跖、趾骨应力的生物力学分析

目的:研究行走状态下跖骨所受应力的大小和分布,为跖骨疲劳性骨折及缺血性坏死的预防及治疗提供参考。方法:采用电阻应变测试方法,使用YD-21型动态电阻应变仪,进行跖骨应力测试与力学模型计算。结果:第2跖骨承受地面压力最大,且第2跖骨承受最大弯曲应力及最大的剪力;第1跖骨承受的轴向力最大。提示第2跖骨承受的最大弯曲应力可能是该骨疲劳性骨折及缺血性坏死发生的主要原因。     

股骨颈疲劳骨折2例报告

疲劳性骨折又称为应力性骨折,多见于跖骨和胫骨,但股骨颈骨折则不多见。1978年以来,我院收治般骨颈疲劳骨折2例,现报告如下。     

股骨颈疲劳性骨折9例临床分析

疲劳性骨折在部队训练中较为常见 ,好发于胫骨和第二跖骨 ,但股骨颈疲劳性骨折发生率极低 ,临床上鲜有报道。我科自 1993年 2月～ 2 0 0 3年 3月共收治股骨颈疲劳性骨折患者 9例 ,现报道如下。1　资料和方法1.1　一般资料　本组 9例 ,均为男性新兵 ,年龄 17～ 2 0岁 ,平均 18.6     

(足母)外翻及正常足部的X线测量分析

目的 :通过外翻 (HV)和正常足部的X线测量分析 ,探讨外翻的发病机制及临床意义。方法 :对 118例正常人中 12 1足和 5 1例HV病人中 5 6足的外翻角 (HVA)、1～ 2跖骨间角、1～ 5跖骨间角和第 1跖骨长度与趾长度之比率进行测量 ,将测量数据进行统计学处理。结果 :正常足和HV病人测量结果分别为 :HVA 11.32°± 7.11°和 2 7.31°±6 0 3°,1～ 2跖骨间角 7.5 0°± 3.2 1°和 10 .2 1°± 3.5 6° ,1～ 5跖骨间角 2 1.80°± 7.6 0°和 2 7.92°± 9.80°,第 1跖骨长度与趾长度比值 1.13± 0 .0 9和 1.16± 0 .13。正常足男、女之间各种角度无统计学差异 (P >0 .0 5 ) ,正常足与HV病人的HVA、1～ 2和 1～ 5跖骨间角均有显著性差异 (P <0 .0 0 0 5 ) ,第 1跖骨长度与趾长度比值无差异 (P >0 .0 5 )。结论 :HV病人的首要X线表现为HVA增大 ,1～ 5跖骨间角增大是发生HV的主要基础 ,1～ 2跖骨间角增大是继发改变。HVA >2 0°,1～ 2跖骨间角 >10°是诊断和治疗HV的重要客观指标。     

双足对称跖骨疲劳骨折1例

双足对称跖骨疲劳骨折１例武警新疆总队医院放射科蔡都放（乌鲁木齐８３００００）关键词疲劳骨折双足对称跄骨同时发生疲劳骨折很少见,伴＊跖骨多发疲劳骨折就更为少见。我科遇到１例,现报告如下。＊患者,女,战士,１９岁。新兵训练结束后,＊主足跄部肿胀,疼痛,行...     

青少年疲劳性骨折的影像诊断

疲劳性骨折 (以下简称疲劳骨折 )易发生在第二、三、四跖骨 ,其次为胫腓骨近端及股骨的远三分之一段 ,发生在青少年的疲劳骨折未见有系统报道 ,本文就我院资料完整的青少年疲劳骨折 8例临床表现、Ｘ线平片、ＣＴ、ＭＲＩ表现进行分析比较 ,并简要提出鉴别诊断。1　材料和方法1     

肋骨疲劳骨折两例报告

疲劳骨折亦称应力骨折,可发生于全身许多骨骼,但以跖骨为多见,发生于肋骨者较少。现将2例因剧烈咳嗽而致肋骨疲劳骨折报告如下。例1 男,50岁。因咳嗽、右胸背痛10余天于1978年1月28日就诊,患者曾有多年右上肺结核史,时有轻咳。近三周来咳剧,痰多而不易咳出,并感胸痛气急乏     

新兵应力性骨折的发生与防治

应力性骨折（siress fracture SF）亦称疲劳性骨折，是军事训练、运动员训练中的常见损伤。其发病率各家报道不同，美国海军陆战队新兵发病率为2．9％，以色列新兵高达31％。国内报道新兵应力性骨折发病率为9．5％～16．9％，个别报道甚至高达32．5％。应力性骨折好发于下肢，不同运动引起的应力性骨折部位各异，比如，篮球运动员的跗、跖骨发病率较高，田径运动员多发于胫骨、腓骨或跖骨，足球运动员好发第5跖骨。部队军事训练中，以负重行军和长跑训练引起的胫骨应力性骨折最为多见（50％-80％）；其次为跖骨（20％～40％）。     

凝视手机对青年女性行走时足底压力及下肢表面肌电的影响

目的:探讨凝视手机对青年女性行走时足底压力及下肢表面肌电的影响。方法:运用Footscan高频足底压力测试系统和BTS FREEEMG300型号的32导无线表面肌电系统对16名青年女性正常行走与凝视手机行走进行测量,比较两种状态步行过程中步长、跨步长、步宽,足底各区域压力峰值、接触面积、冲量、足着地过程时相及均方根振幅等指标的变化。结果:青年女性凝视手机行走改变了正常行走步态特征,主要表现在步长变短、步宽变小(P<0.05)、前掌接触阶段和整足接触阶段所占支撑期的百分比增加(P<0.05);低头凝视手机行走时足底第3跖骨、第4跖骨和足跟外侧区域的峰值压力高,与地面接触面积大(P<0.05));与正常行走相比,凝视手机行走足底第3跖骨、第2跖骨、第1跖骨所受冲量较大(P<0.05);凝视手机行走步态周期不同时相的下肢各肌肉参与程度较低。结论:凝视手机行走使用了更为谨慎的步态;凝视手机行走容易导致足底出现疲劳和损伤;凝视手机行走时神经肌肉的控制程度减弱。     

应力性骨折的影像学诊断进展

应力性骨折（stress fracture SF）亦称疲劳性骨折，是军事训练、运动员训练中常见的损伤。其发病率各家报道不同，美国海军陆战队新兵的发病率为2．9％，以色列新兵高达31％。国内报道，新兵应力性骨折发病率为9．5％～16．9％，个别报道高达32．5％。应力性骨折好发于下肢，不同运动引起的应力性骨折部位各异，比如，篮球运动员的跗、跖骨发病率较高，田径运动员多发于胫骨、腓骨或跖骨，足球运动员好发于第5跖骨。部队军事训练中，以负重行军和长跑训练引起的胫骨应力性骨折最为多见（50．0％～80．0％），其次为跖骨（20．0％～40．0％）。     

99mTc-MDP bone scintigraphy in the diagnosis of stress fracture of the metatarsal bones mimicking oligoarthritis

BACKGROUND: Stress fractures are the injuries of soft tissues and bones caused by intensive and repeated stress on a bone. Repeated submaximal stress disturbs the balance between the processes of bone production and resorption that results in fracture. CASE REPORT: We presented a case of a patient with stress fracture of metatarsal bone. The patient was diagnosed and treated as having reactive oligoarthritis caused by Chlamydia trachomatis and administered antibiotics. Initial plain radiography was negative for bone fracture. Tc-99m bone scintigraphy suggested stress fracture of the second metatarsal. Plain radiography was became positive three weeks later, showing callus formation in the proximal part of the second metatarsal. CONCLUSION: Bone scintigraphy is a diagnostic test of choice in early diagnosis of stress fracture, and it is important to apply it timely in order to include the entire therapy and prevent complications, as well as to let a patient return to previous daily activities.     

A mechanical model of metatarsal stress fracture during distance running

A model of metatarsal mechanics has been proposed as a link between the high incidence of second and third metatarsal stress fractures and the large stresses measured beneath the second and third metatarsal heads during distance running. Eight discrete piezoelectric vertical stress transducers were used to record the forefoot stresses of 21 male distance runners. Based upon load bearing area estimates derived from footprints, plantar forces were estimated. Highest force was estimated beneath the second and first metatarsal head (341.1 N and 279.1 N, respectively). Considering the toe as a hinged cantilever and the metatarsal as a proximally attached rigid cantilever allowed estimation of metatarsal midshaft bending strain, shear, and axial forces. Bending strain was estimated to be greatest in the second metatarsal (6662 mu epsilon), a value 6.9 times greater than estimated first metatarsal strain. Predicted third, fourth, and fifth metatarsal strains ranged between 4832 and 5241 mu epsilon. Shear force estimates were also greatest in the second metatarsal (203.0 N). Axial forces were highest in the first metatarsal (593.2 N) due to large hallux forces in relationship to the remaining toes. Although a first order model, these data highlight the structural demands placed upon the second metatarsal, a location of high metatarsal stress fracture incidence during distance running.     

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.     

Less common stress fractures in the foot

In a series of 827 stress fractures in soldiers, 15 were found in the first metatarsal, representing 11% of all stress fractures in the metatarsals. All were in the proximal end of the bone. Eight fractures were found in the fourth and four in the fifth metatarsal. In the cuneiform bones three fractures were found, and one in the talus. One fracture was revealed in the lateral sesamoid of the hallux and one in the peroneal bone. Ten patients had stress fractures in other bones too. The radiological appearance and the corresponding stress mechanisms are discussed.     

Foot and ankle fractures in dancers

Fractures in the dance population are common. Radiography, CT, MRI, and bone scan should be used as necessary to arrive at the correct diagnosis after meticulous physical examination. Treatment should address the fracture itself and any surrounding problems such as nutritional/hormonal issues and training/performance techniques and regimens. Compliance issues in this population are a concern, so treatment strategies should be tailored accordingly. Stress fractures in particular can present difficulties to the treating physician and may require prolonged treatment periods. This article addresses stress fractures of the fibula, calcaneus, navicular, and second metatarsal; fractures of the fifth metatarsal, sesamoids, and phalanges; and dislocation of toes.     

Three-dimensional ankle kinematics and kinetics during running in women

Stress fractures are common in athletics and are more prevalent in women. The current literature has not identified a reason for this gender difference. We hypothesized that females with a history of a second/third metatarsal stress fracture will demonstrate differences in ankle kinematics, kinetics and ground reaction forces when compared with a group of age-matched females with no stress fracture history. A total of 15 control females and nine females with a history of a second/third metatarsal stress fracture were asked to run at 3.3 m/s ± 5% along a 10-m runway. Kinematics and kinetics were obtained using an 8-camera motion analysis system (240 Hz) and two force plates (1200 Hz).Significant differences existed in height and weight between the groups. No other statistically significant differences existed between the fracture group and the control group. Kinematic measurements do not differ significantly between women with a history of second/third metatarsal stress fracture and female control subjects. The reported kinematic and kinetic measurements do not appear to be influenced in subjects with metatarsal stress fractures, which likely result from the complex relationships between the joints in the foot and ankle. The development of second/third metatarsal stress fractures could result more from over training or changes in plantar loading instead of changes in lower extremity joint kinematics while running.     

Metatarsal shaft fractures and fractures of the proximal fifth metatarsal

Metatarsal fractures represent a relatively common injury, especially in athletes. The pertinent anatomy, evaluation, diagnosis, classification, and treatment of acute and chronic (stress) metatarsal shaft fractures are discussed. Fractures of the proximal fifth metatarsal, which are unique and important injuries, are also discussed. Treatment remains relatively straightforward for the traumatic metatarsal injury, whereas traditional stress fractures typically heal with decreased activity. The problematic proximal fifth metatarsal fracture (Jones fracture) frequently requires surgical intervention in patients who want to avoid non-weight-bearing cast immobilization. The authors' current treatment for this fracture includes the option of intramedullary fixation versus cast immobilization.     

Stress fractures of the lateral metatarsal bones in metatarsus adductus foot deformity: a previously unrecognized association

Objective. To document a distinctive pattern of stress fractures in the lateral metatarsal bones of patients with metatarsus adductus foot deformity. Design and patients. Conventional radiographs and available medical records were reviewed in 11 patients (6 women, 5 men; ages 25–61 years) with stress fractures of the lateral (fourth or fifth) metatarsal bones and metatarsus adductus. Evaluation included the number and location of fracture(s), forefoot adduction angle, and qualitative assessment of bone mineral density. Conditions that might predispose patients to metatarsal fractures, including direct trauma, osteoporosis, and neuropathic osteoarthropathy were also recorded. Results. A total of 22 stress fractures were demonstrated, 17 of which involved the lateral metatarsals. A solitary fracture was present in six patients, while multiple fractures were evident in five patients. The sites of involvement were the fifth metatarsal (n=10), fourth metatarsal (n=7), third metatarsal (n=3), second metatarsal (n=1), and first metatarsal (n=1) bones. The locations of the stress fractures were in the proximal one-third of the metatarsal bones in 19 instances (86%) and in the middle one-third in three instances (14%). Forefoot adduction angle measured between 21° and 37° (normal range 8°–14°). Conclusion. Patients with metatarsus adductus may be at increased risk for stress fractures involving the lateral metatarsal bones, likely owing to the presence of altered biomechanics that place greater loads across the lateral aspect of the foot. Received: 27 May 1999 Revision requested: 29 July 1999 Revision received: 23 August 1999 Accepted: 26 August 1999     

Drummer's fracture of the third metatarsal bone

A 14-year-old girl presented with a painful right foot. She was an elite water-polo player and could recall no history of specific trauma to the foot. On close and persistent questioning, she admitted to having taken up playing the drums recently, with practice sessions of up to 4 h/d. She used the foot drum with her right foot and had noticed that this was becoming increasingly painful and prevented her playing the instrument for the last 2 days. Plain films of the foot were originally reported as normal, but revised to abnormal after the scintigraphic study. Bone scintigraphy confirmed a stress fracture of the right 3rd metatarsal bone. Stress fractures of the 3rd metatarsal bone are rare with only 2 previous reports in the literature.