During revision total knee replacement, significant bone loss is encountered on the tibial side. According to the Anderson Orthopaedic Research Institute (AORI) classification, Type III tibial bone loss is characterised by:
- A Minor contained cavitary defect not affecting the implant support zone
- B Major segmental defect compromising one tibial plateau condyle
- C Major bilateral condylar defects destroying the tibial metaphysis and compromising both plateaux ✓
- D Defect limited to the tibial surface requiring only surface preparation
Correct answer: C. Major bilateral condylar defects destroying the tibial metaphysis and compromising both plateaux
Explanation
AORI Type III tibial bone loss involves massive bilateral condylar destruction compromising the entire tibial metaphysis. Type I involves minor contained defects; Type IIA involves a single condyle; Type IIB involves both condyles but the metaphysis is intact. Type III defects require structural allograft, metaphyseal sleeves or cones, or tumour-type implants for reconstruction.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.