I thought I'd put together an overview & some clinical nuggets from the 'coal-face'
First up, I prefer to call them 'bone stress injuries' - majority don't have a # line on imaging & the language can be scary / nocebic for some
Pathophysiology & risk factors
Stress fractures-
Occur in normal bone that is placed under abnormal / persistent load & strain ('training / sporting error')
Insufficiency fractures-
Occur in bone that is under normal strain but is structurally vulnerable eg metabolic conditions
In reality, can be a combination of both to varying degrees - not 'black & white'
Special mention goes to RED-S which often underpins BSI in athletes - men & women!
Ask about relationship with food (past & present) & menstrial history - periods are a barometer of athlete health
At a granular level, bone physiology, its hormonal control & homeostasis is complex - but the fundamentals are pretty straight forward ⬇️
Grading
Fredericson classification originally created for Medial Tibial Stress Syndrome (MTSS) - now extrapolated to other BSIs
Is it helpful?🧐
I occasionally see high grade injuries with minimal pain - & low grade stress reactions with significant symptoms & functional loss
However, generally if cortical involvement with fracture line = significant injury & correlates with extended RTP / running timescales
A useful platform for discussion with patient around severity of injury and respecting the injury & realistic timescales
High vs Low risk BSI
Some stress #s need to be treated with extra respect & caution - see table
These are typically under sustained high strain coupled with relatively poor blood supply
These are more likely to go through delayed union & take longer to recover - or indeed even need early orthopaedic opinion - tension / lateral side neck of femur is a good eg
Keep them on your clinical radar & assess specifically for them - lower threshold for imaging
Presentation
Gradual onset with persistent impact activity - but occasionally patient describes acute onset pain/ 'crack'
Pain on impact / 'first step' - tendon conditions often ‘warm up’ - unusual with BSI
Some with lower grade BSI can often run through it, but ⬇️performance
Rest & night pain when high grade
Ache, throb at rest - sharp, shooting under load - pelvic & proximal femur BSIs can feel 'neural' & refer into lower limb
Description of loss of power output, control, heaviness
Nutritional & dietary modifications - eg improving macro / calorie intake in cases of low energy availability (LEA)
Vitamin D
Other adjuncts eg shockwave therapy, LIPUS - controversial
Rehab fundamentals
Return to running & load progressions guided by pain levels & function
Beware 'lag phenomenon' when assessing pain response / flare on⬆️load - delay over 2-3 days
Generally 12-16 weeks RTR
<8 weeks seems a recipe for recurrence & back to 'square 1'
Challenge 😤🙄 the small number of patients who have low levels of pain - or pain settles v quickly with early offload - but high grade stress radiologically
In these cases seems sensible to respect physiology & set arbitrary number of weeks before moving into RTR
Some clinicians might not agree with this & have a more pragmatic approach
@rwilly2003 paper has suggested that with MTSS, if pain free for 5 days can begin graded RTR
So clearly can't be rigidly prescriptive / recipe based - every patient different due to personal factors ++
Tips:
Time scales variable
Respect physiology
Not ‘one size fits all’
Step count?
Pragmatic approach to cross training
Parallel S&C programme
Education
Alter G – graded exposure?
Why aren't they getting better?
Compliance aside - misdiagnosis might be the cause -
eg rheumatological - enthesopathy with florid bone oedema
Osteoid osteoma tumour - eg proximal femur & calcaneum - here CT will help differentiate
Worsening medial groin pain radiating into lower abdomen & "womb" - no acute episode, pop or tear
Worst on explosive block drills; sprinting especially when fatiguing & losing form, dropping into hip & lumbar extension; core / abdominal S&C work
Can attain max 65% sprint performance
Exam - pain & weakness on isometric long leg squeeze & resisted crunches
NO pain on palpation through pubic symphysis, tubercle or adductor origin
MRI with groin protocol - marked symphysis pubis degenerative & erosive change (seen best on VIBE sequences - image) & pubic bone oedema
Common in athletes especially multi-directional sports
Do we consider injecting symphyseal cleft?🧐
POCUS - clear cut enthesopathy of rectus abdominus insertion as it blends with pre-pubic aponeurotic tissues at pubic tubercle
(what would have been called rec ab- add longs aponeurosis not so long ago)
Re-visiting MRI - possibly subtle changes in deep corner (arrow) but reported as normal (MRI flipped / rotated to mimic ultrasound plain)
Most cases are ‘common garden’ achilles tendinopathy
However, here is a selection of conditions I've seen over time in clinic which can masquerade & are worth considering if the picture is atypical or patient not progressing
1. Achilles enthesitis
🧐
Insertional heel pain, not mid portion
<45?
Psoriasis or inflam bowel disease?
LSp / gluteal pain?
Early morning stiffness & ‘inflammatory’ pattern?
Think spondyloarthropathy
💊
Trial of NSAIDs may be eye-opening
Early rheumatology referral?
2. Plantaris compression tendinopathy
🧐
Refractory to achilles loading programme over 3 months
Pain on pronation
Worse on dorsiflexion eg gradients
Medial tenderness
💉
USG injection at interface can help
Surgical resection if recalcitrant