FRCS Revision

This site is private

Enter the password to open the revision library.

Personal revision library · not clinical advice
FRCSRevision
Home / Knee / Knee radiography - views and postoperative films
Knee

Knee radiography - views and postoperative films

Radiographic views including weight-bearing, bilateral and early post-arthroplasty films.

10 questions 2 source pages

Images appear with the first question taken from each source page — tap a question to open it.

10 questions
Q1Describe the radiographic findings in this early post op TKR X-ray.▸
  • This is an early post op film: both femoral and tibial implants are fixed with cement, no wedge/stem
  • Patella replaced
  • Femoral component size small, not flushed with the condyle, no notching on lateral view
  • Tibial implant size optimal, no overhang
Q2What further imaging or measurements would you like after TKR?▸
  • Measure PE thickness
  • Long standing film for alignment
Q3What is checked on the lateral view of a post-TKR knee?▸
  • Notching of the anterior femoral cortex
  • Femoral component sizing and flushness
Q4What is a Charcot joint and what are the X-ray findings in the knee?▸
  • Progressive, noninfectious, destructive disorder of bone and joint with underlying sensory neuropathy
  • Destruction of the joint with subluxation
  • Periarticular bone debris
  • Increased bone density
Q5What are the differential diagnoses for a destroyed knee?▸
  • Infection
  • Advanced OA knee
  • RA
Q6What history and examination findings are relevant in a Charcot knee?▸
  • Hx: premorbid function, pain, instability, functional limitations, expectations
  • PE: sensation and proprioception
  • Difficult to differentiate from osteomyelitis
Q7How do you rule out infection in a Charcot knee?▸
  • Difficult to differentiate from osteomyelitis
  • Blood tests, WBC scan, aspiration, synovial biopsy
  • Bone scan both hot; WBC scan may be cold in Charcot
Q8What underlying causes of a Charcot joint should be sought?▸
  • DM
  • Syphilis (Argyle-Robertson pupil)
  • Hansen disease
  • Syringomyelia
Q9What is the management of a Charcot knee?▸
  • Limitation of activity and bracing
  • Surgery: key is to intervene at the consolidation phase
  • Fusion is classical: resect sclerotic bone (dead bone), apposition of bleeding bone; prolonged immobilisation >12 weeks
  • Recent trend towards TKR
Q10What are the issues with TKR in a Charcot knee and the reported outcomes?▸
  • Poor bone stock; soft tissue laxity --> instability; poor implant fixation --> 2/3 zonal fixation
  • TKR reported to give good pain relief; some say relatively contraindicated (high complication rate)
  • EFORT meta-analysis 2021: survivorship 85.4% (mid >5years to long term >10years)
  • Complication rate 26.4%: instability 24.0%, periprosthetic fracture 17.4%, infection 13.0%, ligament injury 10.9%, aseptic loosening 10.9%
← Knee osteoarthritis - assessment and indTKR principles, consent and anaesthesia →