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Objectives: Medial meniscus posterior root (MMPR) tears can result in rapidly progressing osteoarthritis if left untreated. Prior research has demonstrated that MMPR tears are frequently preceded by medial meniscotibial ligament (MTL) disruption and medial meniscus extrusion. Although meniscus extrusion is a physiologic phenomenon observed after sustained activity, the impact of excessive medial meniscus extrusion resulting from MTL disruption on forces experienced at the MMPR remains uncertain. Moreover, repairing MMPR tears does not always correct medial meniscus extrusion, suggesting that MTL repair or tenodesis may provide some benefit as a concomitant procedure to MMPR repair in terms of restoring native forces. The aim of this study was to assess the relationship between medial meniscus extrusion and MMPR forces in the setting of MTL insufficiency and following MTL tenodesis while subjecting the joint to progressive cyclic loading. We hypothesized that 1) medial meniscus extrusion resulting from MTL insufficiency would increase MMPR forces; 2) MMPR forces and extrusion would both increase as the number of loading cycles increased; and 3) MTL tenodesis would decrease medial meniscus extrusion and restore MMPR forces to native levels. Methods: Fifteen pairs of fresh-frozen, cadaveric human knees were organized in a balanced incomplete block design (BIBD) consisting of three testing groups: a native group, a group in which the MTL was disrupted (MTL Cut), and a group in which the MTL was disrupted and then repaired via a peripheral centralization procedure using two knotless all-suture anchors (MTL Tenodesis). Specimens were dissected down to the knee capsule, and the femur/tibia bones were potted. A three-axis force sensor was installed inferior to the MMPR such that forces acting on the MMPR could be measured across three axes. Specimens were then mounted in full extension to a dynamic materials testing machine (Fig. 1), and baseline meniscus extrusion and three-dimensional (3D) force measurements were captured. 3D MMPR forces were measured from the force sensor, and ultrasound (US) was used to image the medial meniscus. Each specimen was subjected to compressive cyclic loading over 10,000 cycles at a 1 Hz frequency ranging from 500 N to 20 N. After the 0th cycle, 100th cycle, 1,000th cycle, and 10,000th cycle, a 500 N load was applied, the medial meniscus was imaged, and 3D forces were measured. Medial meniscus extrusion was measured from the resulting US images. To date, means and standard deviations have been calculated for 11 cadaveric pairs, and Pearson correlations were calculated between outcomes. The full data set will be analyzed with an analysis of variance method corresponding to the BIBD. Pairwise group comparisons will be made among the estimated marginal means (Tukey's method). Results: Eleven pairs of specimens have been tested as of this submission: 6 native, 8 MTL Cut, and 8 MTL Tenodesis. For all states, medial meniscus extrusion increased as the number of loading cycles increased. The MTL Cut state demonstrated increased meniscus extrusion relative to the native state, and MTL tenodesis restored extrusion back to the native level (Fig. 2). In all states, MMPR medial shear force and compression decreased as the number of cycles increased. MMPR medial shear force and compression increased to a greater extent in the MTL Cut state compared to the native state, and MTL tenodesis did not restore shear nor compression forces to native levels (Fig. 3 and Fig. 4). Meniscus extrusion was weakly correlated to MMPR medial shear at lower numbers of cycles (0th: R = 0.2, 100th: R = 0.5) and strongly correlated to MMPR medial shear at higher numbers of cycles (1,000th: R = 0.93, p < 0.001; 10,000th: R = 0.82, p = 0.002). Conclusions: As hypothesized, medial meniscus extrusion, MMPR medial shear force, and MMPR compression were higher in the MTL Cut state compared to the native state. While the MTL tenodesis reduced medial meniscus extrusion to the native level, MMPR forces were not restored to native levels. Also in line with our hypothesis, meniscus extrusion increased with progressive loading. Interestingly, MMPR medial shear force decreased with progressive loading cycles, and the Pearson correlation between meniscus extrusion and MMPR medial shear force was stronger at higher levels of cyclic loading. Based on these findings, MTL tenodesis should be considered as an effective treatment option for reducing medial meniscus extrusion both in patients with isolated MTL insufficiency and in the setting of MMPR tears with medial meniscus extrusion. Further research is necessary to determine how the various MTL repair and tenodesis techniques affect MMPR forces. The observed correlation between meniscus extrusion and MMPR medial shear force provides an interesting insight into native meniscal function. As the knee joint undergoes repetitive loading, the medial meniscus undergoes physiologic extrusion, which decreases MMPR medial shear force and may thereby protect the MMPR. Conversely, the MMPR may be at increased risk for injury when the knee undergoes acute loading, and the medial meniscus does not have the opportunity to undergo physiologic extrusion or in the setting of excessive medial meniscus extrusion resulting from MTL insufficiency. This finding also experimentally supports the theoretical assertion that the meniscus, anchored by the roots, transmits femoral compressive loads into circumferential loads. [ABSTRACT FROM AUTHOR]

Objectives: Preoperative tibial and femoral osteotomy planning using three-dimensional (3D) patient-specific instrumentation (PSIs) has been gaining popularity in deformity correction surgery. However, the variability between advanced imaging modalities and conventional two-dimensional (2D) radiographs for measuring limb alignment and corrective osteotomy angle remains unknown. Though CT is generally considered the gold standard for osseous imaging, radiographs remain the most common means for assessing preoperative coronal and sagittal alignment. Emerging data suggest there may be inaccuracies with this technique. In particular, multiple studies have found that sagittal slope measurements can vary greatly depending on modality used. The present study aims to characterize alignment measurements within a cohort of patients undergoing corrective osteotomy and to assess differences in preoperative planned alignment and correction angles between an advanced 3D imaging modality (Bodycad, Quebec, CA) and conventional 2D radiographs. Methods: Preoperative computed tomography (CT) scans of consecutive patients undergoing high tibial osteotomies (HTOs) and/or distal femoral osteotomies (DFOs) between January 1st, 2016, and December 1st, 2022 with preoperative x-ray and CT scans were retrospectively reviewed using advanced 3D PSI software. Equivalent 2D radiographs were independently analyzed using conventional imaging software. Manual 2D radiograph measurements, including hip-to-ankle weightbearing axis and posterior tibial slope were compared to 3D PSI measurements and variances were analyzed calculating Root Mean Square Error (RMSE). Results: A total of 97 patients (47 female, 50 males) with a mean age of 37 years (range, 15.8 to 60 years) were included in the final analysis. Fifty percent of the cohort had a lateral posterior tibial slope (LPTS) that was greater than medial posterior tibial slope (MPTS). Mean absolute posterior slope difference (aPTSD) did not vary significantly according to osteotomy type. For manual measurements, interclass correlation coefficients among raters was excellent (0.97, 95% CI 0.944, 0.988) in the coronal plane, while interclass correlation coefficient for the sagittal plane was poor. Mean hip-to-ankle corrective angle using conventional 2D radiographs was 6.02° (range, 0.45° to 19.62°), versus 7.31° on Bodycad (range, 3.25° to 10.63°) (p=0.022). Conclusions: Preoperative corrective osteotomy angles between advanced imaging software and conventional radiographs measurements are significantly different, with 3D CT predicting a significantly higher overall correction angle for all parameters. Despite excellent interrater reliability for coronal plane measurements using radiographs, reliability for slope measurements was poor. Surgeons should be mindful when using conventional 2D radiographs for osteotomy planning, which may underestimate correction angles and inaccurately assess preoperative sagittal alignment. [ABSTRACT FROM AUTHOR]

The article presents a study on topic of “Factors Predictive of Concomitant Injuries Among Children and Adolescents Undergoing Anterior Cruciate Ligament Surgery" done by Justin T. Newman and colleagues at Children's Hospital Colorado, Aurora, Colorado, USA. The article mentions methods, statistical analysis and results. The findings show that the prevalence of concomitant knee injuries as well as the need for additional operative procedures was greater among older subjects when compared with younger subjects.

The article discusses a study which aimed to identify factors associated with anterior cruciate ligament (ACL) graft failure in an adolescent cohort. Results show that autograft failure tend to remain constant 24 to 48 months after initial surgery, while allograft failure risk continued to increase during postoperative months 24 to 48. It concluded that graft type and postoperative knee laxity are significant predictors of graft survival.

Background: Anterior tibial spine fractures (ATSF) in the skeletally immature parallel anterior cruciate ligament (ACL) tears in adult patients, yet these injuries are generally regarded as mutually exclusive. Biomechanical analysis suggests that intrinsic ACL damage occurs during ATSF, and long-term clinical studies demonstrate residual anteroposterior knee laxity following ATSF. We aim to describe prevalence, demographics, and characteristics of pediatric patients who sustained ATSF with concomitant ACL injury., Methods: We included 129 patients with ATSF over a 16-year period. Age, sex, injury mechanism, ATSF type, magnetic resonance imaging (MRI) evaluation, treatment modality, ACL injury, and concomitant meniscal/chondral injuries were analyzed. Concurrent ACL injury was confirmed either from MRI or intraoperatively., Results: Nineteen percent (n=25) of ATSF patients had concomitant ACL injury, with ACL injury significantly more likely in type II or type III ATSF compared with type I ATSF (P=0.03). Patients with combined ATSF/ACL injury were significantly older (P=0.02) and more likely to be male (P=0.01). Mechanism of ATSF injury was not associated with ACL injury (P=0.83). Preoperative MRI had low sensitivity (0.09) for recognizing ACL injury at the time of ATSF relative to intraoperative assessment. Half of ATSF/ACL-injured patients had additional meniscal or chondral injury, with meniscal repair or debridement required in 37.5% of the type II ATSF/ACL injury., Conclusions: There are demographic characteristics, such as age (older) and sex (male), associated with a higher risk of concomitant ACL injury at the time of ATSF. Type II and type III ATSF patterns had a higher prevalence of ACL injury. MRI failed to correctly identify ACL injury at the time of ATSF. Concomitant ACL injury at the time of ATSF is highly prevalent in the skeletally immature, occurring in 19.4% of patients with ATSF., Level of Evidence: Level IV-case series.

Background: Historically, bicycle accidents were described as the most common mechanism for pediatric anterior tibial spine fractures (ATSFs). There is a paucity of current literature examining the demographic factors associated with these injuries. The purpose of this cohort study was to characterize the epidemiology of ATSFs presenting to a single tertiary referral pediatric hospital., Methods: A consecutive cohort of 122 pediatric patients with ATSFs between 1996 and 2014 were reviewed. Radiographic variables, classification of fractures (Meyers and McKeever type), age, sex, height, weight, body mass index, and mechanism of injury were retrieved. Categories of mechanism of injury included organized sports (football, soccer, basketball, lacrosse, wrestling, and gymnastics), bicycling, outdoor sports (skiing, skateboarding, and sledding), fall, motor vehicle collision/pedestrian versus motor vehicle, and trampoline., Results: Organized sports-related injuries represented the most common cause of ATSFs (36%). Other common mechanisms of injury included bicycle accidents (25%), outdoor sports (18%), and falls (11%). There was a higher proportion of males (69%) compared with females (31%). Males (mean age, 11.6 y) were significantly older than females (mean age, 9.8 y) (P=0.004). Younger patients (aged 11.5 y and below) were more likely to have displaced fractures (type III), whereas type I and type II were more common in patients above 11.5 years (P=0.02). Patients with fracture type I were significantly taller than patients with fracture type III. No other variables were found to differ significantly according to fracture severity, including sex, weight, and body mass index., Conclusions: To our knowledge, our study represents both the largest (n=122) and most up-to-date epidemiological ATSF study in pediatric patients. A higher rate of ATSF occurs due to organized sports rather than bicycling or motor vehicle collision. This 18-year data collection represents a change in the paradigm, and is likely multifactorial, including increased participation in youth sports and early sport specialization., Level of Evidence: Level IV-retrospective, cohort study.