Ankle Arthroscopy Simulation Improves Basic Skills, Anatomic Recognition, and Proficiency During Diagnostic Examination of Residents in Training

BACKGROUND

The purpose of this study was to determine whether low-fidelity arthroscopic simulation training improves basic ankle arthroscopy performance and efficiency among orthopedic trainees.

METHODS

Twenty-nine orthopedic surgery trainees with varying levels of experience in ankle arthroscopy were randomized into either simulation or standard practice groups. At baseline testing, all participants performed simulator-based testing and a cadaveric diagnostic ankle arthroscopy with video recording. The simulation group subsequently received 4 one-on-one, 15-minute simulation training sessions over a 4-month period, while the standard practice group received no additional simulation training or exposure. After intervention, both groups were reevaluated with simulator testing and a second recorded cadaveric diagnostic ankle arthroscopy. Two blinded, independent experts evaluated each randomized arthroscopic performance using the 15-point checklist, Arthroscopic Surgery Skill Evaluation Tool (ASSET), and total elapsed time, and all outcome measures were compared within and between groups.

RESULTS

Baseline arthroscopic experience, simulator task performance measures, and ASSET scores were equivalent between the simulation and standard practice groups. After completion of training, the simulation group outscored the control group in total ASSET score (34.9 vs 19.6; P < .001) and checklist score (14.5 vs 8.4; P < .001) and achieved nearly expert ASSET Safety scores (4.7 vs 2.9; P < .001) on the simulator model. Cadaver testing also demonstrated significant improvements in total ASSET score (28.8 vs 16.8; P < .001), checklist score (12.6 vs 7.1; P < .001), and ASSET Safety score (3.9 vs 2.6; P < .001).

CONCLUSION

These results demonstrate that low-fidelity ankle arthroscopy simulation training can improve basic surgical skills, efficiency of movement, and anatomic recognition. The results suggest greater patient safety during ankle arthroscopy following simulation training.

LEVEL OF EVIDENCE

Level I, prospective comparative study.

Lower extremity stress fractures in the military

Stress fractures of the lower extremities are common among the military population and, more specifically, military recruits who partake in basic training. Both intrinsic and extrinsic factors play a role in the development of these injuries, and it is important to identify those individuals at risk early in their military careers. Some of these factors are modifiable, so they may become preventable injuries. It is important to reiterate that one stress fracture places the soldier at risk for future stress fractures; but the first injury should not be reason enough for separation from the military, as literature would support no long-term deficits from properly treated stress fractures. Early in the process, radiographic analysis is typically normal; continued pain may warrant advanced imaging, such as scintigraphy or MRI. Most stress fractures that are caught early are amendable to nonoperative management consisting of a period of immobilization and NWB followed by progressive rehabilitation to preinjury levels. Complete or displaced fractures may require operative intervention as do tension-sided FNSF. Improving dietary and preaccession physical fitness levels may play a role in reducing the incidence of stress fractures in the active-duty military population. It is important to keep in mind when evaluating soldiers and athletes who present with activity-related pain that stress fractures are not uncommon and should be given significant consideration.

The burden and management of sports-related musculoskeletal injuries and conditions within the US military

Military service members comprise a young and physically active population who are at increased risk for musculoskeletal injuries and conditions related to sports and physical training. Even during times of war, musculoskeletal injuries and conditions related to sports and physical training, not associated with combat, are the leading cause of medical evacuation from theater. As a result, these injuries significantly compromise military readiness, and they can lead to an increased risk for reinjury and long-term disability among military service members. Regardless of the mechanism of injury, the large volume and types of musculoskeletal injuries and conditions that affect soldiers are similar to those that are commonly seen and treated in sports medicine clinics and practices. Recently, the US Marine Corps, Navy, and Army have recognized the value of the sports medicine model of care to improve the access, efficiency, and effectiveness of care for solders who experience musculoskeletal injuries related to sports and training. A highly skilled sports medicine team of providers and allied health care professionals (eg, athletic trainers, physical therapists), with expertise in the prevention, assessment, diagnosis, and management of musculoskeletal injuries and conditions, will continue to be an integral cog in the effective management of these types of injuries into the future, as the sports medicine model continues to expand across the military health system.

Trends in the diagnosis of SLAP lesions in the US military

PURPOSE

Shoulder pathology, particularly SLAP (superior labrum anterior-posterior) lesions, is prevalent in overhead athletes and physically active individuals. The aim of this study is to quantify the burden of SLAP lesions in the military and establish risk factors for diagnosis.

METHODS

A retrospective analysis of all service members diagnosed with a SLAP lesion (International Classification of Disease, Ninth Revision code 840.70) in the Defense Medical Epidemiological Database between 2002 and 2009 was performed. Available epidemiological risk factors including age, sex, race, military rank, and branch of service were evaluated using multivariate Poisson regression analysis, and cumulative and subgroup incidence rates were calculated.

RESULTS

During the study period, approximately 23,632 SLAP lesions were diagnosed among a population at risk of 11,082,738, resulting in an adjusted incidence rate of 2.13 per 1,000 person-years. The adjusted annual incidence rate for SLAP lesions increased from 0.31 cases per 1,000 person-years in 2002 to 1.88 cases per 1,000 person-years in 2009, with an average annual increase of 21.2 % (95 % CI 20.7 %, 22.0 %, p < 0.0001) during the study period. Age, sex, race, branch of military service, and military rank were independent risk factors associated with the incidence rate of SLAP lesion (p < 0.01). Male service members were over twofold more likely (IRR, 2.12; 95 % CI 2.01, 2.23) to sustain a SLAP lesion when compared with females. Increasing age category was associated with a statistically significant increase in the incidence rate for SLAP lesions in the present study (p < 0.001). After controlling for the other variables, those individuals of white race, enlisted ranks, or Marine Corps service experienced the highest incidence rates for SLAP.

CONCLUSION

This is the first study to establish the epidemiology of SLAP lesions within an active military cohort in the American population. Sex, age, race, military rank, and branch of military service were all independently associated with the incidence rate of SLAP lesions in this physically active population at high risk for shoulder injury.

LEVEL OF EVIDENCE

II.

Management and prevention of acute and chronic lateral ankle instability in athletic patient populations

Acute and chronic lateral ankle instability are common in high-demand patient populations. If not managed appropriately, patients may experience recurrent instability, chronic pain, osteochondral lesions of the talus, premature osteoarthritis, and other significant long-term disability. Certain populations, including young athletes, military personnel and those involved in frequent running, jumping, and cutting motions, are at increased risk. Proposed risk factors include prior ankle sprain, elevated body weight or body mass index, female gender, neuromuscular deficits, postural imbalance, foot/ankle malalignment, and exposure to at-risk athletic activity. Prompt, accurate diagnosis is crucial, and evidence-based, functional rehabilitation regimens have a proven track record in returning active patients to work and sport. When patients fail to improve with physical therapy and external bracing, multiple surgical techniques have been described with reliable results, including both anatomic and non-anatomic reconstructive methods. Anatomic repair of the lateral ligamentous complex remains the gold standard for recurrent ankle instability, and it effectively restores native ankle anatomy and joint kinematics while preserving physiologic ankle and subtalar motion. Further preventative measures may minimize the risk of ankle instability in athletic cohorts, including prophylactic bracing and combined neuromuscular and proprioceptive training programs. These interventions have demonstrated benefit in patients at heightened risk for lateral ankle sprain and allow active cohorts to return to full activity without adversely affecting athletic performance.

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.

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.

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.

Risk factors for anterior glenohumeral instability

BACKGROUND

While anterior glenohumeral instability has been shown to be common in young athletes, the risk factors for injury are poorly understood.

PURPOSE/HYPOTHESIS

To determine the modifiable and nonmodifiable risk factors for anterior shoulder instability in a high-risk cohort. The hypothesis was that specific baseline factors would be associated with the subsequent risk of injury.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

We conducted a prospective cohort study in which 714 young athletes were followed from June 2006 through May 2010. Baseline assessments included a subjective history of instability, physical examination by a sports medicine fellowship-trained orthopaedic surgeon, range of motion, strength with a handheld dynamometer, and bilateral noncontrast shoulder magnetic resonance imaging (MRI). A musculoskeletal radiologist measured glenoid version, glenoid height, glenoid width, glenoid index (height-to-width ratio), glenoid depth, rotator interval (RI) height, RI width, RI area, RI index, and the coracohumeral interval. Subjects were followed to document all acute anterior shoulder instability events during the 4-year follow-up period. The time to anterior shoulder instability event during the follow-up period was the primary outcome of interest. Univariate and multivariable Cox proportional hazards regression models were used to analyze the data.

RESULTS

Complete data were available for 714 subjects. During the 4-year surveillance period, there were 39 anterior instability events documented at a mean of 285 days. While we controlled for covariates, significant risk factors of physical examination were as follows: apprehension sign (hazard ratio [HR], 2.96; 95% CI, 1.48-5.90; P = .002) and relocation sign (HR, 4.83; 95% CI, 1.75-13.33; P = .002). Baseline range of motion and strength measures were not associated with subsequent injury. Significant anatomic risk factors on MRI measurement were glenoid index (HR, 8.12; 95% CI, 1.07-61.72; P = .043) and the coracohumeral interval (HR, 1.20; 95% CI, 1.08-1.34; P = .001).

CONCLUSION

This prospective cohort study revealed significant risk factors for shoulder instability in this high-risk population. Physical examination findings of apprehension and relocation were significant while controlling for history of injury. The anatomic variables of significance were not surprising-tall and thin glenoids were at higher risk compared with short and wide glenoids, and the risk of instability increased by 20% for every 1-mm increase in coracohumeral distance.

Seven steps for developing and implementing a preventive training program: lessons learned from JUMP-ACL and beyond

Musculoskeletal injuries during military and sport-related training are common, costly and potentially debilitating. Thus, there is a great need to develop and implement evidence-based injury prevention strategies to reduce the burden of musculoskeletal injury. The lack of attention to implementation issues is a major factor limiting the ability to successfully reduce musculoskeletal injury rates using evidence-based injury prevention programs. We propose 7 steps that can be used to facilitate successful design and implementation of evidence-based injury prevention programs within the logical constraints of a real-world setting by identifying implementation barriers and associated solutions. Incorporating these 7 steps along with other models for behavioral health interventions may improve the overall efficacy of military and sport-related injury prevention programs.

Reported Concussion Rates for Three Division I Football Programs: An Evaluation of the New NCAA Concussion Policy

Background:

There has been increased interest in the number of concussions occurring in college football over the past year. In April 2010, the National Collegiate Athletic Association (NCAA) published new guidelines for the diagnosis and treatment of concussions in student athletes.

Purpose:

To determine the number of concussions that occurred on 3 collegiate Division I military academy football teams prior to and following recent changes in the NCAA concussion management policy.

Study Design:

Descriptive epidemiology study.

Methods:

Injury reports were reviewed from 3 Division I military academy football teams. The number of concussions that occurred over the 2009-2010 and 2010-2011 seasons, including those sustained in practice and game situations, was determined for each team. Incidence rates were compared using the exact binomial method.

Results:

The combined concussion incidence rate doubled from 0.57 per 1000 athlete exposures in the 2009-2010 season to 1.16 per 1000 athlete exposures in the 2010-2011 season (incidence rate ratio, 2.04; 95% CI, 1.2-3.55; P = 0.01). The combined numbers of concussions for the 2009-2010 and 2010-2011 seasons were 23 (40,481 exposures) and 42 (36,228), respectively.

Conclusion:

The combined incidence rate of concussions for the 2010-2011 season doubled from the previous season after the implementation of new NCAA policies on concussion management. While the institution of a more formalized concussion plan on the part of medical staff is one possible factor, another may have been the increased recognition and reporting on the part of players and coaches after the rule change.

Risk of Lower Extremity Injury in a Military Cadet Population After a Supervised Injury-Prevention Program

CONTEXT

 Specific movement patterns have been identified as possible risk factors for noncontact lower extremity injuries. The Dynamic Integrated Movement Enhancement (DIME) was developed to modify these movement patterns to decrease injury risk.

OBJECTIVE

 To determine if the DIME is effective for preventing lower extremity injuries in US Military Academy (USMA) cadets.

DESIGN

 Cluster-randomized controlled trial.

SETTING

 Cadet Basic Training at USMA.

PATIENTS OR OTHER PARTICIPANTS

 Participants were 1313 cadets (1070 men, 243 women).

INTERVENTION(S)

 Participants were cluster randomized to 3 groups. The active warm-up (AWU) group performed standard Army warm-up exercises. The DIME groups were assigned to a DIME cadre-supervised (DCS) group or a DIME expert-supervised (DES) group; the former consisted of cadet supervision and the latter combined cadet and health professional supervision. Groups performed exercises 3 times weekly for 6 weeks.

MAIN OUTCOME MEASURE(S)

 Cumulative risk of lower extremity injury was the primary outcome. We gathered data during Cadet Basic Training and for 9 months during the subsequent academic year. Risk ratios and 95% confidence intervals (CIs) were calculated to compare groups.

RESULTS

 No differences were seen between the AWU and the combined DIME (DCS and DES) groups during Cadet Basic Training or the academic year. During the academic year, lower extremity injury risk in the DES group decreased 41% (relative risk [RR] = 0.59; 95% CI = 0.38, 0.93; P = .02) compared with the DCS group; a nonsignificant 25% (RR = 0.75; 95% CI = 0.49, 1.14; P = .18) decrease occurred in the DES group compared with the AWU group. Finally, there was a nonsignificant 27% (RR = 1.27; 95% CI = 0.90, 1.78; P = .17) increase in injury risk during the academic year in the DCS group compared with the AWU group.

CONCLUSIONS

 We observed no differences in lower extremity injury risk between the AWU and combined DIME groups. However, the magnitude and direction of the risk ratios in the DES group compared with the AWU group, although not statistically significant, indicate that professional supervision may be a factor in the success of injury-prevention programs.

The epidemiology of medial collateral ligament sprains in young athletes

BACKGROUND

A medial collateral ligament (MCL) knee sprain is a prevalent injury in athletic populations that may result in significant time lost to injury. Remarkably little is known of the epidemiology of this injury.

PURPOSE

To define the incidence of MCL tears and to determine the demographic and athletic risk factors.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

A longitudinal cohort study was performed to examine the epidemiology of isolated MCL sprains at the United States Military Academy (USMA) between 2005 and 2009. Charts and radiographic studies were reviewed by an independent orthopaedic surgeon to identify all new isolated MCL sprains resulting in time lost to sport and activity that occurred within the study period. Incidence rates (IRs) with 95% confidence intervals (CIs) were calculated per 1000 person-years at risk and by sex, sport, and level of competition. The IR per 1000 athlete-exposures (AEs) was also determined. Incidence rate ratios (IRRs) and respective 95% CIs were calculated between male and female students, intercollegiate and intramural athletes, and male and female intercollegiate athletes involved in selected sports. Chi-square and Poisson regression analyses were used to examine the relationship between the variables of interest and the incidence of MCL sprains, with statistical significance set at P < .05.

RESULTS

A total of 128 cadets sustained isolated MCL injuries during 17,606 student person-years from 2005 to 2009. This resulted in an IR of approximately 7.3 per 1000 person-years. Of the 128 injuries, 114 were in male athletes (89%) and 14 were in female athletes (11%). Male cadets had a 44% higher IR than did female cadets (7.60 vs 5.36, respectively), although this was not significant (P = .212). Of 5820 at-risk intercollegiate athletes, 59 (53 male, 6 female) sustained an isolated MCL sprain during 528,523 (407,475 male, 121,048 female) AEs for an overall IR of 10.14 per 1000 person-years and 0.11 per 1000 AEs. The IRR of MCL sprains of men compared with women involved in intercollegiate athletics was 2.87 (95% CI, 1.24-8.18) per 1000 person-years and 2.62 (95% CI, 1.13-7.47) per 1000 AEs. Of 21,805 at-risk intramural athletes, with quarterly participation, 16 (all male) sustained isolated MCL injuries during 225,683 AEs for an overall IR of 0.07 per 1000 AEs. The IRs of MCL injuries of intercollegiate and intramural athletes did not differ significantly. In intercollegiate sports, wrestling (0.57), judo (0.36), hockey (0.34), and rugby (men's, 0.22; women's, 0.23) had the highest IRs per 1000 AEs. When examining men's intercollegiate athletics, the IRRs of wrestling (13.41; 95% CI, 1.80-595.27) and hockey (8.12; 95% CI, 0.91-384.16) were significantly higher compared with that of lacrosse. Among women's intercollegiate sports as well as intramural sports, there were no significant differences in IRs. A median of 16 days was lost to injury, with 2407 total days lost for all injuries. Grade 1 MCL injuries lost a median of 13.5 days, while higher grade injuries lost a median of 29 days.

CONCLUSION

Medial collateral ligament injuries are relatively common in athletic cohorts. The most injurious sports are contact sports such as wrestling, hockey, judo, and rugby. Male athletes are at a greater risk than female athletes. Intercollegiate athletes are at a greater risk than intramural athletes. The average amount of time lost per injury was 23.2 days, with greater time lost with higher grade sprains than grade 1 sprains.

Outcomes after bankart repair in a military population: predictors for surgical revision and long-term disability

PURPOSE

To quantify the rate of surgical failure after anterior shoulder stabilization procedures, as well as to identify demographic and surgical risk factors associated with poor outcomes.

METHODS

All Army patients undergoing arthroscopic or open Bankart repair for shoulder instability were isolated from the Military Health System Management Analysis and Reporting Tool between 2003 and 2010. Demographic variables (age, gender) and surgical variables (treatment facility volume, admission status, surgical technique) were extracted. Rates of surgical failure, defined as subsequent revision surgery or medical discharge with persistent shoulder complaints, were recorded from the electronic medical record and US Army Physical Disability Agency database. Risk factor analysis was performed with univariate t tests, χ(2) tests, and a multivariable logistic regression model with failure as the outcome.

RESULTS

A total of 3,854 patients underwent Bankart repair during the study period, with most procedures having been performed arthroscopically (n = 3,230, 84%) and on an outpatient basis (n = 3,255, 84%). Patients were predominately men (n = 3,531, 92%), and the mean age was 28.0 years (SD, 7.5 years). A total of 193 patients (5.0%) underwent revision stabilization whereas 339 patients (8.8%) were medically discharged with complaints of shoulder instability, for a total combined failure rate of 13.8% (n = 532). Univariate analyses showed no significant effect for gender; however, younger age, higher facility volume, open repair, and inpatient status were significant factors associated with subsequent surgical failure. Multivariable analyses confirmed that young age (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.91 to 0.96; P < .001), open repair (OR, 0.52; 95% CI, 0.36 to 0.75; P = .001), and inpatient status (OR, 0.58; 95% CI, 0.40 to 0.84; P = .004) were independently associated with failure by revision surgery.

CONCLUSIONS

Young age remains a significant risk factor for surgical failure after Bankart repair. Patients who underwent arthroscopic Bankart repair had a significantly lower surgical failure rate (4.5%) than patients who underwent open anterior stabilization (7.7%). Despite advances in surgical technique, 1 in 20 military service members required revision surgery after failed primary stabilization in this study.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

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.

Isometric shoulder strength reference values for physically active collegiate males and females

Background:

It is common clinical practice to assess muscle strength during examination of patients following shoulder injury or surgery. Strength comparisons are often made between the patient’s injured and uninjured shoulders, with the uninjured side used as a reference without regard to upper extremity dominance. Despite the importance of strength measurements, little is known about expected normal baselines of the uninjured shoulder. The purpose of this study was to report normative values for isometric shoulder strength for physically active college-age men and women without history of shoulder injury.

Methods:

University students—546 males (18.8 ± 1.0 years, 75.3 ± 12.2 kg) and 73 females (18.7 ± 0.9 years, 62.6 ± 7.0 kg)—underwent thorough shoulder evaluations by an orthopaedic surgeon and completed bilateral isometric strength measurements with a handheld dynamometer. Variables measured included internal rotation, external rotation, abduction, supine internal rotation and external rotation at 45°, and lower trapezius in prone flexion.

Results:

Significant differences were found between the dominant and nondominant shoulder for internal rotation, internal rotation at 45°, abduction, and prone flexion in males and in internal rotation at 45° and prone flexion for females (P ≤ 0.01).

Risk factors for posterior shoulder instability in young athletes

BACKGROUND

While posterior glenohumeral instability is becoming increasingly common among young athletes, little is known of the risk factors for injury.

PURPOSE

To determine the modifiable and nonmodifiable risk factors for posterior shoulder instability in a high-risk cohort.

STUDY DESIGN

Case-control study (prognosis); Level of evidence, 2.

METHODS

A prospective cohort study in which 714 young athletes were followed from June 2006 through May 2010 was conducted. Baseline testing included a subjective history of instability, instability testing by a sports medicine fellowship-trained orthopaedic surgeon, range of motion, strength measurement with a handheld dynamometer, and bilateral noncontrast magnetic resonance imaging of the shoulder. A musculoskeletal radiologist measured glenoid version, height, depth, rotator interval (RI) height, RI width, RI area, and RI index. Participants were followed to document all acute posterior shoulder instability events during the 4-year follow-up period. The time to the posterior shoulder instability event during the follow-up period was the primary outcome of interest. Univariate and multivariable Cox proportional hazards regression models were used to analyze the data.

RESULTS

Complete data on 714 participants were obtained. During the 4-year surveillance period, 46 shoulders sustained documented glenohumeral instability events, of which only 7 were posterior in direction. The baseline factors that were associated with subsequent posterior instability during follow-up were increased glenoid retroversion (P < .0001), increased external rotation strength in adduction (P = .029) and at 45° of abduction (P = .015), and increased internal rotation strength in adduction (P = .038).

CONCLUSION

This is the largest known prospective study to follow healthy participants in the development of posterior shoulder instability. Posterior instability represents 10% of all instability events. The most significant risk factor was increased glenoid retroversion. While increased internal/external strength was also associated with subsequent instability, it is unclear whether these strength differences are causative or reactive to the difference in glenoid anatomy. This work confirms that increased glenoid retroversion is a significant prospective risk factor for posterior instability.

Changes in serum biomarkers of cartilage turnover after anterior cruciate ligament injury

BACKGROUND

Biomarkers of cartilage turnover and joint metabolism have a potential use in detecting early degenerative changes after a traumatic knee joint injury; however, no study has analyzed biomarkers before an anterior cruciate ligament (ACL) injury and again after injury or in comparison with a similar group of uninjured controls.

HYPOTHESIS

Changes in serum biomarker levels and the ratio of cartilage degradation to synthesis, from baseline to follow-up, would be significantly different between ACL-injured patients and uninjured controls.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This case-control study was conducted to examine changes in serum biomarkers of cartilage turnover following ACL injury in a young athletic population. Specifically, 2 markers for type II collagen and aggrecan synthesis (CPII and CS846, respectively) and 2 markers of types I and II degradation and type II degradation only (C1,2C and C2C, respectively) were studied. Preinjury baseline serum samples and postinjury follow-up samples were obtained for 45 ACL-injured cases and 45 uninjured controls matched for sex, age, height, and weight.

RESULTS

Results revealed significant decreases in C1,2C (P = .042) and C2C (P = .006) over time in the ACL-injured group when compared with the controls. The change in serum concentrations of CS846 from baseline to follow-up was also significantly different between the ACL-injured patients and uninjured controls (P = .002), as was the change between groups in the ratio of C2C:CPII over time (P = .013). No preinjury differences in the ratio of C1,2C:CPII or C2C:CPII were observed between groups; however, postinjury differences were observed for both ratios.

CONCLUSION

Changes in biomarker concentrations after an ACL injury suggest an alteration in cartilage turnover and joint metabolism in those sustaining ACL injuries compared with uninjured matched controls.

Rotator Cuff Weakness Is Not a Risk Factor for First-Time Anterior Glenohumeral Instability

Background:

Shoulder instability is a common problem in young athletes and can lead to pain and decreased ability to participate in high-level activities. Little is known about the modifiable risk factors for glenohumeral joint instability.

Hypothesis:

Isometric shoulder strength at baseline would be a modifiable risk factor associated with subsequent first-time anterior instability events.

Study Design:

Cohort study.

Methods:

Study participants were freshmen entering the United States Military Academy in June 2006. All participants completed bilateral isometric strength evaluations with a hand-held dynamometer at baseline upon entry into the study. Variables measured included internal and external rotation at 0° (IR0, ER0) and internal and external rotation at 45° of abduction (IR45, ER45). All subjects were followed for subsequent glenohumeral joint instability events until graduation in May 2010. Independent t tests were used to analyze the data.

Results:

Baseline strength data were available for 1316 shoulders with no prior history of instability, of which 26 went on to have an acute first-time anterior shoulder instability event while the individuals were at the academy. There were no significant differences in mean strength between shoulders that did not go on to develop instability (uninjured; n = 1290) and those that did develop anterior instability (injured; n = 26). The mean strength values in pounds of force for uninjured and injured shoulders, respectively, were as follows: IR0 (49.80 vs 49.29; P = .88), ER0 (35.58 vs 33.66; P = .27), IR45 (47.38 vs 46.93; P = .88), and ER45 (40.08 vs 38.98; P = .59).

Conclusion:

No association was found between isometric shoulder strength measures at baseline and subsequent first-time anterior glenohumeral joint instability within the high-risk athletic population studied in this prospective cohort.

Military movement training program improves jump-landing mechanics associated with anterior cruciate ligament injury risk

As part of the physical education program at the United States Military Academy, all cadets complete a movement training course designed to develop skills and improve performance in military-related physical tasks as well as obstacle navigation. The purpose of this study was to determine if completion of this course would also result in changes in jump-landing technique that reduce the risk of anterior cruciate ligament (ACL) injury. Analysis of landing mechanics on a two-footed jump landing from a height of 30 cm with a three-dimensional motion capture system synchronized with two force plates revealed both positive and negative changes. Video assessment using the Landing Error Scoring System (LESS) revealed an overall improved landing technique (p=.001) when compared to baseline assessments. The studied military movement course appears to elicit mixed but overall improved lower extremity jump-landing mechanics associated with risk for ACL injury.

Surgical treatment of chronic exertional compartment syndrome of the leg: failure rates and postoperative disability in an active patient population

BACKGROUND

Chronic exertional compartment syndrome of the leg is a frequent source of lower-extremity pain in military personnel, competitive athletes, and runners. We are not aware of any previous study in which the authors rigorously evaluated the rates of return to full activity, persistent disability, and surgical revision after operative management of chronic exertional compartment syndrome of the leg in a large, physically active population.

METHODS

Individuals who had undergone surgical fasciotomy of the anterior, lateral, and/or posterior compartments (current procedural terminology [CPT] codes 27600, 27601, and 27602) for nontraumatic compartment syndrome of the lower extremity (International Classification of Diseases, Ninth Revision [ICD-9] code 729.72) between 2003 and 2010 were identified from the Military Health System Management Analysis and Reporting Tool (M2). Demographic variables including age, sex, and rank were extracted, and rates of postoperative complications, activity limitations, and revision surgery or medical discharge were obtained from the electronic medical record and U.S. Army Physical Disability Agency database.

RESULTS

A total of 611 patients underwent 754 surgical procedures. The average patient age was 28.0 years, and 91.8% of the patients were male. Of the surgical procedures, 77.4% involved only anterior and lateral compartment releases; 19.4% addressed the anterior, lateral, and posterior compartments; and 2.2% addressed the posterior compartments alone. Symptom recurrence was reported by 44.7% of the patients, and 27.7% were unable to return to full activity. Surgical complications were documented for 15.7% of the patients, 5.9% underwent surgical revision, and 17.3% were referred for medical discharge because of chronic exertional compartment syndrome. Univariate analysis of prognostic factors revealed that surgical failure was associated with bilateral involvement (odds ratio [OR], 1.64), perioperative complications (OR, 2.12), activity limitations (OR, 4.41), and persistence of preoperative symptoms (OR, 8.46). Multivariable analysis confirmed significant associations between surgical failure and perioperative complications (OR, 1.72), activity limitations (OR, 2.23), and persistence of preoperative symptoms (OR, 5.47), whereas other factors were not significantly associated with surgical failure.

CONCLUSIONS

Chronic exertional compartment syndrome is a substantial contributor to lower-extremity disability in the military population. Nearly half of all service members undergoing fasciotomy reported persistent symptoms, and one in five individuals had unsuccessful surgical treatment.

History of shoulder instability and subsequent injury during four years of follow-up: a survival analysis

BACKGROUND

Little is known about the risk factors for glenohumeral joint instability. We hypothesized that a prior history of instability would be a significant risk factor for subsequent injury.

METHODS

We conducted a prospective cohort study over a four-year period within a high-risk group of young athletes to address the research hypothesis. Subjects were freshmen entering the U.S. Military Academy in June of 2006. Part of the baseline assessment included documenting a prior history of glenohumeral instability on entry into the study. All subjects were followed for subsequent glenohumeral joint instability events until graduation in May of 2010. The primary outcome of interest in this study was time to glenohumeral instability event during the follow-up period. We examined injury outcomes, looking for any instability, anterior instability, and posterior instability events. Cox proportional-hazards regression models were used to analyze the data.

RESULTS

Among the 714 subjects, eight shoulders were excluded from the analyses due to prior surgical stabilization, leaving 1420 shoulders, of which 126 had a self-reported prior history of instability. There were forty-six (thirty-nine anterior and seven posterior) acute instability events documented in the cohort during the follow-up period. Subjects with a prior history of instability were over five times (p < 0.001) more likely to sustain an acute (anterior or posterior) instability event during the follow-up period. Subjects with a history of instability were also 5.6 times (p < 0.001) more likely to experience a subsequent anterior instability event and 4.6 times (p = 0.068) more likely to experience a posterior instability event during follow-up. Similar results were observed in multivariable models after controlling for the influence of demographic and baseline physical examination findings.

CONCLUSIONS

Despite meeting the rigorous physical induction standards for military service, subjects with a prior history of glenohumeral joint instability were approximately five times more likely to experience a subsequent instability event, regardless of direction, within this high-risk athletic population.

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.