A stress fracture (also called a fatigue fracture) is a small crack in a bone caused not by a single blow but by repeated loading; it mostly appears in the bones of the leg and foot when activity has been increased over a short time [1][2]. The first X-ray is often normal; the basis of treatment is reducing the load on the bone, and healing usually takes 6 to 8 weeks [1][2][3]. Fractures of the femoral neck (hip), the front of the shin bone and some bones of the foot are regarded as high risk; surgery may be needed [3][4][5].
What is a stress fracture (fatigue fracture)?
A stress fracture is a small crack in a bone, or severe bruising within a bone [1][2]. Bone is constantly broken down and rebuilt; under repeated loading, when breakdown outpaces repair, the bone weakens [1][2]. In the early stage there is only swelling in the bone; if exercise continues despite the pain, the bone can crack [1].
What sets it apart from an ordinary fracture is how it happens: the repeated force that causes a stress fracture is not as great as the force in fractures that occur in an instant from a fall or a collision [2]. Fractures due to osteoporosis are also a separate matter: bone weakened by a tumour, an infection or osteoporosis breaks under normal load [3]. That subject is covered in the osteoporosis article on this site.
What causes a stress fracture?
The commonest cause is increasing physical activity over a short time; symptoms often appear 3 to 4 weeks after starting a new exercise routine or a new sports season [1][2]. It is common in running and jumping sports and in military personnel; long walks and marching are also among the causes [1][3][7]. The main factors that raise the risk are [1][2][3][7]:
- Training on hard surfaces such as concrete, or a change of surface
- Worn-out shoes that have lost their ability to absorb shock
- Low bone density or a low vitamin D level, osteoporosis, the menopause
- Eating too little for the energy used (relative energy deficiency in sport, REDs)
- Being female, older age and a previous stress fracture
Where do stress fractures occur?
Most stress fractures occur in the leg and foot, in the bones that carry body weight [1][4]. The shin bone (tibia) is the most commonly affected site; the navicular and metatarsal bones of the foot, the thigh bone and the pelvis can also be affected [3][4]. Fractures of the foot and toes are covered in a separate article on this site.
- Leg (shin bone): pain, tenderness and swelling at one particular spot; tenderness spread along the inner back edge of the bone with no swelling suggests medial tibial stress syndrome instead [3]
- Foot: most often the second and third metatarsals; there may be swelling on the top of the foot [2]
- Heel: the heel bone is the second most common site of stress fracture in the foot [2]
- Hip and thigh: depending on where the fracture is, it can cause pain in the hip, groin, buttock, thigh or knee [4]
- Lower back: stress fractures can also occur in the lumbar vertebrae [3]; spinal problems are assessed by the relevant specialty
What are the symptoms?
At first there is discomfort at one particular spot on the bone, felt only at the end of activity and for a short time afterwards [1]. The pain develops gradually, gets worse during weight-bearing activity and eases with rest [2]. If loading continues, the following may be added [1][2]:
- Pain throughout activity, with ordinary walking and during daily tasks
- Limping
- Aching in bed at night
- Tenderness when the bone is pressed
- Swelling, sometimes bruising
How is it diagnosed? Why can the first X-ray be clear?
The doctor asks how the symptoms began and about changes in your level of activity; on examination they press on the bone to see whether the tenderness is confined to one spot [1][2]. For fractures in the leg you may be asked to hop on that leg [1][4].
The first imaging test is an X-ray, but in the early period it is often normal: swelling in the bone cannot be seen on X-ray, and the crack is very fine to begin with [1][2]. According to one review, the sensitivity of X-ray is 10% at the outset; if an urgent diagnosis is not needed, the X-ray may be repeated after 2 to 3 weeks [3]. If suspicion remains, an MRI or a bone scan may be requested; both show the fracture earlier than X-ray does [2]. MRI is currently regarded as the most sensitive and specific test [4].
How does a stress fracture heal? Treatment
The aim of treatment is to reduce the load on the bone so that it can heal [1]. The activity that causes the pain is stopped for a time; activities such as swimming and cycling can be done meanwhile [1][2]. If walking is painful, a hard-soled shoe, a walking boot or crutches reduce the load further [1]. For some fractures a cast is applied, and it is usually removed after 4 to 6 weeks [2][7].
The patient information sources this article is based on do not list any cream or ointment as a treatment [1][2][7]. Wrapping the area lightly in a soft bandage, applying ice and keeping the foot raised are first-aid measures aimed at reducing swelling [2]. The American Academy of Orthopaedic Surgeons (AAOS) states that anti-inflammatory painkillers can help relieve pain and reduce swelling [1]; one review, however, advises using them with caution because some animal studies have shown that they may inhibit fracture healing; a pharmacist or doctor can advise on which painkiller is suitable [3].
The return to sport must be slow and gradual: once the doctor has given clearance, days of activity are first alternated with days of rest, and then the frequency, duration and intensity of exercise are slowly increased [1][2]. Returning to activity too soon can delay healing and increases the risk of the bone breaking completely [2].
High-risk stress fractures and surgery
The great majority of stress fractures heal without surgery [4]. Fractures at certain sites, however, are regarded as high risk because they may progress to a complete fracture, heal late or fail to unite; these include the upper outer part of the femoral neck, the front of the shin bone, the navicular and the fifth metatarsal [3]. A systematic review reports that the studies comparing surgical and non-surgical treatment are small and that the level of evidence is low [5].
- Femoral neck (hip): fractures in the upper part of the neck carry a greater risk of displacement and their management includes surgical fixation; most undisplaced femoral stress fractures heal without surgery in 8 to 14 weeks [4]
- Navicular: one of the fractures for which surgery is more commonly recommended [2]; in the review, return to sport averaged 16 weeks with surgery and 22 weeks with non-surgical treatment [5]
- Base of the fifth metatarsal: because its blood supply is poor, healing takes longer; return to sport is usually not possible before 12 weeks [2]. In the review the best results were obtained with surgery [5]
- Front of the shin bone: the results of non-surgical treatment were found to be unsatisfactory, while the role of surgery at the outset is unknown [5]
How long does it take to heal, and how is it prevented?
Stress fractures of the foot and ankle typically take 6 to 8 weeks to heal [2]. Healing usually takes at least 3 weeks, and for more severe fractures it can take 3 months or longer [1].
According to a Cochrane review, shock-absorbing insoles probably reduce the incidence of stress fractures in military personnel; stretching the leg muscles during warm-up has not been shown to have a significant effect [6]. The recommendations for prevention are [1][2]:
- Starting a new activity or sports season slowly; increasing time, speed and distance gradually
- Replacing worn-out sports shoes
- Alternating running and jumping with activities such as cycling and swimming
- Sleeping at least 7 hours a night and taking one full rest day a week
- A diet that covers the energy used and is rich in calcium and vitamin D
When not to wait
If you think you have a stress fracture, see a doctor as soon as possible; do not carry on exercising through the pain [1][2]. Assessment should not be delayed in the following situations:
- Groin, hip or thigh pain that increases with activity in someone who is running or in marching training: a stress fracture of the femoral neck can displace, so imaging is done urgently [3][4]
- Pain that continues with ordinary walking or when lying in bed at night, or a limp [1]
- A sudden increase in pain in a stress fracture that has already been diagnosed: the fracture may have broken completely and displaced [2]
- Pain or swelling that continues despite a few days of rest [2]
Frequently asked questions
- Are a fatigue fracture and a stress fracture the same thing?
- Yes, fatigue fracture is another name for a stress fracture: a small crack in a bone, or bruising within it, caused by repeated loading [1][2]. Fractures that occur under normal load in bone weakened by osteoporosis are a separate matter [3].
- Does a stress fracture show on an X-ray?
- In the early period it often does not; according to one review the sensitivity of X-ray at the outset is 10% [1][3]. If suspicion remains, an MRI or a bone scan shows the fracture earlier [2].
- Does a cream or a bandage help a stress fracture?
- Patient information sources do not list any cream as a treatment; a soft bandage is only a first-aid measure aimed at reducing swelling [1][2]. The basis of treatment is reducing the load on the bone [1].
This article is a general summary; diagnosis and treatment decisions are made by the doctor who examines you.
Sources
- Stress Fractures. American Academy of Orthopaedic Surgeons (OrthoInfo), n.d.. orthoinfo.org
- Stress Fractures of the Foot and Ankle. American Academy of Orthopaedic Surgeons (OrthoInfo), n.d.. orthoinfo.org
- Stress fractures: diagnosis, treatment, and prevention. American Family Physician (Patel DS, et al.), 2011. pubmed.ncbi.nlm.nih.gov
- Diagnosis, treatment, and rehabilitation of stress fractures in the lower extremity in runners. Open Access Journal of Sports Medicine (Kahanov L, et al.), 2015. pubmed.ncbi.nlm.nih.gov
- Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review. British Journal of Sports Medicine (Mallee WH, et al.), 2015. pubmed.ncbi.nlm.nih.gov
- Interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults. Cochrane Database of Systematic Reviews (Rome K, et al.), 2005. pubmed.ncbi.nlm.nih.gov
- Caring for a stress fracture. Gloucestershire Hospitals NHS Foundation Trust, n.d.. gloshospitals.nhs.uk
This article is general information and does not replace an examination or imaging. If you have symptoms, see a doctor.
More in this area
- Ankle fracture: cast or surgery, and when can you put weight on it?
- Broken bone healing time: when does the cast come off, what eases the itch?
- Plates and screws after a fracture: do they have to be removed?
- Muscle strains and tears: how to recognise one and how long it takes to heal
- Osteoporosis (bone thinning): how is it detected and how are fractures prevented?