Femoral Stress Fractures
Stress fractures are injuries that occur when repetitive and excessive stress on a bone is combined with limited rest. This leads to muscle weakness and a lower shock absorbing capacity of the leg and in turn can lead to bone damage.
Stress fractures of the femur are relatively uncommon, and data from the literature suggest that they constitute only 2.8–7% of all sport related stress fractures.
The femur is the longest bone in the body, connects the pelvis to the lower limb and is the sole bone of the thigh.
The femur consists of a head, greater and lesser trochanter, shaft, and lateral and medial condyles. It is also the attachment point for all muscles that help to control the hip and knee joints.
Stress fractures occur in bones that undergo mechanical fatigue. They are a consequence of exceeding repetitive submaximal loads, which creates an imbalance between bone resorption and bone formation.
These fractures usually begin in locations of great stress. When the microscopic crack is not given enough chance to rest and repair, but instead subjected to further repetitive loads the crack increases in size.
This increase in damage can cause the bone to break on a macroscopic level.
Stress fractures may be due to multiple factors including activity level, bone quality, anti-inflammatory drugs, radiation, nutritional status, osteoporosis, imbalanced hormones, sleep deprivation, and collagen anomalies.
The frequency of stress fractures is dependent upon the composition of bone, adjacent muscle attachments, blood supply, systemic factors, and the mode of athletic activity. Other possible risks include age, sex, footwear, and training regimen. High level female athletes who are inclined to the athlete triad (amenorrhea, eating disorders, and osteoporosis) and male endurance athletes who have unusually low levels of sex hormones are also at risk for stress fractures.
Signs and Symptoms include – deep aching discomfort in the region, pain increases with activity and improves whilst resting, localised tenderness over the bone, weightbearing and hop test reproducing pain, positive fulcrum test and aching at night.
Femoral stress fractures are a very treatable pathology and it does require immediate rest from repetitive loading. The treatment protocol is split into 4 phases, which compose the rehabilitation program. Each phase is 3 weeks long and graduation of each phase comes with a negative stress testing (only performed by your therapist) and will be guided by you therapist. If the stress test is positive and pain remains then the phase is repeated until pain free.
Phase 1 (symptomatic):
· Minimal to no weight bearing through affected leg – depending on the severity this may include a period of time on crutches.
· Complete rest from all weight bearing and muscle engaging activities – daily walking (i.e. around work) is allowed.
· No stretching or strengthening exercises during this phase.
· Avoid any activity that increase load through the leg, i.e. take the lift, not stairs. Minimise weight bearing exercise as much as possible.
· This is the most critical phase to get right, if you don’t, you can’t progress to the next phases.
· Emphasising the rest phase is critical.
Phase 2 (asymptomatic):
· Return to normal walking – up to 20 minutes
· Return to swimming
· Upper body weights (non weight bearing à in seated position)
· Non weight bearing core exercises
· This is the second most critical phase, again if you don’t get it right no progression to the next phase
Phase 3 (basic):
· Upper and lower body weights (non weight bearing – build into weight bearing)
· Return to run program starting at level 1 – straight line only – build through levels
· Cycling on a stationary bike – build through intensity
Phase 4 (Resuming):
· Return to 40-50% of normal training load
· Increase training load by 10% per fortnight
Generally it takes 12-18 weeks for a full return to basic training. If the hop test (between phases) fails, i.e. is still painful then you restart that phase, so strict adherence to the program is essential.
If not treated correctly femoral shaft stress fractures are well known for complications and difficulties such as:
1. Delayed healing
2. Complete fracture and displacement
3. Symptom recurrence
Compliance with this program is critical and the relative rest (following the above program) period of 12 weeks is the absolute minimum.
Tips to reduce the onset of femoral stress fractures include:
1. Running technique – when running longer distances make sure to land with a mid foot to forefoot loading pattern, increasing cadence and focus on gluteal activation.
2. Maintain strength in the short hip external rotators and the gluteals to reduce the shock absorption through the femur.
3. Ensure you are using correct footwear to optimise shock absorption.
4. Ensure you are engaging in adequate rest periods to allow the body ample opportunity to recover from repetitive bouts of loading.
So that’s a brief overview of how femoral stress fractures occur, If you have questions or comments feel free to e-mail us at firstname.lastname@example.org and we will be happy to answer them for you.
If you think you may already be suffering from stress-related pain, then addressing it sooner rather than later is crucial. So, if you want relief now, call us on (08) 9486 8653 and we will arrange an appointment for you.