1. Stress Fractures

2. Normal Anatomy Bone remodels under wolff’s law
Remodelling takes place via mechanotransduction
Remodelling is based on the force and load placed through the bone
If loading on a bone increases the bone will remodel itself to become stronger and resist the loading
If loading on a bone decreases the bone will become less dense and weaker due to the lack of stimulus
Remodelling occurs quickly in cancellous bone
Remodelling occurs slowly in cortical bone

3. Pathology
Partial or complete fractures resulting from repetitive and excessive mechanical stress on normal bone

4. Pathology Normal Stress Stress Reaction Stress Fracture
Load and stress applied to bone with adequate time to remodel
Bone remodels according to Wolff’s Law
Stress Reaction
Under repetitive loads without sufficient time to remodel bone will fatigue and fail
Osteoclastic activity is greater than osteoblastic activity
Results in microfractures
Stress Fracture
Continued stress results in cortical break

5. Mechanism of Injury
Insidious
Repeated stress or load e.g running

6. Risk Factors Intrinsic Female Low bone mineral density
Nutritional deficiencies
Hormonal irregularities
Leg Length discrepancies
Genu Valgum
Poor lower limb muscle mass
Extrinsic
Running or jumping sports
Rapidly increasing training program
Poor training surface
Running downhill
Poor training footwear
Smoking

7. Classification Location and type of the fracture predictive of healing
Compression stress fractures more likely to heal with conservative measures
Tension stress fracture usually require surgical intervention
Tension forces can displace fracture site creating instability

8. High Risk Fractures

9. Femoral Neck Stress Fracture
High morbidity in runners
Significant complications if missed
Fracture completion
Avascular necrosis
Arthritis changes
Anterior hip or groin pain worse with activity
Extremes of passive ranges of movement maybe painful
Superior aspect of the femoral neck
Tensile forces
Surgically managed
Inferior aspect of the femoral neck
Compressive forces
Can be managed surgically or conservatively depending on fatigue line

10. Anterior Tibial Shaft Stress Fracture
Tension type stress fracture
Poorly localised anterior leg pain
Risk of non-union
“dreaded black line” anterior tibia radiograph at middle-distal third junction of anterior tibia
Initially conservative but surgical management required 60% of the time

11. Navicular Stress Fracture
Common in athletes requiring a “push off” e.g sprinters, middle distance runners
Navicular avascular
Compression between talus and cuneiform
Vague, poorly localized foot pain of medial dorsum of the foot
Tenderness “N-spot” on the dorsal navicular
Can be managed conservatively if no cortical disruption present, otherwise surgically managed

12. Talar Neck Stress Fracture
Rare
Usually report a trauma

13. 5th Metatarsal Stress Fracture
Less common metatarsal fracture
Usually in the diaphysis on the lateral side and progresses medially
Tension type
Pain with weight bearing
History of trauma or change in routine/environment/footwear
Tenderness palpation
Surgery considered for
Failed conservative management
Displaced fracture
Elite athlete with need for early return

14. Low Risk Fractures

15. Femoral Shaft Stress Fracture
Usually proximal third
Insidious onset
Non-specific pain localised to the groin, thigh or knee
Conservatively managed

16. Pelvic/ Pubic Ramus Stress Fracture
Groin pain
Pain with single leg stance
Most commonly inferior pubic ramus
Conservatively managed

17. Fibula Stress Fracture
Diffuse lateral leg pain
Usually affect the distal third
Conservatively managed

18. Calcaneus Stress Fracture
Heel pain
Worse on running and jumping
Posterosuperior tenderness on palpation
Conservatively managed

19. 2nd -4th Metatarsal Stress Fracture
Most commonly 2nd and 3rd metatarsal
Forefoot pain on activity
Tenderness on palpation

20. Posteromedial Tibial Stress Fracture
Shin pain with weight bearing
Focal tenderness over posteromedial tibia
Occur posteromedial in the proximal or distal parts
Conservatively managed

21. Subjective Examination
Localized area of pain
Insidious onset
Occurs with activity that gradually gets worse
Advanced stages pain could be at rest
History of repeated activity

22. Objective Examination
Focal tenderness
Pain with percussion

23. Further Investigation
MRI
Bone scan CT

24. Management Management plan determined by location and risk of fracture
Guided by surgeon

25. Conservative Activity modification to a pain free threshold
“if it hurts to do it, then don’t do it”
Reduce risk factors
NSAID’s should be avoided
Gradually progress weight bearing activity as pain allows
Maintain general body conditioning, fitness and strength with pain free exercise
Roughly 4 – 8 weeks for adequate healing

26. Plan B
Surgical interventions depend on site

27. References
Aweid, B., O. Aweid, S. Talibi and K. Porter (2013). "Stress fractures." Trauma 15(4):
Gallo, R. A., M. Plakke and M. L. Silvis (2012). "Common leg injuries of long-distance runners: anatomical and biomechanical approach." Sports Health 4(6):
Kahanov, L., L. E. Eberman, K. E. Games and M. Wasik (2015). "Diagnosis, treatment, and rehabilitation of stress fractures in the lower extremity in runners." Open Access J Sports Med 6:
McCormick, F., B. U. Nwachukwu and M. T. Provencher (2012). "Stress fractures in runners." Clin Sports Med 31(2):