A Narrative Review of Metatarsal Bone Stress Injury in Athletic Populations: Etiology, Biomechanics, and Management

Return to sport following low-risk and high-risk bone stress injuries: a systematic review and meta-analysis

OBJECTIVE

Bone stress injuries (BSIs) are classified in clinical practice as being at low- or high-risk for complication based on the injury location. However, this dichotomous approach has not been sufficiently validated. The purpose of this systematic review was to examine the prognostic role of injury location on return-to-sport (RTS) and treatment complications after BSI of the lower extremity and pelvis.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Web of Science, Cochrane CENTRAL and Google Scholar databases were searched from database inception to December 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Peer-reviewed studies that reported site-specific RTS of BSIs in athletes.

RESULTS

Seventy-six studies reporting on 2974 BSIs were included. Sixteen studies compared multiple injury sites, and most of these studies (n=11) described the anatomical site of injury as being prognostic for RTS or the rate of treatment complication. Pooled data revealed the longest time to RTS for BSIs of the tarsal navicular (127 days; 95% CI 102 to 151 days) and femoral neck (107 days; 95% CI 79 to 135 days) and shortest duration of time for BSIs of the posteromedial tibial shaft (44 days, 95% CI 27 to 61 days) and fibula (56 days; 95% CI 13 to 100 days). Overall, more than 90% of athletes successfully returned to sport. Treatment complication rate was highest in BSIs of the femoral neck, tarsal navicular, anterior tibial shaft and fifth metatarsal; and lowest in the fibula, pubic bone and posteromedial tibial shaft.

CONCLUSION

This systematic review supports that the anatomical site of BSIs influences RTS timelines and the risk of complication. BSIs of the femoral neck, anterior tibial shaft and tarsal navicular are associated with increased rates of complications and more challenging RTS.

PROSPERO REGISTRATION NUMBER

CRD42021232351.

Stress fractures

Stress fractures (SF) represent 10%-20% of all injuries in sport medicine. An SF occurs when abnormal and repetitive loading is applied on normal bone: The body cannot adapt quickly enough, leading to microdamage and fracture. The etiology is multifactorial with numerous risk factors involved. Diagnosis of SF can be achieved by identifying intrinsic and extrinsic factors, obtaining a good history, performing a physical exam, and ordering laboratory and imaging studies (magnetic resonance imaging is the current gold standard). Relative energy deficiency in sport (RED-S) is a known risk factor. In addition, for women, it is very important know the menstrual status to identify long periods of amenorrhea in the past and the present. Early detection is important to improve the chance of symptom resolution with conservative treatment. Common presentation involves complaints of localized pain, with or without swelling, and tenderness on palpation of bony structures that begins earlier in training and progressively worsens with activity over a 2- to 3-week period. Appropriate classification of SF based on type, location, grading, and low or high risk is critical in guiding treatment strategies and influencing the time to return to sport. Stress injuries at low-risk sites are typically managed conservatively. Studies have suggested that calcium and vitamin D supplementation might be helpful. Moreover, other treatment regimens are not well established. Understanding better the pathophysiology of SFs and the potential utility of current and future bone-active therapeutics may well yield approaches that could treat SFs more effectively.

Resistance Exercise for Improving Running Economy and Running Biomechanics and Decreasing Running-Related Injury Risk: A Narrative Review

It is well-accepted that at least a certain amount of resistance exercise (RE) is recommended for most endurance athletes. In this review, we aim to summarize the evidence regarding the effects of RE on running economy, running biomechanics, and running-related injury risk in endurance runners. The evidence robustly shows that lower limb RE is effective for improving running economy and performance, with a combination of strength and plyometric training being recommended to improve RE. Isometric training is also emerging as a possible alternative to implement during periods of high overall training load. Lower limb RE may change some aspects of joint kinematics during running; however, the evidence regarding the effects on kinetics is limited. Lower limb RE may help reduce running-related injury risk, but further evidence is needed.

Medical and Biomechanical Risk Factors for Incident Bone Stress Injury in Collegiate Runners: Can Plantar Pressure Predict Injury?

Background:

Bone stress injury (BSI) is a common reason for missed practices and competitions in elite track and field runners.

Hypothesis:

It was hypothesized that, after accounting for medical risk factors, higher plantar loading during running, walking, and athletic movements would predict the risk of future BSI in elite collegiate runners.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 39 elite collegiate runners (24 male, 15 female) were evaluated during the 2014-2015 academic year to determine the degree to which plantar pressure data and medical history (including Female and Male Athlete Triad risk factors) could predict subsequent BSI. Runners completed athletic movements while plantar pressures and contact areas in 7 key areas of the foot were recorded, and the measurements were reported overall and by specific foot area. Regression models were constructed to determine factors related to incident BSI.

Results:

Twenty-one runners (12 male, 9 female) sustained ≥1 incident BSI during the study period. Four regression models incorporating both plantar pressure measurements and medical risk factors were able to predict the subsequent occurrence of (A) BSIs in female runners, (B) BSIs in male runners, (C) multiple BSIs in either male or female runners, and (D) foot BSIs in female runners. Model A used maximum mean pressure (MMP) under the first metatarsal during a jump takeoff and only misclassified 1 female with no BSI. Model B used increased impulses under the hindfoot and second through fifth distal metatarsals while walking, and under the lesser toes during a cutting task, correctly categorizing 83.3% of male runners. Model C used higher medial midfoot peak pressure during a shuttle run and triad cumulative risk scores and correctly categorized 93.3% of runners who did not incur multiple BSIs and 66.7% of those who did. Model D included lower hindfoot impulses in the shuttle run and higher first metatarsal MMP during treadmill walking to correctly predict the subsequent occurrence of a foot BSI for 75% of women and 100% without.

Conclusion:

The models collectively suggested that higher plantar pressure may contribute to risk for BSI.

Bone stress injuries

Bone stress injuries, including stress fractures, are overuse injuries that lead to substantial morbidity in active individuals. These injuries occur when excessive repetitive loads are introduced to a generally normal skeleton. Although the precise mechanisms for bone stress injuries are not completely understood, the prevailing theory is that an imbalance in bone metabolism favours microdamage accumulation over its removal and replacement with new bone via targeted remodelling. Diagnosis is achieved by a combination of patient history and physical examination, with imaging used for confirmation. Management of bone stress injuries is guided by their location and consequent risk of healing complications. Bone stress injuries at low-risk sites typically heal with activity modification followed by progressive loading and return to activity. Additional treatment approaches include non-weight-bearing immobilization, medications or surgery, but these approaches are usually limited to managing bone stress injuries that occur at high-risk sites. A comprehensive strategy that integrates anatomical, biomechanical and biological risk factors has the potential to improve the understanding of these injuries and aid in their prevention and management.

Survey on Video-Based Biomechanics and Biometry Tools for Fracture and Injury Assessment in Sports

This work presents a survey literature review on biomechanics, specifically aimed at the study of existent biomechanical tools through video analysis, in order to identify opportunities for researchers in the field, and discuss future proposals and perspectives. Scientific literature (journal papers and conference proceedings) in the field of video-based biomechanics published after 2010 were selected and discussed. The most common application of the study of biomechanics using this technique is sports, where the most reported applications are american football, soccer, basketball, baseball, jumping, among others. These techniques have also been studied in a less proportion, in ergonomy, and injury prevention. From the revised literature, it is clear that biomechanics studies mainly focus on the analysis of angles, speed or acceleration, however, not many studies explore the dynamical forces in the joints. The development of video-based biomechanic tools for force analysis could provide methods for assessment and prediction of biomechanical force associated risks such as injuries and fractures. Therefore, it is convenient to start exploring this field. A few case studies are reported, where force estimation is performed via manual tracking in different scenarios. This demonstration is carried out using conventional manual tracking, however, the inclusion of similar methods in an automated manner could help in the development of intelligent healthcare, force prediction tools for athletes and/or elderly population. Future trends and challenges in this field are also discussed, where data availability and artificial intelligence models will be key to proposing new and more reliable methods for biomechanical analysis.