Psychological Factors Are Related to Neuromuscular Asymmetries After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: After an anterior cruciate ligament reconstruction (ACLR), only 47% of military members return to full duty, possibly due to persistent neuromuscular asymmetries. Psychological factors may also contribute to reduced return to duty in military members. HYPOTHESIS: Psychological factors and time since surgery would be associated negatively with neuromuscular asymmetries, asymmetries would be greater in cadets postsurgery when compared with healthy controls, and asymmetries would be greater at earlier timepoints after ACLR. STUDY DESIGN: Case control. LEVEL OF EVIDENCE: Level 4. METHODS: This study examined the relationship between psychological factors and time since surgery with neuromuscular asymmetry, compared neuromuscular asymmetries between cadets with and without a history of ACLR, and explored differences in neuromuscular asymmetries at different timepoints in cadets with a history of ACLR. A total of 37 cadets post-ACLR (18.3 ± 9 months) and 28 controls participated. Psychological factors were assessed using the Tampa Scale of Kinesiophobia and Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI). Participants performed a drop-jump landing, joint positioning sense (JPS), and isometric quadriceps strength testing. Peak vertical ground-reaction forces (vGRF), absolute angle of replication, peak quadriceps torque, rate of torque development (RTD), and RTD time torque interval 200 ms (TTI200) were analyzed. RESULTS: The ACL-RSI score was significantly related to limb symmetry index (LSI) peak quadriceps torque (r = 0.617, P < 0.01), LSI RTD (r = 0.367, P = 0.05), and LSI TTI200 (r = 0.0489, P < 0.01), but not time since surgery, JPS, or LSI peak vGRF. Cadets with a history of ACLR had significantly lesser ACL-RSI scores and greater asymmetries compared with controls. CONCLUSION: Reduced psychological readiness was associated with increased neuromuscular asymmetries after ACLR. CLINICAL RELEVANCE: Clinicians should assess psychological readiness during rehabilitation after ACLR.

Timing of Outcomes and Expectations After Knee Surgery in the US Military: A Systematic Review.

CONTEXT: Knee injury and subsequent surgery are widespread in the military setting. Associations between knee surgery and expected outcomes over time have not been consolidated and characterized systematically by procedure type across the body of literature, and the temporal expectations of these outcomes remain unclear. OBJECTIVE: To summarize common postoperative follow-up times and associated outcomes that determine clinical or surgical failure in US service members after elective knee surgery. DATA SOURCES: A systematic search was conducted with 3 bibliographic databases of published research reports from 2010 through 2021. STUDY SELECTION: Studies in US military service members undergoing elective knee surgery, with a minimum of 1-year follow-up, and reporting on a functional/occupational outcome were included. Three reviewers screened all abstracts and full-text articles to determine eligibility. STUDY DESIGN: Systematic review of longitudinal cohort studies. LEVEL OF EVIDENCE: Level 2a. DATA EXTRACTION: Extracted data included military demographics, surgical procedure variables, surveillance period, and outcome measures. The Newcastle-Ottawa Scale and the Grading of Recommendations Assessment, Development, and Evaluation approach were used to determine study quality and risk of bias. RESULTS: A total of 22 studies (mean follow-up time of 40.7 months) met the inclusion criteria. For cruciate ligament repair, approximately one-third of patients required a second surgery or were medically separated from military service by 2 years from surgery; 100% were reinjured by 4 years, and 85% sustained a new injury within 5 years of surgery. For meniscal repair, nearly one-third of patients were medically separated, and half were placed on activity restrictions within 3 years of surgery. For articular cartilage repair, within 5 years, 39% of patients required a second surgery, 30% were placed on activity restrictions, and 36% were medically separated. For patellar repair, 37% of patients were medically separated and over half were placed on activity restrictions within 5 years. CONCLUSION: Common knee surgeries can have long-term implications for military careers that may not become apparent with shorter follow-up periods (<2 years). When longer surveillance periods are used (eg, up to 5 years), additional surgical procedures are more common and the likelihood of being injured or medically separated from military service is higher.

Beach-Chair Versus Lateral Decubitus Positioning for Primary Arthroscopic Anterior Shoulder Stabilization: A Consecutive Series of 641 Shoulders.

BACKGROUND: There are limited data comparing the beach-chair (BC) versus lateral decubitus (LD) position for arthroscopic anterior shoulder stabilization. PURPOSE: To identify predictors of instability recurrence and revision after anterior shoulder stabilization and evaluate surgical position and glenoid bone loss as independent predictors of recurrence and revision at short- and midterm follow-ups. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A consecutive series of 641 arthroscopic anterior stabilization procedures were performed from 2005 to 2019. All shoulders were evaluated for glenohumeral bone loss on magnetic resonance imaging. The primary outcomes of interest were recurrence and revision. Multivariable logistic regression models were used to assess the relationships of outcomes with age, position, glenoid bone loss group, and track. RESULTS: A total of 641 shoulders with a mean age of 22.3 years (SD, 4.45 years) underwent stabilization and were followed for a mean of 6 years. The overall 1-year recurrent instability rate was 3.3% (21/641) and the revision rate was 2.8% (18/641). At 1 year, recurrence was observed in 2.3% (11/487) and 6.5% (10/154) of BC and LD shoulders, respectively. The 5-year recurrence and revision rates were 15.7% (60/383) and 12.8% (49/383), respectively. At 5 years, recurrence was observed in 16.4% (48/293) and 13.3% (12/90) of BC and LD shoulders, respectively. Multivariable modeling demonstrated that surgical position was not associated with a risk of recurrence after 1 year (odds ratio [OR] for LD vs BC, 1.39; P = .56) and 5 years (OR for LD vs BC, 1.32; P = .43), although younger age at index surgery was associated with a higher risk of instability recurrence (OR, 1.73 per SD [4.1 years] decrease in age; P < .03). After 1 and 5 years, surgical position results were similar in a separate multivariable logistic regression model of revision surgery as the dependent variable, when adjusted for age, surgical position, bone loss group, and track. At 5 years, younger age was an independent risk factor for revision: OR 1.68 per SD (4.1 years) decrease in age (P < .05). CONCLUSION: Among fellowship-trained orthopaedic surgeons, there was no difference in rates of recurrence and revision surgery after performing arthroscopic anterior stabilization in either the BC or the LD position at 1- and 5-year follow-ups. In multivariable analysis, younger age, but not surgical position, was an independent risk factor for recurrence.

Predicting Postoperative Injury and Military Discharge Status After Knee Surgery in the US Army.

BACKGROUND: Researchers have assessed postoperative injury or disability predictors in the military setting but typically focused on 1 type of surgical procedure at a time, used relatively small sample sizes, or investigated mixed cohorts with civilian populations. PURPOSE: To identify the relationship between baseline variables and injury incidence or military discharge status in US Army soldiers after knee surgery. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Data were obtained from a repository containing personnel, performance, and medical records for all active-duty US Army soldiers. Multivariate logistic regressions were used to estimate the effects of numerous variables on postoperative injury or on medical discharge. Variable selection and model validation were conducted using the k-fold method. RESULTS: A total of 7567 soldiers underwent knee surgery between 2017 and 2019. Meniscal procedures were the most common type of surgery (39%), and approximately 71% of the cohort had a postoperative injury. Significant predictors for sustaining a postoperative injury included having a previous nonknee injury (odds ratio [OR], 1.5), female sex (OR, 1.3), and Black race (OR, 1.2). Within 4 years after surgery, 17% of soldiers were discharged from the military because of knee-related disability. Significant predictors for discharge from duty included enlisted rank (OR, 2.3), recent fitness test failure (OR, 1.9), number of previous knee surgeries (OR, 1.7), and having a previous nonknee injury (OR, 1.6). CONCLUSION: After knee surgery, nearly three-fourths of the soldiers in this cohort sustained a postoperative injury and almost one-fifth of soldiers were medically discharged from the military within 4 years. This study identified variables that indicate statistically increased risk for these postoperative outcomes and highlighted potentially modifiable factors.

Revision Arthroscopic Bankart Repair Results in High Failure Rates and a Low Return to Duty Rate Without Recurrent Instability.

PURPOSE: The purpose of this study was to determine, in a military population without critical bone loss, the rate of recurrent instability after revision arthroscopic stabilization for failed primary arthroscopic Bankart repair. METHODS: Forty-one revision arthroscopic stabilizations were performed at a single military institution between 2005 to 2016 for recurrent anterior shoulder instability after primary arthroscopic Bankart repair. Minimum follow-up was 2 years, and shoulders with glenoid bone loss >20% were excluded. The primary outcome of interest was the incidence of failure, defined by recurrent instability. RESULTS: Age at revision surgery averaged 22.9 ± 4.3 years, and 88% were either service academy cadets or active duty combat arms soldiers. Mean follow-up was 7.8 years. Twenty-three patients (56%) returned to duty without recurrent instability after revision arthroscopic stabilization. Eighteen patients (44%) experienced recurrent instability after return to duty. Glenoid bone loss averaged 6.2% (95% confidence interval [CI], 3.2%-9.2%) in the successful group and 5.7% (95% CI, 3.1%-8.3%) in the failure group (P = .808). CONCLUSIONS: Revision arthroscopic stabilization of failed primary arthroscopic Bankart repair has a failure rate of 44% in a young military population. The similar amounts of bone loss between groups indicates that bone loss is not the primary determinant of failure in revision arthroscopic stabilization. LEVEL OF EVIDENCE: IV, Case Series.

Influence of Graft Type on Lower Extremity Functional Test Performance and Failure Rate After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population. OBJECTIVE: To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)]. STUDY DESIGN: Cross-sectional. LEVEL OF EVIDENCE: Level 2. METHODS: Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures. RESULTS: Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB (P = 0.045). CONCLUSION: After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure. CLINICAL RELEVANCE: Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure.

Prospective Evaluation of Posterior Glenoid Bone Loss After First-time and Recurrent Posterior Glenohumeral Instability Events.

BACKGROUND: Although posterior glenohumeral instability is becoming an increasingly recognized cause of shoulder pain, the role of posterior glenoid bone loss on outcomes remains incompletely understood. PURPOSES: To prospectively determine the amount of bone loss associated with posterior instability events and to determine predisposing factors based on preinstability imaging. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 1428 shoulders were evaluated prospectively for ≥4 years. At baseline, a subjective history of shoulder instability was ascertained for each patient, and bilateral noncontrast magnetic resonance imaging (MRI) scans of the shoulders were obtained regardless of any reported history of shoulder instability. The cohort was prospectively followed during the study period, and those who were diagnosed with posterior glenohumeral instability were identified. Postinjury MRI scans were obtained and compared with the screening MRI scans. Glenoid version, perfect-circle-based bone loss was measured for each patient's pre- and postinjury MRI scans using previously described methods. RESULTS: Of the 1428 shoulders that were prospectively followed, 10 shoulders sustained a first-time posterior instability event and 3 shoulders sustained a recurrent posterior instability event. At baseline, 11 of 13 shoulders had some amount of glenoid dysplasia and/or bone loss. The change in glenoid bone loss was 5.4% along the axis of greatest loss (95% CI, 3.8%-7.0%; P = .009), 4.4% at the glenoid equator (95% CI, 2.7%-6.2%; P = .016), and 4.2% of total glenoid area (95% CI, 2.9%-5.3%; P = .002). Recurrent glenoid instability was associated with a greater amount of absolute bone loss along the axis of greatest loss compared with first-time instability (recurrent: 16.8% ± 1.1%; 95% CI, 14.6%-18.9%; first-time: 10.0% ± 1.5%; 95% CI, 7.0%-13.0%; P = .005). Baseline glenoid retroversion ≥10° was associated with a significantly greater percentage of bone loss along the axis of greatest loss (≥10° of retroversion: 13.5% ± 2.0%; 95% CI, 9.6%-17.4%; <10° of retroversion: 8.5% ± 0.8%; 95% CI, 7.0%-10.0%; P = .045). CONCLUSIONS: Posterior glenohumeral instability events were associated with glenoid bone loss of 5%. The amount of glenoid bone loss after a recurrent posterior glenohumeral instability event was greater than that after first-time instability. Glenoid retroversion ≥10° was associated with a greater amount of posterior glenoid bone loss after a posterior instability event.

Concomitant Glenohumeral Instability and Rotator Cuff Injury: An Epidemiologic and Case-Control Analysis in Military Cadets.

INTRODUCTION: Concomitant rotator cuff tear and glenohumeral instability in a large cohort of young and active patients has not been examined. The purpose of this study was to investigate the incidence, associated variables, and outcomes in military cadets undergoing shoulder stabilization procedures with these concomitant pathologies. METHODS: A retrospective cohort study of a consecutive series of collegiate patients who underwent shoulder stabilization from 2014 to 2018 at a single service academy was conducted. Exclusion criteria were noncadets, revision instability cases, multidirectional instability, and prior rotator cuff repair. A nested case-control analysis was done in a matched series of patients with and without MRI evidence of rotator cuff tear. Baseline demographics, VAS pain scale, physical therapy duration, and time to surgery were analyzed. Postoperative metrics included rate of recurrent instability, subjective outcomes, VAS pain scale, and military-specific criteria. RESULTS: Three hundred twenty-four cadets met the inclusion criteria, including 272 men and 52 women averaging 20.53 ± 1.80 years of age. MRI demonstrated concomitant rotator cuff tears in 5.56% of cases. A matched case-control comparison between patients with (rotator cuff tear group) and without (no rotator cuff tear group) rotator cuff tear showed no differences in preoperative data, recurrent instability rate, or postoperative VAS pain scores (0.24 versus 0.88, P = 0.207) at mean 44-month follow-up. Fifteen of 17 patients (88.2%) in each group returned to full activity (P > 0.999). No patients failed to graduate due to shoulder concerns. No patients in the rotator cuff tear group underwent a medical board for separation from the military compared with 2 (11.8%) in the no rotator cuff tear group (P = 0.163). CONCLUSIONS: The incidence of concomitant rotator cuff tears in this study of military cadets undergoing shoulder stabilization was 5.56%. In a matched cohort comparison, the presence of a rotator cuff tear on preoperative MRI was not associated with inferior clinical outcomes.

The Military Orthopedics Tracking Injuries and Outcomes Network: A Solution for Improving Musculoskeletal Care in the Military Health System.

INTRODUCTION: Musculoskeletal injuries are an endemic amongst U.S. Military Service Members and significantly strain the Department of Defense's Military Health System. The Military Health System aims to provide Service Members, military retirees, and their families the right care at the right time. The Military Orthopedics Tracking Injuries and Outcomes Network (MOTION) captures the data that can optimize musculoskeletal care within the Military Health System. This report provides MOTION structural framework and highlights how it can be used to optimize musculoskeletal care. MATERIALS AND METHODS: MOTION established an internet-based data capture system, the MOTION Musculoskeletal Data Portal. All adult Military Health System patients who undergo orthopedic surgery are eligible for entry into the database. All data are collected as routine standard of care, with patients and orthopedic surgeons inputting validated global and condition-specific patient reported outcomes and operative case data, respectively. Patients have the option to consent to allow their standard of care data to be utilized within an institutional review board approved observational research study. MOTION data can be merged with other existing data systems (e.g., electronic medical record) to develop a comprehensive dataset of relevant information. In pursuit of enhancing musculoskeletal injury patient outcomes MOTION aims to: (1) identify factors which predict favorable outcomes; (2) develop models which inform the surgeon and military commanders if patients are behind, on, or ahead of schedule for their targeted return-to-duty/activity; and (3) develop predictive models to better inform patients and surgeons of the likelihood of a positive outcome for various treatment options to enhance patient counseling and expectation management. RESULTS: This is a protocol article describing the intent and methodology for MOTION; thus, to date, there are no results to report. CONCLUSIONS: MOTION was established to capture the data that are necessary to improve military medical readiness and optimize medical resource utilization through the systematic evaluation of short- and long-term musculoskeletal injury patient outcomes. The systematic enhancement of musculoskeletal injury care through data analyses aligns with the National Defense Authorization Act (2017) and Defense Health Agency's Quadruple Aim, which emphasizes optimizing healthcare delivery and Service Member medical readiness. This transformative approach to musculoskeletal care can be applied across disciplines within the Military Health System.

A High-Sensitivity International Knee Documentation Committee Survey Index From the PROMIS System: The Next-Generation Patient-Reported Outcome for a Knee Injury Population.

BACKGROUND: Patient-reported outcomes (PROs) measure progression and quality of care. While legacy PROs such as the International Knee Documentation Committee (IKDC) survey are well-validated, a lengthy PRO creates a time burden on patients, decreasing adherence. In recent years, PROs such as the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function and Pain Interference surveys were developed as computer adaptive tests, reducing time to completion. Previous studies have examined correlation between legacy PROs and PROMIS; however, no studies have developed effective prediction models utilizing PROMIS to create an IKDC index. While the IKDC is the standard knee PRO, computer adaptive PROs offer numerous practical advantages. PURPOSE: To develop a nonlinear predictive model utilizing PROMIS Physical Function and Pain Interference to estimate IKDC survey scores and examine algorithm sensitivity and validity. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: The MOTION (Military Orthopaedics Tracking Injuries and Outcomes Network) database is a prospectively collected repository of PROs and intraoperative variables. Patients undergoing knee surgery completed the IKDC and PROMIS surveys at varying time points. Nonlinear multivariable predictive models using Gaussian and beta distributions were created to establish an IKDC index score, which was then validated using leave-one-out techniques and minimal clinically important difference analysis. RESULTS: A total of 1011 patients completed the IKDC and PROMIS Physical Function and Pain Interference, providing 1618 complete observations. The algorithms for the Gaussian and beta distribution were validated to predict the IKDC (Pearson = 0.84-0.86; R2 = 0.71-0.74; root mean square error = 9.3-10.0). CONCLUSION: The publicly available predictive models can approximate the IKDC score. The results can be used to compare PROMIS Physical Function and Pain Interference against historical IKDC scores by creating an IKDC index score. Serial use of the IKDC index allows for a lower minimal clinically important difference than the conventional IKDC. PROMIS can be substituted to reduce patient burden, increase completion rates, and produce orthopaedic-specific survey analogs.

The Epidemiology of Meniscus Injury.

Meniscus surgery is one of the most commonly performed orthopedic procedures worldwide. Modifiable risk factors for meniscus injury include body mass index, participation in athletics and occupation. Nonmodifiable risk factors include age, sex, lower extremity alignment, discoid meniscus, ligamentous laxity, and biconcave tibial plateau. Conditions commonly associated with meniscal injury are osteoarthritis, anterior cruciate ligament injury, and tibial plateau fractures. Tear type and location vary by patient age and functional status. Surgical management of meniscus injury is typically cost-effective in terms of quality-adjusted life years. The purpose of this review is to provide an overview of meniscal injury epidemiology by summarizing tear types and locations, associated conditions, and factors that increase the risk for meniscal injury. The economic burden of meniscus injury and strategies to prevent injury to the meniscus are also reviewed.

Recurrent Instability and Surgery Are Common After Nonoperative Treatment of Posterior Glenohumeral Instability in NCAA Division I FBS Football Players.

BACKGROUND: In-season return to play after anterior glenohumeral instability is associated with high rates of recurrent instability and the need for surgical stabilization. We are not aware of previous studies that have investigated in-season return to play after posterior glenohumeral instability; furthermore, as posterior shoulder instability in collision athletes occurs frequently, understanding the expected outcome of in-season athletes may improve the ability of physicians to provide athletes with a better understanding of the expected outcome of their injury and their ability to return to sport. QUESTIONS/PURPOSES: (1) What proportion of athletes returned to play during the season after posterior instability in collegiate football players? (2) How much time did athletes lose to injury, what proportion of athletes opted to undergo surgery, and what proportion of athletes experienced recurrent instability after a posterior instability episode during a collegiate football season? METHODS: A multicenter, prospective, observational study of National Collegiate Athletic Association (NCAA) Division 1 Football Bowl Subdivision athletes was performed at three US Military Service Academies. Ten athletes who sustained a posterior instability event during the regular football season and who pursued a course of nonoperative treatment were identified and prospectively observed through the subsequent season. All athletes in the observed cohort attempted an initial course of nonoperative treatment during the season. All athletes sustained subluxation events initially identified through history and physical examination at the time of injury. None of the athletes sustained a dislocation event requiring a manual reduction. Intraarticular pathology consisting of posterior labral pathology was further subsequently identified in all subjects via MRI arthrogram. Return to play was the primary outcome of interest. Time lost to injury, surgical intervention, and subsequent instability were secondary outcomes. RESULTS: Of the 10 athletes who opted for a trial of initial nonoperative management, seven athletes were able to return to play during the same season. Although these seven athletes returned within 1 week of their injury (median of 1 day), 5 of 7 athletes sustained recurrent subluxation events with a median (range) of four subluxation events per athlete (0 to 8) during the remainder of the season. Seven athletes were treated surgically after the completion of their season, four of whom returned to football. CONCLUSION: This study suggests that although collegiate football players are able to return to in-season sport after a posterior glenohumeral instability event, they will likely sustain multiple recurrent instability events and undergo surgery after the season is completed. The results of this study can help guide in-season management of posterior shoulder instability by allowing more appropriate postinjury counseling and decision making through the identification of those athletes who may require additional attention from medical staff during the season and possible modifications to training regimens to minimize long-term disability. Further prospective studies involving a larger cohort over several seasons should be performed through collaborative studies across the NCAA that better assess function and injury risk factors before beginning collegiate athletics. This would better characterize the natural history and associated functional limitations that athletes may encounter during their collegiate careers. LEVEL OF EVIDENCE: Level IV, prognostic study.

Generating the American Shoulder and Elbow Surgeons Score Using Multivariable Predictive Models and Computer Adaptive Testing to Reduce Survey Burden.

BACKGROUND: The preferred patient-reported outcome measure for the assessment of shoulder conditions continues to evolve. Previous studies correlating the Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive tests (CATs) to the American Shoulder and Elbow Surgeons (ASES) score have focused on a singular domain (pain or physical function) but have not evaluated the combined domains of pain and physical function that compose the ASES score. Additionally, previous studies have not provided a multivariable prediction tool to convert PROMIS scores to more familiar legacy scores. PURPOSE: To establish a valid predictive model of ASES scores using a nonlinear combination of PROMIS domains for physical function and pain. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: The Military Orthopaedics Tracking Injuries and Outcomes Network (MOTION) database is a prospectively collected repository of patient-reported outcomes and intraoperative variables. Patients in MOTION research who underwent shoulder surgery and completed the ASES, PROMIS Physical Function, and PROMIS Pain Interference at varying time points were included in the present analysis. Nonlinear multivariable predictive models were created to establish an ASES index score and then validated using "leave 1 out" techniques and minimal clinically important difference /substantial clinical benefit (MCID/SCB) analysis. RESULTS: A total of 909 patients completed the ASES, PROMIS Physical Function, and PROMIS Pain Interference at presurgery, 6 weeks, 6 months, and 1 year after surgery, providing 1502 complete observations. The PROMIS CAT predictive model was strongly validated to predict the ASES (Pearson coefficient = 0.76-0.78; R2 = 0.57-0.62; root mean square error = 13.3-14.1). The MCID/SCB for the ASES was 21.7, and the best ASES index MCID/SCB was 19.4, suggesting that the derived ASES index is effective and can reliably re-create ASES scores. CONCLUSION: The PROMIS CAT predictive models are able to approximate the ASES score within 13 to 14 points, which is 7 points more accurate than the ASES MCID/SCB derived from the sample. Our ASES index algorithm, which is freely available online (https://osf.io/ctmnd/), has a lower MCID/SCB than the ASES itself. This algorithm can be used to decrease patient survey burden by 11 questions and provide a reliable ASES analog to clinicians.

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort.

BACKGROUND: Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability. METHODS: Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images. RESULTS: Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm. CONCLUSIONS: This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to date and demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

The effectiveness of battlefield acupuncture in addition to standard physical therapy treatment after shoulder surgery: a protocol for a randomized clinical trial.

INTRODUCTION: There is a large incidence of shoulder instability among active young athletes and military personnel. Shoulder stabilization surgery is the commonly employed intervention for treating individuals with instability. Following surgery, a substantial proportion of individuals experience acute post-operative pain, which is usually managed with opioid pain medications. Unfortunately, the extended use of opioid medications can have adverse effects that impair function and reduce military operational readiness, but there are currently few alternatives. However, battlefield acupuncture (BFA) is a minimally invasive therapy demonstrating promise as a non-pharmaceutical intervention for managing acute post-operative pain. METHODS: This is a parallel, two-arm, single-blind randomized clinical trial. The two independent variables are intervention (2 levels, standard physical therapy and standard physical therapy plus battlefield acupuncture) and time (5 levels, 24 h, 48 h, 72 h, 1 week, and 4 weeks post shoulder stabilization surgery). The primary dependent variables are worst and average pain as measured on the visual analog scale. Secondary outcomes include medication usage, Profile of Mood States, and Global Rating of Change. DISCUSSION: The magnitude of the effect of BFA is uncertain; current studies report confidence intervals of between-group differences that include minimal clinically important differences between intervention and control groups. The results of this study may help determine if BFA is an effective adjunct to physical therapy in reducing pain and opioid usage in acute pain conditions. TRIAL REGISTRATION: ClinicalTrials.gov NCT04094246 . Registered on 16 September 2019.

Control-Normalized Fisher Ratio Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Data for Enhanced Biomarker Discovery in a Metabolomic Study of Orthopedic Knee-Ligament Injury.

An innovative form of Fisher ratio (F-ratio) analysis (FRA) is developed for use with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC-TOFMS) data and applied to the investigation of the changes in the metabolome in human plasma for patients with injury to their anterior cruciate ligament (ACL). Specifically, FRA provides a supervised discovery of metabolites that express a statistically significant variance in a two-sample class comparison: patients and healthy controls. The standard F-ratio utilizes the between-class variance relative to the pooled within-class variance. Because standard FRA is adversely impacted by metabolites expressed with a large within-class variance in the patient class, "control-normalized FRA" has been developed to provide complementary information, by normalizing the between-class variance to the variance of the control class only. Thirty plasma samples from patients who recently suffered from an ACL injury, along with matched controls, were subjected to GC × GC-TOFMS analysis. Following both standard and control-normalized FRA, the concentration ratio for the top 30 "hits" in each comparison was obtained and then t-tested for statistical significance. Twenty four out of 30 metabolites plus the therapeutic agent, naproxen (24/30), passed the t-test for the control-normalized FRA, which included 8/24 unique to control-normalized FRA and 16/24 in common with the standard FRA. Likewise, standard FRA provided 21/30 metabolites passing the t-test, with 5/21 undiscovered by control-normalized FRA. The complementary information obtained by both F-ratio analyses demonstrates the general utility of the new approach for a variety of applications.

Trunk and Lower Extremity Movement Patterns, Stress Fracture Risk Factors, and Biomarkers of Bone Turnover in Military Trainees.

CONTEXT: Military service members commonly sustain lower extremity stress fractures (SFx). How SFx risk factors influence bone metabolism is unknown. Understanding how SFx risk factors influence bone metabolism may help to optimize risk-mitigation strategies. OBJECTIVE: To determine how SFx risk factors influence bone metabolism. DESIGN: Cross-sectional study. SETTING: Military service academy. PATIENTS OR OTHER PARTICIPANTS: Forty-five men (agepre = 18.56 ± 1.39 years, heightpre = 176.95 ± 7.29 cm, masspre = 77.20 ± 9.40 kg; body mass indexpre = 24.68 ± 2.87) who completed Cadet Basic Training (CBT). Individuals with neurologic or metabolic disorders were excluded. INTERVENTION(S): We assessed SFx risk factors (independent variables) with (1) the Landing Error Scoring System (LESS), (2) self-reported injury and physical activity questionnaires, and (3) physical fitness tests. We assessed bone biomarkers (dependent variables; procollagen type I amino-terminal propeptide [PINP] and cross-linked collagen telopeptide [CTx-1]) via serum. MAIN OUTCOME MEASURE(S): A markerless motion-capture system was used to analyze trunk and lower extremity biomechanics via the LESS. Serum samples were collected post-CBT; enzyme-linked immunosorbent assays determined PINP and CTx-1 concentrations, and PINP : CTx-1 ratios were calculated. Linear regression models demonstrated associations between SFx risk factors and PINP and CTx-1 concentrations and PINP : CTx-1 ratio. Biomarker concentration mean differences with 95% confidence intervals were calculated. Significance was set a priori using α ≤ .10 for simple and α ≤ .05 for multiple regression analyses. RESULTS: The multiple regression models incorporating LESS and SFx risk factor data predicted the PINP concentration (R2 = 0.47, P = .02) and PINP : CTx-1 ratio (R2 = 0.66, P = .01). The PINP concentration was increased by foot internal rotation, trunk flexion, CBT injury, sit-up score, and pre- to post-CBT mass changes. The CTx-1 concentration was increased by heel-to-toe landing and post-CBT mass. The PINP : CTx-1 ratio was increased by foot internal rotation, lower extremity sagittal-plane displacement (inversely), CBT injury, sit-up score, and pre- to post-CBT mass changes. CONCLUSIONS: Stress fracture risk factors accounted for 66% of the PINP : CTx-1 ratio variability, a potential surrogate for bone health. Our findings provide insight into how SFx risk factors influence bone health. This information can help guide SFx risk-mitigation strategies.

Likelihood of Return to Duty Is Low After Meniscal Allograft Transplantation in an Active-duty Military Population.

BACKGROUND: Meniscal allograft transplantation (MAT) is considered a viable surgical treatment option in the symptomatic, postmeniscectomy knee and as a concomitant procedure with ACL revision and articular cartilage repair. Although promising outcomes have recently been reported in active and athletic populations, MAT has not been well-studied in the high-demand military population. QUESTIONS/PURPOSES: (1) What proportion of active-duty military patients who underwent MAT returned to full, unrestricted duty? (2) What demographic and surgical variables, if any, correlated with return to full, unrestricted duty? METHODS: Between 2005 and 2015, three fellowship-trained sports surgeons (TMD, SJS, BDO) performed 110 MAT procedures in active-duty military patients, of which 95% (104 patients) were available for follow-up at a minimum 2 years (mean 2.8 ± SD 1.1 year). During the study period, indications for MAT generally included unicompartmental pain and swelling in a postmeniscectomized knee and as a concomitant procedure when a meniscal-deficient compartment was associated with either an ACL revision reconstruction or cartilage repair. Demographic and surgical variables were collected and analyzed. The primary endpoints were the decision for permanent profile activity restrictions and military duty termination by a medical board. The term "medical board" implies termination of military service because of medical reasons. We elected to set statistical significance at p < 0.001 to reduce the potential for spurious statistical findings in the setting of a relatively small sample size. RESULTS: Forty-six percent (48 of 104) of eligible patients had permanent profile activity restrictions and 50% (52 of 104) eventually had their military duty terminated by a military board. Only 20% (21 of 104) had neither permanent profile activity restrictions nor medical-board termination and were subsequently able to return to full duty, and only 13% (13 of 104) continued unrestricted military service beyond 2 years after surgery. Age, gender, tobacco use, and BMI did not correlate with return to full duty. Combat arms soldiers were less likely to have permanent profile activity restrictions (odds ratio 4.76 [95% confidence interval 1.93 to 11.8]; p = 0.001) and were more likely to return to full duty than soldiers in support roles (OR 0.24 [95% CI 0.09 to 0.65]; p = 0.005), although these findings did not reach statistical significance. Officers were more likely to return to full duty than enlisted soldiers at more than 2 years after surgery (OR 17.44 [95% CI 4.56 to 66.65]; p < 0.001). No surgical variables correlated with return-to-duty endpoints. CONCLUSIONS: Surgeons should be aware of the low likelihood of return to military duty at more than 2 years after MAT and counsel patients accordingly. Based on this study, MAT does not appear to be compatible with continued unrestricted military duty for most patients. LEVEL OF EVIDENCE: IV, therapeutic study.

The Influence of Self-Reported Tobacco Use on Baseline Concussion Assessments.

INTRODUCTION: Baseline symptom, balance, and neurocognitive scores have become an integral piece of the concussion management process. Factors such as sleep, learning disorders, fitness level, and sex have been linked to differences in performance on baseline assessments; however, it is unclear how tobacco use may affect these scores. The objective of this study was to compare baseline concussion assessment scores between service academy cadets who use and do not use tobacco. METHODS: Cadets completed a standard battery of concussion baseline assessments per standard of care and were classified into two groups: tobacco users (n = 1,232) and nonusers (n = 5,922). Dependent variables included scores on the Balance Error Scoring System, Standardized Assessment of Concussion, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Brief Symptom Inventory-18, and Brief Sensation Seeking Scale (BSSS). Separate Mann-Whitney U-tests were used to compare all baseline assessment scores between groups with an adjusted P-value < 0.004. RESULTS: Cadets that used tobacco performed significantly worse on the impulse control (P < 0.001) section of the ImPACT, reported greater ImPACT symptom severity scores (P < 0.001), and were more likely to take risks as measured by the BSSS (P < 0.001). No differences were detected for Balance Error Scoring System, Standardized Assessment of Concussion, Brief Symptom Inventory-18, and Sport Concussion Assessment Tool-3 symptom scores, verbal memory, visual memory, visual-motor speed, or reaction time on the ImPACT (P > 0.004). CONCLUSIONS: Tobacco users performed significantly worse than tobacco nonusers on the impulse control section of the ImPACT, reported greater symptom severity scores on the ImPACT, and were more likely to take risks as measured by the BSSS. Despite statistical significance, these results should be interpreted with caution, as the overall effect sizes were very small. Future research should examine the influence of tobacco use on recovery post-concussion.

Functional Outcomes After Isolated and Combined Posterior Cruciate Ligament Reconstruction in a Military Population.

BACKGROUND: The rates of return to full activity, persistent disability, complications, and surgical revisions after operative management of posterior cruciate ligament (PCL) tears in a physically active population have not been reported. PURPOSE: To evaluate the clinical outcomes of active military patients with symptomatic PCL tears who underwent surgical reconstruction and compare outcomes between isolated PCL and multiligament injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Individuals undergoing surgical reconstruction of the PCL (Current Procedural Terminology code 29889) were isolated from the Military Health System Management Analysis and Reporting Tool between fiscal years 2005 and 2010. Demographic variables and rates of postoperative complications, activity limitations, rates of revision surgery, physical disability ratings, and ultimate medical discharge were recorded from the electronic medical record and US Army Physical Disability Agency database. RESULTS: A total of 182 patients underwent 193 surgeries, including 118 isolated PCL reconstructions and 75 multiligament knee reconstructions, with an average follow-up of 19.5 months. There were 174 primary procedures and 19 revision reconstructions. The mean ± SD patient age was 28.4 ± 7.2 years, with males comprising 96.2% of patients. The overall surgical complication rate was 12.4%, with a significantly higher rate in multiligament knee reconstructions compared with isolated PCL reconstructions (18.7% vs 8.5%; P = .045). Overall, 35.1% of patients were discharged from military service due to disability. Rates of discharge were significantly higher in those undergoing surgery at lower volume institutions (those that performed <2 PCL reconstructions per year during the study period) than those at higher volume institutions (41.1% vs 26%; P = .040). The overall revision rate was 10.9%, with no significant difference between the isolated PCL and multiligament knee reconstructions. Of the 103 patients with primary isolated PCL reconstructions, 35% underwent medical discharge for persistent knee complaints, and 12.6% required revision PCL reconstruction. The overall failure rate for primary isolated PCL reconstructions, which includes both revision surgery and knee-related medical discharge from military service, was 42.7%. CONCLUSION: In a physically active, military population, nearly one-third of patients were unable to return to previous level of military function, and 12.6% required revision at short-term follow-up due to persistent instability. Perioperative complication rates were significantly higher among patients with multiligament knee reconstructions.