Stress Fractures in Shins and Lower Extremities
Lower extremity stress fractures are common injuries in the world of sports especially in athletes whose sports require a significant amount of jumping and running. According to Bahl and Maehlum (2004), up to 50% of all stress fractures occur in the tibia (shin) or fibula (two bones of the lower leg).
What is a stress fracture?
A stress fracture is a partial fracture in a bone that is caused by repetitive loading over time. Most fractures have an acute onset meaning that there was one mechanism of injury that caused the fracture.
Stress fractures are unique in that the bone breaks down over time causing a small partial fracture within the bone. Unlike most acute fractures in which the fracture is all of the way through the bone with an immediate onset of pain and associated functional disability, an athlete with a stress fracture may not know they have a fracture.
Although painful, some athletes may continue to participate with a stress fracture believing that the pain they are feeling is related to a muscle and/or tendon injury rather than to a bone injury. However, if left undiagnosed and untreated, athletes with stress fractures may run the risk of transitioning from a partial stress fracture into an acute fracture.
Who gets stress fractures?
Athletes in a number of sports may have a higher risk for lower extremity stress fractures because of the amount of running and/or jumping required for their sport. The sport with the highest incidence of lower extremity stress fractures is track and field, specifically the distance runners.
Stress fractures of the tibia and/or fibula can also be seen in athletes in the sports of basketball, volleyball, soccer, baseball and softball. Stress fractures are seen in athletes in these sports because of the amount of jumping and/or running involved, the surfaces that the athletes compete on, and the types of shoes worn.
What are the classifications of stress fractures?
Stress fractures are generally classified as either noncritical or critical. Noncritical fractures are typically located in the medial tibia and the fibula. They are classified as “noncritical” because they heal well with the athlete usually returning to sports within six to eight weeks.
Critical stress fractures are those that do not heal well and continue to have a nonunion of the bones even after the recommended period of rest. These fractures may need to be surgically repaired to encourage and enhance the healing process. These fractures include stress fractures to the anterior tibia (apparently due to poor local blood supply) and to the distal tibia (medial malleolus).
What are the signs and symptoms of a lower extremity stress fracture?
Athletes with stress fractures tend to complain of an acute onset of pain most often after a long training session. The athlete will not have a history of a single mechanism of injury, but will complain of a more gradual onset of pain over time.
The athlete may complain of point tenderness directly over the stress fracture site. The pain may diminish with rest, but will return with activity. The pain may increase as the activity level increases but especially on weight-bearing activities (jogging, running, jumping, and landing).
One symptom that is unique to stress fractures is that the athlete may experience an “aching” or “throbbing” pain late at night when the athlete has quieted down for the day.
The athlete may also experience swelling over the fracture site with associated heat radiating from the area due to the amount of biochemical activity in the area. The heat can be detected by running the back of the hand over the length of the tibia or fibula. If there is a hot spot and it corresponds with a point tender spot, the athlete should be referred to a sports medicine specialist for follow-up.
How is a stress fracture diagnosed?
Because a stress fracture is a small, partial fracture in a bone, it is not usually picked up through a routine x-ray. Because of this, a physician may order either a bone scan or an MRI.
Radionuclide scintigraphy (bone scan) is used to detect stress fractures because bones that are undergoing remodeling (as when a bone is healing from a stress fracture) will absorb the radionucleotide material more rapidly. Several hours after the patient is injected with the radionucleotide, the athlete is placed in a device that records the radioactive signals on film.
If the athlete has a stress fracture, the fracture will show up on the film as a dark spot. The value of the bone scan is that the scan can detect a stress fracture weeks before the fracture would show up on a routine x-ray.
Causes of stress fractures?
A number of factors that can cause stress fractures including:
• Sudden increase in mileage and/or training
• Insufficient shock absorption due to poor quality or worn out shoes
• Training on hard surfaces
According to Bahr and Maehlum (2004), stress fractures typically occur “between a few weeks and a few months after the athlete begins running training”. If weight bearing bones are loaded beyond what their capacity is to handle the force, the bone will break down and become injured.
It is important for athletes to understand that a sudden increase in training is one way to increase the risk of lower extremity stress fractures. The body needs time to adapt to the demands placed on it. If an athlete gradually increases his/her training over time, then the bones, muscles, and tendons will adapt to the loads and increase in strength.
However, if the athlete makes significant increases in the amount or distance in his/her training, the bones of the lower extremity will not be able to adapt to the stresses on the bones and the athlete may end up with an injury.
Along with sudden increases in training, the type of shoe that the athlete wears is another important factor in placing an athlete at risk for stress fractures. Shoes that are worn out or are poorly fitted may not provide enough shock absorption and stability for the athlete.
Ideally, depending on the sport, the shoe’s design should include a shock absorption component (especially in running shoes) specifically to reduce the amount of force transferred up through the foot and to the bones of the lower extremity. A good shoe base can reduce the forces on the bones thereby reducing the stress placed on the bones.
Unfortunately, some athletes are limited in what they can wear by their sport. Athletes in the sports of baseball and softball are required to wear cleats. These types of shoes typically do not have good shock absorption components placing these athletes at a higher risk for stress fractures.
Athletes, who may be limited in the type of shoes they wear by their sport, need to ensure that they bring a pair of running shoes to practices and change into them if extensive running is required. Athletes also have the option of purchasing insoles for his/her sport shoes if the original shoe is lacking in shock absorption ability.
Along with the shock absorption ability of an athletic shoe, the type of surface that the athlete trains on is another key component in placing athletes at risk for lower extremity stress fractures. Some athletes may not have a choice as to the surface they compete on (i.e., basketball, volleyball, baseball and softball).
If the surface upon which the athlete trains on is a hard surface (i.e., gym floor or dirt infield), the athlete needs to ensure that any extra cardiorespiratory training is done on a softer surface. If possible, the athlete can also train on a bike or in a pool to completely reduce all stresses on the lower extremity bones.
What can I do to prevent stress fractures?
The risk of stress fractures in the lower extremity can be reduced by focusing on the three primary causes: sudden increase in training, hard training surfaces, and poorly designed or worn out shoes.
Athletes need to be proactive in planning their training regimen to ensure that their goals are appropriate and that their training is gradual and progressive in nature. Athletes training for distance or to improve their cardiorespiratory system need to start slow and progress no more than ¼ mile per week.
This gradual progression will allow the weight-bearing bones to adjust to the training, gradually increasing their density and their ability to withstand greater loads over time.
Along with a gradual progression of training, athletes should carefully select the surfaces they train on (when possible). One surface that is specifically designed to absorb and decrease loads is rubberized track. This surface can be found on tracks at local colleges and some high schools.
If a rubberized track is not available, grass is another option. If the athlete is concerned about possible stress fractures in his/her lower legs, the athlete can completely off-load his/her legs and train on a bike or in a pool.
Last, because worn-out shoes are another cause of stress fractures, regularly replacing running shoes is one way to prevent stress fractures. Athletes should also invest in well-designed shoes specific for their sport paying close attention to the shock absorption quality of the shoe. This is one piece of equipment that is worth investing in as good shoes can prevent a lot of problems.
What is the treatment for a lower extremity stress fracture?
Treatment will depend on the classification of stress fracture. However, regardless of the classification of injury, the most important treatment is rest. Noncritical stress fractures of the tibia and/or fibula respond well to a period of non-weight bearing for six to eight weeks (fractures of the tibia) and four weeks (fractures of the fibula).
More Information: Read about sports injury treatment using the P.R.I.C.E. principle – Protection, Rest, Icing, Compression, Elevation.
It is important during this time that the athlete maintains their cardiorespiratory endurance by participating in activities that do not place any stress on the injured bone. Again, activities that do not place stress on the lower extremity bones include bicycling and water sports. With the physician’s permission, these activities can be performed safety during the recovery period.
While noncritical fractures may heal on their own, nonunion stress fractures may need surgical intervention to help the healing process. This may include surgical fixation with one of the following procedures:
• Plate and screws
• Medullary nailing of the tibia
• Excision of the fracture area
• Bone transplantation
• Excision and drilling of the bone
Although there are risks with any surgical procedure, these procedures have had good results (Bahr & Maehlum, 2004). With early diagnosis and treatment, most stress fractures have a good prognosis.
When Can I Return to Play?
Athletes may return to sport when they have been released by their physician to return to activity and when they are pain-free with weight bearing activities. To ensure that the bone has healed, the physician may order an x-ray to check the bone’s progress.
Find a Doctor who specializes in Stress Fractures:
- Anderson, M.K., Parr, G.P. & Hall, S.J. (2009). Foundations of Athletic Training: Prevention, Assessment, and Management. (4th Ed.). Lippincott Williams and Wilkins: Baltimore, MD.
- Bahr, R. & Maehlum, S. (2004). Clinical Guide to Sports Injuries. Human Kinetics: Champaign, IL.
- Brukner, P. & Khan, K. (2002). Clinical Sports Medicine (2nd Ed.). McGraw Hill: Sydney, Australia.
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