Vertical Stenosis as a Morphological Risk Factor for Anterior Cruciate Ligament Ruptures in Children: A Magnetic Resonance Imaging-Based Comparison.

BACKGROUND: There are known anatomic variations that may lead to traumatic disruption of the anterior cruciate ligament (ACL) identified within adult and adolescent patients. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the parameters of pediatric knees diagnosed with and without an ACL injury by magnetic resonance imaging. The hypothesis was that children with ACL abnormalities would demonstrate an equivalent notch width index (NWI), but a larger notch height index (NHI), in comparison with age-matched patients without ACL abnormalities, suggesting an association with congenital morphology. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A retrospective comparison cohort study of pediatric knees was performed by evaluating those with a confirmed ACL rupture/deficiency and those with a benign diagnosis on magnetic resonance imaging. Overall, 6 osseous and cartilaginous measurements and 3 ratios (2 newly described) were determined. They were then grouped for statistical purposes by age: children aged 5 to 11 years and adolescents aged 12 to 19 years. RESULTS: A total of 119 (49 children) consecutive patients with an ACL injury and 139 (72 children) healthy patients met inclusion criteria. The interaction between ACL status and age was significant for condylar measurements (P≤ .001), tibial spine height (P = .003), vertical space above tibial spine (P≤ .001), and NWI (P≤ .001) by 2-way analysis of variance. Although the NHI (P < 0.001) and tibial spine prominence (P = 0.039) demonstrated stenosis in the adolescent group, they did not have significant interactions with age and ACL status (P > 0.05). Regarding the transcondylar width, only the children's group had a significant difference regarding ACL status (P < .001), and the mean values in the children's group with ACL tears were nearly identical to those in the adolescent group both with and without ACL tears. The children's group with ACL tears also had a significantly larger tibial spine height compared with healthy children (P < .001). CONCLUSION: Children, similar to adolescents, demonstrated the effect of the NWI on the risk of ACL tears, but only the adolescent group demonstrated stenosis with the NHI. The morphology of the knee in a child at risk for ACL rupture was not the same as that of an adolescent when considering all dimensions, but it did seem that it was more adolescent-like than child-like at the time of an ACL rupture, refuting the idea of congenital hypoplasia as a common cause.

Management of Pediatric and Adolescent Sublime Tubercle Injuries: Isolated and Complex Patterns Demonstrate Distinct Etiologies and Radiographic Outcomes.

BACKGROUND: The aim of this study was to assess the patient demographics, epidemiology, mechanism of injury, and natural history of sublime tubercle avulsion injuries. METHODS: A multicenter retrospective study was performed in which sublime tubercle avulsion injuries were identified by surgeon records and database query of radiology reports. Demographic data and imaging were reviewed for each case, and injuries were classified as type 1 (isolated injuries with a simple bony avulsion or periosteal stripping) or type 2 (complex injuries with an associated elbow fracture or dislocation). Treatment modality and evidence of radiographic healing at a minimum of 3 months were collected. RESULTS: Forty patients (78% male) with a median age of 15 years (range, 8 to 19 years) were identified with sublime tubercle avulsion injuries. Sixty-eight percent of cases (n=27) were determined to be type 1 injuries, and 32% (n=13) were classified as type 2 injuries. The majority of type 1 injuries (59%) occurred via a noncontact mechanism in overhead-throwing athletes, whereas 100% of the type 2 injuries were sustained via a contact mechanism. Type 1 injuries presented in a delayed manner in 19% of cases, whereas no type 2 injuries (0%) were delayed in presentation. Type 1 injuries infrequently underwent surgical intervention (19%), whereas 54% of type 2 injuries required surgery. Of those that did not undergo initial surgical management at a minimum of 3-month radiographic follow-up, 9/11 (82%) of type 1 injuries and 0/4 (0%) of type 2 injuries demonstrated evidence of healing. Only 1 case required reoperation (type 2 injury). CONCLUSIONS: This series of adolescents with sublime tubercle avulsion injuries expands our understanding of the epidemiology of this rare injury, which was previously only described as a noncontact injury in baseball players. Type 1 injuries are more likely to occur via a noncontact mechanism and generally demonstrate radiographic evidence of healing after a period of rigid immobilization. Conversely, type 2 injuries are more likely to undergo initial surgical intervention, and those managed nonoperatively are less likely to achieve radiographic healing. Further studies are needed to elucidate treatment protocols and long-term functional outcomes. LEVEL OF EVIDENCE: Level IV-case series.

Comparing outcomes in the treatment of pediatric and adolescent intraarticular radial head fractures.

Intraarticular radial head (IARH) fractures are uncommon pediatric injuries with unpredictable yet poor outcomes. The aim of this study was to evaluate clinical outcomes of IARH fractures in pediatric and adolescent patients, by testing our hypothesis that surgically managed fractures would have less risk for an unplanned second surgery and better elbow range of motion at the final follow-up. A retrospective review of 53 IARH fractures was performed. Demographic and clinical data were recorded. Concomitant and associated injuries were documented. Initial management and any attempted reduction in the emergency room were documented. The primary outcome was the need for an unplanned second procedure. Motion at final follow-up, presence of pain and need for physical therapy were reviewed. Radiographs were carefully reviewed and analyzed for physeal status, displacement, angulation and percent of radial head involved. We rejected our hypothesis, however, because it was displaced fractures that tended to require an unplanned change in treatment at a higher rate than nondisplaced fractures, regardless of index management with or without surgery. Fracture displacement on the lateral radiograph was a significant risk factor compared to the anterior-posterior images, and younger patients, particularly those with open physis, were at higher risk of an unplanned second procedure. Moreover, 80% of displaced fractures had asymmetric elbow motion after healing was achieved. It is important to counsel patients and families regarding the potential for suboptimal outcomes and elbow stiffness regardless of treatment choice, in the setting of an initially displaced IARH fracture. Level of evidence: Level III.

Sex Differences in the Incidence and Risk of Ankle-Foot Complex Stress Fractures Among U.S. Military Personnel.

Background: The objective of this study was to evaluate sex differences in the incidence and risk of ankle-foot complex (AFC) stress fractures among U.S. military personnel, which could assist in developing management strategies as females assume a greater role in U.S. military operations. Materials and Methods: The Defense Medical Epidemiology Database was used to identify all diagnosed AFC stress fractures in military personnel from 2006 to 2015. Cumulative incidence of AFC stress fractures was calculated and compared by year, service branch, and military rank. Sex differences in the risk of AFC stress fractures by occupation were examined, and integrated (i.e., male and female) occupations were compared with nonintegrated (i.e., male only) occupations. Results: A total of 43,990 AFC stress fractures were identified. The overall incidence rate was 2.76 per 1,000 person-years (p-y) for males and 5.78 per 1,000 p-y for females. Females consistently had higher incidence of AFC stress fractures across all subgroups, particularly among enlisted personnel. Female enlisted service members had the highest risk of AFC stress fractures in aviation (relative risk [RR] = 5.74; 95% confidence interval [CI]: 4.80-6.87) and artillery/gunnery (RR = 5.15; 95% CI: 4.62-5.75) occupations. Females in integrated occupations had significantly higher rates of AFC stress fractures than males in both integrated and nonintegrated occupations (i.e., special forces, infantry, and mechanized/armor). Conclusions: Females in the U.S. military have a higher risk of AFC stress fractures than males. As integration of females into previously sex-restricted occupations continues, focused prevention efforts may be needed to reduce injury burden and maximize medical readiness.

Vitamin D Deficiency in the Military: It's Time to Act!

Vitamin D is critically important to numerous physiologic functions, including bone health. Poor vitamin D status is a common but underrecognized problem that predisposes the military population to stress fracture and completed fracture. This has significant implications for force health protection, warfighter readiness, attrition, and cost. Despite this, vitamin D deficiency is still underdiagnosed and undertreated in the military. This is a major hindrance to military readiness and one that could easily be modified with awareness, prevention, and early treatment. In this commentary, we review the literature on vitamin D deficiency and critically examine the current status of policies and clinical practice related to vitamin D in the military health system. We offer several practical recommendations to increase awareness and readiness while decreasing musculoskeletal injury and the associated costs.