Laura E. Stanley

Sex Differences in the Incidence of Anterior Cruciate Ligament, Medial Collateral Ligament, and Meniscal Injuries in Collegiate and High School Sports 2009-2010 Through 2013-2014

Background: Previous research has noted sex-based differences in anterior cruciate ligament (ACL) injury rates in young athletes, while little is known about medial collateral ligament (MCL) and meniscal injury rates in this population. The objective of this study was to compare injury rates for traumatic knee injuries (ie, ACL, MCL, and meniscal injuries) in collegiate and high school (HS) varsity student-athletes across multiple sports. Hypothesis: Knee injury rates vary by sex and across different sports and levels of competition. Study Design: Descriptive epidemiology study. Methods: Injury and athlete-exposure data were utilized from the National Athletic Treatment, Injury and Outcomes Network (NATION) and National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009-2010 to 2013-2014 academic years. Analyses focused on ACL, MCL, and meniscal injuries. Injury rates and injury rate ratios (IRRs) with 95% CIs were calculated for basketball, ice hockey, lacrosse, soccer, and baseball/softball. Results: The ACL injury rate was higher for female than male athletes at the collegiate (IRR, 2.49; 95% CI, 1.81-3.41) and HS (IRR, 2.30; 95% CI, 1.67-3.18) levels. At the collegiate level, the highest ACL IRR comparing female to male athletes was reported in softball/baseball (IRR, 6.61; 95% CI, 1.48-29.55). At the HS level, the highest ACL IRR was reported in basketball (IRR, 3.68; 95% CI, 1.91-7.10). The MCL injury rate was higher for female than male athletes at the HS level (IRR, 2.11; 95% CI, 1.25-3.56) but lower for female than male athletes at the collegiate level (IRR, 0.73; 95% CI, 0.59-0.92). The meniscal injury rate was lower for female than male athletes at the HS level (IRR, 0.47; 95% CI, 0.31-0.71), while no differences by sex were seen at the collegiate level (IRR, 1.35; 95% CI, 0.90-2.02). Conclusion: Knee injury rates varied by sex across 5 different sports in the HS and collegiate settings. Female athletes sustained ACL injuries at a higher rate than male athletes at both the HS and collegiate levels in these 5 sports; however, there was not a distinct sex disparity in MCL and meniscal injuries. Future studies should examine the rates of concomitant and recurrent injuries to inform injury prevention and rehabilitation programs.

Biochemical markers of cartilage metabolism are associated with walking biomechanics 6-months following anterior cruciate ligament reconstruction: Biomechanics and Biomarkers Post ACLR

The purpose of our study was to determine the association between biomechanical outcomes of walking gait (peak vertical ground reaction force [vGRF], vGRF loading rate [vGRF‐LR], and knee adduction moment [KAM]) 6 months following anterior cruciate ligament reconstruction (ACLR) and biochemical markers of serum type‐II collagen turnover (collagen type‐II cleavage product to collagen type‐II C‐propeptide [C2C:CPII]), plasma degenerative enzymes (matrix metalloproteinase‐3 [MMP‐3]), and a pro‐inflammatory cytokine (interleukin‐6 [IL‐6]). Biochemical markers were evaluated within the first 2 weeks (6.5 ± 3.8 days) following ACL injury and again 6 months following ACLR in eighteen participants. All peak biomechanical outcomes were extracted from the first 50% of the stance phase of walking gait during a 6‐month follow‐up exam. Limb symmetry indices (LSI) were used to normalize the biomechanical outcomes in the ACLR limb to that of the contralateral limb (ACLR/contralateral). Bivariate correlations were used to assess associations between biomechanical and biochemical outcomes. Greater plasma MMP‐3 concentrations after ACL injury and at the 6‐month follow‐up exam were associated with lesser KAM LSI. Lesser KAM was associated with greater plasma IL‐6 at the 6‐month follow‐up exam. Similarly, lesser vGRF‐LR LSI was associated with greater plasma MMP‐3 concentrations at the 6‐month follow‐up exam. Lesser peak vGRF LSI was associated with higher C2C:CPII after ACL injury, yet this association was not significant after accounting for walking speed. Therefore, lesser biomechanical loading in the ACLR limb, compared to the contralateral limb, 6 months following ACLR may be related to deleterious joint tissue metabolism that could influence future cartilage breakdown.

Sagittal plane kinematics predict kinetics during walking gait in individuals with anterior cruciate ligament reconstruction

BACKGROUND Alterations in mechanical loading following anterior cruciate ligament reconstruction may lead to the development of knee osteoarthritis. Feedback that cues a change in knee kinematics during walking gait may influence mechanical loading, yet it remains unknown if knee kinematics predict kinetics during walking gait. Our aim was to determine if sagittal plane knee kinematics predict kinetics during walking gait in anterior cruciate ligament reconstructed individuals. METHODS Forty-one individuals with a history of primary, unilateral anterior cruciate ligament reconstruction completed a motion capture walking gait analysis. Hierarchical linear regression analyses were used in order to determine the amount of variance in the kinetic variables of interest (peak vertical ground reaction force, instantaneous and linear vertical ground reaction force loading rate) that was individually predicted by the kinematic variables of interest (knee flexion angle at heelstrike, peak knee flexion angle, and knee flexion excursion). FINDINGS Knee flexion excursion of the injured limb significantly predicted 11% of the variance in peak vGRF of the injured limb after accounting for gait speed and peak knee flexion angle (ΔR2=0.11, P=0.004). After accounting for gait speed and knee flexion angle at heelstrike, knee flexion excursion significantly predicted 16% of the variance in the injured limb peak vertical ground reaction force (ΔR2=0.16, P=0.001). No kinematic variable predicted vertical ground reaction force loading rate. INTERPRETATION Altering knee flexion excursion may be useful as a future therapeutic target for modifying peak vertical ground reaction force during walking gait following anterior cruciate ligament reconstruction.

Associations Between Slower Walking Speed and T1ρ Magnetic Resonance Imaging of Femoral Cartilage Following Anterior Cruciate Ligament Reconstruction

To determine whether walking speed, collected at 6 and 12 months following anterior cruciate ligament reconstruction (ACLR), is associated with inter‐extremity differences in proteoglycan density, measured via T1ρ magnetic resonance imaging, in tibiofemoral articular cartilage 12 months following ACLR.

Peak knee biomechanics and limb symmetry following unilateral anterior cruciate ligament reconstruction: Associations of walking gait and jump-landing outcomes

Background Aberrant walking‐gait and jump‐landing biomechanics may influence the development of post‐traumatic osteoarthritis and increase the risk of a second anterior cruciate ligament injury, respectively. It remains unknown if individuals who demonstrate altered walking‐gait biomechanics demonstrate similar altered biomechanics during jump‐landing. Our aim was to determine associations in peak knee biomechanics and limb‐symmetry indices between walking‐gait and jump‐landing tasks in individuals with a unilateral anterior cruciate ligament reconstruction. Methods Thirty‐five individuals (74% women, 22.1 [3.4] years old, 25 [3.89] kg/m2) with an anterior cruciate ligament reconstruction performed 5‐trials of self‐selected walking‐gait and jump‐landing. Peak kinetics and kinematics were extracted from the first 50% of stance phase during walking‐gait and first 100 ms following ground contact for jump‐landing. Pearson product‐moment (r) and Spearmans Rho (&rgr;) analyses were used to evaluate relationships between outcome measures. Significance was set a priori (P ≤ 0.05). Findings All associations between walking‐gait and jump‐landing for the involved limb, along with the majority of associations for limb‐symmetry indices and the uninvolved limb, were negligible and non‐statistically significant. There were weak significant associations for instantaneous loading rate (&rgr; = 0.39, P = 0.02) and peak knee abduction angle (&rgr; = 0.36, p = 0.03) uninvolved limb, as well as peak abduction displacement limb‐symmetry indices (&rgr;= − 0.39, p = 0.02) between walking‐gait and jump‐landing. Interpretation No systematic associations were found between walking‐gait and jump‐landing biomechanics for either limb or limb‐symmetry indices in people with unilateral anterior cruciate ligament reconstruction. Individuals with an anterior cruciate ligament reconstruction who demonstrate high‐involved limb loading or asymmetries during jump‐landing may not demonstrate similar biomechanics during walking‐gait. HighlightsAltered kinetics and kinematics observed following anterior cruciate ligament reconstruction may be task dependent.Individuals with greater peak biomechanics during walking do not demonstrate greater peak biomechanics during jump‐landing.Asymmetrical walking does not correlate with asymmetrical jump‐landing following anterior cruciate ligament reconstruction.

Automated Quantification of the Landing Error Scoring System With a Markerless Motion-Capture System

CONTEXT   The Landing Error Scoring System (LESS) can be used to identify individuals with an elevated risk of lower extremity injury. The limitation of the LESS is that raters identify movement errors from video replay, which is time-consuming and, therefore, may limit its use by clinicians. A markerless motion-capture system may be capable of automating LESS scoring, thereby removing this obstacle. OBJECTIVE   To determine the reliability of an automated markerless motion-capture system for scoring the LESS. DESIGN   Cross-sectional study. SETTING   United States Military Academy. PATIENTS OR OTHER PARTICIPANTS   A total of 57 healthy, physically active individuals (47 men, 10 women; age = 18.6 ± 0.6 years, height = 174.5 ± 6.7 cm, mass = 75.9 ± 9.2 kg). MAIN OUTCOME MEASURE(S)   Participants completed 3 jump-landing trials that were recorded by standard video cameras and a depth camera. Their movement quality was evaluated by expert LESS raters (standard video recording) using the LESS rubric and by software that automates LESS scoring (depth-camera data). We recorded an error for a LESS item if it was present on at least 2 of 3 jump-landing trials. We calculated κ statistics, prevalence- and bias-adjusted κ (PABAK) statistics, and percentage agreement for each LESS item. Interrater reliability was evaluated between the 2 expert rater scores and between a consensus expert score and the markerless motion-capture system score. RESULTS   We observed reliability between the 2 expert LESS raters (average κ = 0.45 ± 0.35, average PABAK = 0.67 ± 0.34; percentage agreement = 0.83 ± 0.17). The markerless motion-capture system had similar reliability with consensus expert scores (average κ = 0.48 ± 0.40, average PABAK = 0.71 ± 0.27; percentage agreement = 0.85 ± 0.14). However, reliability was poor for 5 LESS items in both LESS score comparisons. CONCLUSIONS   A markerless motion-capture system had the same level of reliability as expert LESS raters, suggesting that an automated system can accurately assess movement. Therefore, clinicians can use the markerless motion-capture system to reliably score the LESS without being limited by the time requirements of manual LESS scoring.

Achilles Tendon Adaptation in Cross-Country Runners Across a Competitive Season

Ultrasound tissue characterization (UTC) is an imaging tool used to quantify tendon structural integrity. UTC has quantified Achilles tendon (AT) acute response to load in athletes; however, AT response to cumulative load over a season is unknown. The purpose of this study was to evaluate AT response across a four‐month competitive season in collegiate cross‐country (XC) runners. Participants (n=21; male=9, female=12; age=19.8±1.2 years; height=171.9±8.9 cm; weight=60.2±8.5 kg) were imaged using the UTC device with a 10‐MHz linear‐array transducer mounted in a tracking device. The device captures images at 0.2 mm intervals along the AT. UTC algorithms quantified the stability of pixel brightness over every 17 contiguous transverse images into four echo types (I‐IV). A total of 168 scans (n=21, bilateral limbs) were performed monthly across the four‐month season (Aug=M1, Sep=M2, Oct=M3, Nov=M4). Echo‐type percentages (%) were calculated from each scan. Generalized estimating equations (GEE) linear regression models evaluated echo‐type % change (β) over the season (M1=reference). Type I increased from M1 to M4 (β=9.10, P<.01; 95%CI: 7.01, 11.21) and Type II decreased from M1 to M3 (β=−2.71, P=.018; 95%CI: −4.96, −0.47) and M1 to M4 (β=−10.19, P<.01; 95%CI: −12.22, −8.17). Type III increased from M1 to M3 (β=0.42, P=.003; 95%CI: 0.19, 0.65) and M1 to M4 (β=0.49, P=.002; 95%CI: 0.18, 0.81), Type IV increased from M1 to M4 (β=0.57, P<.01; 95%CI: 0.29, 0.84). A positive adaptation in AT structural integrity was observed over the XC season, with a ~10% shift from Type II to Type I UTC echo types, suggesting AT resilience to a competitive season of repetitive loading in highly trained runners.

Ankle Dorsiflexion displacement is associated with hip and knee kinematics in females following anterior cruciate ligament reconstruction

ABSTRACT The purpose of this study was to examine associations between ankle dorsiflexion (ankle-DF) displacement and knee and hip kinematics and kinetics during a jump-landing task in females following anterior cruciate ligament reconstruction (ACLR). Females (n = 23) with a history of unilateral ACLR (≥ 6-months post-ACLR) underwent a three-dimensional lower extremity biomechanical evaluation. Pearson Product Moment (r) correlations assessed associations between ankle-DF displacement and knee and hip kinematic and kinetic variables. On the involved-limb, individuals with lesser ankle-DF displacement demonstrated greater knee abduction displacement during the loading phase (r = -0.645, p = 0.001). On the uninvolved-limb, individuals with greater ankle-DF displacement demonstrated greater hip flexion displacement (r = 0.599, p = 0.003) and knee flexion displacement (r = -0.545, p = 0.007). There were no other significant associations between ankle-DF displacement and ankle, knee, or hip biomechanical variables on either limb (p > 0.05). Our findings demonstrate that reduced ankle-DF motion appears to share a different relationship between the involved- and uninvolved-limbs in females post-ACLR.

Quadriceps Neuromuscular Function and Jump-Landing Sagittal-Plane Knee Biomechanics After Anterior Cruciate Ligament Reconstruction

CONTEXT   Aberrant biomechanics may affect force attenuation at the knee during dynamic activities, potentially increasing the risk of sustaining a knee injury or hastening the development of osteoarthritis after anterior cruciate ligament reconstruction (ACLR). Impaired quadriceps neuromuscular function has been hypothesized to influence the development of aberrant biomechanics. OBJECTIVE   To determine the association between quadriceps neuromuscular function (strength, voluntary activation, and spinal-reflex and corticomotor excitability) and sagittal-plane knee biomechanics during jump landings in individuals with ACLR. DESIGN   Cross-sectional study. SETTING   Research laboratory. PATIENTS OR OTHER PARTICIPANTS   Twenty-eight individuals with unilateral ACLR (7 men, 21 women; age = 22.4 ± 3.7 years, height = 1.69 ± 0.10 m, mass = 69.4 ± 10.1 kg, time postsurgery = 52 ± 42 months). MAIN OUTCOME MEASURE(S)   We quantified quadriceps spinal-reflex excitability via the Hoffmann reflex normalized to maximal muscle response (H : M ratio), corticomotor excitability via active motor threshold, strength as knee-extension maximal voluntary isometric contraction (MVIC), and voluntary activation using the central activation ratio (CAR). In a separate session, sagittal-plane kinetics (peak vertical ground reaction force [vGRF] and peak internal knee-extension moment) and kinematics (knee-flexion angle at initial contact, peak knee-flexion angle, and knee-flexion excursion) were collected during the loading phase of a jump-landing task. Separate bivariate associations were performed between the neuromuscular and biomechanical variables. RESULTS   In the ACLR limb, greater MVIC was associated with greater peak knee-flexion angle ( r = 0.38, P = .045) and less peak vGRF ( r = -0.41, P = .03). Greater CAR was associated with greater peak internal knee-extension moment (ρ = -0.38, P = .045), and greater H : M ratios were associated with greater peak vGRF ( r = 0.45, P = .02). CONCLUSIONS   Greater quadriceps MVIC and CAR may provide better energy attenuation during a jump-landing task. Individuals with greater peak vGRF in the ACLR limb possibly require greater spinal-reflex excitability to attenuate greater loading during dynamic movements.

Benign Peripheral Nerve Sheath Tumor in a Distance Runner

A 31-year-old female runner presented to physical therapy via direct access with an 8-month history of atraumatic left lateral calf pain. Following 1 month of physical therapy, the patient was referred to an orthopaedic sports medicine physician. Ultrasound imaging revealed a 2-cm hypoechoic mass with well-defined margins in the left proximal lateral soleus, while Doppler ultrasound demonstrated increased color flow surrounding the mass. Magnetic resonance imaging findings were consistent with a nerve sheath tumor, and ultrasound-guided tissue biopsy determined the mass to be a benign peripheral nerve sheath tumor. J Orthop Sports Phys Ther 2017;47(2):125. doi:10.2519/jospt.2017.6780.