Evaluation of a Painful Total Knee Arthroplasty Sarat Kunapuli, DO EASTERN OKLAHOMA ORTHOPEDIC...
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Transcript of Evaluation of a Painful Total Knee Arthroplasty Sarat Kunapuli, DO EASTERN OKLAHOMA ORTHOPEDIC...
Evaluation of a Painful Total Knee Arthroplasty
Sarat Kunapuli, DO
EASTERN OKLAHOMA ORTHOPEDIC CENTER
Introduction
• Over a 150,000 total knee arthroplasties performed annually. 1
• Pain after TKA – common observation in about 20% of patients post-op 1
• Revision surgery required for some of the painful TKAs
• Revision TKAs on the rise
• Clear understanding of failure mechanism required prior to considering revision surgery
Introduction• A good history – invaluable
• Must have a diagnostic algorithm to identify cause of failure
• If performing revision – verify cause of failure
Algorithm
Common and Uncommons
Common causes - Prosthetic loosening, Infection, Instability, Component failure, Patellofemoral disorders, Periprosthetic osteolysis
Uncommon causes - particulate-induced synovitis, patellar clunk syndrome, lateral patellar facet syndrome, soft-tissue impingement syndromes, fabellar impingement, popliteus tendon dysfunction, tibial component overhang, HO, cutaneous neuroma
Non articular causes - Hip disease (arthritis, avascular necrosis, fracture, etc), spine disorders, vascular disease (insufficiency, aneurysm, thrombosis), reflex sympathetic dystrophy, psychological illness
History
Symptoms prior to surgery Symptoms after surgery Onset Was it getting better and then it got
worse? Type of pain Inquire previous x-rays, operative notes,
lab work – avoids duplication
History
Physical Exam Analyze gait pattern – watch for coronal plane thrust –
indicative of malalignment or ligamentous instability
Careful exam of skin –erythema or warmth
Examine for point tenderness – may represent tendonitis, bursitis
Thorough neurovascular exam
Examine spine and hip to rule out causes of referred pain
ROM testing
Stability – check collaterals at full extension, 30 degrees of flexion, and 90 degrees of flexion
Check stability in sagittal plane
Psychological assessment if warranted
Lab Evaluation Mainly done to distinguish between septic and aseptic
etiologies
ESR and CRP preliminary
ESR usually elevated for 3-6 months after uncomplicated TJA
CRP – normalizes 3-6 weeks after TJA
If CRP and/or ESR elevated – aspirate
Cell count and differential and cultures ( WBC >1100 and PMN > 64% and CRP > 1 Ghanem et al. JBJS 2008)
If inconclusive – aspirate again
Investigate metal allergy if pertinent
Imaging
Standard weight bearing x-rays – AP, lateral and Merchant
Full length standing films to assess malalignment Bone scan – not used commonly but can help to
identify loose components CT scan – can be used to assess bone stock and
to assess femoral and tibial component rotation Flouroscopy – used to assess dynamic stability
Imaging
Imaging
Imaging
Imaging - osteolysis
Imaging - Flouroscopy
Imaging – CT scan
Treatment Do not do anything until you find an underlying cause
Once you do find a cause – verify intraoperativly
Revision surgery without underlying cause – high failure rate
Questions?