History Of After Anterior Cruciate Ligament Reconstruction Research Articles

Arthroscopic Lysis of Adhesions for Arthrofibrosis After Anterior Cruciate Ligament Reconstruction

Background: Arthrofibrosis (AF) after anterior cruciate ligament reconstruction (ACLR) remains a challenge. There is a paucity of data on arthroscopic interventions for AF after ACLR. Purpose: To (1) describe the patient, injury, and surgical characteristics and patient-reported outcomes (PROs) of those requiring an arthroscopic intervention for loss of motion after ACLR and (2) compare outcomes between patients undergoing an early intervention (within 3 months) versus those undergoing a late intervention (after 3 months). Study Design: Case series; Level of evidence, 4. Methods: Patients with a history of ACLR and a subsequent operative procedure for postoperative AF at a single institution between 2000 and 2018 were retrospectively identified. Arthroscopic interventions included lysis of adhesions, capsular release with or without manipulation under anesthesia, and excision of cyclops lesions. Patients were excluded if they had a knee dislocation or multiple-ligament injury, a periarticular fracture, or less than 2-year follow-up from the arthroscopic intervention. PROs including the Tegner activity score, visual analog scale pain score, and International Knee Documentation Committee score as well as knee range of motion (ROM) were recorded. Results: A total of 40 patients were included with a mean age of 27.2 years (range, 11.0-63.8 years) at surgery and a mean follow-up of 10.0 years (range, 2.9-20.7 years). The mean preoperative flexion and extension were 102° (range, 40°-150°) and 8° (range, 0°-25°), respectively. The mean postoperative flexion and extension were 131° (range, 110° to 150°) and 0° (range, –10° to 5°), respectively. After the arthroscopic intervention, the mean ROM improved from 94° (range, 40°-140°) preoperatively to 131° (range, 107°-152°) at final follow-up (P < .001), and the visual analog scale pain score improved from 3.0 preoperatively to 1.2 postoperatively (P = .001). Overall, 13 patients (32.5%) underwent an intervention within 3 months and 27 (67.5%) after 3 months. The early intervention group had a higher postoperative International Knee Documentation Committee score compared with the late intervention group (86.8 vs 71.7, respectively; P = .035). Conclusion: An arthroscopic intervention for AF after ACLR successfully improved knee ROM and pain. Patients who underwent either early or late surgery obtained satisfactory motion and function, although improved PROs were observed when the intervention occurred within 3 months of the primary procedure.

Residual Deficits in Reactive Strength After Anterior Cruciate Ligament Reconstruction in Soccer Players.

Deficits in plyometric abilities are common after anterior cruciate ligament reconstruction (ACLR). Vertical rebound tasks may provide a targeted evaluation of knee function. To examine the utility of a vertical hop test for assessing function after ACLR and establishing factors associated with performance. Cross-sectional study. Rehabilitation program. Soccer players with a history of ACLR (n = 73) and matched control individuals (n = 195). The 10-second vertical hop test provided measures of jump height, the Reactive Strength Index (RSI), and asymmetry. We also examined possible predictors of hop performance, including single-legged vertical drop jump, isokinetic knee-extension strength, and the International Knee Documentation Committee questionnaire score. Between-limbs differences were identified only for the ACLR group, and asymmetry scores increased in those with a history of ACLR (P < .001) compared with the control group. The single-legged vertical drop jump, RSI, and knee-extension torque were significant predictors of 10-second hop height (R2 = 20.1%) and RSI (R2 = 47.1%). Vertical hop deficits were present after ACLR, even after participants completed a comprehensive rehabilitation program. This may have been due to reduced knee-extension and reactive strength. Vertical hop tests warrant inclusion as part of the return-to-sport test battery.

Single-leg triple hop propulsion strategies in females with and without a history of ACLR.

The single-leg triple hop is a commonly used functional task following anterior cruciate ligament reconstruction (ACLR). However, recent research suggests that individuals may utilize a compensatory propulsion strategy to mask underlying quadriceps dysfunction and achieve symmetrical hop performance. Evaluate the performance and propulsion strategies employed by females with and without ACLR during a single-leg triple hop. Cross-sectional. Laboratory. Thirty-eight females (ACLR=19, 19.2±1.8 years, 1.64±0.70m, 63.8±7.6 kg; Control=19, 21.1±3.3 years, 1.67±0.73m, 67.3±9.3 kg). Hop distance and limb symmetry index (LSI) were assessed during a single-leg triple hop for distance. Propulsion strategies were assessed during the first and second hops of the single-leg triple hop. Separate two-way ANOVA models were used to assess the influence of ACLR, joint and their interaction on mechanical joint work, moment impulse and the relative joint contributions to total work and impulse in females with and without a history of ACLR. Despite achieving a mean LSI of ~96%, females with ACLR produced less total work in their reconstructed limb compared bilaterally during single-leg triple hop propulsion (First Hop: p=.002; Second Hop: p=.02). During the first and second hop, the reconstructed knee produced 19.3% (p=.03) and 27.3% (p=.001) less work compared bilaterally. No significant differences were identified between limbs in moment impulse (First Hop: p=.67; Second Hop: p=.76). Irrespective of limb or group, the ankle was the largest contributor to both work and moment during both first and second hops (p<.001). Clinicians should caution against using a single-leg triple hop as a surrogate for restored lower extremity function in females post-ACLR. This recommendation is driven by the compelling findings that knee joint deficits persist in the reconstructed limb despite achieving ~96% LSI and that regardless of previous injury status, single-leg triple hop propulsion is predominantly driven by the ankle.

Are Elite Collegiate Female Athletes PRIME for a Safe Return to Sport after ACLR? An Investigation of Physical Readiness and Integrated Movement Efficiency (PRIME).

BackgroundElite female athletes who successfully return to sport after anterior cruciate ligament reconstruction (ACLR) represent a high-risk group for secondary injury. Little is known about how the functional profile of these athletes compares to their teammates who have not sustained ACL injuries.PurposeTo compare elite collegiate female athletes who were able to successfully return to sport for at least one season following ACLR to their teammates with no history of ACLR with regard to self-reported knee function, kinetics, and kinematics during a double limb jump-landing task.Study DesignCross-Sectional StudyLevel of EvidenceLevel 3MethodsEighty-two female collegiate athletes (17 ACLR, 65 control) completed the knee-specific SANE (single assessment numeric evaluation) and three trials of a jump-landing task prior to their competitive season. vGRF data on each limb and the LESS (Landing Error Scoring System) score were collected from the jump-landing task. Knee-SANE, vGRF data, and LESS scores were compared between groups. All athletes were monitored for the duration of their competitive season for ACL injuries.ResultsAthletes after ACLR reported worse knee-specific function. Based on vGRF data, they unloaded their involved limb during the impact phase of the landing, and they were more asymmetrical between limbs during the propulsion phase as compared to the control group. The ACLR group, however, had lower LESS scores, indicative of better movement quality. No athletes in either group sustained ACL injuries during the following season.ConclusionDespite reporting worse knee function and demonstrating worse kinetics, the ACLR group demonstrated better movement quality relative to their uninjured teammates. This functional profile may correspond to short-term successful outcomes following ACLR, given that no athletes sustained ACL injuries in the competition season following assessment.

Suppressed quadriceps fascicle behavior is present in the surgical limbs of those with a history of ACL reconstruction

The balance of published data have largely focused on adaptations in muscle and fiber size after anterior cruciate ligament reconstruction (ACLR), failing to account for the dynamic changes in the behavior of the muscles’ contractile elements that strongly contribute to force production. To better understand the sources of quadriceps dysfunction, the purpose of our research was to determine if alterations in fascicle behavior are present after ACLR. Unilateral ACLR individuals (9 m/9f; 21 ± 3 yrs; 1.74 ± 0.12 m;71.58 ± 13.31 kg; months from surgery:38 ± 36) and healthy controls (3 m/6f; 23 ± 2 yrs; 1.67 ± 0.10 m; 63.51 ± 10.11 kg) participated. In-vivo vastus lateralis fascicle behavior was recorded using ultrasonography during three maximal isokinetic knee extensions (60°·s−1). Fascicle length, angle, and shortening velocity were calculated and analyzed from rest to peak torque. Peak knee extension torque was averaged between isokinetic trials (Nm·kg−1). Group by limb interactions were assessed using separate two-way analyses of variance and were further evaluated by comparing 95% confidence intervals where appropriate. Significant interactions were present for fascicle angle at peak torque (P = 0.01), fascicle length excursion (P = 0.05), fascicle angle excursion (P < 0.01), fascicle shortening velocity (P = 0.05) and strength (P = 0.03). Upon post-hoc evaluation, the surgical limb displayed altered in-vivo fascicle behavior compared to all limbs (P < 0.05) and reduced strength compared to the contralateral and right control limbs (P < 0.05). No other significant interactions were present (P > 0.05). Our data show that those with a history of ACLR have fascicles that are slower, lengthen less and operate with lower angles relative to the axis of force production. Altered fascicle behavior after ACLR may be an important underlying factor to explaining the protracted quadriceps dysfunction.

The Relationship Between Injury-Related Fear and Visuomotor Reaction Time in Individuals With a History of Anterior Cruciate Ligament Reconstruction.

Deficits in reaction time, decreased self-reported knee function, and elevated levels of injury-related fear have been observed in individuals who sustain anterior cruciate ligament injury. Understanding the relationship between these variables may provide the impetus to further investigate effective intervention strategies to address these deficits in individuals after anterior cruciate ligament reconstruction (ACLR). To examine the relationship between injury-related fear and lower-extremity visuomotor reaction time (VMRT) in individuals with a history of ACLR. A secondary purpose was to determine the relationship between self-reported knee function and lower-extremity VMRT in individuals with a history of ACLR. Cross-sectional study. Laboratory. Twenty participants between the ages of 18-35years, with history of unilateral ACLR within the last 10 years, who injured their knee playing or training for organized or recreational sports. Scores on the athlete fear avoidance questionnaire, the fear-avoidance beliefs questionnaire (FABQ), the knee injury and osteoarthritis outcome score, and reaction time (in seconds) on the lower-extremity VMRT task using the FitLight Trainer™, bilaterally. Spearman Rho correlations examined the relationship between the dependent variables. There was a moderate positive correlation between VMRT and FABQ-total (r = .62, P < .01), FABQ-sport (r = .56, P = .01), and FABQ-physical activity (r = .64, P < .01) for the injured limb. Correlations between FABQ scores and VMRT for the uninjured limb were weak positive correlations (r = .36-.41, P > .05). Weak correlations between the osteoarthritis outcome score subscales, athlete fear avoidance questionnaire, and VMRT were observed for the injured limb (P > .05). Individuals with a history of ACLR who exhibited elevated levels of injury-related fear demonstrated slower VMRT. There were no relationships between self-reported knee function and VMRT. Future research should explore interventions to address injury-related fear and VMRT in individuals after ACLR.

Lower Limb Kinetic Asymmetries in Professional Soccer Players With and Without Anterior Cruciate Ligament Reconstruction: Nine Months Is Not Enough Time to Restore “Functional” Symmetry or Return to Performance

Background: Residual between-limb deficits are a possible contributing factor to poor outcomes in athletic populations after anterior cruciate ligament reconstruction (ACLR). Comprehensive appraisals of movement strategies utilized by athletes at key clinical milestones during rehabilitation are warranted. Purpose: To examine kinetic parameters recorded during a countermovement jump with a force platform in healthy professional soccer players and to compare their performance with those who had undergone ACLR at different stages of their rehabilitation. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 370 male professional soccer players attended a physical screening assessment where they performed at counter jump movement protocol on dual force plates and were divided into 4 groups: group 1 (<6 months post-ACLR), group 2 (6-9 months post-ACLR), group 3 (>9 months post-ACLR), and group 4 (healthy matched controls). Results: Players in the later phases of rehabilitation increased their jump performance; however, values were significantly lower than those of healthy matched controls (P > .05). Significant between-limb differences were present for both eccentric- and concentric-phase variables (P < .05), with effect sizes ranging from moderate to very large (d = 0.42-1.35). Asymmetries were lower in players who were further away from surgery; however, between-limb differences remained significantly greater in players >9 months after ACLR versus matched controls—specifically, for concentric impulse, concentric peak force, eccentric deceleration impulse, and eccentric deceleration rate of force development asymmetry (P < .05). Logistic regression identified concentric impulse asymmetry as being most strongly associated with a history of ACLR when group prediction analysis was performed (ACLR group 1, 2, or 3 vs matched controls), with odds ratios ranging from 1.50 to 1.91. Conclusion: Between-limb deficits in key eccentric and concentric loading parameters remain >9 months after ACLR, indicating a compensatory offloading strategy to protect the involved limb during an athletic performance task. Concentric impulse asymmetry could be considered an important variable to monitor during rehabilitation.

Professional Advancement and Performance of Amateur Baseball Players Selected in the Major League Baseball Draft With Previous Anterior Cruciate Ligament Reconstruction

Background: The effect that an anterior cruciate ligament injury requiring reconstructive surgery has on the professional advancement and performance of amateur baseball players selected in the Major League Baseball draft is not known. Return to sports after anterior cruciate ligament reconstruction (ACLR) in professional athletes has been shown to be high, but mixed results with regard to performance and return to preinjury level have been demonstrated in other sports. Purpose: To (1) investigate the highest level of professional advancement among Major League Baseball draftees with a history of ACLR before entering the draft, (2) examine how much time these players spent on the disabled list (DL) and determine if it was related to the knee, and (3) compare the batting and pitching performance of these players against healthy matched controls. Study Design: Cohort study; Level of evidence, 3. Methods: Predraft medical records of all players selected in the Major League Baseball draft from 2004 to 2008 were reviewed. Players with a documented anterior cruciate ligament injury treated with ACLR before the draft were included. For each study player, 3 controls were identified. Data were accumulated from the time when players were drafted through the 2015 season. Outcome variables included highest professional level of advancement, DL time, and batting and pitching performance. Results: Forty draftees with a history of ACLR (22 pitchers, 18 position players) were identified and matched to 120 controls (66 pitchers, 54 position players). The difference in the highest level of professional advancement between the groups was not statistically significant (P = .488). The mean total number of times and the mean total number of days on the DL were similar between the groups (1.83 vs 1.47, P = .297; 121.54 vs 109.62, P = .955); however, the mean number of times on the DL because of a knee injury was significantly different (0.28 vs 0.11, P = .004), as was the mean number of days on the DL because of a knee injury (17.36 vs 7.72, P = .009). Among pitchers, there were no differences in performance. Similarly, there were no differences among position players in batting performance. Conclusion: There was no difference between draftees with a history of ACLR and their controls in terms of advancement from the minor to the major leagues. Additionally, pitching and batting performance were similar. Although the 2 groups spent similar time on the DL, the ACLR group spent more time on the DL because of a knee injury than the control group.

Protracted alterations in muscle activation strategies and knee mechanics in patients after Anterior Cruciate Ligament Reconstruction.

Altered quadriceps muscle activity can contribute to reduced ability of the muscle to quickly generate force and appropriately attenuate landing forces, exacerbating poor landing and movement strategies commonly seen after anterior cruciate ligament reconstruction (ACLR). The purpose was to evaluate if electromyographic (EMG) activity and knee biomechanics during a single-limb forward hop task are influenced by a history of ACLR. Twenty-six individuals with a history of unilateral ACLR (age 20.2 ± 2.7years, height 1.7 ± 0.1m; weight 69.6 ± 12.4kg; time from surgery, 2.9 ± 2.7years; graft type, 21 bone-patellar-tendon bone, 5 hamstring) and 8 healthy controls (age 23.3 ± 1.8years, height 1.7 ± 0.1m; mass 66.3 ± 13.9kg) volunteered. Sagittal plane knee kinetics and EMG of the vastus lateralis were synchronized and measured using a three-dimensional motion analysis system during a single-limb forward hop task. Mixed-effect models were used to assess the effect of group on kinetic and EMG variables. Kinetic outcomes (peak and rate of knee extension moment) and temporal muscle activity and activation patterns differed between the ACLR limb and healthy-control limb. Inter-limb asymmetries in the ACLR group were observed for all variables except EMG onset time; no limb differences were observed in the healthy cohort. Years after ACLR, persistent quadriceps functional deficits are present, contributing to altered neuromuscular control strategies during functional tasks that may increase the risk of reinjury. To counteract these effects, emerging evidence indicates that clinicians could consider the use of motor learning strategies to improve neuromuscular control after ACLR. III.

Fear-Avoidance Beliefs and Health-Related Quality of Life in Post-ACL Reconstruction and Healthy Athletes: A Case-Control Study.

Many athletes return to sport after anterior cruciate ligament reconstruction (ACLR) with lingering physical or mental health impairments. Examining health-related quality of life (HRQL) and fear-avoidance beliefs across the spectrum of noninjured athletes and athletes with a history of ACLR may provide further insight into targeted therapies warranted for this population. The purpose of this study was to examine differences in fear-avoidance beliefs and HRQL in college athletes with a history of ACLR not participating in sport (ACLR-NPS), participating in sport (ACLR-PS), and healthy controls (Control) with no history of injury participating in sport. Cross-sectional. Laboratory. Patients (or Other Participants): A total of 10 college athletes per group (ACLR-NPS, ACLR-PS, and Control) were included. Participants were included if on a roster of a Division I or III athletic team during data collection. Participants completed a demographic survey, the modified Disablement in the Physically Active Scale (mDPA) to assess HRQL, and Fear-Avoidance Beliefs Questionnaire (FABQ) to assess fear-avoidance beliefs. Scores on the mDPA (Physical and Mental) and FABQ subscales (Sport and Physical Activity) were calculated, a 1-way Kruskal-Wallis test and separate Mann-Whitney U post hoc tests were performed (P < .05). ACLR-NPS (30.00 [26.00]) had higher FABQ-Sport scores than ACLR-PS (18.00 [26.00]; P < .001) and Controls (0.00 [2.50]; P < .001). ACLR-NPS (21.50 [6.25]) had higher FABQ-Physical Activity scores than ACLR-PS (12.50 [13.00]; P = .001) and Controls (0.00 [1.00]; P < .001). Interestingly, ACLR-PS scores for FABQ-Sport (P = .01) and FABQ-Physical Activity (P = .04) were elevated compared with Controls. ACLR-NPS had higher scores on the mDPA-Physical compared with the ACLR-PS (P < .001) and Controls (P < .001), and mDPA-Mental compared with ACLR-PS (P = .01), indicating decreased HRQL. The ACLR-NPS had greater fear-avoidance beliefs and lower HRQL compared with ACLR-PS and Controls. However, the ACLR-PS had higher scores for both FABQ subscales compared with Controls. These findings support the need for additional psychosocial therapies to address fear-avoidance beliefs in the returned to sport population.

Sex Differences on the Landing Error Scoring System Among Individuals With Anterior Cruciate Ligament Reconstruction

After anterior cruciate ligament reconstruction (ACLR), women have a greater risk of incurring a second anterior cruciate ligament injury and they display different landing movement patterns than men. It remains unclear if clinical movement-assessment tools, such as the Landing Error Scoring System (LESS), can detect sex differences in movement patterns after ACLR. To compare total LESS scores and individual LESS errors between men and women with a history of ACLR. Cross-sectional study. Laboratory. A total of 168 individuals (41 men and 127 women; mean age: men = 20 years [range, 19-25 years], women = 19 years [range, 18-20 years]; mean time since surgery: men = 21 months [range, 12-36 months], women = 27.5 months [range, 17-39 months]) with a history of primary, unilateral ACLR. Participants completed a minimum of 3 trials of a drop vertical-jump task scored using the LESS. The between-sexes difference in LESS score was assessed using analysis of covariance, whereas the associations between participant sex and errors on each LESS item were assessed using logistic or multinomial regression. Women displayed a greater number of total landing errors (men = 4.6 ± 2.3, women = 6.1 ± 2.3; P < .001) and were more likely to commit errors in trunk flexion at initial contact (men = 4.9%, women = 23.6%; odds ratio [OR] = 4.94), medial knee position at initial contact (men = 17.1%, women = 42.5%; OR = 6.01), medial knee displacement (men = 24.4%, women = 73.2%; OR = 7.88), total joint displacement (1 error: men = 58.5%, women = 71.7%, OR = 2.10; 2 errors: men = 7.3%, women = 14.2%, OR = 3.71), and overall impression (1 error: men = 75.6%, women = 84.3%, OR = 3.24; 2 errors: men = 2.4%, women = 10.2%, OR = 12.89) compared with men. Women with ACLR displayed worse LESS scores and were more likely to commit errors related to medial knee displacement and overall landing quality than men with ACLR.

2D AND 3D KINEMATICS DURING LATERAL STEP-DOWN TESTING IN INDIVIDUALS WITH ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

The lateral step-down test is an established clinical evaluation tool to assess quality of movement in patients with knee disorders. However, this test has not been investigated in individuals after anterior cruciate ligament reconstruction (ACLR) in association with quantitative 3D motion analysis. The purpose of this study was to determine the strength of association between visually-assessed quality of movement during the lateral step-down test and 3D lower limb kinematics in patients with history of ACLR. A second purpose was to compare kinematics between subgroups based on the presence or absence of faulty alignments during the task. The final purpose was to compare visually-assessed quality of movement scores between box heights during lateral step-down testing. Twenty subjects at least one year status post-ACLR (18 females, age of 24.5 ± 4.6 years and body mass index of 23.4 ± 2.3 kg/m2) performed the lateral step-down test unilaterally on the surgical limb atop four and six inch boxes. A board-certified orthopedic physical therapist scored overall quality of movement during the lateral step-down test using established criteria during 2D video playback. Lower limb kinematics were simultaneously collected using 3D motion capture. An alpha level of 0.05 was used for all statistical treatments. Overall 2D quality of movement score significantly correlated (r =0.47-0.57) with 3D hip adduction and hip internal rotation across box heights. Across box heights, the presence of faulty pelvic alignment differentiated a subgroup exhibiting less peak knee flexion, and the presence of faulty knee alignment differentiated a subgroup exhibiting greater peak hip adduction. The six inch box elicited worse quality of movement compared to the four inch box. These results suggest that visually-assessed quality of movement is associated with several kinematic variables after ACLR. 2D movement deviations at the pelvis appear to consistently relate to less knee flexion, and 2D deviations at the knee appear to suggest greater hip adduction. Generally, poorer quality of movement was observed for the six inch box height. Clinically, these data suggest that interventions targeting hip abductor and knee extensor strength and neuromuscular control may be useful in the presence of poor quality of movement during lateral step-down testing. 2b.

Unilateral Quadriceps Strengthening With Disinhibitory Cryotherapy and Quadriceps Symmetry After Anterior Cruciate Ligament Reconstruction.

The effect of unilateral cryotherapy-facilitated rehabilitation exercise on involved-limb quadriceps function and limb symmetry in individuals with quadriceps dysfunction after anterior cruciate ligament reconstruction (ACLR) remains unclear. To measure the effect of a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening program on knee-extension strength and quadriceps central activation ratio (CAR) in participants with ACLR. Controlled laboratory study. Laboratory. A total of 10 volunteers with unilateral ACLR (1 man, 9 women; age = 21.0 ± 2.8 years, height = 164.6 ± 5.0 cm, mass = 64.0 ± 6.1 kg, body mass index = 23.7 ± 2.7 kg/m2) and 10 healthy volunteers serving as control participants (1 man, 9 women; age = 20.8 ± 2.5 years, height = 169.1 ± 6.2 cm, mass = 61.1 ± 6.4 kg, body mass index = 21.4 ± 2.3 kg/m2) participated. Participants with ACLR completed a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening intervention. Bilateral normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps CAR (%) were assessed preintervention and postintervention. Limb symmetry index (LSI) was calculated at preintervention and postintervention testing. Preintervention between-groups differences in unilateral quadriceps function and LSI were evaluated using independent-samples t tests. Preintervention-to-postintervention differences in quadriceps function were evaluated using paired-samples t tests. Cohen d effect sizes (95% confidence interval [CI]) were calculated for each comparison. Preintervention between-groups comparisons revealed less knee-extension MVIC torque and quadriceps CAR for the ACLR limb (MVIC: P = .01, Cohen d = -1.31 [95% CI = -2.28, -0.34]; CAR: P = .004, Cohen d = -1.48 [95% CI = -2.47, -0.49]) and uninvolved limb (MVIC: P = .03, Cohen d = -1.05 [95% CI = -1.99, -0.11]; CAR: P = .01, Cohen d = -1.27 [95% CI = -2.23, -0.31]) but not for the LSI (MVIC: P = .46, Cohen d = -0.34 [95% CI = -1.22, 0.54]; CAR: P = .60, Cohen d = 0.24 [95% CI = -0.64, 1.12]). In the ACLR group, participants had improved knee-extension MVIC torque in the involved limb ( P = .04, Cohen d = 0.32 [95% CI = -0.56, 1.20]) and uninvolved limb ( P = .03, Cohen d = 0.29 [95% CI = -0.59, 1.17]); however, the improvement in quadriceps CAR was limited to the involved limb ( P = .02, Cohen d = 1.16 [95% CI = 0.21, 2.11]). We observed no change in the LSI with the intervention for knee-extension MVIC torque ( P = .74, Cohen d = 0.09 [95% CI = -0.79, 0.97]) or quadriceps CAR ( P = .61, Cohen d = 0.26 [95% CI = -0.62, 1.14]). Two weeks of cryotherapy-facilitated exercise may improve involved-limb quadriceps function while preserving between-limbs symmetry in patients with a history of ACLR.

Total Knee Arthroplasty After Anterior Cruciate Ligament Reconstruction: Not Just a Routine Primary Arthroplasty.

Despite the success of restoring joint stability and improving early functional outcomes after anterior cruciate ligament (ACL) reconstruction, the long-term risk of developing symptomatic osteoarthritis requiring total knee arthroplasty is higher than that in the uninjured population. The purpose of this study was to compare operative characteristics and early outcomes of patients undergoing total knee arthroplasty after ACL reconstruction with those of a matched cohort of control subjects with primary osteoarthritis and no history of ligament reconstruction. All patients who had undergone total knee arthroplasty from 2005 to 2013 at our institution with a history of ACL reconstruction and a minimum 2-year follow-up were identified from a prospective research database. These patients were matched by demographic and surgeon variables to patients who had not undergone prior ACL reconstruction. Outcomes included Knee Society Scores (KSS), range of motion, operative variables, complications, and reoperations. A cohort of 122 patients was identified as the ACL study group and was compared with the matched control cohort. The mean age at the time of the surgical procedure was 58 years, and 55% of the patients were male. The mean follow-up was 3.3 years in the ACL group and 3.0 years in the control group. There was no significant difference in the latest KSS outcomes between groups postoperatively (p > 0.05). Although preoperative flexion was significantly lower (p = 0.01) in the ACL group (119°) than in the control group (123°), there was no difference between groups postoperatively. Fifty percent (61 of 122) of patients in the ACL group required implant removal at the time of total knee arthroplasty. The operative time was significantly longer (p < 0.001) in the ACL group (88 minutes) compared with the control group (73 minutes). There were a total of 11 reoperations in the ACL group, including 4 for periprosthetic infection, whereas there were only 2 reoperations in the control group. The risk of reoperation in the ACL group was more than 5 times higher than in the control group (relative risk, 5.5 [95% confidence interval, 1.2 to 24.3]; p = 0.01). The results of this retrospective matched cohort study suggest that prior ACL reconstruction results in longer operative time and increased risk of early reoperation after total knee arthroplasty. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Persistent Muscle Inhibition after Anterior Cruciate Ligament Reconstruction: Role of Reflex Excitability.

Persistent voluntary quadriceps activation deficits are common after anterior cruciate ligament reconstruction (ACLR), but the direct causes are unclear. The primary purpose of this study was to determine whether spinal reflex excitability deficits are present in individuals with a history of ACLR, and secondarily to determine whether spinal reflex excitability predicts which individuals possess full voluntary quadriceps activation. One hundred and forty-seven individuals (74 healthy and 73 ACLR) participated in this cross-sectional case-control study. Quadriceps spinal reflex excitability was quantified using the Hoffmann reflex normalized to the maximal muscle response (H:M ratio). Voluntary quadriceps activation was evaluated with the burst superimposition technique and calculated via the central activation ratio (CAR). Separate 2 × 2 ANCOVA tests were used to compare between-limb and between-group differences for H:M ratio and CAR. A receiver operating characteristic curve was used to determine the accuracy of H:M ratio to predict if ACLR participants present with full voluntary activation (CAR ≥ 0.95). The ACLR H:M ratio was not different between limbs or compared with the healthy group (P > 0.05). Although ACLR CAR was lower bilaterally compared with the healthy group (P < 0.001), it did not differ between limbs. The H:M ratio has poor accuracy for predicting which individuals exhibit full voluntary activation (receiver operating characteristic area under the curve = 0.52, 95% CI = 0.37,0.66; odds ratio = 2.2, 95% CI = 0.8, 5.9). Spinal reflex excitability did not differ between limbs in individuals with ACLR or compared with healthy participants. The level of quadriceps spinal reflex excitability has poor accuracy at predicting which ACLR individuals would demonstrate full voluntary quadriceps activation.

Jump-landing mechanics after anterior cruciate ligament reconstruction: a landing error scoring system study.

The Landing Error Scoring System (LESS) is a clinical evaluation of jump-landing mechanics and may provide useful information in assisting with return-to-sport decisions in patients after anterior cruciate ligament reconstruction (ACLR). However, it is currently unknown how patients with ACLR perform on the LESS compared with healthy controls. To determine if the total LESS score differed between individuals with ACLR and healthy controls and to determine the types of errors that differ between groups. Cross-sectional study. Research laboratory. A total of 27 individuals with unilateral ACLR (age = 19.8 ± 1.8 years, height = 170 ± 5.5 cm, mass = 68.8 ± 11.9 kg) and 27 controls (age = 20.5 ± 1.7 years, height = 169 ± 8.4 cm, mass = 66.6 ± 9.0 kg) with no history of ACLR. Each participant completed 3 trials of a standardized jump-landing task. Each jump landing was assessed for specific postures using standardized LESS criteria by a blinded evaluator. Individual LESS items were summed to create a total LESS score. The dominant limb was assessed in the control group, and the reconstructed limb was assessed in the ACLR group. The ACLR group had higher LESS scores compared with controls (ACLR: 6.7 ± 2.1 errors, control: 5.6 ± 1.5 errors, P = .04). Additionally, the ACLR group was more likely to err when landing with lateral trunk flexion (Fisher exact test, P = .002). Individuals with ACLR had worse landing mechanics as measured by the LESS. Lateral trunk deviation may be related to quadriceps avoidance in the reconstructed limb or poor trunk neuromuscular control. The LESS is useful for evaluating landing errors in patients with ACLR and may help to identify areas of focus during rehabilitation and before return to sport.

Quadriceps Strength and Corticospinal Excitability as Predictors of Disability After Anterior Cruciate Ligament Reconstruction

Disability is common in a proportion of patients after anterior cruciate ligament reconstruction (ACL-R). Neuromuscular quadriceps deficits are a hallmark impairment after ACL-R, yet the link between muscle function and disability is not understood. To evaluate the ability of quadriceps strength and cortical excitability to predict self-reported disability in patients with ACL-R. Fifteen participants with a history of ACL-R (11 female, 4 male; 172 ± 9.8 cm, 70.4 ± 17.5 kg, 54.4 ± 40.9 mo postsurgery) were included in this study. Corticospinal excitability was assessed using active motor thresholds (AMT), while strength was assessed with maximal voluntary isometric contractions (MVIC). Both voluntary strength and corticospinal excitability were used to predict disability measured with the International Knee Documentation Committee Index (IKDC). The overall multiple-regression model significantly predicted 66% of the variance in self-reported disability as measured by the IKDC index (R2 = .66, P = .01). Initial imputation of MVIC into the model accounted for 61% (R2 = .61, P = .01) of the variance in IKDC. The subsequent addition of AMT into the model accounted for an insignificant increase of 5% (Δ R2 = .05, P = .19) in the prediction capability of the model. Quadriceps voluntary strength and cortical excitability predicted two-thirds of the variance in disability of patients with ACL-R, with strength accounting for virtually all of the predictive capability of the model.

Cyclops Lesions That Occur in the Absence of Prior Anterior Ligament Reconstruction1

Loss of full extension after anterior cruciate ligament (ACL) reconstruction, with development of an audible and palpable "clunk" with terminal extension was first described by Jackson and Schaefer as "cyclops syndrome." This syndrome, which is the result of a fibrous nodule (termed a cyclops nodule), has recently been described in patients who have sustained ACL injury but have not undergone reconstructive surgery. From 2001 to 2006, the authors identified 10 patients (five women and five men, ages 27-76 years) with cyclops nodules seen at magnetic resonance (MR) imaging. All patients had a history of trauma but no history of ACL reconstruction. The cyclops lesions had a mean size of 16 x 12 x 11 mm, with 90% of them located just anterior to the distal ACL. MR imaging showed a well-defined, somewhat heterogeneous soft-tissue nodule with a signal intensity typically similar to that of skeletal muscle. The authors suspect that the cause of cyclops lesions that occur in the absence of ACL reconstruction is similar to that suggested in the classic postoperative patient. Cyclops syndrome should be suspected in any patient in whom an ACL nodule is identified at MR imaging, and similarly a cyclops nodule should be considered as a possible cause of loss of extension in any patient who has sustained ACL injury. Movies available at http://radiographics.rsnajnls.org/cgi/content/full/e26/DC1.