Lower limb pathology flashcards final
What occurs in the bone due to repetitive excessive stress
Bone resorption by osteoclasts happens at a faster rate than bone remodelling by osteoblasts
What are the three stages of stress fractures?
Crack initiation - normal and occurs in areas loaded with tensile stress
Crack propagation - loading continues at a frequency/intensity that means new bone cannot be laid down quickly enough and multiple cracks coalesce
Complete fracture - if the area continues to be overloaded a complete fracture occurs
What are the most common areas for stress fractures and why?
The areas that are loaded most during movement:
- Tibia
- Distal fibula
- Navicular
- Sesamoid bones of big toes
- Base of 2nd - 4th metatarsals
What are the most common areas for stress fractures to progress to full fractures and why is that?
Anterior tibia
Navicular
Medial malleolus
5th metatarsal
Sesamoid bones
Lower relative vascular supply and increased tensile stress in these areas
What are some intrinsic factors for stress fractures and what questions might you ask in a subjective
Being female
Nutritional deficiencies of calcium or vitamin D - ask if someone has had any menstrual changes recently
Steroid use - decreases remodelling and calcium absorption and increases bone resorption
What would be the usual subjective findings from a patient with a stress fracture?
Changes to activity/training
Focal pain
Deep ache initially easing with rest
Progresses to include resting and night pain and pain that comes on earlier and earlier into activity
What would you do in an objective assessment if you suspected a stress fracture?
Palpation - tap with a tendon hammer over common stress fracture areas looking for pain/tenderness
Hop test - painful = positive
Potential painful ROM
What imaging might you use for stress fractures?
X-rays: They are usually not sensitive enough but are more cost-effective and widely available
MRI: Gold standard, increased sensitivity and are usually use if the area is at high-risk of developing into a full fracture
How would you treat a stress fracture?
Cease activity - crutches and NWB to give time for bone remodelling
Painkillers - not NSAIDs so not ibuprofen as they prohibit prostaglandin synthesis which can reduce bone healing
Management and loading is based on symptoms, the area should not been reloaded until pain on WB is removed
Splinting and boots will only remind the person of their need to rest
What would you advise for risk management for someone who has experienced a stress fracture
Progress gradually (10% increase weekly)
Supplements for deficiencies
Strength training to improve bone density
Decrease in load-bearing activities if possible i.e. swimming
Remove NSAIDs and steroids completely if possible
What is the main theory for the pathophysiology of MTSS and why does this happen?
Inflammation of the periosteum of the medial tibia
The flexor digitorum longus and soleus muscles attach onto the posteromedial border of the tibia
Activities that overuse these muscles can cause traction injuries on this part of the tibia and these include running during the toe off phase
What is a theory additional to periostitis for MTSS
As the muscle works, it provides more stress on the bone as the muscle becomes unable to oppose the bending movements caused by force through the foot at an angle. This means that bone remodelling occurs, the osteoclasts responsible for resorption exceed the activity of osteoblasts which lay down bone forming cells which can cause pain and lead to a stress fracture.
What would you expect from the subjective findings for someone with MTSS
A change to activity of some sport occurring just before onset of injury i.e. intensity, route/terrain, shoes etc
Pain presentation is linearly at the medial tibia, it increases with loading and decreases with rest, ranges from a dull ache to a sharp pain
What objective assessment would you do for someone with suspected MTSS and what would you expect to find
Single leg hop test - slapping sound due to weak eccentric plantarflexors due to fatigue, potential pain but not severe which can help to distinguish it from stress fractures
Palpation - feel along medial tibial border for tenderness and tap with a tendon hammer
ROM and resisted movements - usually full and painless but if very severe, there may be pain on repeated plantarflexion and inversion
What imaging would you use for MTSS
MRI - shows periosteal oedema which is a sign of early MTSS and MRI provides a high sensitivity of 88%
X-rays are unspecific
Bone scintirgraphy = 74% sensitive and shows linear increased uptake of bones
You would ultimately not often perform imaging for MTSS as you would be fairly confident on a diagnosis from your subjective and objective histories so imaging wouldn’t change your management
