The Longitudinal Neurophysiological Adaptation of a Division I Female Lacrosse Player Following Anterior Cruciate Rupture and Repair: A Case Report.

Background: Neurophysiological adaptation following anterior cruciate ligament (ACL) rupture and repair (ACLR) is critical in establishing neural pathways during the rehabilitation process. However, there is limited objective measures available to assess neurological and physiological markers of rehabilitation. Purpose: To investigate the innovative use of quantitative electroencephalography (qEEG) to monitor the longitudinal change in brain and central nervous systems activity while measuring musculoskeletal function during an anterior cruciate ligament repair rehabilitation. Case Description: A 19 year-old, right-handed, Division I NCAA female lacrosse midfielder suffered an anterior cruciate ligament rupture, with a tear to the posterior horn of the lateral meniscus of the right knee. Arthroscopic reconstruction utilizing a hamstring autograft and a 5% lateral meniscectomy was performed. An evidence-based ACLR rehabilitation protocol was implemented while using qEEG. Outcomes: Central nervous system, brain performance and musculoskeletal functional biomarkers were monitored longitudinally at three separate time points following anterior cruciate injury: twenty-four hours post ACL rupture, one month and 10 months following ACLR surgery. Biological markers of stress, recovery, brain workload, attention and physiological arousal levels yielded elevated stress determinants in the acute stages of injury and were accompanied with noted brain alterations. Brain and musculoskeletal dysfunction longitudinally reveal a neurophysiological acute compensation and recovering accommodations from time point one to three. Biological responses to stress, brain workload, arousal, attention and brain connectivity all improved over time. Discussion: The neurophysiological responses following acute ACL rupture demonstrates significant dysfunction and asymmetries neurocognitively and physiologically. Initial qEEG assessments revealed hypoconnectivity and brain state dysregulation. Progressive enhanced brain efficiency and functional task progressions associated with ACLR rehabilitation had notable simultaneous improvements. There may be a role for monitoring CNS/brain state throughout rehabilitation and return to play. Future studies should investigate the use of qEEG and neurophysiological properties in tandem during the rehabilitation progression and return to play.

Plate osteosynthesis of midshaft clavicle fractures in adolescent contact sports athletes - adolescent clavicle fracture.

Surgical treatment of mid-shaft clavicle fractures via anatomical plates in adult athletes is documented to be safe and effective. Functional and cosmetic outcomes in adolescent contact sports athletes have not been well documented. Adolescent athletes (age 11-19) surgically treated for mid-shaft clavicle fractures between 1 May 2011 and 30 October 2017 were included in this study. Twenty-one adolescent athletes with a mean follow-up of 44 months were reviewed. Retrospective chart reviews were performed. Functional and cosmetic outcomes, return to sports time/rate were analyzed using Nottingham Clavicle Scores and a 'Custom Questionnaire'. Return of function and healing, evidenced on radiographs, was achieved in all 21 patients. All patients returned back to competitive sports. The mean time to return back to training was 45.9 ± 16 (24-76) days. Sixteen (76.1%) of the patients reported Nottingham Clavicle Scores with a mean score of 91.7 (85-98). In the Custom Questionnaire, 16 patients who participated in the phone interview were satisfied with the cosmetic outcomes. The most common complaint was implant prominence and irritation in 6 (40%) patients, subsequently requiring implant removal in 3 (18.8%). Surgical fixation of mid-shaft clavicle fractures can lead to excellent union and cosmetic outcomes and a rapid return to sports in adolescent contact sport athletes. However, one should consider the outcomes of implant-related complaints and the possibility of implant removal surgery in the future.

Graft choice or drilling technique does not influence outcomes of ACL reconstruction in patients over forty-five.

PURPOSE: To evaluate whether graft-type and tunnel location in ACL reconstruction impact patient-reported outcomes in individuals over the age of 45. METHODS: From 2015 to 2018, patients over 45 years old undergoing primary ACL reconstruction without multi-ligamentous injuries were enrolled in an institutional registry. Baseline International Knee Documentation Committee (IKDC) subjective scores, Knee Injury and Osteoarthritis Outcome Scores (KOOS), Marx Activity Scale, and patient characteristics were collected. Follow-up occurred at a minimum of two years to obtain patient-reported outcomes. RESULTS: Of the 51 patients who qualified for the study, 44 (86.3%) patients were available at a minimum of two years after surgery date (range 24-60 months). Average age at time of surgery of the available patients was 51.6 ± 4.87 (range 45-66). Between femoral tunnel drilling methods, there were no differences in the proportion of patients achieving clinically significant improvement or post-operative outcome scores. While patients who received patellar tendon autografts were more likely to achieve clinically significant improvement in the KOOS sports subscale, there were no other differences in outcomes measures between graft types. Two patients had a retear of their graft, and an additional five patients complained of subjective instability. CONCLUSIONS: In patients over the age of 45, neither the method used to create the femoral tunnel nor the graft type used in ACL reconstruction caused a significant difference in post-operative PROMs with a minimum of two years of follow-up. LEVEL OF EVIDENCE: Therapeutic IV, Case Series.

Mandatory Prescription Limits and Opioid Use After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Because of the need for perioperative pain management, orthopaedic surgeons play an important role in opioid use. PURPOSE/HYPOTHESIS: To evaluate the impact of opioid-limiting legislation on postoperative opioid use and pain-related complications after anterior cruciate ligament reconstruction (ACLR). The hypothesis was that the opioid-limiting legislation would reduce postoperative opioid use after ACLR. STUDY DESIGN: Cohort study; level of evidence, 3. METHODS: We retrospectively reviewed patients who underwent ACLR 1 year before and 1 year after Ohio's opioid-limiting legislation, which was passed in August 2017. Clinicians were prohibited from prescribing more than 30 morphine milligram equivalents (MMEs) per day, with a maximum duration of 7 days for adults. The Ohio Automated Rx Reporting System database and patients' medical charts were reviewed for prescriptions of all controlled substances (oral oxycodone, hydrocodone, morphine, codeine, tramadol, and hydromorphone) filled from 30 days before and 90 days after ACLR. The total number of postoperative prescriptions, total MMEs, the number of pills in each patient's prescription, and pain-related complications (emergency department visits, office calls for pain control issues, unplanned readmissions, unplanned surgeries, and provider notes indicating opioid prescription refill demands) were evaluated. RESULTS: A total of 243 patients (127 prelegislation, 116 postlegislation) were included in the study. There were no significant differences in demographics or preoperative opioid use between the study groups. The number of pills prescribed initially decreased by 34% after legislation (63.5 ± 16.7 [prelegislation] vs 42 ± 15.7 pills [postlegislation]; P < .001). Correspondingly, there was a significant decrease in total quantity of initial prescriptions in the postlegislation period (474.6 ± 123.8 vs 310.7 ± 115.3 MMEs; P < .001). The number of documented pain medication refill demands and pain-related complications did not increase in the postlegislation period (42 prelegislation vs 43 postlegislation; P = .514). Preoperative opioid use was the strongest predictor of opioid-refill demand (odds ratio, 4.19 [95% CI, 1.76-9.99]; P = .001). CONCLUSION: After the Ohio legislation was passed limiting opioid prescription, there was a significant reduction in opioids provided for patients undergoing ACLR. In spite of this decrease, no rebound increase in refill demands or postoperative pain-related complications were observed.

Opioid Requirement following Arthroscopic Knee Surgery: Are There Predictive Factors Associated with Long-Term Use.

The purpose of this study is to identify patterns of postoperative narcotic use and determine the impact of psychosocial and perioperative factors on postoperative opioid consumption following arthroscopic knee surgery. Fifty consecutive patients undergoing arthroscopic knee surgery were prospectively enrolled. Patients were contacted via telephone at 1 week postoperatively to report their pain level and opioid consumption. The patient was contacted again at 2 weeks, 4 weeks, and 90 days as necessary until opioid cessation, at which time the patient's plan for unused pills was inquired. Opioid consumption was compared using t-tests and one-way analysis of variance for demographic and surgical factors. Linear regression was used to determine whether the Pain Catastrophizing Scale (PCS), Resilience Scale (RS-11), International Knee Documentation Committee questionnaire, or patient-reported pain at 1 week predicted higher opioid consumption. The average morphine equivalent dose of opioid consumption was 142 mg. Sixty-four percent consumed less than 100 mg, and 68% discontinued opioid use by 1 week postoperatively. Seventy-four percent reported surplus pills, and 49% of those patients plans for pill disposal. Factors associated with higher consumption included undergoing a major procedure, having a regional anesthesia block, and higher area deprivation index score (p < 0.05). Higher PCS scores and reported average pain level at 1 week were predictive of higher opioid consumption (p < 0.05). In conclusion, a majority of patients undergoing outpatient knee surgery did not require the entirety of their narcotic prescription. The majority of patients consumed less than 100 mg of morphine equivalents and discontinued opioid use by 1 week postoperatively. Ligament reconstruction, living in an area with a higher index of deprivation, and higher score on the PCS were associated with greater opioid consumption. Overall, patient knowledge regarding opioid disposal was poor, and patients would likely benefit from additional education prior to surgery.

Staphylococcus lugdunensis Septic Arthritis following Arthroscopic Anterior Cruciate Ligament Reconstruction.

Summary. We report two cases of Staphylococcus lugdunensis (S. lugdunensis) septic arthritis following arthroscopic anterior cruciate ligament (ACL) reconstruction. Both initial surgical procedures were ACL reconstruction along with simultaneous collateral ligament and meniscus procedures. Patients presented with septic arthritis three and ten weeks following the index procedure. Both patients successfully recovered with early arthroscopic irrigation, debridement, and synovial culture, in addition to long-term parenteral and oral antibiotics.Staphylococcus lugdunensis (S. lugdunensis) septic arthritis following arthroscopic anterior cruciate ligament (ACL) reconstruction. Both initial surgical procedures were ACL reconstruction along with simultaneous collateral ligament and meniscus procedures. Patients presented with septic arthritis three and ten weeks following the index procedure. Both patients successfully recovered with early arthroscopic irrigation, debridement, and synovial culture, in addition to long-term parenteral and oral antibiotics.S. lugdunensis) septic arthritis following arthroscopic anterior cruciate ligament (ACL) reconstruction. Both initial surgical procedures were ACL reconstruction along with simultaneous collateral ligament and meniscus procedures. Patients presented with septic arthritis three and ten weeks following the index procedure. Both patients successfully recovered with early arthroscopic irrigation, debridement, and synovial culture, in addition to long-term parenteral and oral antibiotics.

American Football Players in Preseason Training at Risk of Acute Kidney Injury Without Signs of Rhabdomyolysis.

OBJECTIVE: This study was designed to identify changes in blood biomarkers that would indicate excessive muscle breakdown during the initial 10 days of preseason training in collegiate American football players and subsequently increase their risk of acute kidney injury (AKI). DESIGN: Prospective cohort study. SETTING: Preseason, heat acclimatization period. PARTICIPANTS: Twenty-five Division I American football players. INTERVENTION: Clinical biomarkers for muscle damage were measured during a preseason training camp. Samples were obtained before camp and approximately 5 and 10 days into camp after completion of heat acclimatization training. MAIN OUTCOMES: Creatine kinase, myoglobin, lactate dehydrogenase, and creatinine were measured. Glomerular filtration rate (GFR) was calculated. Urine was collected at each blood draw to qualitatively identify hematuria and red blood cells. RESULTS: A high percentage of athletes had an asymptomatic reduction in kidney function over the 10-day period. Ten of 23 athletes did have a significant, 31.6%, mean reduction in GFR, placing each at risk of AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification. The plasma myoglobin for the at risk of AKI group had a mean value 8× above their baseline mean on day 5 and statistically significant mean 13× higher on day 10 than baseline. The not at risk of AKI group did not have significant differences between days 0, 5, and 10. CONCLUSIONS: A relatively high percentage of athletes had an asymptomatic reduction in kidney function during the intense preseason training period. 43.4% of athletes in this study had a significant 31.6% mean reduction in GFR over the 10 days. According to RIFLE classification, this placed each athlete "at risk" of AKI.

Biomechanical and Functional Outcomes After Medial Patellofemoral Ligament Reconstruction: A Pilot Study.

BACKGROUND: Previous studies have acknowledged the medial patellofemoral ligament (MPFL) as the primary stabilizer of the patella, preventing lateral displacement. MPFL reconstruction (MPFL-R) restores stability and functionality to the patellofemoral joint and has emerged as a preferred treatment option for recurrent lateral patellar instability. PURPOSE: To objectively measure biomechanical characteristics of athletes cleared for return to sport after MPFL-R compared with healthy controls. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A prospective case-control study design was employed on 31 total athletes. Sixteen athletes (6 male, 10 female; mean age, 16.1 ± 2.74 years; 385 ± 189 days after surgery and 235 ± 157 days after return to sport) underwent MPFL-R and were medically cleared to return to sport. This group was matched by age, sex, and activity level to 15 healthy athletes with no history of lower extremity injuries. Athletes and controls completed validated questionnaires as well as hopping, jumping, and cutting tests with 3-dimensional motion analysis and underwent strength, flexibility, laxity, and balance assessments. RESULTS: Participants in the MPFL-R group scored significantly lower (worse) on the International Knee Documentation Committee (IKDC) (89.2 ± 7.6 vs 98.1 ± 2.0, respectively; P = .0005) and significantly higher (worse) on the Tampa Scale for Kinesiophobia (TSK) (32.4 ± 5.0 vs 25.4 ± 6.5, respectively; P = .006) than those in the control group, but there was no difference in the Kujala score (95.6 ± 5.3 vs 98.8 ± 3.0, respectively; P = .06). Participants in the MPFL-R group demonstrated reduced hip and ankle flexion relative to those in the control group (P < .05). Participants in the MPFL-R group also took significantly longer to complete the 6-m timed hop test relative to those in the control group (P < .05). No statistically significant differences were found in anthropometrics, knee extension or flexion strength, hamstring flexibility, hip abduction strength, or joint laxity between the MPFL-R and control groups. CONCLUSION: The current data indicate that MPFL-R generally restores functional symmetry, while subtle deficits in global power may remain after being released to full activity. Clinicians should ensure that athletes are fully rehabilitated before returning to sport after MPFL-R by emphasizing functional multijoint exercises.

Risk factors associated with ACL registry compliance: can we predict who will follow-up?

PURPOSE: The purpose of this study was to determine patient factors that influence patient compliance to fill out anterior cruciate ligament reconstruction (ACLR) registry forms. METHODS: Patients prospectively enrolled in the ACLR registry at a single institution were retrospectively reviewed. Patients who were followed up for at least 6 months were included. Patients who did not fill out initial registry forms were excluded. Patients were asked to fill out forms preoperatively and at 6, 12 and 24 months postoperatively. The impacts of age, race, employment status, medical insurance, smoking status, driving distance to the hospital and importance to return to the same level of sporting activity were analyzed against patient compliance (yes/no) to complete registry forms at the respective follow-ups. Multivariate analysis was performed to analyze variables at 6 and 12 months postoperatively. The numbers of patients who were followed up for more than 24 months were too low to run a multivariate analysis, so only univariate analysis was performed on this cohort. RESULTS: A total of 221 patients filled out the initial preoperative forms at least 6 months before data gathering was commenced and were included. At 6 months postoperatively, none of the variables significantly influenced patient compliance. At 12 months, younger age and longer driving distance to the hospital had a significant negative impact on compliance [OR per year: 0.92 (0.85-0.99), p = 0.0237; OR per mile: 1.01 (1, 1.01), p = 0.0297]. Patients who filled out registry forms at 6 months were significantly more compliant at 12 months postoperatively (p < 0.0001). At 24 months, the influence of age remained significant (p = 0.0262) and, additionally, patients who initially noted that it was important for them to return to the same level of sports were significantly less compliant (p = 0.0367). CONCLUSION: Younger age and longer driving distance to the hospital were significantly associated with less compliance to fill out ACLR registry forms at 12 months postoperatively. Patient perspectives on the importance to return to the same level of sports were inversely related to compliance at 24 months postoperatively. This information can be utilized to improve compliance in future studies as we have potentially identified patients that can be viewed as "at-risk" for registry noncompliance.

Anatomic Medial Patellofemoral Ligament Reconstruction Without Bone Tunnels or Anchors in the Patella.

Medial patellofemoral ligament reconstruction is an essential component of surgical treatment for recurrent dislocation of the patella. Various techniques have been described, most of which potentially increase the risk of patellar fracture. We present a new technique for anatomic medial patellofemoral ligament reconstruction without using suture anchors or patellar tunnels, therefore, eliminating the risk of iatrogenic patellar fracture and making a revision procedure easier in case of failure.

Underappreciated Factors to Consider in Revision Anterior Cruciate Ligament Reconstruction: A Current Concepts Review.

Primary anterior cruciate ligament (ACL) reconstructions (ACLRs) are being performed with increasing frequency. While many of these will have successful outcomes, failures will occur in a subset of patients who will require revision ACLRs. As such, the number of revision procedures will continue to rise as well. While many reviews have focused on factors that commonly contribute to failure of primary ACLR, including graft choice, patient factors, early return to sport, and technical errors, this review focused on several factors that have received less attention in the literature. These include posterior tibial slope, varus malalignment, injury to the anterolateral ligament, and meniscal injury or deficiency. This review also appraised several emerging techniques that may be useful in the context of revision ACL surgery. While outcomes of revision ACLR are generally inferior to those of primary procedures, identifying these potentially underappreciated contributing factors preoperatively will allow the surgeon to address them at the time of revision, ideally improving patient outcomes and preventing recurrent ACL failure.

Lack of eye discipline during headers in high school girls soccer: A possible mechanism for increased concussion rates.

The sport of soccer is the fastest growing and most popular sport worldwide. With this growth and popularity, attention needs to be given to this athletic population. Sports related concussions is a topic that has gained attention both in the media and by governmental organizations, with growing initiatives in diagnosis, prevention and treatment. The act of soccer heading is thought to contribute to increased concussion incidence. Current evidence reveals that within the high school soccer athletic population, female athletes incur a higher concussion rate than males. This is often attributed to many things including differing cervical spinal musculature, skull thickness, etc., but a definitive reason has not yet been found. Other behaviors, such as field awareness and eye discipline™ on the field of play, may also be contributing factors that result in females incurring a greater concussion rate than males. For the purposes of this paper we define eye discipline™ as the ability to keep the eyes engaged in sporting activity with high risk potential. We present our hypothesis that high school female soccer players are more likely to have their eyes closed when in position for heading the ball as compared to high school male soccer players and this lack of visual awareness may increase the risk of concussion. Should these differences be substantiated between males and females, it may initiate and promote discussion of the need for vision training in the high school athletic setting. As a tool for injury prevention, vision training may improve specific visual parameters improving athletes' abilities to process the field of play and prepare for or avoid injury causing situations. Through ocular motor and visual conditioning, an athlete may become more eye disciplined™, and more likely to have their eyes open during heading of the ball, and more likely to avoid concussions.

A Novel Mass-Spring-Damper Model Analysis to Identify Landing Deficits in Athletes Returning to Sport After Anterior Cruciate Ligament Reconstruction.

Schneider, DK, Gokeler, A, Otten, E, Ford, KR, Hewett, TE, Divine, JG, Colosimo, AJ, Heidt, RS, and Myer, GD. A Novel mass-spring-damper model analysis to identify landing deficits in athletes returning to sport after anterior cruciate ligament reconstruction. J Strength Cond Res 31(9): 2590-2598, 2017-A mass-spring-damper (MSD) model may serve as an extension of biomechanical data from 3-dimensional motion analysis and epidemiological data which helps to delineate populations at risk for anterior cruciate ligament (ACL) injuries. The purpose of this study was to evaluate such a model. Thirty-six ACL reconstruction (ACLR) group subjects and 67 controls (CTRL) completed single-leg drop landing and single-leg broad jump tasks. Landing ground reaction force data were collected and analyzed with an MSD model. Medians, interquartile ranges, and limb symmetry indices (LSIs) were calculated and comparisons were made within and between groups. During a single-leg drop landing, the ACLR group had a lower spring LSI than the CTRL group (p = 0.015) and landed with decreased stiffness in the involved limb relative to the uninvolved limb (p = 0.021). The ACLR group also had an increased damping LSI relative to the CTRL group (p = 0.045). The ACLR subjects landed with increased stiffness (p = 0.006) and decreased damping (p = 0.003) in their involved limbs compared to CTRL subjects' nondominant limbs. During a single-leg forward broad jump, the ACLR group had a greater spring LSI value than the CTRL group (p = 0.045). The CTRL group also recorded decreased damping values in their nondominant limbs compared with the involved limbs of the ACLR group (p = 0.046). Athletes who have undergone ACLR display different lower-limb dynamics than healthy controls, according to an MSD model. Quadriceps dominance and leg dominance are components of ACLR athletes' landing strategies and may be identified with an MSD model and addressed during rehabilitation.

Outcomes After Isolated Medial Patellofemoral Ligament Reconstruction for the Treatment of Recurrent Lateral Patellar Dislocations: A Systematic Review and Meta-analysis.

BACKGROUND: A patellar dislocation is a common knee injury in the young, athletic patient population. Recent trends indicate that the use of long-term nonoperative treatment is decreasing, and surgical intervention is more commonly recommended for those patients who fail initial nonoperative management with recurrent patellar dislocations. Medial patellofemoral ligament (MPFL) reconstruction has become increasingly utilized in this regard. PURPOSE: To evaluate outcomes, particularly return to sports and its relationship to postoperative instability, of isolated MPFL reconstruction for the treatment of recurrent patellar dislocations. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A review of the current literature was performed using the terms "medial patellofemoral ligament reconstruction" and "MPFL reconstruction" in the electronic search engines PubMed and EBSCOhost (CINAHL, MEDLINE, SPORTDiscus) on July 29, 2015, yielding 1113 abstracts for review. At the conclusion of the search, 14 articles met the inclusion criteria and were included in this review of the literature. Means were calculated for population size, age, follow-up time, and postoperative Tegner scores. Pooled estimates were calculated for postoperative Kujala scores, return to play, total risk of postoperative instability, risk of positive apprehension sign, and risk of reoperation. RESULTS: The mean patient age associated with MPFL reconstruction was 24.4 years, with a mean postoperative Tegner score of 5.7. The pooled estimated mean postoperative Kujala score was 85.8 (95% CI, 81.6-90.0), with 84.1% (95% CI, 71.1%-97.1%) of patients returning to sports after surgery. The pooled total risk of recurrent instability after surgery was 1.2% (95% CI, 0.3%-2.1%), with a positive apprehension sign risk of 3.6% (95% CI, 0%-7.2%) and a reoperation risk of 3.1% (95% CI, 1.1%-5.0%). CONCLUSION: A high percentage of young patients return to sports after isolated MPFL reconstruction for chronic patellar instability, with short-term results demonstrating a low incidence of recurrent instability, postoperative apprehension, and reoperations.

Vision training methods for sports concussion mitigation and management.

There is emerging evidence supporting the use vision training, including light board training tools, as a concussion baseline and neuro-diagnostic tool and potentially as a supportive component to concussion prevention strategies. This paper is focused on providing detailed methods for select vision training tools and reporting normative data for comparison when vision training is a part of a sports management program. The overall program includes standard vision training methods including tachistoscope, Brock's string, and strobe glasses, as well as specialized light board training algorithms. Stereopsis is measured as a means to monitor vision training affects. In addition, quantitative results for vision training methods as well as baseline and post-testing *A and Reaction Test measures with progressive scores are reported. Collegiate athletes consistently improve after six weeks of training in their stereopsis, *A and Reaction Test scores. When vision training is initiated as a team wide exercise, the incidence of concussion decreases in players who participate in training compared to players who do not receive the vision training. Vision training produces functional and performance changes that, when monitored, can be used to assess the success of the vision training and can be initiated as part of a sports medical intervention for concussion prevention.

Effects of postural control manipulation on visuomotor training performance: comparative data in healthy athletes.

PURPOSE/BACKGROUND: Visuomotor ability is an important parameter for neurologic function and effective sport performance. Adding a balance challenge during a structured eye-hand coordination task, such as hitting lights on a light board (Dynavision™), has not been previously reported. Using Division I football players, the aim of this study was to determine normative data on a dual-task performance regimen combining a visuomotor light board task with a balance task. The intent is to use such normative data and baseline data as part of a concussion management program. METHODS: Division I college football team members, n=105, were consented. Subjects first performed Dynavision™ D2™ Visuomotor Training Device (D2™) eye-hand coordination tasks, the A* and the RT; they then performed the same tasks with an added balance challenge, standing on a BOSU® ball. RESULTS: Ninety-four athletes completed the full testing procedure on the D2™ system. The mean score of the A* test was 93 ± 11.0 hits per minute; and the mean on the A* test with the added BOSU® balance challenge was 83.7 ± 9.2 hits per minute. The mean RT time was 0.33 ± 0.036 seconds. Mean reaction time increased to 0.38 ± 0.063 while the subject stood on the BOSU® ball. Performance on the D2™ A* and RT were both statistically significantly different in the dual task condition (p<0.05). CONCLUSIONS: Results show an approximate 10% decline in D2™ performance when healthy individuals stand on a BOSU® ball. From the data presented here, the authors determined that there is a 10% decrement in performance when one's balance is challenged on the BOSU® ball. A fall in performance of substantially greater than 10% may indicate abnormal vestibulocerebellar regulatory processing of balance and motion. Further research, using these normative data is needed to determine more specific parameters for definitions of impairment and return-to-play and if there is utility for such studies as part of a concussion management program. LEVEL OF EVIDENCE: III.

No association of time from surgery with functional deficits in athletes after anterior cruciate ligament reconstruction: evidence for objective return-to-sport criteria.

BACKGROUND: Release for full activity and return to sport after anterior cruciate ligament reconstruction (ACLR) is often dictated by time from surgery and subjective opinion by the medical team. Temporal guidelines for return to sport may not accurately identify impaired strength and neuromuscular control, which are associated with increased risk for second injury (contralateral and/or ipsilateral limb) after ACLR in athletes. HYPOTHESES: Athletes undergoing ACLR and returning to sport would demonstrate functional deficits that would not be associated with time from surgery. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-three male (n = 10) and female (n = 23) athletes with unilateral ACLR, who were cleared by a physician to return to their sport after surgery and rehabilitation, performed the single-legged vertical hop test for 10 seconds on a portable force plate. Matched teammates of each patient were recruited to serve as sex-, sport-, and age-matched controls (CTRL; n = 67). Maximum vertical ground-reaction force (VGRF) was measured during each single-limb landing. Single-limb symmetry index (LSI) was calculated as the ratio of the involved divided by uninvolved limb, expressed as a percentage. RESULTS: The single-limb vertical jump height LSI was reduced in the ACLR group, 89% (95% confidence interval [CI], 83%-95%), compared with the matched CTRL group, 101% (95% CI, 96%-105%; P < .01). The LSI for VGRF normalized to potential energy achieved during flight of the hop was increased in ACLR at 112% (95% CI, 106%-117%) relative to the CTRL group at 102% (95% CI, 98%-106%; P < .01). Linear regression analysis indicated that time from surgery was not associated with limb symmetry deficits in the ACLR group (P > .05; R (2) = .002-.01). CONCLUSION: Deficits in unilateral force development (vertical jump height) and absorption (normalized VGRF) persist in an athlete's single-limb performance after ACLR and full return to sports. These symmetry deficits appear to be independent of time after reconstruction. CLINICAL RELEVANCE: On the basis of these results, clinicians should consider assessment of single-limb power performance in the decision-making process for return-to-sport release. Persistent side-to-side asymmetries may increase the risk of contralateral and/or ipsilateral injury.