Classification of stress fractures of the first rib in adolescent athletes.

Stress fractures of the first rib occur infrequently in adolescent athletes; therefore, there have been few case reports. Initial radiographs do not always lead to the diagnosis of first rib stress fractures. This study proposed a classification system and a possible mechanism for stress fractures of the first rib using three-dimensional computed tomography (3D-CT). The data of 10 stress fractures of the first rib in adolescent athletes obtained using 3D-CT between 2007 and 2018 were reviewed. Fractures of the first rib were classified according to the location and type of the fracture line. Stress fractures of the first rib were classified into three types: type 1, center-transverse fracture; type 2, center to posterior-oblique fracture; and type 3, posterior-transverse fracture. There were three type 1 fractures, five type 2 fractures, and two type 3 fractures. The fracture lines of types 1 and 2 were on the deep groove of the subclavian artery between the anterior and middle scalene muscle attachments, which is the thinnest and weakest portion of the first rib. However, the fracture line of type 3 was across the posterior part of the first rib and located slightly away from the deep groove of the subclavian artery. A 3D-CT classification of stress fractures of the first rib in adolescent athletes was proposed. Our results suggested that there are three types of the fracture and different mechanisms that cause this type of injury. This classification system helped to implement adequate conservative therapeutic plans based on the proposed mechanism.

Estimates of Tibial Shock Magnitude in Men and Women at the Start and End of a Military Drill Training Program.

INTRODUCTION: Foot drill is a key component of military training and is characterized by frequent heel stamping, likely resulting in high tibial shock magnitudes. Higher tibial shock during running has previously been associated with risk of lower limb stress fractures, which are prevalent among military populations. Quantification of tibial shock during drill training is, therefore, warranted. This study aimed to provide estimates of tibial shock during military drill in British Army Basic training. The study also aimed to compare values between men and women, and to identify any differences between the first and final sessions of training. MATERIALS AND METHODS: Tibial accelerometers were secured on the right medial, distal shank of 10 British Army recruits (n = 5 men; n = 5 women) throughout a scheduled drill training session in week 1 and week 12 of basic military training. Peak positive accelerations, the average magnitude above given thresholds, and the rate at which each threshold was exceeded were quantified. RESULTS: Mean (SD) peak positive acceleration was 20.8 (2.2) g across all sessions, which is considerably higher than values typically observed during high impact physical activity. Magnitudes of tibial shock were higher in men than women, and higher in week 12 compared with week 1 of training. CONCLUSIONS: This study provides the first estimates of tibial shock magnitude during military drill training in the field. The high values suggest that military drill is a demanding activity and this should be considered when developing and evaluating military training programs. Further exploration is required to understand the response of the lower limb to military drill training and the etiology of these responses in the development of lower limb stress fractures.

Femoral Neck Stress Injuries: Analysis of 156 Cases in a U.S. Military Population and Proposal of a New MRI Classification System.

OBJECTIVE: The objective of this study is to formulate a new MRI classification system for fatigue-type femoral neck stress injuries (FNSIs) that is based on patient management and return-to-duty (RTD) time. MATERIALS AND METHODS: A retrospective review of 156 consecutive FNSIs in 127 U.S. Army soldiers over a 24-month period was performed. The width of marrow edema for low-grade FNSIs and the measurement of macroscopic fracture as a percentage of femoral neck width for high-grade FNSIs were recorded. RTD time was available for 90 soldiers. Nonparametric testing, univariate linear regression, and survival analysis on RTD time were used in conjunction with patient management criteria to develop a new FNSI MRI classification system. RESULTS: The FNSI incidence was 0.09%, and all FNSIs were compressive-sided injuries. RTD time was significantly longer for high-grade FNSIs versus low-grade FNSIs (p < 0.001). Our FNSI MRI classification system showed a significant difference in RTD time between grades 1 and 2 (p = 0.001-0.029), 1 and 3 (p < 0.001), and 1 and 4 (p = 0.001-0.01). There was no significant RTD time difference between the remaining grades. The rates of completing basic training (BT) and requiring medical discharge were significantly associated with the FNSI MRI grades (p = 0.038 and p = 0.001, respectively). CONCLUSION: The proposed FNSI MRI classification system provides a robust framework for patient management optimization by permitting differentiation between operative and nonoperative candidates, by allowing accurate prediction of RTD time, and by estimating the risk of not completing BT and requiring medical discharge from the military.

Hip arthroscopy enables classification and treatment of precollapse subchondral insufficiency fracture of the femoral head associated intra-articular pathology.

PURPOSE: The purposes of this study were to investigate (1) the clinical, radiographic and arthroscopic presentation of patients with subchondral insufficiency fracture of the femoral head (SIFFH) and (2) the outcomes following arthroscopic treatment with internal fixation using hydroxyapatite poly-lactate acid (HA/PLLA) threaded pins and concomitant arthroscopic treatment of associated findings. METHODS: Nine patients (median age 49.0 years, range 43-65, five female and four male patients) with SIFFH who underwent arthroscopic treatment with labral repair, capsular closure and internal fixation of SIFFH using HA/PLLA pins were retrospectively reviewed. Inclusion criteria were adult patients with precollapse SIFFH with minimum 1-year follow-up (median follow-up 30.0 months, range 12-56). RESULTS: Acetabular labral tears were observed in all patients. The median BMI was 24.3 kg/m2 (range 20.1-31.8). Clinical presentations and radiographic measurements demonstrated mixed type FAI in six patients, borderline developmental dysplasia in two patients and pincer type FAI in one patient. The median MHHS significantly improved from preoperatively (67.1, range 36.3-78.0) to post-operatively (96.8, range 82.5-100; p = 0.001). The median NAHS significantly improved from preoperatively (34.0, range 17-63) to post-operatively (78.0 range 61-80; p = 0.001). CONCLUSION: SIFFH is associated with bony deformities and labral tears. Precollapse SIFFH can be treated with bioabsorbable pin stabilization of unstable lesions and treatment of associated intra-capsular pathology in those with stable lesions as determined by a new arthroscopic classification system with promising early outcomes. LEVEL OF EVIDENCE: IV.

Expected Time to Return to Athletic Participation After Stress Fracture in Division I Collegiate Athletes.

BACKGROUND: Few studies have documented expected time to return to athletic participation after stress fractures in elite athletes. HYPOTHESIS: Time to return to athletic participation after stress fractures would vary by site and severity of stress fracture. STUDY DESIGN: Retrospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: All stress fractures diagnosed in a single Division I collegiate men's and women's track and field/cross-country team were recorded over a 3-year period. Site and severity of injury were graded based on Kaeding-Miller classification system for stress fractures. Time to return to full unrestricted athletic participation was recorded for each athlete and correlated with patient sex and site and severity grade of injury. RESULTS: Fifty-seven stress fractures were diagnosed in 38 athletes (mean age, 20.48 years; range, 18-23 years). Ten athletes sustained recurrent or multiple stress fractures. Thirty-seven injuries occurred in women and 20 in men. Thirty-three stress fractures occurred in the tibia, 10 occurred in the second through fourth metatarsals, 3 occurred in the fifth metatarsal, 6 in the tarsal bones (2 navicular), 2 in the femur, and 5 in the pelvis. There were 31 grade II stress fractures, 11 grade III stress fractures, and 2 grade V stress fractures (in the same patient). Mean time to return to unrestricted sport participation was 12.9 ± 5.2 weeks (range, 6-27 weeks). No significant differences in time to return were noted based on injury location or whether stress fracture was grade II or III. CONCLUSION: The expected time to return to full unrestricted athletic participation after diagnosis of a stress fracture is 12 to 13 weeks for all injury sites. CLINICAL RELEVANCE: Athletes with grade V (nonunion) stress fractures may require more time to return to sport.

Current concepts of shockwave therapy in stress fractures.

Stress fractures are common painful conditions in athletes, usually associated to biomechanical overloads. Low risk stress fractures usually respond well to conservative treatments, but up to one third of the athletes may not respond, and evolve into high-risk stress fractures. Surgical stabilization may be the final treatment, but it is a highly invasive procedure with known complications. Shockwave treatments (ESWT), based upon the stimulation of bone turnover, osteoblast stimulation and neovascularization by mechanotransduction, have been successfully used to treat delayed unions and avascular necrosis. Since 1999 it has also been proposed in the treatment of stress fractures with excellent results and no complications. We have used focused shockwave treatments in professional athletes and military personnel with a high rate of recovery, return to competition and pain control. We present the current concepts of shockwave treatments for stress fractures, and recommend it as the primary standard of care in low risk patients with poor response to conventional treatments.

Classification of Olecranon Stress Fractures in Baseball Players.

BACKGROUND: Although the onset mechanism of an olecranon stress fracture (OSF) due to a throwing disorder is believed to involve valgus extension overload, olecranon posteromedial impingement, or triceps traction force, this issue is still debated in the literature. PURPOSE: To establish a classification system for the different types of OSFs to improve diagnosis and clarify the onset mechanism. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 200 baseball players (198 male, 2 female; mean age, 16.1 years; age range, 13-27 years) who were diagnosed with an OSF from January 1987 to July 2012 were studied. Combined disorders as well as the direction and form of the fracture line were analyzed on plain radiographs, computed tomography, and magnetic resonance imaging. Furthermore, the presence or absence of ulnar collateral ligament (UCL) injuries and avulsion fractures of the lower pole of the medial epicondyle was determined by imaging findings to calculate the combined percentage of OSFs. In addition, the prevalence of OSFs was evaluated among patients who were evaluated between April 2008 and March 2011 for throwing elbow disorders. RESULTS: There were 5 types of OSFs identified in the new classification system: physeal, classic, transitional, sclerotic, and distal. The physeal type was further separated into stages 1 to 4 based on severity. The mean age for each type identified was as follows: physeal, 14.1 years; classic, 18.6 years; transitional, 16.9 years; sclerotic, 18.0 years; and distal, 19.6 years. A concomitant UCL injury and/or medial epicondyle avulsion fracture was diagnosed in 71% to 95% of cases, depending on the OSF type. Among baseball-related elbow disorders, the incidence of OSFs was 5.4%. CONCLUSION: This study presents a new classification system for the different types of OSFs based on the origin and direction of the fracture plane. This new system was strongly influenced by the age at symptom onset. Such information is essential for successful open reduction and internal fixation by ensuring that fixation pressure is perpendicular to the fracture plane, which will avoid the recurrence of stress fractures. In addition, the prevalence of UCL injuries suggests that it is a major risk factor for the development of OSFs.

Clinician approach to diagnosis of stress fractures including bisphosphonate-associated fractures.

Stress fractures are repetitive strain injuries that occur in normal bones and in abnormal bones. Stress fractures share many features in common but differences depend on the status of the underlying bone. This review article for clinicians addresses aspects about stress fractures with particular respect to fatigue fractures, Looser zones of osteomalacia, atypical Looser zones, atypical femoral fractures associated with bisphosphonate therapy and stress fractures in Paget's disease of bone.

The comprehensive description of stress fractures: a new classification system.

BACKGROUND: Stress fractures represent a fatigue failure of bone, occurring with a spectrum of severity of structural injury, and healing potential varies by location. There is no comprehensive classification system for stress fractures incorporating both clinical and radiographic characteristics of the injury that is applicable to all bones. We introduce a system that is reproducible, generalizable, easy to use, and clinically relevant, with three descriptors: fracture grade, fracture location, and imaging modality. METHODS: After a review of current classification systems, a five-tier system was proposed to determine fracture grade: Grade I indicated asymptomatic stress reaction on imaging, Grade II indicated pain with no fracture line, Grade III indicated non-displaced fracture, Grade IV indicated displaced fracture, and Grade V indicated nonunion. Example cases of each grade with clinical vignettes and images were prepared to test the interobserver and intraobserver reliability of the system by the test and retest evaluation among fifteen clinicians. A questionnaire and recall test assessed the ease of use, clinical applicability, and recall accuracy. RESULTS: Test and retest analysis showed that the system had almost perfect agreement in intraobserver reliability with a kappa value of 0.81. The overall intraobserver reliability showed almost perfect agreement with a kappa value of 0.81. Almost perfect agreement with a kappa value of 0.83 was also produced when these responses were compared with our assessment. The overall interobserver reliability had substantial agreement with a kappa value of 0.78. The reliability of the group compared with that of the answer key was almost perfect with a kappa value of 0.83. The recall test showed an overall accuracy of 97.3%. Of the fifteen evaluators who completed questionnaires, fourteen (93.3%) said that the system would be easily remembered, would facilitate communication among colleagues, and would be useful in clinical practice. CONCLUSIONS: The proposed stress fracture classification system is clinically relevant, easily applied, and generalizable, and has excellent interobserver and intraobserver reliability.

Prognostic classification of fifth metatarsal stress fracture using plantar gap.

BACKGROUND: There have been diverse results even in same Torg type of fifth metatarsal stress fractures. METHODS: Eighty-six cases with a fifth metatarsal stress fracture that were treated with modified tension band wiring from January 2003 to May 2009 were evaluated retrospectively. Each case was classified according to Torg's classification and a new classification. Using the new proposed classification, cases were subdivided into complete fracture and incomplete fracture. The cases of incomplete fracture were subdivided based on presence or absence of plantar gap more than 1 mm. After surgery, bone union was determined by CT. Statistical analysis of the Torg classification and time for bone union as well as the proposed new classification and time for bone union was performed. RESULTS: There was a significant difference in the time for bone union among the three Torg types (P = 0.004). The mean time for bone union in group A (complete fracture, n = 32) was 67.5 ± 28.8, and it was 103.2 ± 47.7 for group B (incomplete fracture, n = 54). There was a significant difference in time for bone union between them (P < 0.001). The mean time for bone union in group B1 (incomplete fracture, plantar gap less than 1 mm, n = 16) was 73.9 ± 26.7, and it was 115.5 ± 45.4 for group B2 (incomplete fracture, plantar gap 1 mm or more, n = 38). There was a significant difference in time for bone union between them (P < 0.001). CONCLUSION: The results of this study suggest that the classification incorporating the plantar gap might be used for classification of fifth metatarsal stress fractures. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Stress fractures of the ribs and upper extremities: causation, evaluation, and management.

Stress fractures are common troublesome injuries in athletes and non-athletes. Historically, stress fractures have been thought to predominate in the lower extremities secondary to the repetitive stresses of impact loading. Stress injuries of the ribs and upper extremities are much less common and often unrecognized. Consequently, these injuries are often omitted from the differential diagnosis of rib or upper extremity pain. Given the infrequency of this diagnosis, few case reports or case series have reported on their precipitating activities and common locations. Appropriate evaluation for these injuries requires a thorough history and physical examination. Radiographs may be negative early, requiring bone scintigraphy or MRI to confirm the diagnosis. Nonoperative and operative treatment recommendations are made based on location, injury classification, and causative activity. An understanding of the most common locations of upper extremity stress fractures and their associated causative activities is essential for prompt diagnosis and optimal treatment.

Ultrasound as a primary evaluation tool of bone stress injuries in elite track and field athletes.

BACKGROUND: Little is known about therapeutic ultrasound (TUS) to diagnose bone stress injuries. HYPOTHESIS: Therapeutic ultrasound is an accurate, cost-efficient alternative to other imaging methods for primary assessment of bone stress injuries. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: One hundred thirteen elite track and field athletes (mean age, 20.1 years; range, 17-28 years) underwent TUS and magnetic resonance imaging (MRI) for clinical suspicion of a bone stress injury. A 5-stage MRI grading system was used to classify bone stress injuries. Sensitivity, specificity, accuracy, and positive and negative predictive values of TUS were calculated using MRI as the standard for diagnosis. RESULTS: At MRI, of 113 assessed patients, 3 (2.7%) had grade 0 injuries, 12 (10.6%) had grade 1, 15 (13.3%) had grade 2, 77 (68.2%) had grade 3, and 6 (5.3%) had grade 4. At TUS, no injury was detected in 22 of 113 patients: 2 with grade 0 injury, 8 with grade 1, 8 with grade 2, and 4 with grade 3. Using MRI as the gold standard, TUS showed 81.8% sensitivity, 66.6% specificity, 99.0% positive predictive value, 13.4% negative predictive value, and 81.4% accuracy. CONCLUSION: Therapeutic ultrasound is a reproducible procedure that is reliable to diagnose bone stress injuries.

The non-surgical and surgical treatment of tarsal navicular stress fractures.

Stress fractures of the tarsal navicular, first described in 1970, were initially thought to be rare injuries. Heightened awareness and increased participation in athletics has resulted in more frequent diagnosis and more aggressive treatment. The vascular supply of the tarsal navicular results in a relatively avascular zone in the central one-third, which experiences severe compressive forces during explosive manoeuvers such as jumping and sprinting. Repetitive activities can result in stress reactions or even fracture. Patients often initially complain of vague midfoot pain localized to the medial border of the foot. The pain is usually exacerbated by activity and relieved with rest. The diagnosis of tarsal navicular stress fracture is challenging because of the high false negative rate of plain radiographs. Additional diagnostic testing with bone scan, CT and MRI are often required for diagnosis. The proper treatment of tarsal navicular stress fractures has become a topic of debate as surgical intervention for these injuries has increased. In a recent meta-analysis, Torg et al. found that 96% of tarsal navicular stress fractures treated with non-weight-bearing (NWB) conservative treatment for 5 weeks went on to successful outcomes. However, only 44% of patients treated with weight-bearing (WB) conservative treatment had successful outcomes. Surgical treatment resulted in successful outcome in 82% of patients. Interestingly, the meta-analysis also found that fracture type did not correlate with outcomes, regardless of treatment. The meta-analysis also found no difference in time to return to activity between patients treated surgically and those who underwent NWB conservative treatment. The recent literature indicates that patients are undergoing surgery or are receiving WB conservative management as a first-line treatment option with the expectation that they will return to their activity more quickly. Although surgical treatment seems increasingly common, the results statistically demonstrate an inferior trend to conservative NWB management. Conservative NWB management is the standard of care for initial treatment of both partial and complete stress fractures of the tarsal navicular. WB conservative treatment and surgical intervention are not recommended.

The classification systems of stress fractures: a systematic review.

BACKGROUND: Stress fractures of the upper and lower extremity are troublesome overuse injuries in athletes and nonathletes alike. These injuries have a broad spectrum of severity and prognosis. We performed a systematic search of the literature, which revealed multiple classification systems; however, we did not uncover a general system that offered both validated radiographic and clinical parameters. METHODS: A literature search was conducted using Ovid/Medline, Embase, and the Cochrane Library, with publication dates ranging from 1960 to December 2009. Inclusion criteria included all studies and review articles regarding stress or fatigue fractures and their classification. RESULTS: Forty-three studies and/or articles were identified for this review. Of these articles, 27 classification systems were referenced. Sixteen of the systems were applicable to any injury location, and 1 applied to specific bones (femoral neck, tibia, tarsal navicular, pars interarticularis, and fifth metatarsal). Four classification systems were referenced more often than others. Of the classification systems, 11 were based on radiographs alone, while the other 16 used a variety of radiographic modalities, including radiographs, bone scans, computed tomography, ultrasound, and magnetic resonance imaging. CONCLUSION: There are many different stress fracture classification systems in the literature. These systems employ various imaging modalities, but few include clinical parameters. Many are site specific. Of those that are widely applicable, no general classification system has been shown to be reproducible, easily accessible, safe, inexpensive, and clinically relevant. A gold standard classification system for describing stress fractures has yet to be determined.