Karen Y. Peck

Duration of cognitive impairment after sports concussion.

OBJECTIVE:We sought to determine the duration of cognitive impairment after sports concussion. METHODS:We conducted a study with a prospective design in which 729 athletes underwent preseason baseline testing by being administered a computerized neuropsychological test battery, followed by retesting at regular intervals after they sustained sports-related concussions. A control group consisting of nonconcussed athletes drawn from the same baseline population underwent testing at parallel intervals. RESULTS:Cognitive impairment in this primarily American Academy of Neurology Grade II sample of boxing concussions was apparent on the day of injury and at 1 to 2 days postinjury. Recovery of cognitive performance occurred during the 3- to 7-day interval. Comparison with control subjects showed that absent or attenuated practice effects, in addition to frank deterioration from baseline, were indications of recent concussion. CONCLUSION:The present findings of recovery during the 3- to 7-day interval postinjury are consistent with the American Academy of Neurology Grade II return-to-play practice parameters suggesting a 1-week time-out from participation in contact sports.

Return to Play and Recurrent Instability After In-Season Anterior Shoulder Instability A Prospective Multicenter Study

Background: There is no consensus on the optimal treatment of in-season athletes with anterior shoulder instability, and limited data are available to guide return to play. Purpose: To examine the likelihood of return to sport and the recurrence of instability after an in-season anterior shoulder instability event based on the type of instability (subluxation vs dislocation). Additionally, injury factors and patient-reported outcome scores administered at the time of injury were evaluated to assess the predictability of eventual successful return to sport and time to return to sport during the competitive season. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: Over 2 academic years, 45 contact intercollegiate athletes were prospectively enrolled in a multicenter observational study to assess return to play after in-season anterior glenohumeral instability. Baseline data collection included shoulder injury characteristics and shoulder-specific patient-reported outcome scores at the time of injury. All athletes underwent an accelerated rehabilitation program without shoulder immobilization and were followed during their competitive season to assess the success of return to play and recurrent instability. Results: Thirty-three of 45 (73%) athletes returned to sport for either all or part of the season after a median 5 days lost from competition (interquartile range, 13). Twelve athletes (27%) successfully completed the season without recurrence. Twenty-one athletes (64%) returned to in-season play and had subsequent recurrent instability including 11 recurrent dislocations and 10 recurrent subluxations. Of the 33 athletes returning to in-season sport after an instability event, 67% (22/33) completed the season. Athletes with a subluxation were 5.3 times more likely (odds ratio [OR], 5.32; 95% CI, 1.00-28.07; P = .049) to return to sport during the same season when compared with those with dislocations. Logistic regression analysis suggests that the Western Ontario Shoulder Instability Index (OR, 1.05; 95% CI, 1.00-1.09; P = .037) and Simple Shoulder Test (OR, 1.03; 95% CI, 1.00-1.05; P = .044) administered after the initial instability event are predictive of the ability to return to play. Time loss from sport after a shoulder instability event was most strongly and inversely correlated with the Simple Shoulder Test (P = .007) at the time of initial injury. Conclusion: In the largest prospective study evaluating shoulder instability in in-season contact athletes, 27% of athletes returned to play and completed the season without subsequent instability. While the majority of athletes who return to sport complete the season, recurrent instability events are common regardless of whether the initial injury was a subluxation or dislocation.

Normative Values for the KOOS and WOMAC in a Young Athletic Population History of Knee Ligament Injury Is Associated With Lower Scores

Background: The use of patient-reported outcome measures to assess clinical outcomes after injury and surgery has become common in treating young athletes with orthopaedic injuries; however, normative data for these measures are limited and often include a wide range of ages and activity levels. Purpose: To provide normative data for the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in a young and athletic population, and to compare scores between participants with a history of knee ligament injury and those with no history. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We administered the KOOS and WOMAC to 1177 college freshmen entering the United States Military Academy in June 2011. All participants were healthy and had been medically screened to meet the physical induction standards for military service. We calculated means, standard deviations, percentiles, ranges, and interquartile ranges for the KOOS and WOMAC by sex and injury history. We also compared median scale scores for those with a history of knee ligament injury with those with no history using the Kruskal-Wallis test. Results: Among the 1177 participants, 971 were male (age, 18.8 ± 0.9 years), and the remaining 206 were female (age, 18.7 ± 0.8 years). Normative median values and interquartile ranges (IQRs) for the KOOS scale scores among men with no history of knee ligament injury were the following: Symptoms (96.4; IQR, 10.7), Pain (100; IQR, 2.8), Functional Activities of Daily Living (ADL) (100; IQR, 0.0), Sports and Recreation Function (100; IQR, 5.0), and Knee-Related Quality of Life (QOL) (100; IQR, 12.5). For women with no history of knee ligament injury, the KOOS scale scores were the following: Symptoms (92.9; IQR, 14.3), Pain (100; IQR, 5.6), Functional ADL (100; IQR, 2.9), Sports and Recreation Function (100; IQR, 10.0), and Knee-Related QOL (93.8; IQR, 18.8). Among the men, 139 (14%) reported a history of knee ligament injury, while 33 (16%) women also reported a history of injury. All KOOS scale scores and the WOMAC Stiffness and Function scale scores were significantly lower (P < .05) for men who reported a history of knee ligament injury. Similarly, Symptoms, Pain, and Knee-Related QOL on the KOOS and Pain on the WOMAC were significantly lower among women with a history of knee ligament injury. Conclusion: Normative values for all KOOS scales suggest a high level of functioning among participants with no history of knee ligament injury. Despite meeting the medical standards for military service, participants with a history of knee ligament injury had significantly lower KOOS and WOMAC scores upon entry to military service.

The Incidence of Injury Among Male and Female Intercollegiate Rugby Players

Background: The National Collegiate Athletic Association classifies women’s rugby as an emerging sport. Few studies have examined the injury rates in women’s collegiate rugby or compared injury rates between sexes. Hypothesis: Injury rates will differ between female and male intercollegiate club rugby players. Study Design: Descriptive epidemiological study. Methods: Five years of injury data were collected from the men’s and women’s rugby teams at a US service academy using the institution’s injury surveillance system. The primary outcome of interest was the incidence rate of injury during the study period per 10,000 athlete exposures. Incidence rate ratios (IRRs) were calculated using a Poisson distribution to compare the rates by sex. Results: During the study period, the overall incidence rate for injury was 30% higher (IRR = 1.30, 95% CI: 1.09, 1.54) among men when compared with women; however, the distribution of injuries varied by sex. The incidence rate for ACL injury among women was 5.3 times (IRR = 5.32, 95% CI: 1.33, 30.53) higher compared with that among men. Men were 2.5 times (IRR = 2.54, 95% CI: 1.03, 7.52) more likely to sustain a fracture. The rate of acromioclavicular joint injury was 2.2 times (IRR = 2.19, 95% CI: 1.03, 5.19) higher among men when compared with women. Men were 6.6 times (IRR = 6.55, 95% CI: 2.65, 20.91) more likely to have an open wound than women. Conclusion: There are differences in injury rates and patterns between female and male American rugby players. Clinical Relevance: The differences in injury patterns may reflect distinct playing styles, which could be the result of the American football background common among many of the male players.

Arthroscopic Versus Open Stabilization for Anterior Shoulder Subluxations

Background: Most of the literature on shoulder instability focuses on patients experiencing anterior glenohumeral dislocation, with little known about the treatment of anterior subluxation events. Purpose: To determine the outcomes of surgical stabilization of patients with anterior glenohumeral subluxations and to compare open and arthroscopic approaches. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: We prospectively enrolled patients with anterior glenohumeral subluxations undergoing surgical stabilization. Patients were offered randomization between open and arthroscopic stabilization. Inclusion criteria included patients with anterior glenohumeral subluxations undergoing Bankart repair, while exclusions included the presence of glenoid or humeral bone loss, multidirectional instability, capsular tear/humeral avulsion of the glenohumeral ligament lesion, and rotator cuff tear requiring repair. Patients were randomized to an open Bankart repair through a subscapularis takedown or an arthroscopic Bankart repair, both using the same bioabsorbable suture anchors, and they were followed for a minimum of 2 years. Outcomes were evaluated with the Single Assessment Numeric Evaluation (SANE), Western Ontario Shoulder Instability Index (WOSI), American Shoulder and Elbow Surgeons Score (ASES), Simple Shoulder Test (SST), Rowe, and Tegner activity scores. Results: A total of 26 patients were enrolled, with 7 being lost to follow-up. Complete follow-up data were available on 19 subjects (74%): 10 in the open group and 9 in the arthroscopic group. There were no significant differences noted between the randomized groups, with a 2-year WOSI score of 320 in the open subjects and 330 in the arthroscopic subjects, and similar findings in the other scoring scales. There were no cases of dislocation following surgery. There were 3 patients with recurrent instability (subluxations only) in each group at a mean of 17 months, for an overall recurrent subluxation rate of 31%. These subjects with recurrence had lower outcome scores (WOSI, 532; SANE, 88.4). The outcomes of the 9 subjects with ≤3 subluxation events were superior to those of the 10 subjects with >3 events prior to stabilization. The patients with ≤3 events had a WOSI score of 143, compared with 470 (P = .042), and an ASES mean score of 98.8, compared with 87.1 (P = .048). Four of the 6 patients with recurrent subluxations had sustained >3 subluxations prior to stabilization. Conclusion: Overall, patients with Bankart lesions resulting from an anterior glenohumeral subluxation event had excellent outcomes with surgical stabilization. The overall recurrence in the 19 subjects with at least 2-year follow-up was 6 cases (31%), with no instances of dislocation in this young, active cohort. There was no significant benefit to open or arthroscopic stabilization, and we did find that stabilization of subluxation patients with ≤3 events resulted in superior outcomes compared with chronic recurrent subluxation patients with >3 events. We recommend early surgical stabilization of young athletes with Bankart lesions that result from anterior subluxation events.

The Effects of an Injury Prevention Program on Landing Biomechanics Over Time

Background: Knowledge is limited regarding how long improvements in biomechanics remain after completion of a lower extremity injury prevention program. Purpose: To evaluate the effects of an injury prevention program on movement technique and peak vertical ground-reaction forces (VGRF) over time compared with a standard warm-up (SWU) program. Study Design: Controlled laboratory study. Methods: A total of 1104 incoming freshmen (age range, 17-22 years) at a military academy in the United States volunteered to participate. Participants were cluster-randomized by military company to either the Dynamic Integrated Movement Enhancement (DIME) injury prevention program or SWU. A random subsample of participants completed a standardized jump-landing task at each time point: immediately before the intervention (PRE), immediately after (POST), and 2 (POST2M), 4 (POST4M), 6 (POST6M), and 8 months (POST8M) after the intervention. VGRF data collected during the jump-landing task were normalized to body weight (%BW). The Landing Error Scoring System (LESS) was used to evaluate movement technique during the jump landing. The change scores (Δ) for each variable (LESS, VGRF) between the group’s average value at PRE and each time point were calculated. Separate univariate analyses of variance were performed to evaluate group differences. Results: The results showed a greater decrease in mean (±SD) VGRF in the DIME group compared with the SWU group at all retention time points: POST2M (SWU [Δ%BW], −0.13 ± 0.82; DIME, −0.62 ± 0.91; P = .001), POST4M (SWU, −0.15 ± 0.98; DIME,−0.46 ± 0.64; P = .04), POST6M (SWU, −0.04 ± 0.96; DIME, −0.53 ± 0.83; P = .004), and POST8M (SWU, 0.38 ± 0.95; DIME, −0.11 ± 0.98; P = .003), but there was not a significant improvement in the DIME group between PRE and POST8M (Δ%BW, −0.11 ± 0.98). No group differences in Δ LESS were observed. Conclusion: The study findings demonstrated that an injury prevention program performed as a warm-up can reduce vertical ground-reaction forces compared with a standard warm-up but a maintenance program is likely necessary in order for continued benefit. Clinical Relevance: Injury prevention programs may need to be performed constantly, or at least every sport season, in order for participants to maintain the protective effects against injury.

The Effect of Subcritical Bone Loss and Exposure on Recurrent Instability After Arthroscopic Bankart Repair in Intercollegiate American Football

Background: There is no consensus on the optimal method of stabilization (arthroscopic or open) in collision athletes with anterior shoulder instability. Purpose: To examine the effect of “subcritical” bone loss and football-specific exposure on the rate of recurrent shoulder instability after arthroscopic stabilization in an intercollegiate American football population. Study Design: Case-control study; Level of evidence, 3. Methods: Fifty intercollegiate football players underwent primary arthroscopic stabilization for anterior shoulder instability and returned to football for at least a single season. Preoperatively, 32 patients experienced recurrent subluxations, and 18 patients experienced a single or recurrent dislocation. Shoulders with glenoid bone loss >20%, an engaging Hill-Sachs lesion, an off-track lesion, and concomitant rotator cuff repair were excluded from the study. The primary outcome of interest was the ability to return to football without subsequent instability. Patients were followed for time to a subsequent instability event after return to play using days of exposure to football and total follow-up time after arthroscopic stabilization. Results: Fifty consecutive patients returned to American football for a mean 1.5 seasons (range, 1-3) after arthroscopic stabilization. Three of 50 (6%; 95% CI, 1.3%-16.5%) patients experienced recurrent instability. There were no subsequent instability events after a mean 3.2 years of military service. All shoulders with glenoid bone loss >13.5% (n = 3) that underwent arthroscopic stabilization experienced recurrent instability upon returning to sport, while none of the shoulders with <13.5% glenoid bone loss (n = 47) sustained a recurrent instability event during football (X2 = 15.80, P < .001). Shoulders with >13.5% glenoid bone loss had an incidence rate of 5.31 cases of recurrent instability per 1000 athlete-exposures of football. In 72,000 athlete-exposures to football with <13.5% glenoid bone loss, there was no recurrent instability. Significantly more anchors were used during the primary arthroscopic stabilization procedure in patients who experienced multiple preoperative instability events (P = .005), and lesions spanned significantly more extensive portions along the circumference of the glenoid (P = .001) compared with shoulders having a single preoperative instability event before surgical stabilization. Conclusion: Arthroscopic stabilization of anterior shoulder instability in American football players with <13.5% glenoid bone loss provides reliable outcomes and low recurrence rates.

Biomechanical Risk Factors for Lower Extremity Stress Fracture.

Objectives: Stress fracture injuries disproportionately affect athletes and military service members and little is known about the modifiable biomechanical risk factors associated with these injuries. The purpose of this study was to prospectively examine the association between neuromuscular and biomechanical factors upon entry to military service and the subsequent incidence of lower-extremity stress fracture injury during four years of follow-up. Methods: We analyzed data from the JUMP-ACL cohort, an existing prospective cohort study of military cadets. JUMP-ACL conducted detailed motion analysis during a jump landing task at the initiation of each subject’s military career. We limited our analyses to the class years 2009-2013 (i.e., subjects who completed baseline testing in 2005-2008). There were 1895 subjects available for analysis. Fifty-two subjects reported a history of stress fracture at baseline and were excluded from further analysis leaving 1843 subjects. Incident lower extremity-stress fracture cases were identified through the Defense Medical Surveillance System and the Cadet Injury and Illness Tracking System during the follow-up period. The electronic medical records of each potential incident case were reviewed and each case was confirmed by an adjudication committee consisting of two sports medicine fellowship trained orthopaedic surgeons. The primary outcome of interest was the incidence rate of lower-extremity stress fracture during the follow-up period. The association between incident stress fracture and sagittal, frontal, and transverse plane hip and knee kinematics during the jump-landing task were examined at initial contact (IC), 15%(T15), 50%(T50), 85%(T85) and 100%(T100) of stance phase. Descriptive plots of all biomechanical variables along with 95% confidence intervals (CI) were generated during the stance phase of the jump landing task. Univariate and multivariable Poisson regression models were used to estimate the association between baseline biomechanical factors and the incidence rate of lower-extremity stress fracture during follow-up. Results: Overall, 94 (5.1%, 95%CI: 4.14, 6.21) subjects sustained an incident stress fracture during the follow-up period. The incidence rate for stress fracture injuries among females was nearly three times greater when compared to males (IRR=2.86, 95%CI: 1.88, 4.34, p<0.001). Compared to those with greater than 5° of knee valgus, subjects with neutral or varus knee alignment experienced incidence rates for stress fracture that were 43%-53% lower at IC (IRR=0.57, 95%CI: 0.29, 1.11, p=0.10), T50 (IRR=0.47, 95%CI=0.23, 1.00, p=0.05), and T85 (IRR=0.53, 95%CI: 0.29, 0.98, p=0.04). Subjects with greater than 5° of internal knee rotation exhibited rates for stress fracture that were 2-4 times higher at T15 (IRR=2.31, 95%CI: 1.01, 5.27, p=0.05), T50 (IRR=3.98, 95%CI: 0.99, 16.00, p=0.05), and T85 (IRR=2.31, 95%CI: 0.86, 6.23, p=0.10), when compared to those with neutral or external knee rotation alignment. Conclusion: Several potentially modifiable biomechanical factors at the time of entry into military service appear to be associated with the subsequent rate of stress fracture. It is possible that injury prevention programs targeted to address these biomechanical movement patterns may reduce the risk of stress fracture injury in athletes and military service members.

Successful Return to Sport After Arthroscopic Shoulder Stabilization Versus Nonoperative Management in Contact Athletes With Anterior Shoulder Instability: A Prospective Multicenter Study:

Background: The debate continues regarding the optimal treatment of intercollegiate contact athletes with in-season anterior shoulder instability. Purpose: To examine return to sport and recurrent instability in the season after the index in-season anterior instability event. Study Design: Cohort study; Level of evidence, 2. Methods: Forty-five contact intercollegiate athletes treated nonoperatively or with arthroscopic stabilization were prospectively followed in a multicenter observational study to evaluate return to play (RTP) and recurrent instability in the season after an initial in-season anterior glenohumeral instability event. Baseline data collection included sport played, previous instability events, direction of instability, type of instability (subluxation or dislocation), and treatment method (nonoperative management or arthroscopic stabilization). All nonoperatively treated athletes underwent a standardized accelerated rehabilitation program without shoulder immobilization. Surgical stabilization was performed arthroscopically in all cases, and successful RTP was evaluated during the next competitive season after complete rehabilitation. Results: Thirty-nine of 45 intercollegiate contact athletes had remaining National Collegiate Athletic Association eligibility and were followed through the subsequent competitive season after the index instability event. Of the 10 athletes electing nonoperative treatment, 4 (40%) successfully returned to play without recurrence during the subsequent season. Of the 29 athletes treated surgically, 26 (90%) were able to successfully return to play without recurrence the following season (recurrence: n = 1; inadequate function: n = 2). Athletes who underwent surgical reconstruction before the next season were 5.8 times (95% CI, 1.77-18.97; P = .004) more likely to complete the subsequent season without recurrent instability. Of the 29 athletes electing surgical stabilization, there was no difference (risk ratio, 0.95; 95% CI, 0.10-9.24; P > .99) in RTP between the 9 stabilized after a single instability event (90% RTP rate) and the 20 stabilized after multiple in-season recurrent instability events (89% RTP rate). Conclusion: Collegiate contact and collision athletes with in-season anterior shoulder instability are significantly more likely to successfully return to sport without subsequent instability events the next season if they undergo surgical repair in the off-season.

Reference Values for the Marx Activity Rating Scale in a Young Athletic Population History of Knee Ligament Injury Is Associated With Higher Scores

Background: Activity-related patient-reported outcome measures are an important component of assessment after knee ligament injury in young and physically active patients; however, normative data for most activity scales are limited. Objective: To present reference values by sex for the Marx Activity Rating Scale (MARS) within a young and physically active population while accounting for knee ligament injury history and sex. Study Design: Cross-sectional study. Level of Evidence: Level 2. Methods: All incoming freshman entering a US Service Academy in June of 2011 were recruited to participate in this study. MARS was administered to 1169 incoming freshmen (203 women) who consented to participate within the first week of matriculation. All subjects were deemed healthy and medically fit for military service on admission. Subjects also completed a baseline questionnaire that asked for basic demographic information and injury history. We calculated means with standard deviations, medians with interquartile ranges, and percentiles for ordinal and continuous variables, and frequencies and proportions for dichotomous variables. We also compared median scores by sex and history of knee ligament injury using the Kruskal-Wallis test. MARS was the primary outcome of interest. Results: The median MARS score was significantly higher for men when compared with women (χ2 = 13.22, df = 1, P < 0.001) with no prior history of knee ligament injury. In contrast, there was no significant difference in median MARS scores between men and women (χ2 = 0.47, df = 1, P = 0.493) who reported a history of injury. Overall, median MARS scores were significantly higher among those who reported a history of knee ligament injury when compared with those who did not (χ2 = 9.06, df = 1, P = 0.003). Conclusion: Assessing activity as a patient-reported outcome after knee ligament injury is important, and reference values for these instruments need to account for the influence of prior injury and sex.