Stress fractures in female athletes. Diagnosis, management and rehabilitation

Criteria and Guidelines for Returning to Running Following a Tibial Bone Stress Injury: A Scoping Review

Tibial bone stress injuries (BSIs) are common among long-distance runners. They have a high recurrence rate, and complexity emerges in the wider management and successful return to running. Following a tibial BSI, a critical component of complete rehabilitation is the successful return to running, and there is a lack of consistency or strong evidence to guide this process. The objectives of this review were to outline the criteria used in clinical decision-making prior to resuming running, and to establish evidence-based guidelines for the return to running process following a tibial BSI. Electronic databases including MEDLINE, CINAHL, Scopus, SPORTDiscus and AMED were searched for studies that stated criteria or provided guidelines on the objectives above. Fifty studies met the inclusion criteria and were included. Thirty-nine were reviews or clinical commentaries, three were retrospective cohort studies, two were randomised controlled trials, two were pilot studies, one was a prospective observational study, and three were case studies. Therefore, the recommendations that have been surmised are based on level IV evidence. Decisions on when an athlete should return to running should be shared between clinicians, coaches and the athlete. There are five important components to address prior to introducing running, which are: the resolution of bony tenderness, pain-free walking, evidence of radiological healing in high-risk BSIs, strength, functional and loading tests, and the identification of contributing factors. Effective return to running planning should address the athlete's risk profile and manage the risk by balancing the athlete's interests and reinjury prevention. An individualised graduated return to running programme should be initiated, often starting with walk-run intervals, progressing running distance ahead of speed and intensity, with symptom provocation a key consideration. Contributing factors to the initial injury should be addressed throughout the return to run process.

Developing a diagnostic framework for patients presenting with Exercise Induced Leg Pain (EILP): a scoping review

BACKGROUND

Numerous conditions are grouped under the generic term exercise-induced leg pain (EILP), yet clear diagnostic guidelines are lacking. This scoping review was conducted to clarify the definition and diagnostic criteria of nine commonly occurring EILP conditions.

METHODS

Three online databases were searched from inception to April 2022 for any English language original manuscripts identifying, describing, or assessing the clinical presentation and diagnostic criteria of the nine most common conditions that cause EILP. We included manuscripts considering all adults with any reported diagnostic criteria for EILP in any setting. Methodological quality was assessed using the Mixed Method Appraisal tool. Condition definitions were identified and categorised during data charting. Twenty-five potential elements of the history, 24 symptoms, 41 physical signs, 21 investigative tools, and 26 overarching diagnostic criteria, were identified and coded as counts of recommendation per condition, alongside qualitative analysis of the clinical reasoning. Condition definitions were constructed with 11 standardised elements based on recent consensus exercises for other conditions.

RESULTS

One hundred nineteen retained manuscripts, of which 18 studied multiple conditions, had a median quality of 2/5. A combination of the history, pain location, symptoms, physical findings, and investigative modalities were fundamental to identify each sub-diagnosis alongside excluding differentials. The details differed markedly for each sub-diagnosis. Fifty-nine manuscripts included data on chronic exertional compartment syndrome (CECS) revealing exertional pain (83% history), dull aching pain (76% symptoms), absence of physical signs (78% physical findings) and elevated intercompartment pressure (93% investigative modality). Twenty-one manuscripts included data on medial tibial stress syndrome (MTSS), revealing persistent pain upon discontinuation of activity (81% history), diffuse medial tibial pain (100% pain location), dull ache (86% symptoms), diffuse tenderness (95% physical findings) and MRI for exclusion of differentials (62% investigative modality). Similar analyses were performed for stress fractures (SF, n = 31), popliteal artery entrapment syndrome (PAES, n = 22), superficial peroneal nerve entrapment syndrome (SPNES, n = 15), lumbar radiculopathy (n = 7), accessory/low-lying soleus muscle syndrome (ALLSMS, n = 5), myofascial tears (n = 3), and McArdle's syndrome (n = 2).

CONCLUSION

Initial diagnostic frameworks and definitions have been developed for each condition of the nine most common conditions that cause EILP, suitable for clinical consideration and consensus confirmation.

Risk Factors, Diagnosis and Management of Bone Stress Injuries in Adolescent Athletes: A Narrative Review

Physical activity is known to be beneficial for bone; however, some athletes who train intensely are at risk of bone stress injury (BSI). Incidence in adolescent athlete populations is between 3.9 and 19% with recurrence rates as high as 21%. Participation in physical training can be highly skeletally demanding, particularly during periods of rapid growth in adolescence, and when competition and training demands are heaviest. Sports involving running and jumping are associated with a higher incidence of BSI and some athletes appear to be more susceptible than others. Maintaining a very lean physique in aesthetic sports (gymnastics, figure skating and ballet) or a prolonged negative energy balance in extreme endurance events (long distance running and triathlon) may compound the risk of BSI with repetitive mechanical loading of bone, due to the additional negative effects of hormonal disturbances. The following review presents a summary of the epidemiology of BSI in the adolescent athlete, risk factors for BSI (physical and behavioural characteristics, energy balance and hormone disruption, growth velocity, sport-specific risk, training load, etc.), prevention and management strategies.

Sacral acceleration can predict whole-body kinetics and stride kinematics across running speeds

Background

Stress fractures are injuries caused by repetitive loading during activities such as running. The application of advanced analytical methods such as machine learning to data from multiple wearable sensors has allowed for predictions of biomechanical variables associated with running-related injuries like stress fractures. However, it is unclear if data from a single wearable sensor can accurately estimate variables that characterize external loading during running such as peak vertical ground reaction force (vGRF), vertical impulse, and ground contact time. Predicting these biomechanical variables with a single wearable sensor could allow researchers, clinicians, and coaches to longitudinally monitor biomechanical running-related injury risk factors without expensive force-measuring equipment.

Purpose

We quantified the accuracy of applying quantile regression forest (QRF) and linear regression (LR) models to sacral-mounted accelerometer data to predict peak vGRF, vertical impulse, and ground contact time across a range of running speeds.

Methods

Thirty-seven collegiate cross country runners (24 females, 13 males) ran on a force-measuring treadmill at 3.8-5.4 m/s while wearing an accelerometer clipped posteriorly to the waistband of their running shorts. We cross-validated QRF and LR models by training them on acceleration data, running speed, step frequency, and body mass as predictor variables. Trained models were then used to predict peak vGRF, vertical impulse, and contact time. We compared predicted values to those calculated from a force-measuring treadmill on a subset of data (n = 9) withheld during model training. We quantified prediction accuracy by calculating the root mean square error (RMSE) and mean absolute percentage error (MAPE).

Results

The QRF model predicted peak vGRF with a RMSE of 0.150 body weights (BW) and MAPE of 4.27  ±  2.85%, predicted vertical impulse with a RMSE of 0.004 BW*s and MAPE of 0.80  ±  0.91%, and predicted contact time with a RMSE of 0.011 s and MAPE of 4.68  ±  3.00%. The LR model predicted peak vGRF with a RMSE of 0.139 BW and MAPE of 4.04  ±  2.57%, predicted vertical impulse with a RMSE of 0.002 BW*s and MAPE of 0.50  ±  0.42%, and predicted contact time with a RMSE of 0.008 s and MAPE of 3.50  ±  2.27%. There were no statistically significant differences between QRF and LR model prediction MAPE for peak vGRF (p = 0.549) or vertical impulse (p = 0.073), but the LR model's MAPE for contact time was significantly lower than the QRF model's MAPE (p = 0.0497).

Conclusions

Our findings indicate that the QRF and LR models can accurately predict peak vGRF, vertical impulse, and contact time (MAPE < 5%) from a single sacral-mounted accelerometer across a range of running speeds. These findings may be beneficial for researchers, clinicians, or coaches seeking to monitor running-related injury risk factors without force-measuring equipment.

Evaluating the Clinical Tests for Adolescent Tibial Bone Stress Injuries

BACKGROUND

Tibial bone stress injuries are common among the athletic adolescent population. A thorough patient history and clinical examination are essential to identify the location and extent of injury. However, there has been little description or any validation of clinical tests to help guide clinicians. Consequently, a formal diagnosis is usually dependent on results from proper imaging.

HYPOTHESIS

Clinical examinations will be both highly sensitive and specific determining the incidence, grade, and location of tibial bone stress injury as compared with magnetic resonance imaging (MRI).

STUDY DESIGN

Case-control.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 80 consecutive athletic adolescents, from various sports, with greater than 1-week history of shin pain were enrolled in this institutional review board-approved study. Exclusion criteria were age >19 years and history of traumatic injury. Patients underwent a standardized clinical examination, which included a fulcrum test (FT), tap/percussion test (TT), vibration test (VT) utilizing a 128-Hz tuning fork, weight bearing lunge test (WBLT) to determine degree of dorsiflexion range of motion (ROM), and vertical single leg hop test (VSLHT) for height, landing, and pain. Bilateral lower extremity MRI was completed on the same day as clinical evaluation and served as the injury reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to evaluate each clinical examination for its ability to identify a bone stress injury.

RESULTS

A total of 159 tibiae in 80 patients were evaluated. No single test or combination of tests was both highly sensitive and specific. Individual clinical tests demonstrated sensitivity ranging from 0.11 to 0.72 and specificity ranging from 0.37 to 0.93. The VSLHT noting an increase in pain was the most sensitive test (0.72; 95% CI, 0.62-0.78); however, its specificity was only 0.37 (95% CI, 0.19-0.55), with a PPV of 0.84 (95% CI, 0.78-0.91) and NPV of 0.20 (95% CI, 0.089-0.31). The WBLT demonstrated a mean ROM of 8 cm, with side-to-side differences (range 0-4 cm) not influencing incidence of injury. Combinations of tests demonstrated low sensitivity (0.03-0.40), with better specificity (0.63-1.0). When considering ability to identify higher grades of injury (grade III/IV), all tests had a high NPV indicating that if clinical tests were negative, there was a high likelihood that the patient did not have a grade III or IV injury.

CONCLUSION

No single test or combination of tests was both highly sensitive and specific. Clinicians cannot solely rely on clinical examination for determining extent or severity of bone stress injury in the athletic adolescent population, but when combinations of tests are negative, there is likely not a high-grade bone stress injury.

CLINICAL RELEVANCE

Clinical tests utilized in the evaluation of adolescent tibial bone stress injury may help indicate the presence or absence of higher grade tibial bone stress injury.

Injury Analysis in Professional Soccer by Means of Media Reports - Only Severe Injury Types Show High Validity

Purpose

Injury data of professional soccer players obtained from media reports are frequently used in scientific research, but the accuracy of such data is still unclear.

Patients and Methods

Injuries of professional soccer players of the German first and second league were documented by continuously screening media reports over one season (2015-2016). After the season, the validity of media-reported injuries was anonymously analyzed by the team physicians of 8 different soccer clubs.

Results

A total of 255 injuries of 240 players of 8 professional soccer teams had been published online, of which 146 were confirmed by the team doctors as correct, yielding a rate of 57.3% of confirmed media-reported injuries. In addition, 92 injuries without media registration were detected and added to the online statistics, resulting in 347 injuries and an overall weak validity of media-based data of 42.1%. Statistical analysis showed that the validity of media-reported injury data depended on both the individual soccer club and the body site affected by injury: publications on knee injuries (78.2%) had a higher validity than those on foot injuries (46.2%), and publications on severe injuries had a higher validity (joint dislocation: 100%; ligament rupture: 82.9%; fracture: 73.3%) than those on minor injuries. Publications on specific severe soccer injuries, such as anterior cruciate ligament (ACL) injuries, had a validity of 100%.

Conclusion

Media-based injury data were only valid for a few severe injury types such as ACL injuries. In daily soccer routine and scientific research, media-based data should thus only be used in combination with specific criteria or verification processes.

Validation of the Shin Pain Scoring System: A Novel Approach for Determining Tibial Bone Stress Injuries

Background

The incidence of adolescent overuse injuries, including bone stress injuries (BSIs), is on the rise. The identification of a BSI in the early stages is key to successful treatment. The Shin Pain Scoring System (SPSS) was developed to aid clinicians in identifying patients with a BSI.

Hypothesis

The SPSS will correlate with magnetic resonance imaging (MRI) grading of a BSI in an adolescent population.

Study Design

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

Methods

Enrolled in this study were 80 adolescent high school athletes between the ages of 13 and 18 years participating in a variety of sports with more than 1 week of atraumatic shin pain. The SPSS questionnaire was completed for each participant, and physical examination findings were recorded. Each question and physical examination item was allotted a point value, which totaled 29 points. Radiographs and MRI scans of both lower legs were obtained for each participant. The SPSS score was statistically analyzed using logistic regression, a classification matrix, and a 2 × 2 contingency table to evaluate validity and predictability.

Results

Logistic regression analysis of our data determined that 3 categories of SPSS scores provided the highest diagnostic value when compared with MRI grading based on the Fredericson classification (0-4). The SPSS correctly identified 43.5% of injuries for category 1 (MRI grades 0-1), 62.5% for category 2 (MRI grade 2), and 50.0% for category 3 (MRI grades 3-4). Overall, the SPSS correctly identified the degree of BSI in 54.4% of all tibias studied. Binary analysis for validity demonstrated a sensitivity of 96%, specificity of 26%, positive predictive value of 76%, and negative predictive value of 71% for the SPSS relative to the "gold standard" MRI results.

Conclusion

The SPSS is a potentially valid method to identify tibial BSIs, given the sensitivity and negative and positive predictive values. It also provides helpful categorization to alert clinicians to the presence of a BSI and direct further diagnostics and/or interventions. The SPSS should be considered as an additional tool to use when evaluating adolescents with atraumatic tibial BSIs.

Tc-99m HDP Single Photon Emission Computed Tomography/Computed Tomography in Stress Fracture of Base of Metatarsal Bone

Proximal metatarsal stress fractures are common at base of the second metatarsal, typically seen in repetitive impact athletes, dancers, and those with cavus feet. It is caused by increased bone resorption rather than formation in a state of abrupt increased physical activity or intensity, leading to repetitive microfractures and eventually stress fracture. It is characterized by swelling and tenderness of a prolonged duration. We report a case of a 40-year-old female having left foot pain diagnosed with stress fracture on Tc-99m HDP single-photon emission computed tomography (SPECT)-CT. We emphasize the use of SPECT/CT in allocating active source of pain in the feet.

Magnetic resonance imaging of subchondral insufficiency fractures of the lower limb

Subchondral insufficiency fracture (SIF) is a non-traumatic condition that has historically been associated with elderly, osteoporotic women and patients with systemic conditions. There has been much work done to determine the pathogenesis of SIF, which has previously been regarded as idiopathic, rapid-progressive osteoarthritis or osteonecrosis of the hip, spontaneous osteonecrosis of the knee (SONK), osteochondral defect (OCD) of the talus and adult-onset Freiberg infraction of the metatarsal head. Early diagnosis and management are crucial to prevent subchondral collapse, secondary osteonecrosis and early-onset osteoarthritis. Magnetic resonance imaging (MRI) plays an important role in the diagnosis of SIF, which is often inconspicuous on initial radiographs. In this article, the authors provide an update on the role of MRI in identifying key imaging features of SIF in various joints of the lower limb to aid in its correct diagnosis.

Acute and overuse injuries among sports club members and non-members: the Finnish Health Promoting Sports Club (FHPSC) study

Background

Physical activity in adolescence is promoted for its multi-dimensional health benefits. However, too intensive sports participation is associated with an increased injury risk. Our aim was to compare the occurrence of acute and overuse injuries in Finnish sports club members and non-members and to report training and competing habits associated with a higher injury risk in sports club members.

Methods

In this cross-sectional survey targeted at 14–16-year-old adolescents, a structured questionnaire was completed by 1077 sports club members and 812 non-members. The main outcome measures were self-reported acute and overuse injuries, their location and type.

Results

At least one acute injury in the past year was reported by 44.0% of sports club members and 19.8% of non-members (P < 0.001). The sex-adjusted odds ratio (OR) for acute injury in sports club members compared to non-members was 3.13 (95% confidence interval (95% CI) 2.54–3.87). Thirty-five percent of sports club members and 17.4% of non-members (P < 0.001) reported at least one overuse injury during the past year. The overuse injury OR for sports club members was 2.61 (95% CI 2.09–3.26). Sports club members who trained 7–14 h per week during training (OR 1.61, 95% CI 1.21–2.12, P = 0.001) or competition season (OR 1.55, 95% CI 1.18–2.06, P = 0.002) were more likely to report an injury compared to members who trained 3–6 h per week. Those sports club members who participated in forty competitions or more compared to 7–19 competitions per year were more likely to report an acute injury (OR 1.55, 95% CI 1.05–2.08, P = 0.028) or for an overuse injury (OR 1.53, 95% CI 1.02–2.30, P = 0.038).

Conclusions

Both acute and overuse injuries are common among youth sports club members, and the number increases along with increasing amounts of training and competitions. More effective injury prevention is needed both for adolescents engaging in sports club activities and for other adolescents.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2417-3) contains supplementary material, which is available to authorized users.

Injury Surveillance and Reporting for Trainees with Bone Stress Injury: Current Practices and Recommendations

Background

Musculoskeletal injuries, including lower extremity bone stress injuries (BSI) significantly impact initial entry training (IET) in the U.S. Army due to limited duty days, trainee attrition, early medical discharge, and related financial costs. Factors complicating trainee BSI surveillance include inconsistent BSI coding practices, attrition documentation as both administrative separations and medical discharges and the inability to code for BSI grade or severity when using International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) codes.

Methods

A multidisciplinary expert panel developed policy guidance to enhance clinical and administrative management of BSI, following extensive analysis of current, peer-reviewed literature. Policy guidance incorporates leading practices concerning clinical BSI management, including imaging procedures, recommended notifications, early intervention, and ICD-10 diagnostic coding procedures. Policy guidance also standardizes BSI grading criteria for magnetic resonance imaging and skeletal scintigraphy (bone scan).

Findings

Multidisciplinary expert opinion indicates inconsistent BSI diagnosis and management across IET due to variability in trainee BSI grading, documentation, and coding practices. Injury surveillance conducted by the United States Army Medical Command (USAMEDCOM) will benefit from routine, standardized musculoskeletal injury data base searches by BSI severity/grade and anatomical location upon implementation of BSI policy guidance.

Discussion

Effective injury surveillance is critical for determining trainee BSI incidence and attrition, developing anticipated return to duty (RTD) timelines, and assessing long-term outcomes. BSI RTD timelines should account for gender, BSI grade/severity, anatomical location, and type of intervention. Well-defined RTD timelines would benefit administrative decision-making purposes, including whether to grant convalescent leave or enroll in the Warrior Training and Rehabilitation Program during BSI recovery. Enhanced management procedures may improve initial enlistment completion rates for trainees sustaining at least one BSI who eventually complete IET.

A Review and Proposed Rationale for the use of Ultrasonography as a Diagnostic Modality in the Identification of Bone Stress Injuries

Bone stress injuries are common in military personnel and athletes. The delayed diagnosis of a bone stress injury can lead to a more severe injury that requires a longer period of treatment. The early detection of bone stress injuries is a central part of management. Currently, the reference standard for detecting bone stress injuries is magnetic resonance imaging. However, the expanding use of point-of-care ultrasonography (US) may enable the early detection of bone stress injuries in the clinical setting. In this article, we review the US detection of bone stress injuries, as well as discuss the rationale for the use of US in the diagnosis of these injuries.

Female Athlete Triad: Future Directions for Energy Availability and Eating Disorder Research and Practice

Despite more than 3 decades of research on the Female Athlete Triad, research gaps remain. Although low energy availability (EA) is the key etiologic factor in the Triad and the pathways to low EA are varied, its effects can be modified by several factors. Accurate screening, diagnosis, and treatment of disordered eating are a challenge; however, recent techniques combined with novel educational and behavior interventions prove promising. Recently published practice-based guidelines have helped to translate Triad science and should improve as they are refined. This article identifies the current state of research and distinguishes areas that require further investigation.

Exercise during energy restriction mitigates bone loss but not alterations in estrogen status or metabolic hormones

Energy restriction causes bone loss, increasing stress fracture risk. The impact of exercise during energy restriction on bone and endocrine factors is examined. Exercise with energy restriction did not influence endocrine factors, but did mitigate some bone loss seen with energy restriction in sedentary rats.

INTRODUCTION

Chronic dietary energy restriction (ER) leads to bone loss and increased fracture risk. Strictly controlled trials of long-term ER with and without vigorous exercise are required to determine whether exercise loading can counterbalance ER-induced bone loss. The aim of this current project is to elucidate the impact of exercise and ER on bone mass, estrogen status, and metabolic hormones.

METHODS

Twenty-four virgin female Sprague-Dawley rats (n = 8/group) were divided into three groups-ad libitum fed + exercise (Adlib + EX), 40 % energy restricted + exercise (ER + EX), and 40 % energy restricted + sedentary (ER + SED). Energy availability between ER groups was equal. Treadmill running was performed 4 days/week at 70 % VO2max for 12 weeks.

RESULTS

Fat and lean mass and areal bone mineral density (aBMD) were lower after 12 weeks (p < 0.05) for ER + EX vs Adlib + EX, but ER + EX aBMD was higher than ER + SED (p < 0.0001). Serum leptin and a urinary estrogen metabolite, estrone-1-glucuronide (E1G), were lower at week 12 (p = 0.0002) with ER, with no impact of exercise. Serum insulin-like growth factor I (IGF-I) declined (p = 0.02) from baseline to week 12 in both ER groups. ER + EX exhibited higher cortical volumetric bone mineral density (vBMD) at the midshaft tibia (p = 0.006) vs ER + SED.

CONCLUSION

Exercise during ER mitigated some, but not all, of the bone loss observed in sedentary ER rats, but had little impact on changes in urinary E1G and serum IGF-I and leptin. These data highlight the importance of both adequate energy intake and the mechanical loading of exercise in maintaining bone mass.

Athletic injuries

Injuries are common in the various disciplines that make up the sport of athletics. Diagnosis depends on an accurate history and competent examination, possibly assisted by imaging techniques such as ultrasound, magnetic resolution imaging and computerized tomography. It is also important to consider the influence of various intrinsic and extrinsic factors in deciding on the mechanism of injury. Most acute injuries relate to overstretching of soft tissue, whereas overuse injuries reflect repetitive microtrauma with degenerative or inflammatory consequences. Steroid injections should be restricted to situations where inflammation predominates. Surgery may be required for specific acute injuries and when supervised rehabilitation over 6 months fails to resolve chronic injury. Following surgery, physical and psychological rehabilitation should be carefully planned.

Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners

BACKGROUND

Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture.

METHODS

Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability.

FINDINGS

Heelstrike runners experienced greater impact loading immediately after landing pattern switch (P<0.004). There was an increase in the longitudinal ankle joint contact force when they landed with forefoot (P=0.003). However, there was no significant difference in both peak tibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986).

INTERPRETATION

Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown.

The Relationship Between Landing Sound, Vertical Ground Reaction Force, and Kinematics of the Lower Limb During Drop Landings in Healthy Men

STUDY DESIGN

Controlled laboratory study, cross-sectional.

BACKGROUND

Soft-landing instruction, which is advocated in several injury prevention programs, is thought to have a qualitative relationship with decreased vertical ground reaction forces (vGRFs) and increased lower-limb joint excursions.

OBJECTIVE

To quantify the relationships among landing sound, vGRFs, and lower-limb kinematics during a drop-landing task.

METHODS

Twenty-six asymptomatic men aged 18 to 35 years were asked to perform 15 single-leg drop landings from a 30-cm height. Five trials were collected under 3 sound conditions: normal, quiet, and loud. The vGRF, lower-limb kinematics (sagittal plane), and impact sound were recorded during the deceleration phase.

RESULTS

A simple linear regression revealed a significant relationship between landing sound and vGRF (R(2) = 0.42, P<.001). A repeated-measures analysis of variance showed that ankle and knee excursion significantly increased by 7.0° and 11.7°, respectively, during quiet landing (compared to normal landing; P<.001). During the loud landing condition, ankle joint excursion significantly decreased by 9.4° compared to the normal landing condition (P<.001), and hip joint excursion significantly increased by 4.0° compared to normal landing condition (P<.045).

CONCLUSION

As landing sound decreases, so does vGRF during a drop-landing task. These reductions were achieved by increasing ankle and knee joint excursions. Conversely, as the landing sound increases, so does vGRF. This was the result of decreasing ankle joint excursion and increasing hip joint excursion.

Stress fractures: definition, diagnosis and treatment

Stress fractures were first described in Prussian soldiers by Breithaupt in 1855. They occur as the result of repeatedly making the same movement in a specific region, which can lead to fatigue and imbalance between osteoblast and osteoclast activity, thus favoring bone breakage. In addition, when a particular region of the body is used in the wrong way, a stress fracture can occur even without the occurrence of an excessive number of functional cycles. The objective of this study was to review the most relevant literature of recent years in order to add key information regarding this pathological condition, as an updating article on this topic.

Improving the management of tibia stress fractures: a collaborative, outpatient clinic-based quality improvement project

PURPOSE

Implement and evaluate the effectiveness of the Leg Pain Screening and Referral Tool (LPS&RT) for patients presenting with lower extremity leg pain in an outpatient clinic.

SAMPLE

A total of 46 patients diagnosed with tibia stress fractures.

METHODS

The study employed a pre-/postintervention design. Retrospective and prospective information was collected from an electronic health record to obtain patient data. The pre- and postintervention groups were compared on the number of patients diagnosed with tibia stress fractures. Provider adherence to the treatments recommended by the algorithm was assessed by chart audits postintervention.

RESULTS

There was a significant increase (87.5%) in tibia stress fracture diagnosis, from 16 preintervention to 30 postintervention. Provider adherence to the LPS&RT was 93.3% postintervention. Common treatments were activity restriction, oral medication, and/or specialty referrals.

CONCLUSION

The LPS&RT was an effective, uniform measure to standardize the plan of care for tibia stress fractures in one outpatient clinic.

Magnitude of daily energy deficit predicts frequency but not severity of menstrual disturbances associated with exercise and caloric restriction

We assessed the impact of energy deficiency on menstrual function using controlled feeding and supervised exercise over four menstrual cycles (1 baseline and 3 intervention cycles) in untrained, eumenorrheic women aged 18-30 yr. Subjects were randomized to either an exercising control (EXCON) or one of three exercising energy deficit (ED) groups, i.e., mild (ED1; -8 ± 2%), moderate (ED2; -22 ± 3%), or severe (ED3; -42 ± 3%). Menstrual cycle length and changes in urinary concentrations of estrone-1-glucuronide, pregnanediol glucuronide, and midcycle luteinizing hormone were assessed. Thirty-four subjects completed the study. Weight loss occurred in ED1 (-3.8 ± 0.2 kg), ED2 (-2.8 ± 0.6 kg), and ED3 (-2.6 ± 1.1 kg) but was minimal in EXCON (-0.9 ± 0.7 kg). The overall sum of disturbances (luteal phase defects, anovulation, and oligomenorrhea) was greater in ED2 compared with EXCON and greater in ED3 compared with EXCON AND ED1. The average percent energy deficit was the main predictor of the frequency of menstrual disturbances (f = 10.1, β = -0.48, r(2) = 0.23, P = 0.003) even when weight loss was included in the model. The estimates of the magnitude of energy deficiency associated with menstrual disturbances ranged from -22 (ED2) to -42% (ED3), reflecting an energy deficit of -470 to -810 kcal/day, respectively. This is the first study to demonstrate a dose-response relationship between the magnitude of energy deficiency and the frequency of exercise-related menstrual disturbances; however, the severity of menstrual disturbances was not dependent on the magnitude of energy deficiency.

Medical expenditures in division I collegiate athletics: an analysis by sport and gender

OBJECTIVE

Medical expenses for collegiate athletics include providing a training room with its supplies, equipment, personnel costs, and insurance coverage. Additional expenses beyond the training room include imaging, diagnostic testing, specialty consultations, and surgeries. We hypothesized that there would be no difference in average expenses or number of claims between male and female athletes over a 5-year period.

DESIGN

Prospective patient cohort.

SETTING

A sports medicine center serving athletes in Big 10 Conference intercollegiate sports.

ASSESSMENT OF RISK FACTORS

All medical claims and charges for 36 varsity teams were analyzed from 2005 to 2010. The teams were categorized into 3 groups: female-only teams, male-only teams, and coed teams. Analysis of sports with corresponding male and female teams was also performed.

MAIN OUTCOME MEASUREMENTS

Claims and charges for medical care for 36 intercollegiate athletic teams over 5 years.

RESULTS

Individual team claims and charges were stable over the study period. In 11 of the 14 sex-matched sports, the female teams had higher average annual charges. After normalizing for roster size in the sex-matched sports, females had 0.97 more average annual claims (P < 0.01) and $1459 higher annual charges (P = 0.001) than their male counterparts. The charges per claim were similar between the sexes. The 5 teams with the highest average annual charges were football, wrestling, softball, women's crew, and men's lacrosse. When normalized for roster size, the 5 sports with the highest average annual charges per athlete were softball, women's diving, men's basketball, wrestling, and men's gymnastics.

CONCLUSION

Charges per claim were similar between the sex-matched sports, but the female sports had a higher number of annual claims per athlete and thus higher total charges per athlete/year. Football had the highest average annual total charges as a team, but when normalized for roster size football charges per athlete/year were similar to those of other sports.

Stress at the second metatarsal bone after correction of hammertoe and claw toe deformity: a finite element analysis using an anatomical model

BACKGROUND

We used finite element analysis to evaluate three techniques for the correction of hammertoe and claw toe deformities: flexor digitorum longus tendon transfer (FDLT), flexor digitorum brevis tendon transfer (FDBT), and proximal interphalangeal joint arthrodesis (PIPJA).

METHODS

We performed a finite element analysis of FDLT and FDBT compared with PIPJA of the second toe using multislice computed tomography and 93 tomographic images of the foot obtained in a healthy 36-year-old man.

RESULTS

The PIPJA showed a significantly higher increase in traction and compressive stresses and strain at the medial aspect of the shaft of the second metatarsal bone compared with FDLT or FDBT (P < .01). Mean ± SD compressive stresses increased to -4.35 ± 7.05 MPa compared with the nonsurgical foot (-3.10 ± 4.90 MPa). It can, therefore, be hypothesized that if PIPJA is used to correct the hammertoe and claw toe deformities, it could also increase traction and compressive stresses and strain in the metatarsals during running and other vigorous activities.

CONCLUSIONS

There is a biomechanical advantage to performing FDLT or FDBT instead of PIPJA to surgically treat a hammertoe or claw toe deformity. In addition, tensile strain at the dorsal aspect of the second metatarsal bone when performing PIPJA increases the risk of metatarsalgia or stress fracture in patients at risk.

Forefoot deformation during stance: does the forefoot collapse during loading?

This study presents a specific description of forefoot deformation during the stance phase of normal human walking based on the combined analysis of pressure and three-dimensional optoelectronic measurements. Forefoot deformation is measured in forty healthy subjects using (1) a six-camera motion capture system (sampled at 250 Hz) tracking five reflective skin markers attached to the forefoot, (2) a pressure platform (sampled at 500 Hz) and (3) a forceplate (sampled at 1250 Hz). Forefoot deformation is characterized by the forefoot width, the mediolateral metatarsal arch height and the plantar pressure under the metatarsal heads. Using this setup, a typical pattern of forefoot motion is described during stance phase: From a flexible, compliant configuration at the beginning of stance phase, characterized by a decrease in mediolateral metatarsal arch height and a controlled increase in forefoot width, the forefoot turns into a stable configuration during midstance. Subsequently, the increase in mediolateral arch height and the decrease in forefoot width describe the transformation into a tight configuration during final stance. This transfer from a compliant into a rigid configuration through stance phase rejects the idea of the forefoot as a collapsing structure under increased loading.

MRI of isolated cuboid stress fractures in adults

OBJECTIVE

Isolated cuboid stress fractures are rare. The purpose of this study was to evaluate the MRI appearance of this condition.

MATERIALS AND METHODS

A retrospective search for patients with the diagnosis of a cuboid stress fracture was performed for a 19-year period. All patients underwent an initial three-view radiographic foot series for pain. MRI was performed because symptoms persisted beyond 4 weeks.

RESULTS

Ten patients, nine of whom were women, were diagnosed with isolated cuboid stress fractures. These patients were divided into an athletic group (mean age, 36.3 years) and nonathletic group (mean age, 55.0 years). In the athletic group, there were five runners, one ballet dancer, and one gymnast, and in the nonathletic group, there was one with osteoporosis, one with a plantar fascia rupture, and one who recently underwent a fasciotomy. Eight stress fractures were linear and two were stellate and all were surrounded by marrow edema. Six fractures were located inferolaterally, one superolaterally, one laterally, one medially, and one was subchondral in location. All but one involved the peroneal sulcus and cuboid crest region. Nine of 10 feet showed pathology in the plantar fascia, seven in the peroneal tendons, and four in the posterior tibial tendon.

CONCLUSION

An isolated stress fracture of the cuboid is most likely to occur in the lateral aspect of the cuboid. The cause is likely multifactorial and may include compressive and tensile forces, but plantar fascia dysfunction and age-related bone loss, which are more prevalent in women, may be additional contributing factors.

Clinical reasoning and advanced practice privileges enable physical therapist point-of-care decisions in the military health care system: 3 clinical cases

BACKGROUND AND PURPOSE

Physical therapists frequently make important point-of-care decisions for musculoskeletal injuries and conditions. In the Military Health System (MHS), these decisions may occur while therapists are deployed in support of combat troops, as well as in a more traditional hospital setting. Proficiency with the musculoskeletal examination, including a fundamental understanding of the diagnostic role of musculoskeletal imaging, is an important competency for physical therapists. The purpose of this article is to present 3 cases managed by physical therapists in unique MHS settings, highlighting relevant challenges and clinical decision making.

CASE DESCRIPTION

Three cases are presented involving conditions where the physical therapist was significantly involved in the diagnosis and clinical management plan. The physical therapist's clinical privileges, including the ability to order appropriate musculoskeletal imaging procedures, were helpful in making clinical decisions that facilitate timely management. The cases involve patients with an ankle sprain and Maisonneuve fracture, a radial head fracture, and a pelvic neoplasm referred through medical channels as knee pain.

OUTCOMES

Clinical pathways from point of care are discussed, as well as the reasoning that led to decisions affecting definitive care for each of these patients. In each case, emergent treatment and important combat evacuation decisions were based on a combination of examination and management decisions.

DISCUSSION

Physical therapists can provide important contributions to the primary management of patients with musculoskeletal conditions in a variety of settings within the MHS. In the cases described, advanced clinical privileges contributed to the success in this role.

Determinants of stress fracture risk in United States Military Academy cadets

BACKGROUND

Prior studies have identified some risk factors for stress fracture in athletes and military recruits.

OBJECTIVE

To determine whether historical factors, physical measures, biochemical variables of skeletal metabolism, genetic factors, bone density (BMD) and bone size could predict risk of stress fracture over 4 years in physically fit cadets at the US Military Academy (USMA).

METHODS

Baseline surveys, assessments of height, weight, scores on the Army Physical Fitness Test, and peripheral BMD were obtained in all cadets (755 men, 136 women), and central BMD in a subset. Blood samples were analyzed for variables of calcium homeostasis, bone turnover, and selected hormones and genetic factors. Stress fractures were adjudicated by review of orthopedic notes and imaging reports.

RESULTS

5.7% of male and 19.1% of female cadets had at least 1 stress fracture (58% metatarsal and 29% tibial), most within 3 months of entry to USMA. In males, risk of stress fracture was higher in those who exercised <7 h per week during the prior year (RR 2.31; CI 1.29,4.12), and in those with smaller tibial cortical area (RR 1.12; CI 1.03,1.23), lower tibial bone mineral content (RR 1.11; CI 1.03,1.20) and smaller femoral neck diameter (RR 1.35, CI 1.01, 1.81). In women, higher stress fracture risk was seen in those with shorter time since menarche (RR 1.44 per year; CI 1.19, 1.73) and smaller femoral neck diameter (RR 1.16; CI 1.01, 1.33.).

CONCLUSION

Although prior physical training in men, length of prior estrogen exposure in women and leg bone dimensions in both genders played a role, the maximum variance explained by all of these factors was below 10%. We conclude these factors play a minor role in the development of stress fractures in physically fit USMA cadets.

Femoral neck stress fracture in a female athlete: a case report

OBJECTIVE

The purpose of this case report is to describe chiropractic rehabilitation of a master's-level athlete with proximal femoral stress fracture and provide a brief discussion of stress fracture pathology.

CLINICAL FEATURES

A 41-year-old female master's-level endurance athlete presented with chronic groin pain later diagnosed and confirmed by magnetic resonance imaging as a stress fracture of the femoral neck. After diagnosis, the patient was referred to a doctor of chiropractic at week 1 of the non-weight-bearing physical rehabilitation process. At that time, the patient presented with sharp and constant groin pain rated 6/10 on a numeric rating scale.

INTERVENTION AND OUTCOME

This patient avoided weight-bearing activity for 8 weeks while cross-training and was able to return to her sport after this period. The patient was progressed through a series of non-weight-bearing strengthening exercises for the lower extremity. Myofascial release therapy was performed on the gluteal, hip flexor, and groin muscle groups to improve range of motion. Motion palpation testing the lumbar and sacroiliac joints was performed during each session, and manipulative therapy was performed when necessary. The patient was seen once a week for 8 weeks. Reevaluation was performed at week 8; at that time, the patient reported no groin pain (0/10). The patient was discharged from care and referred back to the supervising physician for clearance to return to sporting activities. One month after discharge, she reported that she was pain free and had fully returned to sport activities.

CONCLUSION

This case report demonstrates the importance of a through clinical history, physical examination, and magnetic resonance imaging in the accurate diagnosis of a patient with chronic groin pain and that chiropractic care can contribute to rehabilitation programs for these injuries.

Stress fractures of the tibia and medial malleolus

Tibial diaphyseal stress fractures are rare in the general population, but are more frequently seen in the athletic and military communities. The diagnosis of this problem may be problematic and needs to be considered in all athletes and military recruits who present with shin or ankle pain. The female triad in athletes (low-energy availability/disordered eating, amenorrhea, and osteoporosis/osteopenia) should be considered in those women who sustain this injury. Management is usually conservative with a variety of rehabilitation programs suggested, but a pragmatic approach is to manage the patient symptomatically.

Lower extremity and pelvic stress fractures in athletes

Stress fractures occur following excessive use and are commonly seen in athletes, in whom the lower limbs are frequently involved. Delayed diagnosis and management of these injuries can result in significant long-term damage and athlete morbidity. A high index of suspicion may facilitate diagnosis, but clinical presentation may be non-specific. In this regard, imaging in the form of plain radiograph, CT, MRI and bone scintigraphy may be of value. This article reviews the incidence, presentation, radiological findings and management options for athletes with stress fractures of the lower limb.

The ability of clinical tests to diagnose stress fractures: a systematic review and meta-analysis

STUDY DESIGN

Systematic literature review and meta-analysis.

OBJECTIVES

To evaluate the diagnostic accuracy of clinical tests to identify stress fractures in the lower limb.

BACKGROUND

Stress fractures are a bone-related overuse injury primarily occurring in the lower limb and commonly affecting running athletes and military personnel. Physical examination procedures and clinical tests are suggested for diagnosing stress fractures; however, data on the diagnostic accuracy of these tests have not been investigated through a systematic review of the literature.

METHODS

A systematic review was conducted in 8 electronic databases to identify diagnostic accuracy studies, published between January 1950 and June 2011, that evaluated clinical tests against a radiological diagnosis of lower-limb stress fracture. Retrieved articles were evaluated using the Quality Assessment of Diagnostic Accuracy Studies tool, and a meta-analysis was performed where appropriate.

RESULTS

Nine articles investigating 2 clinical procedures, therapeutic ultrasound (n = 7) and tuning fork testing (n = 2), met the study inclusion criteria. Meta-analysis was used to statistically analyze the data extracted from the ultrasound articles and demonstrated a pooled sensitivity of 64% (95% confidence interval [CI]: 55%, 73%), specificity of 63% (95% CI: 54%, 71%), positive likelihood ratio of 2.1 (95% CI: 1.1, 3.5), and negative likelihood ratio of 0.3 (95% CI: 0.1, 0.9). Tuning fork test data could not be pooled; however, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio ranged from 35% to 92%, 19% to 83%, 0.6 to 3.0, and 0.4 to 1.6, respectively.

CONCLUSION

The results of this systematic review do not support the specific use of ultrasound or tuning forks as standalone diagnostic tests for lower-limb stress fractures. As the overall diagnostic accuracy of the tests investigated is not strong, based on the calculated likelihood ratios, it is recommended that radiological imaging should continue to be used for the confirmation and diagnosis of stress fractures of the lower limb.

LEVEL OF EVIDENCE

Diagnosis, level 1a-.J Orthop Sports Phys Ther 2012;42(9):760-771, Epub 19 July 2012. doi:10.2519/jospt.2012.4000.

Tibial stress injury: relationship of radiographic, nuclear medicine bone scanning, MR imaging, and CT Severity grades to clinical severity and time to healing

PURPOSE

To examine the relationship between severity grade for radiography, triple-phase technetium 99m nuclear medicine bone scanning, magnetic resonance (MR) imaging, and computed tomography (CT); clinical severity; and recovery time from a tibial stress injury (TSI), as well as to evaluate interassessor grading reliability.

MATERIALS AND METHODS

This protocol was approved by the Griffith University Human Research Ethics Committee, the Stanford University Panel on Human Subjects in Medical Research, the U.S. Army Human Subjects Research Review Board, and the Australian Defense Human Research Ethics Committee. Informed consent was obtained from all subjects. Forty subjects (17 men, 23 women; mean age, 26.2 years ± 6.9 [standard deviation]) with TSI were enrolled. Subjects were examined acutely with standard anteroposterior and lateral radiography, nuclear medicine scanning, MR imaging, and CT. Each modality was graded by four blinded clinicians. Mixed-effects models were used to examine associations between image severity, clinical severity, and time to healing, with adjustments for image modality and assessor. Grading reliability was evaluated with the Cronbach α coefficient.

RESULTS

Image assessment reliability was high for all grading systems except radiography, which was moderate (α = 0.565-0.895). Clinical severity was negatively associated with MR imaging severity (P ≤ .001). There was no significant relationship between time to healing and severity score for any imaging modality, although a positive trend existed for MR imaging (P = .07).

CONCLUSION

TSI clinical severity was negatively related to MR imaging severity. Radiographic, bone scan, and CT severity were not related to time to healing, but there was a positive trend for MR imaging.

Post-operative stress fractures complicating surgery for painful forefoot conditions

A stress fracture is caused by repetitive or unusual loading of a bone leading to mechanical failure. Fatigue type stress fractures occur in normal bone exposed to abnormally high repetitive loads, whereas insufficiency type stress fractures occur in abnormal bone exposed to normal loads. We describe three cases of insufficiency stress fractures that have complicated surgery for painful forefoot conditions. The diagnosis and management of these cases are discussed. Stress fractures should be included in the differential diagnosis of any patient who continues or develops pain after surgery to the forefoot.

Femoral neck stress fractures in military personnel--a case series

Femoral neck stress fractures (FNSF) are uncommon, representing 5% of all stress fractures. In military personnel, FNSF represents one of the more severe complications of training, which can result in medical discharge. Clinical examination findings are often non-specific and plain radiography may be inconclusive--leading to missed or late diagnosis of FNSF This paper highlights the significance of FNSFs in military personnel and alerts physicians to the potential diagnosis. We identified all military recruits, aged 17 to 26, who attended the Infantry Training Centre (Catterick, U.K.), over a four-year period from the 1st July 2002 to 30th June 2006, who had suffered a FNSF. The medical records, plain radiographs, bone scans and MRIs of the recruits were retrospectively reviewed. Of 250 stress fractures 20 were of the femoral neck; representing 8% of all stress fractures and an overall FNSF rate of 12 in 10,000 military recruits. FNSFs were most prevalent amongst Parachute Regiment recruits (1 in 250, p < 0.05). Onset of symptoms was most commonly between weeks 13-16 of training. The majority (17/20, 85%) of FNSFs were undisplaced, these were all treated conservatively. Three FNSFs were displaced on presentation and were treated surgically. Overall, the medical discharge rate was 40% (8/20). FNSFs are uncommon and the diagnosis remains a challenge to clinicians and requires a high index of suspicion in these young athletic individuals. In such individuals early referral for MRI is recommended, to aid prompt diagnosis and treatment and to prevent more serious sequelae.

Review for the generalist: evaluation of pediatric foot and ankle pain

Foot and ankle pain is common in children and adolescents. Problems are usually related to skeletal maturity and are fairly specific to the age of the child. Evaluation and management is challenging and requires a thorough history and physical exam, and understanding of the pediatric skeleton. This article will review common causes of foot and ankle pain in the pediatric population.

Second metatarsal stress fracture in sport: comparative risk factors between proximal and non-proximal locations

BACKGROUND

Stress fractures of the second metatarsal are common injuries in athletes and military recruits. There are two distinct areas in the second metatarsal where stress fractures develop: one proximal (at the base) and the other non-proximal (distal). Diagnosis can be difficult, and there is a difference in prognosis and treatment of the two types of stress fracture. Therefore differentiation of fracture location is warranted. Differences in risk factors and clinical outcomes between proximal and non-proximal stress fractures have not been studied.

OBJECTIVE

To determine whether different risk factors and/or clinical outcomes associated with proximal and non-proximal stress fractures of the second metatarsal exist.

METHODS

Patients diagnosed with proximal stress fractures of the second metatarsal were included in the study. Retrospectively, an age-matched control group with a non-proximal stress fracture was selected for comparison. Statistical analysis involved bivariate comparisons of demographic variables and clinical measurement between the two groups.

RESULTS

Patients with proximal stress fractures were more likely to be chronically affected, usually exhibited an Achilles contracture, showed differences in length of first compared with second metatarsal, were more likely to experience multiple stress fractures, and exhibited low bone mass. In addition, a high degree of training slightly increased the risk of a non-proximal fracture, whereas low training volume was associated with a proximal stress fracture.

CONCLUSION

The signs, symptoms and clinical findings associated with proximal metatarsal stress fractures are different from those of non-proximal stress fractures.

Stress fractures of the second metatarsal base occur in nondancers

Stress fractures of the base of the second metatarsal are common in ballet dancers and essentially are unreported in nondancers. We presumed base of the second metatarsal stress fractures in nondancers occur in a wide variety of individuals regardless of demographics, are highly associated with athletic activities, and have specific examination findings and poor clinical outcomes. Using a retrospective chart review, we identified 12 stress fractures at the base of the second metatarsal (nine patients) in nondancers. Our review suggests second metatarsal base stress fractures occur in nondancers in a diverse population, and nonoperative treatment provides limited success. Advanced radiographic study, specifically MRI, is useful to assist the early diagnosis and prognostication. All of the stress fractures were treated nonoperatively; six fractures (50%) developed nonunion and five underwent subsequent surgery. The surgery for nonunion provided successful outcomes; however, risk factors such as low bone mass and comorbidities may have played important roles in the prognosis.

Return-to-activity levels in 96 athletes with stress fractures of the foot, ankle, and leg: a retrospective analysis

Stress fractures of the foot and ankle are common in the athletic population. Because this population is especially eager to return to activity, such fractures can be challenging to treat. If the biomechanical faults are not addressed or gradual return to activity is not monitored appropriately, fractures occasionally recur. A retrospective analysis was conducted of 96 athletes who presented to a podiatric sports medicine practice over the course of 10 years with stress fractures confirmed by radiograph or bone scan. The most common type of fracture sustained by this population was tibial stress fracture, followed by second metatarsal fracture. Marathon training was the most common pre-injury activity overall, although fitness walking was the most common activity among those with metatarsal fractures. This study relates the most common types of stress fractures of the foot, ankle, and leg to certain athletic activities and correlates duration of symptoms before presentation with return-to-activity time.

Characteristics of Skeletal Stress Fractures in Female Military Recruits of the Israel Defense Forces on Bone Scintigraphy

AIM

Clinical surveys on stress fractures (SF) in female military recruits are scarce. The aim of this study was to characterize the scintigraphic findings and classify the distribution and pattern of SF in a group of female recruits of the Israel Defense Forces (IDF).

MATERIALS AND METHODS

The bone scans of 146 female recruits (age range, 19-20.6 years) with suspected SF were assessed retrospectively. The SF lesions were classified qualitatively into 4 grades of bone response according to the classification criteria introduced by Zwas et al. SF location and distribution were analyzed, and in several cases, the abnormalities were correlated radiographically.

RESULTS

One hundred forty-six female recruits were examined, of which 93 (64%) had bone scan findings of SF with a total of 247 SF. Forty-eight patients (with or without SF) had shin splints, 32 had thigh splints, and 34 had normal scans. Several SF were detected in sites that were not clinically suspected. Thirty-nine percent of the SF were located in the feet (tarsal bones 22.7%, metatarsal 16.2%), 36.8% in tibiae (predominantly in the midthird), 15.7% in femurs, 6.5% in the pubic and sacroiliac regions, and 2% in the fibula. SF in the tibiae and femurs were mainly located in the posterior aspect of the medial cortical region. Forty-nine percent of the patients had bilateral SF. The SF were classified on a 4-grade scale: 41.3% were grade I, 37.2% grade II, 15.8% grade III, and 5.7% grade IV. Thirty-three percent of the patients had one site of SF, 31% had 2 sites, 7.5% had 3 sites, 12% had 4 sites, 7.5% had 5 sites, and 9% had more than 5 sites of SF. Different grades of lesions were often found in the same patient. Sixty-five percent of the patients had SF in the feet, 59% in the tibiae, 26% in the femurs, 14% in the pubic or sacroiliac regions, and 5% in the fibula. Radiography was performed in 15% of the patients. Only one patient had a positive finding on radiography.

CONCLUSIONS

This study shows that lower leg SF are not uncommon in female military recruits. We clearly distinguished between SF and shin splints, which have important clinical consequences on treatment. Most of the SF were mild (grade I and II) located in the feet and tibiae. This study supports the experience gained in other studies, and emphasizes the significant number of pubic and sacroiliac SF in female soldiers, which is significantly higher in comparison with previous reports on male soldiers.

Diagnosis of medial knee pain: atypical stress fracture about the knee joint

STUDY DESIGN

Resident's case problem.

BACKGROUND

A 19-year-old female, currently enrolled in a military training program, sought medical care for a twisting injury to her right knee. The patient reported her symptoms as similar to an injury she incurred 1 year previously while enrolled in the same military program. The patient's past medical history included a nondepressed fracture of the medial tibial plateau and complete tear of the deep fibers of the medial collateral ligament.

DIAGNOSIS

Physical exam revealed nonlocalized anterior and medial knee pain without evidence of internal derangement. Initial knee and tibia radiographs were unremarkable. Referral for orthopedic physician evaluation resulted in concurrence with the therapist's diagnosis and plan of care, and the patient was allowed to continue with limited physical training demands. Despite periods of rest, the patient's symptoms progressively worsened upon attempts to resume running. The examining therapist referred the patient for magnetic resonance imaging (MRI) due to the patient's worsening symptoms, normal radiographs, and concern for a proximal tibia stress fracture. MRI revealed a severe proximal tibial metaphysis stress fracture.

DISCUSSION

Stress fractures are commonly encountered injuries in individuals subjected to increased physical training demands. Early evaluation may not yield well-localized findings and may mimic other conditions. Nonmusculoskeletal conditions should be considered in the management of patients with stress fractures. This resident's case problem illustrates the importance of serial physical examinations and collaboration with other healthcare practitioners in the comprehensive assessment and management of a patient with a severe stress fracture.