Stress Fractures

Stress fractures are all too common in the sporting world. In simple terms, they represent our skeleton failing to absorb the loads that are placed upon it. This causes structural fatigue, pain, impaired performance and can in some cases lead to a complete fracture. Stress fractures can lead to long periods away from sports and activities; as a result, management and prevention are key factors.

Pathogenesis

Our bones are constantly getting remodelled and repaired as a response to the stress they are placed under load. This stress can lead to micro trauma of the bone which is then repaired by the cellular components of bone.

A stress fracture will occur when the bone can’t repair fast enough for the amount of damage it is sustaining. The following are three ways in which stress fractures can occur.

1. an increase in the applied load or the number of applied stresses (too much load);
2. inadequate recovery time between sessions (loading too soon); or
3. application of normal loads to weakened bones (low bone density or osteoporosis).

There are a variety of other factors that can lead to a stress fracture such as volume, intensity and the surface you train on, the amount of calcium or calories in your diet and hormonal factors.

Epidemiology

Stress fractures are most common in the lower limb with younger people more commonly affected. The average time to return to sport or activities is around 3 months making stress fractures considered severe injuries.

History

The onset of symptoms is normally insidious, meaning that the patient was not aware of a particular event or time when the injury occurred. There is often no onset of trauma with pain subsiding when the patient is at rest only to return again when they resume activity.

Like with most injuries, there are intrinsic and extrinsic risk factors. Intrinsic covers things like;

Gender – Women are more likely to sustain a stress fracture than men.

Endocrine and hormonal function – factors such as oestrogen levels are an increased risk of stress fractures in women.

Bone Density – low bone density can lead to stress fractures due to less bone strength

Joint mobility – the way in which the body can move has been linked towards developing stress fractures, reduced range of movement at a joint can lead to altered loading and higher rates of stress on certain areas.

Dietary habits – restrictive eating habits or eating disorders can lead to poor reabsorption for the bone and in turn lead to weaker bone more prone to fracture.

Extrinsic risk factors include things like

Training factors – increases in load, volume, intensity, duration. Sudden changes are the biggest risk factor in training error.

Mechanical factors – this means things like hard surfaces such as pavements or shoes that aren’t offering the right support.

Age – Your age can determine your bone density. Older people tend to have a lower bone density and children and adolescents haven’t reached peak bone density yet.

Examination

There are a number of things an osteopath will look for when examining for a stress fracture. The main feature of a stress fracture is the localized tenderness at the site of the injury followed by swelling. Some joints/bones are difficult to examine so there are a number of tests your osteopath might ask you to do such as steadily increasing activity from calf raises to jogging and seeing if they reproduce pain.

Investigations

In the event of their needing to be any further investigations there are a number of options available depending on the bone injured and the situation in which it occurred. An X-ray, CT scan, Bone scan, MRI and dexa scan are all options.

Treatment

The most important factor here is a period of reduced loading. Not necessarily non-weight bearing but just a period where there is some activity modification. E.g cycling instead of running.

Relative rest

This refers to the patient or athlete being able to maintain a certain level of conditioning while simultaneously allowing the fracture to heal optimally. A conditioning /rehabilitation plan has specific requirements including;

Ø  An accurate diagnosis – this is most important as it allows us to outline an effective rehabilitation plan.

Ø  Identifying possible contributing factors – this involves intrinsic and extrinsic factors that we can address in the rehabilitation plan.

Ø  Initial management – this phase is very detailed but in summary it involves some form of activity modification initially, then looking to manage possible contributing factors. Moving onto maintaining physical condition before looking to optimise tissue healing.

Ø  Return to sport/lifestyle – Again, another detailed area involving returning to activity, altering the load through the injured limb, gait retraining, before building a loading plan.

Ø  Specific conditioning – other forms of exercise can be trained here while monitoring strength, flexibility, proprioception and neuromuscular deficiencies.

Ø  Sports/Lifestyle specific retraining – here we incorporate specific drills and exercises.

Ø  Return to sport/lifestyle – here we need to way up a number of factors. Examples include risk vs reward, previous injury profile and the patients individual goals.

Prevention

In order to help prevent stress fractures it’s important to be able to identify any possible risk factors involving things like strength, footwear, floor surface, nutrition and hormones.

Additionally, gradual progression of activity should be implemented to allow for bone adaptation.