139 Due to the relatively short follow-up period (12 weeks) maturation is unlikely to have influenced the findings (Meiring et al., 2014). Despite significant genotype dependent differences observed in bone phenotypes, such as cortical thickness, CSA and density, it is unclear whether these differences are clinically significant in terms of heightened susceptibility to bone injury. Lower BMD (Wentz et al., 2012), cortical CSA (Popp et al., 2009) and cortical thickness (Newsham-West et al., 2013) have all previously been associated with stressfracture injury, although these associations were not made in adolescent footballers. As sports and activities have different levels of loading caused by differences in training and match-play, bone phenotypic differences have also been shown to occur (Please see section 2.3.2.). Therefore, an injury risk threshold for bone phenotypes is yet to be characterised in this specific population. Only the tibia was assessed in the present study and so, the bone changes shown cannot be generalised to changes in bone structure at other anatomical locations. However, by using pQCT, important differentiations between cortical and trabecular bone could be made, clarifying the specific impact football training has on the components of bone. Due to the number of comparisons made, there is a possibility that the findings occurred by chance, however as the majority of the results are in the same direction as previously published literature and a mechanistic explanation can be offered, the chances of a type II error are unlikely.
prevalence of menstrual dysfunction (1-44%) (Bennell et al. 1997b) and disordered eating (1-62%) (Sundgot-Borgen and Torstveit 2007). Low bone density has been identified as a potential risk factor in some (Bennell et al. 1996a; Kelsey et al. 2007; Nattiv 2000) but not all studies (Bennell et al. 1995; Carbon et al. 1990; Grimston et al. 1991; Myburgh et al. 1990)(Chapter 4 and chapter 6) in female athletes. In previous studies, however bone mineral density was not measured at the time of stressfracture diagnosis, therefore it may be feasible that changes in bone mineral density following a stressfracture could contribute to reoccurrence of stressfracture by reducing the bone strength (Bennell et al. 1999), resulting in an accumulation of micro-damage when athletes begin retraining following injury (Caler et al. 1981). Sudden increases or changes in training intensity and volume have previously been associated with increased risk of stressfracture (Brunet et al. 1990; Goldberg and Pecora 1994; Shaffer 2001). It is well established that there is an association between fracture and low bone mineral density, therefore clinically accurate BMD measurements can predict the likelihood of a fracture (Cummings et al. 1993; Melton et al. 1993). However, in athletes BMD tends to be above the level seen in the average population due to the increased mechanical loading (Bennell and Brukner 2005b) (Kannus et al. 1994a; Khan et al. 2001; Nordstrom et al. 2005b). There are no normative BMD databases for athletes with which to determine potential low bone mass. Similarly there is no indication of whether bone changes following stressfracture are associated with reoccurrence rates.
In this report, a proximal humeral stressfracture was described in a young woman, with contralateral humeral bone marrow edema probably due to mechanical overload during CrossFit practice. Also, there was bilateral subsca- pularis muscle edema, related to DOMS and was consid- ered to be a contributor to bilateral shoulder pain, without tears. The imaging findings of shoulder MRI and negative radiographs were key to diagnosis this condition and ex- cluded other possible causes of upper extremity pain, such as rotator cuff injury. We considered that female gender, and vitamin D insufficiency associated with extreme train- ing routine were possible predisposing factors for this un- common proximal humeral stressfracture. Analgesia and joint rest may lead to resolution of symptoms and fracture healing. If necessary, vitamin D supplementation and monitoring, as well as bone mineral density assessment should be recommended, to prevent further fractures. Follow-up radiographs and MRI are useful to monitor bone consolidation and possible complications. Further studies are necessary to define potential risks to shoulder
Family history was obtained by subject self-report via a semistructured health history interview. For each first- degree relative (mother, father, and siblings) and select second-degree relatives (maternal and paternal grand- parents), the participant was asked whether the family member had a history of stressfracture (possible re- sponses included “yes,” “no,” or “don’t know”) and at what age it was diagnosed. She was similarly asked about the family members’ history of osteoporosis, then separately about their history of osteopenia. To account for the families’ potential lack of access to their relatives’ medical charts, participants were additionally asked about the individual relatives’ histories of frequent frac- tures or “brittle bones” (to identify potentially un- measured, and therefore undiagnosed, low bone mass) without the specific date of diagnosis. Parents who ac- companied the participants were allowed to assist their daughters in answering the family history questions. We created 3 classifications for family history on the basis of participant responses to these 4 questions. A positive response for osteopenia or osteoporosis diagnosed in a family member (siblings, parents, or grandparents) was categorized as a positive “measured family history,” be- cause these conditions are often quantified radiograph- ically. A positive response for stressfracture or other frequent fractures was considered a positive “family his- tory of fracture.” Positive responses to any of these 4 conditions were combined into a general “positive family history.”
MRI showed linear abnormal signal with peripheral bone marrow edema and bruising in the medial aspect of the right femoral neck is suggestive for stressfracture also mild amount of effusion in the right hip joint and mild soft tissue edema at the anterior and posterior aspect of right femoral neck was shown (figure 3). The patient was advised to go through internal fixation but she declined this plan. The patient received subcutaneous injections of 20 mcg Teriparatide (CINNOPAR) for 6 weeks. Pelvic spiral CT- scan after 1 month showed no healing (Figure 4). She came back to the orthopedic clinic about 3 months later without any pain or limitation of motion .bone healing was confirmed in hip spiral CT scan (Figure 5). She described her treatment as 1 month of complete bed rest and the unrestricted but cautious activity afterwards .The patient gave informed consent prior to being included into the study.
While taxiing to the gate the spoilers were lowered and the flaps were retracted, the latter into the wing. This is undoubtedly standard operating procedure which, in this case, hides the stressfracture. Thus, it would not be seen by ground service personnel or by the pilot during a “walk around” inspection with flaps up prior to departure of the next flight. That procedure needs to be reviewed. But it is questionable if the damage could be seen from ground level looking up because of its high position on the flaps. Although readily visible from seats over the wing, at ground level one may need to step back a bit to view it, like geologists and geophysicists do when we are looking at seismic cross sections.
The proximal femur can suffer stress fractures in a number of sites. Femoral neck fractures are perhaps best known but they can be radiographically subtle in the early stages, and in activity-related pain with negative radiographs further imag- ing workup with MRI is indicated. The typical femoral neck stressfracture is located on the medial aspect and perpendic- ular to the stress lines and the femoral neck (Fig. 3). They are due to compressive forces and seen more in younger, more athletic patients. Femoral neck fractures on the craniolateral aspect of the femoral neck are more common in older patients. These fractures are due to distraction; the risk of non-union is higher than for the medial compression fractures although for both types the risk of non-union is relatively high compared with other sites [13, 14, 16, 19].
In contrast, there was evidence for an association between the Wnt signalling pathway and microdamage. osteocytes regulate bone formation, primarily via their production of the Wnt signalling protein sclerostin, which inhibits bone formation 15 and responds to local load. 16 We have identified sclerostin protein in osteocytes in all the samples we have studied, especially along the fractured line, where there was a marked and significant increase in sclerostin-positive osteocytes, which was unexpected. In rat ulnar models of a stressfracture, scle- rostin has been reported to be reduced adjacent to the fracture line, 37 although these were acute experiments. The finding that osteocyte apoptosis is not associated with equine microdamage, but is associated with rat ulnar microdamage, suggests that microdamage in the racehorse has a fundamentally different pathological pro- cess to that of small animals.
Despite these positive aspects, some authors have reported no advantages along with a longer operative time with the use of computer-assisted systems [7, 8]. Moreover, recently three cases of stress femoral or tibial fractures have been reported as a complication of navigated TKA [9, 10]. We present a case of a stressfracture of the tibial diaphysis which occurred after a TKA performed with the use of a computer navigation system. The stressfracture occurred at one of the pinhole sites used for the placement of the tibial trackers.
Our results showed that both the kinematics and kin- etics of the hip changed substantially during running with load carriage. When compared with the baseline condition, carrying a 30% BW load decreased the mean peak hip extension at toe off by 54.7% and increased the mean peak hip flexion and extension moments by 10.0% and 62.5%, respectively, in addition to increasing the mean peak hip JRFs (49.1%, Table 1). These results high- light the importance of hip muscles in high-intensity physical activity (e.g., running with load carriage), and are supported by previous studies linking them with sports injuries. For example, in collegiate female athletes with patellofemoral injury, hip abductors and external rotators are significantly weaker in the injured leg than in the unaffected leg . Furthermore, if the hip exten- sors do not generate enough power, either other muscles in the lower extremities will compensate for the reduced force, or movement patterns will change, which in turn may result in increased energy costs and early muscle fa- tigue . Such changes may be related to a number of biomechanical alterations that potentially increase the risk of impact-related injuries in the lower extremities (e.g., Achilles tendinosis, patellofemoral dysfunction, and tibial stressfracture) . Preparatory strength and en- durance training exercises before military BCT, such as squats, incline sit-ups, leg raises, and interval training, which are designed to strengthen hip flexor muscles and pelvic-stabilizing muscles (gluteus medius), are effective in assisting prospective Service members to endure BCT without injuries .
There is a subset of high-risk stress fractures that have a tendency toward progression to complete fracture, de- layed union, nonunion, and chronic pain, but fibula stressfracture is in the low-risk group and in the literature, no cases were found with hypertrophic nonunion of fibula di- aphysis following stressfracture.
Stress fractures are classified as low-risk or high-risk. As low-risk fractures are compression stress fractures, they can recover with conservative treatment. They are generally seen in the femoral shaft, the medial tibia, the fibula, calcaneus and first and fourth metatarsals. As the high-risk stress fractures are tension-typed , surgical intervention is generally required. Delayed union and non-union may be seen in this type of fracture. They are generally seen in the 5 th metatarsal, the anterior tibia, the tarsal navicular bone, the femoral neck, the patella and the 1 st metatarsal sesamoid bone   . According to this classification, the current patient should be eva- luated as a low-risk stressfracture.
Case Report: A 23-year-old, right-handed, cricket batsman presented with pain in the hypothenar region of his left hand of 7 weeks duration. The pain typically worsened during batting, and he had difficulty in gripping the bat. Plain radiographs were largely inconclusive; magnetic resonance images, however, demonstrated a stressfracture of the hamate hook. The patient was put on conservative management, and his bat grip was modified. He recovered completely within 12 weeks and went back to playing professional cricket.
The subjects included 84 elite university lacrosse players (Table 1). Before the study, we questioned subjects regarding past medical history of stressfracture, which was diagnosed by experienced orthopedic surgeons. All subjects were instructed to base their answers on their past status in our original questionnaire. Based on this investigation, subjects were divided into groups with (5 males and 7 females)
Methods: 52 athletes (female, n = 30; male, n = 22; mean age, 22.8 years) with stressfracture (SFX) who had undergone at least one examination, either MRI or bone scintigraphy, were included. Magnetic resonance images (MRI) and/or bone scintigraphy (BS) of SFX were classified as either low- or high-grade SFX, according to existing grading systems. For MRI, high-grade SFX was defined as visibility of a fracture line or bone marrow edema in T1-, T2-weighted and short tau inversion recovery (STIR) sequences, with low-grade SFX showing no fracture line and bone marrow edema only in STIR and/or T2-weighted sequences. In BS images, a mild and poorly defined focal tracer uptake represented a low-grade lesion, whereas an intense and sharply marginated uptake marked a high-grade SFX. In addition, all injuries were categorized by location as high- or low-risk stress fractures. RTST was obtained from the clinical records. All patients were treated according to a non-weight-bearing treatment plan and comprehensive follow-up data was complete until full recovery. Two-sided Wilcoxon ’ s rank sum test was used for group comparisons.
However, even after completing a graduated rehabilita- tion programme and having returned to previous level of competitive football, the MT-5 injured players examined here displayed large differences in plantar loading at the lateral foot. These data should implore practitioners to exercise a high index of suspicion should prodromal symptoms occur in a player with history of previous MT-5 stressfracture and manipulate football movements accordingly.
One retrospective study had found that 8.3% to 52% of runners have had a history of stressfracture, although whereas the incidence in a 12-month prospective study of track and field athletes the incidence was 21.1% (Warden, Burr & Brukner, 2006). When expressed as a
percentage of all injuries, stress fractures have been reported to represent between 0.5% and 20% of all injuries sustained by athletic populations (Warden, Burr & Brukner, 2006). Prevention is key and the only way to prevent this type of injury is to recognize the predisposing risk factors. In their 2007 consensus statement, the American College of Sports Medicine stated that the recognition of risk factors associated with stress fractures is of paramount importance. It is imperative to note that stress fractures are not the result of one individual cause but of multiple causes. Results from studies of female or female and male athletes are contradictory regarding the associations of stress fractures with age, lower bone mineral density or lean body mass, late age at menarche, use of oral contraceptives, low body weight, disordered eating, and low calcium and dairy product intake. Individual studies have reported leg length discrepancy, low dietary fat intake, and a history of stressfracture to be risk factors, but confirmation in other investigations is needed (Kelsey et al, 2007). Nutritional deficits additionally compromise bone and increase the susceptibility to fractures (Bennell, 1996). Athletes represent an important population to evaluate for dietary and activity factors related to bone growth and development because they are often of high school or college age and at least 90% of peak bone mass is attained by age 18 (Tenforde et al, 2010).