Stress fractures are one of the most common, and potentially serious, overuse injuries. A stress fracture is an incomplete fracture that can occur anywhere in the body, and are typically caused by repetitive forceful actions. In contrast, most other types of fractures are caused by a single, direct, traumatic impact.
Stress fractures usually occur in weight-bearing bones, and are commonly seen in the metatarsals of the foot, bones of the ankle, shins (tibia), knees, and hips (the neck of the femur is one the worst stress fractures). Stress fractures are often caused by repetitive activities such as running, dancing, soccer, or any sport that involves high levels of repetitive actions. Stress fractures can eventually lead to a complete fracture.
How the injury occurs
Your body is continually remodeling your skeletal system based on the stresses that are placed upon it. This remodeling process gives your body the ability to handle increased loads without further injury. The problem arises in that your body can only adapt to these stresses at a certain rate, and there is a finite limit to the amount of stress to which it can adapt. Injuries to the bone (microscopic fractures) occur when increased stress is placed upon your body too quickly, or when too much load is applied.
In more technical terms, stress fractures occur in the early stage of bone remodeling whenosteoclastic reabsorbtion of bone, outstrips the osteoblastic development of new bone. This results in a weakened bone that is susceptible to injury. Osteoblasts and Osteoclasts control the amount of bone in your body:
· Osteoblast - Osteoblasts are cells which are responsible for bone formation. These cells produce osteoids, that are composed primarily of Type I collagen.
· Osteoclast – Osteoclasts remove bone (reabsorb bone) by removing its mineralized matrix and breaking up organic bone.
Two Common Types of Stress Fractures
· Low-Risk Stress Fractures– An athlete can often heal these injuries by reducing activity, focusing on cross-training, nutritional supplementation, and a programs of conservative care accompanied by appropriate rehabilitation exercises.
· High-Risk Fractures – These fractures often occur on the tension side of a bone. Typically, these type of stress fractures do not respond well to any weight bearing activities or stresses, and require a non-weight bearing cast or complete immobilization to heal. In advanced cases surgery may be required to complete the healing process. Typical high risk areas include: Medial malleolus, navicular bone, fifth metatarsal, and the femoral neck.
You will need to consult a qualified medical practitioner to determine if a stress fracture is high-risk or not.
Risk Factors for Stress Fractures
Many factors can result in stress fractures including:
- Faulty or worn-out equipment such as:
- Using worn-out running shoes, worn-out point shoes for dance, or other defective supports.
- Using the wrong type of support in your shoes such as a supinator using a shoe that correctsexcessive pronation. It is important to seek someone with expertise in your sport to fit you with the proper shoes.
- Training errors such as:
- Sudden increases in frequency or duration of training.
- Training while in a state of exhaustion.
- Poor training techniques.
- Amenorrhea or the absence of menstrual bleeding results in loss of bone mass at a similar rate to that experienced by post-menopausal women (up to 5% per year). This makes them very susceptible to stress fractures.
- Restrictive diets that results in an inadequate supply of essential nutrients or calories, and can have a negative effect on bone density.
- Muscular weakness or muscle imbalances.
- History – Patients who develop stress fractures often have a history of pain that is brought on by physical activity, and reduced pain with rest. There is usually an accompanying history of recent increases in physical activity.
- Palpation – Touching the affected area (around the stress fracture) often elicits localized tenderness directly over the bone. Swelling over the area and redness is also commonly observed. Often there will be tenderness to percussion over the area.
- Pain – Unfortunately, the pain pattern of a stress fracture may not provide a direct indication about the actual presence of a stress fracture. The pain from a stress fracture is usually well localized, but in some cases, can be spread out over a larger area.
- Note: In the case of a femoral neck stress fracture (seen in runners/dancers or high impact athletes) the patient will feel groin pain that becomes worse with any activity (including walking) and that gets better with rest. This can become a very serious stress fracture if it transforms into a complete fracture. In such cases, the head of the femur can die due to lack of blood supply caused by the fracture.
- Tuning Fork – The vibrations of a tuning fork have been used as an indication of a stress fracture. Some practitioners dispute this test, but it may give the practitioner an indication that further diagnostic tests need to be performed.
- X-rays – Diagnostic X-rays are often not very good at finding a recent stress fracture. A stress fracture may not show up on the X-ray for 2-3 weeks. Despite this, an X-ray is one of the first diagnostic procedures that should be performed. If possible an MRI, or bone scanshould also be performed, these procedures are much more definitive than an X-Ray.
Treatment Considerations: Keep the following points in mind when treating stress fractures.
What Not To Do for Stress Fractures
Certain treatments and behaviors will exacerbate, or inhibit the healing of your stress fractures, including:
- DO NOT USE NASID’s – These medications inhibit bone healing and mask pain symptoms. Unfortunately many athletes, especially professional dancers, use large doses of NSAID’s.
- Ignoring a stress fracture - A stress fracture that is ignored could turn into a complete fracture, which then requires surgery, resulting in a long healing time. Bottom line, you will never get over a stress fracture by just ignoring it, it will only get worse until even minor motion becomes extremely painful.
What To Do to Treat Stress Fractures
The following has been found to be effective in dealing effectively with stress fractures.
- Prevention – The best way to treat this injury is to avoid it in the first place.
o Training – No matter which sport or activity you are involved in (running, dance, etc.) be sure to increase your distance, frequency, or intensity gradually over a period of time.
§ Focus on the quality of your training, not just quantity. Adequate rest goes a long way in preventing a stress fracture. Rest is an essential training component for avoiding injury and stress fracture.
§ Do not train when you are exhausted, higher levels of injuries occur when in states of exhaustion.
§ Make Your Bones Strong (preferably before the injury occurs).
A key point here is that you can only make deposits of calcium (and other minerals) into your bone bank up until age 25. After age 25, you need to take daily calcium to prevent unnecessary withdrawals from your bones. Note of interest: Calcium deficiency is a prerequisite for a stress fracture. 98% of Adolecent dancers are calcium deficient (Harkness Centre for Dance Injuries 2010).
o First consider the composition of your bones:
§ 70% minerals (calcium phosphate, magnesium, sodium, potassium, fluoride, chloride). This bone matrix of mineral is called hydroxyapatite. You need all of these minerals. It pays to focus on good dietary habits including the right amount of supplementation.
o Maintain your calcium levels:
§ Children under 9 years of age require 800 mg. per day. If you are between 9 - 50 years old, you need 1300 mg of calcium per day. Those over age 50 require at least 1000 mg. of calcium per day.
§ 70% of your bones are made up of minerals (hydroxyapatite). The best way to ingest calcium is through a complete Bone Matrix supplements. We often recommend that our patients take MCHA to meet their nutritional requirements.
§ After the Stress Fracture has Occurred - The time frame for recovering from most lower-extremity stress fractures is between 8 to 17 weeks. This time frame will be much longer if the area is not given adequate time to heal. The good news is that most stress fractures respond well to conservative therapy and do not require surgery (if the stress fracture is not ignored).
o Initially, weight bearing exercises must be eliminated with any lower-extremity stress fracture. This is essential to allow the bone to heal and complete the normal remodeling process.
o An air cast (pneumatic walker/walker boot) or crutches is often recommended during the initial stages of injury. The air cast will often be used for 4 to 6 weeks depending on the speed of healing.
o Cross-training is essential to speed the recovery. Swimming, cycling, and routines that do not involve weight bearing are often recommended. The patient should also continue with upper extremity exercises.
o A slow rate of return to activity should be implemented since introducing weight-bearing exercises too soon will increase the duration of the injury. As a general rule, once the area is completely pain-free, light walking can be resumed.
o Rehabilitation programs need to focus on several key factors (flexibility, strength, endurance, balance, propiroception, and alignment). This also includes addressing any weaknesses in hip or proximal stabilizers.
o Custom made orthotics may also be useful in helping to reduce biomechanical stresses on the affected area (Available through Kinetic Health).
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