A stress fracture should be suspected clinically when the patient gives a typical history of pain during exercise.
Clinical examination is usually not reliable, and the diagnosis should be confirmed with imaging studies (x-ray, magnetic resonance imaging).
An early identification is especially important in those stress fractures where a dislocation would necessitate surgical management and thus prolong recovery period.
Risk of dislocation is associated, in particular, with femoral neck and shaft fractures. A femoral stress fracture should be suspected in military conscripts and those involved in strenuous exercise who complain of groin, hip, thigh or knee pain, however mild.
In order to avoid complications, the patient must be told not to engage in any activities associated with repetitive loading until a stress fracture has been excluded.
Risk groups
Military conscripts (2-15%)
Most cases occur during the first three months of military training.
Women
Female athletes and female military conscripts have a 2-10-fold risk compared with their male counterparts.
Eating disorders and menstruation disturbances also predispose to stress fractures.
Athletes and dancers and those who have recently started intensive physical training.
Unusually strenuous walking or running exercises.
Location of stress fractures
The most common sites for stress fractures are the pelvic region and lower limbs (weight bearing bones)
Stress fractures of the upper limbs are rare
· The most common sites of stress fractures in military conscripts: see T1
Sites of stress fractures in military conscripts
Site
% of all stress fractures
Tibia
50-70
Metatarsals
20
Calcaneus
8
Femoral bone
5-10
Pelvic bones
4
Symptoms
Initially the pain occurs only during exercise, and later also at rest.
Pain is often local.
In superficial bones, the fracture site may be tender on palpation. In more advanced fractures, a subperiostal nodule may be felt on palpation.
Findings from imaging investigations
A problem with an x-ray is that a period of 2 weeks to 3 months is required after symptom onset before any changes can be visualised http://www.dynamed.com/condition/stress-fractures-of-the-foot-and-ankle#IMAGING_STUDIES. In long bones a narrow callus is seen at the site of the fracture (on the exact spot where tenderness is felt on palpation; picture 1). In cancellous bone, sclerosis is usually not seen until after 4 weeks.
In the pelvis, callus at the narrowest point of the pubic arch
At the inner edge of the femoral neck, a sclerotic band perpendicular to the trabecular structure of the bone
Callus at the tibial or femoral shaft
Horizontal sclerotic band usually in the medial condyle of the tibia near the epiphysis
In the calcaneus, a sclerotic band perpendicular to the trabecular structure of the bone
MRI should be considered when it is necessary to reliably exclude or diagnose a stress fracture (risk of dislocation due to fracture) or the origin of pain needs to be identified quickly in an athlete or military conscript in order to assess the feasibility of further exercise or training.
Based on the MRI findings, osseous stress reactions may be classified according to the severity grade to stress osteopathies (grades I-III) and stress fractures (grades IV-V).
MRI to detect stress-induced bony changes in symptomless exercise devotees “just to be sure” is not recommended, because such changes detected by MRI in symptomless physically active people do not require treatment.
Diagnosis
Clinical diagnosis is based on a typical history and on the findings of a physical examination (tenderness on palpation).
However, clinical diagnosis without imaging studies is not reliable.
The diagnosis may often be confirmed with imaging studies.
A normal x-ray finding will never exclude a stress fracture, but it is a useful tool in differentiating between a stress fracture and, for example, bone cancer.
In cases of suspected stress fracture of the femoral neck or shaft, a reliable radiological diagnosis should be obtained immediately after symptom onset (risk of dislocation).
Investigations and differential diagnosis
An x-ray is required during the healing process (2-4 weeks after symptom onset) at the latest, particularly if symptoms persist despite exercise avoidance (to rule out bone tumours).
In cases of suspected fracture of the femoral neck or shaft, imaging studies are required at an earlier stage.
If the pain persists or the diagnosis is uncertain, the x-ray should be repeated every 2-4 weeks (does not refer to possible fractures at dislocation-prone sites). Alternatively, the patient may be referred for a magnetic resonance imaging scan.
Calcaneal stress fracture is painful when pressure is applied to the sides of the heel, whereas pain of plantar fasciitis is experienced when pressure is applied to the bottom of the heel.
In shin splints (medial tibial stress syndrome) Treatment and Prevention of Sports Injuries the pain has often been present during exercise for some time, even for years. The pain may be intermittent in nature. The pain is typically situated at the medial edge of the tibia. In the diagnostics of shin splints, measurement of compartment pressure may be used.
Crutches may be used if the pain is severe or the fracture is associated with a risk of dislocation. Crutches may be used if the pain is severe.
Local steroid injections or massage are not indicated.
Plaster casts are rarely needed in stress fractures.
Healing time is dependent on the stage when treatment was initiated (i.e. repetitive loading and strain ceased or was reduced). Initial bone changes diagnosed at an early stage with magnetic resonance imaging will heal more quickly than more advanced changes or fractures already visible on X-rays.
The severity grade of stress osteopathy or a stress fracture as assessed by MRI may be used to plan the period of strain and loading avoidance necessary for the treatment. This plan is also determined by the anatomical location of the lesion.
The healing of bone changes diagnosed at an early stage will only need 2-4 weeks of exercise avoidance. However, advanced changes may need as long as a trauma-induced fracture to heal, depending on the anatomic location of the injury.
Exercise is allowed when pain is no longer experienced during weight bearing and physical exertion and not on palpation either. Attention must also be paid to revising the patient's training programme.
Anti-inflammatory drugs are not recommended when exercise is resumed.