This study of collegiate basketball players evaluated change over time (COT) in ultrasound shear wave (SW) elastography metrics across the basketball season, and correlated to morphologic changes on conventional ultrasound imaging, and VISA-P scores. In eleven male collegiate basketball players (mean age 19, age range 18–21), patella tendon (PT) ultrasound and SW elastography of both knees were performed at pre-season and post-season time points, and players reported their VISA-P scores throughout the season. Patella tendinopathy grade and SW metrics were correlated to VISA-P scores using Spearman correlation coefficients. Paired t-test was used to assess differences in mean SW metrics at pre-and post-season timepoints, accounting for leg dominance. 6 of 11 players (54.5%) had baseline patella tendinopathy on ultrasound progressing in 4 players. The mean change in VISA-P score was 15.18 (+/−8.55). No significant correlation was seen between ultrasound grades of tendinopathy and VISA-P. Pre-season SW velocities did not significantly correlate with baseline VISA-P scores. Post-season SW values and SW COT demonstrated strong correlation with change in VISA-P score in dominant and non-dominant knees. Although not statistically significant, there was a trend towards higher SW velocity for tendinopathy in both dominant and non-dominant knees at both study visits. SW metrics of the PT correlated to change in VISA-P scores in the dominant and non-dominant knees, whereas conventional ultrasound grades of patella tendinopathy did not. There was a trend towards higher SW velocities in patella tendinopathy which may indicate detection of change in intrinsic tissue stiffness

Posterior cruciate ligament deficiency (PCLD) leads to structural and proprioceptive impairments of the knee, affecting the performance of daily activities including obstacle-crossing. Therefore, identifying the biomechanical deficits and/or strategies during this motor task would be helpful for rehabilitative and clinical management of such patients. A safe and successful obstacle-crossing requires stability of the body and sufficient foot clearance of the swing limb. Patients with PCLD may face demands different from normal when negotiating obstacles of different heights. The objective of this study was thus to identify the biomechanical deviations/strategies of the lower limbs in unilateral PCLD during obstacle-crossing using motion analysis techniques. Twelve patients with unilateral PCLD and twelve healthy controls participated in the current study with informed written consent. They were asked to walk and cross obstacles of heights of 10%, 20% and 30% of their leg lengths at self-selected speeds. The PCLD group was asked to cross the obstacles with each of the affected and unaffected limb as the leading limb, denoted as PCLD-A and PCLD-U, respectively. The kinematic and kinetic data were measured with a 7-camera motion analysis system (Vicon, Oxford Metrics, U.K.) and two force plates (AMTI, U.S.A.). The angles of the stance and swing limbs (crossing angles) and the moments of the stance limbs (crossing moments) for each joint in the sagittal plane when the leading limb was above the obstacle were calculated for statistical analysis. A 3 by 2, 2-way mixed-model analysis of variance with one between-subject factor (PCLD-A vs. Control, and PCLD-U vs. Control) and one within-subject factor (obstacle height) was performed (α=0.05). Paired t-test was used to compare the variables between PCLD-A and PCLD-U (α=0.05). SAS version 9.2 was used for all statistical analysis. When the leading toe was above the obstacle, the PCLD group showed significantly greater hip flexion in the swing limb but decreased dorsiflexion in the stance limb, both in PCLD-A and PCLD-U (P<0.05). Greater knee flexion and greater ankle dorsiflexion were found in the leading limb in PCLD-A (P<0.05). Meanwhile, the PCLD group showed significantly decreased ankle plantarflexor but increased knee extensor crossing moments in the stance limb compared with the Control (P<0.05). None of the calculated variables were found to be significantly different between PCLD-A and PCLD-U (P>0.05). When crossing the obstacle, patients with PCLD reduced ankle plantarflexor moments that were mainly produced by the gastrocnemius. This may help reduce the posterior instability of the affected knee. Greater knee extensor crossing moments may also help reduce the posterior instability of the standing knee when the leading toe was above the obstacle. The changed joint kinetics as a result of PCLD were not only seen on the affected side but also on the unaffected side during obstacle-crossing. This symmetrical pattern may be necessary in performing functional activities that may require either the affected side or the unaffected side leading. These results suggest that rehabilitative intervention, including muscular strengthening, on both affected and unaffected sides are necessary in patients with unilateral PCLD

Abstract. Objective. Explore whether high tibial osteotomy (HTO) changes knee contact forces and to explore the relationship between the external knee adduction moment (EKAM) pre and 12 months post HTO. Methods. Three-dimensional gait analysis was performed on 17 patients pre and 12-months post HTO using a modified Cleveland marker-set. Tibiofemoral contact forces were calculated in SIMM. The scaled musculoskeletal model integrated an extended knee model allowing for 6 degrees of freedom in the tibiofemoral and patellofemoral joint. Joint angles were calculated using inverse kinematics then muscle and contact forces and secondary knee kinematics were estimated using the COMAC algorithm. Paired samples t-test were performed using SPSS version 25 (SPSS Inc., USA). Testing for normality was undertaken with Shapiro-Wilk. Pearson correlations established the relationships between EKAM1 to medial KCF1, and EKAM2 to medial KCF2, pre and post HTO. Results. Total knee contact force peak 1 significantly reduced from 2.6 x body weight pre-HTO to 2.3 x body weight 12-months post-HTO. Medial contact force peak 1 significantly reduced from 1.7 x body weight pre-HTO to 1.5 x body weight 12-months post-HTO. Second peak lateral knee contact force significantly increased from 0.9 body weight pre-HTO to 1.1 x body weight 12-months post-HTO. Furthermore, this study found very strong correlations between EKAM1 and medial KCF1 pre-HTO (r=0.85) as well as post-HTO (r=0.91). There was a significantly moderate relationship between EKAM2 and medial KCF2 pre-HTO (r=0.625). Conclusion. HTO significantly reduced overall and medial KCF during the first half of stance whilst increasing second half of stance peak lateral knee contact force. This study demonstrated a strong relationship between EKAM peaks and respective medial KCF peaks, supporting the usefulness of EKAM as a surrogate measure of medial compartment tibiofemoral contact forces. This demonstrates HTO successfully offloads the tibiofemoral joint overall, as well as offloading the medial compartment