at 0.51). To take into account imbalanced baseline characteristics between groups, adjusted mean meniscal extrusion (with 1-sided 97.5% CI) was assessed using a linear regression model. Results: The mean follow-up was 12.2 months (range, 7.7-14.7 months) in the control group and 11.5 months (range, 7.1-13.0 months) in the LMRT group (P =.06). For meniscal extrusion, the LMRT group was noninferior to the control group. The mean meniscal extrusion was 2.19 mm (97.5% CI, —infinity to 2.68 mm) in the LMRT group and 2.03 mm (97.5% CI,—infinity to 2.27 mm) in the control group, indicating that the upper boundary of the 1-sided 97.5% CI in the LMRT group was less than the noninferiority threshold of 2.78 (ie, 2.27 mm + 0.51 mm = 2.78 mm). There was a statistically significant difference in the IKDC score between the LMRT and control groups (77.2 ± 8.1 vs 80.3 ± 7.3, respectively; P =.04). There was no between-group difference in the other MRI parameters, the Lysholm and Tegner scores, or the reoperation rate. Conclusion: There was no significant difference in extrusion on MRI or clinical outcomes at 1-year follow-up in patients who underwent ACL reconstruction with all-inside LMRT repair compared with patients who did not have an LMRT. [ABSTRACT FROM AUTHOR]

Mediolateral patella displacement is of interest for diagnostics and clinically relevant research questions. Apart from manual testing, no standardized method is currently available. Proper quantification of patella mobility is necessary to better understand pathologies at the patellofemoral joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new prototype instrument for quantification of the mediolateral patella displacement. The participants underwent measurements of the mediolateral displacement three times using the Patellostabilometer. A maximal force of 10 N was applied for patella movement. Additionally, leg length and circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of 18.27 ± 3.76 mm (range 15.85–20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial patella displacement showed 24.47 ± 6.59 mm (range 19.29–29.76 mm, IQR of 10.47). The test–retest measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater test–retest variability between the measurements of the medial displacement compared to the lateral one. The test–retest variability reached 7% of the patella displacement. Other parameters provided no significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant quantification of patella mobility is allowed. [ABSTRACT FROM AUTHOR]

Background and purpose -- Day-case hip and knee arthroplasty has gained in popularity, but there are conflicting results regarding readmissions. We aimed to investigate differences in 30- and 90-day readmission rates between day-case patients and patients with a single overnight stay following primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA). Patients and methods -- We identified day-case (DC) and overnight (ON) THA, TKA, and UKA patients, operated on between 2010 and 2020, from the Danish National Patient Register. Day-case surgery was defined as discharge on the day of surgery. Overnight readmissions within 30 or 90 days of surgery were considered readmissions. We compared readmission rates between DC and ON patients within arthroplasty types using logistic regression adjusted for patient characteristics and year of surgery. We included 29,486 THAs (1,353 DC and 28,133 ON), 15,116 TKAs (617 DC and 14,499 ON), and 6,440 UKAs (1,528 DC and 4,914 ON). Results -- The 30-day readmission rates were: DC-THA 4.4% vs. ON-THA 4.4% (adjusted odds-ratio [aOR] 1.2, 95% confidence interval [CI] 0.91-1.6), DC-TKA 4.7% vs. ON-TKA 4.4% (aOR 1.1, CI 0.69-1.5), and DC-UKA 3.0% vs. ON-UKA 3.0% (aOR 1.1, CI 0.78-1.5). Similarly, no significant differences were present between DC and ON THA, TKA, and UKA regarding 90-day readmissions or time to readmission. Conclusion -- We found no differences in readmission rates between day-case THA, TKA, and UKA patients and patients with a single overnight stay. [ABSTRACT FROM AUTHOR]

Background: Strength testing is one of the primary assessment tools for physical strength examination, and an increase in strength is the aim of many rehabilitation programs. Manual muscle testing (MMT) is the most commonly used strength testing method in clinical settings. It is a subjective measurement technique whereby the tester applies resistance to a maximum voluntary muscle contraction. The reliability of the Fitmust hand-held dynamometer is not previously reported in the literature. Aims and Objectives: The study aims to test the reliability of the Fitmust hand-held dynamometer for lower limb muscles in comparison with the Jamar Hand Held dynamometer. Methods: Maximum voluntary isometric contraction of hip extension, knee extension, and plantar flexion is measured by two different therapists on different days using fit must handheld dynamometer for 40 healthy participants of age category 18-30 years. Result: Reliability was evaluated by computing Intra-class Correlation Coefficients (ICC), which analyse the consistency between two or more quantitative measures, and Cronbach's Alpha which measured agreement. Conclusion: Inter-tester reliability data obtained for Assessor 1 and 2 were consistent for knee measurements. However, data for the hip and ankle varied considerably. Assessors 1 and 2 demonstrated a 'moderate to excellent' association for knee Measurements. [ABSTRACT FROM AUTHOR]

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Commonly, the monitoring of external workload has been performed using a single device on player's scapulae. The human body is a complex multi-articular system and quantification in a single location is insufficient, being necessary the assessment in multiple body locations simultaneously. Therefore, this study aimed to characterize the multi-location external workload in men's and women's players and to analyze the sex-related differences during the most common movements in basketball. Twenty-six semi-professional basketball players (n = 13 men, n = 13 women) were evaluated in five tests: linear and curvilinear movements, changing of speed, jumping and in-game movements. PlayerLoadRT was evaluated at six anatomical locations simultaneously (scapulae, lumbar region, knees, and ankles) with WIMU PROTM inertial devices attached to the athlete using a full-body skinsuit. Statistical analysis was composed of a t-test of independent measures and Coheńs d effect size. The main results indicated: (1) the type of movement modified the external workload supported by the musculoskeletal structures; (2) sex-related differences were found in the vertical absorption of external workload (p < 0.05); (3) no sex-related differences were shown in the horizontal profile (p > 0.16). The multi-location monitoring will allow the identification of musculoskeletal structures with high vertical absorption of external load depending on sex (men > women: scapulae-lumbar and knee-ankle; women > men: lumbar-knee) and type of movement (scapulae-lumbar: decelerations; lumbar-knee: jumping; knee-ankle: in-game), just like horizontal differences in lower limb (outer > inner leg: curvilinear). Equally movements distribution throughout training sessions, strengthening and recovery programmes of high-workload muscle groups according to player's characteristics could contributed to performance enhancement and reduce injury risk. HIGHLIGHTS Men's and women's basketball players presented different vertical musculoskeletal absorption of external workload. Men presented higher absorption in scapulae – lumbar and knee – ankle segments while women did so in the lumbar – knee segment. The type of movements had a direct effect in the multi-location external workload profile. A combined effect of sex and type of movement was found in the vertical musculoskeletal absorption of the external workload profile. No sex-related differences were found in the horizontal profile regarding the type of movement. [ABSTRACT FROM AUTHOR]

Knee articular geometry and surface morphology greatly affect knee joint mechanics. Intra‐subject variations in bone morphology and the passive range of motion have been well documented in the literature; however, the relationship between these two characteristics is not well understood. The objective of this study was to describe the correlation between knee joint anatomical features and passive range of motion using a statistical model. A principal component model was developed using femoral and tibial articular geometry, knee joint initial stance position, and the passive laxity envelope obtained from 27 cadaveric knees. The results from the principal component analysis showed high correlation between the anatomical features and the tibiofemoral passive envelope; an increase in the average femoral condyle radii, an increase in slope of the tibial spine, and a higher tibial plateau concavity correlated with a decrease in varus−valgus and internal−external range of motion. Understanding the correlation between anatomical features and tibiofemoral laxity could aid in the development of orthopedic implant designs by quantifying the effect of perturbing specific anatomical features on knee laxity and identifying specific implant femoral and tibial articular geometry necessary to obtain a targeted passive range of motion. [ABSTRACT FROM AUTHOR]

Purpose: The current study aims to report the radiologic and clinical appearance of a rare anatomical variation of the knee medial synovial plica along with its response to conservative and surgical treatment. Case presentation: This report portrays a 29-year-old male patient with anteromedial gradual onset right knee pain, aggravated when descending stairs or prolonged sitting. Physical examination revealed medial parapatellar local tenderness, a palpable click in this area when the knee was extended, and hamstring tightness. Magnetic resonance imaging showed a duplicated medial plica, characterized by a high-intensity signal of the infrapatellar fat pad medial portion, after which a presumptive diagnosis of medial plica syndrome was proposed. After conservative treatment failure, the patient underwent standard knee arthroscopy that revealed a superior low profile and an inferior high profile medial plica, and hypertrophy of the medial portion of the infrapatellar fat pad. Both plicae and fat pad were resected with a mechanical shaver until no contact between the femoral trochlea and the fat pad was observed during full range of motion. At 4 weeks postoperatively, symptoms completely resolved, and the patient was allowed to return to full activity with no recurrences at 1 year follow-up. Conclusions: The current study presented a rare anatomical variation of the knee medial synovial plica that was symptomatic and recalcitrant to conservative treatment. This case report may be useful for radiologists and orthopaedic surgeons to differentiate this special plica type and consider its response to conservative and surgical treatment during patient management. [ABSTRACT FROM AUTHOR]

Background: Several fibula-based reconstruction techniques have been introduced to address ligamentous injuries of the posterolateral corner of the knee. These techniques involve a drill tunnel with auto- or allograft placement through the proximal fibula. Purpose: To determine the skeletal microarchitecture of the proximal fibula and its association with age and to compare the microarchitecture within the regions of different drill tunnel techniques for reconstruction of the posterolateral corner. Study Design: Descriptive laboratory study. Methods: A total of 30 human fibulae were analyzed in this cadaveric imaging study. High-resolution peripheral quantitative computed tomography measurements were performed in a 4.5 cm–long volume of interest at the proximal fibula. Three-dimensional microarchitectural data sets of cortical and trabecular compartments were evaluated using customized scripts. The quadrants representing the entry and exit drill tunnel positions corresponding to anatomic techniques (LaPrade/Arciero) and the Larson technique were analyzed. Linear regression models and group comparisons were applied. Results: Trabecular microarchitecture parameters declined significantly with age in women but not men. Analysis of subregions with respect to height revealed stable cortical and decreasing trabecular values from proximal to distal in both sexes. Along with a structural variability in axial slices, superior values were found for the densitometric and microarchitectural parameters corresponding to the fibular drill tunnels in the anatomic versus Larson technique (mean ± SD; bone volume to tissue volume at the entry position, 0.273 ± 0.079 vs 0.175 ± 0.063; P <.0001; cortical thickness at the entry position, 0.501 ± 0.138 vs 0.353 ± 0.081 mm; P <.0001). Conclusion: Age represented a relevant risk factor for impaired skeletal microarchitecture in the proximal fibula in women but not men. The region of drill tunnels according to anatomic techniques showed superior bone microarchitecture versus that according to the Larson technique. [ABSTRACT FROM AUTHOR]

The tibial joint line is offset posteriorly relative to the tibial sagittal anatomic axis. This can have consequences when using stemmed implants during total knee arthroplasty. We retrospectively analyzed native knee lateral radiographs in 100 patients. The distance between the sagittal anatomic axis and the center of a simulated tibial resection was calculated as a percentage of overall tibial width. Analysis of 5 manufacturers’ baseplates showed that the tibial stem attached on average 10% anterior to the midline. We measured the impingement point of a 12-mm-diameter stem starting from this position. The tibial joint surface was offset posteriorly from the anatomic axis in all patients by an average of 23.5% of the tibial width (range: 13.1%-33.2%). A 12-mm tibial stem would impinge within 40 mm in 2% (2/100) of patients and within 60 mm in 19% (19/100). There was a weak but statistically significant correlation between proximal tibial offset and distance to impingement. During total knee arthroplasty, the center of the cut tibia is offset posteriorly from the sagittal anatomic axis. In patients with high offset, tibial stem extensions can impinge against the posterior tibia, causing baseplate malpositioning, diminished cement mantle, or fracture.

Context: Modifiable and nonmodifiable risk factors have been identified for sustaining a primary anterior cruciate ligament (ACL) injury; however, less research is available examining risk factors for a second injury. Identifying whether bony morphological factors are different (or more exaggerated) among those that experience a secondary ACL injury is critical to understanding if nonmodifiable risk factors are associated with a second injury. Objective: To determine if bony morphology is different among those that experience a secondary ACL reinjury as compared with those that do not. Design: Case-control. Setting: University laboratory. Participants and Interventions: ACL participants were tracked after return to play following primary reconstruction, and if individuals experienced a second ipsilateral injury (ACLx2; n = 14, 8f/6m, 17.9 ± 4.0 y), the primary clinical MRI was analyzed for bony morphological risk factors. ACLx2 participants were matched to individuals (sex, age, height, graft, gender, and activity level) that had undergone reconstruction but did not experience reinjury (ACLx1, n = 14, 8f/6m, 18.7 ± 4.0 y). Ten controls were also enrolled (5m/5f, 20.8 ±3.9 y) for the purposes of comparing the authors' ACL data against healthy knees. Main Outcome Measures: Lateral and medial posterior tibial slopes (LPTS, MPTS), notch shape index (NSI), and medial tibial plateau depth of concavity (MDC). Results: All ACL-reconstructed patients (combined ACLx1 and ACLx2 group) had a steeper LPTS than controls (d = 0.87, 95% CI 0.11-1.60, P = .023); however, no difference in LPTS was found between ACLx1 and ACLx2 (P > .05). No differences in MPTS, NSI, and MDC were found between all ACL participants (combined ACLx2 and ACLx1) and controls or between ACLx1 and ACLx2 (P > .05). Conclusions: Compared to healthy individuals, a steeper LPTS is a common bony abnormality in all ACL-injured participants. Individuals that go on to experience a second ipsilateral ACL injury do not have more exaggerated bony morphology than those that do not suggesting that differences in modifiable risk factors at return to play may contribute to reinjury. [ABSTRACT FROM AUTHOR]

Background: Coronal alignment after total knee arthroplasty (TKA) would influence the implant survival. Coronal alignment could be measured on short and full-length X-rays. The goal of the current study was to assess the correlation of short and full-length X-rays to accurate prediction of the true Hip-Knee-Ankle alignment after TKA in the Iranian population. Methods: Lateral distal femoral and medial proximal tibial angles, FTA, HKA, in 180 Iranian patients (243 knees without extra-articular deformities) were measured and compared on short and full-length standing X-rays of primary TKA pre/postoperatively. Results: The correlation between the preoperative FTA-short and FTA-long, FTA-short and HKA, and FTA-long and HKA values in degrees were fair, good and good (r = 0.64) (r = 0.73), (r = 0.76), respectively. This correlation for postoperative aMPTA and mMPTA (r = 0.73), and FTA-short and HKA (r = 0.76) values were good and significant (P = 0.001). Also, assessing coronal alignment based on short and full-length measurements would result in varying pre/postoperative alignments (varus, neutral and valgus). Conclusion: Full length X-rays could not be replaced by short knee X-rays to asses true coronal alignment in TKA; considerable portion of our cases were missorted as varus, neutral or valgus based on the FTA versus the HKA. Intraoperative fixed 5° valgus angle cut of distal femur did not result in postoperative favorable neutral alignment in all cases. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Background: Determining the rotational axis of the bony trough during lateral meniscal allograft transplant (MAT) is difficult. The use of anatomic landmarks may help a surgeon determine the rotational alignment of the graft during the procedure. Purpose: To investigate the association between the knee's anatomic landmarks and the position of the bony trough to prevent extrusion after lateral MAT. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Enrolled were 44 patients who underwent lateral MAT between July 2000 and February 2011. The patients' mean age at the time of surgery was 30.8 years. Extrusion was measured on magnetic resonance imaging (MRI) scans at a mean of 3.6 months postoperatively, and patients were divided into an extrusion group (n = 15) and a no-extrusion group (n = 29). Three coronal MRI scans from each patient were selected, each from the region at the level of the tibial tuberosity (TT), the anterior bony trough, and the posterior bony trough. We measured the distance between the center of the anterior bony trough and the center of the TT (the TT distance) and the distance between the center of the posterior bony trough and the medial border of the lateral femoral condyle (LFC) (the LFC distance). Results: The mean center of the anterior bony trough was in a more medial position relative to the center of the TT in the no-extrusion group (–2.9 ± 4.8 mm) compared with the extrusion group (1.3 ± 4.9 mm; P =.010). The mean center of the posterior bony trough was in a more medial position relative to the medial border of the LFC in the no-extrusion group (–1.7 ± 3.9 mm) compared with the extrusion group (1.0 ± 3.2 mm; P =.027). Both TT distance and LFC distance were significantly correlated with extrusion (P =.005 and.025, respectively). The cutoff value was –0.24 mm for the anterior bony trough and –0.58 mm for the posterior bony trough (negative values indicate that the trough was medial to the respective landmarks). Conclusion: To prevent extrusion of the allograft, the center of the anterior bony trough needs to be aligned with the center of the TT, and the center of the posterior bony trough needs to be aligned with the medial border of the LFC. [ABSTRACT FROM AUTHOR]

Background: The medial patellofemoral complex (MPFC) is a structure composed of the medial quadriceps tendon–femoral ligament (MQTFL) superiorly and the medial patellofemoral ligament (MPFL) inferiorly. The pediatric MPFL anatomy has been well described, but the precise anatomy of the MQTFL has only recently been described and studied in skeletally immature patients. Purpose: To describe the anatomic relationship between the MQTFL and its insertion on the quadriceps tendon and patella in pediatric specimens. Study Design: Descriptive laboratory study. Methods: A total of 22 pediatric cadaveric knee specimens were dissected to analyze attachment of the MQTFL to the quadriceps tendon and patella. Dissection was facilitated using lateral parapatellar arthrotomy followed by eversion of the extensor mechanism to evaluate MQTFL fibers from its undersurface. Results: The mean specimen age was 7.4 years. Specimens were divided based on age into a younger cohort (1-2 years), middle cohort (4-8 years), and older cohort (9-12 years). The quadriceps tendon attachment (QTA) of the MQTFL proximal to the patella extended a median of 5.0 mm in the younger cohort, 11.4 mm in the middle cohort, and 12.0 mm in the older cohort, with significant differences found between the younger and middle cohorts (P <.047) and the younger and older cohorts (P <.001). The QTA as a percentage of patellar articular height averaged 44.4% across all specimens. The vertical height of the patella measured a median of 14.0 mm, 22.3 mm, and 27.3 mm in the younger, middle, and older cohorts, respectively. Conclusion: This study expands on the recently described anatomy of the pediatric MPFC to quantify the anatomic relationship between the MQTFL attachment to the quadriceps tendon and patella in a more clinically relevant cohort of donor specimens. Clinical Relevance: As access to pediatric cadaveric tissue is extremely limited, a better understanding of MPFC and MQTFL anatomy will support surgeons in preoperative planning and intraoperative considerations for their approach to MQTFL and MPFL reconstruction. This may facilitate improved anatomic surgical stabilization of the patellofemoral joint in pediatric patients. [ABSTRACT FROM AUTHOR]

Objective. Knee osteoarthritis (KOA) remains a challenge for clinicians worldwide and lacks major advancements in treatment. In this study, we investigated the mechanism of synovitis ointment interference on KOA. Methods. SD rats were used to establish KOA models and were randomly divided into five groups: the control group, the KOA group, the KOA + synovitis ointment group, the KOA + Western medicine group, and the KOA + Chinese medicine group. Detection of pathological injury of the joint was observed through HE staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure the expression of SDF-1, CXCR4, MMP-9, and MMP-13. Effects of synovitis ointment on bone cell fibrosis were detected through Masson staining, and the relative mRNA expression of PLOD2, COL1A1, TIMP1, and TGF-β was observed using the real-time quantitative (RT-PCR) method. Results. Mankin's score and the knee diameters showed that the KOA model has been successfully established; compared with the OA group, the synovitis ointment group improved the pathological injury of the knee joint. Compared with the KOA group, the synovitis ointment group, the KOA + Western medicine group, and the KOA + Chinese medicine group significantly decreased the expression of SDF-1, CXCR4, MMP-9, and MMP-13. Synovitis ointment reduced the relative content of bone cell fiber compared to that in the KOA group. While, the relative mRNA expression of PLOD2, COL1A1, TIMP1, and TGF-β was significantly decreased in the synovitis ointment group. Conclusion. Synovitis ointment inhibited the inflammation and bone cell fibrosis of KOA, and the mechanism was related to the SDF-1/CXCR4 singling pathway. [ABSTRACT FROM AUTHOR]

Introduction: In the last decade, fascia research increased significantly in various aspects such as anatomical and biomechanical features related to epimuscular force transmission. Methods: The present anatomic study focuses on macroscopic observations of the potential gracilis and semitendinosus paratenons, as well as fascial surroundings connections in the posteromedial knee region on 17 lower-limbs dissections. Results: The gracilis and semitendinosus expansions and paratenons were observed in all specimen and further connections with the fascia lata and crural fascia were demonstrated. Contrary to the previously described expansions connected to the tendons, we observed that the expansions were the edges of the paratenon tunnel and that the paratenon structure surrounded the overall muscle. Both paratenons of gracilis and semitendinosus were connected to the crural fascia and, respectively, to the sartorius fascia (part of the fascia lata), to the semimembranosus and the fascia lata. Furthermore, numerous connections between the fascia lata and the neighboring structures in the posteromedial knee region are described. Discussion–conclusion: The present study describes for the first time gracilis and semitendinosus paratenons and other surrounding fascial connections. Such macroscopic observations may represent a new basis for further characterization of the myofascial pathway of epimuscular force transmission in the knee region. [ABSTRACT FROM AUTHOR]

Background: The contribution of anterior cruciate ligament (ACL) injury to lateral instability under varus stress, particularly compared with posterolateral structures, is not well known. Purpose: To investigate the effect of sectioning the ACL and posterolateral knee structures on lateral compartment gapping under varus stress. Study Design: Controlled laboratory study. Methods: Fourteen nonpaired cadaveric knees were randomized to 1 of 2 groups: sequential sectioning of the ACL, fibular collateral ligament (FCL), popliteus tendon (PLT), and popliteofibular ligament (PFL) (ACL-first group) or sequential sectioning of the FCL, PLT, PFL, and ACL (FCL-first group). Knees were loaded onto a custom jig at a 20° flexion angle. A standardized 12-N·m varus moment was applied to each specimen in the intact state and after each randomized sequential-sectioning state. Lateral compartment opening was measured on radiographs to assess the contribution to the increase in the lateral gap caused by resecting the respective structure. The distance was measured by 3 observers on 15 images (5 testing states each imaged 3 times) per specimen, for a total of 210 radiographs. The articular cartilage surfaces were not included in the measurements. Results: The mean increase in lateral opening after sectioning all structures (ACL and posterolateral corner) was 4.6 ± 1.8 mm (range, 1.9-7.7 mm). The ACL and FCL sectioning contributed the most to lateral knee opening (1.3 ± 0.6 and 2.2 ± 1.3 mm, respectively). In both groups, lateral gapping >3 mm was achieved only after both the ACL and FCL were sectioned. All comparisons of increased mean gapping distances demonstrated a significant difference with subsequent sequential sectioning of structures, except comparisons between the FCL and PLT and the PLT and PFL. When considering the effect of the ACL on lateral opening, no significant difference was found between sectioning the ACL first or FCL first (P =.387). Conclusion: ACL deficiency significantly increased lateral opening under varus stress, regardless of the sequence of injury. The effect of injury to the ACL in addition to the lateral structures should be considered when using varus stress radiographs to evaluate knee injuries. Clinical Relevance: With the current findings, understanding the effect of ACL and posterolateral corner injuries on lateral gapping under varus stress can aid in correctly diagnosing knee injuries and determining appropriate treatment plans. [ABSTRACT FROM AUTHOR]